ML13169A374

LTR-13-0534 Vinod Arora E-mail San Onofre Nuclear Generating Station

ML13169A374
Person / Time
Site:	San Onofre
Issue date:	06/11/2013
From:	Arora V Public Commenter
To:	Macfarlane A NRC/Chairman
References
LTR-13-0534
Download: ML13169A374 (3)

Text

Joosten, Sandy From: Vinod Arora <vinnie48in@gmail.com>

Sent: Tuesday, June 11, 2013 2:09 PM To: CHAIRMAN Resource; CMRAPOSTOLAKIS Resource; CMRMAGWOOD Resource; CMROSTENDORFF Resource; CMRSVINICKI Resource; Dorman, Dan; Leeds, Eric; R4ALLEGATION Resource; Lantz, Ryan; Hall, Randy; Benney, Brian; Howell, Art; Borchardt, Bill

Subject:

San Onofre Sad Saga Continued- NRC/SCE/MHI/Public Education Series SONGS Steam Generator Degradation Root Cause- Lack of Critical Questioning & Investigative Attitude, Inadequate review of Academic Research Papers, Questionable Testing of AVBs, Lack of Team work Between MHI & SCE, Negligence, Negative Safety Conscious Work Environment and Production Over Profits Most of the steam generators operate at void fractions below 98.5%, steam pressures > 900 psi and recirculation ratios >4. This ensures operation of the SG in the nucleate boiling regime (damping of hot SG tubes to prevent FE I), optimum operation of the SG performance and ensures the prevention of adverse effects of FEI (High Dry Steam, high fluid in-plane velocities, Film Boiling), flow-induced random vibrations and excessive dynamic pressures on tube-to-tube wear, tube-to-AVB!TSP wear and retainer bar-to-tube wear.

Along with numerous untested and unapproved design changes made under the false pretense of "like for like" replacement with "improvements" to avoid a lengthy NRC 10CFR 50.90 Review and Public Hearings, SCE designed and MHI fabricated 21st Century Safest and Innovative Replacement Steam Generators were operated outside the above operational parameters to maximize both the SG thermal output and profits. The public has grown jaundiced listening to the explanations of what went wrong at the utility's San Onofre Generating Station, or SONGS. A radiation leak ignited the ensuing firestorm. But questions soon followed as to whether the utility knew from the onset that it had installed problematic equipment and whether it had purposefully sidestepped the regulatory process. "If we could roll back the clock, we would do it differently, says Edison International EIX-0.13%'s Chief Executive Ted Craver, who adds that a detailed public review would not have foreseen the issues that caused the shutdown of SONGS.

Specifically, the utility's then-plant Chief Nuclear Officer Dwight Nunn penned two letters in 2004 and 2005 to its vendor, Mitsubishi Heavy Industries. Disruptive vibrations were occurring and causing tubes to prematurely wear out. That could cause radiation to leak, Dwight Nunn had said, which is exactly what happened to one of the reactors in January 2012. The company decided to temporarily shut down both units at that time.

The utility is under sharp attack because it has never wavered from its position -that it had no knowledge of the problems tied to its new steam generators until last year. Critics are also pouncing on Southern California Edison, saying that it refused to disclose the letters and its troubles so as to avoid time consuming and costly public hearings on the subject.

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The utility and its vendor are arguing that the kind of vibrations that occurred in the trial phases in 2004 are different from those that caused the tubes to leak in 2012. Southern California Edison is furthermore saying that the rules do not require it to undergo public hearings if the replacement generators are essentially the same "form, fit and function" as the previous ones. As a Nuclear Plant Designer & Operator SCE and NEI Qualified "US Nuclear Plant Designer" MHI should have been able to foresee the destructive end result of their wrong actions, but they ignored the warnings from Dwight .

Nunn, SCE/MHI AVB Team and forgot the elementary rules of the heat transfer in their madness to build the dream radiation steaming generators and rush to maximize the profits. SCE/MHI should have known the adverse consequences of these change and now if they claim. the did n9t. knew or it did not make a difference, it presents a e challenge for NRC and Public.

Regardless, nuclear energy experts are telling that the episode at SONGS does not boost confidence in the industry or its quality assurance processes. As a practical matter, the industry's leading voice, the Nuclear Energy Institute, has remained mum on the subject, as has its leading utilities: Exelon EXC +0.41% Corp., Duke Energy, Dominion Resources and Entergy Corp.

While Chairman Craver says that the new generators were installed to help end the existing tube corrosion, they were still 24 tons heavier. They also had hundreds of additional tubes. Those two changes alone were enough to trigger hearings before the Nuclear Regulatory Commission, says former NRC Chair Gregory Jaczko, who led the agency from 2009 to 2012.

