ML062970430
| ML062970430 | |
| Person / Time | |
|---|---|
| Site: | LaSalle  |
| Issue date: | 09/29/2006 |
| From: | Landahl S Exelon Generation Co, Exelon Nuclear |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| RA-06-54 | |
| Download: ML062970430 (14) | |
Text
Exelrn, Exelon Generation Company, LLC www.exeloncorp.com N
e LaSalle County Station NUear 2601 North 21"Road Marseilles, IL 61341-9757 RA-06-54 10 CFR 50.55a September 29, 2006 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 LaSalle County Station, Units 1 and 2 Facility Operating License Nos. NPF-1 1 and NPF-1 8 NRC Docket Nos. 50-373 and 50-374
SUBJECT:
Proposed Third Ten-year Interval Inservice Testing Relief Requests Pursuant to 10 CFR 50.55a, "Codes and standards," paragraphs 10 CFR 50.55a(a)(3)(i) and 10 CFR 50.55a(a)(3)(ii), Exelon Generation Company, LLC (EGC), requests NRC approval of the relief requests, listed below, for the Third Ten-year Inservice Testing Program. The details of the specified relief requests are attached.
RP-01; 'Water Leg Pump Flow Test" RP-02; 'Water Leg Pump Comprehensive Testing" RV-01; "Main Steam Line Safety Relief Valve Post Installation Actuation" RV-02; "Utilization of ASME Code Case OMN-1" EGC requests approval of these requests by October 11, 2007, based on the end date of the Second Inservice Testing Interval. Note that this date includes a one-year extension of the Second Interval as allowed by American Society of Mechanical Engineers (ASME)Section XI, "Inservice Inspection of Nuclear Power plant Components," paragraph IWA-2430, Inspection Intervals, specifically IWA-2430(c).
If you have any questions or require additional information, please contact Mr. Terrence Simpkin, Regulatory Assurance Manager, at 815-415-2800.
Respectfully, Susan Landahl Site Vice President LaSalle County Station Attachments: RP-01; Water Leg Pump Flow Test RP-02; Water Leg Pump Comprehensive Testing RV-01; Main Steam Line Safety Relief Valve Post Installation Actuation RV-02; Utilization of ASME Code Case OMN-1
/4o (7
Attachment Pump Relief Request - RP-01 Water Leg Pump Flow Test (Revision 0)
(Page 1 of 2)
Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety
- 1. ASME Code Component(s) Affected Pump Description Class Category Unit 1 E22-C003 HPCS Water Leg Pump 2
Group A 1
1 E21 -C002 LPCS Water Leg Pump 2
Group A 1
1 El 2-C003 RHR Water Leg Pump 2
Group A 1
1 E51 -C003 RCIC Water Leg Pump 2
Group A 1
2E22-C003 HPCS Water Leg Pump 2
Group A 2
2E21 -C002 LPCS Water Leg Pump 2
Group A 2
2E12-C003 RHR Water Leg Pump 2
Group A 2
2E51 -C003 RCIC Water Leg Pump 2
Group A 2
2. Applicable Code Edition and Addenda
ASME OM Code 2001 Edition through 2003 Addenda
3. Applicable Code Requirement
ISTB-5121, Table ISTB-3000-1; Group A pump quarterly flow tests
4. Reason for Request
The primary purpose of these pumps is to maintain the HPCS, LPCS, RCIC, and RHR pump discharge lines filled to limit the potential for water hammer upon associated pump initiation. Once the supported pump (e.g., HPCS, RHR, etc.) is in operation, the associated water leg pump serves no further safety related function. The amount of flow delivered by each water leg pump is dependent upon each supported systems leakage rate. Each water leg pump is capable of delivering approximately 50 gpm. None of the listed water leg pumps have instrumentation installed in their discharge lines for measuring flow rates.
While flow measurement instrumentation is provided downstream of the water leg pumps branch connection to its associated support system, during power operation the water leg pump is unable to generate sufficient pressure to flow through the associated flow element into the reactor vessel. Even if the water leg pump was capable of developing a head sufficient to inject into the reactor vessel during power operation, the flow measurement instrumentation, which is designed to measure flow developed by either a HPCS (0-8000 gpm), LPCS (0-10,000 gpm), RHR (0-10,000 gpm) or RCIC (0-700 gpm) pump, is not capable of measuring such small flows developed by a water leg pump (i.e., approximately 50 gpm.)
