SONGS Next Steps: The Move to Decommission

Victor Dricks
Senior Public Affairs Officer
Region IV

songsdropquoteSouthern California Edison Co. has sent the NRC letters certifying that it has permanently removed all of the fuel from its Unit 2 and 3 reactors at the San Onofre nuclear power plant in Southern California. These letters are the company’s second certification – following its June 12 notification that it had permanently ceased operation – and officially move San Onofre into the decommissioning process.

Under NRC rules, Edison’s letters permanently end the utility’s authorization to operate those reactors. In addition, the NRC has notified Edison that the Confirmatory Action Letter of March 27, 2012, is no longer applicable. The NRC has terminated its inspection and review of all of the activities specified in the letter, which set forth terms and conditions necessary to prepare the reactors for restart.

Greg Warnick, the NRC’s Senior Resident Inspector, in the near term will continue onsite inspections of activities associated with decommissioning, site staffing levels and plant security and safety. The facility will remain subject to NRC oversight thoughout the decommissioning process.

Meanwhile, we expect Edison to request several changes to both units’ licenses to reflect the transition to decommissioning, while still meeting the relevant requirements for safety, security and emergency preparedness now that San Onofre is no longer operating. Planning is currently underway for an orderly transfer of regulatory responsibility from the NRC’s Office of Nuclear Reactor Regulation to the NRC’s Office of Federal and State Materials and Environmental Management Programs, which oversees decommissioning nuclear plants.

Planning is also underway for the NRC to hold a public meeting in the vicinity of the plant in early fall to explain the decommissioning process.

Edison is now drafting its decommissioning plan, which they must submit to the NRC by June 12, 2015, two years after they formally shut down the plant.

Author: Moderator

Public Affairs Officer for the U.S. Nuclear Regulatory Commission

4 thoughts on “SONGS Next Steps: The Move to Decommission”


    After 30 months of San Onofre Unit 3 RSGS in-plane FEI “No Stones Turned, HAZOP and Nuclear Oversight GAP” investigations, AVP Arora International with the expert assistance of several anonymous California Professional Engineers and International two-phase, heat transfer, and fluid international experts with Ph.D. In Chemical Engineering, in-depth review of all the San Onofre Reports/Academic Research/NRC licensed In-plane RSGs, Industry Operating Experience and Basic Heat Transfer Calculations, concludes the following:

    1. NRC “Enlightening” SG Training Manual states, “If circulation is inadequate, the heat transfer surfaces tend to become blanketed with steam rather than continuously wetted by a steam/water mixture.” San Onofre Unit 3 RSGs in-plane FEI occurred because SCE was operating Unit 3 steam generators in violation of SCE’s RSGs 10 CFR 50.59, SCE’s RSGs Conformed Specifications and SCE’s RSGs Design/Functional Testing Parameters and the tube surfaces became blanketed with dry steam (contains no free water to cool the tubes and creates peak steam velocities) due to inadequate circulation ratios. San Onofre Unit 2 RSGs experienced uncontrolled out-of-plane vibrations, but did not experience in-plane FEI because SCE was operating Unit 2 steam generators consistent with SCE’s RSGs 10CFR 50.59, SCE’s RSGs Conformed Specifications and SCE’s RSGs Functional Testing Parameters and the tube surfaces were wetted by a steam/water mixture (nucleate boiling) despite under par circulation ratios. Unit 2 Analysis is consistent with Westinghouse Analysis,

    2. The untested & unanalyzed design/operational changes between OSGs and RSGs and the operational differences between San Onofre Units 2 & 3 RSGs (Steam pressures, primary temperatures and circulation ratios) are the Fundamental Root Cause for in-plane FEI, localized film boiling, tube-to-tube contact and unprecedented tube-to-tube wear, tube leak and failures of hundreds of tubes in Unit 3 RSGs in 11 months or days of adverse operation,

    3. The untested, un-analyzed and non-conforming design/operational changes between OSGs and RSGs in violation of federal regulations and SCE’s design review procedures as a result of SCE’s defective 10 CFR 50.50 (Equivalency) Evaluations and SCE/MHI Inadequate Design Reviews are the Contributing Root Cause for increased (uncontrolled) out-of-plane vibrations and tube-to-AVB/TSP wear in both Units 2 & 3 RSGs,

