ML053250237

11/1/2005, Presentation from Duke Energy Corp, Oconee, Units 1, 2 and 3, Meeting Summary, Part 72-Licensed Casks in Spent Fuel Pools

ML053250237
Person / Time
Site:	Oconee
Issue date:	11/01/2005
From:	Duke Power Co
To:	Office of Nuclear Reactor Regulation
Olshan L N, NRR/DLPM, 415-1419
Shared Package
ML053250224	List: ML053130120 ML053250237
References
Download: ML053250237 (19)

Text

Part 50 License Amendment Request (LAR) for Dry Storage Loadings at Oconee Presentation to the United States Nuclear Regulatory Commission (NRC)

Rockville, MD November 1, 2005

Purpose z Provide Information to the NRC Concerning:

Dukes suspension of dry storage loadings at Oconee in response to Regulatory Issue Summary (RIS) 2005-05 Dukes LAR to address the RIS 2005-05 issues for Oconee Schedule for the LAR submittal to the NRC and requested approval date z Obtain NRC Feedback Can the NRC Staff support Dukes LAR schedule?

What can Duke do to expedite the review process?

November 1, 2005 2

Duke Representatives z Oconee Nuclear Site Steve Newman - Regulatory Compliance z Nuclear General Office Steve Nesbit - Mgr. Spent Fuel Management Gary Walden - SFM (lead for ONS ISFSI)

Joe Coletta - SFM (criticality analyst)

William Murphy - SFM (criticality analyst)

November 1, 2005 3

Overview z Need for LAR (Nesbit) z Scope (Nesbit) z Technical Approach (Coletta) z Schedule (Walden) z Discussion (ALL) z Closing Remarks (Newman)

November 1, 2005 4

Need for LAR z Dry Fuel Storage Systems at Oconee Soluble Boron Required During Number of License Storage System Loading? Canisters Time Period Site-Specific NUHOMS-24P yes 40 (loaded) 1990-1996 General NUHOMS-24P yes 44 (loaded) 1999-2005 General NUHOMS-24PHB yes 28 (to be loaded) 2005-2009 November 1, 2005 5

Need for LAR z RIS 2005-05 Issued on March 23, 2005 Noted potential inconsistencies between regulatory bases of fuel pools and dry storage 3/4Potential for unanalyzed condition during dry cask loading in the spent fuel pool Stated that affected licensees must meet both Part 50 and Part 72 requirements for cask loading/unloading in the pool 3/4Part 50: credit for burnup is allowed; must show subcriticality in unborated water 3/4Part 72: credit for dissolved boron is allowed for demonstrating subcriticality Suggests Part 50 license amendment for burnup credit November 1, 2005 6

Need for LAR z Actions on RIS 2005-05 Suspended Oconee dry storage loadings planned for June 2005 (suspension in effect until issue resolved)

Entered the issue into Oconees corrective active program Began development of a request for exemption from 10CFR50.68(b)(1)

Changed to LAR approach based on subsequent NRC interactions with other licensees Duke is working through the Nuclear Energy Institute toward a generic resolution of the issue November 1, 2005 7

Scope z New Dry Storage Canister Criticality Analysis New Part 50 LAR Analysis will address current and previously loaded NUHOMS canisters Conform to current NRC expectations for soluble boron credit under Part 50 No change to NUHOMS Part 72 licenses or analyses z No Change to SFP Storage Rack Analyses Maintain current Oconee SFP licensing basis 3/4 Approved by NRC in 2002 3/4 Based on WCAP 14416 November 1, 2005 8

Scope z New Part 50 Technical Specification Establish minimum burnup requirements for fuel to be loaded into dry storage canisters (burnup vs. enrichment curve) z Supporting analyses are being developed by Duke z LAR will be crafted with goal of flexibility to evaluate future dry storage casks via the 50.59 process November 1, 2005 9

Technical Approach z NUHOMS-24P Systems Have Common Basket Design Source: NUHOMS FSAR, Rev. 8, June 2004 November 1, 2005 10

Technical Approach z Roadmap to Fuel Burnup Requirements CASMO-3 2-D Simplified Model Canister Burnup for Criticality Curve Calculation SIMULATE-3 3-D Axial Burnup Bias Calculation SCALE 4.4 / KENO V.a 3-D Detailed Model for Comparison November 1, 2005 11

Technical Approach z Codes Used for Analysis CASMO-3 3/4Base 2-D model calculations 3/4Burnup credit computations

- Reactor depletion D dry storage canister rack calculations with burned fuel SIMULATE-3 3/43-D axial burnup bias determination 3/4Axial bias applied to 95/95 k-eff calculations where positive SCALE 4.4 / KENO V.a 3/43-D full detail canister model with fresh fuel 3/4Used to demonstrate conservatism of CASMO-3 November 1, 2005 12

Technical Approach z Geometric Models 1 representative spacing for infinite lattice (CASMO-3) 3 different fuel assembly spacings (KENO V.a)

November 1, 2005 13

Technical Approach z CASMO-3 Computational Canister Model 2-D infinite lattice Single representative fuel assembly spacing 3/4Conservatism will be demonstrated No axial leakage Full density moderator in dry storage canister 3/4Water temperature between 32oF and 212oF 3/4No moderator in pellet-clad gap Fuel designs: Mark B2-B8; B9; B10; B10L Conservative depletion parameters Credit for 5 years post-irradiation cooling time November 1, 2005 14

Technical Approach z Preliminary Results 45 Curve specifies 40 M inim um A s s e m bly B ur nup minimum burnup 35 based on maximum 30 initial enrichment 25 (GW D /M TU )

20 Single region within 15 dry storage canister 10 5

Applies to all 0 analyzed fuel types 1.5 2 2.5 3 3.5 4 4.5 5 Initial Max. Design Enrichment (wt. % U-235)

Applicable to NUHOMS-24P and NUHOMS-24PHB November 1, 2005 15

Technical Approach z Conservatisms in Analysis Infinite lattice (radial and axial) canister model In-reactor depletion parameters 3/4Boron concentration 3/4Moderator temperature 3/4Discrete BP presence 3/4Fuel temperature Mechanical and burnup-related uncertainties Axial burnup profiles for 3-D bias Most reactive fuel assembly design November 1, 2005 16

Schedule z Prudent Operating Reserve (POR) for Oconee Empty storage cells for core offload during refuel (177)

Storage cells empty of irradiated fuel (168) 3/4 Diver access to repair upender, if needed 3/4 New fuel assemblies stored in these cells z Unit 1/2 Spent Fuel Pool (SFP)

Unit 2 Refuel, Fall 2005: POR not available Unit 1 Refuel, Fall 2006 3/4 Need to load 4 canisters to restore POR 3/4 Need to load 2 canisters to store all new fuel in pool z Unit 3 SFP Unit 3 Refuel, Spring 2006: POR not available Unit 3 Refuel, Fall 2007 3/4 Need to load 3 canisters to restore POR November 1, 2005 17

Schedule z LAR Schedule Submittal to NRC 3/1/06 NRC approval 6/1/06 November 1, 2005 18