Union of Concerned Scientists questions restart of San Onofre Unit 2 nuclear reactor

Union of Concerned Scientists has serious concerns about Southern California Edison’s (SCE) restart plans for San Onofre Unit 2. In a 10/12/2012 letter submitted to the Nuclear Regulatory Commission (NRC), David Lochbaum, Director, Nuclear Safety Project, identified the following issues:

  1. Unit 2 replacement steam generator 2SG89 has significantly more wear indications per number of supports than does [Unit 2] replacement steam generator 2SG88. Until the reason for this marked difference between the wear degradation for the Unit 2 replacement steam generators is understood, the operational assessment performed for future operation is suspect. [See graph in Lochbaum letter].
  2. Since all four replacement steam generators came from the same manufacturer, were of the same design, made of the same materials, assembled using the same procedures, and operated under nearly identical conditions in twin reactors, the reason for this marked difference is unclear… [the] explanation is not well documented and therefore appears to be more convenient than factual.
  3. The document states that the owner will “administratively limit Unit 2 to 70% reactor power prior to a mid-cycle” outage to inspect the replacement steam generators. What are the legal consequences if the reactor power were to increase to 75%, 85% or 100% power? The NRC has licensed San Onofre Unit 2 to operate at 100% power. What would legally prevent the owner from restarting Unit 2 and increasing its output to the NRC licensed limit? The NRC’s enforcement program includes sanctions when its regulations are violated, but nothing for broken promises. If the NRC agrees that reactor operation at less than 100 percent power is warranted, it should enforce that reduction with an order or comparable legally-enforceable document.
  4. Table 8-1 of Enclosure 2 and its accompanying text attempt to explain how operating Unit 2 at 70% power will prevent the tube-to-tube wear (TTW) experienced on Unit 3 by comparing it to an anonymous reactor (called Plant A). ..reliance on one suspect data point (Plant A) is hardly solid justification for operation and 70% power being acceptable.
  5. There is no justification in this 80-plus page document for an operating duration of 150 days.
  6. … there are no legal means compelling the plant’s owner to shut down Unit 2 after 150 days of operation at or above 15% power.
  7. ...a temporary nitrogen-16 radiation detection system will be installed prior to the Unit 2 startup. However, there is no commitment to use it after startup, or to keep it in service should it stop functioning. The detection system is proposed as a defense-in-depth measure, but there is no assurance it will be operated.
  8. Attachment 6 to Enclosure 2 has proprietary information redacted. Section 1.4 of Enclosure 2 states that the owner used AREVA, Westinghouse Electric Company LLC, and Intertek/APTECH to review the operational assessment. At least one of these companies manufactures replacement steam generators and would therefore be a competitor to Mitsubishi Heavy Industries (MHI), which made the replacement steam generators for San Onofre. If the owner did not withhold the proprietary information from MHI’s competitors, why withhold it at all? If SCE did withhold the proprietary information from these reviewers, what is the value of their independent, but limited, review?

Nuclear Regulatory Commission (NRC) Confirmatory Action Letter (CAL) dated March 27, 2012, (ADAMS Accession No. ML12087A323). required the owner of the San Onofre nuclear plant to submit to the NRC its report on the root cause of degradation to the replacement steam generator tubes and to keep both reactors shut down until the NRC reviewed and agreed with the root cause determination.

SCE submitted an 80-plus page report dated October 3, 2012, describing the causes of the steam generator tube degradation and proposing compensatory measures if the NRC permits Unit 2 to restart.

However, Lockbaum questions whether the root cause has been properly identified.  He states

“…when reactor safety problems rise to the point where an owner must submit a formal root cause report to the NRC, it is a prudent public health practice that these reports be submitted prior to restarting the affected reactors. If the cause of the degradation has not been properly identified, then the solutions applied to the wrong cause may not adequately protect the public.”

The issues raised by Lockbaum must be address by the NRC.  Restarting a broken nuclear reactor is unacceptable.

About Donna Gilmore

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10 Responses to Union of Concerned Scientists questions restart of San Onofre Unit 2 nuclear reactor

  1. Pingback: Union of Concerned Scientists questions restart of San Onofre Unit 2 nuclear reactor « Fukushima 311 Watchdogs

  2. CaptD says:

    Salute, nice article!

    For more technical info: http://decommission.sanonofre.com/
    Read the latest:
    Update 10-14-12, SCE’s Replacement Steam Generator $680 Million Debacle

  3. CaptD says:

    Open Letter to Southern California Ratepayers

    The 1.2 Billion Dollar Question: Do we want to RISK Southern California Edison (SCE) restarting their heavily damaged San Onofre Nuclear #2 Reactor?


    The International Atomic Energy Association (IAEA) ranks nuclear accidents by Levels between 1 and 7, with the number increasing with the scale of the accident. For example, a level one is a minor nuclear event, while a level seven is the highest rating and signifies a major nuclear accident.)

    On February 9th, 1991, a leak of 55 tons of radioactive primary coolant occurred due to the failure of just one tube in a steam generator (SG) built by Mitsubishi Heavy Industry (MHI) in the No. 2 pressurized water reactor at the Mihama nuclear power station in Japan, caused wide spread public alarm due to that unsafe nuclear reactor.

