Abstracts and Available Papers Presented at the
1998 International RERTR Meeting

REFURBISHMENT, CORE CONVERSION AND SAFETY ANALYSIS
OF APSARA REACTOR

V. K. Raina, K. Sasidharan, S. Sengupta
Bhabha Atomic Research Centre
Trombay, Mumbai - 400 085
India

ABSTRACT

Apsara, a 1 MWt pool type reactor using HEU fuel has been in operation at the Bhabha Atomic Research Centre, Trombay since 1956. In view of the long service period seen by the reactor it is now planned to carry out extensive refurbishment of the reactor with a view to extend its useful life. It is also proposed to modify the design of the reactor wherein the core will be surrounded by a heavy water reflector tank to obtain a good thermal neutron flux over a large radial distance from the core. Beam holes and the majority of the irradiation facilities will be located inside the reflector tank. The coolant flow direction through the core will be changed from the existing upward flow to downward flow. A delay tank, located inside the pool, is provided to facilitate decay of short lived radioactivity in the coolant outlet from the core in order to bring down radiation field in the operating areas. Analysis of various anticipated operational occurrences and accident conditions like loss of normal power, core coolant flow bypass, fuel channel blockage and degradation of primary coolant pressure boundary have also been performed for the proposed design.

Details of the proposed design modifications and the safety analyses are given in the paper.

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