MHI Root Cause states, "Thus, not using ATHOS, which predicts higher void fractions than FIT-Ill at the time of design represented, at most, a missed opportunity to take further design steps, not directed at in-plane FEI, that might have resulted in a different design that might have avoided in-plane FEI. However, the AVB Design Team recognized that the design for the SONGS RSGs resulted in higher steam quality (void fraction) than previous designs and had considered making changes to the design to reduce the void fraction (e.g., using a larger downcomer, using larger flow slot design for the tube support plates, and even removing a TSP). But each of the considered changes had unacceptable consequences and the AVB Design Team agreed not to implement them.

Among the difficulties associated with the potential changes was the possibility that making them could impede the ability to justify the RSG design under the provisions of 10 C.F.R. §50.59. Thus, one cannot say that use of a different code than FIT-Ill would have prevented the occurrence of the in-plane FEI observed in the SONGs RSGs or that any feasible design changes arising from the use of a different code would have reduced the void fraction sufficiently to avoid tube-to-tube wear. For the same reason, an analysis of the cumulative effects of the design changes including the departures from the OSG's design and MHI's previously successful designs would not have resulted in a design change that directly addressed in-plane FEI."

We now know the adverse results of that SCE/MHI missed opportunity, destruction of a $1 Billion Dollars in Steam Generators and the Number 1 US Public Safety Concern/Nuclear Scandal, Controversy and Cover-up involving NRC, CPUC, SCE, MHI, Westinghouse, AREVA, lntertek and others. Dr. Pettigrew, the Worlds authority on fluid elastic instability and flow-induced vibrations told Dr. Macfarlane and the other NRC Commissioners that MHI's AVBs simply do not provide a positive restraint against FEI.

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1. Unit 3 Root Cause: High Void fractions of 99.6%, high steam flows (film boiling), higher thermal reactor power per RSG (RCS Flows, 76 Million lbs./hr, 1737 MWt plus), high in-plane fluid velocities (35-50 feet/sec), circulation ratios of 3.3, narrow tube to pitch tube diameter, excessive number of 9,727 tubes, extremely tall tubes (average length of heated tube increased by 50 inches, equivalent to the addition of -650 tubes), 116,000 square feet of tube heat transfer area (increased from 104,000 in the OSGs), lack of positive in-plane restraints, steam generator operation at too low a pressure (833 psi), insufficient tube-to-AVB contact forces(< 1N per MHI) and loose supports (larger tube-to-AVB Gaps, Based on SCE Incomplete ECT Results) caused FEI, Flow-Induced Random Vibrations and Mitsubishi Flowering Effect in Unit 3 @1 00%RTP. The flow regime in Unit 3 changed from nucleate boiling to film boiling because the Unit 3 RSG heat transfer coefficient was exceeded and the change was attributed to more than 5MWt of SG output in Unit 3 in 4% of the SG U-tube bundle high region of wear on the hot-leg side due to higher RCS flows and lower SG Pressure Operation in Unit 3 RSGs.

2. Unit 2 Root Cause- Moderate Void fractions of (98-98.9%), lower steam flows compared to Unit 3 (nucleate boiling), lower thermal reactor power per RSG compared to Unit 3 (RCS Flows, 74 Million lbs./hr, 1727 MWt plus), high out of-plane fluid velocities (25 feet/sec), circulation ratios of 3.3, narrow tube to pitch tube diameter, excessive number of 9,727 tubes, extremely tall tubes (average length of heated tube increased by 50 inches, equivalent to the addition of -650 tubes), 116,000 square feet of tube heat transfer area, lack of in-plane restraints, steam generator operation at 942 psi (consistent with NRC AIT Report and SONGS SGM procedure) and questionable tube-to-AVB contact forces(-

2N per MHI) and better supports (smaller tube-to-AVB Gaps, Based on SCE Incomplete ECT Results) caused Flow-Induced Random Vibrations and Mitsubishi Flowering Effect in Unit 2

@100%RTP.

3. Even though SCE, MHI and AREVA claim that operating and thermal-hydraulic conditions were the same in both units, Unit 2 did not experience tube-to-tube wear because of lower reactor thermal power and higher steam generator pressure operation and NOT double tube-to-AVB contact forces and better supports because of inadvertent accidental Unit 2 AVB design as explained by SCE and MHI. FEI did not occur in Unit 2, which is consistent with Westinghouse report. The NRC AIT Report noted in error and without thorough investigation that the operational differences did not have any effect on the degradation mechanisms between Units 2 & 3.

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