Investigation on integrity of JMTR concrete structures, cooling system and utility facilities

The condition of facilities and components to be used for re-operation of the Japan Materials Testing Reactor (JMTR) from FY2011, was investigated before the refurbishment work. An investigation of aged components (aged-investigation) was carried out for concrete structures of the JMTR reactor building, exhaust stack, trench, canal, filter banks and for aged components of tanks in the primary cooling system, heat exchangers, pipes in the secondary cooling system, cooling tower, emergency generators and so on, in order to identify their integrity. The aged-investigation was carried out from the beginning of FY2007. As a result, cracks of concrete structures such as the exhaust stack, a foundation of the UCL (Utility Cooling Line) elevated water tank were repaired and pipe linings of secondary cooling system were replaced. Motors of primary cooling pumps, pumps in the secondary cooling system and in other systems were decided to replace from viewpoints of future maintenance and improvement of reliability. Other components and the reactor building were decided to use continuously for a long-term by appropriate maintenance activities based on the long-term maintenance plan. In this paper, the aged-investigation for the JMTR reactor building, heat exchangers and emergency generators is presented. (author)