ML20070M853
| ML20070M853 | |
| Person / Time | |
|---|---|
| Site: | Fort Calhoun  |
| Issue date: | 03/31/1994 |
| From: | Ransom C EG&G IDAHO, INC. |
| To: | Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20070B993 | List: |
| References | |
| CON-FIN-L-2594 EGG-RTAP-11220, TAC-M84936, NUDOCS 9405030325 | |
| Download: ML20070M853 (44) | |
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EGG-RTAP-11220 5
TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM FORT CALHOUN STATION UNIT 1 Docket Number 50-285 i
3 C. B. Ransom Published March 1994
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Idaho National Engineering Laboratory EG&G Idaho, Inc.
. s Prepared for the U.S. Nuclear Regulatory Commission
' Washington, D. C. 20555 .
Under DOE Contract Number DE-AC07-76IDO1570 FIN Number L2594, Task Order Number 7 TAC Number M84936 h5olO 3'A M
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ABSTRACT l This report presents the results of our evaluation of the Fort Calhoun Station, Unit 1,
- Inservice Testing program for safety-related pumps and valves.
PREFACE :
This report is part of the " Technical Assistance in Support of Operating Reactors Inservice Testing Relief Requests" program conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation, Mechanical Engineering Branch, by EG&G Idaho, Inc., DOE /NRC Support Programs.
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c FIN No. L2594 '
l'&R No. 920-19-05-02-0 Docket No. 50-285 TAC No. M84936 ii
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CONTENTS - 1 i
i ABSTRACT .............................. . ii i PREFACE ................................. il
- 1. INTRODUCTION ........................... 1 ,
1.1 IST Program Description . . . . . . . . . . . . . . . . . . . . . . 'l 1.2 ~ IST Requirements . . . . . . . . . . . . . . . . . . . . . . . . . 1. j 1.3 Scope and Limits of the Review . . . . . . . . . . . . . . . . . . . 2
- 2. PUMP TESTING PROGRAM ...................... 3 2.1 General Pump Request . . . . . . . ................ 3 2.1.1 Inlet and Differential Pressure Determination .......... 3 2.2 Charging Pumps ......................... 4 2.2.1 Pump Flow Rate Acceptance Criteria ............. 4
- 3. VALVE TESTING PROGRAM . . . . . . . . . . . . . . . . . . . . . . 7 3.1 Various Systems ......................... 7 i
3.1.1 Thermal Relief Valves ................... 7 t 3.1.2 Imk Test Containment Isolation Valves (CIVs) ......... 8 3.2 Safety Injection Systems . . . . . . . . . . . . . . . . . . . . . . 9 3.2.1 Category A/C Valves . . . . . . . . . . . . . . . . . . . . 9 3.2.2 Category C Valves . . . . . . . . . . . . . . . . . . . . . 12 3.3 Containment Spray System . . . . . . . . . . . . . . . . . . . . 14 ,
1 3.3.1 Category C Valves . . . . . .. . . . . . . . . . . . . . . . 14 i 3.4 Auxiliary Feedwater System .................... 17 .
L 3.4.1 Category C Valves . . . . . . . . . . . . . . . . . . . . . 17 l f'
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- 4. DEFERRED TEST EVALUATIONS . . . . . . . . . . . . . . . . . . . . 19 4.1 Bases for Deferring Valve Exercising .. . . . . . . . . . . . . . . . . 19 4.2 Conclusion ............. ,,.....,,.,,, 19 4.3 Disassembly and Inspection . . . . . . . . . . . . . . . . . . . . 20 j t
APPENDIX A -IST PROGRAM ANOMALIES . . . . . . . . . . . . . . . . A-1 TABLES I
4.1 Deferred Test Evaluations Fort Calhoun Station . . . . . . . . . . . . . . . 21 i
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9 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM FORT CALHOUN STATION UNIT 1
- 1. INTRODUCTION This report provides the results of the technical evaluation of certain relief requests from the pump and valve inservice testing (IST) program for the Fort Calhoun Station, Unit 1, submitted by Omaha Public Power District.
Section 2 presents Omaha Public Power District's bases for requesting relief from the requirements for pumps followed by an evaluation and conclusion. Section 3 presents similar information for valves. Section 4 presents a summary of the evaluations of deferred test justifications that involve the frequency of testing safety-related valves.
Appendix A lists program inconsistencies and omissions, and identifies needed program changes.
1.1 IST Program Description Omaha Public Power District (OPPD) submitted their Third 120 month Inspection Interval IST program with a letter to the Nuclear Regulatory Commission (NRC) dated November 13, 1992. The IST program covers the third ten-year interval starting September 26,1993, and ending September 25,2003. The relief requests pertain to requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (the Code),Section XI,1989 Edition and the Code of Federal Regulations (CFR),
10 CFR 50.55a. This Edition of the Code prescribes that the pump and valve testing be performed in accordance with the requirements of the ASME/American National Standards Institute (ANSI) Operations and Maintenance (O&M) Standards Parts 6 and 10, respectively.
1.2 IST Requirements 10 CFR 50.55a(f) states that IST of certain ASME Code Class 1,2, and 3 pumps and valves will be done according to the ASME Code,Section XI, Subsections IWP and IWV, except where the alternative is authorized or relief is granted by NRC in accordance with 10 CFR 50.55a(a)(3)(i), (a)(3)(ii), or (f)(6)(i). OPPD requests relief from the ASME Code testing requirements for specific pumps and valves. Certain of these requests are evaluated in this Technical Evaluation Report (TER) using the acceptance criteria of the Standard Review Plan, Section 3.9.6, NRC Generic Letter No. 89-04 (GL 89-04), " Guidance on Developing Acceptable Inservice Testing Programs," and 10 CFR 50.55a. Other requests in the licensee's IST program that are not evaluated in this TER, may be granted by provisions of GL 89-04 or include non-Code Class 1,2, or 3 components.
In rulemaking to 10 CFR 50.55a effective September 8,1992 (See 57 Federal Recister 34666), the 1989 Edition of ASME Section XI was incorporated in 10 CFR 50.55a(b). The 1989 Edition of Section XI provides that the rules for IST of pumps and valves are as specified in ASME/ ANSI O&M Part 6 (OM-6), Inservice Testing of Pwnps in Light-Water 1
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Reactor Power Plants, and Part 10 (OM-10), inservice Testing of Valves in Light-Water Reactor Power Plants.
1.3 Scope and Limits of the Review The scope of this review includes, but is not limited to, the cold shutdown justifications, refueling outage justifications, and relief requests for safety-related Code Class 1,2, and 3 pumps and valves submitted with the licensee's IST program. Other portions of the program, such as general discussions, pump and valve test tables, etc., are not necessarily reviewed. Endorsement of these aspects of the program by the reviewer is not stated or implied.
The Containment Spray, Chemical and Volume Control, Steam Generator Feedwater, and Safety Injection Systems were specifically reviewed for scope and completeness of the licensee's IST program. The system drawings were reviewed and many valves evaluated to determine if they perform a safety-related function. Although this review was more detailed than normally performed, it was a spot check and does not constitute a comprehensive system review or endorsement of the licensee's scope. The spot check of the IST program plan and the piping and instrumentation drawings (P& ids) for these systems did not reveal any omissions or other problems with the IST program.
The evaluations in this TER are applicable only to the components or groups of components identified by the submitted requests. Further, the evaluations and recommendations are limited to the requirement (s) and/or function (s) explicitly discussed in the applicable TER section. For example, the results of an evaluation of a request involving testing of the containment isolation function of a valve cannot be extended to allow the test to satisfy a requirement to verify the valve's pressure isolation function, unless that extension is explicitly stated.
OPPD provided several deferred test justifications for exercising Category A, B, and C valves during cold shutdowns and refueling outages instead of quarterly. Valves identified to be tested during cold shutdowns need not be tested if testing was performed within three months of the cold shutdown in accordance with IWV-3412(a) and -3522. These justifications were reviewed and appear to be acceptable except as noted in Section 4 of this report and in Appendix A.
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- 2. PUMP TESTING PROGRAM The following relief requests are evaluated against the requirements of ASME/ ANSI OMa-1988, Part 6; 10 CFR 50.55a; and applicable NRC positions and guidelines. A summary is presented for each relief request followed by the licensee's basis for relief and the evaluation with the reviewer's recommendations. The requests are grouped according to :
topic or system.
2.1 General Pumo Request 2.1.1 1016 and Differential Pressure Determination 2.1.1.1 Relief Request. Pump Relief Request El requests relief from the direct measurement of differential pressure requirement of OM-6, Subsection 4.6.2.2, for the raw water, low pressure safety injection (LPSI), high pressure safety injection (HPSI),
containment spray (CS), and boric acid pumps, which do not have installed inlet pressure instruments. The licensee proposes to determine pump inlet pressure and differential pressure by calculating the pressure due to the head of water above the pump inlet.
2.1.1.1.1 Licensee's Basis for Reanstine Relief--The following text is quoted from pump relief request El in the Fort Calhoun Station Third Inspection Interval IST Program dated November 13,1992:
System design does not include instrumentation for direct measurement of inlet and differential pressure.
Alfernate Testing: The raw water pump inlet pressure will be calculated based oa the riv:r level and the elevation of the pump suction bells. The pump differential pressure !
will then be calculated based on the measured discharge pressure and the calculated i inlet pressure. Since (1) the river provides the required positive preuure at the suction of the pumps, (2) the river level does not change when a pump is started, and (3) at least one pump is usually in service, the calculated inlet pressure prior to starting a pump is the same as with a pump running.
The LPSI, HPSI and CS pumps take their suction directly from the Safety Injection and Refueling Water Tank and have inlet pressures due to the level of water in the tank above the pump inlets. The pump inlet pressures will be calculated based on the tank l level and the difference in elevation between the tank and the pump inlets. Pump differential pressures will then be calculated by subtracting the calculated inlet pressure from the measured discharge pressures. Since the Safety Injection and Refueling ;
Water Tank provides the required positive pressure at the suction of the pumps and since the tank level does not significantly change when a pump is started, the calculated pump inlet pressure prior to starting a pump is the same as with a pump nmning. Flow losses through the suction piping of these pumps are negligible. Since the losses would be the same from test to test, not including them in the test would still enable pump degradation to be identified.
i The Boric Acid Pumps take their suction directly from the Boric Acid Tanks and have an inlet pressure due to the level of acid in the tanks above the pump inlet. The pump l
inlet pressure will be calculated based on the Boric Acid Storage Tank level and the elevation difference between the tank level and the pump inlet. Pump differential pressure will then be calculated by subtracting the calculated inlet pressure from the measured discharge pressure.
2.1.1.1.2 Evaluation--OM-6 does not require the measurement of pump inlet pressure as a separate parameter. However, Subsection 4.6.2.2 requires that differential pressure be determined using a gauge or differential pressure transmitter that provides a direct measurement of the pressure difference between the pressure at a point in the inlet pipe and the pressure in the discharge pipe. The Code requires measurement of differential pressure to help assess pump hydraulic condition and detect degradation.
The differential pressure of these pumps cannot be directly measured because there are no installed direct reading differential pressure or inlet pressure instruments. The raw water pumps are submerged and inaccessible, so direct reading inlet pressm e sensors can not be installed. In addition, significant system modifications would be necessary to provide direct measurement of differential pressure on all of the listed pumps. The inlet pressure of these pumps is due to the head of water above the level of the pump suction. The licensee's proposal to determine inlet pressure by measuring the height of fluid above the pump suction and to calculate differential pressure using this inlet pressure and the measured discharge pressure should allow them to adequately assess pump hydraulic condition and degradation.
However, the calculations should be within the accuracy that would result from installed instrumentation meeting the Code accuracy requirements. Requiring the licensee to make system modifications to directly measure pump differential pressure would be a hardship and it would provide only a limited amount of additional information.
If the differential pressure determination is within the accuracy that would result from installed instrumentation meeting the Code accuracy requirements, the calculated differential pressure in conjunction with the measured flow rate should provide adequate information for monitoring the hydraulic condition of the pump and permit detection of degradation.
Therefore, the proposed alternative should provide reasonable assurance of pump operational readiness.
Based on the determination that compliance with the Code requirements is a hardship without a compensating increase in the level of quality and safety, we recommend that the alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(ii).
