Why we went to Federal Court over San Onofre
By: Joe Holtzman
What We Know
The four new steam generators cost $138,000,000.1 (Demand for Arbitration p. 49) Their tube wear was caused by (i) insufficient in-plane tube support and (ii) high localized thermal-hydraulic conditions. 2 All four steam generators were permanently removed from service after less than two years of operation. (Demand for Arbitration p. 49)
The San Onofre nuclear power station consists of two “Units” – Unit 2 and Unit 3 – each of which is powered by a Pressurized Water Reactor (“PWR”). In a PWR, two main fluid systems work together to produce electric power: (1) the Reactor Coolant, or “primary,” system and (2) the Main Steam, or “secondary,” system. The primary system in each Unit contains a nuclear reactor that heats water to about 600 degrees Fahrenheit. The heated, radioactive water is circulated under pressure through thousands of metal alloy tubes inside two steam generators per Unit. The hot water heats the tubes, and the tubes transfer heat to non-radioactive water surrounding the tubes in the secondary system. That water, in turn, becomes high-pressure steam that flows up and through the tube bundle and then is piped into a steam-driven turbine-generator, where electricity is generated. Figure 1 on the following page generally illustrates the relationship between the two systems” 3
What SCE Admits
SCE admits the following facts. Numerous assurances were made the design was adequate to prevent damaging tube vibration. In connection with the four steam generators SCE admits these facts:
a.A design review process was used that failed to catch or correct its thermal hydraulic and computer modeling errors;
b.Failed to consider the cumulative effects of the changes to its [new steam generator] design;
c.Designed supports that were inadequate for the actual operating thermal hydraulic conditions;
d.Did not adequately calculate all critical velocities;
e.Did not control all modes of vibration;
f.Failed to perform appropriate testing and validation;
g.Failed to maintain a quality assurance program that met the applicable requirements of Appendix B to 10 C.F.R. Part 50, 10 C.F.R. Part 21, and American Society of Mechanical Engineers Code Section III; and
h.Failed to verify, as required by NRC regulations, and applicable engineering codes, that its computer model outputs and inputs were correct, resulting in gross underestimation of thermal hydraulic conditions in the [new steam generators]. 4
What’s Left to Know
The former CPUC expert Dr. Budnitz reported to the CPUC what needs to be found out: (1) What errors led to the tube failures?; (2) At what stage were those errors made?; (3) Who made those errors?; (4) What might have been done, and by whom, and at what stage, to have averted those errors; (5) What arrangements in place elsewhere, technical or administrative or both that were successful in averting these errors somehow didn’t work adequately for the SONGS RSGs?
We need to know these facts because the steam generators’ failure will require utility customers to pay over 5,000,000,000 for electricity that the closed plant will not produce. In other words SCE will receive payment with a profit for errors SCE executives made. How could this happen?
SCE executives and no less than 17 engineers met and conferred about the replacement SCE. The relevant SCE documents need to be obtained, and the key witnesses deposed. A careful review needs to be made of the record which has includes the following. On 13 December 2004 SCE executives met with Mitsubishi Heavy Industries (MHI) in “to discuss project performance and progress.” (Minutes 13 December MHI, SCE Kobe Meeting) A joint SCE-MHI Design Review Committee met no less than 25 times between December 2004 and June 2005. 5 A joint SCE-MHI Anti-Vibration Bar (ATV) Committee met 8 times between 2005 and 2007. Early in the project, SCE and MHI formed an AVB Design Team with the goal of minimizing U-bend tube vibration and wear. (Root Cause Report p. 17) It was the AVB Design Team that recognized that the design for the new steam generators resulted in higher steam quality (void fraction) than previous designs and had considered making changes to the design to reduce the void. The AVB Design Team agreed not to implement them because, in part, making them could impede the ability to justify the RSG design under the provisions of 10 C.F.R. §50.59. (Root Cause Report p.22) Some of the AVB Design Team meetings were video conferences. 6 SCE also had 18 Executive Oversight Committee meetings between February 2005 and June 2009. 7
The CPUC decided it does not want to investigate who and how made the $5,000,000,000 Mistake of San Onofre. The CPUC decided to just make the utility customers pay. This outcome further shows the CPUC is an arm of SCE and the other utilities. The U.S. Department of Justice, unlike in the case of PG&E (indicated in San Francisco) has failed to investigate. The Attorney General intervened in the CPUC proceedings but failed to participate. This leaves utility customers in the dilemma of either accepting the financial burden of the $5,000,000,000 Mistake at San Onofre or taking action in Court themselves. We have opted for the latter course.
1 The CPUC gave SCE $680,000,000 of ratepayer funds to replace the old steam generators. (2005 CPUC Decision p. 2)
2 The “high localized thermal-hydraulic conditions” refers to high localized steam quality (void fraction), flow velocity, and hydro-dynamic pressure.
3 Demand for Arbitration pp. 10-11.
4 Demand for Arbitration pp. 10-11.