ML20069Q546
| ML20069Q546 | |
| Person / Time | |
|---|---|
| Site: | Limerick  |
| Issue date: | 01/31/1990 |
| From: | Hemming W, Ransom C, Stockton N EG&G IDAHO, INC., IDAHO NATIONAL ENGINEERING & ENVIRONMENTAL LABORATORY |
| To: | NRC |
| Shared Package | |
| ML20069Q550 | List: |
| References | |
| CON-FIN-A-6811, CON-FIN-A-6812 EGG-NTA-9361, TAC-56245, TAC-71889, NUDOCS 9101160171 | |
| Download: ML20069Q546 (63) | |
Text
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EGG NTA 9361 4
TECHNICAL EVALVATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM LIMERICK GENERATING STATION, UNITS 1 AND 2 Docket Nos. 50-352 and 50 353 N. B. Stockton W. C. Hemming C. B. Ransom Published January 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. DE AC07-761D01570 FIN Nos. A6812 and A6811 TAC Nos. 56245 and 71889
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ABSTRACT This F.G&G Idaho, Inc., report presents the results of our evaluation of the Limerick Generating Station, Units 1 and 2, Inservice Testing Program for pumps and valves whose function is safety-related.
PREFACE This report is supplied as part of the " Review of Pump and Valve Inservice Testing Programs for Operating Reactors (!!!)" and, " Review of Pump and Valve Inservice Testing Programs for Operating License Plants (II)"
programs being conducted for the U.S. ibelear Regulatory Commission, Office of Nuclear Reactor Regulation, Mechanical Engineering Branch, by EG&G Idaho, Inc., Regulatory and Technical Assistance.
FIN Nos. A6812 and A6811 B&R 920-19-05 02-0 Docket Nos. 50 317 and 50-318 i
TAC Nos. 56245 and 71889
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' 'J CONTENTS ABSTRACT.............................................................
11 PREFACE..............................................................
ii 1.
INTRODUCTION.....................................................
1 2.
PUMP TESTING PROGRAM.............................................
3 2.1 Multiple Pumps.............................................
3 2.1.1 Relief Request.....................................
3 2.1.2 Re l i e f Re q u e s t.....................................
5 3.
VALVE TESTING PROGRAM.............................................
9 3.1 Multipl(
- e. is...........................................
9 3.1.1 Lt
.sa t e Te s t i ng Val ve s............................
9 3.1.2 Excess Flow Check Valves............................
11 3.1.3 Rapid Acting Power Operated Valves..................
13 3.1.4 Series Check Valve Testing..........................
14 3.1.5 Series Parallel Check Valve Testing.................
18 3.2 Emergency Diesel Generators.................................
20 3.2.1 C a t e g o ry B V a l v e s...................................
20 3.3 Nuclear Boiler..............................................
22 3.3.1 Category A/C Valves.................................
22 3.3.2 Category B/C Valves.................................
23 3.3.3 Category C Valves...................................
25 3.4 Reactor Recirculation System...............................
29 3.4.1 C a t e g o ry A/ C - V a l v e s.................................
29 3.5 Cont rol Rod Dri ve - Part A..................................
31 3.5.1 Category B Valves...................................
31 3.6 Cont rol Rod Dri ve - Part B..................................
32 3.6.1 Category B Valves...................................
32 3.6.2 Category C Valves
........................e..........
33 3.7 Standby Liquid Control......................................
35 3.7.1 Category A/C Valves.................................
35 3.7.2 C a t e g o ry C V a l v e s...................................
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3.8 Reactor Core Isol ation Cooling............................. '.- 38 3.8.1 C a t e g o ry C V a l v e s...................................
38 3.9 Residual Heat Removal.......................................
40 3.9.1 Category B Valves...................................
40 3.10 Core Spray..................................................
41 3.10.1 C a t e g o ry A/ C V a l v e s.................................
41 3.11 High Pressure Coolant Injection.............................
43 3.11.1 Category C Valves...................................
43 3.12 Primary Containment Instrument Gas..........................
47 3.12.1 Category A/C Valves.................................
47 3.12.2 Category C Valves...................................
48 3.13 Control Structure Chilled Water.............................
49 3.13.1 C a t e g o ry B V a l v e s...................................
49 APPENDIX A -IST PROGRAM AN0MAllES IDENTIFIED DURING THE REVIEW......... A-1 i
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'i TECHNICAL EVALVATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM LIMERICK GENERATING STATION. UNITS 1 AND 2 1.
INTRODUCTION Contained herein is a technical evaluation of the pump and valve inservice testing (IST) program submitted by Philadelphia Electric Company for its Limerick Generating Station, Units 1 and 2.
