ML14174B068
| ML14174B068 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 07/09/1991 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML14174B069 | List: |
| References | |
| NUDOCS 9107190193 | |
| Download: ML14174B068 (75) | |
Text
N UNITED STATES NUCLEAR REGULATORY COMMISSION o,
WASHINGTON, D.C. 20555 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM AND REQUESTS FOR RELIEF H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 DOCKET NO. 50-261 INTRODUCTION The Code of Federal Regulations, 10 CFR 50.55a(g), requires that inservice testing (IST) of ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where specific written relief has been requested by the licensee and granted by the Commission pursuant to 10 CFR 50.55a(a)(3)(i),
(a)(3)(ii), or (g)(6)(i).
In requesting relief, the licensee must demonstrate that:
(1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance with certain requirements of the applicable Code edition and addenda is impractical for its facility.
The Code of Federal Regulations authorizes the Commission to grant relief from ASME Code requirements upon making the necessary findings. The NRC staff's findings with respect to granting or not granting the relief requested as part of the licensee's IST Program are contained in this Safety Evaluation (SE).
The IST program addressed in this SE covers the second ten-year inspection interval from March 7, 1981, to February 19, 1992. The licensee's program includes a pump and valve IST program and is described in a letter dated April 15, 1988.
The program is based on the requirements of Section XI of the ASME Code, 1977 Edition through the Summer 1978 Addenda.
EVALUATION The IST program and the requests for relief from the requirements of Section XI of the ASME Code have been reviewed by the staff with the assistance of its contractor, EG&G, Idaho, Inc., (EG&G).
In addition, EG&G and staff members met with licensee representatives on June 12, 1986, and November 10, 1987, in working sessions to discuss questions resulting from the review of previous submittals. The Technical Evaluation Report (TER) provided as Attachment 1 is EG&G's evaluation of the licensee's inservice testing program and relief requests. The staff has reviewed the TER and concurs with the evaluations and conclusions contained in the TER. A summary of the pump and valve relief
.request determinations is presented in Table 1. The granting of relief is based upon the fulfillment of any commitments made by the licensee in its basis for each relief request and the alternative proposed testing.
910719o193 910709 PDR ADOCK 05000261 P
-2 No relief requests were completely denied. One relief request was partially denied (TER Section 2.7.1), thirteen relief requests were granted with certain conditions (TER Sections 2.5.1, 2.3.1, 2.6.1, 2.7.1, 2.9.1, 2.10.1, 2.2.1, 3.2.1.1, 3.3.1.1, 3.3.1.2, 3.4.1.1, 3.3.1.4, and 3.8.1.1), and five relief requests were granted on an interim basis (TER Sections 2.4.1, 2.8.1, 3.4.1.2, 3.7.1.1, and 3.3.1.6). One relief request is identified as an open item pending completion of staff review (TER Section 3.1.1). The licensee should refer to the specific TER section for a detailed discussion of these cases.
These denials and conditions are listed in the TER Appendix B which also lists other IST program anomalies identified during the review.
The licensee should resolve all the items listed in Appendix B in accordance with the staff guidance therein. Items 3, 4, 12, 14, and 15 in Appendix B should be resolved within one year of receipt of this SE or the next refueling outage, whichever is longer. As necessary, program/procedural changes covered by the remaining items in Appendix B should be made within 6 months of receipt of this SE.
CONCLUSION Based on the review of the licensee's IST program relief requests, the staff concludes that the relief requests as evaluated and modified by this SE will provide reasonable assurance of the operational readiness of the pumps and valves to perform their safety related functions. The staff has determined U
that granting relief, pursuant to 10 CFR 50.55a(a)(3)(i), (a)(3)(ii) and (g)(6 )(i), is authorized by law and will not endanger life or property, or the common defense and security and is otherwise in the public interest. In making this determination the staff has considered the alternate testing being implemented, compliance resulting in a hardship without a compensating increase in safety, and the impracticality of performing the required testing considering the burden if the ASME Code requirements were imposed. The last column of Table 1 identifies the regulation under which the requested relief is granted.
During the review of the licensee's inservice testing program, the staff has identified certain misinterpretations or omissions of ASME Code.requirements.
These items are summarized in the TER Appendix B. The IST program relief requests for H. B. Robinson Unit 2 provided by a submittal dated April 15, 1988, are acceptable for implementation provided that the corrective actions described in Appendix B are taken in accordance with the schedule set forth above in the last paragraph of the evaluation section.
Principal Contributor: K. Dempsey Date:
July 9, 1991
ENCLOSURE 1 Page No.
1 03/02/91 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE 1
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Pump
2.1.1 IWP-3400(a)
All pumps.
Test pumps on a Relief granted.
5.2.1 Test pumps quarterly frequency. (a)(3)(ii) monthly.
Pump
2.1.2 IWP-3300
All pumps Waive bearing Relief granted.
5.2.2 Measure pump temperature (a)(3)(i) bearing measurement temperature requirements, annually.
analyze bearing condition with vibration measurements.
Pump
2.4.1 IWP-3100
Service water Measure discharge Interim relief 5.2.3 Measure pump pumps, pressure and granted.
inlet and A, B, C, D vibration quarterly, (a)(3)(ii) differential perform a "dead pressures.
head" discharge pressure test at refueling outages.
Pump
2.5.1 IWP-3100
Auxiliary Measure flow rate Provisional 5.2.4 Measure pump feedwater during cold relief granted.
flow rate
- pumps, shutdowns and (g)(6)(i) quarterly.
A, B refueling outages to accuracy allowed by existing plant instrumentation.
Pump
2.3.1 IWP-3100
Safety Measure flow rate Provisional 5.2.4 Measure pump injection during refueling relief granted.
flow rate
- pumps, outages to accuracy (g)(6)(i) quarterly.
A, B, C allowed by existing plant calibrated instrumentation.
Page No.
2 03/02/91 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE _
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Pump
2.6.1 IWP-3100
Residual heat Measure flow rate Provisional 5.2.4 Measure pump removal pumps, during cold relief granted.
flow rate A, B shutdowns and (g)(6)(i) quarterly.
refueling outages to accuracy allowed by existing plant instrumentation.
Pump
2.7.1 IWP-3100
Boric acid Compute flow rate at Provisional 5.2.4, Measure pump transfer cold shutdowns, relief granted flow rate
- PUMPS, for computing quarterly.
A, B flow rate.
(a)(3)(i)
Relief denied of testing interval 0r textension.
Pump
2.8.1 IWP-3100
Diesel fuel Compute flow rate Relief granted 5.2.5 Measure pump oil transfer and waive Code for differential
- pumps, accuracy and differential pressure.
A, B differential pressure IWP-4600 and pressure measurement measurement.
IWP-4100:
requirements.
(a)(3)(i)
Measure flow Interim relief rate granted for quarterly to flow rate required measurement.
accuracy.
(a)(3)(ii)
Pump
2.2.2 IWP-3500(a)
Auxiliary Measure lubricant Relief granted.
5.2.6 Measure pump feedwater level immediately, (a)(3)(i) lubricant
- pumps, prior to quarterly level after A, B, C pump testing.
five minutes Charging of pump
- pumps, operation.
A, B, C Residual heat removal pumps, A, 8 0II
Page No.
3 03/02/91 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE 1
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Pump
2.9.1 IWP-3100
Charging Measure pump flow Provisional 5.2.7 Measure pump pumps, rate at a reference relief granted.
differential A, B, C value of rotative (a)(3)(i) pressure.
speed.
Pump 2.10.1 IWP-3100:
Component Measure pump flow Provisional 5.2.8 Measure pump cooling water rate at refueling relief granted.
flow rate
- pumps, outages.
(g)(6)(i) quarterly.
A, B, C Pump
2.2.1 IWP-3100
Safety Calculate inlet Provisional 5.2.9 Direct injection pressure using relief granted.
measurement
- pumps, height of water in (a)(3)(ii) of pump inlet A, B, C vented suction pressure.
Containment source just.prior to spray pumps, pump testing.
A, B Boric acid
- pumps, A, B Residual heat removal pumps, A, B Service water
- pumps, A, B, C, 0 Pump
2.6.2 IWP-4120
Residual heat Impose +/- 1% full Relief granted.
5.2.10 Instrument removal pump, scale accuracy in (a)(3)(i) range three A, B lieu of +/- 2%
times allowed by Code.
reference value or less.
Page No.
4 3/02/91 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE 1
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Valve 3.1.1.1 IWV-3420:
All Perform 10 CFR 50, Open Item.
5.3.1 Biannual leak containment Appendix J, Type C, rate testing isolation leak rate testing in procedure.
valves.
lieu of Code required procedure.
Valve 3.2.1.1 IWV-3521:
Main steam Verify closure Provisional 5.3..
Exercise header check capability using relief granted.
quarterly.
- valves, disassembly and (g)(6)(i)
MS-261A, 2618, inspection on a 261C sampling basis at a refueling outage frequency.
alve 3.3.1.1 IWV-3521:
Safety Part-stroke exercise Provisional
.3.3 Exercise injection during cold relief granted.
quarterly.
accumulator shutdowns, (g)(6)(i) discharge disassemble and check valves, inspect on a SI-875D, 875E, sampling basis at a 875F refueling outage frequency.
Valve 3.3.1.2 IWV-3521:
Safety Full-stroke exercise Provisional 5.3.4 Exercise injection with flow during relief granted.
quarterly.
system cold refueling outages.
(g)(6)(i) leg injection check valves, SI-873A, 8738, 873C, 873D, 873E, 873F, 874A, 8748 Valve 3.4.1.1 IWV-3521:
Service water Part-stroke exercise Provisional 5.3.5 Exercise backup header quarterly, relief granted.
quarterly.
to auxiliary disassemble and (g)(6)(i) feedwater inspect every third check valve, refueling outage.
SW-544
Page No.
5 03/02/91 H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE 1
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Valve 3.4.1.2 IWV-3522:
Service water Full-stroke exercise Interim relief 5.3.6 Quarterly to steam these parallel check granted.
exercising driven valves together (a)(3)(ii) procedure auxiliary (collectively) requirements. feedwater pump quarterly.
oil cooler check valves, SW-542, 543 Valve 3.3.1.3 IWV-3521:
Safety Part-stroke exercise Relief granted.
5.3.7 Exercise injection pump quarterly, (g)(6)(i) quarterly.
discharge full-stroke exercise check valves, during refueling SI-879A, 879B, outages.
879C Valve 3.3.1.4 IWV-3521:
Containment Part-stroke exercise Provisional 5.3.8 Exercise spray pump during cold relief granted.
quarterly.
discharge shutdowns with air, (g)(6)(i) check valves, disassemble and SI-890A, 890B inspect on sampling basis during refueling outages.
Valve 3.5.1.1 IWV-3521:
Instrument air Verify closure Relief granted.
5.3.9 Exercise header capability by leak (g)(6)(i) quarterly.
containment rate testing at a isolation refueling outage
- valve, frequency.
IA-525 Valve 3.6.1.1 IWV-3521:
Refueling Part-stroke exercise Relief granted.
5.3.10 Exercise water storage quarterly, (g)(6)(i) quarterly.
tank to full-stroke exercise charging pump during refueling suction check outages.
- valve, CVC-357
Page No.
6 003/02/9 1 0
/
H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 SER TABLE 1
SUMMARY
OF RELIEF REQUESTS RELIEF TER SECTION XI EQUIPMENT ALTERNATE ACTION REQUEST SECTION REQUIREMENT IDENTIFICATION METHOD OF BY NUMBER
& SUBJECT TESTING USNRC Valve 3.3.1.5 IWV-3521:
Spray additive Bench test during Relief granted.
5.3.11 Exercise tank vacuum refueling outages.
(g)(6)(i) quarterly.
breaker
- valves, SI-8990, 899E Valve 3.7.1.1 IWV-3413(b):
Diesel fuel Verify valve Interim relief 5.3.12 Stroke timing oil day tank operability by granted.
requirements. isolation observing increasing (g)(6)(i)
- valves, fuel oil day tank FO-27A, 27B, level on biweekly 29A, 29B basis.
Valve 3.8.1.1 IWV-3413(b): Diesel engine Verify valve Provisional 5.3.12 Stroke timing air start operability by relief granted.
requirements. solenoid observing that (g)(6)(i)
- valves, diesels start during DA-19A, 198, monthly testing.
23A, 23B Valve 3.9.1.1 IWV-3416:
Main steam to Test valves within Relief granted.
5.3.13 Test valves steam driven one week after (g)(6)(i) within 30 auxiliary commencing power days prior to feedwater operation or prior return to check valves, to reaching cold operable MS-263A, 2638, shutdown.
status.
263C Valve 3.3.1.6 IWV-3521:
SI system cold Full-stroke exercise Interim relief 5.3.14 Exercise leg injection with flow during granted.
quarterly.
check valve, cold shutdowns and (a)(3)(ii)
SI-876A, 8768, refueling outages.
876C Combined RHR/SI/accumul ator cold leg injection check valves, SI-875A, 875B, 875C
EGG-NTA-8839 TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2 Docket No. 50-261 N. B. Stockton W. C. Hemming Published March 1991 Idaho National Engineering Laboratory EG&G Idaho, Inc.
Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DOE-ACO7-761D01570 FIN No. A6812 TAC No. 61653 0
CONTENTS ABSTRACT................------.
PREFACE................................
- 1. INTRODUCTION................................................. 1
- 2. PUMP TESTING PROGRAM.......................................... 3 2.1 General Relief Requests.................................. 3 2.1.1 Monthly Pump Testing..............................
