ML17331A707

Forwards Second Quarterly Rept on Hydrogen Mitigation & Control & Technical Rept Re Limiting Internal Uniform Pressure Capacity

ML17331A707
Person / Time
Site:	Cook
Issue date:	04/24/1981
From:	Hunter R INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG
To:	Harold Denton Office of Nuclear Reactor Regulation
Shared Package
ML17326A884	List: ML17326A883 ML17331A707 ML17331A708
References
AEP:NRC:00500A, AEP:NRC:500A, NUDOCS 8104290515
Download: ML17331A707 (3)

Text

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[NDIANA L MICHIGAN ELECTRIC COMPANY P. Oa BOX 18 BOWLING GREBM STATIOH NEW YORK, H. Y. 1000i April 24, 1981 AEP:NRC:00500A Donald C. Cook Nuclear Plant Unit Nos. 1 and 2 Docket Nos. 50-315 and 50-316 .

License Nos. DPR-58 and quarterly Report on Hydrogen Mitigation and Control DPR-74'econd Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory ComIission Washington, D. C. 20555 g

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Dear Mr. Denton:

This letter and its attachments constitute our second quarterly report on hydrogen..mitigation and control for the Donald C. Cook Nuclear Plant Unit [los. 1 and 2. This report is b'eing submitted in fulfillment of the commitment made in our AEP:NRC:00476 submittal dated October 7, 1980 and supplements the information previously transmitted to the Commission

.via our first quarterly report, AEP:NRC:00500, dated January 12, 1981.

As stated in our first quarterly report, installation of the in-containment portion of a Distributed Ignition System (DIS) is scheduled

-during the 1981 refueling outages for Unit Nos. 1 and 2 of the Cook Plant.

Detailed information concerning the in-containment portion of the DIS is provided in Attachment No. 2 to this letter as requested by members of your Staff. Design of the outside-containment portion of the DIS has been completed and the necessary material orders placed. Our efforts are directed toward having the DIS operational in Unit No. 2 by June 1, 1981.

The attachments to this letter address the various topics associated with a hypothetical event resulting in the generation of sub-stantive amounts of hydrogen. This information is provided in the attachments as follows:

Mr. Harold R. Denton AEP:NRC:00500A Attachment No. - ~To ic Containm'ent Structural Evaluation 2 Distributed Ignition System Design 1

3 Inadequate Core Cooling/f{ydrogen Control Equipment Equipment Survivability Research Program Status Core Cooling Capability Subsequent=to @drogen Combustion Preliminary Safety Evaluation As 'stated in Section 2.0 of the enclosure to our AEP:NRC:00500 submittal, AEP is investigating various candidate hydrogen control methods in conjunction with Duke Power Company and the Tennessee Valley Authority.

An evaluation o'f the studies performed to date with regard to Halon inerting,=

Electro-magnetic interference emissions from spark discharge igniters, and the use of catalytic combustors will be forwarded to the NRC in our next sub-mittal on this topic.

Testing .performed by AEP/TVA/Duke/Westinghouse at Fenwal Incorporated verified the ability of the glow plug igniter utilized in the DIS to reliably ignite lean hydrogen/air/steam mixtures in the presence of water spray and fans. Confirmatory tests. performed by the Lawrence Livermore Laboratory (UCRb-84167) further substantiated our conclusions. with regard to the Fenwal test results; that is, the glow plug igniter is a reliable ignition source under a variety of adverse conditions. The contaihment pressure and temperature responses to hydrogen combustion have been conservatively estimated using the CLASIX computer code. The=results of the CLASIX analyses show that de-liberate ignition of hydrogen would not pose a threat to containment integrity and would not result in environmental conditions more severe than the con-ditions to which most of the necessary equipment has been qualified to.

Based on the results of. the aforementioned testing and analyses, we have concluded that the DIS would serve to reduce the consequences of hypo-thetical events similar in nature to the TMI-2 accident involving the gener-ation of substantive amounts of hydrogen. The research and development programs, described in Attachment No. 5 to this letter (being funded by AEP/

TVA/Duke in conjunction with the E1ectric Power Research Institute}, are ex-pected to provide confirmatory information in support of the DIS mitigation concept. The merits of any potential modification .to the present DIS design uncovered during the research program will be duly considered.

Mr. Harold R. Denton 3 AEP:NRC:00500A

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A t smal'l break loss-of;coolant accident. with failed hypotth e lca 1 sma ECCS injection '{S2D) has been analyzed and the acceptabslity of the D IS mits ation concept shown for the hydrogen generation associated with-a roximately 80 weight percent zircohium cladding oxidation; a more f hydrogen control standpoint than the TMI-2 accident.

In light of the knowledge gained from the above mentioned, test ing and analyses, as supplemented by our continued awareness of the issues 'dis-cussed by the NRC Staff with regards to the Sequoyah and McGuire Nuclear lants, 1

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is our position that the DIS described in Attachment No. 2 to o stitute the final hydrogen control system for the Donald C. Cook Nuclear Plant pending completion of the gene ric de g raded

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core rulema k sng. It vs ouur belief that consideration of additional event sequences, beyond S2D is not warranted at this time.

Indiana 8 Michigan Electric Company .interprets 10 CFR 170.22 as requiring that no fee accompany this submittal.

Very truly yours, h

Y R. S. Hunter Vice President cc: Dohn E. Dolan - Columbus R. C. Callen

,G. Charno'ff D..V. Shaller -'ridgman R. M. Jurgensen Region III Site- Inspector