Attachment Pump Relief Request - RP-01 Water Leg Pump Flow Test (Revision 0)
(Page 2 of 2)
The application of temporary flow instrumentation (ultrasonic) cannot be utilized, as there does not exist a run of piping long enough that would allow for an accurate measurement.
System modifications to provide test measuring locations places undue burden on the licensee without demonstrating any increase in the level of plant safety. These pumps are in continuous operation and pump performance is continuously monitored by a low-pressure alarm on each HPCS, LPCS, RHR, and RCIC pump header.
5. Proposed Alternative and Basis for Use
LaSalle County Station will continue to monitor the subject pumps for degradation by measuring and recording pump inlet pressure, discharge pressure, (from which differential pressure is calculated), and vibration. The differential pressure and vibration data will be trended. These measurements are taken quarterly during normal plant operation, when the supported system's pump is not in operation and RCS pressure is greater than the water leg pumps discharge pressure. Measurement and trending of these parameters under these stated conditions will provide satisfactory indication of operational readiness as well as the ability to detect potential degradation. In addition, the main ECCS pump headers each have a low pressure senor which continuously monitors the operability of the respective water leg pump and alarm upon reaching their low setpoints. Station Technical Specification Surveillance Requirements (i.e., TS 3.5.1.1, 3.5.2.3 and 3.5.3.1) also verify operability of the water leg pumps by verifying flow through a high point vent on a monthly basis.
Vibration measurement will continue to be obtained under normal operating conditions and evaluated in accordance with ISTB-5121 (d) and (e). The differential pressure across the pump will also continue to be determined quarterly through plant procedures utilizing each pumps minimum flow line in accordance with ISTB-5121(c) and (e). Differential Pressure and vibration will continue to be trended.
In addition, LaSalle County Station verifies operability of these pumps through the continuous monitoring of the HPCS, LPCS, RHR and RCIC pump discharge line pressures that are monitored in the control room by alarm.
6. Duration of Proposed Alternative
This proposed alternative will be utilized for the entire third 120 month interval.
7. Precedents
This relief request was previously approved for the second ten-year interval at LaSalle County Station Units 1 and 2 as Relief Request RP-01, documented in a Safety Evaluation and Letter dated July 6, 1998.
Attachment Pump Relief Request - RP-02 Water Leg Pump Comprehensive Test (Revision 0)
(Page 1 of 3)
Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(ii)
Hardship or Unusual Difficulty without Compensating Increase in Level of Quality and Safety
- 1. ASME Code Component(s) Affected Pump Description Class Category Unit 1 E22-C003 HPCS Water Leg Pump 2
Group A 1
1 E21 -C002 LPCS Water Leg Pump 2
Group A 1
1 E12-C003 RHR Water Leg Pump 2
Group A 1
1 E51 -C003 RCIC Water Leg Pump 2
Group A 1
2E22-C003 HPCS Water Leg Pump 2
Group A 2
2E21-C002 LPCS Water Leg Pump 2
Group A 2
2E12-C003 RHR Water Leg Pump 2
Group A 2
2E51 -C003 RCIC Water Leg Pump 2
Group A 2
2. Applicable Code Edition and Addenda
ASME OM Code 2001 Edition through 2003 Addenda
3. Applicable Code Requirement
ISTB-5121, Table ISTB-3000-1; Group A pump quarterly flow tests
4. Reason for Request
The primary purpose of these pumps is to maintain the HPCS, LPCS, RCIC, and RHR pump discharge lines filled to limit the potential for water hammer upon associated pump initiation. Once the supported pump (e.g., HPCS, RHR, etc.) is in operation, the associated water leg pump serves no further safety related function. The amount of flow delivered by each water leg pump is dependent upon each supported systems leakage rate. Each water leg pump is capable of delivering approximately 50 gpm. None of the listed water leg pumps have instrumentation installed in their discharge lines for measuring flow rates.
While flow measurement instrumentation is provided downstream of the water leg pumps branch connection to its associated support system, during power operation the water leg pump is unable to generate sufficient pressure to flow through the associated flow element into the reactor vessel. Even if the water leg pump was capable of developing a head sufficient to inject into the reactor vessel during power operation, the flow measurement instrumentation, which is designed to measure flow developed by either a HPCS (0-8000 gpm), LPCS (0-10,000 gpm), RHR (0-10,000 gpm) or RCIC (0-700 gpm) pump, is not capable of measuring such small flows developed by a water leg pump (i.e., approximately 50 gpm.)