2.2 Charcing Pumos 2.2.1 Pump Flow Rate Acceptance Criteria 2.2.1.1 Relief Request. Pump Relief Request E3 requests rehd from the flow rate acceptance criteria requirements of OM-6, Subsection 6.1 and Table 3b, for the charging pumps, CH-1 A, -1B, and -lC. The licensee proposes to not have an Alert Range for these pumps and to set the Required Action Range at <35 gpm and >40 gpm.
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2.2.1.1.1 Licensee's Basis for Recuestine Relief--The following text is quoted from pump relief request E3 in the Fort Calhoun Station Third Inspection Interval IST Program dated November 13, 1992:
There is no minimum now rate mentioned in the USAR for the charging pumps. A maximum flow rate of 40 gpm per pump is identified in the post-LOCA long term cooling section of the USAR. The reference flow rate value associated with these pumps is approximately 38 gpm. The charging pumps are positive displacement (reciprocating) type pumps. The flow rates for the charging pumps are established by the geometry of the positive displacement pump. The flow rate is a direct function of the amount of water displaced by the pump plungers with a constant speed pump.
AlMmate Testing: The discharge pressure for each pump will be set and recorded, then the Dow rate measured Quarterly. The acceptable range for flow will be 35 i Q 140. The " Required Action" range will be < 35 gpm and > 40 gpm. It is not crucial to double the frequency as flow rates approach 35 gpm because there is no minimum required flow rate given in the USAR, and unless instrumentation has drifted out-of-calibration or test conditions have changed, the Dow rate should not increase.
2.2.1.1.2 Evaluation--OM-6, Subsection 6.1, requires that when test measurements fall within the Alert Range limits of Table 3, the frequency of testing be doubled until the cause of the deviation is determined and the condition is corrected. This corrective action is required because entering the alert range indicates significant pump degradation or problems that warrant concern and more frequent testing to monitor pump condition, but the condition is not yet severe enough to require declaring the pump inoperable.
The licensee proposed to use alternate acceptance criteria to evaluate the charging pump flow rates. The following compares the licensee's proposed alternate against the Code acceptance criteria given a reference flow rate of 38 gpm:
Acceptable Range Alert Range Required Action Range Code Ranges 36.1 to 41.8 gpm* 35.3 to 36.1 gpm < 35.3 gpm,
> 41.8 gpm*
Proposed Ranges 35.0 to 40.0 gpm None < 35.0 gpm, > 40.0 gpm
'This is the Required Action Range, high, limit as determined from Table 3b, however, operational constraints for reasons other than IST may limit flow rate to a lower value.
The proposed Required Action Ranges do not differ significantly from the Code ranges, however, the proposed Acceptable and Alert Ranges are non-conservative in comparison with the Code requirements. The licensee's justification supporting this deviation from the Code is that there is no minimum flow rate mentioned in the USAR for the charging pumps.. However, the criteria of Table 3 are not based on specified system operational requirements, they are based on an amount of pump degradation that causes concem about pump operational readiness. These limits should not be ignored unless it can 5
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be shown that they may not be indicative of pump degradation that could increase the likelihood of the pump not being capable of performing its safety function if called on to do so.
Based on the determination that the licensee has not shown that compliance with the Code requirements is impractical, a hardship without a compensating increase in the level of quality and safety, or that the proposed alternative provides an equivalent level of quality and ,
safety as provided by the Code; we recommend that relief be denied. j r
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- 3. VALVE TESTING PROGRAM The following relief requests are evaluated against the requirements of the 1987 Edition,1988 Addenda, of the O&M Code, Part 10; 10 CFR 50.55a; and applicable NRC positions and guidelines. A summary and the licensee's basis for each relief request is presented followed by an evaluation and the reviewer's recommendation. Relief requests are grouped according to system and Code Category.
3.1 Various Systems 3.1.1 Thermal Relief Valves 3.1.1.1 Relief Request. Valve Relief Request G1 requests relief from the scope of OM-1, Subsection 1.1, for thermal relief valves on safety-related systems. The licensee proposes to control the testing of these valves under their preventive maintenance program.
3.1.1.1.1 Licensee's Basis For Requestine Relief--The following text is quoted from relief request G1 in the Fort Calhoun Station Third Inspection Interval IST Program dated November 13, 1992:
The O&M Code Part I provides general requirements for periodic performance testing and monitoring of pressure relief devices utilized in nuclear power plant systems which are required to perform a specific function in shutting down a reactor or in mitigating the consequences of an accident. Thermal relief valves will not be tested in accordance with O&M Part I guidance as part of the FCS ISI Program Plan, as FCS has determined that the thermal relief valves do not fully meet the intent of the scope of O&M Part 1. Many safety related systems, particularly those with heat exchangers, have been provided with relief valves. These relief valves are thermal relief valves of small capacity intended to relieve pressure due to a thermal expansion of fluid in a
" bottled up" condition, which is considered a self-limiting transient. Experience has shown that failure of these valves will not result in a failure of the system to fulfill its i safety function. Thus, most thermal relief valves are not considered to perform a l function "important to safety", and as such have not been included in the FCS ISI Program Plan.
Alternate Testing: Tests and test frequency for thermal relief valves will be controlled under the FC Preventive Maintenance (PM) Program and be conducted in a similar manner as the FCS ISI Program Plan.
3.1.1.1.2 Evaluation--In Paragraph IWV-1100 of the 1986 edition of Section XI, the Code committee increased the scope of the valves subject to IST to include those valves which protect certain Code-Class safety-related systems from overpressure.
Pressure relief valves which are installed in the applicable systems to protect against overpressure may not typically perform a " safety-related" function. However, these valves are now required to be included in the IST program and be tested according to the schedules stipulated in OM-1-1981 or OM-1-1987 " Requirements for Inservice Performance Testing of Nuclear Power Plant Pressure Relief Devices." ,
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Thermal relief valves installed to protect portions of safety-related systems against overpressure may be included in this expanded scope. The relief valves that may be involved are those that meet the following criteria: a) they protect a portion of a safety-related system, b) the protected piping and/or component may be isolated during a plant operating mode where credit is taken for operation of the safety-related system, c) the protected section is subject to a mechanism that could overpressurize it when isolated, and d) the integrity of the protected section (e.g., the absence of a rupture or stuck open relief ;
valve) is required for the system to meet its safety function. A failure of the relief valve to protect the safety-related system under these conditions could result in an undetected failure of the isolated section of the system that renders it inoperable. Valves that protect portions of safety-related systems that would not normally be isolated except for maintenance or other activities should not be included in the expanded scope. When these thermal relief valves are relied on to perform their function, the associated safety-related system is not in service and is not expected to be capable of performing its safety-related function until it has been tested and returned to service.
Because some of the thermal relief valves at Fort Calhoun Station may be included in the expanded scope as discussed above, we recommend that general relief not be granted as requested for all thermal relief valves. The licensee should justify exclusion of those thermal relief valves that do not protect portions of safety systems that may be isolated during a plant operating mode where credit is taken for operation of the safety-related system. Relief valves that protect portions of safety-related systems that may be isolated during a plant operating mode where credit is taken for operation of the system should be included in the IST program and tested to the Code requirements.
3.1.2 Leak Test Containment Isolation Valves (CIVs) 3.1.2.1 Relief Request. Valve Relief Request E5 requests relief from the leak rate testing requirements of OM-10, Subsection 4.2.2.2, for the CIVs listed in the relief request.
The licensee proposes to measure, record, and trend the leakage rate of these valves by penetration by pressurizing between the valves, which will apply pressure in the direction opposite to the design function for some of the valves.
3.1.2.1.1 Licensee's Basis For Requestine Relief--The following text is quoted from relief request E5 in the Fort Calhoun Station Third Inspection Interval IST Program dated November 13, 1992:
These valves are tested in accordance with 10 CFR 50, Appendix J by pressurizing between the valves as permitted by IWV-3424(b), versus pressurizing the valves iri the same direction as when the valves are performing their function as noted in IWV-3422. The valves cannot be tested in the direction of their design function due to system configuration, without extensive modifications to the piping system adjacent to each valve. These valves must be tested in pairs. Testing of these valves in the reverse direction results in higher leakage rates than testing in the accident direction.
This is a more conservative approach to testing. Testing between the valves does not allow leak rate trending by valve.
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l Alternate Testing: The valves marked with an asterisk will be leak tested in the direction opposite to the design function but in accordance with 10 CFR 50, Appendix J. Leak rates will be measured, recorded and trended by penetration.
3.1.2.1.2 Evaluation--OM-10, Paragraph 4.2.2.2, states: " Category A valves, ;
which are containment isolation valves, shall be tested in accordance with Federal Regulation i 10 CFR 50, Appendix J. Containment isolation valves which also provide a reactor coolant system pressure isolation function shall additionally be tested in accordance with para.
4.2.2.3." The NRC approved the use of OM-10 for CIVs with exceptions that require !
analysis of leakage rates and corrective actions in accordance with the requirements of l Paragraphs 4.2.2.3(e) and (f) (see 57 FR 34666, August 6,1992). i Appendix J states that: "The pressure shall be applied in the same direction as that when the valve would be required to perform its safety function, unless it can be determined that the results from the tests for a pressure applied in a different direction will provide equivalent or more conservative results." The licensee indicates in their basis for justi6 cation that " testing of these valves in the reverse direction results in higher leakage rates than testing in the accident direction." Therefore, it appears that the licensee is complying with the test pressure direction provisions of Appendix J, and relief is not required from these requirements.
Leak rate testing CIVs by penetration is permitted by Appendix J. Applying the analysis of leakage rates and corrective actions requirements of Paragraphs 4.2.2.3(e) and (f) does not prevent this test methodology, because both paragraphs establish requirements for ,
both specific " valves or valve combinations." Since testing valve combinations is permitted l by Appendix J and the applicable Paragraphs of OM-10, reliefis not necessary for this test method as long as it is performed in accordance with all other applicable requirements of Appendix J and OM-10.
3.2 Safety Iniection Systems 1
3.2.1 Cateeory A/C Valves 1
3.2.1.1 Relief Recuest. Valve Relief Request El requests relief from the exercising ;
frequency requirements of OM-10, Subsection 4.2.1.2, for the safety injection refueling water tank discharge check valves, SI-139 and -140. The licensee proposes to disassemble and inspect these valves once every other refueling outage.
3.2.1.1.1 Licensee's Basis For Requestine Relief--The following text is quoted from relief request El in the Fort Calhoun Station Third Inspection Interval IST Program dated November 13, 1992:
These check valves function to prevent backflow to the Safety Injection and Refueling Water Tank (SIRWT). These check valves are located in the lines leading from the SIRWT to the suctions of the Containment Spray (CS) pumps, the IAw Pressure l Safety Injection (LPSI) pumps and the High Pressure Safety Injection (HPSI) Pumps.
The check valves under certain accident conditions must open sufficiently to provide design basis flow to all of these pumps. Because of this requirement the system 9
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design full-stroke exercising of these check valves Quarterly or during Cold Shutdowns cannot be performed. During power operation, no full flow path exists for the combination of pumps because the HPSI and LPSI pumps cannot overcome the RCS pressure, and the CS system cannot be permitted to spray down the Containment. No full flow path is available during Cold Shutdowns because operating the HPSI pumps could create a low-temperature overpressurization condition in the RCS. CS cannot be used because the Containment would be sprayed down. Additionally it is not possible to achieve the maximum design accident Dow through the check valves during full Dow exercising.
The corrective maintenance history of these two check valves has been limited to gasket / bolt / nut replacements since installation. In addition, the check valves are 20 inch stainless steel Mission-Duochek type valves which see very little flow during ;
normal operations. OPPD has previously disassembled and inspected each of these check valves once with the results being that the check valves were "like new". The industry has experienced no failures with these type of check valves in similar applications at other facilities. The disassembly and subsequent inspection of these 1 valves requires unnecessary radiation exposure as well as creating significant (i.e.,
greater than 50 gallons) liquid radwaste requiring disposal. Also, frequent j disassembly and reassembly of the valves (i.e., every Refueling Outage) introduces !
unnecessary potential for valve failure due to damage caused by maintenance without l providing a commensurate increase in plant safety or check valve reliability.