By a letter dated July 21, 1987, Philadelphia Electric Company submitted Revision 6 of the Limerick Generating Station, Units 1 and 2, IST Program for the first ten year interval which commenced on February 1, 1986 for Unit 1 and January 8, 1990 for Unit 2.
A working meeting with NRC, EG&G Idaho, Philadelphia Electric Company, and Limerick Generating Station representatives was conducted February 24 and 25, 1988.
The licensee's IST Program, Revision 0, as revised by Philadelphia Electric Company, dated November 23, 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, 1986 Edition.
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."
l In their IST program, Philadelphia Electric Company has 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 Outde 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 tesi.ing requirements apply only to component l
testing (i.e., pumps and valves) and are not intended to provide the basis to-l change tne licensee's current Technical Specifications for system test requirements.
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Section 2 of this report presents the i.imerick Generating Station.
/l Units 1 and 2, relief requests and EG&G's evaluations and conclusions regarding these requests for the pump te uing program.
Similar information is presented in Section 3 for the valve testing program.
This TER, including all relief requests and component identification numbers, is applicable to Units 1 and 2.
Unit 2 pump and valve numbers are identified within parenthesis (2).
Inconsistencies and omissions in the licensee's program noted during the course of this review are listed in Appendix A.
The licensee should resolve these items in accordance with the evaluat, ions, conclusions, and guidelines presented in this report.
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2.
PUMP TESTING PROGRAM j
The Limerick Genercting Station, Units 1 and 2, IST program submitted by Philadelphia Electric Company was examined to verify that all pumps that are included in the program cre subjected to the periodic tests required by the ASME Code,Section XI, 1986 Edition, except for those pumps identified below for which specific relief from testing has been requested.
Each Philadelphia Electric Company basis for requesting relief from the pump testing requirements and the reviewer's evaluation of that request is sumarized below and grouped according to system.
2.1 Multiole Pumos 2.1.1 Measurement of Pumo Bearina Temoeratures 2.1.1.1 Relief Reauest.
The licensee has requested relief from the annual bearing temperature measurement requirements of Section XI, Paragraph IWP-3300, for the below listed pumps. The licensee has proposed monitoring bearing condition using the vibration monitoring program.
Pumo Number Descriotion OAP162 Control Room Chill Water Pumps OBP162 1AP256 Safeguard Piping Fill Pumps IBP256 2AP256 2BP256 1AP208 Standby Liquid Control Pumps IBP208 1CP208 2AP208 2BP208 2CP208 10P203 Reactor Core Isolation Cooling Pumps 20P203 10P204 High Pressure Coolant injection Pumps 20P204 i
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2.1.1.1.1 Licensee's Basis For Reauestina Relief--The measuring of l
bearing temperatures along with vibration monitoring are both means of determining the mechanical condition of a pump.
However, in order for l
bearing temperature measurements to be useful, continuous monitoring would be required.
The rise in temperature due to bearing degrad4 tion is a very sudden occurrence which is much more detectable in its early stages by utilizing vibration monitoring.
Serious degradation would have to occur to cause a detectable rise of temperature on the bearing housing.
Vibration monitoring is a more logical means of detecting bearing degradation prior to an increase in temperature.
Pump bearing mechanical condition will be determined using the vibration monitoring program.
Bearing temperature will not be measured.
2.1.1.1.2 Evaluation--There are many factors other than pump bearing condition that affect bearing temperature measurements such as the temperature of the pumped fluid, the bearing lubricant temperature, and the ambient temperature.
Fluctuations of these parameters could mask any change in bearing temperature due to degradation.
Industry experience has shown that during bearing degradation a significant temperature rise does not occur until just prior to and during catastrophic failure.
This makes the probability of detecting a degraded pump bearing using yearly bearing temperature measurements extremely small.
Experience has also shown that a pump vibratior monitoring program can detect bearing degradation early enough that correct'.ve actions can be taken thereby avoiding catastrophic bearing failure.
Cuarterly pump vibration measurements provide the ability to monitor pump mechanical condition and detect mechanical degradation 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.
2.1.2 Instrument Accuracy 2.1.2.1 Relief Reauest.
The licensee has requested relief from the instrumentation accuracy requirements of Section XI, Paragraph IWP-4110, for 4
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all pumps in the IST program with the exception of the safeguard piping fill, diesel fuel oil transfer, and standby liquid control pumps.
The licensee has proposed to use installed instruments which are accurate to i3% of full-scale range.
2.1.2.1.1 Licensee's Basis For Reauestino Relief -Various permanently installed pressure, flow and speed instrur. ants are accurate to 3% in lieu of the code required 2%,
Per the Code, full scale range of each instrument shall be three times the reference value or less.
The instrumentation involved fall into two categories.
(1) Where the 3% accuracy converts to an absolute accuracy equal to or better than the code required i2% accuracy.
