Scottish Government

MANAGING INCIDENTS PRESENTING ACTUAL
OR POTENTIAL RISKS TO THE PUBLIC HEALTH:
Guidance on the Roles and Responsibilities of Incident Control Teams

Annex 3

National Health service in Scotland: Responding to Emergencies REVISED ANNEX J

INCIDENTS INVOLVING IONISING RADIATION

J1 INTRODUCTION

J1.1 The nature and scale of the required NHS response to an emergency involving ionising radiation will vary according to the particular incident, which might range from a major accident at a nuclear reactor to one involving a ruptured or misplaced medical or industrial radioactive source. Whatever the circumstances, and however minor an incident involving nuclear radiation might be, it is likely to generate immediate and widespread public concern and media interest. This Annex contains details of the special arrangements and procedures necessary for NHSScotland to deal with casualties, to protect people against harm from environmental contamination and to otherwise safeguard human health following an incident involving ionising radiation.

NHS Board Responsibilities

J1.2 NHS Boards are responsible for the preparation and maintenance of contingency plans appropriate to their area to provide:

J1.2.1 Treatment and care of casualties, including the identification through monitoring of anyone, injured or not, contaminated with radioactive material and its removal by decontamination.

J1.2.2 Advice to the emergency services, local and other authorities, the public and the media about effects of a radiation incident on human health, and of counter-measures to those effects.

J1.2.3 NHS Boards are responsible for the administration of and distribution of stable iodine in co-operation with the local authority and other agencies that could assist.

J1.2.4 Co-ordination of NHSScotland arrangements with those of operators of nuclear sites, of others whose business involves handling radioactive materials, the emergency services, regulatory and other authorities through participation in local inter-agency emergency management machinery.

J1.2.5 Notification of, and keeping informed, SEHD and other NHS Boards in the event of an incident.

J1.2.6 Initiation of measures to assess longer term health effects including confirmation of calculated assessments of population exposure by sample validation monitoring, and by monitoring individuals who have reason to suppose they have been exposed to higher than average levels of contamination.

J1.2.7 (for minor incidents) Provision of assistance under the NAIR scheme ( Appendix 1, paragraph 1J.8).

J1.2.8 Ready access to the appropriate specialist clinical and radiation protection expertise and advice which any of the above might require.

J1.2.9 Participation in regular exercises to test responses to a nuclear incident that might affect people in their NHS Board area.

J1.3 The following NHS Boards should act as "lead Board" in relation to the development, exercising and implementation of emergency plans relating to the major nuclear establishments in their areas. Lead Boards should maintain liaison with the site operator on health aspects of planning, and should consult and keep informed other NHS Boards affected, the Scottish Ambulance Service and SEHD (NHS Emergency Planning Unit).

J2 PLANNING BACKGROUND

J2.1 The Government Department which will act as "Lead Department", and thus co-ordinate Central Government support to the response, will depend on the nature and circumstances of the particular incident. So too will overall responsibility for the co-ordination of action at the scene and in its vicinity. The arrangements that apply in particular scenarios are outlined at Appendix 1 to this Annex.

J2.2 Whatever the scenario, and whichever UK Government Department is the Lead Department, the SEHD retains its overall responsibility for the management of NHSScotland, and for providing advice to other Departments, to Ministers and, when necessary, directly to the public on the health implications of any emergency. In the event of a major nuclear emergency, The Scottish Executive would open the Scottish Executive Emergency Room (SEER) to provide a focal point for co-ordinating the response of all Scottish Executive departments involved and would be assisted as necessary by other Government and non-Government agencies, including the National Radiological Protection Board (NRPB).

National Radiological Protection Board (NRPB)

J2.3 The National Radiological Protection Board (NRPB) provides independent advice to Government, other agencies and the public on radiation protection. In the emergency planning context NRPB advises on the radiological consequences of foreseeable accident scenarios and on the implications for emergency planning. NRPB specifies and advises on Emergency Reference Levels (ERLs) which are primarily intended for use in the development of emergency plans, although they may also be useful following an incident to assist in determining whether or not particular emergency measures are indicated. (See Appendix 3.) In a post-incident situation NRPB assesses and advises on the radiological consequences of the incident and co-ordinates monitoring information outside any site emergency plan area. NRPB may be able to provide support to NHS Boards in their responsibility for radiation monitoring of certain sections of the affected population following an incident.

J2.4 NRPB is also responsible for the administration of the NAIR scheme (see Appendix 1, paragraph 1J.8).

Plans for Specific Contingencies

J2.5 Site operators and users of radioactive materials are responsible for ensuring the safety of workers and the public so far as is reasonably practicable and for preparing contingency plans to deal with incidents. Specific plans are in existence for all major civil and military nuclear sites and for certain other contingencies described at Appendix 1. Site plans should identify a Detailed Emergency Planning Zone (DEPZ) closely surrounding each installation within which arrangements to protect the public should be planned in detail. Plans need to be capable of responding to incidents, which although very unlikely, may extend beyond the DEPZ. The exact response must be based on an assessment made at the time and the response may make use of plans made to deal with other major incidents.

J2.6 Formal arrangements exist at major nuclear sites for consultation between site operators and local interests including NHSScotland. Site operators need to be aware of relevant NHSScotland arrangements so that these can be described in their emergency plans. NHS Boards with a nuclear installation within their areas need to be familiar with all aspects of the site emergency plan and ensure that the involvement of the health services is taken into account. The lead NHS Board (see J1.3 above) should be represented on the site Emergency Planning Co-ordination Committee (EPCC) or its equivalent and take an active part in its proceedings.

J2.7 It should be noted that differences of terminology exist in the arrangements for managing civil and military nuclear incidents; the basic arrangements are, however, broadly similar. At a major civil nuclear establishment, initial implementation of the site's emergency plan will be undertaken at the Site Emergency Control Centre (SECC). The operator is then required to activate an Off Site Facility (OSF), well clear of the plant, for overall incident management. Operation of the OSF is co-ordinated by the police. The lead Government Department would, on the advice of the Chief Nuclear Inspector (or Deputy), arrange for the appointment of a Government Technical Adviser (GTA). The GTA would go to the OSF and provide advice both to the Government and to those involved in responding to the incident locally. The NHS Board within whose boundary the site is located should be represented at an appropriate senior level (usually including the Director of Public Health) in the OSF to:

J2.7.1 Give advice to the police, site operator, local authorities, GTA and others on health implications and possible health measures, drawing upon necessary technical assistance, monitoring data and assessments from the site operator, NRPB, SEPA and other sources;

J2.7.2 Advise on the implementation and progress of NHSScotland emergency arrangements and their co-ordination with those of others;

J2.7.3 Ensure the provision of information about the incident and its management to the NHS Board Control Centre for transmission to hospitals, general practitioners and other NHSScotland staff who need it and to neighbouring NHS Boards;

J2.7.4 Participate in media briefing at the OSF or its associated Media Briefing Facility (MBF);

J2.7.5 Maintain direct contact with SEHD to ensure full consistency, and synchronisation, of health advice given locally with that nationally by Ministers and the Chief Medical Officer.

J2.8 Where a Local Authority Emergency Centre (LAEC) is established separately as a focal point for local co-ordination, the NHS Board may require to be represented there as well as at the OSF.

J2.9 Formal planning arrangements may not exist for other users of radioactive materials. NHS Boards should make themselves aware of users within their areas, and liaise with them as necessary on emergency arrangements. This is best done in co-operation with local authorities who will normally have been notified.

J3 COUNTER-MEASURES

J3.1 In the context of implementing counter-measures, 3 time phases can be identified: pre-release, emergency and longer term. The pre-release phase starts when a substantial risk of imminent release of radioactive material is identified and ends when either a release occurs or the plant is brought back under control. During this period, precautionary counter-measures may be implemented, to ensure that appropriate protection is in place before a release occurs. The emergency phase lasts from the time a release occurs until shortly (i.e., no more than a day or two) after the plant has been made safe and there is no further imminent threat of release. The longer-term phase follows the emergency phase and continues until no further remedial measures are required. This may be a matter of weeks, months or years. Counter-measures which may be implemented during all 3 phases of an incident are as follows, further information is at Appendix 3:

3.1.1 Sheltering - the public would be advised to stay indoors, close doors and windows and follow advice given by local radio and television stations. Sheltering reduces the risk of exposure to direct radiation and the inhalation of radioactive material;

J3.1.2 Taking stable iodine tablets - to minimize the effects of any uptake of radioactive iodine from the passage of the plume. These tablets work by saturating the thyroid gland with non-radioactive iodine to reduce the uptake of radioactive iodine (it should be noted that radioactive iodine is only likely to be present in an accident involving a nuclear reactor);

J3.1.3 Evacuation - from a downwind sector from the site to reduce the risk of exposure to radioactivity in the plume or deposited on the ground;

J3.1.4 Control of contaminated/potentially contaminated food supplies - in accordance with advice from the Food Standards Agency. Control would be established by Order made under the Food and Environment Protection Act 1985;

J3.1.5 Control of contaminated/potentially contaminated water supplies - in accordance with advice from the Scottish Executive Environment and Rural Affairs Department.