Alternate Testine: OPPD will require check valves SI-139 and SI-140 to be alternately disassembled and inspected every other Refueling Outage. This sample i disassembly of these check valves is in accordance with the NRC guidelines I established in Generic 1.etter 89-04, Attachment 1, Position 2. This method of i sample disassembly and inspection will ensure that each check valve is disassembled j and inspected at least once every six years and will help to maintain personnel l exposure ALARA, while at the same time providing reasonable assurance that I integrity, quality and the ability to detect component degradation are maintained. )
1 3.2.1.1.2 Evaluation--The Code requires a full-stroke exercise of safety- I related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly, at cold shutdowns, or during refueling outages if quarterly full-stroke l exercising is impractical. This testing is to demonstrate that a valve is capable of moving to its safety function position (s) to assess its operational readiness. The licensee proposes to disassemble and inspect valves SI-139 and -140 on a sampling basis every other refueling outage (one valve will be disassembled every other refueling outage).
1 SI-139 and -140 are simple check valves in the suction lines for the ECCS pumps from the SIRWT. These valves do not have position indication, therefore, the only practicable conventional method of verifying a full-stroke exercise open is by verifying !
maximum design condition flow rate through them. It is impractical to verify design accident flow through these valves at any frequency because this would require simultaneously establishing LPSI and HPSI Dow into the reactor coolant system (RCS) and CS flow into the CS headers. It is impractical to establish Dow into the CS headers because this would result in spraying the containment, which could damage equipment inside 10
containment. The LPSI and HPSI pumps cannot establish Dow into the RCS during power operations because they do not develop sufficient head to overcome normal operating RCS pressure. It is impractical to establish LPSI and HPSI injection flow into the RCS during cold shutdowns because this could cause or contribute to low-temperature overpressurization of the RCS. The LPSI, HPSI, and CS pumps can be tested at full or substantial flow during refueling outages, however, it is impractical to establish the test flow paths that permit all of these pumps to simultaneously take their suction from the SIRWT through valves SI-139 and
-140. Since it is impractical to verify design accident flow through these valves, the I licensee's proposal to disassemble and inspect them may be the only practicable method to )
periodically verify their full-stroke exercise capability. The proposed method is permitted by OM-10, Paragraph 4.3.2.4(c), however, the proposed test frequency is not in accordance with OM-10.
Paragraph 4.3.2.4(c) permits the use of check valve disassembly every refueling j outage as an alternative to exercising. GL 39-04, Position 2, permits the use of a sampling i program for identical valves in similar applications. GL 8944 also provides a mechanism )
for extending the valve disassembly interval in cases of extreme hardship. The licensee's l basis supports extending the disassembly interval based on the low failure rate of these '
specific valves and similar valves in the nuclear industry. However, the criteria for l extending the interval in GL 89-04 requires the licensee to disassemble and inspect each j valve in the group and to document in detail the valve condition and its capability of being full-stroke exercised. The request indicated that each valve had been disassembled and found to be "like new." Stating that a valve is "like new" may be a subjective evaluation unless supported by a quantitative assessment such as taking critical dimension measurements and comparing them with new valve baseline measurement data. The GL 89-04 interval extension criteria do not provide specific evaluation requirements (e.g., trending critical dimension measurements), however, the licensee's evaluation should be adequate to provide reasonable assurance that degradation is not occurring in the group valves at a rate that could result in a valve becoming incapable of performing its function prior to the next examination.
The GL 8948 interval extension criteria also require a review of the installation of each valve addressing the "EPRI Applications Guidelines for Check Valves in Nuclear Power Plants." It is not clear from the relief request that this review has been performed and that the installation of these valves is satisfactory from that respect.
In the past several years there has been substantial development and refinement of alternate techniques for testing check valves. Therefore, some test method may be feasible to verify the full-stroke open capability of valves SI-139 and -140 in lieu of disassembly and inspection. The licensee should consider methods such as using non-intrusive techniques (e.g., acoustics, ultrasonics, magnetics, radiography, or thermography) to verify a full-stroke of these check valves. This testing may only be practical at refueling outages. The licensee should perform their investigation and if a test method is found to be practicable, the IST requirements for valves SI-139 and -140 should be satisfied by testing instead of disassembly and inspection.
Disassembly and inspection is permitted by OM-10 and relief is granted to perform it on a sampling basis by GL 89-04, therefore, these valves may be disassembled and inspected every refueling outage on a sampling basis provided that it is performed in accordance with 11 l l
l all of the provisions of GL 89-04. In addition, the disassembly interval may be extended if all of the interval extension criteria of GL 89-04, Position 2, are met.
3.2.2 Category C Valves 3.2.2.1 Relief Request. Valve Relief Request E2 requests relief from the exercising frequency requirements of OM-10, Subsection 4.2.1.2, for the ECCS pump suction check valves from the containment sump, SI-159 and -160. The licensee proposes to disassemble and inspect these valves once every other refueling outage.
3.2.1.1.1 Licensee's Basis For Requestine Relief--The following text is quoted from relief request E2 in the Fort Calhoun Station Third Inspection Interval IST i Program dated November 13, 1992- l These valves function to prevent backflow to the Containment lower level. These l valves are backed up by motor operated isolation valves HCV-383-3 and HCV-383-4 which are normally closed, fail-as-is, and open only upon receipt of a containment Recirculation Actuation Signal (RAS). Due to system design, these valves cannot be partial-stroke or full-stroke exercised open during power operation, Cold Shutdown or l Refueling Outage because the Containment sump is normally dry and there is no flow path available for testing. Full-stroke exercising these valves open requires that the l Containment sump be filled with water and provided with a source of makeup water I in addition to operating the CS pumps and the HPSI pumps at rated capacity.
l Therefore, system configuration renders flow testing of these valves impractical.
The corrective maintenance history of these two check valves has been limited to gasket / bolt / nut replacements since installation. In addition, the check valves are 24 l inch stainless steel Mission-Duochek type valves which see no flow during normal operations. OPPD has previously disassembled and inspected each of these check valves with the results being that the check valves were "like new". The industry has experienced no failures with this type of check valves in similar applications at other ;
facilities. The disassembly and subsequent inspection of these valves requires j unnecessary radiation exposure as well as creating significant (i.e., greater than 50 gallons) liquid radwaste requiring disposal, with minimal benefits. Also, frequent ,
disassembly and reassembly of the valves (i.e., every Refueling Outage) intrMuces I unnecessary potential for valve failure due to damage caused by maintenance Mout l providing a commensurate increase in plant safety or check valve reliability.
l Alternate Testing: OPPD will require check valves SI-159 and SI-160 to be alternately disassembled and inspected every other P Aeling Outage. This sample disassembly of these check valves is in accordance a.n the NRC guidelines i established in Generic letter 89-04, Attachment 1, Position 2 with the exception of l partial-stroke exercising. This method of sample disassembly and inspection will ensure that each check valve is disassembled and inspected at least once every six years and will help to maintain personnel exposure ALARA, while at the same time providing reasonable assurance that the integrity, quality and the ability to detect component degradation is maintained.
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3.2.1.1.2 Evaluation--OM-10 requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly, at cold shutdowns, or during refueling outages if quarterly full-stroke exercising is impractical. This testir.g is to demonstrate that a valve is capable of moving to its safety function position (s) to assess its operational readiness. The licensee proposes to disassemble and inspect valves SI-159 and -160 on a sampling basis every other refueling outage (i.e., one valve will be disassembled every other refueling outage).
SI-159 and -160 are simple check valves in the suction lines for the ECCS pumps from the containment sump. These valves do not have position indication, therefore, the only practicable conventional method of verifying a full-stroke exercise open is by verifying maximum design condition flow rate through them. It is impractical to verify design accident flow through these valves at any frequency because this would require filling the containment sump with water and simultaneously establishing IC'SI flow into the RCS and CS flow into the CS headers. It is impractical to establish flow into the CS headers because this would result in spraying the containment, which could damage equipment inside containment. The HPSI pumps cannot establish flow into the RCS during power operations because they do not develop sufficient head to overcome normal operating RCS pressere. It is impractical to establish HPSI injection flow into the RCS during cold shutdowns because this could cause or contribute to low-temperature overpressurization of the RCS. The HPSI and CS pumps can be tested at full or substantial flow during refueling outages, however, it is impractical to establish the test flow paths that permit all of these pumps to simultaneously ,
take their suction from the containment sump through valves SI-159 and -160. Since it is impractical to verify design accident flow through these valves, the licensee's proposal to disassemble and inspect them may be the only practicable method to periodically verify their full-stroke exercise capability. The proposed method is permitted by OM-10, Paragraph 4.3.2.4(c), however, the proposed test frequency is not in accordance with OM-10.
Paragraph 4.3.2.4(c) permits the use of check valve disassembly every refueling outage as an alternative to exercising. GL 89-04, Position 2, permits the use of a sampling program for identical valves in similar applications. GL 89-04. also provides a mechanism for extending the valve disassembly interval in cases of extreme hardship. The licensee's ,
basis supports extending the disassembly interval based on the low failure rate of these '
specific valves and similar valves in the nuclear industry. However, the criteria for extending the interval in GL 89-04 requires the licensee to disassemble and inspect each valve in the group and to document in detail the valve condition and its capability of being full-stroke exercised. The request indicated that each valve had been disassembled and found to be "like new." Stating that a valve is "like new" may be a subjective evaluation unless !
supported by a quantitative assessment such as taking critical dimension measurements and :
comparing them with new valve baseline measurement data. The GL 89-04 interval l extension criteria do not provide specific evaluation requiremena (e.g., trending critical dimension measurements), however, the licensee's evaluation should be adequate to provide reasonable assurance that degradation is not occurring in the group valves at a rate that could result in a valve becoming incapable of performing its function prior to the next examination.
The GL 89-04 interval extension criteria also require a review of the installation of eau.
valve addressing the "EPRI Applications Guidelines for Check Valves in Nuclear Power Plants." The request does not indicate that this review has been performed and that the installation of these valves is satisfactory from that respect.
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in the past several years there has been substantial development and refmement of alternate techniques for testing check valves. Therefore, some test method may be feasible to verify the full-stroke open capability of valves SI-159 and -160 in lieu of disassembly and inspection. The licensee should consider methods such as using non-intrusive techniques ;
(e.g., acoustics, ultrasonics, magnetics, radiography, or thermography) to verify a full-stroke i of these check valves. This testing may only be practical at refueling outages. The licensee should perform their investigation and if a test method is found to be practicable, the IST ,
requirements for valves SI-159 and -160 should be satisfied by testing instead of disassembly l and inspection. 1 Disassembly and inspection is permitted by OM-10 and relief is granted to perform it on a sampling basis by GL 89-04, therefore, these valves may be disassembled and inspected every refueling outage on a sampling basis provided it is performed in accordance with all of l the provisions of GL 89-04. In addition, the disassembly interval may be extended if all of l the interval extension criteria of GL 89-04, Position 2, are met. l The licensee states in their proposed alternate testing that "the sample disassembly of )
these check valves is in accordance with the NRC guidelines established in Generic I.etter l 89-04, Attachment 1, Position 2 with the exception of partial-stroking." Position 2 states l
that "if possible, partial valve stroking quarterly or during cold shutdowns, or after '
reassembly must be performed." Not performing part-stroke exercising in accordance with Paras. 4.2.1.2(b) and (d) is acceptable if the licensee identifies the technical basis explaining why this testing is impractical. However, the part-stroke exercise after reassembly required l by Position 2 is to demonstrate that the maintenance procedure (i.e., disassembling a valve l and reassembling it) has been performed in a manner that has not rendered the valve i incapable of performing its function. Not performing some form of post maintenance testing to verify proper reassembly of these valves following their disassembly and inspection is unacceptable. If a part-stroke exercise following reassembly is impractical, this should be ;
identified in the program and an alternate proposed that offers reasonable assurance of the !
valve's operational readiness following the maintenance procedure. The post maintenance testing requirements of OM-10, Para. 3.4, must be met for the disassembly and inspection activity unless specific relief is requested and approved.
