ML20196J493
| ML20196J493 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 12/07/1998 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML20196J481 | List: |
| References | |
| NUDOCS 9812100098 | |
| Download: ML20196J493 (12) | |
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1 Uh p *, UNITED STATES e S U NUCLEAR REGULATORY COMMISSION f WASHINGTON D.C. 20es&4001 ca,]E SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE THIRD 10-YEAR INSERVICE TESTING PROGRAM SOUTHERN NUCLEAR OPERATING COMPANY. INC.
EDWIN 1. HATCH NUCLEAR PLANT UNITS 1 AND 2 DOCKET NOS. 50-321 AND 50-366 1
1.0 INTRODUCTION
l Title 10 of the Code of Federal Reoulations (10 CFR), Section 50.55a, requires that inservice testing (IST) of certain American Society of Mechanical Engineers (ASME) Code Class 1,2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and J Pressure Vessel Code (ASME Code) and applicable addenda, except where alternatives have i been authorized, or relief has been requested by Southern Nuclear Operating Company, Inc.
(SNC/ licensee) for the Edwin 1. Hatch Nuclear Plant, Units 1 and 2 (Hatch), and granted by the Commission, pursuant to Sections (a)(3)(i), (a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a. In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; l or (3) conformance is impractical for its facility. Section 50.55a authorizes the Commission to l approve attematives and to grant relief from ASME Code requirements upon making the necessary findings. NRC guidance contained in Generic Letter (GL) 89-04, " Guidance on Developing Acceptable Inservice Testing Programs," provides alternatives to the Code requirements determined acceptable to the staff. Attematives that conform with the guidance in GL 89-04 may be implemented without additional NRC approval, but are subject to review ;
during inspect;ons. Further guidance was given in GL 89-04, Supplement 1, and NUREG-1482, l
" Guidelines for Inservice Testing at Nuclear Power Plants."
The Hatch Units' 1 and 2 third 10-year interval IST program for pumps and valves was submitted in a letter dated September 15,1995. The third 10-year interval for Unit 1 started on January 1,1996, and will end on December 31,2006. In accordance with the proposed alternative of Relief Request RR-G-2, the third 10-year interval for both Units 1 and 2 began on January 1,1996. In addition, in accordance with the proposed alternative of Relief Request RR-G-1, which was approved in a letter dated August 29,1995, the applicable Codes used in the Hatch IST program will be the ASME Operation and Maintenance (OM) Code-1990 for pumps and valves, with the exception of relief valves. The applicable Code for relief valves will be ASME OM Code-1995.
In a letter dated March 11,1998, the licensee submitted four new relief requests and one revised relief request for its IST program. The staff's evaluation of the proposed relief requests are discussed herein.
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2.0 PUMP RELIEF REQUEST 2.1 Relief Request RR-P-15 .
SNC has requested relief from the Code instrument full-scale range and instrument accuracy requirements of OM Code-1990, Paragraph ISTB 4.6.1(b)(1) and Table ISTB 4.6.1-1, respectively, for the standby diesel service water (SDSW) vertical line shaft pump 2P41-C002.
The licensee proposes to use the installed instrumentation.
2.1.1 Licensee's Basis for Requesting Relief The licensee states:
The flowrate for the SDSW pump is determined by measuring the differential pressure (dp), in inches of water, across a flow element and then using the vendor correlation chart to convert dp to flowrate in gallons-per-minute (gpm). The dp indicator (2P41-R383) has a full-scale range of -178 inches of water to +178 inches of water, which is greater than three times the reference value, and is calibrated to i 4 inches of water (i.e.,* 1.125% of full-scale). The indicator has a range which allows measurement of the flowrate in either direction across the flow element, thus the negative and positive scale ranges. The vendor supplied dp to flow correlation chart has a range of 50 - 145 inches of water which corresponds to a flowrate range of 500 - 850 gpm.
