For the first time, a small jellyfish-like animal called a sea salp has forced the shutdown of Diablo Canyon nuclear power plant.
Plant operators and marine biologists say a convergence of natural factors caused the unlikely event.
“Both biology and ocean physics have teamed up against Diablo Canyon,” said Mark Moline, a marine biology professor at Cal Poly.
The event began Tuesday when southerly winds began blowing the salps into the plant’s cooling water intake cove. Plant operators noticed differences in water pressure at the intake structure, indicating the salps were beginning to clog the rolling screens in front of the intake, said Ed Halpin, PG&E’s chief nuclear officer.
“I’ve been very pleased with how staff has reacted to this by putting safety first,” he said.
Operators reduced the power output of the one reactor operating at the time, Unit 2, to 15 percent. The other reactor, Unit 1, had been shut down earlier in the week for regularly scheduled refueling.
On Wednesday, power output at Unit 2 was increased to 24 percent, but a fresh influx of salps overwhelmed the intake screens, which roll in a circular fashion that allow them to be cleaned.
“Last night, the conditions got to the point where we had to shut it down,” Halpin said. “So we’ll have to wait until the salp situation clears up.”
Salps are small marine animals similar to jellyfish that are typically 2 to 3 inches long. They often link together and float in the water in long ropelike formations.
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Diablo Canyon knocked offline, powerless against tiny jellyfish-like creature | The Tribune & SanLuisObispo.com
Plant operators and marine biologists say a convergence of natural factors caused the unlikely event.
“Both biology and ocean physics have teamed up against Diablo Canyon,” said Mark Moline, a marine biology professor at Cal Poly.
The event began Tuesday when southerly winds began blowing the salps into the plant’s cooling water intake cove. Plant operators noticed differences in water pressure at the intake structure, indicating the salps were beginning to clog the rolling screens in front of the intake, said Ed Halpin, PG&E’s chief nuclear officer.
“I’ve been very pleased with how staff has reacted to this by putting safety first,” he said.
Operators reduced the power output of the one reactor operating at the time, Unit 2, to 15 percent. The other reactor, Unit 1, had been shut down earlier in the week for regularly scheduled refueling.
On Wednesday, power output at Unit 2 was increased to 24 percent, but a fresh influx of salps overwhelmed the intake screens, which roll in a circular fashion that allow them to be cleaned.
“Last night, the conditions got to the point where we had to shut it down,” Halpin said. “So we’ll have to wait until the salp situation clears up.”
Salps are small marine animals similar to jellyfish that are typically 2 to 3 inches long. They often link together and float in the water in long ropelike formations.
more
Diablo Canyon knocked offline, powerless against tiny jellyfish-like creature | The Tribune & SanLuisObispo.com