Ethics Guidelines
Part B - Guidelines for Projects Involving Ionising Radiation
Section 12 - Working Rules
Note that a comprehensive guide of laboratory working rules can be found in the Australian Antarctic Division's (AAD's) Ionising Radiation Safety Manual. Each project will be issued a manual into which their working rules should be inserted.
12.1 A set of working rules covering the operational use of radioisotopes shall be formulated for each project using radioisotopes. These working rules are part of the final approval stage and should be submitted and discussed with the AAD's RSO three months prior to anticipated use (see section 14.2). Both the users and the Site RSO with the AAD's RSO shall discuss the working rules before departure to Antarctica. These working rules shall be kept under ongoing review and updated and modified as appropriate.
12.2 The working rules shall address:
12.2.1 Safe operation with the aim to keep exposures and contamination as low as reasonably achievable.
12.2.2 Prevention of radiation accidents.
12.2.3 Prevention of cross contamination between radioactive sources and the measurement of naturally occurring isotopes.
12.3 An important part of preparing the working rules is examining the operation and identifying credible radiation accidents. The working rules shall include procedures to be followed to minimise the possible occurrence of potential accidents. The sort of accidents considered for unsealed radionuclides include spillage, breakage, fire, flood and possibly minor explosions.
12.4 The working rules shall incorporate any relevant Australian Antarctic Division (AAD) rules. To this end, the AAD Laboratory Manager shall be consulted and all guidelines in the AAD Ionising Radiation Safety Manual shall be studied and followed.
12.5 The working rules for unsealed nuclides shall address the following points. This is a sample list and is not to be taken as exhaustive.
12.5.1 Instructions on personal monitoring, including how and when to use personal monitoring.
12.5.2 Reminders that smoking, eating and drinking are not permitted in the radioactive materials laboratory.
12.5.3 A reminder that food and drink may not be brought into the radioactive materials laboratory (eg. the refrigerator).
12.5.4 Prohibition of mouth pipetting of all liquids (whether radioactive or not) in any area assigned for storage or use of radioisotopes.
12.5.5 A reminder that appropriate protective clothing should be worn when handling radioisotopes. What constitutes appropriate clothing will depend on factors such as the radioisotope, the quantity, the operation and the working conditions. When working in the laboratory the operator shall wear a laboratory coat, gloves and plastic "overshoes" as a minimum. Field clothing should be suitably protective against contamination and easily decontaminated. The choice in suitable outer field clothing in the Antarctic may be constrained by other factors, but a proper effort should be made to achieve satisfactory protection against contamination.
12.5.6 Procedures for monitoring hands, footwear and clothing for evidence of the contamination to be carried out at appropriate points during the procedure and at least after each procedure. Thorough checking shall be carried out before leaving the laboratory. Laboratory coats should be placed in washing/disposal bins, and gloves and plastic overshoes should be disposed before leaving the laboratory.
12.5.7 Procedures for minimising the spread of contamination due to either droplets falling in the wrong place, or spillage. The following should be addressed:
i) Bringing the radioisotope from the store in such a manner as to minimise the risk of spillage or other accident.
ii) Drawing the radioisotope off and handling it in such a manner as to minimise the risk of contamination and particularly to contain contamination if it occurs. To this end a multiple containment system is recommended. For example, the first containment would be the container itself. The second containment might be plastic-backed absorbent paper, plastic side down. The third containment might be an impervious tray or pan under the paper in order to ensure containment of spills. The fourth containment might be a fume cupboard sink over which or within which the operation is taking place. The fifth containment might be the laboratory itself, constructed to the required standards as a radioisotope laboratory. An important part of the containment process, applicable to all levels of containment, would be the use of the contamination meter to detect patches of contamination. Detection and removal of contamination prevents breaching of the containment system by spreading of contamination by persons moving in and out of the laboratory. Proper protocols for entry to, and exit from, the laboratory and proper use of protective clothing will support the successful operation of a multiple containment system.
12.5.8 For gamma emitters, the TIME/ DISTANCE/ SHIELDING concept shall be utilised to minimise dose received during the procedure.
12.5.9 Records shall be kept, as detailed in section 6 of these guidelines.
12.5.10 Clean up of contaminated equipment and areas including preparation of resultant waste for return to Australia. The AAD Ionising Radiation Safety Manual contains details of these procedures.
12.5.11 Protocols for maintaining good personal hygiene, for example:
- keep fingernails short and clean;
- either use 'double gloving' technique or forego use of unsealed radioisotopes if there is broken skin below the wrist;
- wash hands and arms thoroughly before handling any object which goes to the mouth, nose or eyes.
12.5.12 Details of emergency procedures shall be readily available in all work areas.
12.5.13 Signs shall be posted while carrying out of procedures. The AAD Ionising Radiation Safety Manual contains details of appropriate signs.
12.5.14 Identification and isolation of laboratory equipment for use in radioactive procedures.
12.5.15 The AAD Laboratory Manager must be notified of any need for repair, maintenance or removal of equipment from the laboratory.
12.5.16 Reminder that radioactive contamination beyond the primary containment systems (ie. plastic backed absorbent paper, spill tray, etc.) should not occur.
12.5.17 Decontamination procedures where the decontamination does not rate as an emergency.
12.5.18 A summary of the identified credible accident scenarios shall be identified and the working rules instituted to minimise (or effectively eliminate) the opportunity for occurrence of the specified scenarios.
12.5.19 The location and maintenance of any equipment needed to respond to an emergency. Equipment location shall be clearly sign-posted as required in AS2243 - Safety in Laboratories.
12.5.20 Prevention of cross contamination between radioactive sources and measurement of naturally occurring isotopes.
12.6 Working rules need to be prepared for use of unsealed radioisotopes in the field as well as in the laboratory. The same sort of points need to be addressed but with modification to take account of field conditions. Field working rules should also address the desirability of doing as much laboratory pre-preparation as reasonably possible prior to leaving the laboratory.
Some of the concepts mentioned above in 12.5 can be employed in the field. For instance, if it is necessary to draw up an injection of radioactive liquid in the field, a multiple containment system should be developed. An example of a field multiple containment system might comprise:
- a backpack for carrying the experimental equipment as the outermost containment;
- the next inner containment might be a plastic liner;
- the pack might be secured upright and open with a plastic liner and absorbent material in a depression formed by draping across the throat of the pack, to form the next containment level;
- operations such as drawing up could then be performed in this 'well'.
12.7 Working rules for sealed sources should include relevant points taken from those listed in 12.5 for unsealed sources; plus rules for checking and preserving integrity of the sealed source and its shielding, if any; plus rules for handling the source and/or its unshielded radiation. Other working rules specific to the particular sealed source application should be drawn up in accordance with the aims expressed in 12.2.
(ASP & C)
May 2002
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