ML20086K259

Application for Amend to License DPR-35,reflecting Use of Advanced GE-11 Fuel Design in Cycle 11

ML20086K259
Person / Time
Site:	Pilgrim
Issue date:	07/14/1995
From:	Boulette E BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20086K263	List: BECO-95-074, Application for Amend to License DPR-35,reflecting Use of Advanced GE-11 Fuel Design in Cycle 11 ML20086K266
References
BECO-95-074, BECO-95-74, NUDOCS 9507200074
Download: ML20086K259 (6)

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, $< 10CFR50.90 Boston Edison Pignm Nuclear Power Station Rocky Hill Road Plymouth, Massachusetts 02360 E. T. Boulette, PhD i senior Vice President - Nuclear .;uly 14, 1995 i BECo 95-074 l U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 ,

License DPR-35 Docket 50-293 Proposed Technical Specification Change to Section 2.1, Bases: Safety Limits; Section 3.3.C, Scram Insertion Times: and Section 4.11.C. Minimum Critical Power Ratio

- Boston Edison proposes the attached changes to Section 2.1, Bases: Safety Limits; Section 3.3.C, Scram insertion Times and Section 4.11.C, Minimum Critical Power Ratio (MCPR) of the Pilgrim Nuclear Power Station Technical Specifications in accordance with 10CFR50.90. The change to the Safety Limit Bases section is being proposed to reflect the use of the advanced GE-11 fuel design in cycle 11. The change to the scram insertion times is being proposed to simplify surveillance testing. The change in the method used to calculate the Minimum Critical Power Ratio is being proposed to reflect the new physics methods used to analyze the -

advanced fuel types. The Bases section will also be revised to reflect the 9x9 fuel rod arrays introduced in RFO 10. .

7 The requested changes are described in Attachment A, the proposed Technical Specification ,

pages are in Attachment B, and the current Technical Specification pages marked up to  !

indicate the requested revisions are in Attachment C. We request an expeditious review to support core power maneuvers during Cycle 11.

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E. T. Boulette, PhD  ;

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Commonwealth of Massachusetts) 4 County of Plymouth )

Then personally appeared before me, E. T. Boulette, who being duly swom, did state that he is Senior Vice President - Nuclear of Boston Edison Company and that he is duly authorized to i execute and file the submittal contained herein in the name and on behalf of Boston Edison '

Company and that the statements in said submittal are true to the best of his knowledge and ~

belief. /,' s My commission expires: M #f /99/ e  ! ,M' '

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' BOSTON EDISON COMPANY U. S. Nuclear Regulatory Commission  ;

I Page 2 cc: Mr. R. B. Eaton, Project Manager Division of Reactor Projects - 1/ll Office of Nuclear Reactor Regulation -

Mail Stop: 14D1 l U. S. Nuclear Regulatory Commission ,

1 White Flint North '

11555 Rockville Pike Rockville, MD 20852  ;

U. S. Nuclear Regulatory Commission Region 1 475 Allendale Road King of Prussia, PA 19406 Senior NRC Resident inspector  :

Pilgrim Nuclear Power Station

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ATTACHMENT A TO BECo LETTER 95- 074 PROPOSED CHANGE:

The proposed change to the Scram insertion Times reflects scram time test measurements which coincide with the actual Control Rod notch positions, thus making it easier for technicians to conduct scram time tests. Previous scram time testing was conducted using an adjustment factor to compensate for the difference between the relative rod position (i.e., %

insertion) specified in Technical Specifications and the actual reed switch " drop out" position, as well as the switch dimensions and the effect of magnetic hysteresis. The proposed change is conservative.

The proposed changes in the values of p and a used to calculate the Minimum Critical Power Ratio (MCPR) operating limits are consistent with the GEMINI advanced physics methods used to establish the PNPS operating limits. Use of these MCPR operating limits will ensure the MCPR safety limit is maintained in the event of an abnormal operating transient.

The proposed change to the bases of Section 2.1.1 deletes reference to the 7x7 and 8x8 rod arrays and updates the discussion to reflect the ac'vanced GE11 fuel design as the 9x9 rod arrays are the limiting fuel assemblies. Cycle 11 MCPR operating limits are based on the GE11 fuel design.

REASON FOR CHANGES:

Scram insertion Times The proposed change to the scram insertion time regtfrements is intended to simplify the surveillance procedure.

