ML19317E725
| ML19317E725 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 12/27/1974 |
| From: | Case E US ATOMIC ENERGY COMMISSION (AEC) |
| To: | |
| Shared Package | |
| ML19317E714 | List: |
| References | |
| NUDOCS 7912180869 | |
| Download: ML19317E725 (14) | |
Text
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9 UNITED STATES OF AMERICA ATOMIC ENERGY COMMISSION In the Matter of
)
)
DUKE POWER COMPANY
)
Docket Nos. 50-269
)
50-270 (Oconee Nuclear Power Station,
)
50-287 Units 1, 2, and 3)
)
ORDER FOR MODIFICATION OF LICENSE I.
The Duke Power Company (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 cubject to all rules, regulations and orders of the Commission now or hereafter in effect.
II.
Pursuant to the requirements of the Commis~sion's regulations in 10 CFR R 50.46, " Acceptance Criteria and Emergency Core Cooling Systems for Light I
Water Nuclear Power Reactors", on August 5, 1974, the licensee submitted an l
evaluation 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 to bring reactor operation into conformity with the results of the evaluation.
79121sa8[7
2-The evaluation model 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 Modelu'. The regulatory staff's evaluation of I
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 above-mentioned documents were required in order to achieve such conformity.
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 conform to Appendix K to Part 50".
I Since the licensee's evaluation of E CS cooling performance is 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
a
Oconce fccilities submitted on August 5, 1974 and September 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 addition 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 B 50.46(b) are satisfied.
These 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 E 50.46(b), which govern calculated peak clad temperature, maximum cladding oxidation, maximum hydrogen generation, coolable geobetry and long term cooling.
These further restrictions were established on the basis of studies of the ffect 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 I
conformity with the requirements of 10 CFR E 50.46 can be submitted and l
evaluated, the regulatory staff has concluded that continued conformance to the requirements of the Commission's Interim Acceptance Criteria and conformance to the restrictions 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 Cooling Systems for Light Water Power Reactors, 36 F.R.12247, June 29,1971, as amended 1& P D SAA01 n..-L,.
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reasonableassurancethatthepublicheal[thandsafetywillnotbeendangered.
These additional restrictions are set forth as Appendix A to this Order.
I III.
6 In view of the foregoing and, in accordance with the provisions of 8 50.46(a)(2)(v), the Acting Director of Licensing has found that the evaluation of ECCS cooling perfosmance submitted by the licensee is not consistent with the requirements of 10 CFR E 50.46(a)(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, safr.ty, and interest require that the following Order be made effective immediately. Pursuant to the ktomicEnergyActof1954,asa= ended,theCommission'sregulationsin10CFR El 2.204, 50.46, and 50.54.
IT IS ORDERED THAT:
1.
As soon as practicable, but in no event later than six months from the date of publication of this order in the FEDERAL REGISTER, or prior to any license amendment authorizing any core reloading, whichever I
occurs first, the 1 censee shall submit a re-evaluation of ECCS cooling performance calculated in accordance with an acceptable evaluation model 1
which conforms with the provisions of 10 CFR Part 50, 5 50.46.
Such evaluation may 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 Nuclear Power Station, dated December.27, 1974. 'The evaluation
shall be accompanied by such proposed changes in Technical Specifications or license amendments as may be necessary to implement the evaluation results.
2.
Effective immediately, reactor operation shall continue only within the limits of:
(a) The requirements of the Interim Acceptance Criteria, F.4e Technical Specifications, and license conditions imposed by the Commission in accordance wir.h 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 modified 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 proposed 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 FEDERALREGISTERthelicenseemayfilearequestforahearfngwithrespect to this Order. Within the same thirty (30) day, period 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 f 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, f
For further details with respect to this action, see (1) the licensee's submittals dated September 20, 1974 and August 5, 1974 and vendor's topical reports referenced in the licensee's submittals, which describe the vendor's evaluation model, (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 Safeguard: 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.
DatedatBethesda,Marylandthis$J}dayofDecember,1974.
FOR THE ATOMIC ENERGY COMMISSION
/s/
Edson G. Case, Acting Director Directorate of Licensing 4
4 1-
APPENDIX A l
OPERATING RESTRICTIONS
~ ~..
