2015 - 04 - 16 New Seismic Contentions Filed

MOTHERS FOR PEACE CONTENDS DIABLO CANYON IS NOT PROTECTED AGAINST REASONABLY FORESEEABLE SEVERE EARTHQUAKES AND FLOODS. Group urges U.S. Nuclear Regulatory Commission (NRC) to refuse 20-year license term extension for lack of risk analysis and environmental protection measures.


On April 15, 2015, San Luis Obispo Mothers for Peace filed two new contentions with the Nuclear Regulatory Commission (NRC) in opposition to Pacific Gas and Electric Company’s (PG&E’s) application for 20-year renewal of its operating license term for the twin Diablo Canyon nuclear reactors.

The contentions assert that PG&E has failed to comply with environmental laws requiring it to propose measures to lessen the impacts of severe Fukushima-like earthquakes and floods at Diablo Canyon.  SLOMFP contends that PG&E’s program to protect against earthquake impacts is weak because PG&E has understated severe earthquakes risks.  PG&E’s program for protecting against severe flooding events is also weak because it ignores PG&E’s own post-Fukushima study showing that heavy rainstorms may flood safety equipment.

These contentions were filed by San Luis Obispo Mothers for Peace attorney Diane Curran on April 15, 2015, and are available at http://mothersforpeace.org/data/2015/2015-04-15-new-contention-regarding-adequacy-of-severe-accident-mitigation-alternatives-analysis

These two new contentions are in addition to the two environmental contentions filed on April 6, 2015, which assert that it is not necessary to renew Diablo Canyon’s license because alternative energy sources are plentiful. The press release about those contentions, including a link to the legal filing, may be viewed at http://mothersforpeace.org/data/2015/2015-04-07-press-release-new-environmental-contentions-filed

This wave of new legal challenges by Mothers for Peace was precipitated by the recent release by PG&E of several studies:(1) PG&E’s amendment of its Environmental Report in March 2015, (2) PG&E’s submission to NRC of a new post-Fukushima seismic hazards assessment, and (3) PG&E’s post-Fukushima study of flooding risks

Mothers for Peace Spokesperson Jane Swanson asserts that “PG&E has been trying to rationalize away the dangers presented by the earthquake faults surrounding Diablo Canyon ever since the Hosgri Fault was acknowledged in 1972. PG&E appears to think that ignoring problems or using unproven and outdated methods will make the problems go away, and the NRC has been all too cooperative in supporting that delusion. Mothers for Peace is determined to put a stop to this game of charades.”

The group hopes to win a hearing on the adequacy of PG&E’s environmental risk mitigation program for the proposed license renewal term.


San Luis Obispo Mothers for Peace opposes PG&E’s application for 20-year operating license extensions for Diablo Canyon Units 1 and 2, with current licenses due to expire in  2024 and 2025.  In November of 2009, PG&E applied to NRC to extend Diablo Canyon operations until 2044 and 2045.

The Diablo Canyon facility includes two nuclear reactors and the storage of all the high-level radioactive wastes generated by those reactors since 1984. Currently, most of the used fuel (which is more radioactive than the fuel in the reactors) is stored in over-crowded pools. Approximately a third of the spent fuel has been transferred to dry casks.

In 2010, Mothers for Peace won a hearing before the NRC’s Atomic Safety and Licensing Board on the question of whether PG&E had given adequate consideration to the earthquake risks posed by the recently-discovered Shoreline Fault in its program for mitigation of severe accident impacts.  The NRC put Mothers for Peace’s seismic challenge on hold for several years while PG&E completed seismic studies required by the State of California. The NRC has tentatively scheduled evidentiary hearings on the seismic contention for  some time in 2016. The new contentions filed by Mothers for Peace on April 15 would broaden the scope of the hearing.