Answer to Question #282 Submitted to "Ask the Experts"

Q

I need some case histories of accidents or problems involving irradiators. Do you know where I can find two or three?

A

Following are summaries of three International Atomic Energy Agency (IAEA) publications on accidents at irradiation facilities. These can be reached via the publications section of the IAEA Web site or you may wish to order the referenced books.

The Radiological Accident at the Irradiation Facility in Nesviz—On 26 October 1991, a fatal radiological accident occurred at an industrial sterilization facility in Nesvizh, Belarus. Following a jam in the internal product transport system, the operator entered the irradiation chamber to clear the fault. In doing so, he bypassed a number of safety features, leaving the controls in a position such that exposure was imminent. It was estimated that he received a whole-body dose of 11 Gy, with localized areas of up to 20 Gy. Despite intensive medical treatment, he died 113 days later. The significant feature of this case was related to the medical management. In its post-accident review, the IAEA also brought to light other circumstances of the accident. The present report documents the causes and consequences of the accident and defines the lessons learned with a view to assisting those people with responsibility for the safety of such facilities and those medical authorities who might be involved in the management of a radiation event. Contents: (1) Introduction, (2) Irradiation facility, (3) radiation accident, (4) Dose estimation, (5) Lessons learned, (6) Medical management, Annex I: Estimation of whole body dose from blood cell counts, Annex II: Results of cytogenetic analyses, Annex III: List of drugs, doses, and administration dates. French, Russian, and Spanish editions planned. STI/PUB/1010 (76 pp., 37 figures; 1996) E ISBN 92-0-101396-5 Price: 280 Austrian Schillings

The Radiological Accident in San Salvador—On 5 February 1989, a radiological accident occurred at an industrial irradiation facility near San Salvador, El Salvador. Medical products are sterilized at the facility by irradiation by means of an intensely radioactive ⁶⁰Co source in a movable source rack. This source rack became stuck in the irradiation position. The operator bypassed the irradiator's degraded safety systems and entered the radiation room with two other workers to free the source rack manually. The three men were exposed to high radiation doses and developed acute radiation syndrome. They received initial hospital treatment in San Salvador and subsequent, more specialized treatment in Mexico City. The legs and feet of two men were so seriously injured that amputation was required. The worker who had been most exposed died 6 1/2 months after the accident from lung damage due to irradiation complicated by injury sustained during treatment. The report describes the accident and the response to it and presents lessons derived for operators and suppliers of irradiators, national authorities, medical staff, and international organizations. Detailed information on dosimetric and medical aspects of the accident is presented in appendices and annexes. Contents: (1) Introduction, (2) The background in El Salvador, (3) The irradiation facility, (4) The accident, (5) The response to the accident, (6) Factors contributory to the accident, (7) Generic lessons learned, Addendum, Photographs, Appendix I: Dosimetric analysis, Appendix II: Medical treatment, Annexes I and II: Patients A and B: Nutritional reports by the Angeles del Pedregal hospital in Mexico City. STI/PUB/847 (94 pp., 24 colour photographs, 20 figures; 1990) E ISBN 92-0-129090-X F ISBN 92-0-229090-3 R ISBN 92-0-400292-1 S ISBN 92-0-329091-5 Price: 340 Austrian Schillings

The Radiological Accident in Soreq—On 21 June 1990, a fatal radiological accident occurred at an industrial irradiation facility at Soreq, Israel. An operator entered the irradiation room by circumventing safety systems and was acutely exposed with an estimated whole body dose of 10-20 Gy. The accident, like earlier accidents at similar irradiators, was the consequence of the contravention of operating procedures. An IAEA review team investigated the causes of the accident. This report presents its findings and recommendations and describes the clinical management of the patient, particularly of the haematological phase. The medical treatment included the use of emerging therapies with haematopoietic growth factor drugs which may rescue the overexposed patient, albeit in this case only temporarily. The report is intended for regulatory authorities responsible for the regulation and inspection of irradiators, operating organizations, and physicians who may need to treat overexposed patients. Contents: (1) Introduction, (2) The irradiation facility, (3) Regulatory control, (4) The accident, (5) Actions and lessons, (6) Overview of the medical aspects, (7) Medical management of the patient, (8) Findings of the postmortem investigation, (9) Lessons to be learned. STI/PUB/925 (78 pp., 14 figures + 32 illustrations; 1993) E ISBN 92-0-101693-X Price: 300 Austrian Schillings