S-PRISM

PRISM (Power Reactor Innovative Small Module, sometimes S-PRISM from SuperPRISM) is the name of a nuclear power plant design by GE Hitachi Nuclear Energy (GEH).

The S-PRISM represents GEH's Generation IV reactor solution to closing the nuclear fuel cycle and is also part of its Advanced Recycling Center (ARC) proposition to U.S. Congress to deal with nuclear waste. S-PRISM is a commercial implementation of the Integral Fast Reactor developed by Argonne National Laboratory between 1984 and 1994.

It is a sodium-cooled fast breeder reactor, based on the Experimental Breeder Reactor II (EBR-II) design, scaled up by a factor of ten.

The design utilizes reactor modules, each having a power output of 311 MWe, to enable factory fabrication at low cost.

In an identical fashion to the EBR-II that it is based on, the reactor would transition to a much lower power level whenever temperatures rise significantly, moreover the reactor vessel modules are pool type, as opposed to loop type, with the pool conferring substantial thermal inertia and the final key safety feature includes a "RVACS", which is a passive reactor vessel air cooling system to remove decay heat. These safety systems are passive and therefore always operate and are to prevent core damage when no other means of heat removal are available.

The integral fast reactor was developed at the West Campus of the Argonne National Laboratory in Idaho Falls, Idaho and was the intended successor to the Experimental Breeder Reactor II, which achieved first criticality in 1965 and ran for 30 years. The Integral Fast Reactor project was shut down by the U.S. Congress in 1994.

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