CONTACT: Gary Headrick, San Clemente Green – 949 412 3366; Gene Stone, ROSE, San Clemente – 949 233 7724
Decades-Long Seismic Risk at San Onofre Exposes Failures of Edison & NRC –Environmental Groups Demand Answers
WASHINGTON, May 30 – For nearly three decades, more than 8 million people within 50 miles of the San Onofre nuclear plant have been living with a previously unknown and significant threat to the safety of their communities due to flawed safety equipment and lax oversight. The U.S. Nuclear Regulatory Commission revealed yesterday that emergency diesel generators, required to power the San Onofre nuclear plant in case electrical power is lost, risked being shut down following an earthquake – a problem only discovered two months ago.Local environmental organizations in Southern California have today sent a letter to the NRC demanding answers from both the commission and the nuclear plant operator, Southern California Edison. The letter was signed by Residents Organized for a Safe Environment, San Clemente Green and San Onofre Safety.org.
Southern Californians were stunned to learn that the NRC failed for three decades to examine the impact of an earthquake on the high frequency sensors in the reactors’ emergency backup generators. Edison informed the NRC on May 14 of the discovery that the possibility that a seismic event may cause sensors to shutdown the emergency diesel generators, and that this had not been considered during license assessments for the plant. The Edison document is available here.
Upon discovering the issue, the sensors were immediately turned off, indicating significant concerns regarding the threat these sensors posed to the safety of the reactors. This flaw could have triggered the shutdown of the backup generators following an earthquake. Coupled with an extended loss of offsite power, a valid concern in the earthquake-prone region, failure of the backup generators would cut off essential cooling to both the reactor cores and the spent fuel pools.
The failure of the emergency diesel generators at the Fukushima, Japan, nuclear plant in March 2011 led within a few hours to the start of the meltdown of the nuclear fuel in reactor core in unit 1.
“The failure of the NRC to examine earthquake impacts on critical safety equipment at San Onofre for three decades – a nuclear plant located next to major seismic fault lines – is completely unacceptable,” said Gary Headrick of San Clemente Green, “Community members deserve an explanation from the NRC for this safety failure.”
The San Onofre nuclear plant has been shut down since January following a steam generator tube rupture in Unit 3, which released radioactive steam, and the discovery of excessive wear in the tubes of both units. The steam generators in both operating units had been replaced less than two years ago.
Three technical studies commissioned by Friends of the Earth have detailed the major design changes that have led to the severe damage to the steam generators. <link to reports>. The NRC and Edison are due to report on the failures at San Onofre in the coming weeks.
The misleading information provided Edison regarding the steam generator replacements has raised significant concerns regarding the transparency and safety culture of the operators of San Onofre. The admission that essential emergency diesel generators at San Onofre could be switched off exactly when they are required following an earthquake further highlights the risks of continued operation of the crippled reactors.
The Letter to the NRC: May 31, 2012
Chairman Gregory Jaczko
Nuclear Regulatory Commission
Washington, D.C. 20555-0001
Nuclear Regulatory Commission
Washington, D.C. 20555-0001
Dear Chairman,
We were stunned to learn recently that for nearly three decades the San Onofre nuclear reactors have been operating with inherently flawed backup emergency diesel generators, flaws that could have caused these generators to shut down as a result of a major earthquake. According to documents submitted to the NRC on May 14th of this year by Southern California Edison, the operator of the San Onofre plant, the affect of a major seismic event on the high frequency sensors that would trigger the shutdown of the backup generators had not been analysed. Upon discovering this issue, the sensors were immediately turned off, indicating significant safety concerns.
Allowing the San Onofre nuclear reactors, located directly next to major fault lines, to operate with such fundamental safety issue unexamined for three decades is a dramatic failure on the part of the Commission. The loss of both offsite and onsite power, or station blackout, is the very condition that led to the nuclear catastrophe at Fukushima-daiichi. As you are aware the seismic vulnerability of nuclear reactors has become an even more urgent issue in the aftermath of the Fukushima-daiichi accident. We are well aware of your particular concerns in this area. Tuesday’s news underscores the need for immediate and urgent action.
This critical safety flaw, only now revealed, posed an unacceptable risk to the 8 million people who live within 50 miles of the San Onofre nuclear plant and the untold numbers that would be affected by radioactive fallout from a catastrophic accident at this plant. We are writing today to demand a public explanation from the NRC as to how the Commission could fail so drastically to fulfil its responsibility to our families, our communities, and the citizens of this country to ensure the safety of San Onofre.
This critical problem with the emergency backup generators, and the astounding amount of time before the issue came to light, is but one example of the perfunctory oversight and pervasive lack of safety culture within the NRC and the nuclear industry.
The San Onofre nuclear reactors have been offline for four months due to the rupture of tubes in the recently replaced steam generators. Southern California Edison presented this as a like-for-like replacement, and the Commission rubber-stamped the licensing. Had the NRC examined these replacement steam generators, it would have uncovered significant modifications of the original design that led to their failure and the release of radioactive steam less than two years after installation.
This lack of adequate oversight not only poses a threat to our communities, but has come at a cost of $670.8 million. We, as ratepayers, have been forced to foot the bill for these critically-flawed steam generators. Although Southern California Edison also shares in the responsibility to adequately maintain and evaluate the safety of the San Onofre plant, it is your responsibility to hold them accountable.
We are deeply concerned about the lack of transparency and disregard for safety on the part of Southern California Edison and that the NRC has failed in its responsibility to ensure the safety of San Onofre. We find it unacceptable that we have been living with this unknown threat for decades.
We look forward to your timely response to our concerns.
Yours sincerely,
Gene Stone
Founder ROSE
Residents Organized for a Safe Environment.
Founder ROSE
Residents Organized for a Safe Environment.
Donna Gilmore
Communications director
San Onofre Safety
Communications director
San Onofre Safety
Gary Headrick,
Founder
San Clemente Green
Founder
San Clemente Green