For example, using a pressure reference value of 50 PSI and an actual full scale range of 100 psi:
(a)
C.q. ig (i.e., reference value - 50 psi 3 x reference value - 150 psi)
Instrument accuracy in units of pressure converts to:
12% x 150 psi - 23 psi (b)
Limeriel (i.e., full scale - 100 psi)
Instrument accuracy converts to:
3% x 100 psi = 23 psi As demonstrated in the example, if (b) is less than or equal to (a) then the existing instrumentation is considered to be sufficiently accurate.
(2) Where (lb) is greater than (la) but the difference is less than one increment (resolution) of the existing scale then the existing instrumentation is considered to be sufficiently accurate.
This is 5
based on the likelihood that two different people recording the
'I same reading can very well be off by one increment from each other on the same scale.
i.e., (la) = 100 psi (1b)= 175 psi Resolution 100 psi increments Since 175-100 + 75 psi is less than 100 psi, the existing instrument is considered to be sufficiently accurate.
Actual Examples:
(a) RCIC -F1-49-1R6001 (flow indicator)
Reference value - 560 gpm Full scale range = 0-700 gpm 2% x 3(560 gpm) - 33.6 gpm 3% x 700 gpm = 121.0 gpm Since the code required accuracy is more than the actual instrument error the flow indicator is considered to be sufficiently accurate.
(b) Core " pray - F1-521R601A (flow indicator)
Reference Value a 3400 gpm Full scale range = 0-8800 gpm Resolution = 200 gpm 2% x 3(3400 gpm) = r204 gpm 3% x 8800 gpm = i264 gpm Since the difference of 60 gpm is less than the resolution of 200 gpm the flow indicator is considered to be sufficiently accurate.
The existing pump instrumentation, which is accurate to 3%, is considered sufficiently accurate based on the reasons discussed above. No alternate testing will be performed.
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2.1.2.1.2 fn lgttiga--It is possible to use combinations of instrument accuracy and fuil scale range other than those required by Section XI and still be able to provide the same or bettw indication accuracy at the reference value as allowed by the Code.
Use of instrumentation that meets an indication accuracy of 16%.of the reference value, which corresponds to the indication accuracy obtained by multiplying the IWP-4110 accuracy requirement times the IWP 4120 allowable range requirement (12% accuracy times a range of up to 3 times the reference value), should be a reasonable al.ernative to the Code even though the Code accuracy all scale range requirements are not met.
Replacing the installeo instrumentation would result in hardship for the licensee due to the costs involved.
Fu ther, replacing instruments that yield accuracy, at the reference value, equivalent to that required by the Code would not provide a compensating increase in quality or safety.
The second category of instruments addressed by this relief request do not provide the same indication accuracy at reference values as required by the Code.
The licensee stated that these instruments would provide indication accuracy within one scale increment of the 16% accuracy permitted by the Code.
In example 2.b of the licensee's basis for relief, the installed instrument provides an indication accuracy of 7.8% at the reference value. Other instruments could feasibly have an indication accuracy as poor as i9% by the provisions of this relief request.
The licensee did not identify each affected pump instrument, the reference value, and the full scale range, trierefore, it is not possible to determine the l
available accuracies and the effect that use of these instruments would have on the licensee's ability to monitor pump hydraulic condition and detect degradation.
General relief cannot be granted for instrumentation that does not provide indication with equivalen' r.: curacy as required by the Code. To obtain such relief, it would be n:ce.sary to submit separate relief requests which provide the specific accuracies, reference values, and ranges along with a justification that demonstrates the adequacy of the installed instruments and identifies the burden of replacing them with instruments that meet the Code requirements.
Based on the determination that the proposed testing would provide l
reasonable assurance of operational readiness, and that compliance with the 7
Code requirements would result in hardship without a compensating increase in the level of quality or safety, relief may be granted for those instruments that provide the same or better indication accuracy at the reference value as required by the Code.
Since neither the actual indication accuracy nor the effect that their use will have on the licensee's ability to detect pump hydraulic degradation is knowc. relief should not be granted for those installed instruments that do not provide the same or better indication accuracy at the reference value as required by the Code.
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3.
VALVE TESTfNG PROGRAM The Limerick Generating Station, Units 1 and 2, IST program submitted by Philadelphia Electric Company was examined to verify that all valves included in the program are subjected to the periodic tests required by the ASME Code, 3ection XI, and the NRC positiois ani guidelines.
The reviewers found that, except as noted in tppendix A o: where specific relief from testing has been requested, these valves era tested to the Code requirements and NRC positions and guidelines.
Esch Pni!adelp m Electric Company basis for requesting relief from the valve testing rqu;*cments and the reviewer's evaluation of that request is summarized below and grouped according to system and valve Category. All relief requests and evaluations are applicable to both Units 1 and 2 unless otherwise noted.