3.3 Containment Sprav System l 3.3.1 Category C Valves i
3.3.1.1 Relief Request. Valve Relief Request E3 requests relief from the exercismg i frequency requirements of OM-10, Subsection 4.2.1.2, for the containment spray header l check valves, SI-175 and -176. The licensee proposes to disassemble and inspect these valves once every other refueling outage. 1 3.3.1.1.1 Licensee's Basis For Recuesting Relief--The following text is quoted from relief request E3 in the Fort Calhoun Station Third Inspection Interval IST ,
Program dated November 13, 1992: l These cheek valves are located inside Containment. These valves cannot be full-stroke or partial-stroke exercised onen using system flow during any plant 14 i
operating conditions because the only flow path is into the CS headers and would resui in spraying down the Containment, causing equipment damage and requiring extensive cleanup.
The corrective maintenance history of these two check valves has been limited to gasket / bolt / nut replacements since installation. In addition, the check valves are 12 inch stainless steel Mission-Duochek type valves which see no flow during normal operations. OPPD has previously disassembled and inspected each of these check valves with the results being that the check valves were "like new". The industry has experienced no failures with this type of check valves in similar applications at other facilities. The disassembly and subsequent inspection of these valves requires unnecessary radiation exposure with minimal benefits. Also, frequent disassembly and reassembly of the valves (i.e., every Refueling Outage) introduces unnecessary potential for valve failure due to damage caused by maintenance without providing a commensurate increase in plant safety or check valve reliability.
Alternate Testine: Check valves SI-175 and SI-176 will be alternately disassembled every other refueling outage. The sample disassembly of these check valves is in accordance with the NRC guidelines established in Generic Letter 89-04, Attachment i 1, Position 2 with the exception of partial-stroking. This method of sample l disassembly and inspection will ensure that each check valve is disassembled and j inspected at least once every six years and will help to maintain personnel exposure ALARA, while at the same time providing reasonable assurance that the integrity, l quality and the ability to detect component degradation is maintained. I 3.3.1.1.2 Evaluation--OM-10 requires a full-stroke exercise of safety-related check valves quarterly, if practical, and provides a hierarchy for part and full-stroke exercising quarterly, at cold shutdowns, or during refueling outages if quarterly full-stroke exercising is impractical. This testing is to demonstrate that a valve is capable of moving to its safety function position (s) to assess its operational readiness. The licensee proposes to disassemble and inspect valves SI-175 and -176 on a sampling basis every other refueling outage (i.e., one valve will be disassembled every other refueling outage).
SI-175 and -176 are simple check valves in the CS lines to the spray headers inside containment. These valves do not have position indication, therefore, the only practicable conventional method of verifying a full-stroke exercise open is by verifying maximum accident condition flow rate through them. It is impractical to verify maximum accident flow through these valves at any frequency because the only full flow path through these valves is into the CS headers, therefore, this testing would require establishing full CS flow into the !
CS headers. Establishing flow into the CS headers would result in spraying the containment, I which could damage equipment inside containment. Since it is impractical to verify design accident flow through these valves, the licensee's proposal to disassemble and inspect them may be the only practicable method to periodically verify their full-stroke exercise capability.
The proposed method is permitted by OM-10, Paragraph 4.3.2.4(c), however, the proposed frequency is not in accordance with OM-10.
Paragraph 4.3.2.4(c) permits the use of check valve disas'sembly every refueling outage as an alternative to exercising. GL 89-04, Position 2, permits the use of a sampling 15
I 1
program for identical valves in similar applications. GL 89-04 also provides a mechanism for extending the valve disassembly interval in cases of extreme hardship. The licensee's basis supports extending the disassembly interval based on the low failure rate of these specific valves and similar valves in the nuclear industry. However, the criteria for extending the interval in GL 89-04 requires the licensee to disassemble and inspect each valve in the group and to document in detail the valve condition and its capability of being full-stroke exercised. The request indicated that each valve had been disassembled and found to be "like new." Stating that a valve is "like new" may be a subjective evaluation unless supported by a quantitative assessment such as taking critical dimension measurements and comparing them with new valve baseline measurement data. The GL 89-04 interval extension criteria do not provide specific evaluation requirements (e.g., trending critical dimension measurements), however, the licensee's evaluation should be adequate to provide reasonable assurance that degradation is not occurring in the group valves at a rate that could l
result in a valve becoming incapable of performing its function prior to the next examination.
The GL 89-N interval extension criteria also requia a review of the installation of each valve addressing the "EPRI Applications Guidelines for Check Valves in Nuclear Power Plants." It is not clear from the relief request that this review has been performed and that the installation of these valves is satisfactory from that respect.
In the past several years there has been substantial development and refinement of alternate techniques for testing check valves. Therefore, some test method may be feasible to verify the full-stroke open capability of valves SI-175 and -176 in lieu of disassembly and inspection. The licensee should consider methods such as using non-intrusive techniques (e.g., acoustics, ultrasonics, magnetics, radiography, or thermography) to verify a full-stroke of these check valves. This testing may be practical only at refueling outages. The licensee should perform their investigation and if a test method is found to be practicable, the IST requirements for valves SI-175 and -176 should be satisfied by testing instead of disassembly and inspection.
Disassembly and inspection is permitted by OM-10 and relief is granted to perform it on a sampling basis by GL 89-04, therefore, these valves may be disassembled and inspected every refueling outage on a sampling basis provided it is performed in accordance with all of the provisions of GL 89-N. In addition, the disassembly interval may be extended if all of the interval extension criteria of GL 89-N, Position 2, are met.
The licensee states in their proposed alternate testing that "the sample disassembly of these check valves is in accordance with the NRC guidelines established in Generic Letter 89-N, Attachment 1, Position 2 with the exception of partial-stroking." Position 2 states that "if possible, partial valve stroking quarterly or during cold shutdowns, or after reassembly must be performed." Not performing part-stroke exercising in accordance with Paras. 4.2.1.2(b) and (d) is acceptable if the licensee identifies de technical basis explaining why this testing is impractical. However, the part-stroke exercise after reassembly required by Position 2 is to demonstrate that the maintenance procedure (i.e., disassembling a valve and reassembling it) has been performed in a manner that has not rendered the valve incapable of performing its function. Not performing some form of post maintenance testing to verify proper reassembly of these valves following their disassembly and inspection is unacceptable. If a part-stroke exercise following reassembly is impractical, this should be identified in the program and an alternate proposed that offers reasonable assurance of the 16
)
valve's operational readiness following the maintenance procedure. The post maintenance testing requirements of OM-10, Para. 3.4, must be met for the disassembly and inspection activity unless specific relief is requested and approved.
3.4 Auxiliary Feedwater System 3.4.1 Category C Valves 3.4.1.1 Relief Request. Valve request E6 requests relief from the test frequency requirements of OM-1, Subsection 1.3.5(b), for the auxiliary feedwater pump oil cooler relief valve, FW-1525. The licensee proposes to test this valve every third refueling outage.
3.4.1.1.1 Licensee's Basis For Requestine Relief--The following text is quoted from relief request E6 in the F -t Calhoun Station Third Inspection Interval IST Program dated November 13, 1992:
The relief valve is the only one of its type and manufacturer in its respective group.
The intent of the Code is that all Class 3 relief valves be tested at least once every ten years (Reference O&M Part 1, Subsection 1.3.5(b)). This intent will be met. The current Refueling Outage frequency is 18 months. A review of historical maintenance records reveals that there have been no maintenance problems which justify testing th relief valve every other refueling outage. The scope of O&M Part 1 is to verify valve operability and detect any degradation in valve performance.
Alternate Tcling: The relief valve will be tested every third refueling outage. :
3.4.1.1.2 Evaluation-OM-1 establishes a sampling plan to test groups of relief valves of each type and manufacturer. The sampling plan requires part of the relief valves in a group to be tested during a time period (a minimum of 20% of the valves of each type and manufacturer within any 48 months) and requires testing of additional valves of that type and manufacturer if one or more of the tested valves fails the test. A sampling plan is used by OM-1 to eliminate the time, radiation exposures, etc. of testing 100% of the valves more frequently. The sampling technique allows this reduction in testing without a significant increase in the likelihood of an undetected failure. Proper operation of the valves in the test sample gives reasonable assurance that the other valves in the group are capable of performing their safety functions. Sampling provides this assurance because valves of the same type and manufacturer should be affected by the same degradation and failure mechanisms. Therefore, the testing of individual valves in the group can be reasonably extended to once every ten years because other valves from the group are being successfully tested more frequently. Testing a single valve once every ten years is not equivalent to testing a group of similar valves in a sampling plan as established by OM-1.
1 Relief valve FW-1525 is the only one of its type and manufacturer, therefore, it forms a one valve sample group. OM-1 requires a minimum of 20% of the valves of each type and 1 manufacturer be tested within any 48 months. Therefore, FW-1525 is required to be tested l every 48 months. The licensee proposes to test this valve once every third refueling outage. l They state that the current refueling outage frequency is 18 months, therefore, the minimum l time between tests of this valve would be 54 months. The 54 month period is not '
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significantly longer than the 48 month period, therefore, this extension may be acceptable depending on the failure and repair record of this valve. If this valves does not require frequent adjustments or repairs, testing at the proposed frequency should provide an acceptable level of quality and safety.
Discussions with members of the Working Group on Safety and Relief Valves (OM-1) indicate that the working group did not consider one valve groups when writing the Code. It is the impression of the working group members contacted, that the working group's intent is to have this type of valve tested at least once every ten years. The working group will meet on June 20 and 21,1994, and will include this issue on their agenda.
Based on the determination that the proposed alternate is not significantly different from the Code requirements and that it should provide reasonable assurance of valve operational readiness during the interim period; we recommend that the alternative be ,
authorized pursuant to 10 CFR 50.55a(a)(3)(i) until the OM-1 Working Group clarifies this issue. After the working group has clarified their position on this issue, the licensee should either modify or delete relief request E6.
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- 4. DEFERRED TEST EVALUATIONS The following relief requests and deferred test justifications involve the frequency of testing safety-related valves. These requests and justifications are listed in Table 4.1 and are evaluated in accordance with the exercising frequency requirements of OM-10 Paragraph 4.2.1.1 or 4.3.2.1 as discussed below.
4.1 Bases for Deferrine Valve Exercisine Section XI, Paragraphs IWV-3411 and -3521, specifies that valves be exercised every three months except as provided by Paragraphs IWV-3412 and -3522, respectively.
Paragraphs IWV-3412 and -3522 permit valve full-stroke exercising to be deferred until cold shutdowns if full-stroke operation is impractical during plant operation.
In rulemaking to 10 CFR 50.55a effective September 8,1992, the 1989 Edition of ASME Section XI was incorporated in 10 CFR 50.55a(b). The 1989 Edition of Section XI provides that the rules for inservice testing of valves are as specified in OM-10.
10 CFR 50.55a(0(4)(iv) provides that IST of valves may meet the requirements set forth in subsequent editions and addenda that are incorporated by reference in 10 CFR 50.55a(b),
subject to the limitations and modifications listed, and subject to NRC approval. Portions of editions or addenda may be used provided that all related requirements of the respective editions or addenda are met.
OM-10, Paragraphs 4.2.1.2 and 4.3.2.2, permit deferral of full-stroke exercising until refueling outages when this exercising is not practicable during plant operation or cold shutdowns. The NRC staffimposed no limitations to OM-10 associated with the test frequency requirements. However, to utilize this provision of OM-10, the licensee must implement all related requirements, which include Paragraphs 4.3.2.2(h) and 6.2.
4.2 Conclusion l
For all of these relief requests and deferred test justifications where the licensee has demonstrated the impracticality of full-stroke exercising the listed valves quarterly and/or during cold shutdowns, deferral of this testing until cold shutdowns or refueling outages is covered by Section XI and/or OM-10. Accordingly, the licensee's proposed alternate testing is in compliance with either the Code or the rulemaking effective September 8,1992. l Therefore, we recommend that the proposed alternatives be approved pursuant to 10 CFR 50.55a(f)(4)(iv). If testing is deferred until refueling outages in accordance with OM-10, the licensee must implement all related requirements, which include Paragraphs 4.3.2.2(h) and 6.2. Whether all related requirements are met is subject to NRC inspection.
Cases where the licensee has not adequately demonstrated the impracticality of full stroke exercising these valves quarterly and/or during cold shutdowns, are identified in Table 4.1 and in anomalies in Appendix A to this report.
