Emergency Diesel Generator

Photo by J.A. Gonyeau

Every nuclear power plant has emergency power supplies, which are often diesel-driven. These generators provide power only when needed to special safety electrical distribution panels. These panels in turn supply power to those emergency pumps, valves, fans, etc. that may be required to operate in the event of the postulated catastrophic event - a simultaneous total loss of outside power and a major break in the reactor coolant system.

Emergency equipment is redundant with totally separate emergency electrical power supplies. The premise in nuclear power is that emergency equipment must be single failure-proof. This should guarantee that at least one channel (or "train") of emergency equipment will function. In a few cases, a plant may have 3 redundant trains of equipment for some emergency systems.

Copyright 1996-2004.  Joseph Gonyeau, P.E.. The Virtual Nuclear Tourist. All rights reserved. Revised: March 15, 2001.