3.1 General Valve Relief Recuests 3.1.1 leak Rate Testina Containment Isolation Valves 3.1.1.1 Relief Reauest.
The licensee has requested relief from the requirements of Section XI, Paragraph IWV-3420, to leak rate test Category A containment isolation valves.
The licensee has proposed leak rate testing these valves in accordance with 10 CFR 50, Appendix J, Type C, leak rate testing procedures during refueling outages.
3.1.1.1.1 Licensee's Basis For Recuestino Relief -Containment isolation valves are required to be leakage rate tested in accordance with 10 CFR 50, Appendix J.
The leakage rtte requirement is based on a total allowable leakage rate for all valves instead of an individual valve leakage rate.
IWV-2100(a) defines Category A as " valves for which seat leakage is limited to a specific maximum amount in the closed position of fulfillment of their function;"
Although for containment isolation valves leakage rates are not limited on an individual basis by Appendix J, they have been determined to be Category A valves.
S;nce containment isolation valves are Category A, the leakage rate testing requirements of IWV-3420 must be satisfied.
The leakage rate testing 9
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ll performed per Appendix J satisfies the requirements of IWY 3421 through -3425, however, it does not satisfy the individual valve leakage ' rate analysis and corrective actions of IWV-3426 and IWV-3427.
Appendix J testing is accomplished by performing individual local leak rate tests on each containment penetration.
The results of these tests represents the total leab ge from the boundary valves associated with the penetration.
In order to prevent duplicate leakage testing of these valves, a maximum permissible leakage will be established for each individual local leak rate test.
If this value is exceeded, then corrective action will be taken to restore the leakage rate to within acceptable limits.
The proposed actions will be taken in lieu of IWV-3426 and IWV-3427(a).
Double frequcncy testing, as required oy IWV-3427(b), shall not be performed.
The usefulness of the data does not justify tne burden of complying with this requirement.
Corrective action previously addressed will be sufficient in maintaining acceptable leakage rates, Containment isolation valves will be leak rate tested in accordance with t
the 10 CFR 50, Appendix J, Type C testing program.
In addition, a maximum permissible leakage criterion will be established for each individual local leak rate test.
If the local leak rate test leakage criterion is exceeded, corrective action will be taken to restore the leakage rate to within the acceptable value.
3.1.1.1.2 Evaluation--The licensee has proposed performing Appendix J, Type C, leak rate testing of all-containment isolation valves by penetration groups in lieu of the individual valve leak rate testing requirements of IWV 3420.
The leak test procedures and requirements for containment isolation valves identified in 10 CFR 50, Appendix J, incorporate all the major el,ements of Paragraphs IWV 3421 through -3425.
- However, 10 CFR 50, Appendix J, does not require trending of leakage rates or corrective actions based on individual valve leakage rates.
Where individual leakage limits can be assigned and valve leakage determined, the licensee should comply with the requirements of IWV-3426--and -3427(a).
Testing containment isolation valves in accordance with 10 CFR 50, Appendix J, and complying with-the Analysis of Leakage Rates and Corrective Action 10
5 Requirements.of Section XI, Paragraphs IWY 3426 and -3427(a), would provide l'
an acceptable level of quality and safety and would be an acceptable alternative to the Code requirements as addressed in NRC Generic letter No. 89 04, Attachment 1, item 10.
The piping configurations for some containment penetrations do not allow for the individual leak rate testing of the containment isolation valves that isolate the penetrations.
The only feasible method of verifying the leak-tight integrity of these valves is to leak rate test the penetration valves in groups.
For situations where there are multiple containment isolation valves branching from a coninon header, ascribing all leakage through the penetration to one valve could cause the performance of baseless maintenance on operable valves.
The licensee has stated that maximum leakage rates will be assigned to each valve group and if the measured leakage exceeds the assigned group limit, corrective actions will be taken as required by Paragraph IWV-3427.
This test method would providt an acceptable level of quality and safety if the assigned limiting leakage rate for each valve group is conservatively established regarding the number and sizes of valves in the group.
The assigned maximum group leakage rates should be l
based on the smallest valve in the group so that corrective actions are taken whenever the leak-tight integrity of any valve of that group is in question.
Based on the determination that 10 CFR 50, Appendix J, Type C leak rate testing would provide an acceptable level of quality and safety, relief may be granted from the requirements of IWV-3421 through -3425 and -3427(b).
For those valves that can only be tested in groups, relief from the individual-leak rate testing requirements of the Code may be granted provided the caigned maximum group leakage rates are based on the smallest valve in the group so that corrective actions are taken whenever the leak-tight integrity of any valve of that group is in question.