The reference dp for this pump is presently 82 inches of water which corresponds to a flow rate of 640 gpm. The OM Code would allow a full-scale range of 0 - 246 inches of water (i.e.,3 X 82) and a calibration accuracy of i 4.92 inches of water (i.e., 0.02 X 246).
The combined range and accuracy of the installed instruments is within the maximum allowable of ISTB 4.6.1(1) and Table 4.6.1-1. The maximum Code allowable dp variance would be i 4.92 inches of water whereas the actual dp variance is i 4 inches of water. Therefore, use of the existing dp indicators and the vendor correlation chart provides flowrate measurements for IST that are at least as accurate as required by the OM Code.
2.1.2 Altemate Testing The licensee proposes:
None, the installed instrumentation will be utilized to determine flowrate for the SDSW pump. The use of this instrumentation is supported by the guidance contained in NRC NUREG-1482, Section 5.5.1, since the combined range and accuracy variance of the installed instrumentation is within the maximum allowable variance of the OM Code. This relief request was developed for documentation purposes as described in NUREG-1482.
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2.1.3 Evaluation !'
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l The Code requires that analog instruments shall not exceed a full-scale range of 3 times the ;
reference value. The SDSW pumps have a flow gauge that reads in inches of water. This '
gauge allows flow rates to be measured in both directions. The full-scale range of this gauge ,
is 4.34 times the reference value. Applying the Code-allowed accuracy of12 percent of the l full-scale range to the reference value of 82 inches of water, the absolute variance in the value is *4.92 inches of water. l l The licensee has proposed to use the installed instrumentation, which has an accuracy of l 14 inches of water. Since accuracy of the instrumentation is better than the absolute accuracy required by the Code, the proposed alternative provides an acceptable level of quality and l- safety.
2.1.4 Conclusion The proposed alternative to the Code instrument full-scale range and instrument requirements of OM Code-1990, Paragraph ISTB 4.6.1(b)(1) and Table ISTB 4.6.1-1, respectively, for the SDSW vertical line shaft pump 2P41-C002 is authorized pursuant to 10 CFR 50.55a(a)(3)(i) based on the attemative providing an acceptable level of quality and safety.
3.0 VALVE RELIEF REQUESTS 3.1 Relief Request RR-V-7 The licensee has proposed to deviate from the guidance provided in GL 89-04, Position 2, for the high pressure coolant injection (HPCI) suction check valves 1E41-F045 and 2E41-F045 i from the suppression pool. The licensee has proposed not to perform partial-stroke exercising l with flow after valve reassembly or during cold shutdown.
3.1.1 Licensee's Basis for Requesting Relief The licensee states:
This normally closed check valve is located on the HPCl pump suction line from the suppression pool. The valve does not experience flow during any normal mode ,
of reactor operation or shutdown conditions or during HPCI pump surveillance testing. The HPCI pump is normally aligned to the condensate storage tank (CST) for injection to the reactor coolant system. The pump suction transfers to the i suppression pool upon indication of a low water level in the CST which would only occur during an extended HPCI injection because 100,000 gallons of water are i- always maintained in the CST for ECCS [ emergency core cooling system] usage.
! Periodic pump surveillance testing is performed by recirculating water from/to the j CST.
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I l i The valve remains in the closed position in a torus water environment and does <
not experience any flow which could cause wear of internal components. Previous !
] valve inspections in conjunction with disassembly have shown very little, if any, !
j degradation other than the expected minor corrosion and the valve was capable of
- i full stroke exercising each time. '
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Exercising this check valve with flow would require aligning the HPCI pump suction to the suppression pool and discharging to the CST. Pumping suppression pool water to CST would significantly degrade the water quality in the CST making it unusable for other plant requirements.
GL 89-04, Position 2, [provides] that, if practical, a partial exercise with flow be performed for check valves that are disassembled after reassembly. There is no possible flow path available for partial exercising this check valve that would not introduce suppression pool water into the HPCI system piping or back to the CST.