Attachment Pump Relief Request - RP-02 Water Leg Pump Comprehensive Test (Revision 0)
(Page 2 of 3)
The application of temporary flow instrumentation (ultrasonic) cannot be utilized, as there does not exist a run of piping long enough that would allow for an accurate measurement.
The Quarterly Group A testing as modified by LaSalle Pump Relief Request RP-01 will continue to be performed during the stipulated conditions that the RCS pressure is greater than the discharge pressure of the associated water leg pump, and that the supported system pump is not in operation during the testing of the associated water leg pump.
Comprehensive Pump testing prescribes that pump parameters are measured while the pump is operating at a flowrate within 20% of the pumps design flow. These water leg pumps do not have a safety related design flow rate. These pumps operate in a "keep ready" mode, maintaining the supported systems piping pressurized with water, which is dependent upon each individual systems leakage rate.
The remaining differences between Comprehensive Pump Testing and Group A testing is the accuracy of the instruments used in measuring the differential pressure (Table ISTB-33500-1) as well as the acceptance criteria associated with the pumps differential pressure (Table ISTB-5100-1 ).
These water leg pumps are tested quarterly by isolating them from their support system piping and measuring their pressure and vibration parameters as they flow through their minimum flow line, through a minimum flow orifice. As there is no flow measurement taken as a result of the system configuration, variation of the system resistance is not used.
The utilization of more accurate test instrumentation and acceptance criteria under these conditions would result in hardship without a compensating increase in the level of quality or safety.
5. Proposed Alternative and Basis for Use
LaSalle County Station will continue to monitor the subject pumps for degradation by measuring and recording pump inlet pressure, discharge pressure, (from which differential pressure is calculated), and vibration. The differential pressure and vibration data will be trended as directed by ISTB-5121 (Group A Test Procedure) as amended by Relief Request RP-01. These measurements are taken quarterly during normal plant operation, when the supported system's pump is not in operation and RCS pressure is greater than the water leg pumps discharge pressure. Measurement and trending of these parameters under these stated conditions will provide satisfactory indication of operational readiness as well as the ability to detect potential degradation.
In addition, the main ECCS pump headers each have a low pressure senor which continuously monitors the operability of the respective water leg pump and alarm upon reaching their low setpoints. Station Technical Specification Surveillance Requirements (i.e., TS 3.5.1.1, 3.5.2.3 and 3.5.3.1) also verify operability of the water leg pumps by verifying flow through a high point vent on a monthly basis.
Vibration measurement will continue to be obtained under normal operating conditions and evaluated in accordance with ISTB-5121(d) and (e) (Group A Testing). The differential
Attachment Pump Relief Request - RP-02 Water Leg Pump Comprehensive Test (Revision 0)
(Page 3 of 3) pressure across the pump will also continue to be determined quarterly through plant procedures utilizing each pumps minimum flow line in accordance with ISTB-5121(c) and (e). Differential Pressure and vibration will continue to be trended.
In addition, LaSalle County Station verifies operability of these pumps through the continuous monitoring of the HPCS, LPCS, RHR and RCIC pump discharge line pressures that are monitored in the control room by alarm.
Comprehensive testing is not applicable as these pumps do not provide a safety related function beyond providing for the readiness of their supported system's pump and thus have no acceptance criteria for a comprehensive test.
6. Duration of Proposed Alternative
This proposed alternative will be utilized for the entire third 120 month interval.
