A brief history of nuclear criticality accidents in Russia--1953-1997.

Fourteen nuclear criticality accidents that occurred in Russia between 1953 and 1997 are described. These accidents are significant because of the loss of control of special nuclear material and the resultant radiation doses to personnel, potential damage to equipment, and release of radioactive material to the workplace and the environment. A qualitative analysis of the causes and contributing factors to these accidents is presented along with a description of the radiation health effects to workers. The primary cause of most of these accidents was inadequate design that allowed the use of process equipment that did not preclude nuclear criticality on the basis of geometry. Personnel errors and violations of procedures were major contributing factors to these accidents.