This is a simple swing disc check valve...which does not require removal of the valve intemals to perform a manual stroke test or visual inspection. Even if exercising [and] inspection resulted in valve repairs, the valve could still be manually stroked after the intemals were reinstalled in the valve. 1 i
3.1.2 Altemate Testing !
The licensee proposes:
Each valve will be disassembled, manually full stroke exercised and visually inspected to confirm its operational readiness during its respective unit's refueling outage in accordance with ISTC 4.5.4(c). This valve disassembly will confirm that the valve is capable of full stroking and that its intemals are structurally sound (no loose or excessively corroded parts).
Since exercising is impractical nfter reassembly, the plant procedure utilized for valve disassembly requires: personnel performing the inspection, and overseeing the work to be familiar with the valve's operation; personnel to utilize the vendor 3
manual for disassembly and reassembly; personnel to ensure that the stop area l on the valve body, bonnet, or disc exhibit no deformation; manually exercising the disc to confirm free movement through the entire range of travel, including full open and close; inspection of the disc and body seating surface for evidence of cracking, tearing, deformation or missing surfaces; inspection of the intemal surfaces, body and disc, to ensure no erosion, cracking, or excessive corrosion exists; inspection to ensure that the valve exhibits no damage or missing components, no excessive play, wom or bent hinges, pins, hangers, or other components; and independent verification of the As-Left condition to ensure that no tools, cleaning materials, or other inappropriate materials are left in the valve prior to installation of the bonnet cover.
Therefore, the disassembly procedure includes adequate quality controls to ensure the operational readiness and full stroke capability of the valve after reassembly.
3.1.3 Evaluation The Code allows check valves to be disassembled and inspected as an alternative to flow testing to verify operability and thereby meet the Code exercise requirements. GL 89-04, Position 2, states the following: "The NRC staff position is that valve disassembly and inspection can be used as a positive means of determining that a valve's disk will full-stroke 4
exercise open or of verifying closure capability, as permitted by IVN-3522 [ISTC 4.5.2]. If l j
possible, partial valve stroking quarterly or during cold shutdowns, or after reassembly must be performed." The licensee states that no flow path exists to partial exercise this check valve without suppression pool water contaminating the HPCI system piping or the condensate storage tank. The licensee implies that it is possible to partial-stroke exercise these check i
valves with flow after reassembly but the consequences of that action would be a clean-up of the referenced systems to achieve the necessary quality. Therefore, strict adherence to the i
guidance would be a hardship without a compensating increase in safety.
1 l The licensee has proposed not to perform any partial-stroke testing of the HPCI suction check valves. The licensee states that it has specific procedures in place to ensure that check valves, which are disassembled to comply with the Code exercise method requirements, are installed correctly after reassembly. Therefore, the proposed testing provides a reasonable assurance of operational readiness.
3.1.4 Conclusion j The proposed attemative to the guidance provided in GL 89-04, Position 2, of not performing '
partial-stroke testing during cold shutdowns or after reassembly for the HPCI suction check valves is authorized pursuant to 10 CFR 50.55a(a)(3)(ii) based on the determination that compliance with the specific guidance results in a hardship without a compensating increase in the level of quality and safety.
3.2 Relief Request RR-V-12 The licensee has requested relief frorn the Code check valve disassembly and inspection frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), for residual heat removal (RHR) valves 1E11-F126A8B (Unit 1) and 2E11-F124A&B (Unit 2), and core spray valves 1E21 -F040A&B (Unit 1) and 2E21-F040A&B (Unit 2), associated with the keep-fill system. The licensee has proposed to use the guidance provided in GL 89-04, Position 2, with the exception that certain valves in the group will not be of identical size and are in different systems.
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I i 3.2.1 Licensee's Basis for Requesting Relief '
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l The licensee states:
These valves close to maintain the RHR and Core Spray System piping filled with water during normal plant operation should the non-safety related jockey pumps be unavailable. Exercising requires isolating the associated jockey pump and
- confirming check valve closure by monitoring the RHR and Core Spray system level switch alarms, or performing some type of pressure decay test. Other valve '
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leakage within the system boundary could make it difficult to confirm actual check valve closure.