J3.2 In the longer term further measures may need to be implemented including:

J3.2.1 Relocation - the longer-term removal of people away from the contaminated area to avoid the accumulation of high long-term radiation doses from the ground deposition of radionuclides. It may be implemented either following evacuation or as a separate action;

J3.2.2 Decontamination of land and property - following assessment of alternative means of decontamination and of any resultant waste disposal, major civil engineering to immobilise material to prevent, for example, its resuspension in air might be required.

J3.3 The key factor in determining whether, when and how to implement or cease any counter-measure is that it should do more good than harm, especially as regards human health. NHS Boards should thus ensure that they are fully involved in the assessment and decision making process.

J4 ARRANGEMENTS FOR CASUALTIES

Radiation Hazards

J4.1 The principal hazard is the release from safe containment of materials emitting ionising radiation. The amount, type and form of the material would depend on its source and the nature of the incident. For example, radioactive material might be released from a nuclear reactor, from a wide variety of substances in transit or from products in storage or use industrially, in research or health care. Radioactive material released in an incident is likely to be carried by the wind, behaving like a plume of smoke, dispersing into the air and depositing activity on the ground. People may thus incur:

J4.1.1 Exposure to direct radiation from a radioactive plume following a substantial airborne release, or from radionuclides deposited on the ground or in buildings;

J4.1.2 Exposure to radiation from radionuclides contaminating the body surface, clothing or possessions;

J4.1.3 Internal exposure to radiation following inhalation or ingestion of radioactive substances as a result of direct atmospheric or environmental contamination or, subsequently, by radioactive material in water or food.

J4.2 Although incidents involving radioactive materials used in industry, medicine, research, teaching or agriculture will be more limited in their environmental impact, they are likely to occur much more frequently than nuclear site incidents and can have serious health consequences. Plans should anticipate the possibility of contamination, and of radiation injury, to both workers and members of the public

Casualties

J4.3 It is anticipated that non-essential personnel would be evacuated from a nuclear site before any significant release of radiation occurs, thereby limiting the number of casualties. Possible casualties can be considered under 3 headings:-

J4.3.1 Conventional Injury Conventional injuries could arise from events leading to the incident, such as fires or steam leaks; or follow incidents and panic.

J4.3.2 External Exposure People bringing the plant under control or attempting to save life, as well as injured individuals immobilised close to the reactor or plant could receive significant doses of external radiation affecting the whole or parts of their bodies.

J4.3.3 Contamination People may become externally contaminated either by exposure to a radioactive cloud or by contact with contaminated surfaces. In addition, particles from the radioactive cloud could be inhaled or ingested with resultant internal contamination.

J4.4 The casualties require different handling depending on the radiation exposure, however it is an important principle that treatment of life threatening injury should take priority over monitoring or decontamination.

J4.4.1 Physically injured and known not to have received a significant dose of radiation and known not to be contaminated with radioactive material - These patients require no special facilities relating to radiation. They present no hazard to attendants, vehicles and treatment facilities. They will require a full assessment and subsequent medical counselling.

J4.4.2 Exposed to a high radiation dose whether physically injured or not - Treatment should be directed to managing the effects of the received dose. Unless they are also contaminated with radioactive material, they present no hazard to attendants and there is no risk of contamination of vehicles or treatment facilities. However, if they also have physical injuries then this can seriously affect their prognosis and medical management. (See Appendix 4.)

J4.4.3 Contaminated or possibly contaminated whetherphysically injured or not- Contaminated casualties are those who have radioactive material on their skin or clothing or who have inhaled or ingested radioactive material. This material will continue to emit radiation so long as it is active and not removed thus adding to the radiation dose received by the individual if the contamination persists. Transfer of contaminating material to attendants or to the patient's surroundings can cause a small risk of individuals other than the patient receiving a radiation dose. Precautions will be required to reduce the spread of contamination to attendants, vehicles and treatment facilities. Decontamination is required to prevent or reduce further radiation doses, to remove the risk of inhalation or ingestion of contaminating material, or the transfer of such material to others (see Section J5). Patient clothing, dressings, swabs etc. and excreta should be bagged, labelled and retained for analysis.

Action at the Scene of an Incident

J4.5 Contingency plans for major nuclear installations do not envisage ambulance or other NHSScotland staff having to enter an area where they would be exposed to high levels of radiation or to heavy contamination. Similarly, it is extremely improbable that staff attending a nuclear industry or MoD off site incident would be exposed to levels of radiation that would cause a significant health risk. However, there are precautions which should be taken at an incident site and in the handling of possibly contaminated casualties.

J4.6 Monitoring facilities and/or expert advice may be available at the incident site to permit a rapid assessment of any contamination of the casualty. If monitoring facilities are not available, any casualty must be assumed to be externally contaminated and handled accordingly. (Handling casualties with internal radioactive contamination alone normally requires no special protective clothing above what is already familiar to ambulance staff.) Significant external contamination is unlikely to be found outside a major nuclear establishment that would have its own staff to deal with immediate medical treatment and casualty handling. However, in the extremely unlikely event of staff having to deal with casualties who might be significantly externally contaminated or enter an area that is grossly contaminated the main priority will normally be to minimize the risk of internal contamination due to inhalation of airborne radioactive materials. The use of PPE issued to the ambulance service and NHSScotland for protection against radioactive materials will be part of the associated training programme. , Site operators would be responsible for assessing the risk and for issuing any additional or alternative protective clothing. Where possible, advice from an NHS Radiation Protection Adviser should be sought.

J4.7 Precautions should be taken to reduce the spread of possible contamination. Placing a plastic sheet beneath the patient can reduce contamination of the stretcher or the ambulance. Placing a similar sheet over the patient's body can further reduce spread of contamination (in the absence of plastic sheets, ordinary sheets and blankets may be used). On arrival at a hospital they should not remove such sheets until the patient has entered the hospital.

J4.8 Potentially contaminated casualties should not be given either food or drink (unless oral medication is urgently required - this may include stable iodine where appropriate - but in all cases must not prejudice management of the casualty's injuries and must be preceded by local facial decontamination) nor be allowed to smoke until they have been monitored and if necessary decontaminated. Ambulance and other NHSScotland staff who have handled potentially contaminated casualties should take similar precautions.

Transport to Hospital

J4.9 Where the casualty's condition permits, he should be taken to a hospital designated to receive contaminated casualties (see para J4.11 below). Where this would result in unacceptable delay in obtaining treatment for serious or life-threatening injuries, the casualty should be taken to the nearest Accident & Emergency department. In either event, the hospital must be notified before arrival that a casualty who is or may be contaminated with radioactive substances is to be expected so that appropriate arrangements can be made.

J4.10 After the patient has been delivered to the hospital, the ambulance should be parked in a designated area to await monitoring and decontamination. The ambulance crew should remain at the hospital until they can be monitored and, if necessary, decontaminated. Any used protective clothing should be placed in a plastic bag for subsequent monitoring.

Designated Hospitals

J4.11 Each NHS Board should make arrangements for, and designate in its emergency plan, a hospital or hospitals prepared to accept casualties arising within its area who are contaminated with radioactive material. Minimum requirements for such designation are:

• 24-hour Accident and Emergency cover

• ready availability of medical physics facilities capable of measuring the extent and distribution of the contamination;

• appropriate facilities for decontamination.

J4.12 While contaminated casualties should normally be taken to a designated hospital, the physical condition of the casualty or other circumstances might require treatment to be given in any hospital with Accident & Emergency facilities. Thus, it is important that all such hospitals should have contingency arrangements to deal with contaminated casualties. It will usually be possible to seek further advice from a designated hospital before proceeding beyond the initial treatment stage. Nevertheless, staff should be aware of the basic precautions to allow them to treat contaminated casualties without risk to themselves, and of procedures for obtaining expert advice and assistance. A series of suggested management criteria are presented at Appendix 4.

