Emergency procedures

34

REPORT

OF COMMITTEES

immediately should be segregated into appropriate containers clearly marked with these details. (225) If only short-lived radionuclides are present the material can be stored for decay to levels which permit disposal with ordinary refuse. To avoid the need for long-term storage of longer-lived material, disposal may be arranged, according to local regulations, by incineration, byspecial burial on municipal refuse dumps or by delivery to a special disposal organization. Incineration may, according to the chemical form present, lead to disposal of the radioactive material to the air (e.g. as ‘Hz0 or 14C02)or to retention in the ash. In the latter case the reduction in volume of the radioactive waste may be advantageous provided that no hazard is presented by the handling of this dusty material. (226) Radioactive animal carcasses constitute a special problem. Subject to local regulations these may be disposed of by: (i) (ii) burial under approved incineration, conditions, (iii) maceration and subsequent

AIRBORNE (228) When gaseous radioactive wastes are routinely discharged to the environment, some assessment of the local conditions will be necessary to determine permissible amounts of disposal. Decisions can then be made

12. EMERGENCY

3 AND 4

disposal as liquid waste to the sewers, (iv) preservation and storage for decay of radioactivity, (v) transfer to a special disposal organization. It is particularly important that such carcasses are kept securely so that they cannot be used for human food or become accessible to predators. (227) Carcasses containing r4C or -‘H should be incinerated, when r4C will be released as carbon dioxide, and tritium as water. Incineration can also be used if the carcasses contain short-lived radionuclides in activities up to a few millicuries. However, allowance has to be made for the number of carcasses and the frequency of incinerations. In cases where the carcasses contain large activities or long-lived nuclides, consideration must be given, in relation to the local situation, to determine whether incineration, burial or transfer to a special disposal organization is to be preferred. The ash may contain radionuclides and should therefore be treated with care.

WASTE regarding the height of any stacks or the need to equip ventilation systems with filters. Where large activities of radionuclides are discharged to the atmosphere, it is advisable to ensure the adequacy of the disposal system.

PROCEDURES

GENERAL (229) Radiation incidents are unplanned events during which potential, or actual exposure of personnel is likely to be more than normal for the operation. In this section an accident isconsidered to refer to unplanned events during which potential or actual

exposure of personnel can lead to doses greater than those recommended by the Commission. Such events may occur from maladroit handling, from mislaying of sources, from incorrect administration of large activities of radionuclides, and from

HANDLING,

STORAGE,

USE AND DLSPOSAL OF UNSEALED

fire, explosion etc. In all these events the concomitant or subsequent radioactive contamination shall be considered, but when a fire or explosion has occurred the immediate counter-measure shall be the safeguarding of life and property. (230) It is important that such radiation incidents and accidents be recognized quickly and that the necessary emergency procedures are instituted promptly. This requires advance planning, appropriate training of personnel, issued to all and adequate instructions concerned. Rehearsals shall be conducted from time to time. The authority in charge of the institution shall be responsible for these measures. (23 1) In each room where radionuclides are handled, detailed instructions shall be displayed, setting out the measures to be taken in emergency situations. The name and location of the person responsible for radiation protection in that area shall be clearly indicated. (232) Emergency equipment shall be provided and be readily available. Consideration should be given to the inclusion of the following:

(9 protective (ii) (iii) (iv) (v)

(vi)

clothing, including overshoes and caps, decontamination materials, including absorbent material for wiping up spills, decontamination materials for individuals, and first aid kit, and fencing-off warning notices material, tools, cans and plastic bags for handling, temporary storage and disposal of contaminated articles, portable monitoring instruments, including personal monitoring devices,

KADIATION

ACCIDENTS

35

(vii) sundry items such as adhesive tape, labels, torch, notebook and pencils. Such equipment should be kept on a trolley for convenient transport. (233) A medical casualty service shall be provided. The extent of this service will depend on the radiation risks that may be encountered. In any case, the following provisions shall apply: (i) first aid facilities and advice shall be immediately available, (ii) arrangements for referring casualties and contaminated individuals to medical services at an appropriate stage should be clearly defined and made known. (234) Regarding emergency exposure, the Commission gives the following recommendations in ICRPPublication 9, paragraph loo: “Doses in excess of the limits recommended in paragraph 66 [of ICRPPublication 91 for Planned Special Exposures are acceptable in emergency operations during or immediatelyafter an accident. The justification for this will be the rescue of individuals, the prevention of the exposure of a large number of peopleor thesaving of a valuable installation. It is not possible to specify dose limits for such exposures since the acceptability of the dose will depend on the importance of the objective. In emergency exposures to radioactive materials, it is not possible to predict accurately the magnitude of the intake, and it is therefore unrealistic to specify a limit for the intake. The Commission recommends that, wherever possible, workers should beinformed about the risks before they accept such exposures”.

