ML14162A432

PSEG Slides for Seismic Reevaluation Public Meeting

ML14162A432
Person / Time
Site:	Salem
Issue date:	06/11/2014
From:	PSEG Power
To:	Office of Nuclear Reactor Regulation
Difrancesco N, NRR/JLD, 415-1115
References
Download: ML14162A432 (15)

Text

NTTF 2.1 - Seismic Reevaluation - Salem GMRS June 12, 2014

2.1 Ground Motion Response Spectra (GMRS)

Purpose:

To present the basis for Salem GMRS submittal in March 2014 and discuss resolution and path-forward with FLEX Implementation and Expedited Seismic Evaluation Process (ESEP)

Basis for soil velocity profiles Basis for estimation of effective kappa Impact on FLEX Implementation Impact on ESEP Resolution Screening 2

2.1 Ground Motion Response Spectra (GMRS)

Current GMRS Values - EPRI v NRC 3

2.1 Ground Motion Response Spectra (GMRS)

Basis for Salem GMRS submitted March 2014 September 2013 submittal to the NRC provided three base case velocity profiles informed by Early Site Permit (ESP) and Salem stratigraphy Provided by EPRI in accordance with NRC endorsed SPID, EPRI 1025287 Soil Velocity Profile randomization in accordance with SPID Appendix B kappa in accordance with SPID Appendix B 4

2.1 Ground Motion Response Spectra (GMRS)

Basis for Soil Velocity Profiles ESP had a total of 16 borings

• 8 borings 3/4 mile north of Salem

• 8 borings 1/2 mile east of Salem Shear wave velocity (Vs) measurements made in four borings

• 2 borings 3/4 mile north of Salem (1 boring reached Potomac formation)

• 2 borings 1/2 mile east of Salem (1 boring reached Potomac formation)

Geologic stratification at the ESP site and Salem site is similar, however Salem layer thicknesses are slightly different 5

2.1 Ground Motion Response Spectra (GMRS)

Salem and ESP Site Boring Locations 6

2.1 Ground Motion Response Spectra (GMRS)

Basis for Soil Velocity Profiles Salem site specific layer thicknesses were used For shallow layers (<~450 ft depth), ESP shear wave velocity measurements for each layer were used, measurements taken approximately 1/2 - 3/4 mile away For deep layers (>~450 ft depth), no local Vs measurements were available; regional compressional wave measurements were used to infer Vs Since the velocity measurements are not located at the Salem site, 3 velocity profiles used to characterize uncertainties in Vs as recommended in SPID Section B-3.2 7

2.1 Ground Motion Response Spectra (GMRS)

Basis for epistemic uncertainties in Vs ln(mean Vs) = 0.20 for shallow (<~450 ft) layers based on ESP Vs values ( 1/2 - 3/4 mile away) - Tertiary and Cretaceous sands, silts, and clays - SPID Section B-3.2 ln(mean Vs) = 0.35 for deeper (>~450 ft) layers based on estimated Vs values from regional compression wave measurements used to infer Vs - Cretaceous Potomac formation - SPID Section B-3.2 8

2.1 Ground Motion Response Spectra (GMRS)

Basis for estimation of effective kappa NRC GI-199 Hazard Estimates (ML100270691) characterized Salem as a soil site in 2010 ESP site characterized as a soil site for the GMRS development EPRI Report 1023389, Evaluation of Seismic Hazards at Central and Eastern U.S. Nuclear Power Sites, 2011 characterized Salem as a deep soil site September 2013 submittal to the NRC provided soil profile that includes 1761 feet of soil as supported by Salem UFSAR Figure 2.5-5 EPRI GMRS total kappa value of 0.037s calculated using SPID Appendix B, Section B-5.1.3.1 for soil sites less than 3000 feet thick:

soil effective (ms) = 0.0605*H (thickness in meters)=0.031s At design loading levels, uncertainty in kappa accommodated by 2 models of shear modulus and hysteretic damping curves 9

2.1 Ground Motion Response Spectra (GMRS)

Seismic - Impact on FLEX (example) and ESEP Motor Control Centers (MCCs) installed in the plant to support primary FLEX electrical strategy Considered part of the ESEL, must meet ESEP criteria for RLGM ESEP Criteria - Section 4: Review Level Ground Motion Spectrum (RLGM) - The RLGM will be derived by linearly scaling the SSE by the maximum ratio of the GMRS/SSE between the 1 and 10 hz range (not to exceed 2 x SSE)

ESEP Criteria - Section 5: required to demonstrate that ESEL items have sufficient seismic capacity to meet or exceed the demand characterized by the RLGM.

GMRS level impacts FLEX and ESEP in the calculation of the required RLGM 10

2.1 Ground Motion Response Spectra (GMRS)

Seismic - GMRS Resolution and Screening

• GMRS Resolution - Use EPRI GMRS EPRI GMRS was performed in accordance with the SPID PSEG is proceeding with FLEX design using EPRI GMRS to meet NRC Order EA-12-049 for October 2014 FLEX implementation at Salem Unit 1 Proceeding with ESEP based on the EPRI GMRS to meet 10CFR50.54(f) requirement for ESEP report submittal by December 31, 2014 11

2.1 Ground Motion Response Spectra (GMRS)

Questions?

12

2.1 Ground Motion Response Spectra (GMRS)

Current GMRS Values - EPRI v NRC 13

2.1 Ground Motion Response Spectra (GMRS)

Seismic - GMRS Resolution and Screening

• Screening Salem UFSAR Section 3.7 requires all Seismic Category I Systems, Structures and Components (SSCs) to be evaluated to the SSE time history based on the El Centro earthquake (UFSAR Figure 3.7-2)

ESEP review of design calculations confirms Salem SSC design meets the SSE Time History SSE Time History Curve bounds the EPRI GMRS in the range of 1 to 10 Hz Salem screens out of risk evaluation 14

2.1 Ground Motion Response Spectra (GMRS)

Questions?

15