3.1.2 Excess Flow Check Valves 3.1.2.1 Relief Reouest.
The licensee has requested relief from the requirements of Section XI, Paragraph IWV-3520, to full-stroke exercise all excess flow check valves to the closed position quarterly or during cold 11
shutdowns. The licensee has proposed performing functional testing of the
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closure capability of these valves during refueling outages.
'l 3.1.2.1.1 Licensee's Basis For Reouestino Relief--Excess flow check valves are installed on instrument lines penetrating containment to minimize leakage in the event of an instrument line failure outside the containment in accordance with Regulatory Guide 1.11.
The excess flow check valve is basically a spring loaded check valve.
Since the system is normally in a static condition, the valve poppet is held open by the spring. Any sudden increase in flow through the valve (i.e., line break) will result in a differential pressure across the valve which will overcome the spring and close the valve.
Functional testing of valve closure is accomplished by venting the instrument side of the valve while the process side is under pressure, observing that the remote position indicator indicates closed and/or verifying the absence of leakage through the vent.
The testing described above requires the removal of the associated instrument or instruments from service.
Since these instruments are in use during plant operation and cold shutdown, removal of any of these instruments from service may cause a spurious signal which could result in a plant trip, an inadvertent initiation of a safety system, loss of decay heat removal and/or the defeating of safety interlocks.
In addition to the plant safety concerns, personnel safety concerns must be considered since the process side of these valves is normally high energy 0
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(>200 and >500 psig) and highly radioactive reactor coolant.
In summary, due to the plant and personnel safety concerns and plant operating conditions that prohibit the testing of these valves quarterly or at cold shutdown, testing will be performed at refueling when decay heat loads are at a minimum and safety systems can be removed from service to prevent inadvertent initiation.
3.1.2.1.2 Evaluation The excess flow check valves function to limit flow in case of an instrument line break outside containment.
Verification of valve closure capability rec,uires the isolation of instruments that are necessary for reactor protection and control.
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7 Performing this testing during power operation could inhibit safety system actuation or cause spurious system actuations which could result in a reactor trip.
Performing this testing during cold shutdowns could disrupt the operation of systems necessary for decay heat removal.
The licensee has proposed performing functional testing during refueling l
outages by venting the downstream side of the excess flow check valves and verifying (by position indication and/or limited leakage) that the valves have moved to the closed position.
The licensee's proposed testing would provide reasonable assurance that these valves are capable of performing their design function 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.
3.1.3 Raoid Actina Power Ooerated Valves 3.1.3.1 Relief Recuest.
The licensee has requested relief from the corrective action requirements of Section XI, Paragraph IWV-3417(a), for l
power operated valves that normally stroke in 2 seconds or less. The licensee has proposed assigning a maximum limiting stroke time of 2 seconds to these valves and taking corrective action in accordance with IWV-3417(b) l if the valve stroke times exceed the 2 second limit.
3.1.3.1.1 Licensee's Basis For Recuestina Relief -For rapid actuating power operated valves, the application of the Code requirements could result in increased testing when the valves are functioning normally.
These valves generally are small air and solenoid operated valves which, because of their size and actuator types, stroke very quickly. Operating history on tnis type of valve indicates that they generally either operate immediately or fail to operate.
The intent of the referenced testing requirement is to trend valve stroke time as a means of detecting valve degradation.
For rapid actuating power operated valves, comparison of stroke l
times to the previous stroke time is not an effective means of detecting 13
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valve degradation.
Because of the reasons mentioned above, rapid actuating
.y power operated valve stroke times will not be compared with the previous y
stroke times, but will be assigned a maximum limiting stroke time of 2 seconds.
A maximum limiting stroke time of 2 seconds will be specified for each rapid actuating power operated valve.
If the valve strokes in 2 seconds or less, it will be considered acceptable and no corrective action will be
- required, if the valve exceeds 2 seconds, appropriate corrective action will be taken.
3.1.3.1.2 Evaluation The NRC staff position on evaluating stroke times of rapid acting valves is explained in Generic Letter No. 89 04,. Position 6.
The licensee's proposed testing is in accordance with this position and would provide an t.cceptable 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.
3.1.4 Series Check Valve Testina 3.1.4.1 Relief Reauest.
The licensee has requested relief from the l
l exercising method requirements of Section XI, Paragraph IWV-3522, for the I
series sets of safeguards piping stay fill check valves listed below.
The licensee has proposed verifying the closure capability of each set of series check valves as a unit.
491(2)032 494(2)033 51-1(2)ll5A 51-1(2)116A 51 1(2)115C 51-1(2)l16C 52-1(2)045A 52-1(2)046A l
3.1.4.1.1 Licensee's Basis For Reauestino Relief--These check valves are installed in series and are not provided with a means to facilitate individual exercising.
