ML19322B391
| ML19322B391 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 11/24/1975 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML19322B377 | List: |
| References | |
| NUDOCS 7912020239 | |
| Download: ML19322B391 (3) | |
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UNITED f.T ATES NUCLEAR REGULATORY COMMISSb..
W ASHINoToN, D.
C.
20555 4
SAFE'lY EVALUATION BY Tile OFFICE OF NUCLEAR REACTOR REGULATION SUPPORTING M1ENDMENT NO.15 TO FACILITY LICENSE NO. DPR-38 CllANGE NOS5 TO TECllNICAL SPECIFICATIONS; AMENDMENT NO.15 TO FACILITY LICENSE NO. DPR-47 CIIANGif.h0. 2 0 TO TECIINICAL SPECIFICATIONS; MfENDMENTk'O. I 2 TO i:ACILI'IY LICENSE NO. DPR-55 CHANGE'NO. 1 p TO TECifNICAL SPECIFICATIONS DUKE POWER COMPANY OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3 IBCKET NOS. 50-269, 50-270, NJD 50-287
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Introduction By letter dated November 10, 1975, Duke Power Company (the licensee) requested a change in the Technical Specifications of Licenses No. DPR-38, DPR-47, and DPR-55 for the Oconee Nuclear Station, Units 1, 2, and 3.
The proposed amendments would provide Oconee Unit I control rod position (withdrawal) and operational power imbalance limits for four pump operation applicable to the period after 245 + 10 Effective Full Power Days (EFPD) of operation.
Discussion On December 27, 1974, the staff issued an Order for Modification of License (the Order) which required that the licensee submit a reevaluation of Oconee Emergency Core Cooling Systems (ECCS) performance and identified the limits for continued reactor operation during the interim.
These limits were a combination of existing technical specifications, technical specification changes previously submitted by the licensee, and additional restrictions of Appendix A to the Order.
The additional restrictions were considered necessary.in order to compensate for deficiencies noted in the Babcock 6 Wilcox (BGW) ECCS evaluation model and 'rere imposed to assure continued conformance to the criteria of 10 CFR 50.46 until the ECCS reevaluation required by the Order received final approval by the staff.
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. Figure A-4 of Appendix A to the Order established the control rod withdrawal limits and Figure A-5, the ' associated power imbalance limits for Oconce Unit 1.
Note 2 on Figure A-4 states that "the withdrawal limits are modified after 250 + 5 full power days of operation". The appropriate limits for operation beyond 250 EFPD were not included in the Order since it was anticipated that staff approval for the limits based on the FAC (Final Acceptance Criteria) for ECCS cooling performance would be issued prior to 250 EFPD of operation of Oconce Unit 1.
- However, staff evaluation of the licensee's revised FAC submittal is not yet complete and may not be completed before withdrawal of control rod group 7 (presently precluded by Figure A-4) is necessary to maintain full power operation. The licensge has indicated that, based on current boron concentration measurements, Group 7 may be required at 235 EFPD instead of the previously estimated 250 EFPD. Accordingly, the licensee, by application dated November 10, 1975, has requested
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approval of rod withdrawal limits, and associated power imbalance limits, for operation beyond 245 + 10 EFPD.
Evalua' ion t
The changes required in the B6W ECCS cvaluation model necessitated a series of sensitivity studies by B6W to identify the effect of the model changes on the results of previous calculations affecting the Oconce units.
Our review of the results of these studies revealed that the operating restriction for Oconce Unit 1 as identified in Appendix A to the Order would be required to ensure that in the event of a postu-lated loss-of-coolant accident (LOCA), the ECCS cooling performance would not exceed the values for calculated peak clad temperature and oxidation and nydrogen generation limits, set forth in 10 CFR 50.46.
These operating restrictions included, among other things, the rod withdrawal and axial power imbalance limits of Figures A-4 and A-5, previously mentioned.
The proposed rod withdrawal and axial power imbalance limits for opera-tion beyond 245 1
1 0 EFPD were calculated by the licensee using methods we have previously found acceptable-and upon which we relied in establishing the necessary operating restrictions in the Order.