    Mihama was ranked a level three nuclear disaster, the first ever in Japan.
    Three Mile Island was ranked a level five nuclear disaster (loss of coolant).
    Chernobyl was ranked a level seven nuclear disaster (loss of coolant).
    Fukushima Daiichi was ranked a level seven nuclear disaster (loss of coolant).

    Current situation of SORE (San Onofre Reactor Emergency):

    On January 31, 2012, one tube leak was discovered at San Onofre SONGS Unit 3 that resulted in some radioactivity being released into the atmosphere. Upon further testing, eight more tubes in the steam generators (SG) failed pressure testing. What this means is that the SONGS accident could have been many times worse than Mihama Nuclear Disaster, especially if both reactors were online and we had a big quake, so all of us in Southern California were just plain lucky that day!

    These almost new steam generators (SG) were just built by Mitsubishi Heavy Industry (MHI) to specific design specifications supplied and approved by Southern California Edison (SCE) engineers, without any additional Nuclear Regulatory Commission Design review because they were told that the replacement SG’s were just like the ones they were replacing, which was not the case! In reality, they were significant changes made to the design by SCE, which has caused the tubes to start to fail.

    The total tube damage at SORE (San Onofre Reactor Emergency) to date:

    1. On Unit 3 steam generators (SG):
    8.5% of the tubes (1657 out of 19454 tubes on both SGs) showed
    wear of greater than 10% through-wall indications.
    8 tubes failed in-situ pressure testing
    SCE completed extensive plugging and selective staking of 807
    tubes and found 10,284 wear indications on 1806 tubes.

    2. On Unit 2 steam generators (SG):
    5.2 % of the tubes (1009 out of 19454 tubes on both SGs) showed
    wear greater than 10% through-wall indication.
    The total plugging for Unit 2 was 510 (205 tubes in 2E088 and 305 in
    2E089) plus they found 4721 wear indications on 1,595 tubes.

    Decision time:

    If we allow SONGS Unit 2 to be restarted without our approval, any problems with or without an earthquake or main steam line break could cause an unknown number of already damaged and or stressed/weakened tubes in their poorly designed Replacement Steam Generators to rupture like just ONE tube did in Mihama, Japan and cause a Level 3 nuclear accident! San Onofre already has more tubes that have failed testing than any other reactor facility in the USA! These failures could even cause a potential reactor meltdown of SONGS Unit 2 resulting in a Fukushima Daiichi Nuclear or Chernobyl level seven disaster here in Southern California.

    Are you willing to live with that threat?

    If not, write to all your Congressman and or City Councilman, then join the protest against the Restart of SONGS Unit 2. After all, we are the ones paying for Southern California Edison (SCE), the Nuclear Regulatory Commission (NRC), the California Public Utilities Commission (CPUC) Officials and all the other Elected Politicians in the Country to protect us.

    If a Nuclear Disaster were to happen, if your property became radioactive (and basically worthless) where would you and your family be relocated to; and for how long would you have to stay there? As an example in Japan, a year and a half after Fukushima, there are still many hundreds of thousands of nuclear refugees still living in camps, unable to return to their homes because of radiation!

    California now has a 40% power surplus without San Onofre (or even Diablo Canyon) nuclear power plants (per the CPUC), with more risk-free solar capacity being added daily, so it just does not make any sense to gamble our future restarting Unit 2, just to save SCE shareholders some big bucks!

    Now is time to decommission San Onofre.

  4. CaptD says:


    Posted Oct. 16, 2012

    WASHINGTON, D.C. — The Nuclear Regulatory Commission’s continued refusal
    to consider a legally binding hearing on the future of the San Onofre
    nuclear plant has prompted Friends of the Earth to accuse the agency of
    failing to protect the public and of failing to follow its own rules and

    More than three months have passed since Friends of the Earth petitioned
    the NRC
    a legally binding hearing on the future of the crippled plant. In that
    time, the NRC has failed to even schedule a discussion of the petition. Now
    that Southern California Edison has submitted a plan to restart one of San
    Onofre’s reactors, Friends of the Earth is reiterating its request that the
    NRC begin a license amendment process to determine if San Onofre is safe to
    operate and is asking for an emergency stay to keep the plant closed in the

    In a letter to the

  5. Pingback: 10/25/2012 Irvine CPUC meeting – San Onofre on agenda | San Onofre Safety

  6. Pingback: NRC launches two proceedings about San Onofre’s future | San Onofre Safety

  7. Pingback: NRC canceled Nov 16 meeting but our message remains the same | Residents Organized for a Safe Environment

  8. Pingback: 1/8/2013 San Francisco CPUC prehearing conference on San Onofre Nuclear Power Plant | San Onofre Safety

  9. Pingback: San Diego Loves Green – Ratepayer and Public Interest Advocates Propose Formal Review of Cost to Replace San Onofre Steam Generators

  10. Pingback: Ratepayer and Public Interest Advocates Propose Formal Review of Cost to Replace San Onofre Steam Generators | San Diego Loves Green

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