ML20046B909
| ML20046B909 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 07/30/1993 |
| From: | Opeka J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20046B910 | List: |
| References | |
| B14563, NUDOCS 9308090010 | |
| Download: ML20046B909 (5) | |
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NORTHEAST UTILITIES General OMices e Seiden Street, Berlin, Connecticut 1
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P O. DOX 270 HARTFORD. CONNECTICUT 06141-0270 J C 2 CN,7,,,
(203) 665-5000 L
L July 30, 1993 f
D.ocket No. 50-423 814563 l
Re:
10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Gentlemen:
Millstone Nuclear Power Station, Unit No. 3 Proposed Revision to Technical Specifications Borated Water Sources Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend Operating License NPF-49 by incorporating the attached proposed changes into the Technical Specifications of Millstone Unit No._3.
Description of the Proposed Chance The purpose of this proposed change is to increase the volume requirements of the boric acid storage system of Technical Specification 3.1.2.6 in order to meet the requirements of the redesigned core for Cycle 5 operation.
Backaround This proposed change is the result of a redesigned core for Cycle 5.
The Millstone Unit No. 3 Cycle 5 core has been redesigned as a result of assembly re-caging. The redesign results in shuffling 80 of the 193 fuel assemblies in the original Cycle 5 loading pattern.
This redesign is required due to grid-to-rod fretting, resulting from a flow-induced vibration problem identified at the Salem and Beaver Valley Plants. The results'of the redesign are:
All once-burnt VANTAGE 5H fuel assemblies that were originally located on the baffle have been moved inboard.
t Eight twice-burnt STANDARD fuel assemblies that were originally located inboard have been moved to baffle locations.
Forty-eight of the fresh Region 7 VANTAGE 5H fuel assemblies were i
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re-caged.
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As.a direct result of the new loading pattern changes, many of 'the core physics characteristics (which include power distributions, control rod i
worths, an gl boron concentration) have changed and now produce larger I
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B14563/Page 2 i
July 30, 1993 l
boron concentration swings from Modes 1 and 2 to Modes 4 and 5.
The changes to these boron swings were not large, but were sufficient to use up the small amount of margin available in the original calculation. The proposed limit is consistent with the increased requirements as defined in the " Millstone Unit 3 l
Cycle 5 Redesign Reload Safety Evaluation.""'
NNE0 was informed by Westinghouse on July 16, 1993, that the boric acid system volume requirements would need to be revised.
The revised Reloading Safety Evaluation (RSE) was received on July 23, 1993.
Discussion The specifications for Modes 1 through 4 nquire that enough boric acid be i
contained in the boric acid system to borate the plant to hot shutdown (Mode 4) and cold shutdown (Mode 5).
The starting point for this boration is considered to be ftam either r~de 1 or 2 The redesign of the core resulted in an increase in the amoeat of boric acid required to make these mode changes.
The proposed change increases the required volume in the boric acid storage system in Modes 1 through 4 from 21,020 gallons to 21,802 gallons.
This change affects Specification 3.1.2.6 (Page 3/4 1-18) and its corresponding basis on Page B 3/4 1-3.
This change is necessary to support Cycle 5 operation prior to initial entry into Modes 1 or 2.
The wording changes - to the basis reflect the fact that more advanced core loading patterns have altered the traditional limiting cases for this type'of analysis.
It is no longer true that full power, end-of-life conditions are necessarily the most limiting.
~ a revised wording reflects the more varied range of possible limiting condit as.
The proposed changes are provided in Attachment 1 (Marked Up) and Attachment 2 (Retyped).
Safety Assessment The Westinghouse safety evaluation (Attachment 3) provides analysis and evaluation of the Cycle 5 core design resulting from the following:
1.
Reshuffling of fuel assemblies to relocate VANTAGE SH assemblies that '
were originally located on the baffle.
2.
New VANT.'.3E SH fuel assemblies were re-caged due to findings at Salere and Beaver Valley.
(1)
" Millstone Unit 3 Cycle 5 Redesign Reload Safety Evaluation," dated July 1993.
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a U.S. Nuclear Regulatory Commission B14563/Page 3 July 30, 1993 3.
Assemblies were introduced with ZIRLO components.
Only the reshuffling of the assemblies has resulted in the need to increase the minimum limit of borated water storage.
The introduction of ZIRLO components is not a direct factor in this proposed modification to the technical specifications.
The borated water storage tanks are designed to accommodate the proposed minimum limit.
There are no hardware changes associatad with the increased storage volume and no change to the functioning of any equipment.
Therefore, there are no malfunctions that could possibly be caused by this change.
No new performance requirements are being imposed on any system or component such that any design criteria will be exceeded as documented in the RSE, nor will they cause the core to operate in excess of design ba.is operating limits.
