B15461, Application for Amend to License DPR-65 Re RT Setpoints
| ML20095J061 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 12/18/1995 |
| From: | Debarba E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES SERVICE CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20095J064 | List: |
| References | |
| B15461, NUDOCS 9512260289 | |
| Download: ML20095J061 (9) | |
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[]$ Utilities System Northeast 107 sem str-t, seriin, er 06037 j
North t criticie. service comp.oy P.O. Box 270 H.rtford, cr 06141-0270 (203) 665-5000 l-l December 18, 1995 l
Docket No. 50-336 B15461 Re:
i U.S. Nuclear Regulatory Commission i
Attention:
Document Control Desk Washington, DC 20555 Millstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision Reactor Trip Setpoints Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License, DPR-65, by incorporating the attached changes into the Technical Specifications of Millstone Unit No.
2.
The proposed changes affect Technical Specification Table 2.2-1.
Table 2.2-1 contains the Trip Setpoints and the Allowable Values for the Reactor Protective Instrumentation.
The Allowable Value for low Enactor Coolant System (RCS) flow is proposed to be changed based on the hardware changes completed during the last refueling outage that corrected deficiencies in the RCS flow loop instrumentation and the associated uncertainty calculations.
Additionally, an editorial change is proposed for the text associated with the allowable value.
. to this letter provides a safety assessment of the proposed changes.
is the dttermination of no j
significant hazards considerations.
Attachmeni. 3 is a copy of the i
marked-up version of the appropriate page of tne current Technical
~
Specifications.
Attachment 4
is the retyped Technical d
Specification page.
i NNECO has reviewed the proposed Technical Specification changes in accordance with 10CFR50.92 and concludes that the changes do not involve a significant hazards consideration.
NNECO has also reviewed the proposed. license amendment against the criteria of
.10CFR51.22 for environmental considerations and concludes that the changes do not significantly increase the types and amounts of i
effluent that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures.
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9512260289 951218 PDR ADOCK 05000336
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9 U.S. Nuclear Regulatory Commission B15461/Page 2 December 18, 1995 NNECO concludes that the proposal satisfies 10CFR51.22 (c) (9) for a categorical exclusion from the requirements for an environmental impact statement.
The Nuclear Safety Assessment Board has reviewed the proposed change to the Allowable Value in the Technical Specifications and concurs with the above determinations.
In accordance with 10CFR50.91(b), NNECO is providing the State of Connecticut with a copy of this proposed license amendment.
Since this proposed license amendment is not required to support continued safe operation, NNECO is requesting NRC review and approval at your earliest convenience with the amendment to be implemented within 60 days of issuance.
There are no commitments contained within this letter.
If the NRC Staff should have any questions or comments regarding this submittal, please contact Mr. Mario Robles at (860) 440-2073.
4 Very truly yours, l
NORTHEAST NUCLEAR ENERGY COMPANY E. A. DeBarba Vice President Attachments cc:
T. T. Martin, Region I Administrator G.
S. Vissing, NRC Project Manager, Millstone Unit No. 2 P.
D.
Swetland, Senior Resident Inspector, Millstone Unit Nos.
1, 2,
and 3 Mr. Kevin T.A. McCarthy, Director Bureau of Air Management Monitoring and Radiation Division Department of Environmental Protection 79 Elm Street Hartford, CT 06106-5127
4 U'.S. Nuclear Regulatory Commission B15461/Page 3 December 18, 1995 Subscribed and sworn t before me this
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day of 1995 e
Dat Commission Expires:
Kathleen T. Gabes Notary Public hiy Commission Expires December 31,1997 l
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j Docket No. 50-336 I
B15461 i
f Millstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision 4
Reactor Trip Setpoints Safety Assessment of Proposed Changes d
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December 1995 4
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U.S. Nuclear Regulatory Commission B15461/ Attachment 1/Page 1 December 18, 1995 Nillstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision Reactor Trip Setpoints Safety Assessment of Proposed Changes Dameription of Proposed changen The Allowable Value for the Reactor Coolant Flow Instrumentation contained in Table 2.2-1 is proposed to be changed to reflect the design changes implemented during the last refueling outage.
The Reactor Coolant System (RCS) Steam Generator Differential Pressure Instrumentation Loops have been modified to reflect a
re-calibration of the differential pressure transmitter from "-8 to 64 paid" to "O to 35 paid," and an elimination of the Foxboro signal characterizer modules from the instrument loop string.
The previous configuration resulted in excessive instrument errors.
i Licensee Event Report (LER) 95-012-00 documents the details regarding the larger than expected transmitter drift, the errors in 1
l the overall instrument loop uncertainty calculation, and misapplication of the calculated uncertainty in the Safety Analysis.
