ML18067A643
| ML18067A643 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 07/24/1997 |
| From: | Bordine T CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9707300182 | |
| Download: ML18067A643 (8) | |
Text
f A CMS Energy Company July 24, 1997 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT 111oma* t:. BonllDB Manager Licensing SUBMITTAL OF REVISED INSERVICE TESTING VALVE RELIEF REQUEST NUMBERS 30 & 31 On March 5, 1996, Consumers Energy Company submitted its Third Interval lnservice Testing (IST) Program for the Palisades Plant. This interval began on August 21, 1995, following the completion of the Cycle 11 refueling outage. On August 30, 1996, the NRC issued a safety evaluation that, in part, gave interim relief to the requirements to test Relief Valves RV-0401, RV-3162, and RV-3164 in full compliance with the code referenced by 10 CFR 50.55a(b). This interim relief was granted in accordance with 10 CFR 50.55a(a)(3)(ii) based on the hardship or unusual difficulty without a compensating increase in the level of quality and safety that would result if the requirements were imposed. The interim period was granted for the initial 24-month period from the start of the third interval.
The set point for Relief Valve RV-0401 would be required to be verified during the 1998 refueling outage if approval of Valve Relief Request (VRR) No. 30 is not obtained. This would require a full core off load which is not scheduled for this outage. Consumers Energy is therefore requesting approval of VRR No. 30 by December 31, 1997, in order to finalize plans for the 1998 refueling outage.
The set point for either Relief Valve RV-3162 or RV-3164 would be required to be verified prior to August 21, 2001, if approval of VRR No. 31 is not obtained. Again, this would require a full core off load which is not scheduled prior to that time. Consumers Energy is therefore requesting approval of VRR No. 31 by July 15, 1998, in order to properly plan for future outages.
9707300182 970724/ I PDR ADOCK 050002.55 P
PDR'
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J 111111111111111111111111111111111 Ill llll l
- 114889*1 Palisades Nuclear Plant
- 27780 Blue Star Memorial Highway
- Covt:il, Ml 49043
- Tel: 616 764 2913
- Fax: 616 764 2490
The attachment to this letter contains the revised VRR Nos. 30 and 31. These relief requests have been revised to include that information required for approval in accordance with the direction given in the NRC's August 30, 1996, safety evaluation.
The additional information includes historical data on the performance of these valves and information on the plant status under which the valves may be tested.
SUMMARY
OF COMMITMENTS This letter contains no new commitments and no revisions to existing commitments.
Thomas C. Bordine Manager, Licensing CC Administrator, Region Ill, USNRC Project Manager, NRR, USNRC NRC Resident Inspector - Palisades Attachment 2
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ATTACHMENT CONSUMERSENERGYCOMPANY PALISADES PLANT DOCKET 50-255 SUBMITTAL OF REVISED INSERVICE TESTING VALVE RELIEF REQUEST NUMBERS 30 & 31 5 Pages
RELIEF REQUEST BASIS NUMBER30 SYSTEM:
Shutdown Cooling System (M204-1. G-1)
VALVES:
RV-0401 CATEGORY:
c CLASS:
1 FUNCTION:
This valve has a safety function to provide overpressure protection to the Shutdown Cooling return header between valves M0-3015 and M0-3016.
TEST REQUIREMENT:
ASME/ANSI OM-1987, Part 1, Para. 1.3.3.1(b): "All valves of each type and manufacture shall be tested within each subsequent 5 year period with a minimum of 20% of the valves tested within any 24 months."
BASIS FOR RELIEF:
Relief is requested in accordance with 10 CFR 50.55a(f)(5)(iii) from the requirement to perform set point verification on either a 5-year basis or a 24-month basis because such testing is impractical. Relief valve RV-0401 is welded in place and is located in the letdown from the Primary Coolant System to the Shutdown Cooling System. Testing cannot be performed with the Primary Coolant System greater than cold shutdown because RV-0401 provides the second isolation barrier for the PCS. Failure of the first isolation barrier (M0-3015) would result in uncontrollable and highly contaminated PCS leakage.
Testing cannot be performed during cold shutdown with Shutdown Cooling in service because Palisades has no alternate letdown paths for Shutdown Cooling. Shutdown Cooling cannot be isolated unless there is a full core off load. Based on this fact, RV-0401 can only be tested during full core off loads.
A historical review qf set point testing for Teledyne Farris Engineering Safety-Relief Valve Model 2741 PKD/S4 indicates maximum test intervals are dependent on system service conditions. Similar valves in other systems were also reviewed. However, those valves were subjected to more dynamic system pressure fluctuations and vibration caused by reciprocating positive displacement pumps than RV-0401. Relief valves subjected to dynamic loads would typically require shorter set point test intervals than in static systems.
