Radiation safety deviations
The use of radiation should not cause additional, unforeseen exposure to anyone. In spite of anticipation, it is not always possible to prevent additional exposure and this situation is called a radiation safety deviation. The consequences of most deviations are quite small, but it is also important to learn from them in order to avoid similar deviations in the future and to reduce the exposure resulting from the deviation.
A radiation safety deviation refers to a situation in which radiation safety is compromised or could be compromised as a result of a deviation. Incidents in health care in which the patient receives radiation exposure that deviates from the plan are also considered radiation safety deviations. When assessing the practices, the most likely and most serious radiation safety deviations are identified. One must be prepared for these and try to prevent them from happening. If the possibility of a significant radiation safety deviation is identified in advance, instructions must be drawn up on how to act in the event of it materializing. The operator must arrange exercises in accordance with the risks associated with the activity on the immediate actions to be taken to limit radiation exposure. In addition, the operator must determine in advance the methods for ascertaining the causes of the radiation safety deviation and for learning from them.
Radiation safety deviations may also constitute radiation hazard situations. In the event of a radiation hazard situation, the consequences of the deviation require or may require special protective measures. The purpose of the measures is to reduce or limit the radiation exposure of persons involved in rescue or protective measures or the population. More detailed information about radiation hazard situations is available on the page Preparedness for radiation hazards.
Radiation safety deviations must be reported to the Radiation and Nuclear Safety Authority (STUK). The manner and urgency of reporting varies according to the severity of the event, its possible consequences and the follow-up measures to be taken. For example, in the event of a radiation hazard situation, the primary point of contact is the emergency response centre, from where the information is directed to STUK. However, some of the deviations have so minor consequences that they do not need to be reported to STUK. Reviewing these deviations is also essential in order to make the necessary changes to the operations to prevent similar types of events in the future.
Examples of reporting different types of radiation safety deviations
A radiation safety deviation with serious consequences or requiring immediate action
In the event of a radiation hazard situation or if instructions or advice are required for handling the situation, the emergency response centre or STUK must be contacted by telephone without delay. A typical example of this type of event is a fire in a place with high-activity radiation sources, an unlawful act against a radiation source, the melting of a radiation source or another radiation safety deviation that results in, or could result in, large-scale contamination.
A radiation safety deviation that must be reported in writing without delay
Typically, STUK is notified of a radiation safety deviation when it has already occurred, and the consequences are already under control. In this case, the notification can be made within a reasonable time, in practice within a few days of the event in writing. The previous notification by telephone must also be confirmed later in writing.
The notification must contain the following information as comprehensively as possible:
- the name of the undertaking and the number of the safety licence;
- the name of the Radiation Safety Officer;
- the name and contact details of the person who submits the report;
- the time and place of the deviation;
- radiation sources related to the event;
- description of the radiation safety deviation;
- information on potentially exposed persons and the radiation exposure caused to them;
- an assessment of any possible radioactive substances released to the environment;
- any immediate measures undertaken;
- the first estimates of the cause of the radiation safety deviation.
The undertaking must draw up a report on the radiation safety deviation that has occurred. In the report, the undertaking must provide more detailed information on the causes and consequences of the radiation safety deviation. The report must describe the measures that shall be taken to prevent similar radiation safety deviations. The notification of a radiation safety deviation may also be report of radiation safety deviation if it includes necessary information.
Examples of radiation safety deviations to be reported without delay
- Radiation safety deviations due to which the radiation safety of the workers or members of the public at the facility and place where the radiation is used or its surroundings may be compromised:
- fire in a place with high-activity radiation sources;
- the exposure of workers or members of the public to industrial radiography;
- higher exposure than the dose limit.
- Situations in which significant unintended medical exposure occurs:
- The dose caused to the patient by electron or photon radiation generated with radiotherapy equipment deviates or could have deviated from the planned total dose by at least 25%;
- The dose caused to two or more successive patients by electron or photon radiation generated with radiotherapy equipment deviates or could have deviated from the planned total dose by at least 5–25%;
- The activity received by the patient in radionuclide therapy deviates or could have deviated from the planned activity by at least 25%;
- The activity received by two or more successive patients in radionuclide therapy deviates or could have deviated from the planned activity by at least 10–25%;
- A wrong patient is exposed when the medical exposure is of class 1;
- The effective dose caused to the patient or to a wrong patient by the examination or procedure is at least 10 mSv;
- The examination, procedure or treatment causes deterministic detriment to the patient as a result of additional radiation exposure;
- The absorbed dose caused to the fetus as a result of additional exposure is over 10 mGy;
- Systematic additional exposure is caused to at least 10 patients and the exposure of a single patient is at least 50% higher than in a planned exposure in a practice of class 1 or 2 medical exposure;
- The situation causes other medical exposure of which it is important to inform other operators to avoid the occurrence of a similar radiation safety deviation.
- Disappearance, unauthorized use and possession of a radiation source requiring a safety licence
- Situations in which the radioactive substance significantly spreads indoors or in the environment:
- breaking of the transport packaging of the radioactive substance and its dispersion into the environment;
- an accident or threat of release of radioactive substances from a facility with a large number of unsealed sources
- Other abnormal observations and information that may be of material significance from the point of view of radiation safety:
- discovered non-identifiable radiation source;
- melting of a sealed source.
Deviations involving medical devices and supplies must also be reported to Fimea, the Finnish Medicines Agency.
Radiation safety deviations with minor consequences
Non-significant medical exposures and minor contamination or other exposure under controlled conditions in health care, industry or research are reported as a summary. Summarized information on these will be reported to STUK annually. The radiation safety deviations concerning the previous calendar year must be reported to STUK by 1 February.
Radiation safety deviations involving unplanned medical exposures which do not need to be reported immediately must be reported as a summary annually.
What STUK does with reported radiation safety deviations
STUK will publish descriptions of reported radiation safety deviations on its website without delay. In this way, the operators can learn from what has happened and take the necessary steps to prevent similar deviations. <linkki anonymisoituihin tapahtumiin> In addition, STUK compiles statistics on radiation safety deviations in Finland and publishes summaries and analyses of them. Statistics and analyses of radiation safety deviations are also prepared to support learning, so that similar deviations can be avoided in the future. Summaries of radiation safety deviations can be found, for example, in the annual reports on the use of radiation. The International Atomic Energy Agency (IAEA) reports on radiation safety deviations in its member states. Significant radiation safety deviations in Finland are also reported to the IAEA annually. All of them must be reported to the Radiation and Nuclear Safety Authority.