3 2.2.1 Annual Bearing Temperature Measurements............ 4 2.2 Multiple System......................................... 5 2.2.1 Direct Measurement of Pump Inlet Pressure..........
5 2.2.2 Observation of Lubricant Level or Pressure.........
7 2.3 Safety Injection Pumps................................... 8 2.3.1 Flow Rate Measurement............................. 8 2.4 Service Water Pumps...................................... 10 2.4.1 Flow and Differential Pressure M easurement........... 10 2.5 Auxiliary Feedwater Pumps................................. 12 2.5.1 Flow Rate Measurement.............................. 12 2.6 Residual Heat Removal Pumps................................ 14 2.6.1 Flow Rate Measurement.............................. 14 2.6.2 Instrument Range Requirements...................... 16 2.7 Boric Acid Transfer Pumps................................. 17 2.7.1 Flow Rate Measurement.............................. 17 2.8 Diesel Fuel Oil Transfer Pumps................. !........... 19 2.8.1 Flow Rate Measurement.............................. 19 2.9 Charging Pumps........................................... 21 2.9.1 Differential Pressure Measurement................... 21 2.10 Component Cooling Water Pumps.............................
22 2.10.1 Flow Rate Measurement............................. 22 Re id al He t em va P mp 1
3.'
VALVE TESTING PROGRAM........................................ 25 3.1 General Relief Requests................................. 25 3.1.1 Leak Rate Testing of Containment Isolation Valves..
25 3.2 Main Steam System...
................................. 26 3.2.1 Category C Valves................................ 26 3.3 Safety Injection System................................. 28 3.3.1 Category C Valves................................ 28 3.4 Service Water System.................................... 38 3.4.1 Category C Valves................................ 38 3.5 Instrument Air System................................... 42 3.5.1 Category A/C Valves.............................. 42 3.6 Chemical And Volume Control System........................ 43 3.6.1 Category C Valves................................ 43 3.7 Diesel Generator Fuel Oil System...........................
44 3.7.1 Category B Valves..................................
44 3.8 Diesel Generator Air Start System..........................
46 3.8.1 Category 8 Valves................................ 46 3.9 Auxiliary Feedwater System (Steam Supply).................. 48 3.9.1 Category C Valves................................ 48 APPENDIX A--P&ID LIST
............................................ A-1 APPENDIX B--IST PROGRAM ANOMALIES IDENTIFIED DURING THE REVIEW........
B-1 iv
TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT 2
- 1. INTRODUCTION Contained herein is a technical evaluation of the pump and valve Inservice Testing (IST) program submitted by Carolina Power and Light Company for its H. B. Robinson Steam Electric Plant, Unit 2.
By a letter dated May 2, 1986, Carolina Power and Light Company submitted a revision to the second ten year interval IST program for H. B.
Robinson, Unit 2. Working meetings with Carolina Power and Light Company, NRC and EG&G Idaho, Inc. representatives were conducted June 12, 1986 and November 10, 1987. The licensee's revised IST Program, dated April 15, 1988, was reviewed to verify compliance of proposed tests of pumps and valves whose function is safety related with the requirements of the ASME Boiler and Pressure Vessel Code (the Code),Section XI, 1977 Edition through Summer 1978 Addenda. Any IST program revisions subsequent to those noted above are not addressed in this technical evaluation report (TER). Any program revisions should follow the guidance of Generic Letter No. 89-04, "Guidance on Developing Acceptable Inservice Testing Programs."
In their IST program, Carolina Power and Light Company requested relief from the ASME Code testing requirements for specific pumps and valves.
These requests have been evaluated individually to determine if the criteria in 10 CFR 50.55a for granting relief has indeed been met. This review was performed utilizing the acceptance criteria of the Standard Review Plan, Section 3.9.6, the Draft Regulatory Guide and Value/Impact Statement titled, "Identification of Valves for Inclusion in Inservice Testing Programs," and Generic Letter No. 89-04, "Guidance on Developing Acceptable Inservice Testing Programs."
The IST Program testing requirements apply only to component testing (i.e., pumps and valves) and are not intended to provide the basis to change the licensee's current Technical Specifications for system test requirements.
1
Section 2 the Carolina Power and Light Company bases for requesting relief from the Section XI requirements for the H. B. Robinson Steam Electric Plant pump testing program, and the EG&G reviewer's evaluations and conclusions regarding these requests. Similar information is presented in Section 3 for the valve testing program.
A listing of P&IDs and Figures used for this review is contained in Appendix A.
Inconsistencies and omissions in the licensee's IST program noted during the course of this review are listed in Appendix B. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
2
- 2. PUMP TESTING PROGRAM The IST program submitted by the Carolina Power and Light Company for the H. B. Robinson Steam Electric Plant, Unit 2, was examined to verify that all pumps that are included in the program are subjected to the periodic tests required by the ASME Code,Section XI, 1977 Edition through the Summer 1978 Addenda and the NRC regulations, positions, and guidelines. The reviewers found that, except as noted in Appendix B or where specific relief from testing has been requested, these pumps are tested to the Code requirements and the NRC regulations, positions, and guidelines. Each Carolina Power and Light Company basis for requesting relief from the pump testing requirements and the reviewer's evaluation of that request are summarized below and grouped according to system.
2.1 General Relief Reauests 2.1.1 Monthly Pump Testing 2.1.1.1 Relief Request. The licensee has requested relief from the monthly pump testing requirements of Section XI, IWP-3400(a), for of all pumps in the IST program. The licensee has proposed testing all pumps at a quarterly frequency, or in accordance with any specific relief requests granted by the NRC.
2.1.1.1.1 Licensee's Basis For Requesting Relief--Monthly Section XI operability testing has been a plant requirement for most of these pumps since operation began. An analysis of the results of these tests and comparable data from other operating plants has shown no significant changes in performance. Based on this analysis, the continuation of Section XI monthly testing would not significantly increase plant safety.
Monthly pump testing requires a total of at least 250 hours0.00289 days <br />0.0694 hours <br />4.133598e-4 weeks <br />9.5125e-5 months <br /> per year of pump operation, at least 575 man-hours per year for data acquisition, and at least 50 man-hours per year for data reduction, analysis, and record keeping. This amounts to a total of 625 man-hours per year. At a conservative total costs of $20 per man-hour, this amounts to $12,500 per year. Based upon the average exposure rates in the pump access areas, the 3
total man-rem exposure per year for pump testing is approximately 1.0 man-rem. At the present conservatively estimated cost of $10,000 per man-rem to plant personnel, this exposure costs an additional $10,000 per year. Total cost is approximately $22,500 per year, for no measurable increase in safety.
These pumps will be tested in compliance with ASME Section XI, 1977 Edition through Summer 1978 addenda, and this program once per quarter.
This is in agreement with changes that were implemented in Subsection IWP of the Code in the Winter 1979 addenda.
2.1.1.1.2 Evaluation--The edition of the Code utilized by the licensee for their IST program requires monthly pump testing. Later editions of the Code allow quarterly pump testing to fulfill IST program requirements. Monthly pump testing results in significantly greater costs and radiation exposures. However, industry and NRC experience has shown that monthly pump testing does not yield a significant increase in quality or safety. As such, quarterly pump testing would provide reasonable assurance of operational readiness for the pumps in the IST program.
Based on the determination that the licensee's proposed alternative would provide reasonable assurance of operational readiness, and that compliance with the Code pump testing frequency requirement would result in hardship or unusual difficulty without a compensating increase in the level of quality or safety, relief may be granted as requested.
2.1.2 Annual Bearing TemDerature Measurements 2.1.2.1 Relief Reauest.
The licensee has requested relief from the annual pump bearing temperature measurement requirements of Section XI, Paragraph IWP-3300, for all pumps in the IST program. The licensee has proposed measuring pump vibration quarterly per IWV-4500.
2.1.2.1.1 Licensee's Basis For Reauestina Relief--The referenced Edition of the Code requires bearing temperature to be recorded annually.
The detection of possible bearing failure by a yearly temperature 4
measurement is highly unlikely. It requires at least an hour of pump operation to achieve stable bearing temperatures. The small probability of detection of bearing failure by temperature measurement does not justify the additional pump operating time required to obtain the measurements. The vibration measurement performed during quarterly intervals will provide better indication of impending bearing failure than an annual bearing temperature measurement. A review of historical bearing temperature data collected bears this out. Vibration measurements will be performed at quarterly intervals per IWP-4500.
2.1.2.1.2 Evaluation--Bearing temperature measurements, for pumps without installed bearing temperature measurement instrumentation, must be taken at or near the bearing housing. Although the measured temperatures will usually be greater than ambient temperature, they are more a function of environmental conditions than actual bearing temperature. Further, the itemperature at the bearing housing would not increase significantly until immediately before a bearing failure. Therefore, the likelihood of detecting an impending bearing failure with a single annual bearing temperature measurement is very small.
The additional run time required to make this measurement on standby pumps is burdensome for the licensee, and does not significantly improve the ability to detect pump mechanical degradation. The use of pump vibration measurements provides more information about pump mechanical condition than could be obtained by measuring the temperature of the bearing housing. Therefore, the licensee's proposal, to use vibration measurements to analyze pump bearing condition, would provide an acceptable level of quality and safety.
Based on the determination that the proposed alternative would provide an acceptable level of quality and safety, relief may be granted as requested.
2.2 Multiple Systems 2.2.1 Direct Measurement of Pump Inlet Pressure 2.2.1.1 Relief Reauest.
The licensee has requested relief from the direct pump inlet pressure measurement requirements of Section XI, Paragraph 5
IWP-3100, for the following pumps. The licensee has proposed calculating the inlet pressure by measuring the height of water in the vented suction source just prior to the pump test.
Containment spray pumps CS-A, 8 Safety injection pumps SI-A, 8, C Residual heat removal pumps RHR-A, 8 Service water pumps SW-A, B, C, D Boric acid transfer pumps A, 8 2.2.1.1.1 Licensee's Basis For Reauesting Relief--There are no installed suction gauges on the pumps. These pumps take a suction from vented static head reservoirs during testing. Suction pressure is calculated from this reservoir level.
Flow from the pumps is routed through closed systems back to the suction source. Suction pressure differences prior to and during pump operation are negligible. Static head/reservoir level will be determined immediately prior to pump operation and not during. No alternate testing is required since suction pressure values do not change during testing.
2.2.1.1.2 Evaluation--These pumps are not equipped with suction pressure instrumentation, therefore, direct suction pressure measurements cannot be taken either prior to pump start or during operation. System modifications would be.required to enable direct measurement of suction pressure. These modifications would be a hardship for the licensee due to the costs involved.
During testing, these pumps take suction from reservoirs that are vented to atmosphere, therefore, the pressure at the pump suction is determined by the height of liquid above the pump suction. The primary purpose of the pump suction pressure measurement is to ensure the required net positive suction head for the pumps is available and to ensure consistent initial test conditions. Maintaining a minimum level in the suction reservoir would provide assurance that the required suction head is available. Blockage in the pump suction piping would be indicated by pump cavitation and a reduction in pump discharge pressure and flow rate. Calculation of pump suction pressure should be adequate to monitor pump condition and detect degradation and as such, would provide reasonable assurance of operational readiness 6
provided the suction pressure calculation methods meet the accuracy requirements of the Code.
Based on the determination that requiring the installation of suction pressure instrumentation would result in hardship without a compensating increase in the level of quality or safety, relief may be granted provided the licensee's suction pressure calculation methods are within the accuracy that would result from using instruments meeting the Code accuracy requirements.
2.2.2 Observation of Lubricant Level or Pressure 2.2.2.1 Relief Request. The licensee has requested relief from the requirement of Section XI, Paragraph IWP-3500(a), to observe lubricant level after five minutes of pump operation, for the following pumps. The licensee has proposed observing the lubricant level immediately prior to quarterly pump testing.
Auxiliary feedwater pumps AFW-A, 8, C Charging pumps CVC-A, 8, C Residual heat removal pumps RHR-A, 8 2.2.2.1.1 Licensee's Basis For Reauesting Relief--Oil levels in these pumps fluctuate during operation. Therefore, oil levels cannot be verified during operation since pump operation affects the oil levels. Oil levels will be verified as adequate prior to pump operation at quarterly intervals, as a minimum.
2.2.2.1.2 Evaluation--Oil levels fluctuate during pump operation, therefore, lubricant level observed during pump operation would, not be indicative of the actual level.
Observing oil levels just prior to pump operation would indicate whether the oil inventory is sufficient for proper operation of these pumps and would, therefore, provide an acceptable level of quality and safety.
Based on the determination that the licensee's proposed alternative would provide an acceptable level of quality and safety, relief may be granted as requested.
7
2.3 Safety Inlection Pumos 2.3.1 Flow Rate Measurement 2.3.1.1 Relief Request. The licensee has requested relief from the quarterly flow rate measurement requirements of Section XI, Paragraph IWP-3100, for the safety injection pumps SI-A, B, and C. The licensee has proposed measuring flow at a refueling outage frequency to the accuracy allowed by existing plant calibrated instrumentation.
2.3.1.1.1 Licensee's Basis For Reauestina Relief--The H. B.
Robinson Unit 2 construction permit was issued prior to January 1, 1981.
Therefore, from 10CFR5O.55a(g)a, the following applies:
"...components (including supports) shall meet the requirements of paragraphs (g)(4) and (5) of this section to the extent practical.."