Additionally, an editorial change is proposed for the text associated with the allowable value.
The current wording " reactor 4
i coolant" is being changed to " reactor coolant flow."
4 Safety Assessment The change of the Allowable Value for the Reactor Coolant Flow Instrumentation in the Technical Specifications Table 2.2-1 is based on the hardware changes that corrected deficiencies in the RCS flow loop instrumentation and the associated uncertainty calculations.
These deficiencies resulted in errors which exceeded 1
the Safety Analysis assumptions.
The new Allowable Value has been calculated using an improved methodology.
The new hardware configuration results in calculated uncertainties which are bounded by the Safety Analysis assumptions.
The revised allowable value will continue to assure adequate forewarning of any setpoint degradation in the instrumentation prior to violating the trip i
setpoint credited in the Safety Analysis.
NNECO is administratively controlling the allowable value to the more conservative revised value to ensure safe operation while the proposed Technical Specification is reviewed by the NRC.
The proposed change is considered safe.
Additionally, the proposed change to add the word " flow" is an editorial correction, and thus does not affect safety.
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I Docket No. 50-336 B15461 9
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Millstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision i
Reactor Trip Setpoints Determination of No Significant Hazards Considerations i
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December 1995 1
U.S.
Nuclear Regulatory Commission B15461/ Attachment 2/Page 1 December 18, 1995 d
Millstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision Reactor Trip Setpoints Determination of No Significant Hazards Considerations Pursuant to 10CFR50.92, NNECO has reviewed the proposed changes.
NNECO concludes that these changes do not involve a significant hazards consideration (SHC) since the proposed changes satisfy the criteria in 10CFR50.92 (c).
That is, the proposed changes do not:
1.
Involve a
significant increase in the probability or consequences of an accident previously evaluated.
i The proposed change to the Allowable value of the Reactor Coolant Flow Instrumentation is based on design changes that reduce the uncertainties in the overall instrument loop, as well as improved calculation methodology for instrument uncertainty and setpoint.
The new hardware configuration results in calculated uncertainties which are bounded by the Safety Analysis assumptions.
There is no adverse impact on any design basis analysis due to this change, and, therefore does not affect the probability or consequence of any previously evaluated accident.
Additionally, the proposed change to add the word " flow" is an editorial correction and therefore does not affect the probability or consequence of any previously evaluated accident.
2.
Create the possibility of a new or different kind of accident from any accident previously evaluated.
The new Allowable Value has been calculated using an improved methodology.
The new hardware configuration results in calculated uncertainties which are bounded by the Safety Analysis assumptions.
The function of the Allowable value is i
not changed.
Therefore no new accident scenarios are created.
Additionally, the proposed change to add the word " flow" is an editorial correction and therefore no new accident scenarios are created.
3.
Involve a significant reduction in a margin of safety.
The change to the Allowable Value for the Reactor Coolant Flow Instrumentation reflects the design changes implemented during the last refueling outage.
The design improvement of the loop performance ensures that the assumptions of the Safety
i U.S. Nuclear Regulatory Commission B15461/ Attachment 2/Page 2 December 18, 1995 i
j Analysis are met.
Since the proposed changes do not affect j
the consequences of any accident previously analyzed, there is j
no reduction in a margin of safety.
i Additionally, the proposed change to add the word " flow" is an i
editorial correction and has no effect on the margin of safety.
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- Moreover, the Commission has provided. guidance concerning the i
application of standards in 10CFR50.92 by providing certain j
examples (51FR7751, March 6,
1986) of amendments that are j
considered not likely to involve an SHC. The proposed change to the Allowable Value resembles example (ix), a repair or replacement of a major component or system important to safety, meeting two 8
conditions:
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Condition (1) is met in that the repair or replacement process involves practices which have been successfully implemented at j
least once on similar components or systems elsewhere in the j
nuclear industry, or in other industries, and does not involve a significant increase in the probability or consequences of an accident previously evaluated or create the possibility of f
a new or different kind of accident from any accident j
previously evaluated.
Condition (2) is met in that the repaired or replacement component or system does not result in a significant change in its safety function or a significant reduction in any safety limit (or limiting condition of operation) associated with the l
component or system.
i Additionally, the proposed change to add the word " flow" is an j
editorial correction and resembles example (1),
a purely j
administrative change to technical specifications, which for 1
example include a change to achieve consistency throughout the l
technical specifications, correction of an error, or a change in
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nomenclature.
This editorial change has no effect on the protective boundaries or the margin of safety.
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Docket No. 50-336 B15461 s
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Millstone Nuclear Power Station, Unit No. 2 Proposed Technical Specifications Revision Reactor Trip Setpoints Marked-up Version of Current Technical Specifications i
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December 1995
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