ML19312C549
| ML19312C549 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/27/1974 |
| From: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| NUDOCS 7912160109 | |
| Download: ML19312C549 (15) | |
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1 UNITED STATES OF AMERICA ATOMIC ENERGY C0:D ISSION In the Matter of
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DUKE POWER C0'4PANY
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Docket Nos. 50-269
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50-270 (Oconee Nuclear Power Station,
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50-287 Units 1, 2, and 3)
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ORDER FOR MODIFICATION OF LICE'ISE I..
The Duke Power Conpany (the licensee) is the holder of facility licenses DPR-38, DPR-47 and DPR-55, which authorize operation of the Oconee Nuclear Power Station, Units 1, 2, and 3, respectively, in Oconee County, South Carolina.
These licenses provide, among other things, that they are subject to all rules, regulations and orders of the Co==1ssion now or hereafter in effect.
II.
Pursuant to the requirements of the Coc=ission's regulations in 10 CFR H 50.46, " Acceptance Criteria and Emergency Core Cooling Syste=s for Light Water Nuclear Power Reactors", on August 5, 1974, the licensee submitted an evaluatica of ECCS cooling performance calculated in accordance with an evaluation model developed by the Babcock and Wilcox Company ("the vendor"),
along with certain proposed technical specifications necessary te bring reactor operation into conformity with the results of the evaluation.
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9 2-The evaluation moder developed by the vendor has been analyzed by the regulatory staff for conformity with the requirements of 10 CFR Part 50, Appendix K, "ECCS Evaluation Models". The regulatory staff's evaluation of the vendor's model is described in two previously published documents:
Status Report by the Directorate of Licensing in the Matter of Babcock and Wilcox ECCS Evaluation Model Conformance to 10 CFR Part 50, Appendix K, issued October 15, 1974, and a Supplement to the Status Report, issued November 13, 1974.
Based on its evaluation, the regulatory staff has concluded that the vendor's evaluation model was not in complete conformity with the requirements of Appendix K and that certain modifications described in the
,a ove-mentioned documents were required in order to achieve such conformity.
b The regulatory staff assessments were reviewed by the Commission's Advisory Committee on Reactor Safeguards in meetings held on October 26, 1974, and November 14, 1974.
In its Report to the Chairman of the AEC, dated November 20, 1974, the Advisory Committee has concluded that "the four light-water reactor vendors have developed Evaluation Models which, with additional modifications required by the Regulatory Staff, will cog?crm to Appendix K to Part 50".
Since the licensee's evaluation of ECCS coolinS performance La based upon the vendor's evaluation model, the licensee's evaluation is similarly deficient.
The regulatory staff has assessed the effect of the changes required in the evaluation model upon the results of the evaluation of ECCS performance for e
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3 Oconee facilities submitted on August 5, 1974 and Septe=ber 20, 1974. This is described in the Safety Evaluation Report of the Oconee Nuclear Station Units 1, 2, and 3, Docket Nos. 50-269, 50-270 and 50-287, dated December 27, 1974.
On the basis of its review, the regulatory staff has determined that changes in operating conditions for the plant, in a,ddition to those proposed in the ' licensee's submittal of September 20, 1974 and August 5, 1974, are necessary to assure that the criteria set forth in E 50.46(b) are satisfied.
!Ihese additional changes, which are set forth in Appendix A to the Safety Evaluation Report, consist of modifications to the linear heat generation rate. These further restrictions will assure that ECCS cooling performance will conform to all of the criteria contained in 10 CFR S 50.46(b), which govern calculated peak clad te=perature, maximum cladding oxidation, maximum hydrogen generation, coolable geo=ctry and long term cooling.
These further restrictions were established on the basis of studies of the effect of model changes on the previously submitted evaluations. The regulatory staff believes that these restrictions should be verified by a re-analysis based upon an approved evaluation model, in conformity with 10 CFR H 50.46 and Appendix K.
During the interim, before an evaluation in conformity with the requirements of 10 CFR E 50.46 can be submitted and evaluated, the regu'tatory staff has concluded that continued conformance to therequirementsoftheCommission'sInterimAcceptanceCriteria7and conformance to the restr.ictions contained in the licensee's September 20, 1974 and August 5, 1974 submittals, together with the additional limitations set forth in Appendix A of the Staff Safety Evaluation Report, will provide
- Interim Acceptance Criteria for Emergency Core Ccoling Systems for Light i.'ater Pcwer Reactors, 36 F.R.12247, June 29,1971, as amended
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4-reasonabic assurance that the public heal.th and safety vill not be endangered.
These additional restrictions are set forth as Appendix A to this Order,
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i III.
In view of the foregoing and, in accordance with the provisions of E 50.46(a)(2)(v), the Acting Director of Licensing h.2s found that the evaluation of ECCS cooling perfor=ance sub=itted by the licensee is not consistent with the require =ents of 10 CFR E 50.46(s)(1) and that'the further restrictions set forth in this Order are required to protect the public health and safety.
The Acting Director of Licensing has also found that the public health, safety, and interest require that the following Order be =ade effective i==ediately. Pursuant to the
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ktomicEnergyActof1954,asa= ended,theCo==ission'sregu1ationsin10CFR
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EE 2.204, 50.46, and 50.54.
IT IS ORDERED THAT:
1.
As soon as practicable, but in no event later than six months fro = the date of publication of this order in the FEDERAL REGISTER, or prior to any license amendment authorizing any core reloading, whichever occurs first, the licensee shall submit a re-evaluation of ECCS cooling performance calculated in accordance with an acceptable evaluation model which confor=s with the provisions of 10 CFR Part 50, 2 50.4f,.
