BECO-91-076, Application for Amend to License DPR-35,revising Thermal & Pressurization Limit Curves of Tech Specs Figures 3.6.1 & 3.6.2 & Adding New Curve to Figure 3.6.3 to Cover Operation Between 10 & 32 Effective Full Power Years

Application for Amend to License DPR-35,revising Thermal & Pressurization Limit Curves of Tech Specs Figures 3.6.1 & 3.6.2 & Adding New Curve to Figure 3.6.3 to Cover Operation Between 10 & 32 Effective Full Power Years

ML20079C362
Person / Time
Site:	Pilgrim
Issue date:	06/11/1991
From:	Gina Davis BOSTON EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20079C363	List: BECO-91-076, Application for Amend to License DPR-35,revising Thermal & Pressurization Limit Curves of Tech Specs Figures 3.6.1 & 3.6.2 & Adding New Curve to Figure 3.6.3 to Cover Operation Between 10 & 32 Effective Full Power Years ML20079C364
References
BECO-91-076, BECO-91-76, NUDOCS 9106190274
Download: ML20079C362 (5)

Text

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e 10CFR 50.90 e ,  :

BOSTON EDISON Pilgrim Nuclear Power Staton Rocky Hdi Road PNmouth, Massachusetts 02360 George W. Davis BECo 91-076 Senor Vice Presdent - Nxies' June 11, 1991 U.S. Nuclear Regulatory Commission Document Control Desk Hashington, DC 20555 License DPR-35 Docket 50-293 ProDosed Chanaes to the Reactor Pressure Vessel Thermal and Pressurization Technical Sp_ecification Limits Boston Edison Company (BECo) proposes the attached changes to the Pilgrim Nuclear Power Station (PNPS) Technical Specifications. These proposed changes revise the thermal and pressurization limit curves of figure 3.6.1 and 3.6.2, and adds a new curve figure 3.6.3, to cover operation between 10 and 32 effective full power years (EFPY). Also included are changes to associated limiting condition for operation (LCO), surveil.ance, and bases sections.

These changes comply with Generic Letter 88-11 and Regulatory Guide 1.99, Revision 2.

The requested changes are described in Attachment A, the revised Technical Specification pages are in Attachment B, and Attachment C provides existing pages marked-up to show the proposed changes. ,

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Attachments I signed original and 37 copies cc: see next page Commonwealth of Massachusetcs)

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Then personally appeared before me, Roy A. Anderson, who being duly sworn, did state that he is Vice President - Nuclear Operations and Station Director of Boston Edison Company and that he i. duly authorized to 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.

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', BOSTON EDISON COMPANY U. S. Nuclear Regulatory Commission Page 2 cc: Mr. R. Eaton, Project Manager Division of Reactor Projects - I/II '

Office of Nuclear Reactor Regulation Mail Stop: 14D1 U. S. Nuclear Regulatory Commission 1 White Flint North 11555 Rockville Pike Rockville, MD 20852 U. S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Senior NRC Resident Inspector l

Pilgrim Nuclear Power Station Mr. Robert M. Hallisey, Director Radiation Control Program Massachusetts Department of Public Health 305 South Street Jamaica Plain, PA 02130 l

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Attachment to BECo 91-076 ATIACHHENT A ProDosed Chances to the Reactor Pressure Vessel Thermal and Pressurization Limits Erpposed Chanae:

Boston Edison Company (BECo) proposes revising the Pilgrim Nuclear Power Station (PNPS) Technical Specifications and associated Bases to comply with Generic Letter 88-11: "NRC Position on Radiation Embrittlement of Reactor Vessel Materials and its Impact on Plant Operations", dated July 12, 1988, and with Regulatory Guide 1.99, Revision 2, " Radiation Embrittlement of Reactor Vessel Materials", dated May 1988. Figures 3.6.1 and 3.6.2 are replaced with revised Figures 3.6.1, 3.6.2, and a new figure, Figure 3.6.3. Changes to l associated limiting condition for operation (LCO) s?ctions, surveillance sections, and bases are also proposed to reflect the referenced NRC guidance.

To clarify existing Figure 3.6.2, we propose dividing the information presented in Figure 3.6.2 into two separate Figures, 3.6.2 and 3.6.3. The two figures will distinguish subcritical heatup/cooldown from critical core operation. The limits for subcritical heat';p/cooldown are shown on revised Figure 3.6.2, and the limits for critical core operation are shown on new Figure 3.6.3. The reactor pressure vessel (RPV) thermal and pressurization limits have been adjusted to reflect a more accurate prediction of the effects of accumulated ,

neutron exposure to the RPV over the life of the plant. '

Reason for Chanae:

The purpose of Specification 3.6.A, " Thermal and Pressurization Limitations,"

is to establish operating limits that provide a wide margin to preclude brittle failure of the reactor pressure vessel. The basis of the Pressure-Temperature (P-T) limits is_found in Appendix G to 10CFR50.

These changes to the Technical Specifications are proposed to conform to the provisions of 10CRF50, Appendix G, Fracture Toughness Requirements, and Appendix H, Reactor Vessel Surveillance Program Requirements.

