A report that surfaced Friday on the root causes of the downed Southern California nuclear generating plant has further put the plant majority owner-operator in a legal battle with Japan’s Mitsubishi Heavy Industries (MHI), the designer and installer of the plant’s failed new steam generators.

The report, released by the Nuclear Regulatory Commission (NRC), said that before ill-fated generators were installed officials at both Southern California Edison Co. (SCE) and MHI considered but rejected design changes, allegedly because they would require more time for regulatory review.

In reiterating that the utility owner/operator earlier disclosed the same causes as MHI outlined, SCE said that the Mitsubishi unit “repeatedly reassured” the operator at the San Onofre Nuclear Generating Station (Songs) of the “efficacy of its design.” SCE said in a prepared statement Friday that MHI advised its plant operators that the Songs steam generators did not require additional design changes or measures.

Late last month, top executives from the companies that own and operate the idle Songs indicated that the plant’s fate remains uncertain, along with the 2,200 MW associated with it, which puts uncertainty into the state’s summer energy plans (see Daily GPI, Feb. 28).

California state officials recently released an updated state energy report noting that after a decade of steady decline, natural gas demand in the state is forecast to grow annually, albeit slowly, during the next 10 to 15 years. Those projections could be accelerated by a prolonged Songs outage (see Daily GPI, March 5).

Edison International CEO Ted Craver has already disclosed that the cost of the Songs outage last year totaled $400 million, and work to get both units at Songs back in service could take up to five years. In the meantime, the cost of alternatives and who will pay for them is still unknown. Alternatives include more natural gas-fired power generation.

Natural gas in the electricity system will become more critical as the state pushes for 33% — and possibly as high as 40% renewables by the early 2020s — according to the 2012 Integrated Energy Policy Report update recently released by the California Energy Commission. With more intermittent sources, such as solar and wind, natural gas is needed more than ever to help maintain grid reliability.

The latest NRC report provides the most detailed picture yet of the flawed design written by MHI, which built the four massive generators installed at Songs for nearly $800 million.

SCE continues to spar with MHI over the design flaws and the Japanese company’s proposed cap on its responsibility for bearing the costs of the repairs. SCE on Friday continued to stressed that Songs is the largest source of baseload electric generation and voltage support in the Southern California region, and it called the facility “a critical asset in meeting California’s summer electricity and clean energy needs.”

Sempra Energy’s San Diego Gas and Electric Co. holds a 20% interest in the nuclear plant and thus has been responsible for 20% of the costs incurred during the now 13-month-long outage.

©Copyright 2013Intelligence Press Inc. All rights reserved. The preceding news reportmay not be republished or redistributed, in whole or in part, in anyform, without prior written consent of Intelligence Press, Inc.