Design study on large scale fast breeder reactor plant, The farst half of the 1991; Research results of thermal characteristics for cooling system in regrand to feasibility of a hot standby

Ohtaki, Akira 

A Hot Standby examined through the design study of 600 MW, class FBR aims at maintaining the coolant temperature at about 300C for 48 hours or more after breaking out a trip, in order to relax the thermal transient on Cooling Systems and to make restarting the plants easier. To pick up problems of Hot Standby, the heat loss, the weight of structure and coolant on this plant are calculated a based on the design in 1990, and the thermal characteristic of the heat transport systems are analysed with Super-COPD using abore input data. And the conditions needed to Hot Standby are clarified. In this report, research related to an evaluation method of feasibility and so on are obtained as follows : (1)This plant thermal response behaves similarly with MONJU. (2)The Air Cooler is the maximum source of the heat loss so as in MONJU. (3)The heat loss in the whole system are estimated as 3.2MW in rated output, and 3.3 MW when system temperature is 300C after the Decay Heat Removal operation. (4)The duration heat sink time when the inlet temperature of reactor vessel drops to 300C is about 14 hours and the droprate is about 3.5C/h. (5)The whole input heat value of the circulation pumps at the rating flow is estimated as 8.1 MW and therefore affects to heat sink. Ebalancing heat gain including the decay heat with system heat loss by manipulating the pumps enables to control the temperature. After this, the plant operating method should be defined and the estimation method will be provided.