The Regulatory staff has reviewed the methods used by Babcock and Wilcox to derive the LOCA-related operating limits for its plants.
The review considered the basic calculation cethod, the range of operating conditions calculated, the types of uncertainties and their magnitude, and the instrumentation provided to conitor plant operation.
Based on this review, we conclude that sufficient monitoring instrumenta-tion is present tc~ provide assurance that the plant may 've 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 from 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 generation limits 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 September po,1974 sub=itted shall be reduced froc 94 percent of rated power. The power level cutoff is defined as the maximum power at which the reactor can operate without regard to the reactivity held by xenon.
e A-1 4
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2.
Power level shall not be greater than 92 percent (power level cutoff) unless one of the following requirements is met:
a.
Quadrant tilt is less than or eqtd 1 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 operatier. 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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R0fs i t.DE t IS THE PERCFNTAGF SIN OF Ts40 wf1HDRAWAL OF Test. CPI RA II tJG GROUP S.
2 THE AI)DI T I ON AL RESTRICTIONS ON AiTHORAWAL (HASHED arf AS ) ARE kOD8 FI ED ArlfR 100 rULL POWER DAYS 05 OPFR A T I ON.
125 187 217 100
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Restricted
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Power Level Cutet!
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5 OPERATING REGION 20 i
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50 t00 150 200 250 300 Rod Index
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Group 5 FIGURE A-1 CONTROLR00GROUPhlTH0RAWALLil41TS
.FOR 4 PUMP OPERATION - UNITS 2, 3 e
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POD lNDEX 15 THE PERFENTAGF* SUM Of THF AsTHD4A#AL OF THE UPI RAT t hG GROiJPS.
2.
THE AlDITIONAL RESTRICTIONS ON WITHDRA5AL (HASHED AREASI ARE IN EFrECT AF TER 100 FL.L L POY.ER D AY S O f ODERATION.
RESTRICTIONS ON WITHI)RAWAL lHASHED ARLASI arf. ItJRTHf R MODI FI ED AFTEP 435 FULL POWER DAYS Or OPERATION.
100 125 182 253 //
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90 90 182 253 80 Restrictett Power Level Region g
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PERM,lSSIBLE OPERATING s
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- 1. ROD INDEX l S THE PERCEr.TAGE StrA OF THE WI THORAWAL OF THE OPERAl' NG GROUP S.
- 2. THE ADDI TION AL RESTRICTIONS ON WI THDRAWAL (HASHED AREAS) ARE IN EFFECT AFTER 435 FULL POWER DAYS OF
' OPERATION.
291.4 100
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82.5 POWER ]
244-5 80
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RESTRICTED a.
REGION LEVEL Nithdrawal Limit
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%8 PERMISSIBl.E 60 o
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REGION E2 40 g
20 e
f f
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f 50 100 150 200 250 300 Rod index. ', Wi thdrawal 0
25 50 75 100 t
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Group 7 0
25 50 75 100 I
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t t
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Group 5 FIGURE A-3 CONTROL R00 GROUP WITHDRAWAL L.lMITS FOR 4 PUMP OPERATION UNITS 2, 3 A :
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Red 1:00s is the "Centage sus of the cithdre:el of the sp*
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The withdf asal limits are modified ef ter 250 2 5 full coser days of eparation.
4 373 203.'7 100 I
Poser Level 93 160 Cutoff Restricted 204.2 Region g
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Permissible c
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N Region y
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50 100 150 200 250 300 Pod indet, 5 Withdrawal 25 50 15 100 E
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Ep5 FICURE,A-4
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CONTROL ROD GRO'JP WITHDRAWAL LIMITS FOR 4 PUMP OPERATION
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UNIT 1 O
me e
A-6
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Po:er, 5 of 2568 Mtt
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60 52,-27.0 50
+28.1, 52 l
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10 20 30 Core imbalance, 5 u-FIGURE lA-5 OPERATIONAL POWER DBALANCE ENVELOPE O e.ee UNIT 1 A-7f
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18 16 CD UNITS 2, 3
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12
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8 to 12 Distance from inlet, ft FIGURE A-6 LOCA LIMITED MAXIMUM ALLOWABLE LINEAR HEAT RATE i
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8 4
A-8 G
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