Reactor system components (pumps, valves, heat exchangers, tanks, and piping) that are specifically designed to remove residual heat from the reactor fuel rods in the event of a failure of the normal core cooling system (reactor coolant system)
U.S. Nuclear Regulatory Commission (NRC), Full-Text Glossary, Washington, DC, USA 2014. http://www.nrc.gov/reading-rm/basic-ref/glossary/f ull-text.html, (Dzstr/ Disabl Mass Care - Amer) {826}