At least one jockey pump is maintained inservice during normal operation and the
.. other(s) are in stand-by. Isolating and swapping pumps to confirm check valve
- closure imposes additional hardships on operations personnel and undue -
- challenges on system components for the minimal safety benefit derived.
1 Disassembly of each check valve requires an excessive number of man-hours I when compared to the safety-benefit derived. The RHR system is usually either i on or near critical path during refueling outage due to requirements to support fuel j movement and core reload in the shutdown cooling mode of operation. The Core Spray System is also relied upon as a reactor coolant system make-up supply for
! a significant period of time during outages. Therefore, disassembly of all four j check valves has a significant potential to impact the RHR and Core Spray ,
- systems out-of-service time and therefore [could delay] other related outage ;
i activities.
} The valves on each unit are of the same manufacturer, model, and orientation.
However, they vary minimally in size. The RHR (E11) valves are 2" diameter and the Core Spray (E21) valves are 1.5" diameter. Even though the valves vary in i
] size, all are subjected to the same environmental and system operating conditions. !
j NRC Genetic Letter 89-04, Position 2, recognized that a sampling plan adequately J monitors for any degradation and is sufficient to maintain operational readiness, j and thus provides an adequate level of safety for such valves.
3.2.2 Alternate Testing The licensee proposes:
The guidance of NRC Generic Letter 89-04, Position 2, with an exception for the 0.5" difference in valve size, will be utilized to implement a sample disassembly and inspection program for these valves (i.e.,4 valves / group). One valve from each unit will be disassembled, inspected, and full-stroke exercised during the respective units refueling outage. A different valve will be selected each outage. If ,
the valve cannot be full-stroke exercised, or there is evidence of degradation that would affect its operational readiness, then the remaining valves on that unit will be disassembled during the same outage.
l 3.2.3 Evaluation !
l The Code allows check valves to be disassembled and inspected as an attemative to flow testing to verify operability and, thereby, meet the Code exercise requirements. The Code !
requires that each check valve that enacts this provision be disassembled every refueling j outage. GL 89-04, Position 2, states that where the licensee determines that it is burdensome I to disassemble and inspect all applicable valves each refueling outage, a sample disassembly and inspection plan for groups of identical valves in similar applications may be employed.
Disassembly of all the keep-fill check valves in the proposed group would unnecessarily impact outage schedules and would be a hardship.
, The licensee has proposed to adopt the guidance in Position 2 with the exception that valves in the group are of different sizes and are in different systems. Position 2 provides guidance to establish a sampling plan that requires that each valve in the group be the same design (manufacturer, size, model number, and materials of construction) and have the same service conditions including valve orientation. Previously, the staff has considered valves of different sizes to be grounds for not being in conformance with the guidance of Position 2. This is clearly the case for valves of large differences in size (as an example, a 20-inch valve and a 2-inch ,
valve) but the guidance may allow for valves of slightly different sizes to be grouped together.
The size difference of one-half inch does not appear to present a significant deviation from the guidance in Position 2. Valves that are in different systems do not typically see the same service conditions. However, the licensee has not provided detailed justification as to why the di4erences in valve size and system conditions do not preclude the valves from being placed in the same group.
Long-term authorization cannot be provided for the licensee's proposed attemative. An interim l period of 1 year or until the next refueling outage, whichever is shorter. is authorized to allow the licensee to develop the information to justify valves of different sizes and of different l systems to be placed in the same group. This information may include, but not be limited to, generic- and plant-specific test data, system operational data, design and maintenance information, and generic- and plant-specific failure information. The burden falls with the licensee to demonstrate that valves cf different sizes, which reside in different systems, should be included in the same disassembly and inspection group. The proposed attemative provides
- reasonable assurance of operational readiness for the interim period because the length of the interim period does not extend beyond the next refueling outage and these valves are only disassembled and inspected during refueling outages.