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RELIEF REQUEST BASIS NUMBER 30
- RV-0401 provides overpressure protection to the Shutdown Cooling return header between valves M0-3015 and M0-3016. This portion of the Shutdown Cooling System is static except when providing"core cooling during plant Cold Shutdowns. With more than 10 years of service, historical test data shows RV-0401 set point to have drifted from 2482 psig to 2450 psig. Even with set point drift, system operability and safety requirements were maintained with no reduction of Safety Margin. Therefore, a maximum set point test interval of 1 O years is acceptable for RV-0401.
ALTERNATIVE TESTING:
Consumers Energy will verify RV-0401 set points at least once every 10 years during full core off loads unless testing has been performed in the previous 24 months as required by Technical Specification Surveillance Procedure RT-116, "Miscellaneous Safety Systems Safety Valve Set Point Testing."
QUALIFICATION PROGRAM:
None INSTRUMENTATION DESCRIPTION:
None BASELINE DATA:
None ACCEPTANCE CRITERIA:
At each set point verification, RV-0401 shall meet the set point and seat leakage acceptance criteria required by Techni.cal Specification Surveillance Procedure RT-116.
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RELIEF REQUEST BASIS NUMBER 31
- SYSTEM:
Shutdown Cooling System (M203-2 and M204-1)
VALVES:
RV-3162 and RV-3164 CATEGORY:
c CLASS:
2 FUNCTION:
- 1.
Relief valve RV-3162 has a safety function to provide overpressure protection for the Shutdown Cooling discharge header. Overpressure protection is required due to small amounts of back leakage from the Primary Coolant System.
- 2.
Relief valve RV-3164 has a safety function to provide overpressure protection for the Shutdown Cooling supply line. Overpressure protection is required during Plant heatup and failure in this operating scenario could render the line inoperable during plant cooldown.
TEST REQUIREMENT:
ASME/ANSI OM-1987, Part 1, Para. 1.3.4.1(b): "All valves of each type of manufacture shall be tested within each subsequent 10-year period, with a minimum of 20% of these valves tested within any 48 months.
BASIS FOR RELIEF:
Relief is requested in accordance with 10 CFR 50.55a(f)(5)(iii) from the requirement to perform set point verification on a 48-month basis because such testing is impractical.
The Palisades configuration uses one system for shutdown cooling service and low pressure safety injection. Relief valves RV-3162 and RV-3164 are flanged in place and are located in the discharge and supply lines for the Shutdown Cooling System.
Testing cannot be performed with the reactor critical because removal of these valves from service would render more Low Pressure Safety Injection System components inoperable than allowed by Plant Technical Specifications.
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Q RELIEF REQUEST BASIS NUMBER 31
- Testing during the period between cold shutdown and reactor critical requires the draining of a safety system and the removal of relief valves for set point testing.
Testing cannot be performed during cold shutdown with shutdown cooling in service because these valves are located in non-redundant portions of the Shutdown Cooling System. Palisades has no alternate discharge paths for shutdown cooling and the relief valves cannot be isolated unless there is a full core off load. Based on this fact, RV-316~ and RV-3164 can only be tested during full core off loads.
A historical review of available data of set point testing for RV-3162 and RV-3164, covering 71 months, was conducted. This review shows RV-3162 has remained within set point tolerance for the entire 71 month period. This review also shows the set point for RV-3164 drifted from 300 psig to 285 psig during the same 71 month period. Even with set point drift, system operability and safety.
requirements were maintained with no reduction in Safety Margin. This portion of the Shutdown Cooling System is static except when providing core cooling during plant cold shutdowns. Therefore, RV-3162 and RV-3164 are not exposed to excessive system vibration or pressure fluctuations which contribute to valve wear and set point fluctuation. A maximum set point test interval of 10 years is
- acceptable.
ALTERNATIVE TESTING:
Consumers Energy will verify RV-3162 and RV-3164 set points at least once every 10 years during full core off loads when testing has not been performed in the previous 48 months as required by Technical Specification Surveillance Procedure RT-116, "Miscellaneous Safety Systems Safety Valve Set Point Testing."
QUALIFICATION PROGRAM:
None INSTRUMENTATION DESCRIPTION:
None BASELINE DATA:
None 2
RELIEF REQUEST BASIS NUMBER 31
- ACCEPTANCE CRITERIA:
At each set point verification, RV-3162 and RV-3164 shall meet the set point and seat leakage acceptance criteria required by Technical Specification Surveillance Procedure RT-116.
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