ML020440407
| ML020440407 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 01/07/2002 |
| From: | Pardee C Exelon Generation Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML020440407 (6) | |
Text
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Exelon.
Exelon Generation Company, LLC www.exeloncoTp.com Nuclear LaSalle County Station 2601 North 21"Road Marseilles, IL 61341-9757 January 7, 2002 10CFR50.55a(a)(3)
United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555 LaSalle County Station Unit 2 Facility Operating License No. NPF-18 NRC Docket No. 50-374
Subject:
Request for a One-Time Relief for Unit 2 Safety Relief Valve Testing Until Refueling Outage L2R10 In accordance with 10 CFR 50.55a(a)(3), Exelon Generation Company (EGC), LLC, requests approval of proposed Relief Request RV-13 for use at LaSalle County Station, Unit 2. The basis of the relief request is that the proposed alternative would provide an acceptable level of quality and safety. Relief Request RV-1 3 requests relief from the American Society of Mechanical Engineers / American National Standards Institute, Operation and Maintenance of Nuclear Power Plants, OM-1 987, Part 1 (OM-1) requirement to test a minimum of 20% of Class 1 pressure relief valves within any 24 months. This relief is requested to delay the LaSalle County Station, Unit 2 Safety Relief Valve (SRV) setpoint testing from October 2004 until the Unit 2 refueling outage, L2R10, currently scheduled for January 15, 2005.
We request that the proposed relief request be approved by September 30, 2002 in order to facilitate outage preparation activities.
Should you have any questions concerning this letter, please contact Mr. William Riffer, Regulatory Assurance Manager, at (815) 415-2800.
Respectfully, harles G. Pardee Site Vice President LaSalle County Station Attachment cc:
Regional Administrator - NRC Region III NRC Senior Resident Inspector - LaSalle County Station
ATTACHMENT VALVE RELIEF REQUEST RV-13
Valve Relief Request - RV-13 Rev. 0 Component Identification Class 1 Code Class:
Reference:
American Society of Mechanical Engineers / American National Standards Institute, Operation and Maintenance of Nuclear Power Plants, OM-1 987, Part 1 (OM-1).
Examination Category:
C
==
Description:==
OM-1 requires Class 1 pressure relief valves be setpoint tested.
Affected Components:
Equipment Part Number:
2B21 -F013C 2B21-F013D 2B21-FO13E 2B21-F013F 2B21 -F01 3H 2B21-F013K 2B21 -F01 3L 2B21 -F01 3M 2B21-FO13P 2B21 -F013R 2B21-F013S 2B21-F013U 2B21-FO13V
==
Description:==
Unit 2 C Main Steam Safety Relief Valve Unit 2 D Main Steam Safety Relief Valve Unit 2 E Main Steam Safety Relief Valve Unit 2 F Main Steam Safety Relief Valve Unit 2 H Main Steam Safety Relief Valve Unit 2 K Main Steam Safety Relief Valve Unit 2 L Main Steam Safety Relief Valve Unit 2 M Main Steam Safety Relief Valve Unit 2 P Main Steam Safety Relief Valve Unit 2 R Main Steam Safety Relief Valve Unit 2 S Main Steam Safety Relief Valve Unit 2 U Main Steam Safety Relief Valve Unit 2 V Main Steam Safety Relief Valve Code Requirements American Society of Mechanical Engineers / American National Standards Institute, Operation and Maintenance of Nuclear Power Plants, OM-1987, Part 1 (OM-1), Section 1.3.3.1(b) requires a minimum of 20% of Class 1 pressure relief valves be setpoint tested within any 24 months. OM-1 Section 1.3.3.1(e)(1) sets sample expansion criteria beyond the minimum 20% sampling for any valves not meeting acceptance criteria.
Code Requirements From Which Relief is Requested Relief is requested from the OM-1 Code requirements to test a minimum of 20% of Class 1 pressure relief valves within any 24 months for LaSalle County Station, Unit 2. This one-time relief is requested to delay Unit 2 SRV testing from October 2004 until the Unit 2 refueling outage, L2R10, currently scheduled for January 15, 2005. The basis of the relief request is that the proposed alternative would provide an acceptable level of quality and safety.
Basis For Relief LaSalle County Station, Unit 2, is scheduled to setpoint test Safety Relief Valves (SRVs) in refueling outage L2R09, currently scheduled to begin January 10, 2003. The testing is needed to satisfy the code requirement that a minimum of 20% of the SRVs be setpoint tested within any 24 months.