Where full-stroke exercising is impractical quarterly and/or during cold shutdowns,Section XI and OM-10 require part-stroke exercising quarterly and/or during cold shutdowns if practical. Where full-stroke exercising is deferred until cold shutdowns or refueling 19
1 outages, the licensee should part-stroke exercise the applicable valves as specified by OM-10, Paragraph 4.2.1.2 or 4.3.2.2, as appropriate.
4.3 Disassembly and Insoection Several of the licensee's deferred test justifications propose check valve disassembly and inspection in lieu of full-stroke exercising the applicable valves open and/or closed with i system pressure or flow. These are valves that cannot practically be verified to full-stroke exercise open and/or closed using system pressure or flow. Therefore, the staff approved the use of disassembly and inspection during refueling outages in GL 89-04 for those cases where it is impractical to verify a full-stroke exercise by testing.
OM-10, Paragraph 4.3.2.4(c), permits the use of disassembly and inspection to verify check valve obturator movement. This testing is to be performed at refueling outages, however, no provisions are made to allow using a sampling program. GL 89-04, Position 2, provides guidelines for check valve disassembly and inspection on a sampling basis. This -
technique is approved for groups of identical valves in similar applications provided that it is performed in accordance with all of the provisions of the generic letter. This topic is also addressed in Appendix A, Items 3 and 4.
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Table 4.1 DEFERRED TEST EVALUATIONS FORT CALHOUN STATION Itern Valve Justification for Deferring Valve Proposed Alternate Evaluation of Lmber Identification Exercising Testing Licensee's i Justification i
Jl HPSI pump These valves cannot be full-stroke Valves will be partial-stroke Full-stroke exercising suction check exercised open quarterly during plant exercised using the these valves open I valves: operation or dunng cold shutdowns, minimum recirculation flow quarterly or during '
SI-100 and -113 smce to do so would require a flow path quarterly during cold shutdowns is path to the RCS. That flow path normal operations, and impractical.
cannot be utilized during power full-stroke exercised open Therefore, the operation because the HPSI pumps do during refueling outages. alternate is in not develop sufficient discharge This method of accordance with i pressure to overcome RCS pressure, partial-stroke exercising OM-10, Para. 4.3.2. l This same flow path cannot be quarterly and full-stroke ;
utilized during cold shutdowns exercising open during because there is insufficient volume refueling outages is in in the RCS to accommodate the flow accordance with the required and a low temperature guidance set forth in overpressure condition of the RCS OM-10, Para. 4.2.1.2.
could result.
12 Pressurizer These valves can only be opened or The PORVs will be stroke- It is impractical to L power operated closed when there is a pressure timed in the open and exercise these valves relief valves differential across the valve. The closed direction during the quarterly. Therefore, (PORVs): valves have solenoid pilot valves that transition to cold shutdown the alternate is in PCV-1021 and control their actuation. Since valves (primary plant pressure is accordance with
-102-2 of this type have a history in the between 350 - 450 psis and OM-10, Para. 4.2.1.
industry of sticking open and the primary plant temp *erature is PORVs are not credited in the safety between 300 - 350 F) prior analysis for overpressure protection to entering Mode 4. The during power operations it is PORVs will be tested impractical to stroke these valves during the transition from quarterly during power operation. hot shutdown to cold These valves cannot be partial-strol e shutdown, as defined by tested because they are either fully FCS TS whenever practical, opened or fully closed. i.e., normal plant shutdown. During a TS mandated shutdown, the PORVs will be tested during plant startup prior to entenng Mode 2 (wben primary plant pressure is between 350 - 450 psia and primary plant temp *erature is between 300 - 350 F).
B 4
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s Itan Valve Justification for Deferring Valve Proposed Alternate Evaluation of i Number Identification Exercising Testing Licensee's Justification 13 HPSI pump These valves cannot be full-stroke or Valves will be full-stroke Full-stroke exercising discharge check partial-stroke exercised open during exercised open during these valves open -
valves: plant operation, refueling outages when the quarterly or during SI-102, -108, cold shutdowns, quarterly since to do so or duringreactor vessel head is would cold shutdowns is and -115 require a flow path to the RCS. That removed. This will provide impractical.
flow path cannot be utilized during an expansion volume to Therefore, the power operation because the HPSI accommodate the flow alternate is in pumps do not develop sufficient required. accordance with discharge pressure to overcome RCS OM-10, Para. 4.3.2, pressure. This same flow path cannot be utilized during cold shutdowns because there is insufficient volume in the RCS to ,
accommodate the flow required, and a low-temperature overpressure condition of the RCS could result.
Additionally, these valves cannot be i exercised during quarterly pump tests or miniflow because the minimum flow lines branch off upstream of the check valves and no flow occurs through these valves.
34 LPSI pump These valves cannot be partial-stroke Valves will be full-stroke Exercising these valves discharge check or full-stroke exercised m the open exercised open during cold open quarterly is valves: direction quarterly during power shutdown. impractical.51-121 and -129 operation because there is no flow Therefore, the path available except during shutdown alternate is in cooling. Additionally, these valves accordance with cannot be exercised open during OM-10, Para. 4.3.2.
quarterly pump tests or using the miniflow line because the nunimum flow lines branch off upstream of the ~
check valves and no flow occurs through these valves.
J5 Charging pump These check valves serve to permit Valves will be full-stroke Exercising these valves .
bone acid direct feed of concentrated boric acid exercised open during open quarterly is supply check solution to the charging pump suction refueling outages. impractical, therefore, valve: header. These check valves cannot deferring exercising CH-143 be full-stroke or partial-stroke until cold shutdowns is Charging pump exercised quarterly during power in accordance with boric acid operation or cold shutdown. He OM-10, Para. 4.3.2.
l gravity feed only flow path through these valves is However, J5 does not check valve: into the RCS exercising would result adeguately demonstrate ininj CH-155 the impracticality of at Charging pump acid mecting highly to the RCS. concentrated boric Injecting least part-stroke safety injection concentrated boric acid into the RCS exercismg these valves and refueling during power operation could cause a when borating the RCS ,
water tank reactivity excursion or a plant while going into cold (SIRWT) shutdown. Injecting concentrated shutdowns (see suction check boric acid into the RCS during cold Appendix A, Item 7).
valve: shutdown could delay reactor startup CH-156 because of the requirement to establish the proper boron concentration pnor to the reactor startup.
t 22
s Item Valve Justification for Deferving Valve Proposed Alternate Evaluation of Number Identification Exertising Testing Licensee's Justification 16 Steam generator These check valves function to Valves will be full-stroke Exercising these valves normal prevent the loss of inventory of the exercised closed during cold closed quarterly is feedwater inlet steam generators in the event of a shutdown as defined in the impractical.
check valves: line break upstream between valves FCS TS, provided the Herefore, the FW-161 and HCV-1386 (HCV-1385) and check feedwater system is able to alternate is in
-162 valve FW-161 (FW-162). These be isolated from the steam accordance with check valves cannot be full-stroke generator and the feedwater OM-10, Para. 4.3.2.
exercised closed quarterly during imes are able to be drained (See Appendix A, power o ration because the only as required to permit Item 9) llow pa are into the steam testmg.
generators. During power operation, the feedwater paths to the steam generators must not be isolated as this would remove the " heat sink" for the RCS.
17 Steam generator Dese check valves open for auxiliary These check valves are Exercising these valves auxiliary feedwater flow to the steam exercised open during cold closed quarterly is feedwater generators. Exercising these valves shutdown. Since failure of impractical.
injection check during power operation would result these valves to function in herefore, the valves: in cold water injection to a portion of the reverse flow direction alternate is in FW-163 and the steam generators normally at 400 would not interfere with the accordance with
-164 to 500*F, which would cause plant's ability to shutdown OM-10 Para. 4.3.2.
unnecessary and possibly damaging or to nutigate the (See Appendix A, thermal stresses in the steam consequences of an Item 10) generators. accident, these check valves shall be full-stroke exercised only in the open direction.
18 Reactor vessel These valves are intended to be used These valves will be Exercising these valves head and to vent the reactor pressure vessel stroke-timed in the open quarterly is pressunzer vent head and pressurizer. These valves and closed directions during impractical, therefore, valves: are Target Rock solenoid valves, refueling outages, deferring exercising HCV-176, which have a history of sticking open until cold shutdowns is
-177, -178, when exercised. This could result m in accordance with
-179, -l 80, and a small break LOCA if these valves OM-10, Para. 4.2.1.
-181 are stroke-timed at power or at cold However, the DTJ shutdown. Therefore, partial or does not adequately full. stroke timing dunng normal demonstrate the operation or cold shutdown is impracticality of impractical. exercising these valves during cold shutdowns (see Appendix A, Item 7).
19 Shutdown These check valves cannot be These check valves are Exercising these valves l cooling full-stroke exercised o or full-stroke exercised open open quarterly is injection check partial-stroke exerci quarterly during cold shutdown when impractical.
valves: during power operation because no the shutdown cooling Therefore, the l SI-194, -197, flow path is available at operating system is in service. These alternate is in 1
-200, and 203 pressure due to system configuration. check valves will be leak accordance with l Since the 51 pumps are not able to tested during cold shutdown OM-10, Para. 4.3.2. i develop sufficient discharge pressure in accordance with the '
to overcome RCS pressure, the requirements of FCS i valves are not able to be exercised. TS 2.1. Table 2-9, and Item i Valves S1-194, -197 -200 and -203 14 of the table format of l are pressure isolation valves as the FCS Program Plan.
defined by NRC GL 89-04 and as listed in the FCS TS.
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4 Itern Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Lice:6ee's Justification 110 HPSI to reactor These check valves cannot be These check valves will be Full-stroke exercising coolant loop full-stroke or partial-stroke exercised full-stroke exercised open these vahes open check valves: open quarterly during power during refueling outages quarterly or during
$1-195, -198, operation because the only flow path when the RCS is cold shutdowns is
-201, and .2N available is into the RCS. Since the depressurized and the impractical.
HPSI pumps do not develop sufficient reactor vessel head is Therefore, the discharge pressure to overcome RCS removed in order to p rovide alternate is in operating pressure, the valves cannot an expansion volume to accordance with be exercised during cold shutdown accommodate the flov OM 10. Para. 4.3.2.
because the RCS does not contain an required. Bene che;k adequate expansion volume and a low valves will be leak tested temperature overpressurization of the during cold shutdcrvn in RCS could result. Valves SI-195, accordance with tho
-198, -201 and -204 are pressure requirements of FCc3 TS isolation valves (PlVs) as defined by 2.1, Table 2-9, and nem 14 NRC GL 89-04 and as listed in the of the table format of the FCS TS. FCS Program Plan.
1 111 HPSI to reactor These valves function to prevent Check valve CH-469 will It is impractical to full coolant loop backflow through the SI pump be partial-stroke exercised or part-stroke exercise check valves: discharge headers. These valves open during cold shutdown these valves open SI-l %, -199, cannot be full-stroke or partial-stroke using the charging pu s. quarterly. Jll does
-202, -205, exercised open during power Both check valves CH 9 not provide a basis for
-343 and operation utilizing flow because the and SI-343 will be not full-stroke CH-469 HPSI pumps do not develop sufficient full-stroke exercised open exercising valves discharge pressure to overcome RCS during refueling outages SI-l%, -199, 202 and pressure, ne charging pumps using the chargmg pumps -205 at cold shutdowns cannot be used dunng power and the HPSI pumps as nor are these valves operation because the flow path from necessary. addressed in the the pumps would bypass the Alternate Testing. In regenerative heat exchanger and addition, J11 does not result in injecting cold water, causing provide a basis for not thermal shock to the injection nozzles full-stroke exercising and a reactivity transient. Check valve CH-469 valve SI-343 cannot be partial-stroke quarterly or at cold exercised during cold shutdowns shutdowns. All of because using the HPSI pumps could these valves should be tested asjustified in cause RCS; the an HP 1over$nressurization pumps are therefore of the accordance with tagged out to prevent inadvertent OM-10 Pa 4 4.3.2.
operation. (See Appe id.x A, Items 7 an ' 11).
