10. Hazards and emergencies
Contents
10.2.1 Accidents Involving Radioactive Substances
10.2.2 Accidents Involving X-Ray Generating Equipment
10.3 Reporting Accidents and Dangerous Occurrences / Near Misses
10.5 Decontamination of Surfaces
10. Hazards and Emergencies
10.1 Assessment of Hazards
The Ionising Radiations Regulations 1999 require radiation workers to identify the hazards associated with the work, perform a suitable and sufficient assessment of the risks of the work and implement appropriate control measures to eliminate or minimise the risks of the work. The Project Application form (see appendices 12, 13 and 14), which serves as the risk assessment for radiological work, should be produced and signed by the project supervisor and radiation worker.
The risk assessment should include a justification for the use of radioactive materials. It should also include control measures required to ensure that workers receive a dose that is as low as reasonably achievable and certainly well within dose limit constraints set by legislation.
10.2.1 Accidents Involving Radioactive Substances
Accidental spillage, fire or explosion in an area where work with radioactivity is performed may give rise to internal/external radiation hazards. The quantities presently being stored and used within University premises could result in:
- Dose rates approaching or exceeding the legal limits for radiation workers;
- The air concentration of a radionuclide rising above the level specified in column 4 of Schedule 8 of the Ionising Radiations Regulations 1999.
No attempt should be made to remove radioactive sources from a School/Unit in the event of a fire or flood. In the event of a fire, the Fire Service should be warned of the presence and location of radioactive sources.
10.2.2 Accidents Involving X-ray Generating Equipment
Failure of a safety device on x-ray generating equipment e.g. deviation of the beam, failure of interlock systems etc., could result in a radiation worker being exposed to a significant amount of x-ray radiation. This exposure may lead to significant biological damage e.g. severe localized skin burns that are slow to heal and may require surgery.
10.3 Reporting Accidents and Dangerous Occurrences/Near Misses
All accidents that may have exposed an individual to ionising radiation or Dangerous Occurrence/Near Miss that may lead to a significant accidental exposure of a worker to ionising radiation, should be reported to the URPA, or if he is not available then contact the University Safety Adviser as soon as reasonably practicable. The URPA will take charge of such emergencies. Examples of such accidents include:
- An incident, however minor, in which it is suspected that a person may have been exposed to ionising radiation;
- Any incident in which a person or his clothing may have been significantly contaminated;
- An incident where this is a possibility of radioactive material having entered a worker through an open wound, ingestion or inhalation;
- An incident involving a fire or explosion with damage to the fabric of a room in which radioactive materials are stored;
- A spill involving an activity of > 5 MBq.
A spill of unsealed radioactive source of less than 5 MBq should be reported to the DRPS as soon as reasonably practicable. The School/Unit local rules should specify who spills of < 5 MBq should be reported to and list names of personnel who will take charge of emergency actions.
Records of all such accidents, Dangerous Occurrences/Near Misses and any subsequent decontamination procedures must be kept.
10.4 Emergency Procedures
For Major Accidents / Incidents See 'Emergency Action'
10.4.1 Immediate Measures
In an emergency it is important to consider the radiation field that may be present, the potential for the ingestion and/or inhalation of radioactivity, the potential for spreading radioactive contamination and the non-radiation hazards (e.g. chemical hazards).
The area/building should be cleared of all unnecessary personnel and the following measures taken as and when appropriate after assistance from the URPA and, if necessary, the emergency services have been summoned:
- Fire or Explosion The emergency procedures in the School/Unit local rules should be complied with. Where it is necessary to obtain the assistance of the University services or any Emergency Services, the DRPS should pass on all relevant radiological information to these services on their arrival.
- Radiation Exposure Persons suspected of receiving a significant radiation dose should be treated as if they were suffering from shock. The circumstances of the exposure should be written down without delay. This information should include (i) the position of the person when exposed, (ii) the duration of the exposure, (iii) the instrument settings if the source is a radiation generator.
- Contamination The decontamination of personnel should be started as soon as possible and any contaminated clothing should be removed. In order to avoid the spread of contamination the contaminated person should not leave the site of the accident. Guidance on the decontamination of personnel is given at the back of this book.
10.5 Decontamination of Surfaces
It is important to delineate the boundaries of contamination before any actions are taken.
a) Very small liquid spills should be dealt with in the following manner:
- Put on disposable gloves;
- Use paper tissues to absorb the spillage;
- Monitor to confirm decontamination;
- Dispose of contaminated tissues in the appropriate designated container.
b) Very small solid spills should be dealt with in the following manner
- Put on gloves;
- Cover the contaminated area with damp paper tissues;
- Mop up with same and dispose of in an appropriate designated container;
- Monitor to confirm decontamination.
If there is a major spillage of radioactivity, then the URPA should be notified as soon as practicable and the decontamination will be organised by the URPA.