Paragraph (g)(4) of 10CFR50.55(a) requires that code class components meet the requirements of later code editions that become effective with the exception of the design and access provisions. It further states that these requirements shall be met to the extent practical within the limitations of design, geometry and materials of construction of the components.
Paragraph (g)(5) allows licensees to request relief from the requirements determined to be impractical. The Robinson Plant design did not incorporate the flow instrumentation necessary to meet Section XI 1977 Edition, Summer 1978 Addenda requirements under all operating modes. Flow measurement must be conducted under specific modes of operation or by placing the equipment in a configuration that prevents it's normal function, thus placing the unit in a Limiting Condition for Operation. Therefore, alternate testing is requested for selected equipment.
Pump operating assessments will be made quarterly using differential pressure measurements. In addition, flow, differential pressure and vibration will be measured at refueling intervals when the reactor head is removed for filling the refueling cavity. Flow measurement quarterly during normal operation is impractical due to the shutoff head of the pumps (1500 psig) being below reactor coolant system (RCS) pressure (2235 psig).
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Injecting water into the RCS at cold shutdown is impractical due to the potential for low temperature overpressurization of RCS components.
Therefore, the refueling test constitutes the only practical interval for performing this test. (Note that where flow is measured it will be to the accuracy allowed by existing plant calibrated instrumentation.)
2.3.1.1.2 Evaluation--The recirculation line used for quarterly testing of these pumps is not instrumented. The only instrumented flow path available for testing these pumps is into the reactor coolant system. This flow path cannot be used quarterly during power operation because the shutoff head of the safety injection pumps is below normal reactor coolant system pressure. Testing the safety injection pumps during cold shutdowns using this flow path could result in a low temperature overpressurization of the reactor coolant system. Use of the instrumented flow path is practicable only during refueling outages when the reactor vessel head is removed.
Measurement of pump flow rate during quarterly testing could only be accomplished after significant system modifications, which would be burdensome for the licensee due to the cost involved.
In cases where flow can only be established through a non-instrumented path quarterly and a path exists at cold shutdowns or refueling outages to perform pump testing under full or substantial flow conditions, the staff has determined that the increased interval is an acceptable alternative to the Code requirements provided that pump differential pressure, flow rate, and bearing vibration measurements are taken and analyzed during this testing and that quarterly testing measuring at least pump differential pressure and vibration is continued. This staff position is outlined in Generic Letter No. 89-04, Attachment 1, Item 9.
The licensee has stated that flow rate measurements will be to the accuracy allowed by existing plant calibrated instrumentation. If instrumentation used for pump testing does not meet the accuracy requirements of Section XI, IWP-4100, the licensee must request specific relief from the Code requirements. To obtain relief, the licensee's relief request should indicate the specific plant instrumentation that does not meet the accuracy 9
requirements of IWP-4100, the actual accuracy of the instrumentation, and should show that these instruments will yield indications sufficiently accurate to monitor pump condition and detect degradation.
Based on the determination that compliance with the Code requirements is impractical, that the measurement of pump flow rate during refueling outages would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief from the Code flow rate measurement frequency requirement may be granted provided the licensee conforms to the staff position of Generic Letter No. 89-04,, Item 9.
2.4 Service Water Pumos 2.4.1 Flow Rate and Differential Pressure Measurement 2.4.1.1 Relief Reauest.
The licensee has requested relief from the flow and differential pressure measurement requirements of Section XI, Table IWP-3100-1, for the service water pumps SW-A, B, C and D. The licensee has proposed measuring discharge pressure and vibration quarterly and performing a "dead head" discharge pressure test at refueling outages.
2.4.1.1.1 Licensee's Basis For Reauesting Relief--The service water pumps are used for removing heat from certain secondary system components during normal operation. Since heat load varies and inlet temperatures vary, automatic temperature control valves will vary the flow rates through the individual components, thus varying pump resistance. The system has no installed flow measuring devices capable of measuring flow from the pumps. The piping is concrete lined which prohibits the use of ultrasonic flow measuring techniques. There is insufficient room on the outlet piping of each individual pump to allow installation of any accurate flow devices.
The effect of each pump on Service Water System pressure is assessed quarterly. This is done by determining system pressure with three pumps running, then with four pumps running. The fourth pump contribution to the 10
header pressure can then be evaluated. This practice is repeated for each pump. Vibration is also checked on each pump on a quarterly basis.
In addition, H. B. Robinson assesses Service Water Pump operation during refueling by conducting a "dead head" (zero flow) test on each pump. This test provides a point for comparison to determine the condition of the pumps since the previous tests. These tests are used to supplement the quarterly Section XI test. If a pump is declared inoperable and maintenance performed, the pump is tested using the "dead head" test to reestablish the base line.
Performing a "dead head" test quarterly would place the Service Water System in a Technical Specification limiting condition for operation. This is considered unnecessary challenge to this system. Additionally, performing a "dead head" test on a multistage pump increases the potential for equipment damage. Therefore, it is desirable to keep such tests at a minimum.
An assessment of pump operation will be performed during refueling by conducting "dead head" (zero flow) tests on each pump.
2.4.1.1.2 Evaluation--These pumps are equipped with discharge pressure gages. In a separate relief request, the licensee proposed computing the suction pressure for these pumps based on the height of water above the pump inlet. The licensee has proposed determining each pump's contribution to total system pressure when it is started in parallel with three running pumps. However, this method of testing will not yield definitive values of discharge or differential pressure to which.the acceptance criteria of Table IWP-3100-1 may be applied for evaluation of the hydraulic condition of the pumps.
The licensee's proposal to determine each pump's contribution to total system pressure when it is started in parallel with the running pumps combined with performance of a "dead head" pressure test during refueling outages is not adequate to fully access the hydraulic condition of these pumps. The licensee should further investigate methods of determining differential pressure and flow rates or the development of some other quantitative method of evaluating hydrualic performance for these pumps.
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An interim period is necessary to give the licensee time to complete their investigation, the test procedures, and any necessary system design changes.
Imposition of immediate compliance would cause an extended outage which would result in hardship for the licensee without a compensating increase in safety. While the current testing is not adequate to fully access the hydraulic condition or degradation of these pumps, it does demonstrate that the pumps are operable and should provide reasonable assurance of operational readiness in the interim. Therefore, interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives.
2.5 Auxiliary Feedwater Pumps 2.5.1 Flow Rate Measurement 2.5.1.1 Relief Request. The licensee has requested relief from the quarterly flow rate measurement requirements of Section XI, IWP-3100, for the auxiliary feedwater pumps AFW-A, B, and SD. The licensee has proposed measuring flow at cold shutdown frequency to the accuracy allowed by existing plant calibrated instrumentation.
2.5.1.1.1 Licensee's Basis For Requesting Relief--The H. B.
Robinson Unit 2 construction permit was issued prior to January 1, 1981.
Therefore, from 10CFR50.55a(g)a, the following applies:
S...components (including supports) shall meet the requirements-of paragraphs (g)(4) and (5) of this section to the extent practical.."
Paragraph (g)(4) of 10CFR50.55(a) requires that code class components meet the requirements of later code editions that become effective with the exception of the design and access provisions. It further states that these requirements shall be met to the extent practical within the limitations of design, geometry and materials of construction of the components. Paragraph (g)(5) allows licensees to request relief from the requirements determined to be impractical.
The Robinson Plant design did not incorporate the flow 12
instrumentation necessary to meet Section XI 1977 Edition, Summer 1978 Addenda requirements under all operating modes. Flow measurement must be conducted under specific modes of operation or by placing the equipment in a configuration that prevents it's normal function, thus placing the unit in a Limiting Condition for Operation. Therefore, alternate testing is requested for selected equipment.
Pump operating assessments will be made quarterly using differential pressure measurements. In addition, flow, differential pressure and vibration will be measured at cold shutdown. Quarterly flow measurement would require feeding the steam generators at power. This is undesirable due to the unnecessary thermal shocking of the feedwater nozzles and feed rings Therefore, cold shutdown testing constitutes the only practical interval that this test can be performed. (Note that where flow is measured it will be to the accuracy allowed by existing plant calibrated instrumentation.)
2.5.1.1.2 Evaluation--The recirculation line used for quarterly testing of these pumps is not instrumented. The auxiliary feedwater header to the steam generators is equipped with flow instrumentation. However, pump testing quarterly during power operation using this flow path requires injecting cold auxiliary feedwater into the steam generators which would cause thermal shock to the feedwater injection nozzles and feed rings which could lead to their premature failure.
Measurement of pump flow rate during quarterly testing could only be accomplished after significant system modifications, which would be burdensome for the licensee due to the cost involved.
In cases where flow can only be established through a non-instrumented path quarterly and a path exists at cold shutdowns to perform pump testing under full or substantial flow conditions, the staff has determined that the increased interval is an acceptable alternative to the Code requirements provided that pump differential pressure, flow rate, and bearing vibration measurements are taken and analyzed during this testing and that quarterly testing measuring at least pump differential pressure and vibration is continued. This staff position is outlined in Generic Letter No. 89-04,, Item 9.
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The licensee has stated that flow rate measurements will be to the accuracy allowed by existing plant calibrated instrumentation. If instrumentation used for pump testing does not meet the accuracy requirements of Section XI9 IWP-4100, the licensee must request specific relief from the Code requirements. To obtain relief, the licensee's relief request should indicate the specific plant instrumentation that does not meet the accuracy requirements of IWP-4100, the actual accuracy of the instrumentation, and should show that these instruments will yield indications sufficiently accurate to monitor pump condition and detect degradation.
Based on the determination that compliance with the Code requirements is impractical, that measurement of pump flow rate during cold shutdowns and refueling outages would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief from the Code flow rate measurement frequency requirements may be granted provided the licensee conforms to the staff position of Generic Letter No. 89-04, Attachment 1, Item 9.
2.6 Residual Heat Removal Pumps 2.6.1 Flow Rate Measurement 2.6.1.1 Relief Reauest. The licensee has requested relief from the quarterly flow rate measurement requirements of Section XI, Paragraph IWP-3100, for the residual heat removal pumps RHR-A and B. The licensee has proposed measuring flow rate at a cold shutdown frequency to the accuracy allowed by existing plant calibrated instrumentation.
2.6.1.1.1 Licensee's Basis For Reauestina Relief--The H. B.
Robinson Unit 2 construction permit was issued prior to January 1, 1981.
Therefore, from 10CFR50.55a(g)a, the following applies:
"...components (including supports) shall meet the requirements of paragraphs (g)(4) and (5) of this section to the extent practical.."
Paragraph (g)(4) of 10CFR50.55(a) requires that code class components meet the requirements of later code editions that become effective with the 14
exception of the design and access provisions. It further states that -these requirements shall be met to the extent practical within the limitations of design, geometry and materials of construction of the components. Paragraph (g)(5) allows licensees to request relief from the requirements determined to be impractical.
The Robinson Plant design did not incorporate the flow instrumentation necessary to meet Section XI 1977 Edition, Summer 1978 Addenda requirements under all operating modes. Flow measurement must be conducted under specific modes of operation or by placing the equipment in a configuration that prevents it's normal function, thus placing the unit in a Limiting Condition for Operation. Therefore, alternate testing is requested for selected equipment.
Pump operating assessments will be made quarterly using differential pressure measurements. In addition, flow, differential pressure and vibration will be measured at cold shutdown. Instrumentation is not installed that would allow accurate quarterly flow measurement. Therefore cold shutdown is the only practical interval for performing this test.
(Note that where flow is measured it will be to the accuracy allowed by existing plant calibrated instrumentation.)
2.6.1.1.2 Evaluation--The recirculation line used for quarterly testing of these pumps is not instrumented. The only available instrumented flow path for testing these pumps is into the reactor coolant system. This flow path cannot be used quarterly during power operation because the shutoff head of the residual heat removal pumps is below normal reactor coolant system pressure. Use of the instrumented flow path is practicable only during cold shutdowns.
Measurement of pump flow rate during quarterly testing could only be accomplished after significant system modifications, which would be burdensome for the licensee due to the cost involved.
In cases where flow can only be established through a non-instrumented path quarterly and a path exists at cold shutdowns to perform pump testing under full or substantial flow conditions, the staff has determined that the O increased interval is an acceptable alternative to the Code requirements 15
provided that pump differential pressure, flow rate, and bearing vibration measurements are taken and analyzed during this testing and that quarterly testing measuring at least pump differential pressure and vibration is continued. This staff position is outlined in Generic Letter No. 89-04,, Item 9.
The licensee has stated that flow rate measurements will be to the accuracy allowed by existing plant calibrated instrumentation. If instrumentation used for pump testing does not meet the accuracy requirements of Section XI, IWP-4100, the licensee must request specific relief from the Code requirements. To obtain relief, the licensee's relief request should indicate the specific plant instrumentation that does not meet the accuracy requirements of IWP-4100, the actual accuracy of the instrumentation, and should show that these instruments will yield indications sufficiently accurate to monitor pump condition and detect degradation.
Based on the determination that compliance with the Code requirements is impractical, that measurement of pump flow rate during cold shutdowns and refueling outages would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief from the Code flow rate measurement frequency requirements *may be granted provided the licensee conforms to the staff position of Generic Letter No. 89-04, Attachment 1, Item 9.
2.6.2 Instrument Range Requirements 2.6.2.1 Relief Reauest.
The licensee has requested relief from the instrument range requirements of Section XI, Paragraph IWP-4120, for the residual heat removal pump discharge pressure gauges (PI-600 and PI-601).