We, therefore, conclude that operation of Unit 1 beyond 245 + 10 EFPD with the pro-posed rod withdrawal and axial power imbalance limits, and with no change in the other operating restrictions in the Order, will assure that ECCS cooling performance will continue to conform to all of the criteria contained in 10 CFR 550.46(b), which govern calculated peak clad temperature, maximum cladding oxidation, maximum hydrogen generation, coolable geometry and long-term cooling.
The incorporation of these new limits in tha technical specifications does not conflict with nor require revisio" of the Order since with respect to the rod withdrawal limits, the requirement for new limits c
een Val
. (for operation beyond 250 EFPD) was recognized and provided for in the Order and, with respect to the axial power imbalance limits, the new limits are more restrictive than those in the Order.
In summary, we have concluded that the preposed rod withdrawal and power imbalance limits for Oconec Unit 1 meet the requirements of the Order of December 27, 1974, and provide reasonable assurance that the public health and safety would not be endangered.
We, therefore, find the proposed amendment to be acceptabic.
Conclusion We have concluded, based on the considerations discussed above, that:
(1) because the change does not involve a significant increase in the probability or consequences of accidents previously considered and does not involve a significant decrease in a safety margin, the change does not involve a significant hazards consideration, (2) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (3) such activities will be conducted in compliance with the Commission's regulations and the issuance of these amendments will not be inimical to the common defense and security or to the health and safety of the public.
Date:
NOV 2 41975 9
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1911111D STA17.S NUCLEAR REGULATORY CONGSSION DOCKET N05. 50-269, 50-270 3DID 50-287 DUKE POWER COMPANY NOTICE OF ISSUANCE OF AMENDMENTS '!D FACILI1Y OPERATING LICENSES Notice is hereby given that the U.S. Nuclear Regulatory Comissica 13, (the Commission) has issued Amendments No.15,15.Iand 1@toPacility.jee.,[ {'s.,
Operating Licenses No. DPR-38, DPR-47, and DPR-55, respectively, issued to Duke Power Company which revised Technical Specifications-for operation of the Oconee Nuclear Station, Units 1, 2, and 3, located in Oconee County, South Carolina, no amendments are effective as of the date of issuance.
nese amendments provide Oconee Unit I control rod position and operational power imbalanco limits for four-pump operation applicable to the period after 245 + 10 Effective Full Power Days of operation.
ne application for the amendments complies with the standards and' requirements of the Atomic Energy Act of 1954, as amended (the Act),
e and the Comission's rules and regulations. no Comissian has made
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appropriate findings as required by the Act and the Commission's rules '
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and regulations in 10 CPR Chapter I, which are set forth in the license--
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amendments. Prior public notice of these amendments is not required sines
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the amendments do not involve a significant hazards consideration.,
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Form AEC-Ste (Rev.9-53) AECM 0240 are..ss-le-eness-t ses ers h..
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?00R ORIGINAL For further details with respect to this action, see (1) the applia
-c cation for amendments dated November 10,197$,(2) Amendmentt No.15
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andig to bicenses No. DPR-38, DPR-47, and DPR-55, with Changes No.2 5,
i 2 0,tand ig and (s) the Commission's related Safety evaluation.
All of these items are available for public inspection at the Commission's Public Doctament Room,1717 H Street, NN., Washington, D.C. and at the Oconee
\\ County Library, 201 South Spring Street, Walhalla, South Carolina 29691.
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., C - A copy of items (2) and (3) may,be obtained upon request. addressed -
to the U.S. Nuclear Regulatory Connission, Washington, D.C.
- 20555, Attention Director, Division of Reactor Licensing.
Dated at Bethesda, Maryland, this NOV 2 dlS75 FOR 'n!B NUCLEAR REGUIATORY COINISSION Thbmas P.. Wambsch,! Acting Chief Operating Reactors Branch #1 Division of Reactor Licensing A, -j.
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