ML19344E618
| ML19344E618 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 08/27/1980 |
| From: | Parker W DUKE POWER CO. |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8009020371 | |
| Download: ML19344E618 (3) | |
Text
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DUKE POWER COMPANY POWER BUtuMNO 422 Soctn Caracu Starzt, CuAntoTTz N. C. asa4a w w 4n o.**ana.a.
August 27, 1980 Vict Petsiotut TELeewow. Amta 704 Sf tau Paoovenog 373-4083 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.' 20555 Re: McGuire Nuclear Station Docket Nos. 50-369, 50-370
Dear Mr. Denton:
During a conversation with Duke personnel on August 26, 1980 it was agreed that it would be beneficial to share Duke Power's position on hydrogen controi in ice condenser containments with the Staff at this time. Your staff was advised of our activities by conference calls in early June and August of this year. The purpose of this letter is to document those activ-ities and provide a current status of our work in this area. As a preface to the following remarks regarding specific actions that Duke has taken, I would reiterate that McGuire will have an Emergency Core Cooling System (ECCS) which has been designed to meet the low concentration limits required by 10CFR 50.46.
The NRC Staff confirmed this point in its Safety Evaluation Report, Supplement No. 2, March 1979, p. 6-4.
Accordingly, operation of the ECCS, as designed, will not result in the generation of substantial quanti-ties of hydrogen (in excess of the design basis of 10CFR 50.44).
Further assurance of proper operation of the ECCS is provided by meeting the require-ments for the Near-Term Operating License Plants set forth in NUREG-0694.
These requirements have resulted in (1) changes in McGuire administrative procedures, (2) hardware modifications of the plant, (3) increased and more comprehensive training programs, and (4) additional and better informed con-trol room personnel. Duke believes that the McGuire ECCS will prevent any hydrogen problem from developing and conclude that McGuire can be operated at 100% power without posing any undue risk to the public health and safety.
As previously stated to your staff, the hydrogen control issue has prompted a vigorous work activity at Duke that has been directed by a task force formed to focus on this issue. This task force has performed work specifi-cally related to McGuire, reviewed TVA and NRC developments and monitored ongoing institutional and industry activities. The current work activities of the task force are divided into short-term and long-term efforts:
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Mr. Harold R. Denton, Director August 27, 1980 Page Two Short-Term 1.
A consultant has been retained to prepare a risk evaluation for the M:Ouire facility. This consultant is assessing the relative significance of hydrogen at McGuire. This evaluation is expected to be complete by the end of September.
2.
A consultant has been retained to study the pressure and temperature response of the McGuire ice condenser containment using the CLASSIX computer code.
This code is discussed in an NRC Staff report to the Commission dated August 13, 1980. This work is expected to be complete in October.
3.
A detailed analysis of the structural integrity of the McGuire contain-ment is being performed using finite element analysis (MARC computer code).
The design pressure for the McGuire containment is 15 psig. Preliminary results of our structural analysis show a yield Jactor of approximately 3.1 (46.5 psig) and a failure safety factor of approximately 4.6 (69 psig).
4.
Currently an experimental program in cooperation with Tennessee Valley Authority on the ignition of hydrogen, air, steam mixtures is ongoing through Westinghouse and Fenwall, Incorporated. This work is expected to be complete by the end of September.
5.
Detailed design work of a hydrogen mitigation system has begun using, distributed controlled ignition sources. This system will be simila r to the program proposed by TVA and presently under review by the NRC.
a final decision on installation of the distributed ignition system will be made when information resulting from the above short-term activities and the NRC testing at Lawrence Livermore Laboratory is available.
Long-Term 1.
A joint effort with TVA has been instituted to study hydrogen generation and mitigation. We have retained a consultant to study halon suppression and are examining proposals from other consultants to study hydrogen generation phenomena.
2.
Duke and TVA have met with EPRI to review proposed EPRI research into hydrogen combustion and containment integrity.
Therefore, as evidenced by the above short and long-term activity, Duke is actively participating in an extensive examination of the hydrogen matter. This examination does not result from a license requirement and, accordingly, McGuire can be licensed for full power operation. Duke concurs with the NRC Staff conclusion that:
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Mr. Harold R. Denton, Director August 27, 1980 Page Three
. on balance that, pending the rulemaking proceeding, continued operation and licensing of nuclear plants with ice condenser containments is justified.
" Proposed Interim Hydrogen Control Requirements For Small Containments" at p. 29 (February 22, 1980); see also SECY-80-107B at p. 4 (June 20,1980)).
Additionally, the ACRS in a July 15, 1980 letter addressing the Sequoyah facility concluded that the incomplete status of review and analysis of oydrogen mitigation systems need not delay the issuance of c full pcwer license.
In summary, we reiterate our belief that the McGuire Emergency Core Cooling System will prevent any hydrogen problem from developing and McGuire can be operated at 100% power with no undue risk to the public health and safety.
Certainly, the evidence dictates that, at a minimum, McGuire can safely operate at 100% power pending the outcome of the degraded core rulemaking proceeding.
ry truly yours,.
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William O. Parker, Jr.
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Mr. D. F. Ross U. S. Nuclear Regulatory Comme.ssion i
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