The Nuclear Regulatory Commission (NRC) has issued its final report investigating two units at the San Onofre Nuclear Generating Station, a nuclear power plant located on the Pacific coast of California, which have been shut down since January 2012 after a worker noticed a leak.

The findings of the NRC’s Augmented Inspection Team (AIT) state that “unless changes are made to the operation or configuration of the steam generators … excessive tube wear and accelerated wear [will continue].”

San Onofre is a pressurized water reactor. (The other type of reactor is a boiling water reactor.) The basic principle of how it works is simple: nuclear energy produces steam, the steam drives a turbine, the turbine powers a generator, the generator produces elecriticity.

The tubes under discussion conduct water through the generator to the turbine. They transfer heat and also act as a radiation barrier, keeping hot radioactive water on one side and hot non-radioactive steam on the other side. If they are not repaired, the plant runs the risk of further future leaks.

These findings confirm Friends of the Earth (FoE)’s report released last week, outlining that San Onofre’s steam generators are in worse shape than all comparable generators nation-wide.

Additionally, the FoE report argues that Edison installed the tubes without applying for a design change, as required by NRC regulations for parts that are not a “like for like” replacement.

In 2010 and 2011, Southern California Edison installed two new steam generators. NRC regulations stipulate that if parts are not “like for like” replacements, a more stringent design change review be conducted. Typically, the process requires an NRC review, a license amendment and a public hearing. This did not happen. As the FoE report argues, Edison installed the tubes without applying for a design change.

NRC’s report, by contrast, states “Southern California Edison provided the NRC with all the information required under existing regulations about proposed design changes to its steam generators prior to replacing them in 2010 and 2011.”

According to Arnie Gunderson of Fairewinds Associates and author of the FoE report, “The plant is outside of its design basis. Every power plant has a design. When you make major changes, there is a procedure. They are playing games with licensing. Southern California Edison should have said that they are making major changes.”

According to the FoE, the NRC was asleep at the wheel in not registering the fact that San Onofre did not make “like for like” exchanges, which led to the leak and the FoE to file a petition for an investigation, resulting in last week’s report. In their estimation, NRC oversight is lacking.

Edison argues that tubes in one unit suffered less degradation than in the other. The NRC report supports this statement.

Arnie Gundersen said “there is no difference between Unit 3 and Unit 2. Both reactors need major repairs.”

The FoE report recommends that both reactors should remain closed. According to Damon Moglen, Director of FoE’s Climate and Energy Program, “the damage and problems at these two generators are astronomical and off the charts.”

The NRC report also identifies 10 issues requiring follow-up and states that “the plant will not be permitted to restart until the licensee has developed a plan to prevent further steam generator tube degradation and the NRC independently verifies that it can be operated safely.”

The NRC intends to schedule a meeting to receive and respond to public questions.

Aside from the immediate concerns about the safety of the new steam generators and tubes, several other factors make the nuclear power plant dangerous.

The San Onofre Nuclear Power Plant rests on the Pacific Coast 60 miles south of Los Angeles and 45 miles north of San Diego, the second and eighth largest cities in the U.S. respectively. The nuclear power plant is within 50 miles of 8.5 million people.

Numerous nuclear power plants throughout the U.S. are located close to cities: Indian Point is 24 miles north of New York City; Pilgrim is 38 miles southeast of Boston; and Turkey Point is 20 miles south of Miami.

Last summer, an Associated Press investigation found that populations around nuclear power plants have grown four-fold since 1980, while safety planning is not keeping pace with this urban sprawl. According to the AP, the “evacuation zones have remained frozen at a 10 mile-radius from each plant since they were set in 1978.”

The San Onofre Nuclear Power Plant is also located on the Pacific Plate of the active San Andreas Faultline. A report conducted by the California Energy Commission in 2008 to assess the risk of damage to nuclear power plants due to seismic activity found that it was much higher than previously thought. In April, Southern California Edison announced that it would conduct a study of offshore faultlines near the plant together with Scripps Institution of Oceanography

Other nuclear power plants, too, are located in earthquake, tornado or hurricane-prone zones. For example, the Indian Point nuclear power plant in New York; and Diablo Canyon nuclear power plant, 100 miles north of Santa Barbara rest on fault-lines or active plates.

Moglen underscores that “the seismic risk is also a problem for the massive amounts of nuclear waste sitting at San Onofre in absolutely unsafe conditions.” According to Moglen, the amount of waste stored at San Onofre is higher than at most other nuclear power plants in the United States.

Additionally, in 2010, the California State Water Resources Control Board adopted a policy on the Use of Coastal Waters for Power Plant Cooling, which stipulates that coastal power plants must reduce the use of “once through cooling”, drawing water in for cooling and flushing it out, since drawing water in harms marine life and the consequences of pumping hot water and chemical components out on sea water, marine life and the public have not been established.

Shifting to a new water source would require the construction of a cooling tower. But San Onofre is flanked by the Pacific Ocean on the west and California Interstate Highway 5 on the east. So it remains unclear where this tower would be built.

According to a feasibility study conducted in 2009 for Edison by Enercon “no nuclear stations designed solely for once-through cooling have been converted to closed-loop cooling; any closed loop conversion design would be unprecedented and would present inherent uncertainties.”

Moreover, the report said “Retrofitting SONGS [San Onofre Nuclear Generating Station] with a closed-loop cooling system would be challenged with insuperable permitting obstacles, unparalleled – ‘one of a kind’ – engineering challenges, adverse environmental impacts likely greater than those imposed by once-through cooling and initial costs exceeding $3 billion.”

Furthermore, the San Onofre plants, commissioned in 1983 and 1984, are both due to expire in 2022. “Given the costs of repairs to ensure safety compliance after January’s leaks, the need for seismic upgrades, the cost of license renewals, which will undoubtedly total billions of dollars,” Moglen asks “what is the overall efficacy of continuing to use San Onofre, particularly given that cheaper and renewable energy alternatives, such as wind and solar, abound in Southern California?”

Currently, no one is arguing that it is time to open San Onofre again. It is dangerous and all the reports – NRC and FoE – say so. And if Los Angeles and San Diego area residents have been able to meet energy needs during the heat of summer, one of the hottest on record, without the nuclear power plants running, it might not be needed.

The California’s Public Utilities Commission is weighing whether to order Southern California Edison to shut San Onofre down , given the financial and environmental costs associated with getting it to safe standards and running again.

On March 11, 2012 over 200 people rallied in San Onofre to encourage authorities to keep the power plant closed.

Tina Gerhardt

Tina Gerhardt is a freelance journalist. Her work has appeared in Alternet, Grist, The Nation and The Progressive.