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The staff has recently approved an attemate method for testing check valves at the Wolf Creek Generating Station in a Safety Evaluation (SE) dated November 26,1997. In the SE, the staff allows the use of Appendix II, Check Valve Condition Monitoring Program, included in ASME OM Code-1996 Addenda to the ASME OM Code-1995 Edition. Appendix ll was authorized for use with a number of conditions and limitations including: (1) where the most frequently performed appropriate measure (test, examination, or preventive maintenance) extends beyond 60 months, performance, examination, maintenance history, and test experience from previous tests shall be evaluated to justify the periodic verification interval; (2) the test or examination interval shall not exceed 120 months; (3) risk insights from other activities may be used when reviewed and approved by the staff to ensure that the testing, examination, or preventive
meascres taken are commensurate with each valve's safety significance; (4) check valve obturator movement will be tested or examined in both the open and closed direction to ensure unambiguous detection of functionality degraded check valves; (5) extensions of IST intervals will consider plant safety impact and be supported and justified by applicable methods of t trending to provide assurance that the valve is capable of performing its intended function over the entire interval; (6) initial IST interval extensions of any valve must be limited to two fuel cycles or 3 years, and subsequent extended intervals must be limited to one fuel cycle per extension, up to 10 years; and (7) if the Condition Monitoring Program is discontinued, the testing and examination will revert back to the original ASME Code requirements. The staff considers that check valve issues can be addressed by adoption of a check valve condition monitoring program as provided in Appendix ll of the 1995 ASME OM Code. The licensee should consider this approach in evaluating its Code check valve testing program at the site.
3.2.4 Conclusion l
The proposed alternative to the Code check valve disassmebly and inspection frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), for RHR valves 1E11-F126A&B (Unit 1) and 2E11-F124A&B (Unit 2), and core spray valves 1E21-F040A&B (Unit 1) and 2E21-F040A&B (Unit 2), associated with the keep-fill system, is authorized on an interim basis pursuant to 10 CFR 50.55a(a)(3)(ii), based on the determination that compliance with the specified requirements results in a hardship without a compensating increase in the level of quality and safety. The length of the interim period is 1 year or until the next refueling outage, whichever is shorter During the interim period, the licensee should develop detailed '
justification as to why these valves should be included in the same disassemble and inspection group. Alternatively, the licensee should consider use of Appendix 11 of the 1995 OM Code for i condition monitoring of check valves.
3.3 Relief Request RR-V-14 The licensee has requested relief from the Code check valve disassmebly and inspection frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), for the plant service water (PSW) supply to the main control room (MCR) air conditioning unit check valves 1P41F1074 and 1P41-F1075. The licensee has proposed to use the guidance in GL 89-04, Position 2.
3.3.1 Licensee's Basis for Requesting Relief The licensee states:
These valves open to provide Unit 1 PSW [ plant service water] supply to the Unit 1 MCR (main control room) air conditioning units and close if supply should be transferred to the Unit 2 PSW system. The supply lines are not provided with flow measuring instrumentation therefore, exercising with flow is impractical.
Additionally, there are no instruments upstream of the valves that can be utilized to confirm valve closure.
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The disassembly of each check valve requires an excessive number of man-hours when compared to the safety-benefit derived. The MCR air conditioning units are required during all modes of normal operation and the majority of the time during refueling outages to satisfy requirements for inhabitability. Disassembly of both check valves each outage has a significant potential to impact the system out-of-service time and delay other related outage activities.
The valves are of the same size, manufacturer, model, and orientation and are subjected to the same environmental and system operating conditions. NRC Generic Letter 89-04, Position 2, recognized that a sampling plan adequately monitors for any degradation and is sufficient to maintain operational readiness, and thus provides an adequate level of safety for such valves.