J12 Chargmg pump These check valves cannot be ne check valves will be Full-stroke xercising discharge to full-stroke exercised open dunng partial-stroke exercised in these valvet open RCS check plant operations quarterly or dunng the open direction quarterly quarterly or odog valves: cold shutdowns, since to do so would during power operation cold shutdowns is CH-198, -203, r uire the charging and HPSI pumps using the chargmg pumps. impractical.
and -2N to run which would require a flow ne check valves will be Therefore, the path to the RCS. Hat flow path full-stroke exercised in the alternate is in cannot be utilized during power open direction during accordance with operation because the HPSI pumps do refueling outages when the OM 10, Para. 4.3.2. ;
not develop sufficient discharge reactor vessel head is pressure to overcome RCS pressure, removed, using the This same flow path cannot be charging pumps and the utilized during cold shutdowns HPSI pumps, because there is insufficient volume in the RCS to accommodate the flow required and a low-temperature overpressure condition of the RCS could result. .
t 24
Item Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's Justification J13 Letdown These valves are used for RCS Loop nese valves will be Exercising these valves temperature 2A, letdown isolation and stroke-timed in the closed closed quarterly is control and temperature regulation. Stroking direction during cold impractical.
isolation valves; these valves quarterly during power shutdown when the RCS is Berefore, the TCV-202 and operation could result in the depressurized. alternate is in HCV-204 termination ofletdown flow. This accordance with would isolate the RCS purification OM 10, Para. 4.2.1.
process and could potentially cause a (See Appendix A.
reactivity excursion. Bene valves Item 9) cannot be partial-stroked because the valves are either fully open or fully closed.
J14 Auxiliary This check valve cannot be full-stroke ne check valves will be Full-stroke exercising pressurizer exercised during plant operations partial-stroke exercised in this valve open spray check quarterly or dunng cold shutdowns, the open direction quarterly quarterly or during valve: since to do so would require a flow during power operation cold shutdowns is CH-205 path to the RCS. That flow path using the chargmg pumps. impractical.
cannot be utilized during power The check valves will be Therefore, the operation because the HPSI pumps do full-stroke exercised in the altemate is in not develop sufficient discharge open direction during accordance with pressure to overcome RCS pressure. refueling outages when the OM-10, Paru. 4.3.2.
His same flow path cannot be reactor vessel head is utilized during cold shutdowns removed, using the because there is insufficient volume charging pumps and the in the RCS to accommodate the flow HPSI pumps.
required and a low temperature overpressure condition of the RCS could result.
115 RCP control The Reactor Coolant Pump (RCP) The valves will be Exercising these valves bleedoff seals serve as an RCS pressure stroke-timed in the closed closed quarterly is isolation valves: boundary; therefore, seal failure direction during cold impractical.
HCV-206 and could result in unisolable coolant shutdown, when the RCS is Therefore, the
-241 leakage from the RCS. Isolation of depressurized and the RCPs attemate is in the RCP seal bleed-off by stroking are secured. accordance with these valves closed would cause the OM-10, Para. 4.2.1.
seal bleed-offline relief valve (CH-208) to lift, directing reactor coolant directly to the reactor coolant drain tank (RCDT). If the leakage i remained unchecked, the RCDT relief valve could lift directing reactor coolant to the containment floor, causing a ventilation isolation actuation si (VIAS).
Additionall , the temporary isolation of pump flow (until the relief valve lifted) would climinate the ability of the RCP seal to break down RCS pressure and could potentially cause localized overheating of the seals. The pump seals can be damaged by overheating if seal water flow is sto running. pped while the pumps areIt is impractical to exercise these valves quarterly or during any plant conditions that could result in abnormal seal wear. His could lead to failure of the RCP seals, creating unisolable leakage equivalent to a small break LOCA.
25 l
1 l
l Itan Valve Justification for Deferring Valve Propomi Altesnate Evaluation of Number Identification Exercising Testing Licensee's i Justification l 116 Volume control These valves function to provide Valve LCV-218-2 will be Exercising these valves tank (VCT) and VCT level control and switch stroke-timed in the closed quarterly is safety injection charging suction to the SIRWT. ne direction and valve impractical.
and refueling valves cannot be stroke-tested LCV-218-3 will be 'Ihrefore, the water tank quarterly because doing so would stroke-timed in the open alte. *u is in I (SIRWT) outlet tennmate charging flow to the RCS direction during cold accordance with l isolation valves: and would have the potential for shutdowns. OM-10, para. 4.3.2. 1 LCV-218-2 and disrupting pressunzer level regulation 1
-218-3 or boron concentration regulation. ;
Pressurizer level regulation disruption i can lead to RCS pressure transients 1 1 and disruption of boron concentration could cause reactivity excursions. j JI7 Auxiliary Valves HCV-240 and -249 cannot be Valve IA-HCV-240-C will Exercising these valves preuunzer stroke-timed quarterly during power be exercised in the open quarterly is spray isolation operation because domg so will lead and closed directions during impractical.
valves and the to large scale depressunzation of the ce3d shutdowns. Valves herefore, the instrument air RCS and thermal shock of the HCV-240 and HCV-249 alternate is in accumulator pressurizer spray nozzle. The IA wil; be stroke-timed in both accordance with check valve: accumulator check valve the open and close OM-10. Paras. 4.2.1 HCV-240, (IA-HCV-240-C) cannot be directions during cold and 4.3.2.
-249, and full-stroke exercised in the open shutdowns.
IA HCV-240-C direction quarterly duringpower operation, as exercising of the check valve will cause HCV-240 to cycle.
This could cause large scale depressurization of the RCS and thermal shock of the presunzer spray noz2le. Check valve IA-HCV-240-C cannot be partial-stroke exercised for the same reason.
J18 Concentrated This valve serves to isolate Valve will be stroke-tinn! Exercising this valve bonc acid to concentrated boric acid from the in the open direction during quarterly is charging pump charging pump suction header, his cold shutdown. impractical.
suction isolation valve cannot be stroke-timed Therefore, the valve: quarterly during power operation alternate is in HCV-268 because domg so would allow accordance with concentrated boric acid solution to be OM-10. Para. 4.2.1.
injected mto the RCS. Boration of the primary system dunng normal power operation would cause reactivity transients and possibly result in a plant shutdown. This valve cannot be partial-stroked for the same reason.
26
t e
liesn Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's .
Justification !
t J19 Charging pump Rese valves provide an alternate Valve HCV-2988 will be J19 does not !
discharge to charging flow path into the HPSI stroke-tested both in the adeguately demonstrate HPSI isolation header and an alternate source for open and closed directions the impracticality of >
valves: long term core cooling. Bey cannot during cold shutdown. exercising these valves HCV 308 and be stroke-timed quarterly dunng HCV-308 will be see 2988 power operation because a charging stroke-tested in the open quarterly Appendix (A, Item 7).
pump is continuously operating direction only, during cold during power operation. Opening shutdown one of these vafves would expose the HPSI header to charging pressure at a time when this is not a desired charging flow . It is impractical to shut down charging flow to perform this test because of the thermal and flow transients that would result.
120 HPSI header This check valve functions to prevent This check valve will be Exercising this valve check valve: backflow of charging flow to the exercised full open and full open quarterly or SI-323 lower design pressure HPSI piping closed during refueling during cold shutdowns .
when the alternate charging flow path outages. is impractical. !
is active. The only flow path Therefore, the '
available is into the RCS and since alternate is in the HPSI pumps do not develop accordance with sufficient discharge pressure to OM 10, Para. 4.3.2.
overcome RCS operating pressure, this valve cannot be exercised quarterly during power operation.
This valve cannot be exercised during ,
i cold shutdowns because the RCS does not contam an adequate expansion volume and a low-temperature overpressurization of the RCS could result. Additionally, this valve cannot be part-stroke exercised during pump test or miniflow because the minimum flow lines branch off upstream of the check valve and no flow occurs through this valve.
121 CS header Valves HCV 344 and -345 serve as Valve HCV-344 shall be J21 does not isolation valves CS isolation. These valves cannot be stroke-timed in both the adequately demonstrate and instrument stroke-tested quarterly during power open and closed direction the impracticality of .
air accumulator operation since the potential for during cold shutdown. exercising these valves check valve: spraying down the containment is HCV 345 shall be see HCV 344, increased. These valves represent the stroke-timed in the open quarterly Appendix (A, item 7).
-345, and only boundary between the CS and direction during cold IA-HCV-344-C safety injection pump headers and the shutdown. The IA check CS nozzJes when manaal valves valve IA-HCV-344-C shall
- S1 177 and SI-178 are open. The be exercised in the closed :
valves cannot be part-stroked for the direction during cold same reason Valve IA HCV 344-C shutdown.
is the IA accumulator check valve for i process valve HCV-344, and functions to allow the valve to be L closed on loss of IA, if required.
This check valve cannot be exercised quarterly as required as this would stroke the process valve. HCV 344.
27
M Itan Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's Justification 122 Shutdown These valves cannot be quarterly These valves will be Exercising these valves cooling from stroke-timed closed dunng power stroke-timed in the close open quarterly is RCS isolation operation be=se they are direction during cold impractical. >
valves: interlocked closed to ensure the shutdown pnor to initiating herefore, the HCV-347 and integrity of the pressure boundary shutdown cooling ( < 300*F alternate is in
-348 between Class 2501 and Class 301 and < 250 psi) while the accordance with piping when the RCS pressure is steam generator is still OM-10, Para. 4.2.1.
> 250 psia, available for removing decay heat from the pnmary.
323 Si tank leakage These valves serve to isolate These valves will be Exercising these valves coolers inlet containment penetrations M-39 and stroke-timed in the close closed quarterly is and outlet M-53, component cooling s tem direction during cold impractical.
isolation valves: penetrations. They cannot shutdowns Therefore, the HCV-425A, stroke-timed closed quarterly during alternate is in
-4258, -425C, power operation because failure of accordance with and -425D these valves in the closed position OM-10, Para. 4.2.1.
would terminate cooling flow to safety injection tank leakage coolers.
This would have the potential for lifting the relief valve (SI-222) to the RCDT which could eventually cause reactor coolant to overflow to the containment floor, causing a ventilation isolation actuation signal.
These valves cannot be part-stroked because they are either fully opened or fully closed.
124 RCP cooler These valves serve to isolate Valves HCV-438A, -438B, Exercising these valves isolation valves containment penetrations M-18 and -43BC and -438D will be closed quarterly is and associated M-19, RCP seal cooling water. stroke-timed in both the impractical.
instrument air Exercising these valves would isolate open and close direction Therefore, the supply check cooling watei flow to the RCPs dunng cold shutdown, alternate is in valves: which could damage the pumps if provided the RCS is accordance with HCV-438 A, they are operating. RCP failure depressurized, RCS OM-10, Paras. 4.2.1
-4"$ 8 B , -43 8C, dunng power operation could result temperature is less than and 4.3.2.
-43 8 D. in a plant shutdown. Therefore, it is 130 F, and RCPs are IA-HCV-438B- not practical to exercise these valves secured. IA accumulator C and -438D-C quarterly during power operations. check valves Dunng some cold shutdowns, RCS IA-HCV-438B-C and temperature may be held above 130 *F -438D-C will be exercised and plant conditions may not allow closed during cold further cooldown or stopping all shutdown, provided the RCPs. Exercising these valves RCS is depressurized, RCS during cold shutdowns when RCS temperature is less than temperature is greater than 130'F or 130'F and the RCPs are .
when any RCP is running could secured.
result in RCP damage. Therefore, it is not practical to exercise these valves when those plant conditions exist. These valves cannot be part-stroked because they are either fully open or fully closed. The lA accumulator check valver. not be ,
exercised qu rterly durica awer operation as exercising thue valves will cause cycling of the process valves.
28
Itan Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's Justification J25 Nuclear nese valves serve to isolats Rese valves shall be Exercising these valves detector well containment penetrations M 15 and stroke-timed in the close closed quarterly is cooling units M-11, component cooling water direction during cold impractical.
cooling water (CCW) penetrations. These valves shutdown. Therefore, the isolation valves: cannot be stroke-timed questerly alternate is in IICV-467A, during power operation because accordance with
-467B, -467C, failure of these valves during testing OM-10, Para. 4.2.1.
and -467D would render the nuclear detector (See Appendix A, well cooling units inoperable. This item 8) would cause the nuclear instrumentation to have erratic indication. Should the nuclear detector well cooling units fail, the LCO specified in TS 2.13 would be entered and could result in a plant shutdown. These valves cannot be partial-stroked because they are either fully opened or fully closed.
