ML20217A092

Lead Engineer Response to Demand for Info Re Yankee Atomic Electric Co

ML20217A092
Person / Time
Site:	Yankee Rowe
Issue date:	03/12/1998
From:	Robeck M BAKER & BOTTS
To:
Shared Package
ML20217A074	List: ML20217A070 ML20217A083 ML20217A092
References
EA-97-387, NUDOCS 9803240251
Download: ML20217A092 (5)

Text

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UNITED STATES NUCLEAR REGULATORY COMMISSION In the Matter of f f

YANKEE ATOMIC ELECTRIC COMPANY f f EA 97-387 and f e

DUKE ENGINEERING SERVICES f LEAD ENGINEER'S RESPONSE TO DEMAND FOR INFORMATION The individual identified in the above-captioned Demand for Information

(" Demand") as a Lead Engineer in the LOCA Group (the " Lead Engineer")2 respectfully submits this response' to the Demand:

The Lead Engineer considers the issues raised in the Demand to be very serious and has given them careful consideration. Duke Engineering & Services ("DE&S") responded to the Demand with several reports from multiple teams that investigated the various issues raised therein.

The Lead Engineer has reviewed the DE&S response and generally agrees with the assessments of This response should not be construed as consent to the Commission's authority to either exercisejurisdiction over the Lead Engineer or effectively penalize the Lead Engineer through issuance of the Demand. There are unresolved questions regarding the statutory authority of the Commission to exercise jurisdiction over an employee of an unlicensed vendor. Additionally, infonnally penalizing the Lead Engineer based on a legal standard that has not been adopted into the regulations raises constitutional questions. Although the Lead Engineer has chosen to respond to the Demand, she reserves all rights to assert any and all legal challenges to this proceeding.

2 As in the Demand, the individuals specifically identified in the Demand will be referred to as the " Lead Engineer" and the " Manager."

3 The Demand permi'.s but does not require that the Lead Engineer submit a response and she is not a party to this proceeding.

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her work and conclusions stated in the DE&S response. Notably, the DE&S response staten that the Lead Engineer did not disregard NRC requirements.

DE&S is not the only entity to have analyzed these issues. In the aftermath of the December 1995 anonymous allegation letter that was sent to the NRC, there have been numerous lengthy and thorough investigations by Yankee Atomic Electric Company ("YAEC") and Maine Yankee Atomic Power Company (" Maine Yankee"), by outside lawyers and technical experts, and by various agencies of the United States government, including the Justice Department. During the course of these investigations, the Lead Engineer always has cooperated and she has openly and honestly responded to questions to the best of her ability. While the Lead Engineer feels that there may be room for diiTerences of opinion conceming the technicaljudgments that she made regarding MYAPS SBLOCA analyses, there is no justification for attacking the Lead Engineer's honesty, integrity and credibility.

The Lead Engineer does not understand why the Demand identified the Lead Engineer and the Manager as the only responsible individuals participating in the events described therein. She was always open about the issues surrounding the RELAP5YA computer code and its application to Maine Yankee Atomic Power Station ("MYAPS"). People with more licensing experience and decision-making authority than the Lead Engineer knew the essential facts regarding RELAP5YA and its application to MYAPS and concurred with the results of the analysis. Thus, the decision to identify the Lead Engineer as one of only two responsible individuals appears ill-informed. i Finally, the Lead Engineer offers the follow'r.g smnmary response to the allegations in the Demand as she understands them to relate to her:

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• Allegation Ill.A: The Lead Engineer carelessly disregarded NRC requirements because she ca'used Maine Yankee to use an evaluation model that could not calculate ECCS performance between break sizes of 0 35ft2 and at least 0.60ft.2 Response: Contrary to carelessly disregarding NRC requirements, the Lead Engineer took actions that she intended to and believed would ensure compliance with NRC requirements.

Believing that the limiting small break had been identified and bounded by the results presented in YAEC-1868, the Lead Engineer did not believe additional cases were required.

Although RELAP5YA did not predict a smooth reduction in temperatures after SIT actuation, an envelope over the temperature peaks indicated an unmistakable reduction of cladding temperatures. The Lead Engineer'sjudgment regarding the limiting small break has been verified by subsequent analyses. With the benefit of hindsight, the Lead Engineer recognizes that more communication with NRC concerning the RELAP5YA MYAPS SBLOCA analyses would have been desirable, but believes that the analysis described in YAEC-1868 is a complete, accurate, and technically defensible SBLOCA analysis.