There are no vents, drains, or test valves located between each pair of valves; therefore, no practical method exists to verify proper operation of the individual valves upon reversal of flow.
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fact that two valves are in series lessens the probability of failure to I,7 retard backflow.
In all cases of check valves in series, there is a means
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provided to verify proper valve operability of at least one of the two valves.
Each set of series check valves will be exercised quarterly, in the reverse direction, as a unit.
3.1.4.1.2 Evaluation--These are simple check valves without position indication.
There are no drain lines, vent lines, or test connections installed between these series valve pairs to individually verify the closure capability of each valve. These vn.lves can only be practically tested in pairs, which verifies that at least one of the two check valves is capable of closing, but provides no indication about the condition of the other valve.
Individual verification of each valve's closure capability would require significant system modifications which would be burdensome for the licensee due to the costs involved.
Since only one valve is required to actuate to perform the closed safety function, testing these series valves as a unit would demonstrate that the pair is capable of performing its intended design function.
The licensee's proposed alternative, to test each series pair of valves as a unit quartarly, j
would give reasonable assurance of operational readiness provided b~ th valves o
are repaired or replaced as necessary if excessivo leakage is detected.
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Based on the determination that compliance with the Code required l
testing is impractical, that the licensee's proposed alternative would l
provide reasonable assurance of operational readiness, and cons'idering the burden on the licensee if the Code requirements were imposed, relief may be granted provided both valves in the pair are declared inoperable and repaired or replaced if excessive leakage is detected during testing.
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3.1.4.2 Relief Reauest. The licensee has requested relief from the Y
exercising method and frequency requirements of Section XI, Paragraph IWV-3522, for the sets of series safeguards piping stay fill check valves listed below.
The licensee has proposed verifying the reverse flow closure capability of each check valve by disassembly during associated system mini outages or at refueling outages.
51-1(2)032A 51-1(1)032B 51-1(2)048A 55-1(2)048B 51 1(2)l15B 51 1(2)l150 55-1(2)F078 51-1(2)F090A 51-1(2)F0908 51 1(2)F090C SI-1(2)F0900 521(2)045B 52-1(2)f030A 52-1(2)F030B 3.1.4.2.1 Licensee's Basis For Reauestino Relief--The above valves function as the safeguard piping stay fill or condensate transfer stay fill check valves.
Because of system configuration, these valves cannot be verified closed using visual verification, system parameters or by leak testing methods.
Valve disassembly will be required to verify reverse direction closure.
Disassembly of the valves, if attempted at cold shutdown, could result in a delayed plant startup.
Condensate transfer stay fill check valves will be verified to operate in the reverse direction during refueling or associated system mini outages by valve disassembly.
Safeguard piping stay fill check valves will be verified to operate in the reverse direction during refueling or Safeguard Piping Fill System mini outages by valve disassembly.
3.1.4.2.2 Evaluation -These are simple check valves that are normally open to allow the flow of water from the safeguard piping stay fill or condensate transfer pumps to maintain the ECCS system piping water solid.
These valves do not have position indication or any other external means of determining the obturator position.
In each case the listed valves are one of two check valves installed in series in the stay fill lines.
There are no pressure instruments installed in the upstream lines.
Also, there are no l
test connections in:talled in the lines either between the series valves or upstream of the valve pairs.
Verifying the closure capability of these valves by leak testing would require system modifications that would be burdensome for the licensee due to the costs involved.
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A The Minutes of the Public Meeting on Generic Letter No. 89 04 state that
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~ the use of disassembly to verify closure Japability may be acceptable l
depending on whether verification by flow or pressure measurements is practical.
These Minutes also state that exercising 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 provide reasonable assurance of operational readiness.
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 uader the maintenance program at a frequency comensurate 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 leak rate testing or 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 le:k testing or observation of system parameters, that the licensee's proposed alternative would provide reasonable assurance of operational readiness, and considering the burden on the licensee if the Code requirements were imposed, relief ray be granted provided the licensee full or part-stroke exercises these valves open with flow af ter they have been reassembled.
The licensee should investigate ways, other than disassembly and inspection, of verifying the reverse flow closure capability of these valves.
If another method is developed to verify the l
closure capability of these check valves, this relief request should be revised or withdrawn.
l l
17
g 3.1.5 Series Parallel Check Valve Testing l
3.1.5.1 Relief Reauest.
The licensee has requested relief from the exercising method requirements of Section XI, Paragraph IWV-3522, for the fonowing vacuum relief check valves.
The licensee has proposed full-stroke exercising each set of four series-parallel check valves as a unit.