126 Main steam These valves serve to isolate the main nese valves will be Exercising these valves isolation stop steam headers. Hey cannot be tested stroke-timed in the closed closed quarterly is check valves: quarterly during power operation direction during cold impractical.
liCV-1041 A because doing so would isolate steam shutdown. Therefore, the and -1042 A flow in the steam generators and alternate is in result in a turbine and reactor trip. accordance with These valves cannot be part-stroked OM-10. Para. 4.2.1, because they are either fully opened or fully closed.
J27 Main steam These valves serve to provide a These valves will be Exercising these valves isolation bypass pathway from the steam generators to stroke-timed in the closed open quarterly is valves: the steam dump and bypass valves in direction during cold impractical.
11CV-1041C the event that the main steam shutdown. Therefore, the and -1042C isolation valves (MSIV) close. alternate is in Stroke-timing these valves quarterly accordance with during power operation is not OM-10, Para. 4.2.1, acceptable because the valves are interlocked closed when the MSIVs are open. Bypassing this interlock could cause the MSIVs to close, causing the turbine to trip and resulting in a reactor trip. The valves cannot be part-stroked for the same reason.
J28 Main feedwater Valves HCV-1385 and -1386 cannot Rese valves will be Exercising these valves isolation valves: be stroke-timext quarterly during stroke-timed in the closed closed quarterly is HCV-1385 and power operation because doing so direction during cold impractical.
-1386 would isolate feedwater to steam shutdown. Therefore, the generators resulting in a reactor trip. alternate is in These valves cannot be part-stroked accordance with because they are either fully opened OM 10, Para. 4.2.1.
or fully closed.
J29 Steam generator These valves cannot be quarterly These valves will be Exercising these valves '
blowdown stroke-timed during power operation stroke-timed in the closed closed quarterly is isolation valves: because doing so would terminate the direction during cold impractical.
liCV-1387A, steam generatcr blowdown and shutdowns. Herefore, the
-1387B, disrupt all volatile chemistry control. alternate is in
-1388 A, and Rey cannot be partial-stroked accordance with
-1388B because they are either fully opened OM 10, Para. 4.2.1.
or fully closed. (See Appendix A, item 7) 29
Itern Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's Justification J30 Instrument air Rese valves serve to isolate IA These valves will be Exercising these valves CIVs: pressure to containment systems, stroke-timed in the closed closed quarterly and PCV-1849A PCV-1849A (inboard) and -1849B direction dunng cold during each cold and -1849B (outboard) were utded during the shutdown when the RCS shutdown is refuelmg and maintenance outage temperature is less than impractical.
(Fuel Cycle 12) in 1988. 130"F with RCPs off and Therefore, the Stroke-timing cannot be performed the RCS depressurized. alternate is in quarterly dunng power operations or accordance with cold shutdown with RCS temperature OM-10, Para. 4.2.1.
greater than 139'F and the RCS not depressurized. The valves cannot be part-stroked, because they are either fully opened or fully closed. Closing these valves could:
(1) cause fluctuations in the pressure control of the pressurizer .
(PCV-103-1, PCV-103-2),
(2) result in damage to RCP seals (HCV 241),
(3) disrupt RCS letdown to CVCS (TCV 202, LCV-101-1, LCV-101-2),
(4) damage the nuclear detector instrumentation (HCV-467 A/C),
(5) cause level fluctuation in the SIT (HCV-2916. HCV-2936, HCV-2955 HCV-2976), and (6) cause loss of steam generator blowdown (HCV-1387A and ,
HCV-1388A). j The ripple effect caused by the exercise stroking of PCV-1849A/B would be detrimental during power operation or when in cold shutdown with RCS temperature greater than 130*F and not depressurized.
J31 Steam generator These valves serve to isolate the These valves will be Exercising these valves blowdown steam generator blowdown sampling stroke-timed in the closed closed quarterly is sample isolation lines. These valves cannot be direction during cold impractical, valves: stroke-timed quarterly during power shutdown. Therefore, the HCV-2506A. opera
- ion because domg so would alternate is in
-2506B, terminate blowdown sample line accordance with 2507A, and flow. The steam generator blowdown OM-10 Para. 4.2.1.
-2507B activity monitor is on the sample line.
TS 2.9(l)e requires that blowdown activity shall be continuously monitored by the steam generator blowdown sample monitoring system when blowdown is occurring. Steam generator blowdown is a continuous function at the FCS. Part-stroking cannot be performed since these valves are either fully opened or fully closed.
30
Itan Valve Justification for Deferring Valve Proposed Alternate Evaluation of Number Identification Exercising Testing Licensee's Justification J32 HPSI alternate Valve HCV-2987 closes to provide a Valve HCV-2987 will be J32 does not header isolation long term core cooling flow path. It stroke-timed both in the adeguately demonstrate valve and its cannot be stroke-timed quarterly open and closed directions the impracticality of instrument air during power operation because during cold shutdowns. exercising these valves accumulator failure m a non-conservative position The lA accumulator check see check valve: would block one of the safety valve will be exercised in quarterly Appendix (A, Item C).
HCV 2987 and injecthn flow paths. This could the open and closed IA-HCV-2987 cause the plant to enter into an LCO directions during cold C and cause undue cycling of plant shutdown.
equipment. The IA accumulator check valve cannot be exercised quarterly durmg power operation as exercising of this check valve will cause cycling of the process valve.
133 Instrument air These are check valves on IA These check valves will be Exercising these valves i supp;f check accumulators attached to HCV-238 exercised in the open and quarterly is valvesi and -239, which are located inside closed directions at cold impractical.
I A-H CV-238-C containment. The process valves are shutdown. Therefore, the and -239-C remotely stroke-tested in both the alternate is in open and closed directions quarterly, accordance with but due to iriannsibility during OM-10, Para. 4.3.2.
power operation, the check valves are not able to be tested.
J34 Instrument air nese are check valven on IA These valves will be Exercising these valves supply check accumulators attached to HCV-385 full-stroke exercised in the quarterly is valves: and -386 (safety injection mini flow open and closed directions impract; cal.
l A-HCV-285-C bypass isolation valves). The process at cold shutdown. Therefore, the and -286-C valves are remotely stroke-tested alternate is in quarterly. The test methodology for accordace with the IA accumulator check valves OM-10. Para. 4.3.2.
requires the process velves to be closed greater than one hour each.
This isolates the SI miniflow recirculation line, which, if the SI pumps start, could cause these pumps to operate at shutoff head.
Therefore, the check valves are not able to be tested quarterly. Running the Si pumps at shutoff head could cause the pumps to overheat and cavitate. Prolonged closure of these valves could cause equipment damage.
1 31
l 4
l Itern Valve Justification for Defernng Vahe Proposed Alternate Evaluation of Numher Identification Exercising Testing Licensee's Justification 135 VCT outlet This check valve serves to prevent a Valve will be full-stroke It is impractical to check valve: divergent path from the boric acid exercised in the closed exercise this valve CH-166 injection system to the VCT. A direction during refueling quanerly, therefore, divergent path may reduce the outages. deferring exercising concentration of boric acid required until cold shutdowns is to be injected into the RCS. His in accordance with-check valve cannot be full-stroke OM 10, Pars. 4.3.2.
exercised in the closed direction However,135 does not quarter:y during power o ration er adeguately demonstrate cold shutdown. He o flow peak the impracticality of through this valve is to RCS, and exercising this valve would result in injecting highly when borating the RCS concentrated boric acid into the RCS. while going into cold injecting concentrated boric acid isso shutdowns (see the RCS during cold shutdown coedd Appendix A, item 7).
delay reactor startup because of the requirement to establish the proper boron concentration prior to reactor startup. He check valve cannot be partial-stroke exercised closed during wer operation or cold shutdowns For the same reasons.
J36 CS pump nese valves cannot be full-stroke Valves will be full-stroke Exercising these valves discharge check exercised open quarterly during exercised in the open quarterly or during valves: power operation because the only full direction during cold each cold shutdown is SI-135, -143, flow path is into the CS headers. shutdown when the CS impractical.
and -149 His would result in spraying dows pumps are able to be nerefore, the of the equipment in containment, aligned for shutdown alternate is in possibly causing equipment damage cooling to the shutdown accordance with and requiring extensive cleanup. OM-10, Para. 4.3.2.
Also, these valves cannot be cooling
( < 120 *F primaryheat exchangers part-stroke exercised dunng quartedy temperature) in accordance CS pump tests because the minimen with the FCS TS.
flow Imes branch off upstream of she check valves and therefore no flow occurs through these valves. Using the discharge tap downstream of the minimum flow Imes will overflow the floor drains in the auxiliary buil potentially creating an increase mdag radioactive contarm,ation and backFround radiation 'evels.
J37 Si and CS His valve serves to isolate CCW Valve HCV-474 shall be Exercising these valves pump bearing from the Si and CS pump beanng stroke-timed in the open quarterly as coolers CCW coolers. His valve cannot be direction during cold impractical.
isolation valve: quarterly stroke-timed during power shutdown. Herefore, the HCV-474 operation because failure of tlus valve alternate is in in a non<onservative position would accordance with render the S1 and CS pumps OM-10, Para. 4.2.1.
inoperable. Should the CCW to (See Appendix A, bearing coolers fail, the LCO in T5 Item 8) 2.01 would be entered and could result in a forced plant shutdown.
This valve cannot be partial stroked because it is either fully open or fully closed.
32
- . -. - - - .- - - -_. _ ~ . . - . . .. . . _ . .
N Iten Valve Justification for Deferring Valve Frg d Alternate Evaluation of Number Identification Exercising resting Licensee's Justification J38 These check These valves cannot be exercised Check valves will be full Exercising these valves valves are quarterly during power operation, as flow exercised in the closed quarterly is instrument air exercising these valves will cause direction during cold impractical. ,
supply header isolation of the control room (CR) air shutdown. Therefore, the check valves for filtration rs. Failure of the CR alternate is in ,
the control air filtration .rs in a non- accordance with -
room HVAC conservative position would cause the OM 10. Para. 4.3.2.
dampers: CR filtration system to be inoperable.
IA PCV This would require the plant to be in
-6680A- t -C, cold shutdown per TS 2.12. Failure
-6680A 2-C, of the dampers m the opevi ition
-6680B-1-C, would not allow the CR to i isolated
-6680B-2-C, during a toxic gas release. This and would result in entry into TS 2.01.
IA-PCV-6682-C I f
J39 Main steam These valves cancos be exercised Valves HCV-1041B and it is impractical to ;
stop check quarterly dunng power operation -1042B will he alternately verify closure of these !
(reverse flow) because doing so would cause steam disassembled and inspected valves quarterly or valves: to be isolated to the main steam one each refueling outage. during cold shutdowns.
HCV-1041B header, causing the turbine to trip Sample disassembly of these The proposed test and 1042B and resulting in a reactor trip. It is check valves is in method is in impractical to reverse flow test these accordance with O&M accordance with >
I valves during cold shutdown; to do so Part 10 and the NRC OM-10, Para. 4.3.2.4.
would require the downstream side of guidelines established in 'The alternase test the valves to have reverse flow Generic letter 89 04, frequency is approved ;
Attachment 1, Position 2.
~
sufficient to close the 600 pound,28 by GL 89-04 provided inch disks. To close these disks For an 18-month refueling that the testing would require extensive modifications cycle, this method of complies with all of ,
to the secondary side of the main sample disassembly and the provisions of steam system to permit sufficient DP mspection :nsures that each GL 89-04, {
to close the valve disks. Another check valve is disassembled Attachment 1, ;
method would he to fill the and in . ted at least once Position 2. !
downstream side of the valve disks every years. !
with fluid. To do this would require ;
extensive piping and support modifications because of excessive loading on the main steam piping.
To perform any type of successful reverse flow test on these check valves would require extensive plant modifications and manpower, and ,
would subject the main steam system to potentially detrimental conditions, ;
without providing a commensurate -
increase in public safety or check valve reliability. *
?
5 i
i 33 .
k . . . - - v - - m ..
