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 10CFR50.68.
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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)
- B4 C content less than 31wt.% (using 25wt.%)
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- Entergy 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.
- Internal SS sheathing bands secure the Metamic panels to the external sheath.
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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"*-Ent 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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---Entergy 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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terP, AOEn 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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-- 7Enterg, 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 10CFR50.68(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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