was re-irradiated in an area after he had already been treated. According to doctors, his condition is now satisfactory. An overexposure of a patient occurred on December 24, 2008 during external radiotherapy during control exposures before a second treatment stage. According to the medical team, the patient’s condition who is receiving special follow-up is currently satisfactory. On June 15, 2007, when a patient was irradiated, the manipulator was still in the treatment room. Based on the effective dose received (approximately 30 mSv), no health effects were expected for this person.
Table 1.2. The ASN-SFRO classification for radiological accidents (adapted from the ASN [ASN 13]. (1) Common Terminology Criteria for Adverse Event, Cancer Therapy Evaluation Program, August 2006, http://ctep.cancer.gov
| Events (unforeseen, unexpected) | Causes | Consequences (CTCAE V3.0 grade) | |
| 5–7 Accidents | Death | Dose (or volume irradiated) much higher than normal resulting in complications or outcomes not compatible with life | |
| 4 Accidents | A serious life-threatening event, complication or disabling condition | Dose or volume irradiated much higher than tolerable doses or volumes | Severe, unexpected or unpredictable acute or late reaction, grade 4 |
| 3 Incidents | An event causing severe alteration of one or more organs or functions | Dose or irradiated volume greater than tolerable doses or volumes | Severe, unexpected or unpredictable acute or late reaction, grade 3 |
| 2 Incidents | An event that causes or is likely to cause moderate impairment of an organ or function | Dose higher than recommended doses or irradiation of a volume that may result in unexpected, moderate complications | Moderate, unexpected or unpredictable acute or late effect, grade 2, minimal or no change in quality of life |
| 1 Event | Event with the dosimetric consequence but no expected clinical consequence | Dose or volume error: for example, dose error or target error during a session that cannot be compensated for over the entire treatment | No symptoms expected |
| O event | Event without any consequences for the patient | For example, error in identifying a patient treated for the same pathology (compensable) |
Table 1.3. Procedure for the classification of an event on the basis of exposures or health consequences related to doses received [ASN 08b, IAE 13]
| Event | Number of individuals and final ranking | ||
| Minimum ranking | Number of individuals | Final ranking* | |
| Death or lethal dose received | > 10 | 6 | |
| 4 | > 1 | 5 | |
| 1 | 4 | ||
| Deterministic effect or potential deterministic effect with respect to the dose received | > 10 | 5 | |
| 3 | > 1 | 4 | |
| 1 | 3 | ||
| Exposure greater than 1 Sv or 1 Gy | > 100 | 6 | |
| 4 | > 10 | 5 | |
| ≤ 10 | 4 | ||
| Exposure greater than 100 mSv | > 100 | 5 | |
| 4 | > 10 | 4 | |
| ≤ 10 | 3 | ||
| Exposure of worker(s) to a dose above the annual regulatory limit or of a member of the public to a dose above 10 mSv | > 100 | 4 | |
| 2 | > 10 | 3 | |
| ≤ 10 | 2 | ||
| Exposure of worker(s) to a dose above the annual regulatory limit or of a member of the public to a dose above 10 mSv | > 100 | 3 | |
| 1** | > 10 | 2 | |
| ≤ 10 | 1 | ||
* The highest ranking should be selected. ** When a dose limit is exceeded as a result of the accumulation of exposure over a certain period of time, the ASN systematically assigns a level 1 classification for lack of a safety culture.
1.4. The typology of accidents
Nuclear accidents can be of many different types. Criticality accidents that emit large quantities of neutrons and ionizing radiation are often lethal to workers. Industrial accidents due to fire, lightning, earthquakes, tsunamis and so on can damage any protective measures leading to leaks of radioactive materials. However, radiological protection is rarely broken leading to level 4 accidents. The occurrence of a level 5 accident requires an additional supply of energy. This has already occurred in the case of a core meltdown or could occur during an external attack such as a plane crash or a hollow charge shot (ammunition allowing the armor to be pierced).
1.4.1.