J4.13 Not all hospitals designated to accept casualties contaminated with radioactive material will be able to treat those affected by a high radiation dose. Also, not all casualties exposed to high external radiation doses (for example in incidents involving irradiation facilities and industrial radiography) will have residual contamination with a radioactive substance. Any necessary decontamination, initial monitoring and first aid treatment might be carried out on the premises where the incident occurred, or in a hospital designated to receive casualties contaminated with radioactive material. Casualties exposed to high doses of radiation should then be transferred to a hospital able to provide the necessary specialist treatment and care.

Preparation of Casualty Reception and Treatment Areas

J4.14 The selection of a suitable area for the reception and treatment of suspected contaminated casualties may present considerable difficulty. Ideally, an area which is physically separate from the main area of the Accident & Emergency department and has its own outside entrance or a room(s) within the department which can be closed off should be selected, in order to minimize disruption to normal working during the treatment of the contaminated patient and during any necessary subsequent monitoring and decontamination procedures. Any monitoring and decontamination equipment and other material specifically required for the handling of contaminated casualties should be stored as near to the designated area as is practicable. If no accommodation can be provided with adequate separation from the main Accident & Emergency department, consideration may have to be given to closing or restricting the normal use of the department during the handling of the incident, and diverting routine work elsewhere.

J4.15 The selected area should be equipped to allow resuscitation and emergency treatment, as well as decontamination to be carried out. The need for these facilities might preclude the setting aside of accommodation specifically to cover such a rare event. Other factors which should be considered include:

J4.15.1 Ventilation: the ventilation arrangements should be such as to minimize the risk of contamination from the designated area being transmitted to other parts of the hospital by this means.

J4.15.2 An adequate water supply is essential for decontamination purposes and the drainage system should be such as to allow discharge only of amounts of radioactive materials within the permissible limits for this method of disposal, under the supervision of the Radiation Protection Adviser.

J4.15.3 Adequate means of communication should be available to minimize the necessity for staff to move to and from the potentially contaminated areas.

J4.15.4 Mobile X-ray equipment should be considered to obviate the need to take a possibly contaminated casualty into the main X-ray department.

Measures to Prevent the Spread of Contamination

J4.16 Possible spread of contamination can be minimized by relatively simple measures and this will greatly simplify subsequent monitoring and decontamination procedures. Where time permits, detailed advice from the Radiation Protection Adviser should be obtained.

J4.17 Work surfaces etc. in the designated area can be protected by plastic sheeting, heavy-duty paper, blankets or sheets. Plastic sheeting on floors is not recommended. Similar means can be used to minimize contamination of ambulances, stretchers and trolleys. A plentiful supply of paper towels and tissues should be available.

J4.18 Entry to, and departure from the designated area should be strictly controlled. There should be facilities to allow such staff to change their footwear on leaving the designated area. However, ideally, nothing and no one should leave the area until monitoring and decontamination has been carried out to an acceptable level.

J4.19 Decontamination of the patient (see Appendix 4) should be carried out in the controlled area where this is compatible with the patient's need for treatment. However, the urgent treatment of injuries takes precedence over decontamination. If the patient needs to be transferred to the operating theatre or intensive care unit before decontamination can be completed, the main consideration should be the possibility of removal of clothing, where most of the radioactive contaminant is likely to reside. If transfer for treatment prior to full decontamination becomes necessary, the possible spread of contamination may be reduced by covering appropriate areas with plastic sheeting or other impervious material. If the patient does have to be transferred, this must be done by staff other than those who have been working in the controlled area.

J4.20 All material which might have become contaminated such as patients' clothing, dressings, items of equipment, staff protective clothing and fluid used for washing, if beyond safe discharge levels (see J4.15.2), should be retained within the area in suitable containers. Such containers, appropriately labelled, must not be disposed of except under the instructions of the Radiation Protection Adviser. Urgent laboratory specimens may be sent to the laboratory but the outside of containers should be swabbed to remove any contamination and the specimens labelled to indicate to laboratory staff the need for caution in handling and disposal.

J4.21 Any area in which a contaminated person has been handled must be monitored and, if necessary, decontaminated before it can be used for any other purpose.

Disposal of Bodies

J4.22 Conventional cleansing of the body, with suitable precautions to prevent contamination of the attendant or the surroundings will usually reduce external contamination to an acceptable level. However, bodies contaminated by radioactive material must not be released for burial or cremation until radiation protection advice has been obtained on the proposed method of disposal. Until such a decision is reached, the spread of contamination can be prevented by enclosing the body in a heavy-duty plastic body-bag. In the case of certain radionuclides it may also be necessary to store the body in an area away from places to which members of staff and the public have access.

Protection of Staff

J4.23 Suitable protective clothing should be made available for all staff engaged in the handling and treatment of contaminated patients. Overalls, rubber gloves and boots (e.g., operating theatre clothing) are likely to be adequate to deal with the majority of situations. However, in handling patients whose skin, hair or clothes might be with significantly contaminated by radioactive materials, the need for respiratory protection should be considered. Waterproof aprons should be worn by those staff who are expected to wash skin or wash out wounds etc.

J4.24 Careful handling procedures will minimize contamination of staff, the area and equipment. Any staff members who have handled contaminated patients or materials should be monitored and, if necessary, decontaminated before leaving the designated area. Staff must be warned not to eat, drink or smoke until monitoring and decontamination has been carried out.

Training

J4.25 All Accident & Emergency staff should have sufficient knowledge of radiation protection to reduce, as far as practicable, hazards to the patient, to colleagues and themselves and to limit contamination of premises and equipment. Practical skills, including contamination monitoring and decontamination should be maintained through regular exercises of procedures.

J5 MONITORING AND DECONTAMINATION

J5.1 Monitoring and any necessary decontamination of workers, casualties and others, including members of the rescue services, at a major nuclear site would normally be carried out by the operator's staff, the SAS and the fire brigades. Further monitoring, and where necessary decontamination, of casualties taken to hospital should be undertaken there as described in Appendix 4.

J5.2 There will also be a need to monitor all other people who may be contaminated, or who think they may be contaminated, as a result of the incident. NHS Boards should take the lead in co-ordinating off-site monitoring of people.

Planning a Monitoring Strategy

J5.3 The very wide range of potential incidents involving the release of radioactive material is reflected in the correspondingly wide range of responses required. As a general principle, plans should give detailed guidance on how to carry out monitoring following the largest incident that can reasonably be foreseen; they should, however, also allow the response to be flexible, and should enable the response to be extended to deal with much larger (but much less probable) incidents, or demand from large numbers of members of the public for monitoring.

J5.4 In developing plans for personal monitoring, the underlying principles should be to enable measures that would significantly reduce doses to individuals to be carried out promptly, to ensure that scarce staff, equipment and other resources (e.g., showering facilities at a reception centre) are used effectively, and to keep members of the public who have been monitored fully informed. The administrative tasks of running a monitoring programme should not be underestimated.

J5.5 Priority should normally be given to monitoring for external contamination (i.e., activity deposited on the skin, hair or clothing). This involves the use of hand-held equipment and might indicate a need for decontamination measures such as washing exposed skin which can result in significant dose reductions. Monitoring for internal contamination (normally resulting from inhalation or ingestion of contaminated material) requires more specialist equipment and is for dose assessment rather than decontamination.

J5.6 In order of importance, the objectives of a radiation monitoring programme for members of the public following a major radiation incident are:

J5.6.1 To identify those who are externally contaminated at a level which requires urgent decontamination to avoid illness.

J5.6.2 To reassure those who are not so contaminated.

J5.6.3 To identify those who are externally contaminated at lower levels but for whom decontamination is still justified.

J5.6.4 Where radioactive iodine is involved, to inform assessments of thyroid uptake and radiation dose.

J5.6.5 To prioritise subjects for assessment of uptake of other radionuclides and resulting radiation dose.

J5.6.6 To provide information to individuals on their internal radiation dose, with the aim of providing reassurance where appropriate.

J5.6.7 To supply information on radiation doses received by members of the public for incident assessment purposes.

J5.7 Monitoring of people affected by emergency counter-measures (evacuation, sheltering, distribution of stable iodine) should be given a higher priority than monitoring other groups within the general population.