Attachment Valve Relief Request - RV-01 Main Steam Line Safety Relief Valve Post Installation Actuation (Revision 0)
(Page 1 of 3)
Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(i)
Alternative Provides Acceptable Level of Quality and Safety
- 1. ASME Code Component(s) Affected Valve Description Class Category Unit 1B21-F013C C Main Steam Line Safety Relief Valve*
1 C
1 1B21-FO13D B Main Steam Line Safety Relief Valve*
1 C
1 1821-FO13E C Main Steam Line Safety Relief Valve*
1 C
1 1B21-FO13F B Main Steam Line Safety Relief Valve 1
C 1
1 B21 -FO1 3H D Main Steam Line Safety Relief Valve 1
C 1
1821-F7013K B Main Steam Line Safety Relief Valve 1
C 1
1B21-FO13L C Main Steam Line Safety Relief Valve 1
C 1
1B21-FO13M B Main Steam Line Safety Relief Valve 1
C 1
1 B21-FO13P A Main Steam Line Safety Relief Valve 1
C 1
1 B21 -F01 3R C Main Steam Line Safety Relief Valve*
1 C
1 18B21-FO13S B Main Steam Line Safety Relief Valve*
1 C
1 1821-FO1 3U D Main Steam Line Safety Relief Valve*
1 C
1 1B21 -F01 3V A Main Steam Line Safety Relief Valve*
1 C
1 2B21-FO13C C Main Steam Line Safety Relief Valve*
1 C
2 2821-F013D B Main Steam Line Safety Relief Valve*
1 C
2 2B21-F013E C Main Steam Line Safety Relief Valve*
1 C
2 2B21-F013F B Main Steam Line Safety Relief Valve 1
C 2
2B21-FO13H D Main Steam Line Safety Relief Valve 1
C 2
2B21-FO13K B Main Steam Line Safety Relief Valve 1
C 2
2B21-F013L C Main Steam Line Safety Relief Valve 1
C 2
2B21-FO13M B Main Steam Line Safety Relief Valve 1
C 2
2B21-F013P A Main Steam Line Safety Relief Valve 1
C 2
2B21-F013R C Main Steam Line Safety Relief Valve*
1 C
2 2821-FO13S B Main Steam Line Safety Relief Valve*
1 C
2 2B21-F013U D Main Steam Line Safety Relief Valve*
1 C
2 2121-F013V A Main Steam Line Safety Relief Valve*
1 C
2
- - Indicates that the subject valve is also equipped with an Automatic Depressurization System (ADS)
2. Applicable Code Edition and Addenda
ASME OM Code 2001 Edition through 2003 Addenda
Attachment Valve Relief Request - RV-01 Main Steam Line Safety Relief Valve Post Installation Actuation (Revision 0)
(Page 2 of 3)
3. Applicable Code Requirement
Mandatory Appendix I, 1-3410(d), that each valve that has been removed for maintenance and testing and reinstalled shall be remotely actuated at reduced or normal system pressure to verify open and close capability of the valve before resumption of electric power generation.
4. Reason for Request
Currently, approximately 50% of the Main Steam Line Safety/Relief Valves (S/RVs), with Automatic Depressurization System (ADS), and approximately 50% of the S/RV's, without ADS, are removed from the plant and setpoint tested during each refueling outage. The setpoint testing program includes the manual actuation of the S/RV valves and actuators through the bench-test valve control system. Prior to June 15, 2001, after re-installation into the plant, each valve was actuated a second time by the plant installed remote manual actuation equipment per Code requirements.
Prior to June 15, 2001, experience at LaSalle County Station, Unit 1 and Unit 2, as well as else where in the nuclear industry, had shown that repeated manual actuation of the S/RVs can lead to valve through seat leakage during plant operation. During previous operating cycles for LaSalle Unit 1 and Unit 2, approximately 18% (i.e., 5 of 28) of the valves that were subjected to a single insitu open/close cycle developed undesirable through seat leakage, whereas, approximately 57% (i.e., 12 of 21) of the valves that experienced more than one insitu open/close cycle developed undesirable through seat leakage.
During power operation, S/RV through seat leakage is directed to the primary containment suppression pool resulting in either the need for increased cooling of the suppression pool or a plant shutdown in order to fix the leaking valve.
Since December 13, 2001, when the NRC initially approved this Relief Request, LaSalle Unit's 1 and 2 have not had a single instance of through seat leakage that has resulted in the need for immediate corrective actions that involved a loss of operating capacity.
5. Proposed Alternative and Basis for Use
The remote actuation of the Main Steam S/RVs, which have previously been removed for maintenance or refurbishment and replaced, shall be performed in two separate steps. The manual actuation of each valve by its actuator will be performed by the bench-test valve control system of the setpoint testing program.
This will verify the opening and closing of the valve by it's actuator. The plant installed manual actuation equipment will then be tested after valve has been reinstalled into the plant, with the valve stem uncoupled from the actuator.
