A Generic Approach to Assessing Instrumentation Survivability for CANDUs Plants under Severe Accident Management Conditions

Abstract

The accidents at Chernobyl (1986, USSR, Ukraine), Three Mile Island Unit 2 (TMI-2) and Fukushima demonstrated the critical importance of accurate, relevant, and timely information on the status of nuclear power plant systems during a severe accident. Canadian nuclear power plants were further upgraded following the Fukushima nuclear power plant accident on March 11, 2011. After the implementation of improvements to various plant safety and emergency systems (to enable more effective Severe Accident Management, SAM), it was recognized that further consideration of the plant instrumentation and control systems, intended to be used for the management of postulated severe accidents, is required.

This paper summarizes a generic approach to assessing instrumentation survivability for CANDUs plants under severe accident conditions. The proposed approach and related work flow steps are discussed. Considerations of the impact of the SAM measures on in-plant accident monitoring/instrumentation methods, some insights for ex-plant instrumentation and measurement methods, and R&D needs arising from the assessment are briefly discussed in the paper.