The licensee has proposed imposing a full scale accuracy of +/-1% for these 0-600 psi instruments in lieu of the +/-2% full scale that the Code allows.
2.6.2.1.1 Licensee's Basis For Reauestina Relief--Applying the range criteria contained in IWP-4120 would result in requiring the subject gauges to have a full scale value of no more than approximately 420 psi.
The installed gauges have a range of 0-600 psi due to the need to operate the 16
residual heat removal system at pressures greater than 420 psi. A 0-600 psi range is also necessary due to the 600 psi relief setpoint of valve RHR-706.
A lower gauge range would result in possible overranging and equipment damage. Therefore, the installed 0-600 psi range gauge will be used in these locations.
Applying +/-2% full scale accuracy requirement of IWP-4110 would result in a calibration tolerance of approximately +/-8 psi for a 0-420 psi gauge. A more conservative requirement of +/-1% full scale accuracy will be applied to the 0-600 psi range gauges PI-600 and PI-601. This will result in a calibration tolerance of +/-6 psi.
This tolerance is more conservative than the Section XI requirement for a 0-420 psi range gauge.
2.6.2.1.2 Evaluation--Because the maximum operating pressure of the residual heat removal system can be as high as 600 psi, use of a 0-420 psi gauge satisfying the Code range requirements in this system could result in instrument damage. Allowing the use of gages with a +/-1% full scale accuracy and a range of 0-600 psig would provide an increased (more conservative) total measurement accuracy than that which would be obtained with a 0-420 psig pressure gage having a full scale accuracy of +/-2%. The licensee's proposed alternative should be sufficient to ensure that the test data is meaningful and would, therefore, provide an acceptable level of quality and safety.
Based on the determination that the proposed alternative would provide an acceptable level of quality and safety, relief may be granted as requested.
2.7 Boric Acid Transfer Pumps 2.7.1 Flow Rate Measurement 2.7.1.1 Relief Reaues-t.
The licensee has requested relief from the quarterly flow rate measurement requirements of Section XI, Paragraph IWP-3100, for the boric acid transfer pumps A and B. The licensee has proposed computing flow rate at a cold shutdown frequency.
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2.7.1.1.1 Licensee's Basis For Reauestina Relief--The H. B.
Robinson Unit 2 construction permit was issued prior to January 1, 1981.
Therefore, from 10CFR50.55a(g)a, the following applies:
.components (including supports) shall meet the requirements of paragraphs (g)(4) and (5) of this section to the extent practical.."
Paragraph (g)(4) of 10CFR50.55(a) requires that code class components meet the requirements of later code editions that become effective with the exception of the design and access provisions. It further states that these requirements shall be met to the extent practical within the limitations of design, geometry and materials of construction of the components. Paragraph (g)(5) allows licensees to request relief from the requirements determined to be impractical. The Robinson Plant design did not incorporate the flow instrumentation necessary to meet Section XI 1977 Edition, Sumer 1978 Addenda requirements under all operating modes. Flow measurement must be conducted under specific modes of operation or by placing the equipment in a configuration that prevents it's normal function, thus placing the unit in a.
Limiting Condition for Operation. Therefore, alternate testing is requested for selected equipment.
Pump operating assessments will be made quarterly using differential pressure measurements. In addition, flow, differential pressure and vibration will be measured at cold shutdown to supplement the testing performed quarterly. This test will measure the flow rate of the boric acid transfer pumps by performing a volume verses run time calculation. The test will pump the contents of one storage tank to the other. The level drop in one tank will be quantified and divided by the pump run time to determine the flow rate. Due to the valve lineup required, one boric acid pump at a time will be isolated during the test. This will place the plant in an LCO condition if the test is performed in any condition other than cold shutdown. Therefore, this test will be performed at cold shutdown to preclude removing one train of safety related equipment from service when the RCS temperature exceeds 200 degrees.
2.7.1.1.2 Evaluation--Section XI, Paragraph IWP-4600 requires flow rate to be measured using a rate or quantity meter. The data obtained using 18
the licensee's proposed method, to compute flow rate based on the rate of change of the boric acid storage tank level, would be sufficient for assessing the hydraulic performance of these pumps provided this method meets the accuracy requirements of the Code.
The H. B. Robinson Technical Specifications require both boric acid transfer pumps to be operable during power operation. If one pump is inoperable, the Technical Specification Limiting Condition for Operation (LCO) Action Statement requires the plant to be shutdown unless operability is restored within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The licensee's proposed alternative requires isolating the pump being tested. However, the licensee has not demonstrated that it is impracticable to perform quarterly pump testing and return the pump to operable status within the Technical Specification time limitation.
Therefore, the pumps should be tested, and the pump flow rate calculated, quarterly during power operation.
Based on the determination that computation of pump flow rate would provide an acceptable level of quality and safety, relief from the IWP-4600 flow rate measurement method requirements may be granted provided the licensee's method of computation is within the accuracy that would result from using instruments meeting the Code accuracy requirements. However, relief should not be granted to perform pump testing during cold shutdowns.
2.8 Diesel Fuel Oil Transfer Pumps 2.8.1 Flow Rate Measurement 2.8.1.1 Relief Request. The licensee has requested relief from the differential pressure measurement requirements of Section XI, Paragraph IWP-3100, and the flow rate measurement method and accuracy requirements of Paragraphs IWP-4600 and 4110, respectively, for the diesel fuel oil transfer pumps A and B. The licensee has proposed calculating the pump flow rate based on the rate of level change in the diesel fuel oil day tank.
2.8.1.1.1 Licensee's Basis For Reauestina Relief--These pumps will be tested quarterly by determining the amount of time necessary to refill the 19
diesel fuel oil day tank to a given level.
These time and volume values will then be converted to gallons per minute flow rate. No flow instrumentation is installed in this system. These are rotary pumps which deliver the same volume of liquid regardless of the discharge pressure. Therefore, differential pressure is not a limiting parameter. This method will adequately assess the flow delivery capability of the Transfer Pumps.
However, using this method, +/-2% accuracy cannot be assured. Relief from the
+2% accuracy requirement of Table IWP-4110-1 is requested.
The alternative testing will consist of using a time and volume calculation at quarterly intervals to determine flow rate is considered adequate to determine the above pumps' performance.
2.8.1.1.2 Evaluation--The discharge pressure of positive displacement pumps is dependant on the pressure of the system into which they are pumping and is not affected significantly by either inlet pressure (providing adequate net positive suction head exists) or flowrate. For these pumps differential pressure and flow rate are not dependant variables, as they are for centrifugal type pumps. Pump degradation may result in the loss of capacity at higher pressures. However, these pumps supply fuel oil to a vented tank and the pressure developed at the discharge of the pump is due only to flow resistance in the system piping. Differential pressure is not a meaningful parameter for determining if hydraulic degradation is occurring in these pumps.
Section XI, Paragraph IWP-4600 requires pump flow rate to be measured using a rate or quantity meter. The data obtained using the licensee's proposed method, to compute flow rate based on the rate of change of the diesel fuel oil day tank level, would be sufficient for assessing the hydraulic performance of these pumps provided this method meets the accuracy requirements of IWP-4110.
The licensee has stated that achieving the Code required measurement accuracy cannot be assured. However, the licensee has neither identified the accuracy that can be attained by computing pump flow rate nor shown that the achievable accuracy would be adequate to detect degradation. The licensee 20
should determine the accuracy that can be attained by computation of flow rate based on the rate of change of level in the diesel fuel oil tank. Since flow rate cannot be computed to the Code required accuracy, then either flow rate instrumentation which meets the Code requirements should be installed, or a relief request containing the above information should be submitted for evaluation.
Based on the determination that testing these pumps without measuring differential pressure would provide an acceptable level of quality and safety, relief from the IWP-3100 differential pressure measurements may be granted. Since the Code required accuracy is not attainable, an interim period is necessary to give the licensee time to complete their investigation, the test procedures, any necessary system design changes, or to submit a new relief request. While the current testing may not be adequate to fully access the hydraulic condition or degradation of these pumps, it would be sufficient to demonstrate that the pumps are operable and would provide reasonable assurance of operational readiness in the interim.
Imposition of immediate compliance would cause an extended outage which would result in hardship for the licensee without a compensating increase in safety. Therefore, in this case, interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives.
2.9 Charging Pumps 2.9.1 Differential Pressure Measurement 2.9.1.1 Relief Request. The licensee has requested relief from the differential pressure measurement requirements of Section XI, 'Paragraph IWP-3100, for charging pumps CVC-A, B, and C. The licensee has proposed measuring flow rate at a reference rotative speed.
2.9.1.1.1 Licensee's Basis For Requesting Relief--The charging pumps are positive displacement pumps, therefore, differential pressure is not a limiting parameter. The quantity of the discharge is the same for a given speed regardless of the discharge pressure. The pump cylinder volume 21
is fixed making rotative speed the controlling variable affecting the flow rate.
Pump operability will be determined using flow rate measurements taken at a reference value of rotative speed. Differential pressure will not be measured.
2.9.1.1.2 Evaluation--The outlet pressure of positive displacement pumps is dependant on the pressure of the system into which they are pumping and is not affected significantly by either inlet pressure (providing adequate net positive suction head exists) or flowrate. For these pumps, differential pressure and flow rate are not dependant variables, as they are for centrifugal type pumps.
Differential pressure is not a meaningful parameter in determining if hydraulic degradation is occurring and testing these pumps without measuring differential pressure would provide an acceptable level of quality and safety. However, since pump degradation may result in the loss of capacity at higher pressures, flow rate measurement (at a reference speed) should be performed at a reference discharge pressure which is equal to or greater than the pressure at which the pump would be required to perform its safety function. Further, the measured values of flow should be compared to reference values and have acceptance criteria applied, as outlined by Paragraph IWP-3100.
Based on the determination that testing these pumps without differential pressure measurement would provide an acceptable level or quality and safety, relief may be granted provided the licensee performs the pump testing at a reference discharge pressure.
2.10 Component Cooling Water Pumps 2.10.1 Flow Rate Measurement 2.10.1.1 Relief Request. The licensee has requested relief from the flow rate measurement frequency requirements of Section XI, Paragraph IWP-3100, for the component cooling water pumps CCW-A, B, and C. The licensee has proposed to measure flow using the gauge in the spent fuel heat exchanger cooling line at a refueling outage frequency.
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2.10.1.1.1 Licensee's Basis For Reauesting Relief--The Robinson Plant did-not incorporate the flow instrumentation necessary to meet Section XI 1977 Edition, Summer 1978 Addenda requirements. Therefore, this flow measurement would require a plant design change. This design change is exempted based on 10CFR50.55a(g)(4) and (g)(5) guidelines due to the date of issue of the Robinson construction permit. These pumps are tested in essentially fixed resistance loops during normal operation. Quarterly testing and operability assessments will be based on differential pressure readings. This practice is allowed by the 1974 Edition Summer 1975 Addenda of Section XI.
A refueling interval test will be performed which will allow measurement of pump flow, differential pressure, and vibration. The refueling interval is chosen due to the need to isolate components from the supply header in order to account for all the flow from the pumps. FI-622 in the cooling water supply to the spent fuel heat exchanger will be used to measure pump flow. Other loads on the component cooling water system will be isolated as practicable during the test.
2.10.1.1.2 Evaluation--Component cooling water pump flow can be measured using the installed flow instruments in the line used to cool the spent fuel heat exchanger. However, measuring total pump flow using this flow path requires isolating other cooling loads which are essential during power operation. Therefore, quarterly measurement of component cooling water pump flow is impractical during power operation.
Measurement of pump flow rate during quarterly testing could only be accomplished after significant system modifications, which would be burdensome for the licensee due to the cost involved.
In cases where flow can only be established through a non-instrumented path quarterly and a path exists at cold shutdowns or refueling outages to perform pump testing under full or substantial flow conditions, the staff has determined that the increased interval is an acceptable alternative to the Code requirements provided that pump differential pressure, flow rate, and bearing vibration measurements are taken and analyzed during this testing and 23
O that quarterly testing measuring at least pump differential pressure and vi;-ation is continued. This staff position is outlined in Generic Letter No. 89-04, Attachment 1, Item 9.
Based on the determination that compliance with the Code requirements is impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted provided the licensee conforms to the staff position of Generic Letter No. 89-04, Attachment 1, Item 9.
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- 3. VALVE TESTING PROGRAM The H. B. Robinson Steam Electric Plant, Unit 2, IST program submitted by Carolina Power and Light Company was examined to verify that all valves that are included in the program are subjected to the periodic tests required by the ASME Code,Section XI, 1977 Edition through Summer 1978 Addenda, and the NRC positions and guidelines. The reviewers found that, except as noted in Appendix B or where specific relief from testing has been requested, these valves are tested to the Code requirements and the NRC positions and guidelines. Each Carolina Power and Light Company basis for requesting relief from the valve testing requirements, and the reviewer's evaluation of that request, are summarized below and grouped according to system and valve category.
3.1 General Relief Requests 3.1.1 Leak Rate Testing of Containment Isolation Valves 3.1.1.1 Relief Request. The licensee has requested relief from the leak rate testing requirements of Section XI, Paragraph IWV-3420, for all containment isolation valves. The licensee has proposed performing 10 CFR 50 Appendix J, Type C, leak rate testing at a refueling outage frequency.
3.1.1.1.1 Licensee's Basis For Requesting Relief--10 CFR 50, Appendix J requires periodic leak testing of containment isolation valves.
