Report of investigation on the radiation leak of the atomic powered ship 'Mutsu'

Radiation leak of the atomic powered ship Mutsu was investigated. The radiation leak from the reactor shield was caused at the time of the test run, and serious social and political problem was raised. The phenomena is the streaming of neutron and caused by the technical lack of designing. There were, however, many cause of this technical lack. The organization for construction of the ship Mutsu was politically incomplete, the system of the organization was changed frequently, and then it was very hard to call together qualified engineers. Check of the design and the mock-up test were incomplete, and improvements of design in the course of construction was not made. Responsibilities of the persons in charge were not clear. Contract concerning the shield was defective. This report proposes improvement on the above mentioned problem. (Kato, T.)