This will allow for the testing of the plant installed manual actuation electrical circuitry, manual actuation solenoid and air control valve, and the actuator without causing the valve to open.
As a result, all the components of the S/RV, both with and without ADS, will continue to be tested.
Attachment Valve Relief Request - RV-01 Main Steam Line Safety Relief Valve Post Installation Actuation (Revision 0)
(Page 3 of 3)
This uncoupled actuator test will also be performed following any maintenance activity performed on the control circuitry/equipment that could affect the relief mode of the associated S/RV or ADS valves.
As originally stated in NUREG-1482, "Guidelines for Inservice Testing at Nuclear Power Plants," Section 4.3.4, Revision 0, and NUREG-0626, "Generic Evaluation of Feedwater Transients and Small Break Loss-of-Coolant Accidents in GE-Designed Operating Plants and Near-Term Operating License Applications," the NRC staff recommends reducing the number of challenges to the ADS valves.
NUREG-1482, Revision 1, Section 4.3.2.1 references how several licensees have determined that in situ testing of the S/RVs can contribute to undesirable seat leakage of the valve during subsequent plant operation.
Safety/Relief Valve (with or without ADS) which were either maintained or refurbished in place will continue to be tested per the requirements of 1-3410(d).
6. Duration of Proposed Alternative
This proposed alternative will be utilized for the entire third 120-month interval.
7. Precedents
This relief request was previously approved for the second ten-year interval at LaSalle County Station Units 1 and 2 as Relief Request RV-1 1, documented in Safety Evaluation and Letter dated December 13, 2001.
Attachment Valve Relief Request - RV-02 Utilization of ASME Code Case OMN-1 (Revision 0)
(Page 1 of 5)
Proposed Alternative in Accordance with 10 CFR 50.55a(a)(3)(i)
Alternative Provides Acceptable Level of Quality and Safety
- 1. ASME Code Component(s) Affected All ASME Class 1, 2 and 3 Motor Operated Valves (MOV) scoped into the LaSalle County Station Inservice Testing Program subject to diagnostic testing per Generic Letter (GL) 96-05, "Periodic Verification of Design-Basis Capability of Safety-Related Power-Operated Valves," and can not be classified as Skid Mounted.
2. Applicable Code Edition and Addenda
ASME OM Code 2001 Edition through 2003 Addenda
3. Applicable Code Requirement
ISTC, excluding ISTC-3600, Testing of Valves, including MOVs
4. Reason for Request
Pursuant to 10 CFR 50.55a, "Codes and Standards," paragraph (a)(3), relief is requested from the requirements of ISTC-3521 and ISTC-5120.
The proposed alternative would provide an acceptable level of quality and safety.
5. Proposed Alternative and Basis for Use
The Nuclear Regulatory Commission (NRC) in a September 22, 1999 Federal Register Notice (64 FR 51370), issued a Final Rule on 10 CFR Part 50, "Industry Codes and Standards; Amended Requirements." In the final rule, the NRC amended its regulations to incorporate by reference the 1995 Edition and 1996 Addenda of the ASME Code for Operation and Maintenance of Nuclear Power Plants. The final rule also permits the use of alternate rules for IST of MOVs as described in ASME Code Case OMN-1 in lieu of certain provisions of Subsection ISTC.
In the latest (last revised October 31, 2005) issuance of 10 CFR 50.55a, 10 CFR 50.55(a)(b) states in part, that Regulatory Guide 1.192, "Operating and Maintenance Code Case Acceptability, ASME Code," (June 2003), has been approved for incorporation by reference by the Director of the Office of the Federal Register pursuant to 5 U.S.C. 552(a) and 1 CFR Part 51.
In Regulatory Guide 1.192, it states within Table 2, "Conditionally Acceptable OM Code Cases," that the alternative rules of ASME Code Case OMN-1 Revision 0, when applied in conjunction with the provisions for leakage rate testing in ISTC-3600, may be applied with the following provisions:
Attachment Valve Relief Request - RV-02 Utilization of ASME Code Case OMN-1 (Revision 0)
(Page 2 of 5)
- 1. The adequacy of the diagnostic test interval for each valve must be evaluated and adjusted as necessary but not later than five years or three refueling outages (whichever is longer) from initial implementation of ASME Code Case OMN-1.