Sionificant Hazards Consideration In accordance with 10CFR50.92, NNEC0 has reviewed the attached proposed changes and has concluded that they do not involve a sigaificant hazards consideration (SHC). The basis for this conclusion is that the three criteria of 10CFR50.92(c) are not compromised.
The proposed changes do not involve an SHC because the changes would not:
1.
Involve a significant increase in the probability or consequences of an accident previously evaluated.
The Cycle 5 reload core design meets all applicable design criteria and ensures that all n:rtinent licensing basis acceptance criteria are met.
The demonstrated adherence to the:;e standards and criteria precludes new challenges to components and systems that could:
(a). adversely affect the ability of existing ccmponents and systems to mitigate the consequences of any accident and/or; (b) adversely affect the integrity of the fuel rod cladding as a fission product barrier.
Furthermore, adherence to applicable standards and criteria ensures that these fission product barriers maintain the design margin of safety.
This f s a change to the technical specifications only.
There are no hardware changes (i.e., the tanks are designed to accommodate the new limit) associated with the prcposed change.and no change to the functioning of any equipment which could affect any accident precursors.
Therefore, the probability or consequences of any previously evaluated accident is not significantly increased.
c U.S. Nuclear Regulatory Commission B14563/Page 4 July 30,1993 j
2.
The proposed changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.
This change reflects the revised RSE.
There are no hardware changes associated with it and no change to the functioning of any equipment which could introduce new or unique accident precursors.
All design and performance criteria will continue to be met and no new cingle-failure mechanisms have been created as documented in the RSE, nor will they cause the core to operate in excess of pertinent design basis operating limits.
Therefore, the possibility of an accident of a diffennt type l
than any previously evaluated in the FSAR has not been created.
p 3.
The proposed changes do not involve a significant reduction in a margin of safety.
The RSE documents that the margin of safety, as defined in the Bases to the Millstone Unit 3 Technical Specifications, is not reduced.
The Cycle 5 reload core redesign meets all applicable design criteria and ensures that all pertinent licensing basis acceptance criteria are met.
It has been determined that the Millstone Unit No. 3 VANTAGE SH reload design and safety analysis limits remain applicable, and that these limits are supported by the applicable Millstone Unit No. 3 Technical Specifications for Cycle 5.
This change is more restrictive in that it increases the volume requirements for the boric acid storage system in Modes I through 4.
This change is necessary to support Cycle 5 operation prior to initial entry into Modes I or 2.
However, the current analysis of record remains bounding with this proposed change in place.
Therefore, the change will not affect any of the plant's safety analysis and will have no impact in i
the margin of safety.
Moreover, the Commission has provided guidance concerning the application of standards in 10CFR50.92 by providing certain examples (51FR7751, March 6, 1986) of amendments that are considered not likely to involve an SHC.
The changes proposed herein are not enveloped by a specific example. As described above, the proposed changes do not constitute an SHC since there is no active mechanism being modified that would affect the physical or operating characteristics of plant systems or equipment. The minimum required volume of boric acid storage is being increased in the technical specifications; however, the actual storage capacity of the tanks is more than adequate.
In accordance with 10CFR50.91(b), we are hereby providing the State of-Connecticut with a copy of this proposed amendment, NNEC0 has reviewed the proposed license amendment against the criteria of 10CFR51.22 for environmental considerations.
The proposed changes do not increase the type and amounts of effluents that may be released off site, nor significantly increase in!!vidual or cumulative occupational-radiation
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- .o U.S. Nuclear Regulatory Commission B14563/Page 5 July 30,1993 exposures.
Based on the foregoing, NNECO concluded that the proposed changes meet the criteria delineated in 10CFR51.22(c)(9) for categorical exclusion for the requirements for an environmental impact statement.
The Millstone Unit No. 3 Nuclear Review Board has reviewed and approved the l
proposed changes and has concurred with the above determination.
Regarding our proposed schedule for this amendment, we request issuance at your earliest convenience, but no later than September 22, 1993, with the amendment effective as of the date of issuance, to be implemented within 30 days of issuance.
Should Millstone Unit No. 3 enter Modes 1 or 2 during the-scheduled refueling outage before the technical specification change is issued, NNEC0 will implement administrative controls to comply with the more restrictive shutdown margin requirements addressed in this proposal.
We recognize the short-time constraints to process this amendment request and offer to meet with the Staff if it would help to expedite the review.
Should the Staff require any additional information to process this request, NNECO remains ave.ilable to promptly provide such information.
Very truly yours, NORTHEAST NUCLEAR ENERGY COMPANY J. F. Op_eka O
Executive Vice President cc:
T. T. Martin, Region I Administrator V. L. Rooney, NRC Project Manager, Millstone Unit No. 3 P. D. Swetland, Senior Resident Inspector, Millstone Unit Nos.1, 2, and 3 Mr. Kevin McCarthy, Director Radiation Control Unit Department of Environmental Protection Hartford, CT 06116 i
Subscribed and sworn to before me this_3dM day of 94/b,1993 J
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