J5.8 The public's perception of risk from radiation, and their reaction to a radiation incident, will play a considerable part in determining the demand for personal monitoring.

J5.9 Within the term monitoring it is useful to distinguish screening, where an action level is set to decide between alternative courses of action; and measurement, where numerical values are recorded for the purpose of dose assessment. Several distinct phases of a monitoring programme can be identified:

J5.9.1 Early screening of possibly large numbers of people for external contamination;

J5.9.2 Subsequent screening of essentially the same group of people for internal contamination;

J5.9.3 At a later stage, more accurate measurement of radio-iodine thyroid uptake and/or assessment of uptake of other radionuclides using whole body monitor facilities with the aim of assessing internal radiation dose;

J5.9.4 Long-term follow-up studies to assess doses received by the general population in the affected area.

J5.10 If persons being monitored are externally contaminated, then avoidance of contamination of the monitoring area is essential. Measures should be put in place to monitor and control the spread of contamination as far as possible.

J5.11 All staff should be given training, or should have sufficient experience to be able to take on their allocated role.

J5.12 To illustrate the issues that need to be considered when planning a monitoring programme, guidance is given at Appendix 5 for 2 incident scenarios that would be among the largest that could reasonably be foreseen. The first scenario is a nuclear power reactor accident resulting in release of fission products, which requires monitoring for several hundred people. The second is a nuclear weapons accident (non-nuclear explosion or fire) resulting in localised dispersal of airborne plutonium oxide, also requiring monitoring for several hundred people. The first scenario is discussed in detail, the second only briefly.

J5.13 The guidance given for these scenarios is addressed primarily to NHS Boards within whose area the incident occurs. NHS Boards more distant from the site of an incident, whether within or outside the UK, may also need to implement a monitoring programme. Away from the immediate vicinity of the incident significant levels of external or internal contamination of people are unlikely to occur, and so simplified plans based on the guidance given in Appendix 5 could be developed. Nevertheless, there may well be demands for monitoring from very large numbers of people.

The Radiation Monitoring Unit (RMU)

J5.14 NHS Boards may need to establish a temporary RMU to carry out the first two phases of monitoring listed in paragraph J5.9. This Unit would primarily be intended for monitoring evacuees. The later phases of monitoring are likely to be conducted at hospitals with medical physics departments (although other facilities are likely to be available, and their use should be considered). The establishment and operation of a RMU are discussed at Appendix 5.

Decontamination at the scene of an incident.

J 5.15 Arrangements for decontamination of casualties contaminated with chemical, biological or radiological materials at the scene of an incident are defined in a joint emergency services' guidance document " Guidance for the emergency services on decontamination of people exposed to hazardous chemical, biological or radioactive substances".

APPENDIX 1 TO ANNEX J

ARRANGEMENTS FOR PARTICULAR CONTINGENCIES

1J.1 OVERSEAS REACTOR INCIDENT

An incident involving a nuclear reactor overseas can lead to contamination of the environment within the UK (e.g. Chernobyl 1986). People and goods close to the scene may subsequently enter the UK.

1J.2 UK CIVIL NUCLEAR REACTOR SITES

Civil Reactors are operated in Scotland at Hunterston B, Torness (British Energy) and Chapelcross (BNFL). Hunterston A (BNFL) and AEA Technology's reactors at Dounreay are being decommissioned. The most Northerly of reactors in England are at Sellafield in Cumbria and Hartlepool.

1J.3 MILITARY NUCLEAR REACTOR INCIDENT

Nuclear powered warships are based at the Clyde Submarine Base (including HMS Neptune, Faslane, and the RN Armament Depot Coulport). A number of berths elsewhere in Scottish waters are designated for their use and dockyard facilities at Rosyth are used to refit nuclear submarines and to berth decommissioned vessels. The MOD's VULCAN test reactor is operated at Dounreay.

1J.4 NUCLEAR FUEL/WASTE IN TRANSIT (CIVIL OR MILITARY)

Nuclear fuel and associated radioactive waste is transported in secure protective containers between reactor sites and reprocessing/storage facilities by road, rail, sea or air.

1J.5 NUCLEAR WEAPON TRANSPORT INCIDENT

The dominant radioactive hazard involved in an incident in which both a nuclear weapon casing and its transport container were breached is alpha radiation from plutonium. All nuclear weapons movements, by road, air or sea, are conducted by specially trained personnel.

1J.6 SATELLITE WITH NUCLEAR POWER OR MATERIAL RETURNING TO EARTH

Should a satellite containing nuclear material, through malfunction or other cause, leave its orbit it might re-enter the earth's atmosphere. While most will burn up and pose no hazard; some will reach the surface substantially intact, while others will break up scattering pieces widely. Such incidents are almost always predictable in terms of timing and broad geographical area of impact, but less so as to the damage they might bring.

1J.7 INCIDENT ARISING FROM INDUSTRIAL/AGRICULTURAL/SCIENTIFIC/

EDUCATIONAL/MEDICAL USE OF RADIOACTIVE MATERIAL

Under Health and Safety at Work legislation employers have a responsibility for protecting their employees and other people from any harmful effects of their work activities. In particular, Regulation 7(1) of the Ionising Radiation Regulations 1999 requires employers to assess the potential hazard of their use of radioactive material.

1J.8 NATIONAL ARRANGEMENTS FOR INCIDENTS INVOLVING RADIOACTIVITY (NAIR)

1J.8.1 The NAIR scheme is co-ordinated by NRPB to provide specialist advice where plans do not exist for specific events. Details of the scheme are available on the NRPB website at ( http://www.nrpb.org/radiation_incidents/nair.htm) and from the NAIR Handbook (http://www.nrpb.org/radiation_incidents/nair_2000.pdf). Its function is to make available, to the police and other emergency services, advice on safety measures required at incidents involving, or thought to involve, radioactive substances. The scheme provides for assistance in 2 stages. The first stage enables an experienced person to advise the police whether a potential hazard from radioactivity exists, and if it does, on the action necessary to minimize and contain any danger. The second stage provides for more sophisticated resources should they be necessary. Each police force has been allocated first and second stage assistance centres. These are contacted by calling 0800 834 153 which connects the caller to the Atomic Energy Agency constabulary who will then co-ordinate communication with the appropriate assistance centres and will inform SEPA. Several first stage assistance centres are NHS medical physics departments; second stage centres are invariably major nuclear establishments.

1J8.2 The arrangements are intended to cover incidents in public places (e.g., damage to containers, discovery of suspected radioactive substances) and incidents involving the public in premises where radioactive materials are not normally handled. NAIR is not intended to cover incidents in premises where radioactive substances are normally handled because in these cases staff should be available who are competent to deal with the problem. Nor are NAIR arrangements intended to cover on or off site incidents at civil nuclear installations, MoD establishments, or transport accidents involving nuclear fuel or weapon components as described at paragraphs 1J.2-1J.5 above. (For offsite transport, the RADSAFE provisions referred to in 1J.4 apply but the contact number is the same as that for NAIR). However, should the police consider that a danger to the public exists and if planned expert assistance is not immediately available, they may seek assistance via the NAIR arrangements. The NAIR arrangements are quite separate from NHS contingency plans. Specifically, the designation of hospitals prepared to accept contaminated or irradiated casualties is a matter for NHS Boards. Lists of such hospitals are held by NRPB for the purposes of NAIR response. NAIR does not cover arrangements for dealing with casualties or with arrangements for monitoring casualties or the public following an accident.

1J8.3 Since NAIR is founded upon the use of individual specialists drawn from their normal duties as required, NHSScotland medical physics staff, and in particular Radiation Protection Advisers, may be participants in NAIR. Staff called out under the NAIR arrangements are working on normal NHSScotland duties, and thus subject to the provisions of the NHSScotland Superannuation and Injury Benefits Schemes as well as the Industrial Injuries Scheme.

APPENDIX 2 TO ANNEX J

EMERGENCY REFERENCE LEVELS/INTERVENTION LEVELS

2J.1 The NRPB's published principles for intervention after a nuclear accident require the implementation of counter-measures which aim to do more good than harm, taking account of all likely consequences. The quantitative criteria recommended by NRPB for the introduction of counter-measures to protect the public are known as Emergency Reference Levels (ERLs).