Such evaluation =ay be based upon the vendor's evaluation model as modified in accordance with the changes described in the Staff Safety Evaluation Report of the Oconee Nucicar Power Station, dated December.27, 1974. 'The evaluation vm
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shall be secompanied by such proposed changes in Technical Specifications or license amendments as may be necessary to implement the evaluation results.
2.
Effective im=ediately, reactor operation shall continue only within 4
the limits of:
(a) The requirements of the Interim Acceptance Criteria, the Technical Specifications, and license conditions imposed by the Cecmission in accordance with the requirements of the Interim Acceptance Criteria, and (b) The limits of the proposed Technical Specifications submitted by the licensee on September 20, 1974 and August 5, 1974, as =odified by the further restrictions set forth in Appendix A, attached hereto.
The license shall conform operation to the foregoing limitations until such time as the propose,d Technical Specifications required to be submitted in accordance with paragraph 1 above are. approved or modified and issued by the Commission.
Subsequent notice and opportunity for hearing will be provided in connection with such action.
IV.
Within thirty (30) days from the date of publication of.this Order in the FEDERAL REGISTER the licensee may file a request for a hearing with respect to this Order. Within the same thirty (30) day perigd any other person whose interest may be affected may file a request for a hearing with respect to this Order in accordance with the provisions of 10 CFR E 2.714 of the Commission's Rules of Practice.
If a request for a hearing is filed withih the time prescribed herein, the Commission will issue a notice of hearing or an appropriate order,
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t For further details with respect to this action, see (1) the licensee's submittals dated September 20,19,4 and August 5,1974 and vendor's topical 7
reports referenced in the licensee's submittals, which describe the vendor's evaluation codel, (2) the Status Report by the Directorate of Licensing in the Matter of Babcock and Wilcox ECCS Evaluation Model Conformance to 10 CFR 50, Appendix K, (3) Supplement 1 thereto dated November 13, 1974, (4) the Safety Evaluation Report dated December 27,1974, and (5) Report of the Advisory Committee on Reactor Safeguards. dated November 20, 1974.
All of these items are available at the Commission's Public Document Room,1717 H Street, NW., Washington, D.C., and at the Oconee County Library, 201 South Spring Street, Walhalla, South Carolina 29691.
A single copy each of items (2) through (5) may be obtained upon request addressed to the U.S. Atomic Energy Commission, Washington, D.C.
20545, Attention:
Deputy Director for Reactor Projects, Directorate of Licen' sing, Regualtion.
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DatedatBethesda,Marylandthisj(ldayofDecember,1974.
FOR THE AT0 HIC ENERGY COSIISSION h5
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Edson G. Case, Acting Director Directcrate of Licensing b
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s fl0TICE OF AVAILABILITY Copies of Appendix A to Order for Modification of License, dated December 27, 1974, are available for public inspection at the Commission's Public Document Room,1717 H Street, !!. W.,
Washington, D. C., or may be obtained upon request addressed to the Deputy Director for Reactor Projects. Directorate of Licensing, U. S. Atemic Energy Commission, Washington, D. C.
20545.
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APPENDIX A OPERATING RESTRICTIONS The Regulatory staff has reviewed the =ethods used by Babcock and Wilcox to derive the LOCA-related operating li=its for its plants.
The review considered the basic calculation method, the range of operating conditions calculated, the types of uncertainties and their
=agnitude, and the instec=entation provided to =0nitor plant operation.
Based on this review, we conclude that sufficient =onitoring instrumenta-tion is present to' provide assurance that the plant =ay be operated within LOCA-related operating restrictions. We further conclude that operation of Oconee Units 2 and 3 within the restrictions shown on Figures A-1 through A-3,which were a part of the, August 5,1974 proposed Technical Specifications frc= the licensee, will assure that the heat generation limits of Figure A-6 will not be exceeded.
For Unit 1, Figure A-4 already incorporates both criteria.
For Oconee Unit 1, we further
' conclude that the heat generatien li=its of Figure A-6 will not be exceeded if Unit 1 is operated within the Technical Specifications for cycle 2, provided that the following additional operating restrictions pursuant to the authority contained in 10 CFR 50.46 are imposed:
1.
The power level cutoff indicated in Figure 3 5-2-1A1 of the licensee's Septe=ber 20, 1974 sub=itted shall be reduced frc=
The power level cutoff is defined
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94 percent of rated power.
as the maxi =u= power at which the reactor can operate without regard to the reactivity held by xenon.
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2.
Power level shall not be greater than 92 percent (power level cutoff) unless one of the following requirements is cet:
a.
Quadrant tilt is less han or equal to 2.5 percent and the xenon reactivity is within 10 percent of the value for operation at steady-state rated power.
b.
Quadrant tilt is greater than 2.5 percent and the xenon reactivity is within 5 percent of the value for operation at steady-state rated power.
3 Operation shall be within the control rod withdrawal limits as shown in Figure A 4.
4.
Operation shall be within the power imbalance envelope as shown in Figure A-5.
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ROD It.Dit I S THE PERCENTAGE Stat of THE wa T. 0RAWAL. Of T*4t'. CPI RA I I r1G GPOvP S.
2 THC ADDI T ION AL RESTRICTIONS ON *iTHDRA't L (HASHED
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RESTRICTIONS ON WITHORAWAL IHASHED AREASI ARE T URTHFR MODI FI ED AFTER 435 FULL P0ivER DAYS Or OPERATION.
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