All section XI Category A valves for this plant are containment isolation valves and require Section XI leak testing. In order to preclude redundant test requirements of these valves, the Appendix J requirement's will be met in lieu of Section XI requirements.
The H. B. Robinson containment has two features in its design that assure adequate integrity during and following a loss of coolant accident.
These are the isolation valve seal water (IVSW) system and the penetration pressurization (PPS) system. These two systems are conservatively designed, seismological qualified, and operated in accordance with Unit Technical Specifications and the requirements of 10 CFR 50, Appendix J, for seal 25
systems that can be used in lieu of local Type C valve testing. The PPS and IVSW systems will be tested as required by 10 CFR 50, Appendix J.
3.1.1.1.2 Evaluation--This relief request is still under staff review.
3.2 Main Steam System 3.2.1 Category C Valves 3.2.1.1 Relief Request. The licensee has requested relief from the check valve exercising frequency and method requirements of Section XI, Paragraph IWV-3520, for the main steam header check valves, MS-261A, B, and C. The licensee has proposed verifying the closure capability of these check valves using disassembly and inspection on a sampling basis at a refueling outage frequency.
3.2.1.1.1 Licensee's Basis For Requesting Relief--These valves are the main steam check valves downstream of the MSIVs. Normal steam flow verifies the proper opening of the valves.Section XI requires reverse flow seating of the valves. These valves cannot be exercised shut during power operation since this wqqld result in a plant trip. Verifying closure of these valves during cold shutdown could result in delaying start-up due to the complicated test methods needed to verify closure (i.e., valve disassembly or visual inspection from inside the main steam lines). Also, since these valves are non-isolable during power operation, any steam leaks of appreciable size would require a plant shutdown to correct. Therefore, since disassembly on a frequent basis would increase the probability of such leaks, such maintenance is not considered a feasible alternative.
These valves will be verified shut during refueling outages by disassembly on a rotating basis (i.e. one valve each refueling). If a problem is noted with a valve during an outage inspection, the other two valves will be inspected also.
3.2.1.1.2 Evaluation--Closure of these valves during power operation is not practical because it would result in a loss of steam flow 26
nd subsequent reactor trip. With the present system design, verifying the losure of these valves by leak testing or with reverse flow is not possible. Significant system modifications would be necessary to enable this testing. These modifications would be burdensome for the licensee due to the costs involved.
The Minutes of the Public Meeting on Generic Letter No. 89-04 state that the use of disassembly to verify closure capability may be acceptable depending on whether verification by flow or pressure measurements is possible. The Minutes of the Public Meeting on Generic Letter No. 89-04 also state that partial-stroke exercise testing with flow is expected to be performed after valve disassembly and inspection is completed, but before returning the valve to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
The licensee's disassembly program, combined with a part-stroke exercise test after reassembly, should adequately determine valve condition and leprovide a reasonable alternative to the Code requirements. Check valve disassembly is a valuable maintenance tool that can provide a great deal of information about a valve's internal condition and, as such, should be performed under the maintenance program at a frequency commensurate with the valve type and service. However, the NRC staff considers valve disassembly and inspection to be a maintenance procedure that is 'not equivalent to the Code required exercise testing. This procedure has risks which may make its routine use as a substitute for testing undesirable when some other method of testing is possible. The licensee should actively pursue the use of non-intrusive diagnostic techniques such as acoustics or radiography to demonstrate that these valves close when subjected to reverse flow conditions.
Based on the determination that it is impractical to verify the reverse flow closure capability of these valves by leak testing or observation of system parameters, that the licensee's proposed alternative would provide reasonable assurance that they are capable of performing their safety function in the closed position, and considering the burden on the licensee 27
if the Code requirements were imposed, relief may be granted provided the licensee part-stroke exercises the valves to the open position with flow after they have been reassembled. The licensee should investigate ways, other than disassembly and inspection, of verifying the reverse flow closure capability of these valves.
3.3 Safety Injection System 3.3.1 Category C Valves 3.3.1.1 Relief Request. The licensee has requested relief from the check valve exercising frequency and method requirements of Section XI, Paragraph IWV-3521, for the accumulator discharge check valves, SI-875D, 875E, and 875F. The licensee has proposed part-stroke exercising these valves during cold shutdowns and verifying their full-stroke operability using disassembly and inspection on a sampling basis at a refueling outage frequency.
3.3.1.1.1 Licensee's Basis For Reauesting Relief--These accumulator check valves are partially stroked at cold shutdown by varying reactor coolant system pressure and observing increases and decreases in accumulator level.
Stroke verification by passing design flow during cold shutdown or refueling outages is not practical due to the large volume of water that would be added to the reactor coolant system and the lack of instrumentation to measure discharge rate. During accident conditions, these check valves will function if reactor coolant system (RCS) pressure drops below approximately 600 psi.
Calculations have shown that a differential pressure of approximately 25 psi will shear any particles that may attempt to prevent the valve from functioning (FSAR Section 6.2.3). These measurements are considered adequate to verify opening of the valve.
These valves will be disassembled for full stroke verification each refueling on a rotating basis (i.e. one valve each refueling). The partial stroke test will continue at cold shutdown.
3.3.1.1.2 Evaluation--Demonstration of a full-stroke exercise of check valves with flow requires the passage of the maximum required accident 28
flow rate through the valves. The only full-flow test path for exercising these valves is into the RCS. These valves cannot be full-or part-stroke exercised with flow quarterly during power operation because RCS pressure is greater than accumulator pressure. During cold shutdown, a full-stroke exercise cannot be accomplished because it could lead to a low-temperature overpressurization of the RCS due to the lack of expansion volume necessary to accommodate the large quantity of water which must be discharged into the RCS. Further, this flow path is not equipped with the flow rate instrumentation necessary to verify a full-stroke of these check valves.
The Code required testing could only be performed after significant system modifications, such as installation of a full flow test loop for exercising these valves, which would be burdensome for the licensee due to the cost involved. Further, the addition of valves and piping penetrations could result in reduced plant reliability.
The licensee has proposed verifying the full-stroke open capability of these check valves using sample disassembly and inspection. The NRC staff positions regarding check valve disassembly and inspection are explained in detail in Generic Letter No. 89-04, "Guidance on Developing Acceptable Inservice Testing Programs." The minutes on the public meetings on Generic Letter No. 89-04 regarding Position 2, Alternatives to Full Flow Testing of Check Valves, further stipulate that a partial stroke exercise test using flow is expected to be performed after disassembly and inspection is completed but before the valve is returned to service. This post-inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
The licensee's proposed alternative, combined with a part-stroke exercise test of the reassembled valves, would provide reasonable assurance of operational readiness. However, the NRC staff considers valve disassembly and inspection to be a maintenance procedure with inherent risks which make its routine use as a substitute for testing undesirable when other testing methods are possible. It may be possible to verify that these valves move to their fully open position by use of non-intrusive diagnostic testing techniques during a reduced flow test at least once each refueling outage.
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Based on the determination that the Code required testing is impractical, that the licensee's proposed alternative provides reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee performs a partial flow test of the disassembled valves before they are returned to service following the disassembly and inspection procedure. The licensee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves swing fully open during partial flow testing.
3.3.1.2 Relief Reauest.
The licensee has requested relief from the check valve exercising frequency requirements of Section XI, IWV-3521, for the following safety injection (SI) system cold leg injection check valves.
The licensee has proposed full-stroke exercising these check valves using flow during refueling outages.
SI-873A SI-873B SI-873C SI-873D SI-873E SI-873F SI-874A SI-8748 3.3.1.2.1 Licensee's Basis For Reuestin_ Relief--These valves cannot be full-stroke exercised during normal operation due to the difference in pressure between the RCS (2235 psig) and the discharge head of the SI pumps (1500 psig).
Injection into the RCS during cold shutdown is not desirable due to the possibility for low temperature overpressurization of the RCS.
At refueling intervals, these valves are full stroked during the Safety Injection System Test while the Reactor Vessel Head is removed and the Refueling Cavity can be filled. This constitutes the only practical interval that this test can be performed.
3.3.1.2.2 Evaluation--Demonstration of a full-stroke exercise of check valves with flow requires the passage of the maximum required accident flow rate through the valves. The only full-flow test path for exercising these valves is into the RCS. These check valves cannot be full-or part-stroke exercised with flow quarterly during power operation because the shutoff head of the safety injection pumps is less than normal 30
RCS pressure. Exercising these check valves with flow during cold shutdowns could result in a low-temperature overpressurization of the RCS.
The Code required testing could only be performed at the Code required frequency after significant system modifications, such as the installation of a full flow test loop for exercising these valves, which would be burdensome for the licensee due to the cost involved. Further, the addition of valves and piping penetrations could result in reduced plant reliability.
A valid full-stroke exercise with flow requires that the flow through the valve be known. Knowledge of only the total flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise. The safety injection system P&IDs (5379-1082, sheets 1-5) supplied by the licensee do not show installed flow instruments capable of individually verifying a full-stroke exercise of these valves with flow. The licensee's proposed alternative, full-stroke exercising these check valves with flow at a refueling outage frequency when filling the refueling cavity would provide reasonable assurance of operational readiness provided the licensee individually verifies the full-stroke capability of each valve. The NRC staff position regarding full flow testing of check valves is explained in detail in Generic Letter No. 89-04, Attachment 1, Item 1.
Based on the determination that the Code requirements are impractical, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee conforms to the position of Generic Letter No. 89-04, Attachment 1, Item 1.
3.3.1.3 Relief Request. The licensee has requested relief from the check valve exercising frequency requirements of Section XI, Paragraph IWV-3521, for the safety injection pump discharge check valves, SI-879A, 879B, and 879C. The licensee has proposed part-stroke exercising these check valves quarterly and full-stroke exercising them at a refueling outage frequency.
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3.3.1.3.1 Licensee's Basis For Reauestina Relief--These valves cannot be full-stroke exercised during normal operation due to the difference in pressure between the RCS (2235 psig) and the discharge head of the SI pumps (1500 psig).
Design flow through these valves cannot be achieved with the system aligned for miniflow recirculation. Injection into the RCS via the SI pumps during cold shutdown is not desirable due to the possibility for low temperature overpressurization of the RCS.
These valves pass design flow at refueling outages during the SI system flow test. These valves are partial-stroke exercised quarterly by observing pressure increase from PT-943 when each safety injection pump is tested.
3.3.1.3.2 Evaluation--Demonstration of a full-stroke exercise of check valves with flow requires the passage of the maximum required accident flow rate through the valves. The only full-flow test path for exercising these valves is into the RCS. These check valves cannot be full-stroke exercised with flow quarterly during power operation because the shutoff head of the safety injection pumps is less than normal RCS pressure. Full-stroke exercising these check valves with flow during cold shutdowns could result in a low-temperature overpressurization of the RCS.
Part-stroke exercising these valves quarterly and full-stroke exercising them during refueling outages would provide reasonable assurance of operational readiness.
The Code required testing could only be performed at the Code required frequency after significant system modifications, such as installation of a full flow test loop for exercising these valves, which would be burdensome for the licensee due to the cost involved.
Based on the determination that the Code requirements are impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3.1.4 Relief Reauest. The licensee has requested relief from the check valve exercising frequency and method requirements of Section XI, 32
Paragraph IWV-3521, for the containment spray pump discharge check valves, SI-890A and 890B. The licensee has proposed part-stroke exercising these valves during cold shutdowns with air and verifying their full-stroke operability using disassembly and inspection on a sampling basis at a refueling outage frequency.
3.3.1.4.1 Licensee's Basis For Reguesting Relief--These valves are partial stroke tested at cold shutdown by injecting air upstream and observing a pressure increase on a temporary test gauge downstream. The cold shutdown test constitutes the only method to verify disk travel short of initiating flow through the spray nozzles or disassembly.
These valves are disassembled and manually stroked at refueling on a rotating basis (i.e. one valve each refueling). If a problem is noted with a valve during an outage inspection, the other valve will be inspected for full-stroke operation also.
3.3.1.4.2 Evaluation--These check valves are in the discharge line of the containment spray pumps. Exercising these check valves with flow using the containment spray pumps, in any Mode of plant operation, would result in spraying down the containment building which could cause equipment damage.
The Code required testing could only be performed after significant system modifications, such as installation of a full flow test loop for exercising these valves, which would be burdensome for the licensee due to the cost involved. Further, the addition of valves and piping penetrations could result in reduced plant reliability.
The licensee has proposed verifying the full-stroke open capability of these check valves using sample disassembly and inspection. The NRC staff positions regarding check valve disassembly and inspection are explained in detail in Generic Letter No. 89-04, "Guidance on Developing Acceptable Inservice Testing Programs." The minutes on the public meetings on Generic Letter No. 89-04 regarding Position 2, Alternatives to Full Flow Testing of Check Valves, further stipulate that a partial stroke exercise test using 33
flow is expected to be performed after disassembly and inspection is completed but before the valve is returned to service. This post-inspection testing provides a degree of confidence that the disassembled-valve has been reassembled properly and that the disk moves freely.
The licensee's proposed alternative, combined with a part-stroke exercise test of the reassembled valves, would provide reasonable assurance of operational readiness. However, the NRC staff considers valve disassembly and inspection to be a maintenance procedure with inherent risks which make its routine use as a substitute for testing undesirable when other testing methods are possible. It may be possible to verify that these valves move to their fully open position by use of non-intrusive diagnostic testing techniques during a reduced flow test at least once each refueling outage.