- 2. When extending the exercise test intervals for high risk MOVs beyond a quarterly frequency, licensees must ensure that the potential increase in core damage frequency and risk associated with the extension is small and consistent with the intent of the Commission's Safety Goal Policy Statement.
- 3. When applying risk insights as part of the implementation of OMN-1, licensees must categorize MOVs according to the their safety significance using the methodology described in Code Case OMN-3, "Requirements for Safety Significance Categorization of Components Using Risk Insights for Inservice Testing of LWR Power Plants," with the conditions discussed in this regulatory guide or use other MOV risk-ranking methodologies accepted by the NRC on a plant-specific or industry-wide basis with the conditions in the applicable safety evaluations.
This conditional acceptance of OMN-1 per Regulatory Guide 1.192 is applicable in lieu of the provisions for stroke-time testing in Subsection ISTC of the 1995 Edition up to and including the 2000 Addenda of the ASME OM Code.
LaSalle County Station proposes to use the requirements of Code Case OMN-1 for MOV stroke time testing and position indication testing.
The LaSalle County Station MOV testing program has been developed utilizing GL 89-10, "Safety Related Motor Operated Valve Testing and Surveillance," and GL 96-05, "Periodic Verification of Design Basis Capability of Safety Related Motor Operated Valves."
The continued implementation of OMN-1 will continue to reconcile and consolidate testing within the IST program and eliminate unnecessary testing that provides minimal information about MOV operational readiness.
As part of LaSalle County Station's commitment on MOV Periodic Verification Testing made in response to GL 96-05, LaSalle is participating in the Joint Owners Group (JOG)
Program for MOV Periodic Verification.
This program is described in Topical Report MPR-1807, Revision 2 and was endorsed by the NRC in an October 1997 Safety Evaluation.
LaSalle County Station implementation and compliance with the above-identified provisions (Items 1-3) of Code Case OMN-1 are detailed below.
- 1.
LaSalle County Station MOV test frequencies identified in the IST program do not exceed three refueling cycles (i.e., a nominal six years).
Therefore, the expectation that frequency of testing be evaluated and adjusted within five years or three refuel outages, whichever is longer, of OMN-1 implementation will be satisfied.
Attachment Valve Relief Request - RV-02 Utilization of ASME Code Case OMN-1 (Revision 0)
(Page 3 of 5)
- 2.
LaSalle will exercise medium and low safety significant MOVs at least once every refuel cycle as required in Code Case OMN-1 Section 3.6.1.
Initially, LaSalle County Station commits to continue to test high risk MOVs quarterly (where it is not practicable to exercise a valve during plant operations, the valve will be exercised in cold shutdown or in refuel outages per OMN-1 Section 3.6.3). When extending the exercise test intervals for high risk MOVs beyond a quarterly frequency, LaSalle County Station shall ensure that any potential increase in the core damage frequency and risk associated with the extension is small and consistent with the intent of the Commission's Safety Goal Policy Statement.
Upon extension of these frequencies, the IST Program will be appropriately revised.
- 3.
LaSalle County Station has performed differential pressure testing practicability reviews for GL 89-10 that evaluated the benefits of performing a particular test against the potential adverse effects placed on the valves or systems caused by this testing.
The evaluation included an assessment of potential component (valve or pump) damage or system availability concerns that may outweigh benefits of dynamic testing for some MOVs. As a result, some MOVs are not subject to differential pressure testing, but are justified for design basis performance by analysis.
This methodology has previously been accepted by the NRC as evident by their approval of LaSalle County Station's initial OMN-1 Relief Request RV-14 for the second IST Interval, approved on November 21, 2002.
Exceptions to OMN-1 With LaSalle County Station compliance with the above provisions as stipulated in RG 1.192, LaSalle County Station requests relief from the following OMN-1 section and proposes the following alternative.
OMN-1 Section 3.3(b) requires inservice tests to be conducted in the as-found condition.
LaSalle County Station proposes not to perform as-found testing in all situations.
Not performing as-found testing is justified by the manner in which we determine MOV functional margin and test interval. Unlike the example for determining test interval given in OMN-1 Section 6.4.4, LaSalle County Station uses a process which is less dependent on as-found testing.
When pre-service testing is performed, a degradation factor is applied to extrapolate the appropriate test frequency based on a calculated decline in functional margin over time. Random selections of valves are as-found tested, and test results are used to validate degradation assumptions per JOG guidelines.
