B13830, Application for Amend to License DPR-65,changes Time Prior to Reduction of Shutdown Margin for Special Test Exceptions Shutdown Margin Surveillance Requirements

Application for Amend to License DPR-65,changes Time Prior to Reduction of Shutdown Margin for Special Test Exceptions Shutdown Margin Surveillance Requirements

ML20079B405
Person / Time
Site:	Millstone
Issue date:	06/10/1991
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20079B406	List: B13830, Application for Amend to License DPR-65,changes Time Prior to Reduction of Shutdown Margin for Special Test Exceptions Shutdown Margin Surveillance Requirements ML20079B415
References
B13830, NUDOCS 9106170042
Download: ML20079B405 (3)

Text

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. NORTHEAST UTILETIES c n,.. oi,4.. . s,.n a,..,. n.,i,n c-,.n,m E I.Id..Y,C .'IEU.C P O DOx 270 C.",7lJL'i[1, HMtTf OnD. CONNE CTICUT 06141-0270 L L A w.w v s ww., I?Oh bCb4000 June 10, 1991 l Docket No. 50 336 E11019 Re: 10CFR50.90 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 i l

Gentlemen:

Millstone Nuclear Power Station, Unit No. 2 Pro)osed Change to Technical Specifications ,

S lutdown Marain Special Test Exception i Pursuant to 10CFR50.90, Northeast Nuclear Energy Company (NNECO) hereby proposes to amend its Operating License No. DPR 65 by incorporating the changes identified in Attachment 1 into the Technical Specifications of Millstone Unit No. 2.

Dheussion ,

The existing Technical Specification 4.10.1.2, "Snecial Test Exceptions, Shutdown Margin Surveillance Requirements," states that each control element assembly (CEA) not fully inserted shall be demonstrated capable of full ,

insertion when tripped from at least the 50% withdrawn position within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prior to reducing the shutdown margin to less than the limits of Specification 3.1.1.1.

9 Subsequent to a refueling outage, low power physics testing is performed to verify physics parameters. The tests which determine CEA group worths may result in a reduction of the shutdown margin below that normally required for operation in Modes 2 and 3. Prior to reducing the shutdown margin below the technical specification limits, any CEA not fully inserted is required to have been demonstrated capable of full insertion within the past 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The group worth tests typically commence more than 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the CEA drop '

time surveillance. As such, compliance with the present surveillance requirements results in an additional scram. This scram causes increased ,

component wear, complicates and delays completion of low power physict tests, ,

and results in decreased plant availability. As such, the proposed change will extend the time prior to the reduction of shutdown margin, such that CEA -

insertion capability will be demonstrated within the previous 7 days rather than within the previous 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

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U.S. Nuclear Regulatory Commission B13030/Page 2 June 10, 1991 Signific4ntHazardLCantidtrAllan The proposed technical specification change has been reviewed against the criteria o'/10CfR50.92 and it has been determined not to involve a significant hazards co'isideration. Specifically, the proposed change does not:

1) Involve a significant increase in the probability or consequences of an accideat previously analyzed. Technical Specifications require the surveillance for the CEA drop time to be performed following reactor reassembly During reactor operation, it is typically many months between uses of the reactor trip system that include the full insertion of the CEAs. The change in the surveillance from 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> to 7 days will still result in a test being performed far more frequently than would occur during normal operation. Therefore, there is not a significant change in the probability of failure for any safety system.

2. Create the possibility of a new or different kind of accident from any previously anal,ned. This proposed Technical Specification change does not modify pl a .t response such that i t could be considered a new accident. There are no new credible failure modes associated with this change. The results and effects of the change are consistent with those accidents already analyzed.

3. Involve a reduction in the margin of safety. Neither the drop time nor the CEA worth is affected by the change. Therefore, there is no impact on the performance of any safety system. There is no increase in the consequences of any accident ind, as such, there is no reduction in the margin of safety.

The Com.ission has provided guidance concerning the application of standards in 10CFR50.92 by providing certain examples (51FR7751, March 6, 1986). The proposed changes described herein, in some respects, resemble example (vi).

This example involves a change which cither may result in some increase to the probability or consequences of a previously analyzed accident or may reduce in some way a safety margin, but where the results of the change are clearly within all acceptable criteria with respect to the system or component as specified in the Standard Review Plan (e.g., a change resulting from the application of a small refinement to a previously used calculational model or design method). As with this example, NNEC0's proposed amendment involves no significant hazards consideration.

The Millstone Unit No. 2 Nuclear Review Board has reviewed and approved the attached proposed revision and has concurred with the above determinations.

rirdw respectf ully requests that this proposed change be issued prior to the start of the next refueling outage currently planned for March 1992. NNECO also requests this license amendment be effective as of the date of its issuance, to be implemented within 30 days of issuanca.

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. j U.S. Nuclear Regulatory Commission B13830/Page 3 June 10, 1991 in accordance with 10CFR50.91(b), we are providing the State of Connecticut with a copy of this proposed amendment application.

Very truly yours, I l

NORTHEAST NUCLEAR ENERGY COMPAt4Y  !

f;) -

/ W Senio Vice President l cc: Mr. Kevin McCarthy i Director, Radiation Control Unit Department of Environmental Protection (

Hartford, Connecticut 05116 T. T. Martin, Region i Administrator '

G. S. Vissing, NRC Project Manager, Hillstone Unit No. 2 ,

P. Habighorst, Resident inspector, Hillstone Unit No. 2 W. J. Raymond, Senior Resident inspector, Hillstone Unit Nos. 1, 2, and 3 STATE OF CONNECTICVT ss. Berlin l COUNTY OF HARTFORD 1 hen personally appeared before me, E. J. Hroczka, who being duly sworn, did

state that he is Senior Vice President of Northeast Nuclear Energy Company, a Licensee herein, that he is authorized to execute and file the foregoing i information in the name and on behalf of the Licensee herein, and that the statements contained in said information are true and correct to the best of his knowledge and belief.

c .L u ea " 'd MNY NotaryPuS

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