2J.2 ERLs are expressed in terms of radiation dose to an individual that could be averted if the counter-measure is taken. For each counter-measure a lower and upper ERL is set. The lower ERL is the smallest reduction in dose likely to offset the disadvantages introduced by the counter-measure: it should be regarded as the threshold for considering implementation of the counter-measure. The upper ERL is the reduction in dose for which the counter-measure would be justified in nearly all situations, and above which strenuous efforts should be made to implement it.

2J.3 ERLs recommended by NRPB are:

2J.4 ERLs cannot of course be compared directly with measurements in the field, or with the results of measuring samples of materials from the environment. It is necessary therefore for "trigger" or site specific intervention levels, expressed in the same quantities as measurements are expressed, to be calculated for each site and for each possible counter-measure. Trigger levels should be explicitly included in local plans and be compatible with ERLs.

APPENDIX 3 TO ANNEX J

COUNTER-MEASURES

Sheltering

3J.1 In this context sheltering refers to staying indoors, with doors and windows closed and ventilation systems turned off. It provides protection from external irradiation from radioactive material in the air and that deposited on the ground, and from inhalation of radioactive material. Typical dose reductions for solidly built and reasonably airtight UK housing are a factor of 10 for external exposure and a factor of 3 for inhalation of particulates. However, the dose reduction for inhalation of vapours (e.g., elemental radioiodine) is negligible, and the protection against external irradiation afforded by light constructions, such as caravans, is very small. The level of protection afforded will not, in general, be significantly affected by occasional opening and closing of outside doors, or short trips out of doors for essential activities.

3J.2 If a release to atmosphere occurs, there are 4 main situations for which sheltering is likely to be the optimum counter-measure:

• a release consisting mainly of radioisotopes of noble gases (to reduce the external dose);

• a release which would result in relatively low doses;

• a release which would result in very large short-term doses, for which evacuation could not be carried out in advance of the release;

• circumstances in which evacuation either is not possible or would entail considerable risk to the evacuees.

3J.3 Where radioiodine is known to form a significant part of the release, the administration of stable iodine (to reduce the dose to the thyroid from inhalation of radioiodine) in conjunction with sheltering (to reduce the amount of radioactive materials inhaled and the external irradiation dose) can form a very effective counter-measures strategy. However, it is important not to overlook the inhalation dose likely to be received from other radionuclides. It must also be remembered that the benefit of sheltering is strongly dependent on the type of buildings available to accommodate people and the available means of communicating the advice to shelter and cease sheltering. It is therefore important to take these factors into account when formulating emergency plans for specific sites.

Evacuation

3J.4 In this context, evacuation is defined as the removal of people from an area in order to avoid (or potentially to avoid) relatively high short-term exposures. The primary purpose of evacuation is to protect the population against the inhalation of radionuclides and external exposure from radionuclides in the air and deposited on the ground. It is distinct from relocation, which is the removal of people from the contaminated area for periods of weeks, months or years to avoid chronic, long-term exposures, although relocation may be carried out as an extension to evacuation.

3J.5 Evacuation is the only counter-measure which has the potential to prevent virtually all exposure to a release. However, this is only achieved if the evacuation is carried out before the release occurs. In other situations partial dose savings will usually be achieved, although it is possible that evacuation may result in higher doses than alternative counter-measures or than no counter-measures, if it is incorrectly implemented. While people are in transit, their protection against external irradiation and inhalation of radionuclides is likely to be very much less than the protection they would receive from remaining inside solidly constructed buildings. It is therefore not advisable to evacuate people through areas where radionuclide concentrations in air are relatively high, unless it is judged that the dose which they would receive if any other counter-measures strategy were implemented (including taking no counter-measures) would be higher than the dose received during the evacuation.

3J.6 Evacuation can be effective for reducing doses following many different types of accidental release. It can be effective in situations involving an accidental release to atmosphere, or localised contamination of the environment following, for example, the breakage of a radiography source or the crash of a nuclear-powered satellite. Five main situations can be identified in which evacuation is likely to be the optimum early counter-measure:

• precautionary evacuation, in response to the threat of a probable release;

• in response to a large release of predictable duration or size, particularly one for which there is sufficient advance warning for people to be moved before it begins;

• in response to an accident for which the release to atmosphere may be prolonged, and the size of a release is very uncertain and potentially large;

• after the cessation of a release to atmosphere, to avoid doses from short-lived radionuclides deposited on the ground;

• after the cessation of any release, to avoid external exposure while localised, short-term decontamination is carried out.

3J.7 As with sheltering, where radioiodine is known to form a significant part of the release, the administration of stable iodine in conjunction with evacuation can form a very effective counter-measures strategy. However, it should be noted that it is not necessary to administer stable iodine if precautionary evacuation has been carried out, or the evacuation was achieved very quickly after the start of the release.

Administration of Stable Iodine Tablets

3J.8 Where material escaping after an incident at a nuclear installation contains radioactive iodine this may be inhaled, or ingested via contaminated food or water. This will give a radiation dose, in particular to the thyroid which concentrates and stores any form of iodine. A radiation dose from ingestion can be averted or minimized by restrictions in the supply of food - most likely milk and milk products. Uptake of inhaled radioactive iodine to the thyroid can be blocked by the administration of stable (i.e., non-radioactive) iodine. Whilst most effective if given shortly before or immediately after exposure, stable iodine will still block uptake of radioactive iodine to a useful extent up to some hours after exposure.

3J.9 Planning Requirement Emergency plans drawn up to deal with incidents at major nuclear sites should include detailed arrangements for the supply, storage, authorisation to issue and rapid distribution of stable iodine tablets to staff on the site, to responding emergency services personnel and to members of the public in the DEPZ. Plans should also address, in outline, how those detailed arrangements might be extended beyond the DEPZ in the unlikely event that distribution might be required there. While it is also unlikely that incidents other than those involving a major nuclear reactor site will require this counter-measure, outline arrangements to secure tablet supplies and effect distribution should be developed by all NHS Boards.

3J.10 Planning Responsibility Responsibility for taking the lead on planning the distribution of stable iodine tablets to the public rests with lead HNS Boards, as defined at paragraph J1.3. Development and maintenance of effective plans will require Boards to secure the active co-operation of the site operator, local authority, emergency services and other agencies which might be able to make people available to assist in the task.

3J.11 Authority to Issue Tablets should only be issued to the public on the authority of the Director of Public Health. To ensure that tablets can be issued without delay when required, Directors of Public Health should give prior authorisation for the commencement of issue in the event of specific, pre-determined conditions. Precise parameters should be set for this including "trigger" measurements derived from application of NRPB's Emergency Reference Levels to site specific modelling, predicting the nature, extent, direction and mobility of any release.

3J.12 Stocks of Tablets Bulk stocks of tablets are required to be provided and maintained by site operators. To facilitate rapid distribution when required, some of this stock might be pre-positioned in reception centres, schools, health centres, emergency services' stations or other premises with appropriate and secure storage facilities. In such cases the quantity of tablets held in each place should be detailed, together with responsibilities for their custody, periodic inspection and issue.

3J.13 Distribution Planning Detailed plans should be drawn up for the rapid distribution of stable iodine tablets to all people within the DEPZ. The effectiveness of the tablets for thyroid blocking depends on administration shortly before, or as soon as possible following, exposure to radioiodine. 60-70% blocking can be obtained at 3 hours, but 50% of radioactive iodine uptake will still occur at 5_ hours. As indicated in paragraph 3J.3 above, the combination of sheltering with the administration of stable iodine is important. Immediate sheltering followed by stable iodine at 3 hours can avert up to 95% of the dose to the thyroid, even after 6 hours sheltering the taking of stable iodine can avert up to 90%.

3J.14 Pre-Distribution Pre-distribution of stable iodine tablets to less accessible households or communities may have to be considered if detailed local feasibility appraisal concludes that no means can be found to effect distribution to them at the time sheltering was implemented. Before approval to pre-distribution is given, Scottish Executive Health Department should be consulted. [DN. Do we want to retain this?] A report should be submitted stating in clear terms the nature of the problem, attempts made and with whom to overcome it, and details of arrangements for the safe storage and keeping in date of pre-distributed tablets.

3J.15 Issue Those who may be available to assist in the issue of stable iodine tablets include people employed by the site operator, emergency services and local authority, as well as NHSScotland staff. Sufficient manpower should be earmarked not only to issue tablets at reception centres, but also in circumstances where evacuation is not implemented and the population is advised to shelter. Those issuing tablets to the public and acting under the authority of the Director of Public Health will be indemnified by Scottish Ministers against legal liability arising from the issue of tablets.