INVOLVING

(235) In the event of fire, the hazard associated with unsealed radioactive material is relatively small and consequently the first

RADIONUCLIDES

FIRE AND EXPLOSIOSS

concern must be for the safety of patients and staff. (236) Working techniques shall be planned

REPORT OF COMMITTEES 3 AND 4

36

to minimize the risk of fire or explosion as well as to avoid dispersion of activity in the event of such an occurrence (see paragraph 211). (237) Fire-fighting teams who may be involved should receive some instruction on the nature and level of any hazard from unsealed radionuclides so that necessary procedures in an emergency will not be held up by confusion over the extent of any

PROCEDURES

FOR DECONTAMINATION

(239) Minor spills usually involve radioactive substances used for diagnostic purposes. Absorbent paper should be laid immediately over a wet spill. Dry spills should preferably be removed by wet methods, using wet absorbent paper to prevent dispersion. Any paper used should then be removed to a suitable waste receptacle and the affected area monitored. Decontamination should be carried out until the surface activity is below the appropriate level given in paragraph 177. Swabbing should always be done inwards toward the centre of the spill. If contamination levels cannot be sufficiently reduced, the surface should be stripped or covered. In all of these operations, great care should be taken to avoid spread of the radioactivity and to prevent contamination of clothing, skin and monitoring instruments. (240) Major spills are rather infrequent in hospitals but they may occur in connection with therapeutic administration and during pharmaceutical preparation. (241) Until a plan has been worked out for decontamination after major spills, only the minimum emergency action should be taken: (i)

precautions which may be necessary at the time or after control of the fire. Clear instructions shall be provided on how the person responsible for radiation protection precautions at the institute may be contacted. (238) After an explosion has occurred or a fire has been put out, decontamination operations should be entrusted to specially trained teams possessing the proper equipment for this kind of emergency operation.

stop all operations, which, if continued, would add to the contamination, and shut off ventilation, (ii) remove affected clothing and leave it in the contaminated area,

OF AREAS

(iii) evacuate all non-essential staff, and, if necessary, patients from the affected area, ensuring that no person proceeds far into the inactive area until he has been monitored and found to be free from significant contamination. However, treatment of serious injury shall take precedence over decontamination of the victim, (iv) control entry to the area by posting warning notices or other means, (v) notify the technically competent person and the head of the department. The order in which these operations should be done will vary with circumstances; in many cases several will be conducted simultaneously. (242) In the event of significant contamination, the area shall be clearly marked. Access should be restricted to any area of contamination or where the exposure rate from gamma radiation exceeds 25 mR h-l. The technically competent person shall be responsible for controlling necessary actions. (243) Before a contaminated area is used again, a complete radiation survey shall be made by the technically competent person to check that the decontamination procedures have been effective.

HANDLING,

MEDICAL

STORAGE,

USE AND DISPOSAL

YKOCEDUHES

OF UNSEALED

FOR I~ECON’l‘AMINATlON

General (244) All medical

decontamination and treatment procedures shall be planned by the medical adviser after consideration of the relative risks of the likely exposures and of the medical treatment.

Procedures (245) Affected skin should be flushed with

water after a contamination has occurred (see paragraph 188). (246) Since certain additional procedures may be practicable if undertaken very shortly after an external or internal contamination of a person has occurred, the planning referred to in paragraph 244 should include the possibility of personnel being trained to wash the mouth and eyes, and, in appropriate cases, to induce vomiting or to administer blocking and ionexchange material, on the instructions of the medical adviser and while awaiting his arrival (see paragraph 189). (247) Details relating to the incident or accident should be collected at the earliest opportunity for later consideration and review. (248) After first aid procedures have been carried out, monitoring to assess the extent of external and internal contamination shall be undertaken under the supervision of the person responsible for radiation protection in the institute. Any case where the intake is likely to have exceeded the ALI should be discussed at the earliest opportunity with the medical adviser, who will be responsible for any further medical treatment.

RADIONUCLIDES

37

OF PERSONNEL

(249) In order to assist in the estimation of intake and retention of radioactive material it may be important that excreta (urine, faeces, saliva) following the incident be kept in separate containers labelled with the time of collection. On medical advice periodic blood samples may also be advisable. Administrative Procedures (250) A full report shall be prepared

on each radiation accident and submitted to local, and, if appropriate, to other radiation protection authorities. The report should contain all physical and medical information that may be relevant in connection with future planning and preventive measures. (251) When staff is involved, all radiation doses received by them in abnormal circumstances should be recorded and clearly distinguished from exposure incurred during normal operations. If the intake of radioactive material exceeds twice the annual limit the situation should be reviewed by a competent medical authority. The staff member may still be allowed to continue routine work if there is no objection from the medical standpoint, due account having been taken of his previous exposure, health, age and special skills, as well as his social and economic responsibilities. (252) If radioactive material as a consequence of an accident has been or is likely to be released to the environment in substantial activities, the relevant authorities shall be informed immediately subject to local regulations.

13. STORAGE AND TRANSPORT RADIOACTIVE MATERIALS

OF

STORAGE General

(253) In any hospital or medical research institutionusingunsealedradioactivenuclides, one or more suitable rooms or areas shall be

set aside for storage of stocks of radioactive material and, separately, for storage of radioactive waste awaiting disposal (see Section 3). With the types and activities of