This sample as-found testing is applied to computational methods used to ensure that the functional margin is adequate over the testing 'interval.
Therefore, LaSalle County Station requests relief from the requirement to always perform as-found testing, and will follow the commitments to GL 96-05 to perform some as-found tests.
Attachment Valve Relief Request - RV-02 Utilization of ASME Code Case OMN-1 (Revision 0)
(Page 4 of 5)
Technical Position The following positions describe how LaSalle County Station interprets and complies with the various requirements of OMN-1.
- 1.
OMN-1 Section 3.1 allows the use of testing that was conducted prior to the implementation of OMN-1 if it meets the requirements of the Code Case. LaSalle County Station intends to utilize the testing performed under GL 89-10 to satisfy the requirement for a one-time test to verify the capacity of each MOV to meet its safety-related design basis requirements.
- 2.
OMN-1 Section 3.2 requires that each MOV be tested during the preservice test period or before implementing inservice inspection.
LaSalle County Station intends to utilize the testing performed under GL 89-10 to satisfy this requirement. LaSalle County Station will perform a new preservice test when an MOV undergoes maintenance or modification that could affect its performance.
- 3.
OMN-1 Section 3.3(b) states that maintenance activities, such as stem lubrication, shall not be conducted if they might invalidate the as-found condition for inservice testing. At LaSalle County Station the frequency of stem lubrication and periodic MOV verification testing differ considerably, and the times at which these activities are optimally performed often do not coincide. As part of our GL 96-05 program, as-found data has been collected for a sample population of MOVs under various lubrication conditions. The results from this as-found data was used to create stem factor variability assumptions that are used to estimate the effect of stem lubrication on stem performance over the entire lubrication cycle.
As described above, Relief has been requested from OMN-1, Section 3.3(b) as it applies to inservice testing being conducted in the as-found condition.
With this Relief, if testing were to occur directly following maintenance activities such as a stem lube, test results would not be invalidated as methods used to analyze the test results take into consideration testing under these circumstances.
Therefore the intent of OMN-1, Section 3.3(b), that testing is performed under conditions that will not hinder the ability to determine applicable functional margins and determine operational readiness, is maintained utilizing the methods previously described.
- 4.
OMN-1 Section 3.3(c) requires the inservice test program to include a mix of static and dynamic MOV performance testing. LaSalle County Station will utilize the JOG program's mix of static and dynamic MOV performance testing to satisfy this requirement.
Additionally, LaSalle County Station will utilize the existing engineering standards, which are consistent with the JOG standards, to conduct evaluations to alter the mix of required MOV performance testing, when applicable, in order to meet this requirement.
- 5.
OMN-1 Section 3.3.1(b) requires MOV inservice testing to be conducted every two refueling cycles or three years (whichever is longer), if insufficient data exists
Attachment Valve Relief Request - RV-02 Utilization of ASME Code Case OMN-1 (Revision 0)
(Page 5 of 5) to determine inservice test frequencies.
LaSalle County Station has sufficient MOV testing data to justify its current testing frequencies, and therefore meets this requirement.
- 6.
OMN-1 Section 6.4.4 requires calculations for determining MOV functional margin to be evaluated to account for anticipated time related changes in performance. LaSalle County Station will utilize the JOG process for setting test frequencies that is based on margin and safety significance to meet this requirement.
- 7.
According to Table 2 of Regulatory Guide 1.192, the only testing that is described within ISTC that will need to continue to be performed with the adoption of OMN-1 is that of leakage testing as described by ISTC-3600.
Therefore Position Indication Testing (PIT) as described by ISTC-3700 need not be specifically identified or performed per the requirements of ISTC. LaSalle County Station will however continue to perform position indication testing at a frequency consistent with JOG guidelines during MOV diagnostic testing.
- 8.
A comparison of GL 96-05 program to the IST program has identified a number of LaSalle County Station MOVs that have IST requirements but are not subject to diagnostic testing. LaSalle County Station will continue to stroke time test and position indication test these identified MOVs in accordance with ISTC requirements.
6. Duration of Proposed Alternative
This proposed alternative will be utilized for the entire third 120-month interval.
7. Precedents
This relief request was previously approved for the second ten-year interval at LaSalle County Station Units 1 and 2 as Relief Request RV-14, documented in Safety Evaluation and Letter dated November 21, 2002.