Based on the determination that the Code required testing is impractical, that the licensee's proposed alternative provides reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee performs a partial flow test of the disassembled valves before they are returned to service following the disassembly and inspection procedure. The licensee should actively pursue the use of non-intrusive diagnostic techniques to determine whether they can be used to demonstrate full-stroke exercising during partial flow testing.
3.3.1.5 Relief Request. The licensee has requested relief from the quarterly check valve exercising requirements of Section XI, Paragraph IWV-3521, for spray additive tank vacuum breaker valves, SI-8990 and 899E.
The licensee has proposed bench testing these special vacuum breaker check valves at refueling outages.
3.3.1.5.1 Licensee'sBasis For Reuesting Relief--Removal of valves 899D and 899E for exercising during power operation would render containment spray additive subsystem inoperable. During cold shutdown, removal for exercising on a test stand could delay startup. Due to the 34
special techniques that must be performed to ensure the vacuum breaking capability of these valves, a refueling test frequency is required. A classification of C-active has been chosen for these valves. A modification has been performed to allow bench testing of these valves.
3.3.1.5.2 Evaluation--The only practical method for verifying proper operability of these special vacuum breaker check valves is removal of the valves from the system and bench testing with a special test assembly. Removal of these valves during power operation would render the containment spray additive subsystem inoperable. Performing this testing during cold shutdowns would require a significant amount of time for valve removal, test performance, and valve installation and could result in a delay in the return to power. These delays, and the increased expense and manpower requirements due to testing at a cold shutdown frequency would be burdensome for the licensee due to the costs involved. Further, due to the infrequent occurrence of cold shutdowns of long duration, the extra expense and manpower requirements necessary to perform this testing during cold shutdowns would not yield a significant increase in assurance in operational readiness. The licensee's proposal, to bench test these vacuum breaker valves during refueling outages would provide reasonable assurance of operational readiness.
Based on the deterfiination that the Code requirements are impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted as requested.
3.3.1.6 Relief Reauest.
The licensee has requested relief from the check valve exercising requirements of Section XI, Paragraph IWV-3521, for the residual heat removal (RHR) system cold leg injection check valves, SI-876A, 876B, 876C, and the combined RHR/SI/accumulator cold leg injection check valves, SI-875A, 875B, 875C. The licensee has proposed exercising these check valves with flow during cold shutdowns and refueling outages.
3.3.1.6.1 Licensee's Basis For Reguesting Relif--These valves cannot be cycled quarterly due to the RCS pressure being greater than the 35
SI and RHR pump shutoff head and the operating pressure of the accumulators. These valves are cycled during cold shutdown by passing RHR system flow. However, the flow through each valve cannot be positively determined using equipment presently installed. The ability of each valve to pass full flow is accepted.
To supplement this cold shutdown testing, the valves will be full stroke exercised at refueling intervals. This testing will be accomplished by aligning valves RHR-744A, RHR-744B, and SI-885 to divert RHR pump discharge to "B" RCS loop with "A" and "C" loops isolated; then, to "A" and "C"
loops with the "B" loop isolated. By monitoring RHR pump flow rates, the quantity of discharge into the loops can then be determined. This test will positively prove that the cold shutdown testing is adequate to assess valve operability. This supplemental testing places the RHR system in an abnormal alignment requiring considerable coordination. Therefore, it will not be performed at cold shutdown. It is intended as a proof test of the normal cold shutdown testing and will be performed under the more stable conditions of a refueling outage.
Cold shutdown testing using RHR system flow will continue. As a supplemental proof test, the valves will be full-stroked using diverted RHR flow at refueling intervals.
3.3.1.6.2 Evaluation--The only available flow path for full-stroke exercising these check valves with flow is into the RCS. These check valves cannot be full-or part-stroke exercised with flow quarterly during power operation because neither the SI nor the RHR pumps can develop the head necessary to overcome normal RCS pressure. The RHR system provides reactor core cooling for decay heat removal during cold shutdowns. The licensee's proposal, to use diverted RHR flow for exercising these valves, would require placing the RHR system in an abnormal alignment. The possibility exists that cooling water flow to the core could be disrupted if this testing were performed during cold shutdowns.
Check valves SI-876A, 8, and C are located in parallel branches of the RHR to RCS cold leg injection lines. Check valves SI-875A, B, and C are 36
located in parallel branches of the combined SI/RHR/accumulator cold leg injection lines to the RCS, downstream of check valves SI-876A, B, and C.
The NRC staff position regarding full flow testing of check valves is that a check valve's full-stroke to the open position may be verified by passing the maximum required accident condition flow through the valve. Any flow rate less than this is considered a part-stroke exercise. A valid full-stroke exercise with flow requires that the flow through the valve to be known. Knowledge of only the total flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise. This staff position is described in detail in Generic Letter No. 89-04, Attachment 1, Item 1. The parallel cold leg injection lines, in which the above valves are located, are not equipped with flow rate instrumentation. Valve SI-876B can be verified to full-stroke, using the pump discharge flow rate instrument, by isolating the "A" and "C" RCS loop injection lines from the RHR pump discharge header. However, due to the system configuration, this method cannot be used for check valves SI-876A and C since these two branches cannot be isolated from each other. The licensee has proposed exercising these two parallel valves with flow while monitoring the total flow to the branch lines, which is contrary to the Generic Letter No. 89-04 position.
Further, the maximum accident flow rate through valves SI-875A, B, and C cannot be achieved using the RHR pumps. Therefore, the licensee's proposed testing for these valves cannot be considered a full-stroke exercise.
An interim period is necessary to give the licensee time to complete their investigation, the test procedures, and any necessary system design changes. Imposition of immediate compliance would cause an extended outage which would result in hardship for the licensee without a compensating increase in safety. Although the licensee's proposed alternative for valves SI-876A, 876C, 875A, 875B, and 875C does not individually verify a full-stroke of each valve, it does provide an indication that the system is capable of performing its design function and would provide reasonable assurance of operational readiness in the interim. Therefore, interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives. It may be possible to verify that these valves move to their fully open position 37
by use of non-intrusive diagnostic testing techniques during flow testing.
The licensee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves swing fully open during flow testing.
3.4 Service Water System 3.4.1 Category C Valves 3.4.1.1 Relief Request. The licensee has requested relief from the check valve exercising frequency and method requirements of Section XI, Paragraph IWV-3521, for the service water backup header to the auxiliary feedwater system check valve, SW-544. The licensee has proposed part-stroke exercising this check valve quarterly and verifying its full-stroke operability using disassembly and inspection every third refueling outage.
3.4.1.1.1 Licensee's Basis For Requesting Relief--This valve is partial-stroke exercised quarterly by verifying flow through a downstream telltale drain. Valve SW-544 is in the service water supply to the auxiliary feedwater (AFW) pump suction line. It is a backup water supply that would only be initiated in emergency conditions (condensate tank level less than 10% with no means of makeup). The deep well water system also serves as a backup AFW pump suction supply source. Locked closed valves are installed downstream of SW-544. Therefore, no flow is introduced through this valve during normal plant operation. Wear due to flow fluctuations is not a concern.
Full-stroke testing can only be accomplished by adding untreated lake water to the AFW system which has controlled water chemistry..Therefore, system design does not allow full-stroke testing. Dismantling the valve at each cold shutdown is not considered necessary nor practical since this would disable portions of the service water system. Disassembly at each refueling for full stroke verification does not add to the safety margin verified by a quarterly partial-stroke test. In fact, disassembly for full-stroke verification may prove detrimental and could possibly add to service water system leakage during operation. Alternate testing is 38
appropriate considering partial stroke testing now being performed quarterly, the redundant role this system shares with the deep well water system, and the absence of flow induced wear.
This valve was disassembled during the 1984 steam generator replacement outage.
Internal conditions and operability of the valve were found to be satisfactory. This valve will be disassembled at every third refueling outage. The starting point for this frequency shall be the 1984 stem generator replacement outage.
3.4.1.1.2 Evaluation--Full-stroke exercising this check valve with flow would cause contamination of the auxiliary feedwater system with raw water which could lead to accelerated corrosion and degradation of the feedwater systems and steam generators. Part-stroke exercising can be accomplished by opening a downstream telltale drain.
The Code required testing could only be performed after significant system modifications, such as a full flow test loop for exercising this valve, which would be burdensome for the licensee due to the cost involved.
The licensee has proposed verifying the full-stroke open capability of these check valves using disassembly and inspection. The NRC staff positions regarding check valve disassembly and inspection are explained in detail in Generic Letter No. 89-04, "Guidance on Developing Acceptable Inservice Testing Programs."
The minutes on the public meetings on Generic Letter No. 89-04 regarding Position 2, Alternatives to Full Flow Testing of Check Valves, further stipulate that a partial stroke exercise test using flow is expected to be performed after disassembly and inspection is completed but before the valve is returned to service. This post-inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
The licensee's proposed alternative, combined with a part-stroke exercise test of the reassembled valves, would provide reasonable assurance of operational readiness. However, the NRC staff considers valve disassembly and inspection to be a maintenance procedure with inherent 39
risks which make its routine use as a substitute for testing undesirable when other testing methods are possible. It may be possible to verify that this valve moves to its fully open position by use of non-intrusive diagnostic testing techniques during a reduced flow test at least once each refueling outage.
The licensee has proposed extending the disassembly interval for this valve to once every third refueling outage. The justification provided is that valve disassembly could result in increased service water system leakage and that the valve was disassembled during the 1984 steam generator outage and found to be in satisfactory condition. The NRC staff position on the extension of the disassembly and inspection interval, as outlined in Generic Letter No. 89-04, is that extension of the interval should only be considered in cases of extreme hardship where the extension is supported by actual in-plant data. The information necessary to support extension of the disassembly and inspection interval is also outlined in Generic Letter No. 89-04, Attachment 1, Item 2. The licensee's justification is not adequate to support extension of the Code required quarterly frequency to once every third refueling outage.
Based on the determination that the Code required testing is impractical, that the licensee's proposed alternative provides reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee disassembles the valve every refueling outage and performs a partial flow test of the disassembled valve before it is returned to service. The licensee is should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that this valve swings fully open during partial flow testing.
3.4.1.2 Relief Request. The licensee has requested relief from the check valve exercising method requirements of Section XI, Paragraph IWV-3522, for the service water to steam driven AFW pump oil cooler check valves, SW-542 and SW-543. The licensee has proposed verifying the full-stroke capability of these two parallel check valves together (collectively) quarterly.
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3.4.1.2.1 Licensee's Basis For Requesting Relief--These valves are installed in parallel, monosyllable flow paths. Therefore, full-stroke verification cannot be performed individually on each valve. Flow through these valves is verified collectively at quarterly intervals.
3.4.1.2.2 Evaluation--A valid full-stroke exercise with flow requires that the flow through the valve be known.
The licensee's proposed alternative does not individually verify the flow rate through each valve and cannot be considered a full-stroke exercise. The proposed testing would be considered successful after passing a minimum flow rate through the valves even though one or both valves could have degraded significantly.
The licensee should develop a testing technique to demonstrate that these valves swing fully open during flow testing. Possible approaches may include installation of flow instrumentation or the use of non-intrusive diagnostic techniques that indicate valve position under flow conditions.
If, after a thorough investigation, it is determined that the full-stroke capability of these valves cannot be demonstrated by testing then the licensee may consider valve disassembly and inspection. The NRC staff positions regarding check valve disassembly and inspection to verify the full-stroke open capability are explained in detail in Generic Letter No.
89-04, Attachment 1, Item 2. The minutes on the public meetings on Generic Letter No. 89-04 regarding this staff position further stipulate that a partial stroke exercise test using flow is expected to be performed after disassembly and inspection is completed but before the disassembled valve is returned to service. This post inspection testing provides a degree of confidence that the disassembled valve has been reassembled properly and that the disk moves freely.
An interim period is necessary to give the licensee time to complete their investigation, the test procedures, and any necessary system design changes.
Imposition of immediate compliance would cause an extended outage which would result in hardship for the licensee without a compensating increase in safety. Although the licensee's proposal, to exercise these parallel valves collectively at a quarterly frequency, does not 41
individually verify the full-stroke capability of each valve, it does demonstrate that the pair of valves are capable of performing their intended safety function. Therefore, interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives.
3.5 Instrument Air System 3.5.1 Category A/C Valves 3.5.1.1 Relief Request. The licensee has requested relief from the quarterly check valve exercising frequency requirements of Section XI, Paragraph IWV-3521, for the instrument air header containment isolation check valve, IA-525. The licensee has proposed verifying the closure capability of this valve by leak rate testing at a refueling outage frequency.
3.5.1.1.1 Licensee's Basis For Requesting Relief--This valve, in the instrument air supply line to containment, cannot be aligned for reverse flow testing during normal operation. Such testing would isolate air to certain valves in containment and would result in a potential plant trip.
A test connection was installed during the 1984 steam generator replacement outage that allows seat leakage testing and reverse flow seating verification. Due to the special setup requirements needed to perform this test, relief from reverse flow seating verification at cold shutdown is requested.
This testing will be performed at refueling intervals coincident with the seat leakage testing.
3.5.1.1.2 Evaluation--Verifying the closure capability of this valve during power operation would result in a loss of instrument air to a number of valves inside containment which are required for plant operation. The loss of air to these air operated valves would result in them moving to their fail-safe position which could result in a plant trip.
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This valve is a containment isolation check valve located inside containment and is, therefore, inaccessible during reactor operation. The only method available to verify valve closure is leak rate testing which would require a containment entry. Testing this valve during cold shutdowns would result in increased radiation doses to plant personnel.
