An independent committee that evaluates safety at the Diablo Canyon Power Plant reviewed new data that shows the plant’s Unit 1 still meets federal safety standards at a meeting in Avila Beach this week.
Over time, metal exposed to radiation can become prone to cracking in a process called “embrittlement.”
Diablo Canyon has now run for 41 years, and the strength and flexibility of the metal plates and welds that make up its reactor vessel has been a point of concern for anti-nuclear advocates, regulators and nuclear scientists.
PG&E, the utility that operates Diablo Canyon, hired the consulting firm Westinghouse to test the metal in Diablo Canyon’s Unit 1 to see if it’s still resilient to cracks.
Westinghouse hammered metal samples taken from inside the unit’s reactor vessel to quantify how much energy is required for them to break.
The Diablo Canyon Independent Safety Committee, created by the state’s Public Utilities Commission, hired nuclear engineer Mark Kirk to evaluate the results.
At this week’s committee meeting, Kirk said he assessed and found credible Westinghouse’s results that show the plant will meet federal safety standards until at least 2045.
“I feel very confident in saying that this is not a particularly controversial set of data,” Kirk said.
Committee member and nuclear engineer Raluca Scarlat, who also reviewed PG&E’s results, said Diablo Canyon is safe to operate, but she still wants even more information to prove that the metal samples were tested properly.
“Okay, it came out of the capsule,” she said of the metal samples. “So then what happened? And how do we know that the data generated is the correct value?”
The Diablo Canyon Independent Safety Committee voted for Scarlat’s recommendation for more review.
Assembly Member Dawn Addis, whose district includes San Luis Obispo County, spoke at the meeting and said she supported third-party verification of the testing results.
“ I don't think we can accept just what PG&E or Westinghouse or the [Nuclear Regulatory Commission] are saying to us,” she told the committee. “I do think those entities have become too susceptible to politics and their own bias, even if it's unconscious bias.”
According to state law, Diablo Canyon is scheduled to close in 2030, but the legislature will very likely revisit extending the power plant’s operations next year.
Disclosure: PG&E is a financial supporter of KCBX.
