ML19329C219
| ML19329C219 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 04/30/1976 |
| From: | Tedesco R Office of Nuclear Reactor Regulation |
| To: | Deyoung R Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML19329C220 | List: |
| References | |
| NUDOCS 8002120940 | |
| Download: ML19329C219 (3) | |
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Docket No.:
50-346 R. C. DeYoung, Assistant Director for Light Water Reactors, FM RE7ISION TO THE DRAFE SAFETY EVALUATION REPORT - DAVIS BESSE hTCLEAR POWER STATION, UNIT 1 Plant Name: Davis-Besse Nuclear Power Station, Unit 1 Docket No.:
50-346 Licensing Stage: OL NSSS Supplier: Sabcock & Wilcox Containment Type: Dry Dual Architect Engineer: 3echtel Responsible 3 ranch and Project Manager: LWR Branch 4; L. Engle Review Status: Iacomplete Enclosed are revisions to the draf t Safety Evaluation Report for the Davis-Besse Nuclear Power 3tation, Unit 1, prepared by the Containment Systems Branch, and enclosed is a request for additional information.
Based on our review of the FSAR as amended (through Amendment 33), we concluded that the following openiiters of the draf t Safety Evaluation Report (issued February 12, 1975) have now been resolved:
1.
Bypass leakaZe paths have been identified in accordance wi.h the guidelines of 3 ranch Technical Position CSB 6-3.
The applicant has verbally agreed to eliminate the fuel transfer tube as a potential bypass leak path by demonstrating zero leakage through the fuel transfer tube. This comitment will be included in the Davis-1 case Unit 1 Technical Specifications.
2.
We have received mass and energy release data for the postulated design basis loss-of-coolant accident which does not include quenching of the ECCS vater. Using these revised release data, we calculated a peak containment pressure of 38.0 psig which confirms the acceptability of the applicant's contatment analysis and design pressure of 40.0 psig.
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We have received revised mass and energy release data for the subcompart-ment analysis that adequately describe the blowdown profile over the time scale of interest.
The results of our coni.rmatory analyses of the reactor cavity and steam generator compartments indicates that tha design pressures for these subcompart=ents are not acceptable based on the following results obtained by our analysas:
CS3 Results CS3 Kesults using conser-using L/A terms Desifsu Pressure vative L/A terms reduced by factor (psia)
(psia) of ten, psia Reactor Cavity 225 401 236 Stean Generators Compartment 114 204 113 The applicant should either re-evaluate the structural design capability of the subcompartments or provide revised analysas which show that proposed codifica-tions will reduce the peak pressure within the subcompartcents to below design values.
It should be noted that we considered inertial af fcces in our confirmatory analyses. This entailed usin;; inercia term (L/A, f t *) data from a similar plant (Three Mile Island 2) since we were not successful in getting this infor-r.ation from the applicant (Our efforts are d,escribed in the Memorandum to File fron D. Pickett, dated February 12, 1976, a copy of unich has been forwarded to the L?M). We felt the inertia terms from a siailar plant would conserva-tively describe the Davis-3 esse 1 subcompartments. Using these conservative values, we calculated pressures that are significantly greater than the subcoupartment design pressures; reducia;: the inertia terms by a factor of ten results in pressures whica confirm the design values. Since there is no sound basis for using these latter ine.rtia terms, we cannot justifiably accept the lower pressures. Therefore, wa are requesting the applicant to provida the inertia term data specifically for the Davis-3essell plant subcompartments, m -
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ItPR d " is/6 R. C. DeYoung i vessel support issue. This will be handled generically through the Division of Project Manage:nent.
Robert L. Tedesco, Assistant Director for Plant Systems Division of Systets Safety
Enclosure:
Raquest for Additional Information cc:
R. ;ieineman S. *danauer R. 3oyd
- J. Mcdonald W. Butler G. Lainas L.-Engla S. Varga J. Shapaker J. Kudrick D. Pickett J. Clynn c
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