3J.16 Advice to the Public When tablets are issued they must be accompanied by clear instructions on their use, on contra-indications and on any necessary follow-up. To facilitate this, leaflets have been printed and are stored with bulk stocks of the tablets. In the event of an incident in which there was no requirement for the issue of stable iodine, arrangements should be made for the public to be told that the risk from exposure to radioactive iodine had been assessed as being low and therefore tablets will not be issued.

Food Counter-measures

3J.17 The ingestion of contaminated food following an accident can be reduced by a wide range of controls and remedial actions, including measures introduced at the farm, the use of food processing and preparation, and controls or restrictions on the sale or distribution of foods. Controls may also be placed on the use of contaminated animal feeds. The most extreme, but often the simplest measure, particularly where food supplies are plentiful, is the banning of all food contaminated above a specified level. In any consideration of such measures NHS Boards should collaborate with representatives of the Scottish Executive Environment and Rural Affairs Department and the Food Standards Agency

3J.18 Regulations have been issued by the Council of the European Union specifying intervention levels (here termed CFILs) for radioactive contamination in marketed foods and animal feeds. The levels specified for foods are consistent with the latest advice from the International Commission on Radiological Protection (ICRP). If restrictions were imposed on food at the levels of the CFILs, then the doses received by most individuals in the UK would be very small. Estimates of the upper levels of dose that would be received are, at most, similar to those from natural radiation exposure. The Council Regulations do not provide intervention levels for drinking water supplies. NRPB recommends UK Action Levels for drinking water that are equal to the CFILs specified for liquid foods. The CFILs and NRPB's Action Levels for drinking water supplies are listed in the tables below:

Council Food Intervention Levels in Major Foods (Bq/Kg)*

* These levels are associated with specific exclusions and restrictions, as detailed in the Council Regulations.

UK Action Levels for Drinking Water Supplies

APPENDIX 4 TO ANNEX J

CASUALTY RECEPTION AND TREATMENT

4J.1 All persons involved in a radiation accident should be carefully interviewed; a full, detailed description of the radiation situation should be made as soon as possible. For purposes of dose assessment it is often useful, by means of a diagram, to show the position of each person present at the accident site.

4J.2 The first priority is the treatment of life-threatening injuries (shock, bleeding, thermal burns, fractures etc.) by whichever type of specialist is appropriate for the condition.

4J.3 The second priority is the assessment of the extent and magnitude of contamination, and decontamination as necessary. Any person with external contamination should be specially and separately treated. The most effective decontamination procedure is washing, subject to control by monitoring. (See Appendix 5).

4J.4 The third priority is that if there is suspected internal contamination, a quick assessment of its nature and degree should be made so that appropriate measures to reduce internal contamination may be started as soon as possible.

4J.5 Suggested Management Criteria

+ Stable iodine should be administered to casualties who have potentially been exposed to radioactive iodine; if the casualty's condition precludes administration specialist advice should be sought.

4J.6 Laboratory Samples The following samples should be collected from patients who may have incurred internal radiation. All biological samples should be retained for subsequent analysis.

A. Blood, approximately 20-30ml for the following analyses:

1. Full blood count

2. Cytogenetic analysis (24 hrs after exposure is optimum time)

3. Biochemical analysis (serum amylase)

4. Analysis for radionuclide content

B. High Nasal (bilateral) and throat swabs - dry swabs stored in labelled holders without transport medium. Should be taken as early as possible and the time recorded. Will need to be sent to laboratory specialising in the measurement of radionuclides.

C. Urine:

1. Routine analysis

2. Biochemical (creatinuria)

3. Analysis for radionuclide content

D. Stools (for estimation of radionuclide contents).

4J.7 The following initial decontamination procedures should be followed:

• Experience has shown that washing with water will effectively remove contaminated material from the skin in most cases. Initial treatment and any necessary washing to remove as much of the suspected contamination as practicable should be done in the controlled area.

• Open wounds should be irrigated and the irrigate saved and labelled. Special care needs to be taken to prevent the spread of possible contamination to other parts of the body and in the cleaning of areas near the eyes and mouth.

• It is inadvisable to excise wounds unless contamination is obvious, or unless surgically indicated, before monitoring assistance is available.

APPENDIX 5 TO ANNEX J

RADIATION MONITORING FOR MEMBERS OF THE PUBLIC

ESTABLISHING A RADIATION MONITORING UNIT

5J.1 The RMU should, where possible, be located at, or adjacent to, a reception centre established by the local authority and specified in the site Emergency Plan. However, suitable NHS or other premises nearby may need to be utilised. Police and the local authority should be consulted when selecting a site. Premises with the following facilities will be required:

• A segregated area where potentially contaminated people can await monitoring. Direct access from outside is desirable; control is needed to prevent their mixing with people known to be free of external contamination.

• An area adjacent to it for external contamination monitoring.

• An area immediately adjacent to that which can be used for decontamination of people. It should have running hot and cold water for washing and, if possible, showering facilities.

• A separate area adjacent to the external monitoring area where internal contamination monitoring can take place.

• Storage for spare outdoor clothing and shoes.

• Storage, well separated from other areas, for contaminated clothing and other contaminated material which may include valuables such as personal jewellery.

• A reporting/recording area with telephone and fax.

• An area, well separated from the monitoring areas, reserved for counselling concerned individuals.

• Separate exit.

It is advisable to develop layout plans for the RMU in advance.

Those attending the RMU should be given a leaflet describing what will happen to them and why. The leaflet should instruct people to minimize movement within the waiting area; this will reduce the possibility of cross-contamination.

Suggested Operational Protocol for the RMU

5J.2 The responsibility for operation of the RMU will lie with the most senior Medical Physicist present.

Staffing

5J.3 Typical staffing might be:

• Medical Physicist in charge

• Medical Physicist/Technicians (or similar grade staff from other organisations)

• Nurses

• Clerks

Arrangements exist in some areas for the nuclear site operator to provide additional staff capable of carrying out monitoring measurements. NRPB may also be able to provide staff to assist with monitoring.

Equipment

5J.4 The following monitoring equipment is suggested:

• contamination monitors e.g., Mini Instruments EP15, Nuclear Enterprises BP4, Berthold LB1210B;

• iodine-in-thyroid monitors e.g., Mini 44A or 44B with ratemeter;

• check sources.

In addition, spare instruments of each type in use should be available. A suggested list of other specialised equipment is at the end of this Appendix.

Preparation of the Unit

5J.5 It is suggested that the following steps should be taken to prepare the area:

• Clear all unnecessary furniture if time allows.

• Identify the areas to be used for the purposes specified in 5J.1 taking due account of the needs of individual dignity/modesty. If necessary, use partition screens and tape barriers to create separate areas.

• Arrange the waiting area in a way that discourages unnecessary movement, perhaps by setting up a queue using tape barriers. Chairs may be provided but must be covered with polythene sheet, to be removed when the person leaves the waiting area.

• Place "tacky mats" (disposable mats with an adhesive surface that removes contamination from the soles of shoes) at all entrances and exists to the area.

• Cover heavily used areas of the floor throughout the RMU (e.g., doorways) with e.g., heavy-duty paper. The floor area between the monitoring area and the decontamination area must be covered. Tape all joins.

• Fix signs at the entry and exit to the RMU prohibiting entry to unauthorised persons.

• Provide protective clothing for the staff.

• Each staff member should ensure that they have been provided with the necessary equipment and supplies to carry out the task to which they are allocated.

Operational Protocol for a Nuclear Power Reactor Incident

5J.6 The operational protocol suggested for a nuclear power reactor incident resulting in release of fission products is summarised in the following flow diagram. It illustrates the decisions to be made and the sequence of events for each person entering the RMU. A discussion of 'action levels' and the various stages in the process follows.

Action Levels

5J.7 Appropriate action levels would be recommended at the time of the accident by NRPB, taking account of the specific circumstances of the accident, and in particular the radionuclide composition of the release. Illustrative values for action levels are given below for planning purposes only.

