U-600582, Submits Addl Info to Support 851016 Commitment to Comply w/10CFR50.62(c)(4) Re ATWS Requirements for Equivalent Control Capacity,Per Generic Ltr 85-03.Figure 3.1.5.-1 Re Revised Min Sodium Pentaborate Solution Concentration Encl
| ML20198E023 | |
| Person / Time | |
|---|---|
| Site: | Clinton  |
| Issue date: | 05/23/1986 |
| From: | Spangenberg F ILLINOIS POWER CO. |
| To: | Bulter W, Butler W Office of Nuclear Reactor Regulation |
| References | |
| GL-85-03, GL-85-3, U-600582, NUDOCS 8605270224 | |
| Download: ML20198E023 (3) | |
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U-600582 L30-86 (05 -23 )-L 1A.120 ILLINOIS POWER 00MPANY CLINTON POWER STATION. P.o. 80X 678, CLINTON, ILLINOIS 61727 May 23, 1986 Docket No. 50-461 Director of Nuclear Reactor Regulation Attention:
Dr. W. R. Butler, Director BWR Project Directorate No. 4 Division of BWR Licensing U. S. Nuclear Regulatory Commission Washington, DC 20555
Subject:
Clinton Power Station (CPS)
Compliance With 10CFR50.62(c)(4) - ATWS Requirements for Equivalent Control Capacity
Dear Dr. Butler:
Illinois Power (IP) Letter U-600279, dated October 16, 1985, provided a description of how CPS complies with 10CFR50.62,
" Requirements for Reduction of Risk of Anticipated Transients Without Scram (ATWS) Events for Light-Water-Cooled Nuclear Power Plants."
Paragraph (c)(4) of 10CFR50.62 states, in part:
"Each boiling water reactor must have a standby liquid control system (SLCS) with a minimum flow capacity and boron content equivalent in control capacity to 86 gallons per minute of 13-weight percent sodium pentaborate solution."
In the referenced IP letter, IP committed to revise CPS Technical Specification (TS) 3/4.1.5, " Standby Liquid Control System", prior to Fuel Load, to include a minimum 10.0 weight percent (wt.%). This commitment has been fulfilled to satisfy the requirements of NRC Generic Letter (GL) 85-03, " Clarification of Equivalent Control Capacity for Standby Liquid Control Systems." The purpose of this letter is to provide additional information to support a change to this commitment.
The 10.0 wt.% minimum sodium pentaborate concentration previously calculated for CPS was based on a nominal 43 gpm flow rate *for each SLCS pump. This resulted in a CPS TS which included the 10.0 wt.% and the 43 gpm values. The 43 gpm value was chosen based on IP's interpretation of the flow equivalency requirements of GL 85-03. Recent discussions between General Electric, the BWR Owner's Group (BWROG) ATWS Compliance Committee and Mr. M. W. Hodges (NRC/BWRS) have provided additional clarification to these requirements. Based on these discussions and basic agreements reached in followup CPS-specific discussions with Mr.
Hodges and Mr. B. L. Siegel of your staff, the following changes to IP's previous commitment are submitted for final Staff review:
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F '.o U-600582 L30-86 (05-23 )-L 1A.120 1.
CPS TS 3/4.1.5 Minimum SLCS Pump Flow A value of 41.2 gpm, the original TS value for these pumps, will be used in meeting the equivalent control capacity requirement. This value will allow for normal degradation over the life of the pump, such that during TS required surveillance testing the minimum required capacity is not approached.
2.
Minimum Sodium Pentaborate Solution Concentration Using a 41.2 gpm minimum SLCS pump flow, a minimum concentration of 10.2 wt.% is calculated. A copy of CPS TS Figure 3.1.5-1 is attached which implements this revised minimum concentration.
The calculation of the minimum sodium pentaborate solution concentration is based on NRC-accepted relationships presented in NEDE-24222, " Assessment of BWR Mitigation of ATWS, Volumes I and II", dated December 1979.
With these changes, IP continues to fulfill the requirements of 10CFR50.62(c) (4). No additional TS changes are required to implement the ATWS Rule. This is consistent with the BWROG position.
Please contact me following your review of the changes identified herein, if you require additional information relative to IP's commitment on CPS ATWS equivalent control capacity.
Sincerely ours, F. A.
angen g
Manag
- Lie sing and Safety TLR/kaf Attachment cc:
B. L. Siegel, NRC Clinton Licensing Project Manager NRC Resident Office M. W. Hodges, NRC/BWRS Illinois Department of Nuclear Safety Regional Administrator, Region III, USNRC
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17 REGION OF ACCEPTABLE 16
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Figure 3.1.5-1 Weight Percent Sodium Pqntaborate Solution as a Function of Net Tank Volume CLINTON-UNIT l 3/4 1-21