ML061920361
| ML061920361 | |
| Person / Time | |
|---|---|
| Site: | Arkansas Nuclear  |
| Issue date: | 06/30/2006 |
| From: | Entergy Operations |
| To: | Office of Nuclear Reactor Regulation |
| References | |
| Download: ML061920361 (15) | |
Text
- 'Entergy Purpose
" ANO-1 Spent Fuel Pool (SFP) Project
- Metamic Poison Insert Assemblies (PIAs) Design
- ANO-1 Technical Specification (TS) changes and timing
" ANO-2 SFP Project
- Partial Re-rack
- ANO-2 TS changes and timing
" Schedule Constraints 2
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ANO-1 SFP Design
- The ANO-1 SFP is currently divided into Region 1 and Region 2.
- Region 1 contains Boraflex.
- Region 2 does not contain poison materials; fuel assembly storage is restricted in accordance with ANO-1 TS.
- Soluble boron is not credited in ANO-1 criticality analysis.
3 eEntergy ANO-1 SFP Layout Region I Proposed Region 2 Region 2 1Ox 11 Region 3 l x 11 11 x 11 11 x12 Region I Proposed Region 2 Region 2 lOXil 1
Region 3 lIXIl lixiI 11 x12 2
ANO-1 SFP Loading
" Boraflex in Region 1 is degrading.
- August 2002 Region 1 SFP racks were considered operable but degraded as allowed by GL 91-18.
- April 2007 - Credit will no longer be taken for Boraflex resulting in a loss of full core offload capability.
" Current fuel loading strategy includes loading 3 dry casks prior to the spring 2007 refueling outage.
-Enter8y ANO-1 Metamic Project Overview
- To provide an area where unrestricted storage is available, a portion of Region 2 will be defined as Region 3.
" Metamic PIAs will be installed in the existing rack flux traps of Region 3.
" U-235 fuel enrichment will be increased from 4.1wt.% to 5.Owt.% for future core reload flexibility.
- Soluble boron will be credited as allowed by 1 OCFR50.68.
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--* Entergy Metamic Overview Metamic has been approved for use in Fuel Pool applications by NRC letter to Entergy dated June 17, 2003.
Conditions and Limitations of NRC Safety Evaluation include:
- Coupon Sampling Program
- Discussion of coupons
- Description of anodizing process and cleaning techniques (not using anodizing process)
- B4C content less than 31wt.% (using 25wt.%)
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- En tergy ANO-1 Current Project Status
- Criticality analyses have been performed to analyze Region 1 racks with no credit for Boraflex Region 2 racks with no poison insert material Region 3 racks with Metamic PIAs New Fuel Vault and fuel handling equipment
- Structural /seismic for Region 3 racks and pool analyses considering poison insert design and additional weight.
- Thermal hydraulic analysis
- Postulated fuel assembly drop events for Region 3 of SFP racks.
- Evaluation of potential offsite and control room dose radiological consequences of a Fuel Handling Accident (FHA) is currently reflected in the ANO-1 SAR.
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- Enterg, PIA Design sModifications
- Original PIA design, as previously submitted to the NRC, was a collapsible design for insertion and expanded to fill the flux trap.
" Revised PIA design is a non-collapsible fixed design.
--Entergy PIA Design Overview
- PIA length is -13 feet; active fuel length
-12 feet.
- PIA width is 7.12 inches.
- PIA thickness 1.20 inches.
- PIA weight -50 lbs. each.
- External SS sheaths along the full length of the PIA protects the Metamic-panels when inserted in the flux trap.
Bands are located at the ends and four locations along the length.
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t-Entergy Top View of PIA 11
.:.Entffgy Stiffeners 12 126
ý-Entergy PIA Location in Flux Trap 14 7
!ýEnterWj ANO-1 Submittal History Topical Report August 8, 2002 - Entergy submitted Topical Report "Use of Metamic In Fuel Pool Applications."
June 17, 2003 - NRC approves Topical Report.
ANO-1 License Amendment April 2, 2003 - Entergy submitted license amendment to modify spent fuel loading restrictions for Regions 1, 2, and 3.
- June 24, 2004 - Entergy withdrew the license amendment due to the inability to manufacture PIAs to meet the design specifications to support the criticality analysis.
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"*-En t rgy Project Activities The following is a summary of activities performed since the 2004 amendment withdrawal.
The original design concept was reevaluated which resulted in a design change to a non-collapsible, fixed design.
- A comprehensive examination of the spent fuel pool (SFP) racks was performed for additional design input.
Preliminary analyses were performed and two PIAs were manufactured using the fixed design to ensure constructability.
Performance of formal design documentation and analyses for licensing PIAs.
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- Entergy ANO-l Proposed Licensing Amendment License amendment reflects new design and will include the following:
- Storage restrictions for SFP where appropriate.
- Boron credit
- Compliance with 10 CFR 50.68(b).
- Fuel enrichment increased from 4.1wt%. to 5.Owt.%
- Metamic Coupon Sampling Program will be added.
