This
nuclear reactor utilizes
natural circulation which is capable of operating at a significant fraction of full power without reactor
coolant pumps. A land-based prototype of the reactor plant was built at
Knolls Atomic Power Laboratory's Kesselring Site in
West Milton, New York. The prototype was used for testing and crew training throughout the 1980s. In 1994, the core was replaced with an
S6W reactor, designed for the new
Seawolf-class submarine. The prototype is equipped with an automatic reactor fill system that can flood the reactor with borated water in the event of a
loss-of-coolant accident. The S8G reactor is in use in s and has a power rating of 26.1 MW. ==References==