49 1(2)017 491(2)018 491(2)F068 49-1(2)F081 55 1(2)025 55-1(2)026 55-1(2)F080 55-1(2)F094 3.1.5.1.1 Licensee's Basis For Reauestino Relief--These check valves, that function as vacuum relief valves, are installed in series parallel and were not provided with air operators to facilitate testing (exercising).
The piping configurations in the High Pressure Coolant Injection and Reactor Core Isolation Cooling systems do not allow for individual testing of these valves.
Since a series parallel arrangement was used, there are multiple combinations of flow paths any one of which would provide vacuum relief.
No single valve failure would prevent the system from providing vacuum relief.
Because single valve failure will not prevent the system from functioning as designed, and system configuration does not allow for individual valve testing, testing as a unit will verify the system can provide vacuum relief as designed.
Vacuum relief valves will be tested quarterly, in the forward direction, as a unit.
3.1.5.1.2 Evaluation--These check valves perform a vacuum breaker function to prevent suppression pool water from being drawn into the High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) turbine exhaust lines during cooldown after turbine operation.
These valves also perform a safety function in the closed position to prevent exhaust steam from entering the wet-well air space.
With the series-parallel configuration, the existing test taps, and lack of isolation valves, it is not practicable to individually verify that these valves move to the open position during any plant mode.
The licensee's proposed testing would verify that these valves are capable of performing 18
g, T
their design function in the open position by demonstrating that the valves, as a unit, are capable of passing the flow necessary to prevent drawing a vacuum in the turbine steam exhaust lines after operation of the HPCI and RCIC turbines. However, group testing gives no indication of individual valve condition. A failed valve could remain undetected for extended periods and may not be discovered until a second failure occurs.
Since two failures must occur prior to detection by group testing, repairing only one valve is not acceptable.
When the group fails to permit the required forward flow, all valves in the group are suspect and should be declared inoperable until they are repaired, replaced, or individually verified capable of performing their safety function.
The licensee's proposed alternative, combined with the above corrective action requirements would provide reasonable assurance of operational readiness.
it would be necessary to make system modifications to permit verifying the full stroke open capability of each check valve with flow.- Due to the costs involved, it would be burdensome to require the licensee to modify this design, which affords a great deal of opzrational reliability.
In response to a request for additional information from the NRC staff, the licensee stated that valve closure is verified by a temperature sensor'in the upstream line that provides an alarm in the main control room if reverse flow was allowed by the combined failure of one check valve in each parallel pair.
For this series-parallel arrangement, this test verifies that at least one of the parallel valve combinations is closed, but it does not provide information about the condition of the remaining valve combination.
One valve, or a pair of parallel valves could be failed in the open position and could go undetected.
Adequate isolation valves and test taps are available to leak test each parallel valve combination to-verify that each individual valve is capable of preventing reverse flow, lherefore, since the Code requirements for verifying the closure capability of each valve can be met, the licensee is expected to comply with this Code requirement.
Based on the determination that compliance with the Code exercising method requirement for valve opening is impractical, that the licensee's proposed alterrative would provide reasonable assurance of operational 19
1 l
readiness, and considering the burden on the licensee if Code requirements cere imposed, relief may be granted provided all valves are disassembled and X
repaired or replaced as necessary if the opening capability of any of these Y
valves is questionable.
3.2 Emeroency Diesel Genefa. tar 3 3.2.1 Cateoorv B Valves 3.2.1.1 Relief Recuest.
The licensee has requested relief from the exercising and stroke time measurement requirements of Section XI. Paragraphs IWV 3412 and 3413, for the following diesel generator air start solenoid valves.
The licensee has proposed testing these valves as a unit during the monthly diesel testing and to alternatcly isolate the air headers during diesel testing every 18 months.
92-1(2)302A 92-1(2)302B 92-1(2)302C 92-1(2)3020 92 1(2)303A 92-1(2)303B 92-1(2)303C 92 1(2)3030 92 1(2)308A 92-1(2)3088 92-1(2)308C 92-1(2)3080 92-1(2)309A 92-1(?)300S 92-1(2)309C 92-1(2)3090 3.2.1.1.1 Licensee's Basis For Recuestino Relief -These valves are non ASME but are in air starting lines that are designed to ASME III Class-3 requirements.
The valves vere not provided with any position indication; therefore, stroke timing by local or remote position indication is not possible.
Ognificant degradation or failure of these valves to operate would however, be indicated by an increased starting time on the Emergency Diesel Generator or its failure to start.
Because it is not possible to measure individual valve stroke times, Emergency Diesel Generator starting times will be measured ir its stead.
Alternate isolation of the air start headers, to verify individual va've performance, requires complex valve manipulations and de-onergizing of a portion of the engine control logic, both of which increases the probability of a testing induced failure.
Therefore, alternate isolation of the air start headers will be performed every 18 months.