This proposal incorporates predicted shifts in reference nil ductility temperature (RTuo7) which were derived from the guidelines contained in Regulatory Guide 1.99, Rev. 2, and are based on material chemical and physical data for the Pilgrim vessel obtained from the vessel fabricator, steel manufacturer, and other sources under-the QA programs in existence at the time of manufacture.

These revised pressure temperature limits are also based on the most conservative option of Regulatory Guide 1.99, Revision 2, regarding beltline weld chemical composition, that is, upper bound weld chemistry of 1.0 percent nickel and 0.35 percent copper because actual data for the described weld metal composition are not available for h11 of the welds on the Pilgrim vessel.

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The proposed changes are being made because Regulatory Guide 1.99, Revision 2 revised the methodology used to evaluate neutron radiation embrittlement of reactor vessel beltline materials. Generic Letter 88-11 requested licensees to use Revision 2 of the regulatory guide to evaluate pr d cted embrittlement.

BECo has reevaluated the effect of neutron radiation on reactor vessel materials using these two NRC documents and is changing the RPV thermal and pressurization limits contained in the PNPS technical specifications to reflect the reevaluation. This proposed change is consistent with the requirements of Section V of 10CFR50, Appendix G.

The RPV thermal and pressurization limit curves of Figures 3.6.1, 3.6.2, and 3.6.3 have been expanded to account for the effects of accumulated neutron exposure projected for the duration of the initial Pilgrim license. The figures incorporate the results of a detailed neutron transport analysis which addresses the beneficial effects of the low leakage core loading scheme adopted af ter Pilgrim's Cycle 5.

In addition, thermal and pressurization limit curves for the reactor vessel bottom head have been incorporated into Figures 3.6.1 and 3.6.2 to account for the less stringent stress and fracture toughness code requirements. These bottom head curves also take into consideration thermal-hydraulic effects due to flow stratification within the reactor vessel.

Administrative changes are included to clarify the Technical Specification in Section 3/4.6 and to conform, in part, to NUREG-0123, Revision 3 Standard Technical Specification for General Electric Boiling Hater Reactors, dated Fall 1980. In particular, we propose revising Technical Specification Section 4.6.A.1 to clarify that the surveillance to verify LC0 3.6.A.1 is only required when vessel temperature is below 450'F.

Other changes revise the text of Section 3/4.6.A and its associated bases to reflect the new limits on pressure and temperature and to provide consistency.

Page 125 is included in the change to allow for repagination and to correct a typographical error in section 4.6.B.2. Specifically, " chlorine" is corrected to " chloride" to be consistent with the LC0 listed in section 3.6.B.2.

These proposed changes are administrative in nature, do not involve any physical modification to the plant, and do not introduce any new failure modes. The changes do not alter the conclusions of the safety analyses contained in Pilgrim's FSAR and the NRC Staff's Safety Evaluation Report.

Determination of No Sianificant Hazards Consideration:

The Code of Federal Reaulations (10CFR50.91) requires licensees requesting an amendment to provide an analysis, using the standards in 10CFR50.92, that determines whether a significant hazards consideration exists. The following analysis is provided in accordance with 10CFR50.91 and 10CFR50.92 for the proposed amendment:

1. Operation of the Pilgrim Nuclear Power Station in accordance with the proposed amendment will not involve a significant increase in the probability or consequences of an accident previously evaluated. The effect of neutron radiation on reactor vessel materials has been recalculated using the latest NRC-approved guidance (Regulatory Guive 1.99, Revision 2). The resultant changes to the pressure-temperature limits contained in Specification 3.6.A will preclude brittle fracture failure of the reactor vessel.

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Changes are also proposed to Section 3/4.6.A and its associated bases to reflect the new pressure-temperature curves. Th2se changes are editorial in nature and, as such, do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Operation of Pilgrim Nuclear Power Station in accordance with the proposed amendment will not create the possibility of a new or different kind of accident from those previously evaluated. The proposed changes are administrative because they revise existing limitations in accordancc: with NRC guidance; they do not involve any physical modification to the plant, and they do not introduce any new failure nodes.

The changes to Section 3/4.6.A and its bases section are editorial in nature and do not create the possibility of a new or different kind of accident from those previously evaluated.

3. Operation of Pilgrim Nuclear Power Station in accordance with the proposed amendment will not involve a significant reduction in the margin of safety. The margin of safety is increased because the new pressure-temperature limitations are more conservative (restrictive) and result from the use of a more accurate method for predicting radiation embrittlement.

The changes to Section 3/4.6.A and its bases section are editorial in nature and do not involve a significant reduction in the margin of safety.

This change was reviewed by the Operations Review Committee, and they recommended its approval by the Station Director. It was also reviewed by the Nuclear Safety Review and Audit Committee.

Schedule of Chanae This change will be implemented within 30 days following BECo's receipt of its approval hy the NRC.

NRC approval of this amendment is needed before Pilgrim reaches 10 effective full power years (EFPY) which is projected to occur in mid-1992.

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