ML15016A274

Draft RAIs License Amendment Request for Change to TS 3.4.10 P/T Limits (TAC Nos. MF4597 and MF45980)

ML15016A274
Person / Time
Site:	Susquehanna
Issue date:	01/16/2015
From:	Whited J A Plant Licensing Branch 1
To:
Jeffrey Whited, NRR/DORL
References
TAC MF4597, TAC MF4598
Download: ML15016A274 (2)

Text

DRAFT DRAFT REQUEST FOR ADDITIONAL INFORMATION OFFICE OF NUCLEAR REACTOR REGULATION LICENSE AMENDMENT REQUEST FOR CHANGE TO TECHNICAL SPECIFICATION 3.4.10 PPL SUSQUEHANNA, LLC SUSQUEHANNA STEAM ELECTRIC STATION UNITS 1 AND 2 DOCKET NOS. 50-387 AND 50-388 By letter dated August 11, 2014, 1 PPL Susquehanna, LLC (PPL, the licensee) submitted a license amendment request to revise Technical Specification 3.4.10, "RCS Pressure and Temperature (P/T) Limits," for the Susquehanna Steam Electric Station (SSES), Units 1 and 2.

Specifically, the licensee proposed to revise the P/T Limits curves to extend them into the vacuum region to address vacuum fill operations. To complete its review, the Nuclear

Regulatory Commission (NRC) staff requests a response to the questions below.

RAI 1 BACKGROUND

Title 10 of the Code of Federal Regulations Part 50, Appendix G, "Fracture Toughness Requirements," requires that P/T limits be developed to bound all ferritic materials in the reactor vessel (RV). Further, Sections I and IV.A of 10 CFR Part 50, Appendix G specify that all ferritic reactor coolant pressure boundary (RCPB) components outside of the RV must meet the applicable requirements of American Society of Mechanical Engineers Boiler and Pressure Vessel Code (ASME Code),Section III, "Rules for Construction of Nuclear Facility Components."

ISSUE As clarified in Regulatory Information Summary (RIS) 2014-11, 2 "Information on Licensing Applications for Fracture Toughness Requirements for Ferritic Reactor Coolant Pressure Boundary Components," P/T limit calculations for ferritic RV components other than those materials with the highest reference temperature, may define curves that are more limiting than those calculated for the RV beltline shell materials because the consideration of stress levels from structural discontinuities (such as nozzles) may produce a lower allowable pressure.

REQUEST Describe how the P/T limit curves for SSES Units 1 and 2 consider all ferritic pressure boundary components of the reactor vessel that are predicted to experience a neutron fluence exposure greater than 1x1017 n/cm2 (E > 1 MeV) at the end of the licensed operating period.

1 Agencywide Documents Access and Management System (ADAMS) Accession Number ML14223A780.

2 ADAMS Accession No. ML14149A165.

DRAFT If the current P/T limit curves do not consider all ferritic pressure boundary components of the reactor vessel that are predicted to experience a neutron fluence exposure greater than 1x10 17 n/cm 2 (E > 1 MeV) at the end of the licensed operating period, provide appropriately revised P/T limit curves to the NRC staff for review.

RAI 2 BACKGROUND 10 CFR 50.36(b) states, in part, that: "The technical specifications will be derived from the analyses and evaluation included in the safety analysis report, and amendments thereto, submitted pursuant to § 50.34."

ISSUE Page 3 of 7 of the licensee's application states, in part, that:

The absolute maximum vacuum is assumed to be no greater than 15 psig Whereas the licensee's proposed Technical Specifications (TS) change on TS Figures 3.4.10-1 thru 3 shows P/T limit curves are extended to -100 psig. Any TS change should be consistent with technical justification.

REQUEST Please provide a justification for an extension of the P/T curves to -100 psig, or, TS Figures 3.4.10-1 through 3.4.10-3 should be revised to reflect the maximum vacuum of -15 psig as described in the submittal (i.e., adjusting the axis to end at -15 psig, terminating the P/T curves at -15 psig on the current scale, etc.).