    4. The ironic manufacturing improvements between Units 2 & 3 and computer modelling errors cited by SCE/NRC AIT Team/MHI were not responsible for the in-plane FEI in Unit 3 RSGs and differences in damages between Units 2 and 3 RSGs. If that was the case, Unit 2 RSGs should have also experienced in-plane in FEI, but they did not, and

    5. The low tube-to-AVB contact force, AVB twist & dent/signals theory was a convenient reason invented by MHI and endorsed by NRC/SCE to explain the convenient reasons for occurrence of in-plane FEI in Unit 3 RSGs, difference in damages between Unit 2 & 3 RSGs and a failed attempt to restart Unit 2 on an experimental basis. None of these parties discussed the contribution of trefoil broached TSPs vs. egg-crate lattice grid supports causing high pressure losses and low circulation ratios (documented in several studies/NRC evaluations by Westinghouse & BW&I Canada) as a major contributor to tube-to-AVB/TSP damage and in-plane FEI in Unit 3 RSGs. Therefore, the results of SCE, MHI & NRC AIT/Inspection/NRC San Onofre Lessons Learnt Reports & Root Cause Analyses, AVB Testing & Tube Inspections based on un-validated and un-researched analytical assumptions are considered to be technically unsound and significantly flawed.


    After closure of all the failed and significantly flawed San Onofre replacement steam generators investigations due to the successful efforts of SCE Officers & Lobbyists, NRC is finally waking up and trying to catch up on its catastrophic mistakes in failure to identify the true root cause of in-plane FEI in SONGS Unit 3 RSGs. Ironically, in a new secret effort, a NRC/EPRI/Nuclear Industry Steam Generator Task Force has approved funding in February 2015 for investigation and testing (2015 – 2017) to understand the causes for the onset of in plane fluid elastic instability (FEI) in San Onofre Unit 3 Replacement Steam Generators (RSG). The industry indicated that it could not do a formal “SONGS lessons learned evaluation” since much of the information is not publicly available (i.e., proprietary); however, they did indicate that testing regarding the major cause of degradation (i.e., in-plane fluid-elastic instability) was warranted and was being pursued. Prediction of the final solution is difficult. Utilities may be able to use the results to avoid operating their SG in these regimes. SG designers may be able to understand their margins in operating SGs and avoid it with new designs. This is a learning effort that will be adjusted or stopped as each phase is completed, depending on the results. The goal of three years testing to measure vibration is from 0 to 98% void fractions up to and slightly beyond critical flows. The goal of the three years testing is to understand what leads to the onset of in-plane fluid elastic instability. It is ironic that NRC after 3 years of investigations still does not understand the causes of San Onofre replacement steam generator failures.

    Based on SCE statements and MHI AVB testing experience, steam generators full scale testing is not feasible at 100% power conditions to reproduce and duplicate the results of adverse and unprecedented conditions (dry steam, 99.6% void fraction with no free water and peak steam velocities of 35 feet/second) experienced by San Onofre Unit 3 RSGs. Manufacturers like Westinghouse & B&WI Canada have designed large steam generators successfully to prevent in-plane FEI for decades, but have not performed full scale testing of steam generators with dry steam (99.6% void fraction with no free water). San Onofre Unit 3 were the only steam generators in the world, which experienced dry steam (99.6% void fraction with no free water). Dr. Michel Pettigrew, the number one expert in the world on fluid elastic instability and flow induced vibrations and conducting research and testing on this subject for the last 40 years told the NRC Commissioners, “We’ve been trying to model these phenomena for quite a number of years, and I guess we’ve made some progress, but so far we haven’t been able to predict what we have seen in the lab, you know, within plus or minus 10, 20 percent, and we’re out by a factor of 50 percent or more. And it’s particularly difficult in two-phase flow, because in two-phase flow, you have an extra parameter, which is void fraction or steam quality, if you like.”

    The key to success from SONGS Lessons Learnt for preventing in-plane FEI in existing/new steam generators lies in analyzing and learning from the SCE held data for Units 2 & 3 cycle 16 operational data recorded in San Onofre Control Room Operator/Electronic Logs and plant computer system systems and apply those lessons in the design stage. NRC Chairman, CPUC President, Public Organizations, Consumer Advocates, Attorneys, CPUC President & News Media pressure is required for SCE to release San Onofre Units 2 & 3 RSGs Operational Data without further delay for assurance of Nuclear Safety for American Public from potential nuclear accidents due to design & operational defects in existing and new US steam generators.