APPENDIX A IST PROGRAM ANOMALIES A-1
APPENDIX A IST PROGRAM ANOMALIES Anomalies or inconsistencies found during the evaluation are given below. These anomalies )
summarize concerns with the IST program that require additional actions by the licensee for i resolution. The licensee should resolve these items as indicated.
I
- 1. The IST program does not include a description of how the components were selected and how testing requirements were identified for each component. The review performed for this Safety Evaluation (SE)/TER did not include verification that all pumps and valves within the scope of 10 CFR 50.55a and Section XI are contained in the IST program, and did not ensure that all applicable testing requirements have been identified. Therefore, :
the licensee is requested to include this information in the IST program. The program should describe the development process, such as a listing of the documents used, the method of determining the selection of components, the basis for the testing required, the basis for categorizing valves, and the method or process used for maintaining the program current with design modifications or other activities performed under 10 CFR 50.59.
- 2. Pump Request E3 requests relief from the flow rate acceptance criteria for the charging pumps and proposes to not have an Alert Range for these pumps and to set the Required Action Range at < 35 gpm and >40 gpm (refer to Section 2.2.1.1 of this report). The proposed Required Action Ranges do not differ significantly from the Code ranges, however, the proposed Acceptable and Alert Ranges are non-conservative in comparison with the Code requirements. The licensee'sjustification supporting this deviation from the Code is that there is no minimum flow rate mentioned in the USAR for the charging pumps. However, the criteria of Table 3 are not based on specified system operational requirements, they are based on an amount of pump degradation that causes concern about continued pump operational readiness. These limits should not be ignored unless it can be shown that they may not be indicative of pump degradation that could increase the likelihood of the pump not being capable of performing its safety function. Therefore, we recommend that relief be denied, j i
- 3. Valve relief requests El, E2, and E3 deal with sample disassembly of check valves (refer to Sections 3.2.1.1,3.2.2.1, and 3.3.1.1 of this report). OM-10 permits the use of disassembly of check valves to verify obturator movement as an alternative to exercising with flow or a mechanical exerciser. However, when using this method, OM-10 requires disassembly of each valve every refueling outage. GL 89-04, Position 2, permits the use of a sampling program for identical valves in similar applications. GL 89-04 also provides a mechanism for extending the valve disassembly interval in cases of extreme hardship. The licensee's basis supports extending the disassembly interval based on the low failure rate of these specific valves and similar valves in the nuclear industry.
However, the criteria for extending the interval in GL 89-04 requires the licensee to disassemble and inspect each valve in the group and to document in detail the valve condition and its capability of being full stroke exercised. The request indicated that each valve had been disassembled and found to be "like new." Stating that a valve is "like new" may be a subjective evaluation unless supported by a quantitative assessment such as A-2
i taking critical dimension measurements and comparing them with new valve baseline measurement data. The GL 89-04 interval extension criteria do not provide specific evaluation requirements (e.g., trending critical dimension measurements), however, the ,
licensee's evaluation should be adequate to provide reasonable assurance that degradation is not occurring in the group valves at a rate that could result in a valve becoming incapable of performing its function prior to the next examination. The GL 89-04 interval .
l extension criteria also require a review of the installation of each valve addressing the "EPRI Applications Guidelines for Check Valves in Nuclear Power Plants." It is not clear from the relief request that this review has been performed and that the installation of these valves is satisfactory from that respect.
Disassembly and inspection is permitted by OM-10 and reliefis granted to perform it on a i sampling basis by GL 89-04, therefore, these valves may be disassembled and inspected l every refueling outage on a sampling basis provided that it is performed in accordance j with all of the provisions of GL 89-04. In addition, the disassembly interval may be j extended if all of the interval extension criteria of GL 89-04, Position 2, are met.
Relief is not granted for the above relief request; for testing that deviates from that prescribed in GL 89-04, Position 2, unless the request specifically identifies otherwise.
Whether the licensee complies with the provisions of GL 89-04 is subject to NRC inspection. If the licensee intends to deviate from a GL 89-04 position other than indicated in the current relief request, a revised relief request must be submitted for review and approval prior to implementing the testing.
Some test method may be feasible to verify the full-stroke open capability of the affected valves in lieu of disassembly and inspection. The licensee should consider methods such as using non-intrusive techniques (e.g., acoustics, ultrasonics, magnetics, radiography, or thermography) to verify a full-stroke of these check valves. The licensee should perform their investigation and if a test method is found to be practicable, the IST requirements for these valves should be satisfied by testing instead of disassembly and inspection.
- 4. In valve relief requests E2 and E3 (refer to Sections 3.2.1.1 and 3.2.2.1 of this report),
the licensee states "the sample disassembly of these check valves is in accordance with the NRC guidelines established in Generic Ixtter 89-04, Attachment 1, Position 2 with the exception of partial-stroking." Position 2 states that "if possible, partial valve stroking quarterly or during cold shutdowns, or after reassembly must be performed." Not performing part-stroke exercising in accordance with Paras. 4.2.1.2(b) and (d) is acceptable if the licensee identifies the technical basis that makes this testing impractical.
However, the pan-stroke exercise after reassembly required by Position 2 is to demonstrate that valve disassembly and reassembly has been performed in a manner that has not rendered the valve incapable of performing its function. This testing is to meet the post maintenance testing requirements of Para. 3.4. Not performing post maintenance testing to verify proper reassembly of these valves following their disassembly and inspection is unacceptable. If a part-stroke exercise following reassembly is impractical, this should be identified in the program and an alternate proposed that offers reasonable assurance of the valve's operational readiness following the maintenance procedure. The A-3
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6 OM-10, Para. 3.4, must be met for the disassembly and inspection activity unless specific !
reliefis requested and approved. j i
- 5. Valve Request G1 requests relief from the scope of OM-1 for thermal relief valves on safety-related systems and proposes to control the testing of these valves under the preventive maintenance program (refer to Section 3.1.1.1 of this report). In the 1986 edition of Section XI, the Code committee increased the scope of the valves subject to IST to include those valves which protect certain Code-Class safety-related systems from overpressure. Thermal relief valves installed to protect portions of safety-related systems against overpressure may be included in this expanded scope. The relief valves that may be involved are those that meet the following criteria: a) they protect a portion of a safety-related system, b) the protected piping and/or component may be isolated during a plant operating mode where credit is taken for operation of the safety-related system, c) the protected section is subject to a mechanism that could overpressurize it when isolated, and d) the integrity of the protected section (e.g., the absence of a rupture or stuck open relief valve) is required for the system to meet its safety function. Because some of the thermal relief valves at Fort Calhoun Station may be included in the expanded scope as discussed above, we recommend that general relief not be granted as requested for all thermal relief valves. The licensee should justify exclusion of those thermal relief valves that do not protect portions of safety systems that may be isolated during a plant operating mode where credit is taken for operation of the safety-related system. Relief valves that potect paruons of safety-related systems that may be iso'ated during a plant operating mode where credit is taken for operation of the system should be included in the IST program and tested to the Code requirements.
- 6. Valve request E6 requests relief from the test frequency requirements of OM-1 for the auxiliary feedwater pump oil cooler relief valve and proposes to test this valve every third refueling outage (refer to Section 3.4.1.1 of this report). Valve FW-1525 is the only one of its type and manufacturer, therefore, it forms a one valve sample group. OM-1 requires a minimum of 20% of the valves of each type and manufacturer be tested within any 48 months. The current refueling outage frequency is 18 months, therefore, the minimum time between three refueling outages would be 54 months. The 54 month period is not significantly longer than the 48 month period, therefore, this extension may be acceptable depending on the failure and repair record of this valve.
Discussions with members of the Working Group on Safety and Relief Valves (OM-1) l indicate that the working group did not consider one valve groups when writing the Code.
It is the impression of the working group members contacted, that the working group's intent is to have this type of valve tested at least once every ten years. The working group will meet on June 20 and 21,1994, and will include this issue on their agenda. We recommend that the alternative be authorized pursuant to 10 CFR 50.55a(a)(3)(i) until the :
OM-1 Working Group clarifies this issue. After the working group has clarified their 1 position on this issue, the licensee should either modify or delete relief request E6. i l
- 7. Several of the Deferred Test Justifications do not adequately demonstrate the impracticality of testing the subject valves quarterly during power operation or during cold 1
shutdowns (if testing is deferred until refueling outages). OM-10, Paragraphs 4.2.1.2 and A-4 l
d l
l Paragraph 6.2(d), requires the owner to include the justifications for these deferrals in their test plans. These justifications should provide technical bases that show why testing more frequently is impracticable. These bases should explain the negative consequences ,
that may result if the valve is tested during power operation or during cold shutdowns (if j applicable). Examples of negative consequences of testing that adequately demonstrate impracticality are that the testing could cause equipment damage, represent a safety hazard to test personnel, or result in a significant power reduction or plant trip.
J19 is an example of where the justification does not identify a negative consequence that may make more frequent testing impracticable. The licensee states that testing would "...
expose the HPSI header to charging pressure at a time when this is not a desired charging flow path." The reader is left to determine if this could overpressurize the HPSI header, cause an operational problem, or result in some other negative consequence.
Other DTJs that do not provide adequate justifications for not testing at power operation and/or during cold shutdowns are listed below along with the frequency for which additional justification is needed. In some of these cases the reviewer can confidently postulate the negative consequences of performing testing during power operations and/or during cold shutdowns (as applicable). However, due to differences in plant design and operation, the reviewer should not have to make these assumptions, therefore, the pertinent information should be furnished by the licensee. This is not to suggest that the licensee should change the proposed testing frequency for we affected valves, although, upon further evaluation, the licensee may elect to change these frequencies as is justified.
These DTJs should be revised to adequately justify the deferral of valve testing.
J5 Cold Shutdowns J8 Cold Shutdowns J11 Quarterly and Cold Shutdowns J21 Quarterly J29 Quarterly J35 Cold Shutdowns
- 8. The Basis for Justification paragraphs in J25, J32, and J37 contain statements such as "...
failure of these valves during testing would render ... inoperable." The objective of testing is to verify the operational readiness of safety related components. Testing can reduce the availability of these components, however, any reduction in availability may be more than offset by the increase in reliability afforded by the testing. If a component is in a degraded state that could cause it to fait during testing, it may not be capable of performing its safety function. It is far better to detect this degraded condition during testing than to have the component fail when required to actuate to mitigate the consequences of an accident. These DTJs should be revised to adequately justify the deferral of valve testing or the valves should be tested at a more frequent Code interval.
- 9. The Alternate Testing paragraphs in 16 and J13 indicate that the subject valves will be tested during cold shutdowns. However, these paragraphs include further restrictions on when the listed valves can be tested (i.e., provided the feedwater system is able to be isolated from the steam generator and the feedwater lines are able to be drained).
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o i Because of these provisions, these valves cannot be tested during many cold shutdowns.
Therefore, these Cold Shutdown Justifications should be changed to Refueling Gotage Justifications and a more detailed justification demonstrating the impracticality of 1 testing these valves every cold shutdown should be included in the Basis for Justification.
- 10. J7 states "Since failure of diese valves to function in the reverse flow direction would not interfere with the plant's ability to shutdown or to mitigate the consequences of an accident, these check valves shall be full-stroke exercised only in the open direction."
Excessive back leakage of hot feedwater through similar valves at other facilities can render the associated AFW train inoperable due to vapor binding of the AFW pump or by exceeding the design temperature rating of system piping. In addition, the Working Group on Check Valves (OM-22) and the NRC have taken the position that a check valve exercise test should involve verifying a valve in both tl.e open and the closed positions. The licensee should respond to this concern.
I1. The Alternate Testing of Jll d :s not address valves SI-196, -199, -202, and -205.
What testing is performed on these valves? In addition, the Basis for Justification needs to be clarified and augmented. The first two sentences do not apply to valve CH-469, because flow can be established through it using the charging pumps.
Therefore, there is no justification for not exercising CH-469 during power operation.
The third sentence applies only to valves SI-196, -199, -202, and -205. The basis should be clarified to indicate that this sentence does not apply to valves SI-343 and CH-469. The last sentence applies only to valve SI-343. There does not appear to be a technical basis that demonstrates the impracticality of full-stroke exercising valves SI-196, -199, -202, and -205 during cold shutdowns. The licensee should respond to these concerns.
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