Decay heat dump tanks

Power testing of the decay heat removal systems commenced with the filling a steam generator group of one loop on the water side. To start with it was impossible to continue the test at 420°C due to the repair of the dump and leakage hold-up tanks, described lat. As a result of the temporarily insufficient dump tank capacity, the possible necessity of a dumping event was avoided by cautions operation of the main heat transfer sterns at approximately 300X with a main pump speed of about 30%. 

Water/steam side - water flushing operation - steam generator filling and testing of a leg-specific decay heat removal system April/May 1985 interrupted on 13.08.85 until after dump tank repair... 

Gen4 or HYPERION s safety system can remove the decay heat in two ways (1) dumping the steam to the condenser and (2) if first decay heat removal way is not sufficient, back up decay heat removal system is used. This system utilizes natural circulation of primary coolant through bypass path in the core. The surface of Gen-IV module is cooled with latent of heat via water sprays provided by emergency cooling tank. The water inventory in this tank can be injected due to gravitational force to remove the decay heat for 2 weeks. The second system works as a passive safety system. 

In the event of a leak in the system, the U-Bi would be drained to a dump tank. This tank would be provided with adequate cooling to remove the decay heat from fission products. 

Dump tank heating and cooling. When fuel is drained from the primary. system into the dump tanks, fission-product decay produces heat within tluj fuel which must be removed to prevent dump tank metal... 

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