Further, this testing would require a significant amount of time for test equipment setup, test performance, and test equipment removal and could result in a delay in the return to power. These delays, and the increased expense and manpower requirements due to testing at a cold shutdown frequency would be burdensome for the licensee due to the costs involved.
The licensee's proposed testing would provide reasonable assurance of operational readiness. The infrequent occurrence of cold shutdowns of long duration, the extra expense and manpower requirements necessary to perform this testing during cold shutdowns would not yield a significant increase in assurance in operational readiness.
Based on the determination that compliance with the Code requirements are impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted as requested.
3.6 Chemical And Volume Control System 3.6.1 Category C Valves 3.6.1.1 Relief Request. The licensee has requested relief from the check valve exercising frequency requirements of Section XI, Paragraph IWV-3521, for the refueling water storage tank (RWST) to the charging pump suction check valve, CVC-357. The licensee has proposed part-stroke exercising this valve quarterly and full-stroke exercising it at a refueling outage frequency.
3.6.1.1.1 Licensee's Basis For Reauesting Relief--Full-stroke exercising valve 357 during power operation would result in overboration of the RCS, which could result in a plant shutdown. During cold shutdown, 43
full-stroke exercising this valve could result in a low temperature overpressurization of the reactor coolant system (RCS).
This valve will be partial stroke exercised quarterly and full-stroke exercised with flow during refueling outages.
3.6.1.1.2 Evaluation--The only full flow test path available for full-stroke exercising this valve with flow is into the reactor coolant system using the charging pumps. The boric acid concentration of the RWST is significantly greater than the RCS during power operation. Full-stroke exercising this valve with flow during power operation would introduce concentrated boric acid into the RCS via the charging pumps which could result in overboration of the the RCS and a plant trip. During cold shutdown, a full-stroke exercise cannot be accomplished because it could lead to a low-temperature overpressurization of the RCS due to the lack of expansion volume necessary to accommodate the large quantity of water which must be discharged into the RCS.
Full-stroke exercising this valve during refueling outages would provide reasonable assurance of operational readiness.
The Code required testing could only be performed after significant modifications to the system, such as the installation of a full flow test loop for exercising these valves, which would be burdensome for the licensee due to the cost involved.
Based on the determination that compliance with the Code requirements are impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted as requested.
3.7 Diesel Generator Fuel Oil Systems 3.7.1 Cateaory B Valves 3.7.1.1 Relief Reauest. The licensee has requested relief from the stroke timing requirements of Section XI, Paragraph IWV-3413(b), for the 44
diesel engine fuel oil day tank isolation valves, FO-27A, 27B, 29A, and 298. The licensee has proposed verifying operability by observation of increasing diesel generator fuel oil day tank level on a bi-weekly basis.
3.7.1.1.1 Licensee's Basis-For Reguesting Relief--Operators for these valves are designed such that actuation cannot be verified by direct observation of valve stem movement. Additionally, these valves are actuated by automatic signals from other diesel generator system components. Specifically FO-27A, 29A, 27B, and 298 are actuated by the diesel day tank level switches.
The design features of these valves and the inability to accurately determine the time of the actuation signals make cycle timing of these valves impractical.
The fuel oil tank isolation valves are cycled during the biweekly performance of the diesel generator periodic test. During performance of the periodic test, failure of these valves to operate would be evident by failure to fill the fuel oil day tank.
The increased cycle frequency has been determined to be an adequate method of ensuring proper valve operation without cycle timing. Proper operation of these valves is verified by monitoring the diesel fuel oil day tank replenishment.
3.7.1.1.2 Evaluation--These valves are not equipped with individual control switches. Instead, the valves are actuated by the diesel day tank level switches. Further, these valves are not equipped with position indication and the valve design is such that direct observation of stem movement is not possible. These considerations make valve stroke timing impractical using normal methods.
The licensee has proposed verifying valve operability by observing that the fuel oil day tank is being replenished when the diesel fuel oil pumps are in operation on a biweekly basis. However, the licensee's proposal provides no means of detecting valve degradation. The licensee 45
should investigate methods of evaluating the stroke times or some means of non-intrusively quantifying degradation for these valves. If stroke times determined by an alternate method are not sufficiently repeatable to permit trending, the licensee could classify these valves as rapid-acting valves, or establish an appropriate maximum stroke time using the guidelines of Generic Letter No. 89-04, Attachment 1, Position 5 and verify that the stroke times remain under this limit.
It would be burdensome to require the licensee to immediately develop a means of determining valve degradation. An interim period is necessary to give the licensee time to complete their investigation and develop the necessary test procedures. The licensee's proposed alternative, while not acceptable for the long term, would provide reasonable assurance of operational readiness in the interim. Therefore, interim relief may be granted for one year or until the next refueling outage, whichever is greater. During this interim period, the licensee should develop a method of adequately monitoring these valves for degradation.
3.8 Diesel Generator Air Start System 3.8.1 CategorY 8 Valves 3.8.1.1 Relief Request. The licensee has requested relief from the stroke timing requirements of Section XI, Paragraph IWV-3413(b), for the diesel engine air start solenoid valves, DA-19A, 19B, 23A, and 238. The licensee has proposed verifying operability of these valves by observing that the diesel generators start during monthly testing.
3.8.1.1.1 Licensee's Basis For Reauesting Relief--Operators for these valves are designed such that actuation cannot be verified by direct observation of valve stem movement. Additionally, these valves are actuated by automatic signals from other diesel generator system components. The diesel air start solenoid valves are actuated in the diesel start sequence. The design features of these valves and the inability to accurately determine the time of the actuation signals make cycle timing of these valves impractical.
The air start solenoids are cycled during the biweekly performance of the diesel generator periodic test. However, only one air start solenoid valve per diesel is tested during each biweekly diesel test. The periodic test contains instructions to isolate one of these valves per diesel by closing an upstream valve. The selection of which valve to isolate is based on the date of the test. If the test is to be performed during the first 14 days of the month, one valve per diesel would be isolated. For a test performed on or after the 15th of the month, the other valve would be isolated. Therefore, each air start valve is tested on a monthly basis.
During performance of the periodic test, failure of these valves to operate would be evident by failure of the diesel to start. The increased cycle frequency has been determined to be an adequate method of ensuring proper valve operation without cycle timing. Proper operation of these valves is verified by the starting of the emergency diesel generator.
3.8.1.1.2 Evaluation--Stroke timing these rapid-acting solenoid valves is not practical because they are not equipped with position indication and valve stem movement cannot be observed.
The purpose of valve stroke timing is to obtain a measure of valve degradation in order to provide assurance of continued operational readiness. The licensee has proposed verifying valve operability by observing that the diesel starts, which would provide no indication of valve degradation. Therefore, the licensee should add additional acceptance criteria to ensure that the proposed testing would provide reasonable assurance of operational readiness. Since valve degradation would be evidenced by increased diesel starting time, measuring the diesel start time and assigning a maximum limiting start time for a satisfactory valve test should provide an indication of degradation and reasonable assurance of operational readiness. This maximum start time should be less than or equal to the Technical Specification requirement.
These valves could be tested to the Code requirements only after significant redesign and modifications to the control circuitry for these 47
valves, such as the addition of individual control switches and valve position indication. Modifications to add position indication for these solenoid valves may not be possible due to the valve design. Therefore, addition of valve position indication may also require valve replacement with a design which would make indication of valve position possible.
These modifications would be burdensome for the licensee due to the cost involved.
Based on the determination that compliance with the Code requirements are impractical, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee's acceptance criteria for the proposed testing is expanded to include a maximum limiting diesel start time which is less than or equal to the Technical Specification limit.
3.9 Auxiliary Feedwater System (Steam Supply) 3.9.1 Category C Valves 3.9.1.1 Relief Reauest. The licensee has requested relief from the requirements of Section XI, Paragraph IWV-3416, that valves in a system which is inoperable or not required to be operable be exercised within 30 days prior to the return of the system to operable status, for the steam driven auxiliary feedwater pump steam supply valves, MS-263A, B, and C.
The licensee has proposed testing these valves within one week after commencing power operation (greater than 2%) or prior to reaching cold shutdown.
3.9.1.1.1 Licensee's Basis For Reauestina Relief--These valves are in the lines that supply steam to the steam driven auxiliary feedwater pump. Adequate steam supply is not available to power the the steam driven auxiliary feedwater pump and thereby verify full flow through these valves prior to leaving cold shutdown conditions.
These valves will be tested within one week after commencing power operation (greater than 2%) or prior to reaching cold shutdown. This will 48
apply only to situations in which the normal quarterly interval for testing was exceeded during the shutdown.
3.9.1.1.2 Evaluation--These valves are located in the steam supply lines to the turbine driven auxiliary feedwater pump. The steam necessary to full-stroke exercise these valves is not available during cold shutdowns or refueling outages, therefore, it is impractical to exercise these valves within 30 days prior to returning the main steam and auxiliary feedwater systems to service as required by the Code. The licensee's proposal, to full-stroke exercise these valves prior to entering cold shutdown or within one week after commencing power operation provides reasonable assurance of operational readiness and is a reasonable alternative to the Code requirements.
There are no steam flow detectors installed in the lines to the steam driven auxiliary feedwater pump, therefore, demonstration of a full stroke of these valves to the open position requires running the pump at the maximum accident required flow. Performance of the Code required testing could only be achieved after significant system modifications to enable verification of either the flow rate through the valves or the actual valve disk position and to allow the use of some other pressurized fluid source to provide the motive force to stroke the valves. These modifications would be burdensome due to the costs involved, and would not provide a significant increase in assurance of operational readiness.
Based on the determination that compliance with the Code requirements is impractical, that the proposed testing would provide reasonable assurance of operational readiness, and considering the burden on the licensee if Code requirements were imposed, relief may be granted as requested.
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APPENDIX A P&ID LIST A-1
4-
APPENDIX A P&ID LIST The P&IDs listed below were used during the course of this review.
System P&ID Sheet Revision Main and Extraction Steam System G-190196 1
20 Feedwater Condensate and Air Evac. System G-190197 1
30 4
10 Service and Cooling Water System G-190199 2
22 4
26 5
26 6
22 7
24 9
24 10 22 Primary Makeup Water System G-190202 1
16 Emergency Diesel Generator System G-190204-A 1
9 Fuel Oil System G-190204-D 2
4 Steam Generator Blowdown/Wet Layup System G-190234 1
18 Penetration Pressurization System G-190261 4
12 Isolation Valve Seal Water System G-190262 1
13 HVAC-Turb., Fuel., Aux., & Reactor Bldgs.
G-190304 1
21 Chemical and Volume Control System 5379-685 1
20 W2 23 3
20 Chemical and Volume Control System 5379-686 1
15 Residual Heat Removal System 5379-1484 1
15 Reactor Coolant System 5379-1971 1
22 2
21 Safety Injection System 5379-1082 1
20 2
22 3
19 4
18 5
19 Component Cooling Water System 5379-376 1
20 2
16 3
16 4
18 Liquid Waste Disposal System 5379-920 3
24 Gaseous Waste Disposal System 5379-921 2
13 Cont. Vapor and Pressure Sampling System HBR2-6490 1
7 Post Acc. Cont. Vent & H2 Recomb. System HBR2-6933 1
6 Primary Sample System 5379-353 1
14 Fire Protection System HBR2-8255 2
11 0
A-3
APPENDIX B IST PROGRAM ANOMALIES IDENTIFIED DURING THE REVIEW B-1
B-'
APPENDIX B IST PROGRAM ANOMALIES FOUND DURING THE REVIEW Inconsistencies and omissions in the licensee's program noted during the course of this review are summarized below. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
- 1. Pump relief request 5.2.9 proposes calculating the inlet pressure by using the height of water in the vented suction source for numerous pumps in the IST program. Relief may be granted provided the licensee's method of suction pressure calculation meets the accuracy requirements of the Code. (Reference Section 2.2.1 of this report.)
- 2. Pump relief request 5.2.4 states that flow will be measured to the accuracy allowed by existing plant instrumentation. To obtain relief from the accuracy measurement requirements of IWP-4100, the licensee must request specific relief from the Code requirements. To obtain relief, the licensee's relief request should indicate the specific plant instrumentation that does not meet the accuracy requirements of IWP-4100, the actual accuracy of the instrumentation, and should show that these instruments will yield indications sufficiently accurate to monitor pump condition and detect degradation. Relief may be granted from the quarterly flow rate measurement requirements for the auxiliary feedwater, safety injection, and residual heat removal pumps provided the licensee conforms to the position of Generic Letter No. 89-04, Attachment 1, Item 9. Relief from the direct flow rate measurement requirements of IWP-4600 may be granted for the boric acid transfer pumps provided the licensee's method of computation meets the accuracy requirements of the Code. However, since the licensee has not demonstrated that it is impractical to perform quarterly pump testing and return the pump to operable status within the Technical Specification time limitation, relief from the quarterly flow rate measurement requirements should not be granted for the boric acid pumps.
(Reference Sections 2.3.1, 2.5.1, 2.6.1, and 2.7.1 of this report.)
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- 3. Pump relief request 5.2.3 proposes measuring discharge pressure and vibration quarterly with a "dead head" pressure test at refueling outages for the service water pumps. The licensee's proposal to determine each pump's contribution to total system pressure when it is started in parallel with the running pumps combined with performance of a "dead head" pressure test during refueling outages is not adequate to fully access the hydraulic condition of these pumps. The licensee should investigate methods of determining differential pressure and flow rates for these pumps and interim relief may be granted for one year or until the next refueling outage, whichever is greater, while the licensee investigates the feasibility of acceptable alternatives. (Reference Section 2.4.1 of this report.)