3.3.2 Attemate Testing The licensee proposes:
The guidance of NRC Generic Letter 89-04, Position 2, will be utilized to implement a sample disassembly and inspection program for these valves (i.e.,2 valves / group). One valve will be disassembled, inspected, and full-stroke exercised each refueling outage. A different valve will be selected each outage. If the valve cannot be full-stroke exercised, or there is evidence of degradation that
, would affect its operational readiness, then the remaining valve will be disassembled during the same outage. The valve will be partial exercised with flow after reassembly in conjunction with retuming the associated MCR air conditioning unit to service.
3.3.3 Evaluation The Code allows check valves to be disassembled and inspected as an attemative to flow testing to verify operability and, thereby, meet the Code exercise requirements. The Code requires that each check valve, which enacts this provision, be disassembled every refueling outage. GL 89-04, Position 2, states that if the licensee detemlines that it is burdensome to disassemble and inspect all applicable valves each refueling outage, a sample disassembly and inspection plan for groups ofidentical valves in similar applications may be employed.
Position 2 provides guidance to establish a sampling plan that requires that each valve in the group be the same design (manufacturer, size, model number, and materials of construction) and have the same service conditions including valve orientation.
The licensee has stated that the Code testing is a hardship because the disassembly of each check valve every refueling outage requires an excessive number of man-hours when compared to the safety benefit derived. In addition, the licensee stated that disassembly of both check valves each outage has a significant potential to impact the system out-of service time and delay other related outage activities. It would be a hardship without a compensating increase in the level of quality and safety for the licensee to meet the Code requiremen's since the attemative provides an acceptable means to assess the operational readiness of these valves.
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The licensee has proposed to adopt the guidance in Position 2 without any exceptions. This testing provides a reasonable assurance of operational readiness because the licensee has adopted guidance provided by the staff in GL 89-04, Position 2.
3.3.4 Conclusion The proposed attemative to the Code check valve cisassembly and inspection frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), for the PSW supply to the MCR air conditioning unit check valves 1P41-F1074 and 1P41-F1075, is authorized pursuant to l
10 CFR 50.55a(a)(3)(ii) based on the determination that cornpliance with the specified l requirements results in a hardship without a compensating increase in the level of quality and j safety.
l 3.4 Relief Request RR-V-15 l The licensee has requested relief from the Code check valve disassembly and inspection frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), PSW supply to the MCR air conditioning and the essential low pressure coolant injection (LPCI) inverter room cooler unit check valves 2P41-F098 and 2P41-F105. The licensee has proposed to use the guidance in GL 89-04, Position 2, with the exception that certain valves in the goup will not be of identical size.
3.4.1 Licensee's Basis for Requesting Relief The licensee states:
These valves open for Unit 2 PSW supply to the MCR air conditioners and LPCI inverter Room Coolers and close when supply is provided from Unit 1. The supply lines are not provided with flow measuring instrumentation therefore, exercising with flow is impractical. Additionally, there are no instruments upstream of the valves that can be utilized to confirm valve closure. l The disassembly of each check valve requires an excessive number of man-hours when compared to the safety-benefit derived. The MCR air conditioning units are required during all modes of normal operation and the majority of the time during refueling outages to satisfy requirements for inhabitability. Disassembly of both check valves each outage has a significant potential to impact the system out-of-service time and delay other related outage activities.
The valves are of the same manufacturer, model, and orientation. However, they are minimally different in size. The F098 valve is 4" diameter and the F105 valve is 3"in diameter. Even though the valves vary minimally in size, they are subjected to the same environmental and system operating conditions. NRC Generic Letter 89-04, Position 2, recognized that a sampling plan adequately monitors for any degradation and is sufficient to maintain operational readiness, and thus provides an adequate level of safety for such valves.
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3.4.2 Attemate Testing The licensee proposes:
The guidance of NRC Generic Letter 89-04, Position 2, with an exception for the 1" difference in valve size, will be utilized to implement a sample disassembly and inspection program for these valves (i.e. 2 valves / group). One valve will be disassembled, inspected, and full-stroke exercised during each refueling outage.
A different valve will be selected each outage. If the valve cannot be full-stroke exercised, or there is evidence of degradation that would affect its operational readiness, then the remaining valve will be disassembled during the same outage.
