Jellyfish Shut Down Nuclear Plant

Chain of Salps

Technically, not jellyfish, but salps

The workers of the Diablo Canyon nuclear power plant received a very slimy surprise this week when they discovered hoards of jellyfish-like creatures clinging to the structure, leading to the shutdown of the plant.

The organisms, called salp, are small sea creatures with a consistency similar to jellyfish.

The influx of salp was discovered as part of the plant’s routine monitoring system, according to Tom Cuddy, the senior manager of external and nuclear communications for the plant’s operator, Pacific Gas & Electric.

“We then made the conservative decision to ramp down the affected unit to 20 percent and continued to monitor the situation,” Cuddy said. “When the problem continued, we made another conservative decision that it would be safest to curtail the power of the unit.”

The salp were clogging the traveling screens in the intake structure, which are meant to keep marine life out and to keep the unit cool.

“Safety is the highest priority,” Cuddy said. “We will not restart the unit until the salp moves on and conditions improve. No priority is more important than the safe operation of our facility.”

Hogchoker (Trinectes maculatus)

My local power plant, Calvert Cliffs has had problems with organisms causing problems with it's intakes.  While salps are not found in the more brackish region of the Bay, in at least one instance, a small flatfish, called the Hogchoker, has been pushed into the intakes in such numbers that the plant was at least forced to slow. We have lots of jellyfish, many more than I expect even a bad salp bloom could be in the Pacific, but likely our plant is designed to accommodate them.

Like Diablo Canyon, CCNPP have traveling screens to screen out organisms and large debris, and the place where they dump back into the Bay is one of my favorite places to fish.  The material coming out of the screens acts as a chum line, and often attracts many Stripped Bass.  I call them the "Pez Dispensers" because often you can pop multiple stripers out of a small area one after another.