ML050240124
| ML050240124 | |
| Person / Time | |
|---|---|
| Site: | Palo Verde  |
| Issue date: | 12/09/2004 |
| From: | Arizona Public Service Co |
| To: | Office of Nuclear Reactor Regulation |
| Fields M B ,NRR/DLPM,415-3062 | |
| References | |
| Download: ML050240124 (12) | |
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Dry Fuel Storage Update Palo Verde Nuclear Generating Station NRC SFPO Meeting December 9, 2004 I
2003
+ Zero OSHA or lost time
+ Loaded 1 0 casks
- 5 in Unit 2
- 5 in Unit 1 Review injuries Parameters
- Max burnup 42,833 MWD/MTU, 1 1 kW
- Max total dose per canister 535 mR,
- Min total dose per canister 274 mR Vacuum drying routinely required 2 to 3 in-pool cooling periods per Amendment 2 of CoC Numerous procedure and process improvements 2
2004 Review
- Zero OSHA or lost time injuries incurred
+ Loaded 12 casks, developing extra pool space 6 in Unit 3, 6 in Unit 2
- Steady decline in dose received For canister 20, total dose was 95 mR Lowest found in industry, avg lows 242 mR New weld contractor in 2004
- Equipment upgraded to computer controlled Personnel more versatile Implemented UMS CoC Amendment 3 One in-pool cooling period needed during vacuum drying
- Significant time savings aI, \\\\,
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2004 Events
- Experienced 250 gallons water in-leakage
- Single plant Tech Spec violation for siphon of 20 gallons of water from spent fuel pool
- Experienced slight loss of level in cask load pit (evaporation), below top of TFR
+ Procedures didn't require TFR to be submerged per Tech Spec
+ All issues related to in-pool cooling cycles
- Damaged vacuum pump 4
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Vacuum Drying Challenges
+ With CoC Amendment 2 required 2 to 3 LCO entries
+ After CoC Amendment 3 requires only 1 LCO entry
+ With CoC Amendment 4, should be able to meet criteria without LCO entry
+ Each LCO entry represents increased risk I/\\1i/
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Vacuum Dryness
- Horizontal surfaces tend to hold water
+ Fuel design has water traps in dashpots
+ Current criteria is less than 3 mm Hg for 30 minutes
+ Amendment 4 requests criteria of less than 10 mm Hg for 10 minutes Same as NAC MPC criteria as currently approved by NRC
- RAI for Amendment 4 questions pressure rise
- Contributors to pressure rise
- Residual moisture Temperature rise System leaks
- Instrumentation Ia,,
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+ Benefits
- Vacuum drying criteria
- CEA guide tube inserts
- Eliminate seismic criteria
- Current issuance schedule won't support cask loading in 2005
- Starts January, ends August
- Amendment schedule projects August 2005
- RAI issues will require some technical evaluation al 7
- NARL
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Self Audit Results
- No significant problems or program weakness found with the dry cask program
- Strong NFM program ownership noted
'Areas needing improvement
+ PM bases development and implementation
+ Equipment inspection implementation
- Records coding
- All issues have been evaluated, corrective actions are in progress 8
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Operating Experience
+ Utilize nuclear and non-nuclear experience reports
+ Inadvertent canister backfill with Argonne
+ Rail line issues
+ Transportability of MPC vacuum drying concerns to UMS
+ Issue of water collection in MPC VCC base plate during construction
+ VCC concrete spalling S
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2005 Plans
+ Load 12 casks
- 6 in Unit 1, 6 in Unit 3
+ Avg dose goal is 125mR/cask
+ Receive UMS CoC Amendment 4
+ Improve vacuum drying process
- Reduce cask load costs
+ NRC inspection 1st qtr 10
. 9 Future Needs
- Working to establish extra operating cycle of open space in the spent fuel pools
- PVNGS needs to load high burnup fuel by 2007
- Transition to a higher capacity cask by 2007
- CEA disposal option needed 11 r..
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Cask Procurement
+ Anticipate contract award for high capacity cask by June 30, 2005
+ Chosen design to provide the following features:
- Bound PVNGS site parameters
- High burnup fuel to 60,000 MwDIMTU
- Enrichment to 5 wt %
- Placement of CEAs in fuel guide tubes
- Accommodate PVNGS CE 16X16 length
- No licensed cask meets all requirements, 12 F
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