The valve will be partial [ly] exercised with flow after reassembly in conjunction with retuming the associated MCR air conditioning unit to service. l 3.4.3 Evaluation The Code allows check valves to be disassembled and inspected as an attemative to flow testing to verify operability and, thereby, meet the Code exercise requirements. The Code requires that each check valve, which enacts this provision, be disassembled every refueling outage. GL 89-04, Position 2, states that if the licensee determines that it is burdensome to disassemble and inspect all applicable valves each refueling outage, a sample disassembly and inspection plan for groups ofidentical valves in similar applications may be employed.
Disassembly of these check valves cannot be performed at any other time than refueling outages and may unnecessarily impact outage schedules and would therefore be a hardship.
The licensee has proposed to adopt the guidance in Position 2 with the exception that valves in the group are of different sizes. Position 2 provides guidance to establish a sampling plan that requires that each valve in the group be the same design (manufacturer, size, model number, and materials of construction) and have the same service conditions including valve orientation.
Previously, the staff has considered valves of different sizes to be grounds for not being in conformance with the guidance of Position 2. This is clearly the case for valves of large differences in size (as an example, a 20-inch valve and a 2-inch valve) but the guidance may allow for valves of slightly different sizes to be grouped together. The size difference of 1 inch does not appear to present a significant deviation from the guidance in Position 2. However, the licensee has not provided detailed justification as to why the difference in valve size does not preclude the valves from being placed in the same group.
Long-term authorization cannot be provided for the licensee's proposed alternative. An interim period of 1 year or until the next refueling outage, whichever is shorter. is authorized to allow the licensee to develop the information to justify valves of different sizes to be placed in the same group. This information may include, but not be limited to, generic- and plant-specific test data, design and maintenance information, and generic- and plant-specific failure information.
The burden falls with the licensee to demonstrate that valves of different sizes should be included in the same disassembly and inspection group. The proposed attemative provides reasonable assurance of operational readiness for the interim period because the length of the
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l interim period does not extend beyond the next refueling outage and these valves are only I disassembled and inspected during refueling outages.
The staff has recently approved an attemate method for testing check valves at the Wolf Creek Generating Station in an SE dated November 26,1997. The licensee should review this SE for possible application to the Hatch plant as discussed in Section 3.2.3 of this SE.
3.4.4 Conclusion The proposed attemative to the Code check valve disassembly and inspectirn frequency requirements of the OM Code-1990, Paragraph ISTC 4.5.4(c), for the PSW supply to the MCR air conditioning and the essential LPCI inverter room cooler unit check valves 2P41-F098 and 2P41-F105, is authorized on an interim basis pursuant to 10 CFR 50.55a(a)(3)(ii), based on the
' determination that compliance with the specified requirements results in a hardship without a compensating increase in the level of quality and safety. The length of the interim period is 1 year or the next refueling outage, whichever is shorter During the interim period, the licensee should develop detailed justification as to why these valves should be included in the same disassembly and inspection group.
4.0 CONCLUSION
The staff concludes that the relief requests as evaluated and modified by this SE will not compromise the reasonable assurance of operational readiness of the pumps and valves in question to perform their safety-related functions. Proposed alternatives in Relief Requests RR-V-12 and RR-V-15 were approved on an interim basis for a period of 1 year or until the next refueling outage, whichever is shorter, to allow the licensee to develop detailed justification as to why the check valves referenced in the relief requests should be included in the same disassembly and inspection group. The alternative proposed in Relief Request RR-P-15 is authorized pursuant to 10 CFR 50.55a(a)(3)(i) in that it provides an acceptable level of quality and safety. Relief Requests RR-V-7, RR-V-12, RR-V-14, and RR-V-15 are authorized pursuant ,
to 10 CFR 50.55a(a)(3)(ii)in that it has been determined that compliance with the specific l
requirements results in a hardship without a compensating increase in the level of quality and safety.
Principal Contributor: Joseph Colaccino Date: December 7, 1998 l
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