5J.8 Action Level A should be set so as to identify levels of contamination that could cause deterministic effects on skin (radiation burns), or that could result in committed effective doses of the order of 10 mSv if the activity is ingested. In most cases, the latter criterion is more restrictive than the former, and satisfying it therefore leaves a margin of safety for the avoidance of deterministic effects. Ingestion dose coefficients are generally higher for children than for adults, and so the former must be used when setting the Action Level. If it is assumed that activity distributed over an area of skin of 10cm ² might be ingested before the contamination is removed by normal processes, then the intake criterion corresponds to an activity concentration of the order of 10 ⁴ Bq cm ^-2 for a typical b -emitter such as ¹³¹I. The localised skin dose rate from contamination of 10 ⁴ Bq cm ^-2 over an area of 10cm ² would be of the order of 10 mSv h ^-1. The corresponding reading on an EP15 contamination monitor would be about 100 counts per second at a distance of 30cm from the contaminated area. (Note: full scale on the EP15 is 600 counts per second).

5J.9 Action Level B should be set so as to identify those who are externally contaminated at lower levels, but for whom immediate decontamination at the Unit is still justified. The action level should be based on prioritising the use of the available decontamination facilities to benefit those in most need, and on the general ALARA principle of taking simple steps to minimize doses. It is not a boundary between high and low risk. In setting it, account would need to be taken of the available resources and numbers requiring monitoring. For example, an action level of 300 counts per second at a distance of 1cm from the contaminated area measured using an EP15 monitor would correspond to an activity of about 1000 Bq distributed over an area of 10cm ². This could give rise to an ingestion dose to a child of the order of 0.1 mSv for a typical b -emitter such as ¹³¹I, or a localised dose rate to the skin of the order of 0.1 mSv/hour.

Stage 1

5J.10 People arriving at the facility should be rapidly screened to identify those in need of urgent decontamination. (If the person is identified as someone who has earlier been asked to evacuate or shelter or who has been offered stable iodine, then that person should be given priority for the rapid screening measurement and for subsequent monitoring measurements.) This is the first priority of the facility because the actions to be taken will reduce the risk of injury, even though it is extremely unlikely that such levels of contamination would occur. It is important to identify and treat such people as quickly as possible so as to maximise the dose reduction (they should not be kept waiting while others are monitored), and also to reduce the potential for them to contaminate other people and the facility. If Action Level A is exceeded, the person should be sent immediately for decontamination. A measurement should then be made of the amount and location of any surface contamination remaining. All persons who exceed Action Level A on the first measurement must be sent directly to a hospital designated to receive contaminated casualties.

5J.11 Persons found to be below Action Level A should proceed to the second stage of external contamination screening (waiting in a segregated part of the reception area if necessary).

5J.12 The tasks of Stage 1 could be carried out by one medical physicist, one nurse and 2 clerks. A throughput of about 100 per hour should be possible (although additional clerks would be needed to achieve this). If levels of contamination above Action Level A are encountered, then additional nursing staff would be required to carry out decontamination procedures.

Stage 2

5J.13 Here, more detailed contamination monitoring would be carried out. Persons found to be above Action Level B should proceed to the decontamination area. Measurements above this action level should be recorded, those below it only if time permits. Following decontamination, the person should return for a second screening measurement. One further pass through the decontamination procedures may be advised, but the person should then pass on to Stage 3. Persons below Action Level B could be advised to shower and change as soon as convenient on their return home if this is considered necessary.

5J.14 Persons remaining between Action Levels A and B after decontamination could have a wide range of levels of external contamination. Action Level B would be set on the assumption that activity on the skin would be removed within a few days by normal processes. Consideration should therefore be given to carrying out follow-up measurements after a few days have elapsed.

5J.15 The tasks of Stage 2 could be carried out by teams consisting of one medical physicist, one clerk to record measurements, and one nurse working in the decontamination area. A team would have a throughput of about 20 per hour (assuming most do not need decontamination). To deal with 300 people, at least 3 such teams would therefore be advisable.

Stage 3

5J.16 It is possible that internal contamination may be found in circumstances where no external contamination is present (e.g., the person may already have washed and changed clothes; intake may have been by ingestion, etc.). If the accident resulted in release of radioiodine then measurements of iodine-in-thyroid using hand-held detectors would be the most useful screening method. For other accidents involving fission products, similar measurements of, for example, the chest or abdomen may be feasible, depending on the circumstances of the release.

5J.17 Monitoring results should be used to prioritise people for more accurate uptake measurements, probably comprising iodine-in-thyroid measurements and whole body measurements of other fission products. This prioritisation could include the use of an exemption level below which no further measurements are required. All screening measurements should be recorded, as it may be feasible to use them to provide dose estimates.

5J.18 Body monitoring facilities for uptake assessments could be provided by some medical physics departments. NRPB may be able to provide additional facilities, including a mobile body monitoring system. Some nuclear industry site operators may also be able to provide assistance.

5J.19 The tasks of stage 3 could be carried out by teams consisting of one medical physicist and one clerk to record measurements. A team would have a throughput of about 50 per hour.

5J.20 Internal contamination monitoring has a lower priority than external contamination monitoring. Resources may need to be fully utilised in order to complete the latter within a reasonable time, and in such circumstances it would be acceptable to delay internal monitoring. For instance, individuals who have passed through the external contamination resources for internal contamination monitoring become available.

Stage 4

5J.21 Arrangements should be made for recording the monitoring results of each person passing through the Unit. Monitoring will fall into 2 categories:

a. internal contamination;

b. external contamination.

Examples of report forms are at the end of this Appendix.

5J.22 NHSScotland Medical Physics Departments that wish to submit internal monitoring data to the RIMNET Central Database Facility (CDF) need to be Approved RIMNET Data Suppliers. This status can be achieved via a number of routes. One of these is through the Department of Health which will accredit hospitals that meet specific criteria already demonstrated under the Medicines (Administration of Radioactive Substances) Regulations 1995. This route, unlike others, will not incur cost. Hospitals participating in this scheme will send data to NRPB, in its capacity as co-ordinator of monitoring information.

5J.23 The same departments will be invited to submit summaries of external monitoring data to NRPB. These will not be entered onto the RIMNET CDF, but will give valuable information in the context of population exposure. Details of this scheme, including the accreditation process and precise data formats, will be given under a separate notification.

5J.24 Results of monitoring should also be reported to the individuals monitored. Any doses assessed should be reported, but information given will need to be put into the context of implications for health. This could be achieved by providing a report form, prepared in advance, for the various categories defined in the screening process. An example of such a report form is attached. Trained staff should be available for counselling concerned individuals.

Control of Contamination in the Radiation Monitoring Unit

5J.25 If external contamination is found on persons being monitored, then a member of staff should be allocated to the task of monitoring and controlling contamination of the RMU. Heavily used areas should be regularly monitored, with particular attention paid to tacky mats, floors and seating. Tacky mats and polythene covers should be replaced regularly. Thyroid monitoring probes should be sealed in polythene bags when in use. Checks on background count rates for all of the monitoring instruments in use should be made frequently. Monitoring and decontamination staff should use protective, disposable clothing, and should avoid direct contact with persons being monitored. The Physicist in Charge should be kept informed.

5J.26 Conversely, if external contamination is not found, then contamination control measures should be relaxed as soon as possible in order to minimize unnecessary alarm in members of the public.

Staff Duties

5J.27 Reception/Waiting Area Team

(a) Medical Physicist

• Carry out rapid screening for external contamination on people as soon as possible after they arrive at the Unit, as discussed in paragraphs 5J.10-15. The screening measurement could be made on people queuing in the waiting area, or at the entrance to the Unit provided this does not cause queues to build up outside the Unit. Using an EP15 or similar instrument, rapidly scan (in about 20 seconds) the body at a distance of about 30cm, concentrating on head, hands, elbows, feet, buttocks. If Action Level A is exceeded, then send the person immediately to the decontamination area, first removing and bagging shoes if they are contaminated; overshoes should be provided.

(b) Clerks

• Give appropriate directions to people at the entrance to the Unit. Fill in parts 1 to 9 of the Report form for each person. If the person is identified from the answer to part 2 as someone who has earlier been asked to evacuate or shelter, or who has been offered stable iodine, then that person should be sent immediately for the rapid screening measurement. Otherwise, send people one at a time for rapid screening as requested by the medical physicist. Pass on the Report form. Do not step onto uncovered floor areas.

• All staff members should remain in the waiting area until the last person has been sent through. Then pass through the monitoring areas to be checked for contamination before leaving the unit.