• Allegation III.B: The Lead Engineer carelessly disregarded NRC requirements because YAEC-1868, in its entirety, conceals the lack of an acceptable evaluation model to calculate ECCS performance for a ponion of the break spectrum between 0.35ft 2and at least 0.60ft.2 Response: Rather than concealing information, the YAEC LOCA Groep kept both Maine Yankee personnel and YAEC management fully informed of the technical issues and code limitations involved in the MYAPS SBLOCA analysis. Further, contrary to the statements in the Demand, YAEC-1868 accurately and completely describes the analysis, including the fact that the code " failed" to run at 0.35ft2 after the point of accumulator actuation. The Lead Engineer, therefore, could not have caused Maine Yankee to maintain and submit information that was not complete and accurate in all material respects.

. Allegation Ill.C: The RELAP5YA SBLOCA evaluation model descrioed in YAEC-1868, over-predicted core cooling from misapplication of the Alb-Chambre penetration correlation to derive the loss coefficient of 600 used for the split downcomer nodalization.

Response: This allegation appears to be based on the false premise that th ; Alb-Chambre correlation was used to derive a high cross-flow loss coefficient. The high K factor was used to improve the ECCS penetration into the downcomer and was based on 1 te understanding of the applicable data from experiments. The Alb-Chambre correlation was tna employed to confirm that the amount of ECCS penetration in the MYAPS SBLOCA anahsis was reasonable. Further, the QA error, which the Lead Engineer acknowledges, that appears to be at the heart of this alleged violation does not change the results of the SBLOCA analysis.

Ilad the calculation been executed correctly, the outcome would have been a negative value, an immediately recognizable non-physical result, which would have been traced to excessively conservative input values. If more reasonable values would have been input into the correlation, the result would have shown full ECCS penetration, confimiing the 3

e assumption used in the analysis. Contrary to over predicting core cooling, RELAP5YA, even with the use of a high loss coefficient actually under predicts core cooling, based on comparisons with applicable data from experiments and the results of subsequent analyses performed by Siemens.d Based on the record before the Commission,5 which, as determined by DE&S, does not support a conclusion of careless disregard, the Lead Engineer respectfully requests a letter from the Commission stating that she'did not disregard NRC regulations. Such a letter is just, as supported by the record before the Commission, and equitable, as demonstrated by the observations of Mr. Donald C. Prevatte in his root cause and corrective action assessment that is attached to the DE&S response:

Since the NRC's inspection that had initially identified these concerns, a great deal of these individuals' [the Manager and Lead Engineer) efforts have been directed toward defending against the allegations surrounding them. This appeared to have taken its toll on their ability to contribute to normal YAEC working endeavors and in their personal lives. Although the reviewer did not have the time to verify the accuracy of, or delve deeply into, the details of their individual stories, the perception derived from their interviews, other interviews, and other information gathered was that the personal damage these individuals had received and were continuing to receive was not commensurate with any technical orjudgement mistakes they may have made. (emphasis added) 1 4

The fact that RELAP5YA under predicts core cooling is further supported by the results of the Yankee Rowe SBLOCA analysis in which a similar approach was used to resolve the ECCS penetration problem. The Yankee Rowe plant has substantially more ECCS flow than Maine Yankee and other PWRs under SBLOCA conditions and, thus, should have no problem achieving penetration. Nonetheless, even with a high K, the code significantly under predicted ECCS penetration and produced higher than expected PCTs, thus demonstrating the conservative results produced by the code.

5 The Lead Engineer reserves the right to supplement this response as future circumstances may require.-

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The 1,ead Engineer requests that a letter finding that she did not disregard NRC requirements be placed in the Public Document Room as soon as practicable as a conclusion to the Lead Engineer's direct involvement in this matter.

Respectfully submitted, BAKER & BOTTS, L.L.P.

By:

Mitrk R. Robeck Texas Bar No. 16990040 1600 San Jacinto Center 98 San Jacinto Boulevard Austin, Texas 78701 Phone:(512) 322-2500 Fax:(512) 322-2501 Michael P. Lennon, Jr.

Texas Bar No. 00787895 3000 One Shell Plaza 910 Louisiana Houston, Texas 77002

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Phone:(713) 229-1234 Fax:(713) 229-1522 ATTORNEYS FOR THE LOCA GROUP LEAD ENGINEER 1

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