- 4. Pump relief request 5.2.5 proposes computing the flow rate of the diesel fuel oil transfer pumps based on the rate of level change in the diesel fuel oil day tank. The licensee has stated that achieving the Code required measurement accuracy cannot be assured. However, the licensee has neither identified the accuracy that can be attained by computing pump flow rate nor shown that the achievable accuracy would be adequate to detect degradation. The licensee should.
determine the accuracy that can be attained by computation of flow rate based on the rate of change of level in the diesel fuel oil tank. If the flow rate cannot be computed to the Code required accuracy, then either flow rate instrumentation which meets the Code requirements should be installed, or a relief request containing the above information should be submitted for evaluation. Interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue the current testing methods while the licensee investigates the feasibility of acceptable alternatives. (Reference Section 2.8.1 of this report.)
- 5. Pump relief request 5.2.7 proposes that the operability of the positive displacement charging pumps be determined using flow rate measurements taken at a reference value of rotative speed and that differential pressure not be measured. Since pump degradation may 8-4
result in the loss of capacity at higher pressures, flow rate measurement (at reference speed) should be performed at a reference discharge pressure which is not less than the pressure at which the pump would be required to perform its safety function. Relief may be granted on the condition that the licensee adds this provision to their proposed alternate test.
(Reference Section 2.9.1 of this report.)
- 6. Pump relief request 5.2.8 proposes measuring component cooling water pump flow rate at a refueling outage frequency. Relief may be granted provided the licensee conforms to the position of Generic Letter No. 89-04, Attachment 1, Item 9. (Reference Section 2.10.1 of this report.)
- 7. Pump relief request 5.2.3 states that measurement of the service water pumps' discharge flow is not possible, however, the licensee's valve program indicates that the service water pump discharge check valves, SW-374, 375, 376, and 377, are full-stroke exercised to the open position monthly. Verification of a check valve's full-stroke capability requires the flow through the valve to be known. The licensee should verify that the valve testing outlined in their IST program may indeed be called a full-stroke exercise, and submit a request for relief if the Code required testing cannot be performed.
As guidance, the licensee should refer to Generic Letter No. 89-04,, Item 1.
- 8. P&ID G-190199, sheet 7, indicates a lack of permanently installed flow instrumentation for the service water booster pumps, but the pump tables indicate that flow is measured on a quarterly basis. The licensee should verify that the pump testing outlined in their IST program meets the requirements of the Code and the Generic Letter No. 89-04 positions and should submit a request for relief if the Code required testing cannot be performed.
- 9. Valve Relief Request 5.3.2 proposes verifying the closure capability of the main steam header check valves, MS-261A, B, and C, using B-5
disassembly and inspection on a sampling basis at a refueling outage frequency. The Minutes of the Public Meeting on Generic Letter No.
89-04 state that partial-stroke exercise testing with flow is expected to be performed after valve disassembly and inspection is completed, but before returning the valve to service. Relief may be granted provided the licensee part-stroke exercises the valves to the open position with flow after they have been reassembled. However, the licensee should actively pursue the use of non-intrusive diagnostic techniques such as acoustics or radiography to demonstrate that these valves close when subjected to reverse flow conditions.
If another method is developed to verify the reverse flow closure capability of these valves, this relief request should be revised or withdrawn.
(Reference Section 3.2.1.1 of this report.)
10.. There are no installed steam flow detectors in the lines to the steam driven auxiliary feedwater (AFW) pump, therefore, to verify a full-stroke exercise of the steam driven AFW pump steam supply valves, MS-263A, B, and C, to the open position, it is necessary to O
run the AFW pump at the maximum flow required by any of the plant safety analysis. The licensee has stated that this flow cannot be achieved when at power. The licensee's IST program lists valves MS-263A, B, and C as being full-stroke exercised open at a monthly frequency. The licensee should verify that the valve testing outlined in their IST program may indeed be called a full-stroke exercise, and submit a request for relief or cold shutdown justification if the Code required testing cannot be performed. As guidance, the licensee should refer to Generic Letter No. 89-04, attachment 1, item 1. Further, these valves have a safety function in the closed position to prevent diversion of steam flow. The valve tables indicate they are tested only to the open position; The licensee should verify that these valves are exercised to the closed position.
- 11.
The licensee has proposed using disassembly and inspection to verify the full-stroke open capability of numerous check valves. The NRC staff considers valve disassembly and inspection to be a maintenance B-6
procedure with inherent risks which make its use a a substitute for testing undesirable when other testing methods are possible. The NRC staff positions regarding check valve disassembly and inspection to verify the full-stroke open capability are explained in detail in Generic Letter No. 89-04, Attachment 1, Item 2. The minutes on the public meetings on Generic Letter No. 89-04 regarding this staff position further stipulate that a partial stroke exercise test using flow is expected to be performed after disassembly and inspection is completed but before the valve is returned to service. Valve Relief Requests 5.3.3, 5.3.5, and 5.3.8 may be granted provided the licensee performs a partial flow test of the disassembled valves before they are returned to service and, for Relief Request 5.3.5, the licensee disassembles valve SW-544 every refueling outage. However, the licensee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves swing fully open during partial flow testing. If another method is developed to verify the full-stroke capability of these valves, these relief requests should be revised or withdrawn. (Reference Sections 3.3.1.1, 3.4.1.1, and 3.3.1.4 of this report.)
- 12.
Valve Relief Request 5.3.14 proposes exercising the RHR system cold leg injection check valves, SI-876A, B, and C, and the RHR/SI/accumulator cold leg injection check valves, SI-875A, B, and C with flow during cold shutdowns and refueling outages. Check valves SI-876A, B, and C are located in parallel branches of the RHR to RCS cold leg injection lines. Check valves SI-875A, B, and C are located in parallel branches of the combined SI/RHR/accumulator cold leg injection lines to the RCS, downstream of check valves SI-876A, B, and C. The NRC staff position regarding full flow testing of check valves is that a check valve's full-stroke to the open position may be verified by passing the maximum required accident condition flow through the valve. Any flow rate less than this is considered a part-stroke exercise. Knowledge of only the total flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise. This staff position is described in detail in Generic B-7
Letter No. 89-04, Attachment 1, Item 1. The licensee has proposed exercising valves SI-876A and C with flow while monitoring the total flow to the branch lines, which is contrary to the Generic Letter No.
89-04 position. Further, the maximum accident flow rate through valves SI-875A, B, and C cannot be achieved using the RHR pumps.
Therefore, the licensee's proposed testing for these valves cannot be considered a full-stroke exercise. The licensee should actively pursue the use of non-intrusive diagnostic techniques to demonstrate that these valves swing fully open during partial flow testing.
Interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives. (Reference Section 3.3.1.6 of this report.)
13.. Valve Relief Request 5.2.4 proposes that the following safety injection system cold leg injection check valves be full-stroke exercised with flow during refueling outages. Knowledge of only the total flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise. The NRC staff position regarding full flow testing of check valves is explained in detail in Generic Letter No. 89-04, Attachment 1, Item 1. Relief from the Code check valve exercising frequency requirements may be granted provided the licensee conforms to the position of Generic Letter No. 89-04,, Item 1. (Reference Section 3.3.1.2 of this report.)
SI-873A SI-873B SI-873C SI-873D SI-873E SI-873F SI-874A SI-874B
- 14.
Valve Relief Request 5.3.6 proposes that the service water to the parallel steam driven AFW pump oil cooler check valves, SW-542 and 543, be full-stroke exercised with flow together (collectively).
Knowledge of only the total flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise. This staff position is described in detail in Generic Letter No. 89-04, Attachment 1, Item 1. The licensee should actively pursue the use of non-intrusive 8-8
diagnostic techniques to demonstrate that these valves swing fully open during partial flow testing. If, after a thorough investigation, it is determined that the full-stroke capability of these valves cannot be demonstrated with diagnostic techniques then the licensee may consider valve disassembly and inspection. The NRC staff positions regarding check valve disassembly and inspection to verify the full-stroke open capability are explained in detail in Generic Letter No. 89-04, Attachment 1, Item 2. The minutes on the public meetings on Generic Letter No. 89-04 regarding this staff position further stipulate that a partial stroke exercise test using flow is expected to be performed after disassembly and inspection is completed but before the disassembled valve is returned to service. Interim relief may be granted for one year or until the next refueling outage, whichever is greater, to continue current testing methods while the licensee investigates the feasibility of acceptable alternatives.
(Reference Section 3.4.1.2 of this report.)
- 15.
Valve Relief Request 5.3.12 requests relief from the Code stroke timing requirements for diesel generator air start solenoid valves, DA-19A, 19B, 23A, and 238. The licensee's proposed alternative is to observe that the diesel generators start during monthly testing. The licensee has proposed verifying valve operability by observing that the diesel starts, which would provide no indication of valve degradation. Therefore, the licensee should add additional acceptance criteria to ensure that the proposed testing would provide reasonable assurance of operational readiness. Since valve degradation would be evidenced by increased diesel starting time, measuring the diesel start time and assigning a maximum limiting start time for a satisfactory valve test should provide an indication of degradation.
This maximum start time should be less than or equal to the Technical Specification requirement. Relief may be granted provided the licensee's acceptance criteria for the proposed testing is expanded to include a maximum limiting diesel start time which is less than or equal to the Technical Specification limit. (Reference Section 3.8.1.1 of this report.)
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- 16.
The valve tables show that service water system air operated valves TCV-1660, 1661, 1902A, 1903A and 19038 are stroke timed but not tested to verify remote position indication. The licensee should ensure that the Code required testing is performed on these valves and amend the valve tables accordingly.
- 17.
All valves in the isolation valve seal water system are indicated as Category B or B/C "passive" and the valve tables indicate that no testing is being performed on these valves. These valves do not satisfy the staff definition of passive valves. These valves should be changed to Category A or A/C valves and tested to the Code requirements.
- 18. Check valve SI-894 (P&ID 5379-1082, sheet 1 of 5, C-4) appears to have a safety function in the closed position to prevent diversion of flow. The licensee should review the safety function of this valve and determine if it should be included in the IST program.
- 19. SI-889A and B are check valves in the containment spray NaOH eductor lines. In order to full-stroke exercise these valves to the open position, they must pass the maximum required accident flow rate.
However, based on the licensee's statements in relief request 5.3.8 and and a review of the licensee's containment spray system it does not appear that these valves can be tested to the Code requirements quarterly. The licensee should review the testing being performed on these valves and submit a request for relief or cold shutdown justification if the Code required testing cannot be performed. As guidance, the licensee should refer to Generic Letter No. 89-04,, Item 1.
- 20. The valve tables indicate that the safety injection pump individual recirculation check valves SI-893A, B, and C, and the combined recirculation check valve, SI-839, are forward flow tested monthly.
However, P&ID 5379-1082, sheet 2 of 5 indicates a lack of any installed flow instrumentation in these lines. The licensee should review the current testing of these check valves to verified they are B-10
being tested to the Code requirements. As guidance, the licensee should refer to Generic Letter No. 89-04, Attachment 1, Item 1.
- 21.
The containment spray pump recirculation check valves, SI-8890 and E (P&ID 5379-1082, sheet 3 of 5), appear to have a safety function in the open position for containment spray pump recirculation flow. The licensee should review the safety function of these valves and determine if they should be included in the IST program and tested to the Code requirements.
- 22. The RCS to RHR suction valves, RHR-751 and 752, are categorized "B" in the valve tables. The licensee should evaluate the categorization of these valves to determine if they should be categorized "A".
- 23. In response to the NRC request for additional information dated September 22, 1986, the licensee stated that there are no valves required to be identified as pressure boundary isolation valves and categorized A or A/C. This response was transmitted by letter identified as serial number NLS-86-471. However, Table 3.1-1 of the licensee's Technical Specifications identifies several check valves as pressure isolation valves. The pressure isolation valves listed in the licensee's Technical Specifications should be categorized A/C.
Further, this Techpical Specification list does not appear to be complete. For example, the safety injection cold leg injection check valves via the boron injection tank, 873A, 8, and C, and the safety injection system accumulator discharge check valves, 8750, E, and F, also appear to have a pressure isolation function. The licensee should actively investigate this issue. This issue will remain an open item pending resolution of Generic Issue No. 105.
- 24. Valve Relief Request No. 5.3.1 is still under review.
- 25. In Valve Relief Request No. 5.3.12, the licensee has proposed verifying the operability of the diesel engine fuel oil day tank isolation valves, FO-27A, 27B, 29A, and 298 by observation of increasing diesel generator fuel oil day tank level on a bi-weekly B-11
basis. However, this alternative provides no means of detecting valve degradation. The licensee should investigate methods of evaluating the stroke times or some means of non-intrusively quantifying degradation for these valves. If stroke times determined by an alternate method are not sufficiently repeatable to permit trending, the licensee could classify these valves as rapid-acting valves, or establish an appropriate maximum stroke time using the guidelines of Generic Letter No. 89-04, Attachment 1, Position 5 and verify that the stroke times remain under this limit. Interim relief may be granted for one year or until the next refueling outage, whichever is greater. During this interim period, the licensee should develop a method of adequately monitoring these valves for degradation.
(Reference section 3.7.1.1 of this report.)
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