5J.28 External Contamination Monitoring Area Team

Medical Physicist and Clerk

• Carry out the second stage screening for external contamination, as discussed in paragraphs 5J.13-15. Using an EP15 or similar instrument, scan the body slowly at a distance of about 1cm, concentrating on those areas of the body most likely to have been contaminated (head, hands, elbows, feet, buttocks). The full scan should take at least 3 minutes.

• Identify contaminated areas on the Report form and indicate the measured count rates, and the instrument type. If the person is being re-monitored, indicate that this is the case.

• Where contamination exceeds Action Level B, ask the person to proceed to the decontamination area, first removing and bagging shoes if they are contaminated; overshoes should be provided. Pass the report form to the nurse. On return from the decontamination area, the person should be monitored immediately.

• Where contamination is found to be below Action Level B, ask the person to proceed to the internal contamination monitoring area. Pass the report form to the staff member there.

• Ask for the next person from the waiting area but do not step on to the covered floor area. After all people from the waiting area have been checked and passed through to the internal contamination monitoring area, monitor each other and then proceed into that area to be checked before leaving the unit.

5J.29 Decontamination Area Staff

• Carry out decontamination procedures discussed in paragraphs 5J.10-15. These are similar for Stage 1 and Stage 2, but would clearly be more urgent for Stage 1.

• Ask the person to remove contaminated clothing. This, together with shoes, should then be bagged, given an identifying tag, and stored. A receipt for contaminated clothing, jewellery etc. must be given.

• Encourage and assist the person to remove contamination from the identified area(s) using soap and water. Light scrubbing may be used but care must be taken to avoid damaging the skin, or spreading the contamination to other parts of the body or into cuts and grazes. The person may shower, but it is important to avoid washing radioactive material into the nose or mouth. Ordinary towels should be used for drying; they should then be bagged and stored.

• Provide any necessary alternative clothing.

• Ask the person to go to the external contamination monitoring area. Pass the Report form to the staff member there.

• Do not enter the external contamination monitoring area until all persons have been checked. Then proceed to the external contamination monitoring area to be monitored.

5J.30 Internal Contamination Monitoring Team

• Carry out the internal contamination monitoring as described in paragraphs 5J.16-20. Using Mini Instruments Type 44A or similar instrument, position the end of the probe at the front of the neck, as close as possible without making contact. The measurement should take approximately one minute.

• Record the measured count rate and ask the person to proceed to the Physicist in Charge. Pass on the Report form.

5J.31 Physicist in Charge

• Supervise the layout of the RMU before admission of the first person. People may be allowed to proceed to the reception and waiting areas once they are ready and staffed. Subsequent preparation of the RMU will then be carried out from the internal contamination monitoring end.

• Once people have entered the external contamination monitoring area, there must be no movement of staff against the direction of flow (with the exception of any staff member assigned to contamination control).

• Depending on the level of contamination found, decide what further external or internal contamination measurements are necessary and give each person an information sheet (see Report form). Arrange for attendance at an Uptake Measurement Unit if appropriate. Record the details in sections 10 and 11 of the form.

• Discuss with the Radiation Protection Adviser the arrangements for dealing with contaminated clothing and valuables. Consider decontamination of any clothing and provision of alternative outdoor clothing.

5J.32 Decommissioning of the Radiation Monitoring Unit

• The Physicist in Charge will be responsible for planning and carrying out decommissioning of the unit.

• When all people have passed through the RMU, a full survey of all areas including the entrance should be made to identify contaminated surfaces. All contaminated objects should be placed in polythene bags. Contaminated sheeting should be folded and also placed in polythene bags.

• All bags containing contaminated waste should be sealed, labelled with the maximum count rate measured at the surface of the bag, and removed for storage. Request advice from the Radiation Protection Adviser on disposal.

• A final radiation survey should be arranged before the area is put back into general use.

Operational Protocol for a Nuclear Weapons Accident

5J.33 Similar arrangements for external contamination monitoring as for a nuclear reactor accident could be put in place. The relevant stages in the screening process are those shown in the preceding flow diagram above the line A---B (see para 5J. 6).

5J.34 Contamination would be by alpha-emitting radionuclides, and so action levels would need to be set on the basis of inhalation or ingestion of material deposited on the skin, rather than on the basis of deterministic effects to the skin. If it is assumed that activity distributed over an area of skin of 10cm ² might be inhaled before the contamination is removed by normal processes, then a committed effective dose of the order of 10 mSv could result from an activity concentration of the order of 30 Bq cm ^-2 of ²³⁹Pu oxide. A value for Action Level A set so as to identify this level of contamination would correspond to a reading on an EP15 contamination monitor of 15 counts per second at a distance of 1 cm. (Note that although not intended for alpha measurements, this type of instrument is sensitive to alpha radiation.) A value for Action Level B would be determined from a consideration of available resources, as discussed in previous sections.

5J.35 External contamination screening measurements could be used to prioritise people for subsequent internal contamination measurements. These would include radiochemical analysis of urine and faecal samples, and lung monitoring using specialised detectors. Facilities for carrying out such measurements are available primarily within the nuclear industry. The NRPB would advise on available resources. Assistance would be provided by MoD personnel at the site of the accident.

SUGGESTED LIST OF SPECIALISED EQUIPMENT FOR RADIATION MONITORING UNIT

Equipment for controlling movement
Warning signs
Barrier tape
Barriers

Protective clothing
Paper Coveralls (e.g., Tyvek)
Latex gloves (large, medium, small)
Plastic overshoes

Material for prevention of contamination
Tacky mats
Small polythene bags
Polythene sheeting and Kraft paper
Vinyl sealing tape

Personal decontamination equipment
Mild soap
Lanoline
Dilute Cetrimide
Plastic sponges
Soft nail brushes
Towels
Polythene bags (to hold clothing etc.)
Adhesive labels with trefoil symbol
Disposable trousers, tops, slippers

Building decontamination equipment
Polythene buckets
Decon
Soap powder
Plastic sponges
Scrubbing brushes

Stationery and communications
Record forms, Information sheets
Notebooks
Wax pencils
FAX machine

Monitoring instruments

See paragraph 5J.4

DO NOT UNDER-ESTIMATE THE AMOUNTS REQUIRED

EXAMPLE OF A SUBJECT REPORT FORM

QUESTIONNAIRE FOR USE AT RADIATION MONITORING UNIT

A. To be completed on arrival

1. Name (Title, Forename, other initials, Surname):

2. Have you been asked:

3. Date of Birth (Day/Month/Year):

4. Sex:

5. Address:

6. Date and time of arrival at Radiation Monitoring Unit:

7. Details of movement during the emergency:

8. Have you seen or been treated by your GP or any hospital within the past month? If so, please give details:

9. Name and Address of GP:

B. To be completed after monitoring, form to be retained by Physicist in Charge

10. Report Form issued:

EXAMPLE OF A MONITORING/CONTAMINATION REPORT FORM

EXTERNAL CONTAMINATION REPORT FORM

To be retained by the Physicist in Charge

INTERNAL CONTAMINATION REPORT FORM

To be retained by the Physicist in Charge

REPORT FORM

(Delete paragraphs not applicable)

To be retained by the person monitored

YOU ATTENDED THE RADIATION MONITORING UNIT

AT ..................................................................... ON ..................................................................

11 Monitoring has been carried out, and no radioactive contamination has been detected. No further action is required.

12 Monitoring has been carried out. A small amount of radioactive contamination has been detected on your skin. You are advised to return home, take a shower or bath as soon as convenient, put on clean clothes and wash those you were wearing; no further action beyond this is required.

13 Monitoring has been carried out. A small amount of radioactive contamination has been detected on your skin. You should have already been offered facilities to wash, and to change your clothing, in order to remove this material. No further action is required.

14 Monitoring has been carried out. A small amount of radioactive contamination has been detected on your skin. You should have already been offered facilities to wash, and to change your clothing, in order to remove this material. You should attend the Uptake Measurement Unit at ..................................................................... hospital for follow-up measurements. The hospital Medical Physics Department will contact you within a few days with appointment details. Further information and advice will be given.

15 Monitoring has shown that you may have swallowed or inhaled small amounts of radioactive material. You should attend the Uptake Measurement Unit at ...................................................................... hospital for follow-up measurements. The hospital Medical Physics Department will contact you within a few days with appointment details. Further information and advice will be given.

Other Information:

If you have any concerns or wish to discuss this matter further, please contact your GP.

Signed ........................................................... Physicist in Charge .............................................