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- Enterj' ANO-1 Submittal Plans
- LAR submitted by July 2006 with approval by January 15, 2007.
- Advantage
-Allows insertions of PIAs in January/February 2007.
-Allows full core offload following outage.
- Disadvantage
- NRC review time shortened.
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-Entergy Other ANO-1 Options Considered Continue to address ANO-1 SFP conditions as degraded with alternate loading scheme
- Requires applying the Region 2 rack analysis to Region 1 under 10 CFR 50.59 using the current licensing basis and accounting for the Boraflex structure without crediting its neutron absorption capability.
- Allows full core offload capability for spring 2007 outage, but not after the outage.
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--- Ent ergy Other ANO-1 Options Considered Insert PIAs in January under 50.59
- Requires analytical confirmation of current licensing basis for:
- Criticality analysis
" Structural analysis
- Allows NRC review time to be extended from January to March 2007.
- Allows full core offload capability when Metamic@
amendment is approved.
- Substantial analysis for short duration.
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AOEn t erP, ANO-2 SFP Project
-Ent ergy ANO-2 Project Overview
- The ANO-2 Spent Fuel Pool (SFP) is currently divided into Region I and Region 2.
- Region 1 racks contain Boraflex that is no longer credited.
- Region 2 racks do not contain poison materials.
- Flux trap dimensions in Region 2 racks prohibit PIA insertion.
Region 1 racks will be replaced with Metamic racks restoring unrestricted fuel assembly storage.
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0- Entergy ANO-2 SFP Layout Region 2 Region 2 Region 2 Region 1 9x9 8x10 9x10 9x9 Region 2 Region 2 Region 2 Region 1 9x9 9x10 9x10 9x9 Region 2 Region 2 Region 2 Region I 8x9 9x10 8x10 8x9 23 Entefrgy ANO-2 Project Overview
- Current loading pattern is complex.
- - 1/2 of fuel assemblies in the core are replaced each cycle. Minimal cooling time is 5 years prior to loading fuel in a dry fuel cask; however time is typically longer.
- Currently, all available fuel is loaded into dry fuel casks.
- More fuel assemblies will be available to load into dry fuel casks by June 2007.
- Window of opportunity (due to other competing SFP activities) for re-rack September - December 2007.
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- Entergy ANO-2 License Amendment History Topical Report
- August 8, 2002 - Entergy submitted Topical Report "Use of Metamic In Fuel Pool Applications."
- June 17, 2003 - NRC approves Topical Report.
ANO-2 License Amendment
- January 29, 2003 - Entergy submitted license amendment to modify spent fuel loading restrictions for Regions 1, 2, and 3.
- August 26, 2003 - Entergy withdrew the license amendment due to extrusion problems.
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-- Entergy Project Activities The following is a summary of activities performed since the 2003 amendment withdrawal.
- Alternate loading pattern TS change submitted and approved.
- The original design concept was reevaluated which indicated that a design similar to AN 0-1 cannot be manufactured for ANO-2 due to the smaller flux trap.
A comprehensive examination of the SFP racks and other designs was performed.
- Partial re-rack resulted in only viable option that results in unrestricted storage.
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--7En terg, ANO-2 Proposed License Amendment The proposed amendment will reflect the partial re-rack and include the following:
- New storage restrictions.
- Increase in fuel enrichment from 4.55wt% to 5.Owt.%.
- Boron credit (ANO-2 currently complies with 1 OCFR50.68(b)).
- Add Metamic Coupon Sampling Program.
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- Enftergy ANO-2 Submittal Plans
- Submit by December 31, 2006
- Requested approval by September 1, 2007.
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ZEntergy Schedule Const raints Common SFP floor and equipment Activities in ANO-1 and ANO-2 SFPs March - April 2006 loaded 3 casks for ANO-2.
May 2006 reconfigured ANO-2 SFP for new fuel receipt and to support criticality analysis for fuel core offload.
June 2006 new fuel receipt ANO-2.
July 2006 load 2 casks for ANO-1.
Sept - Oct. 2006 ANO-2 Refueling Outage.
Nov. 2006 load I cask for ANO-1.
Jan. - February 2007 Insert PIAs in ANO-1 SFP.
March 2007 new fuel receipt and fuel reconfiguration ANO-1.
April2007 - ANO-1 Region I Boraflex no longer credited.
April - May 2007 ANO-1 Refueling Outage.
June 2007 load 2 casks for ANO-2.
July 2007 load 2 casks for ANO-1.
September - December 2007 partial re-rack ANO-2.
Jan/Feb 2008 - New fuel receipt ANO-2.
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-Entergy Summary 0 ANO-1 SFP Project
- Metamic PIAs need to be inserted in the SFP in January / February 2007.
- Unless PIA insertion can be accomplished prior to the approval of the TS, license amendment approval is needed by January 15, 2007.
- ANO-2 SFP Project
- Partial Re-rack
- License amendment approval needed by September 1, 2007.
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