Diablo Canyon Decommissioning Engagement Panel

Public Comments

DateDecember 4, 2020
Decommissioning TopicSafety
Comment / Suggestion:

Dear Chuck and members of the DCDEP:

It appears that the Diablo Canyon Unit 2 main stator, barely one year old, has now failed for a third time after this recent attempted restart (this following a 46 day outage, which followed the 2 week outage back in July). Aside from any safety implications (and PG&E’s stated need for the replacement was to maintain safety) the troubling history of repeated failures of a new “replacement” part is reminiscent of the way the San Onofre nuclear plant’s history unfolded. In that instance, problems also emerged barely a year after the steam generators were replaced, and it was discovered that the flawed design and manufacturing process had created conditions of premature degradation. As full replacement (of the replacements) was deemed the only solution, SCE considered it too expensive and the plant was retired.

While we will need to await any full evaluation of the stator failures at Diablo Canyon, should a San Onofre style situation emerge, the County and the DCDEP may wish to remain cognizant of how this harbinger could alter the timeline for decommissioning and thus also the economic forecast and trajectory of the district in accelerating the closure of Diablo Canyon.

Kindly feel free to reach out to The Alliance with any questions or concerns.

Hoping that you and your staff are remaining well and healthy during this pandemic.

Yours truly,


Alliance for Nuclear Responsibility
PO Box 1328
San Luis Obispo, CA 93406
(805) 704-1810 cell


CA Current
Diablo Canyon Unit Down Again

3 Dec 2020

One of two main units at the Diablo Canyon Nuclear Power Plant is down for the third time. Soon after Unit 2 was restarted over the Thanksgiving weekend after a month-and-a-half long outage, Pacific Gas & Electric again had to take it offline. The problem continues to be with an electric generator component that was rebuilt last year.

“Operators have previously taken the unit offline twice this year to allow for needed maintenance on this component, which had been refurbished in 2019 and is located on the non-nuclear side of Unit 2,” PG&E stated the evening of Dec. 2.

After the 1,150 MW Unit 2 went back online on Sunday, Nov. 29, the Alliance for Nuclear Responsibility questioned whether the second repair of a key electric generation component, known as a stator, would be lasting, or was a mere band-aid.

“Two days later, PG&E has apparently attempted to hose the stator down and its soggy band-aid sits on the floor in the shower,” David Weisman, Alliance spokesperson, told Current.

Ratepayers paid $100 million for the stator replacement.

What is the cause of the hydrogen leak, who pays for the repair, and whether there are plans for special monitoring to catch subsequent leaks, are among the Alliance’s questions.

PG&E did not respond to Current’s requests for answers to those queries.

Alliance’s request for ratepayer refund denied

The Alliance challenged PG&E’s request for full rate recovery of the replaced stator but was unsuccessful. On Thursday, state regulators approved raising PG&E revenue this year to $9.1 billion. Its decision included denying the organization’s recent request to return $12.5 million of the $100 million rebuild tab to ratepayers, though the commissioners may not have been aware of the third Unit 2 outage.

Diablo’s other operating unit, which was shut down for planned maintenance and refueling starting Oct. 3, resumed sending power to the grid Nov. 9.

The entire 2,200 MW nuclear plant was offline when the grid operator called for conservation on Oct. 15 because of spiking temperatures.

The Alliance has argued that electricity from Diablo has been significantly more expensive than other sources the last three years. It recently told the CPUC that in 2018, consumers paid $410 million extra for this above-market power, and that amount soared to nearly $1.3 billion this year. It estimated that ratepayers will have paid $5-6 billion in higher electricity costs by the time the two nuclear units are retired in 2025.

—Elizabeth McCarthy

Group Affiliation, if any (Optional)Alliance for Nuclear Responsibility
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