Thermal shutoff system

The thermal shutoff system (TSS), separate from the RPS, is designed to automatically shut off the EM pumps on high sodium temperature, in case the heat sink (IHTS) is lost and the RPS fails to scram. For this scenario it is assumed that the loss of heat sink event starts from full power and that neither the PCS nor the RPS can shut down the reactor so that the reactor is left with only RVACS to remove heat. 

Asghari, K., Taabbodi, L., Dong, M.A new gel-foam system for water shutoff purposes in wormhole reservoirs Source SPE/PS-CIM/CHOA International Thermal Operations and Heavy Oil Symposium Proceedings, v 2005, p A423-A428,2005. 

The pressure relief system was not provided primarily to meet code requirements but rather Is an Integral part of the over-all protection system which includes the reactor power setback and scram systems Strict adherence to the code is impractical because the maximum thermal energy output of the reactor cannot be defined. Further at the hifpier conceivable powers fuel melting would probably occur in any event. Prevention of a fuel melting accident with consequent release of fission products depends primarily on the nuclear control and cool ant supply system and only Incidentally on the pressure relief systems. 3 Shutoff valves are not provided at the end of each instrument take-off connection, and the minimum size of instrument take-off connections is not necessarily l/2 or 3/if Inch as required by the ASA Code. 

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