    1. A San Onofre Root Cause Guru Reluctantly identified in June 2012 that San Onofre Unit 3 RSGs in-plane FEI was caused by pressure differences between the 2 Units (He participated in both San Onofre Root Cause Evaluations for Units 2 & 3)

    2. NRC Independent Consultant stated in July 2012, “What is clear from reviewing inspection data for the steam generators is that wear for both Units 2 and 3 steam generators occurred in the same localized region of the tube bundle, which suggests a common thermal-hydraulic root cause.”

    3. NRC AIT Team identified in July 2012 that Unit 3 were operating at higher temperatures than Unit 2.

    4. Union of Concerned Scientists, Director, Nuclear Safety Project, David Lochbaum in an email to NRC stated, “Both before and after SCE’s decision to permanently retire San Onofre Units 2 and 3, UCS has received inquiries from staff members for local, state, and federal officials, from citizens, and from reporters as to the root cause of the steam generator tube degradation. I have reviewed the reports issued by SCE, MHI, and NRC on the matter. To be honest, none have yet seemed to provide compelling, defensible identification of the real root cause(s). I expressed some of the reasons why the reports seems inadequate in a letter in 2012 to the NRC Region IV Administrator. The minor manufacturing tolerance differences seem some convenient than compelling. Actual differences in operating conditions (e.g., RCS temperature and pressure) seem to offer more likely causal factors.

    5. Mitsubishi’s AVB testing and repair plans were rejected by SCE in 2013 because NRC would have not approved the license of San Onofre new in-plane FEI replacement steam generator based on the MHI AVB mock-up testing. Based on Mitsubishi’s ( US website statements, NRC Independent Consultant’s Findings and Dr. Pettigrew’s comments to NRC Commissioners, it is concluded that the existing ATHOS Computer Programs developed by EPRI/Industry are not capable of predicting the peak steam radial velocities and localized film boiling conditions (dry steam with no free water) in existing US nuclear steam generators.

    6. NRC ASLB Three Judges Unanimous Ruling, May 2013, Page 32, “SCE and its contractors have evaluated the in-plane tube-to-tube wear due to fluid elastic instability and have developed a theory to explain its occurrence and to predict how it can be avoided. We conclude that until the tube degradation mechanism is fully understood, until reasonable assurance of safe operation of the replacement steam generators is demonstrated, and until there has been a rigorous NRC Staff review appropriate for a licensing action, the operation of Unit 2 would be outside the scope of its operating license because the replacement steam generator design must be considered to be inconsistent with the steam generator design specifications assumed in the FSAR and supporting analysis. There is a dearth of applicable experiential data available for in-plane vibrational motion. MHI states that incident to the design of the SONGS replacement steam generators, “only out-of-plane vibration of the [steam generator] U-tubes was evaluated.” Please CE/Westinghouse (NRC licensed) and BW&I Canada have been designing large steam generators with high steam flows using lattice grid tube supports, anti-vibration bars and high circulations ratios to prevent in-plane FEI in these steam generators for decades prior to the design/fabrication/installation of San Onofre RSGs.

  2. In the case of San Onofre is clear NRC staff lost and are poor losers. Rather than play by the rule of law (Case Law) they want to “vacate” or erase this loss from case law and act like outside of San Onofre nothing has changed. If the NRC commission can ignore or even thinks they can ignore any “judicial practice” including the “United States Supreme Court” then they are a rouge government organization in need of overhaul.

  3. Attorney generals fight for public access in Nuclear issues
    The Attorney Generals of New York and Vermont have joined the fight against California’s San Onofre Nuclear power plant in an effort to stop federal regulators from erasing all record of a judicial ruling that the public has a right to intervene before major amendments are granted to an operating license.

    “The Commission has stated that it is not bound by judicial practice, including that of the United States Supreme Court,” stated Schneiderman and Sorrell in a brief filed June 24 with the NRC challenging the staff request.

  4. SCE’s replacement steam generator debacle caused San Onofre to be shut down, now instead of being even fined by the NRC, they get to continue to milk ratepayers during the decommissioning process, which I’m sure they will stretch out as long as possible. This is yet another reason that we cannot afford using nuclear reactors any longer, they reward the Utilities instead of protecting the ratepayers if anything goes wrong.

    Also left unsaid is the 3/4 Billion Dollars that still remains to be collected for the estimated cost to decommission San Onofre, because it got shut down “early,” guess who will be stuck with that bill?

    The NRC needs to do much better!

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