AGING MANAGEMENT OF CIRUS

摘要

Cirus, a 40 MWt, tank type research reactor located at the Bhabha Atomic Research Centre, is in operation since 1960. In Cirus, heavy water is used as moderator, demineralised light water as primary coolant and natural uranium metal as fuel. The average availability factor had been about 70% till the year 1990 whereafter it started decreasing due to frequent problems with equipment / components. Systematic aging studies were therefore undertaken to assess the condition of structures, systems and components. Based on these studies, refurbishing requirements were identified and a detailed plan was drawn up for refurbishing. Reactor was shut down in October 1997 for execution of refurbishing jobs. This paper presents a summary of the results of aging studies and the refurbishing plans. Details of core unloading to facilitate refurbishing and some of the important jobs in the primary coolant system relating to pressure testing of primary coolant pipelines and repairs to identified leaky sections are discussed.