However, LaSalle County Station, Unit 2, will replace 100% of its SRVs during the upcoming planned maintenance outage L2P01, currently scheduled to start on March 30, 2002. This recently planned outage is being conducted as a proactive measure to improve the reliability of these valves. The purpose of the replacement is to install a full complement of pre-tested SRVs that have undergone a seat design change for improved leak tightness. As a result of this maintenance outage, the setpoint testing for the next 20% sample of this group of valves would be required within 24 months. Accounting for a 1.25 extension factor from Technical Specification Surveillance Requirement 3.0.2 (i.e., 30 months) this testing would be required by October 2004. The October 2004 date is between the currently planned refueling outage dates for L2R09 ( January 10, 2003) and L2R1O (January 15, 2005). This relief request proposes to delay the 20%
SRV setpoint testing until refueling outage L2R10. This will result in an extension of the maximum allowed testing frequency from 30 months to approximately 33 months.
A review of as-found SRV setpoint testing history of LaSalle County Station, Units 1 and 2, demonstrates proven relief pressure reliability. There have been 178 SRV setpoint tests performed in the history of the station with only 20 setpoint test failures based on the +/-3% setpoint acceptance criteria. Most of the failed tests (i.e., 18 of the 20 tests) were caused by the valves relieving at lower than their design setpoints (i.e.,
conservative failure). For the 2 remaining setpoint test failures, the valves relieved higher than their design setpoints (i.e., non-conservative failure). The proposed one time extension of the SRV testing frequency to approximately 33 months is not expected to affect the proven relief pressure reliability of these valves.
LaSalle County Station, Unit 2, refueling outage L2R09 is currently planned for January 10, 2003. This is only 10 months after the maintenance outage L2P01 (March 30, 2002) in which 100% of the SRVs are being replaced with pre-tested valves. As a result,
LaSalle County Station is proposing not to test any Unit 2 SRVs during refueling outage L2R09. This is based on the following.
"* LaSalle County Station does not expect the short duration of this relief to affect the setpoint performance of these SRVs based on the setpoint testing history described above.
"* LaSalle County Station has 8% excess relief capacity installed. This excess capacity is sufficient to bound any unexpected setpoint drift that could reasonably be postulated.
"* Shutdown risk in the area of decay heat removal is increased when SRVs are taken out of service. There are times during the L2R09 outage when the shutdown risk could stay at status Green instead of turning to status Yellow for one or two days if SRV work could be avoided.
Thus, not performing SRV setpoint testing during L2R09 will allow greater flexibility in performing outage work.
This relief request proposes to delay the setpoint testing of 20% of the Unit 2 SRVs installed in L2P01 from October 2004 until refueling outage L2R10 (January 15, 2005).
This will result in an extension of the maximum allowed SRV setpoint testing frequency from 30 months to approximately 33 months. This request is based on the following.
"* SRV setpoint testing can only be performed with the unit in an extended maintenance or refueling outage.
LaSalle County Station is not planning any extended Unit 2 maintenance outages between refueling outages L2R09 and L2R10. The performance of an extended maintenance outage solely to perform SRV setpoint testing would subject the unit to an extra transient.
"* LaSalle County Station does not expect this approximate 3-month extension to affect the setpoint performance of these SRVs based on the setpoint testing history described above.
"* LaSalle County Station, Unit 2, will perform setpoint testing on a minimum of 40%
of the SRVs during L2R10. This is twice the SRV setpoint testing that is required by the OM-1 Code to be performed during a 24 month period.
"* LaSalle County Station, Unit 2, will perform setpoint testing on any SRV not tested during L2R1 0 as part of the initial sample and any necessary sample expansion, in refueling outage L2R1 1. This will ensure that every Unit 2 SRV is tested within the Code requirements.
"* The SRVs are passive during normal operation and are only challenged during certain transients.
Therefore, this proposed relief request provides an acceptable level of quality and safety.
Proposed Alternative LaSalle County Station, Unit 2, proposes in lieu of the OM-1 Code requirements to test a minimum of 20% of the SRVs within any 24 months, to perform the following.
"* LaSalle County Station, Unit 2 will replace 100% of its SRVs with pre-tested valves in maintenance outage L2P01, currently scheduled to start on March 30, 2002.
"* LaSalle County Station, Unit 2 will not test any SRVs during refueling outage L2R09, currently schedule for January 10, 2003.
"* LaSalle County Station, Unit 2 will perform setpoint testing on a minimum of 40% of the SRVs during L2R10 currently schedule for January 15, 2005. This is twice the minimum SRV setpoint testing that is required by the OM-1 Code to be performed during a 24 month period.
"* LaSalle County Station, Unit 2 will perform setpoint testing on any SRV not tested during L2R10 (January 15, 2005) as part of the initial sample and any necessary sample expansion, in refueling outage L2R1 1. This will ensure that every Unit 2 SRV is tested within the Code requirements.
Applicable Time Periods The one-time relief is requested to delay LaSalle County Station, Unit 2 SRV testing from October 2004 until the Unit 2 refueling outage, L2R1 0, currently scheduled for January 15, 2005.