Press Release regarding Diesel Generator Sensors

FOR IMMEDIATE RELEASE: May 31st,
2012

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.

 

“Within a matter of weeks the people
of Southern California will be asked to trust the assurances of Edison that
they can safely restart the San Onofre reactors. This latest revelation is one
more reason why there is no trust in Edison claims and why the NRC is seen as a
nuclear industry lapdog not capable of doing its job,” said Gene Stone of ROSE
in San Clemente.