Currently, scram insertion times in Section 3.3.C of the Technical Specifications are stated in terms of the percentage of control rod insertion. The specific insertion percentages are 10%,

30%,50% and 90%. These percentages correspond to a non-integer number of control rod notches. Since scram insertion times are measured at integral notch numbers, compliance l with the Technical Specification limits had to be demonstrated by accounting for the difference  !

between the specified position and the actual notch position. The proposed notch position and scram times were chosen to correspond to the actual notch position of the scram time test measurement. They also include an allowance for the uncertainty in the location of the position indicating probes and an allowance for the uncertainty in the position of the control rods when " drop out" of the reed switch occurs. These changes make scram insertion time tests easier for technicians by eliminating the need to adjust the measured response.

The existing Technical Specifications also contain a requirement for inoperable control rods, j such tha'. if any rod has a scram time that exceeds 7.0 seconds at 90% insertion, it must be I declared inoperable The requirement is intended to identify those control rods with severely degraded scram performance. BECo proposes to apply the 7.0 second requirement to scram times measured at the " drop out" of notch position 04. This is consistent with this application at other GE BWRs and it is conservative.

MCPR Calculation Method The change in the values of p and a used for calculating the Option B Minimum Critical Power Ratio Operating Limits is proposed for consistency with the GEMINI advanced physics I analytical methods used to determine the Pilgrim Nuclear Power Station core operating limits Page 1

with advanced fuel types. Note: The current Core Operating Limit Report does not allow implementation of Option B. Option B is intended to be used for Fuel Cycle 11.

Fuel Claddina Intearity - Bases The proposed change to the Fuel Cladding integrity - Bases is considered administrative in nature. The information presented is consistent with that referenced in Revision 10 to GESTAR-il for the GE11 fuel design. Revision 10 to GESTAR-il has been approved by the NRC for generic use.

This fuel design determines the Cycle 11 MCPR operating limits.

DETERMINATION OF NO SIGNIFICANT HAZARDS The Code of Federal Regulations requires the Licensee to provide to the Commission its analysis concerning the issue of significant hazards. Therefore, the following analysis has been performed in accordance with 10CFR50.91 and 10CFR50.92:

Section 2.1 Bases - Safety Limits

1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated because equivalent fuel cladding protection (99.9 percent of all fuel rods do not experience transition boiling following a design basis transient) is provided.

2. The operation of Pilgrim Station in accordance with the proposed amendment will not r create the possibility of a new or different kind of accident from any accident previously evaluated because the proposed change does not affect the function of any structure, system or component.

3. The operation of Pilgrim Station in accordance with the proposed amendment will not involve a significant reduction in a margin of safety because the utilization of current General Electric fuel designs provides an equivalent margin of safety. As stated previously, equivalent fuel cladding protection is provided and ensures that 99.9 percent of all fuel rods will not experience transition t' oiling following a design basis transient.

Section 3.3.C - Scram insertion Times

1. The operation of Pilgrim Station in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated. The correlation of the scram insertion times with the actual notch position will simplify the surveillance procedure while maintaining the accuracy of the test.

2. The operation of Pilgrim Station in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated because no physical modifications are associated with the proposed change and it does not affect the function of any structure, system or component.

3. The operation of Pilgrim Station in accordance with the proposed amendment will not involve a significant reduction in a margin of safety. The notch positions were chosen to coincide with the relative insertion values specified in the Technical Specifications. Use of the proposed combination of notch positions and scram insertion times will maintain taage 2

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-the existing margins of safety that 99.9 percent of all fuel rods will not experience i

- transition boiling following a design basis transient.

Section 4.11.C - Minimum Critical Power Ratio (MCPR) Calculation Method

1. The proposed change does not involve a significant increase in the probability or consequences of an accident previously evaluated because the method used to I

calculate the measured scram speed distribution is consistent with the PNPS licensing basis.

2. The operation of Pilgrim Station in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from any accident previously evaluated because the proposed change does not affect the function of any structure, system or component.

3. The operation of Pilgrim Station ln accordance with the proposed amendment will not involve a significant reduction in the margin of safety because the proposed changes provide equivalent fuel cladding protection which ensures that 99.9 percent of all fuel rods will not experience transition boiling following a design basis transient.

These changes have been reviewed and recommended for approval by the Operations Review Committee and reviewed by the Nuclear Safety Review and Audit Committee.

Schedule of Chanae:

Expeditious review and approval of this change !c requested because of the potential fuel cycle impacts associated with core power maneuvers. The request is a result of the difference between P-1 calculated MFLCPR values and design MFLCPR values; with the P-1 calculated values being the more limiting of the two. These P-1 calculated MFLCPRs do not provide adequate margin for efficient and economic core power maneuvers. They also prevent operation with rod patterns required to realize the design cycle energy capability. Approval of .

this change will provide additional operating margin and facilitate efficient and economic core power maneuvers. ,

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Attachment B - Proposed Technical Specification l

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