This interval is consistent with the recommendations of INP0 50ER #80-1 " Loss of Redundant Emergency Diesel Generator Start Air System."
20
T In lieu of the individual valve exercise testing required by IWV 3413, 4
failure of the Emergency Diesel Generator to start, during monthly testing will be evaluated to determine if the cause can be attributed to the associated starting air valves. Alternate isolation ~ of the air headers every 18 months, during the emergency Diesel Generator testing required by Technical Specifications, will verify individual performance of these valves.
Valve 4
stroke time testing will not be performed.
3.2.1.1.2 Evaluation-Stroke timing these rapid-acting solenoid valves using conventional techniques is not practical because they are not equipped with position indication and valve' stem movement cannot be observed.
These valves could be tasted to the Code requirements only after si;;nificant redesign and modif(cations to the control circuitry for these valves, such es 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.
The ciesel generator air start system is designed with redundant air-start valves and headers. One air start train is capable of successfully starting the diesel generator.
The licensee has proposed measuring diesel start times during monthly testing using both air start trains and alternately isolating the air headers to verify individual valve operability once every 18 montht.
However, the monthly testing would not adequately demonstrate the operability of all air start valves.
The valves in one train could be degraded for extended periods without detection and correction.
The licensee has not provided an adequate justification for not isolating one air start train to verify operability of the valves in the other train-on a quarterly basis.
Piping and Instrument Drawing lSI-M 20 shows manual valves that could possibly be used to isolate an air start train during diesel testing to verify operability of the other train.
Sine.e valve degradation would be evidenced by increased diesel starting time, measuring the diesel start time, assigning a maximum limiting start time, and verifying the operability of the ulves in 21 i
-.. - = _
y each air start train at least quarterly should provide an indication of degradation and reasonable assurance of operktional readiness.
This maxinn start time should be less than or equd to the Technical Specification requirement.
Based on the deter,.anation that compliance with the Code requirements is impractical, and consider 1g the burden on the licensee if.the Code requirements were imposed, relief may be granted provided the licensee assigns a maximum limiting diesel start time which is less than or cqual to the Technical Specification limit and verifies the operability of the valve 4 each air start train at least quarterly by isolating one air start train on an alternating basis during diesel testing.
3.3 Nuclear Boiler
'3. 3.1 Cateoorv A/C Valves 3.3.1.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IW-3520, for the feedwater system inside containment isolation valves, 41-1(2)F010A and B, to the closed position.
The licensee has proposed verifying the closure capability of these valves using Appendix J, Type C, leak rate testing dwing i
refueling outages.
3.3.1.1.1 Licensee's Basis For Roouestino Relief--Verification of reverse flow closcre of these valves is accomplished by leak testing.
Since these valves are containment isolation valves, they are leak tested during Appendix J, Type C testing at refueling.
In order to perform leak testing manual valves located inside primary containment must be opened and temporary test equipment installed.
During power operation and normally 'at cold shutdown, the primary containment atmosphere is inerted with nitrogen, limiting access to emergencies only.
Because leak testing at' power is not possible, and is impractical at cold shutdown due to the probability of-delaying plant startup, these valves will be leak tested at refueling.
Reverse flow closure will be verified during Appendix J, Type C testing during refueling.
l i
22 i
4
- 3. 3.1. L Z Evaluation These valves are containunt isolation check valves located inside containment and are, therefore, inaccessibis during reactor operation.
The only method available to verify valve closure is leak rate testing which would require a containment entry.
These check velves are located in the main feedwater flow path to the reactor vessel and testing them closed during power operation is impractical since it would necessitate isolating a main feedwater header which could result in loss of reactor vessel level control and a reactor trip.
- Further, during power operation the containment atmosphere is maintained with a high concentration of inert gas which reduces the oxygen level sufficiently to make entry a personnel hazard.
Leak testing during cold shutdowns is impractical since the containment is often maintained inerted.
This testing would require a significant amount of time for test equipment setup, test perfort...nce, 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.
Verifying the reverse flow closure of these valves using Appendix J Type C, leak rate testing during refueling outages would provide reasonable assurance of operational readiness.
l l
Based on the determination that it is impractical to verify the closure capability of thest valves quarterly or during cold shutdowns, that the proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3.? [.Ltr pry B/C Valves 3.3.2.1 Relief Recuest.
The licensee has requested relief from the exercising frequency and stroke. timing requirements of Section XI, hr: graphs !WV 3411 and 3413, for the reactor coolant system automatic depressurization syetem (ADS) valves, PSV 41 1(2)F013E, H K, M, and S.
The licensee has proposed full stroke exercising these valves at restart after refueling outages with no stroke timing.
23
-~
3.3.2.1.1 Licensee's Basis For Reauestino Relief !f any of these f
valves fail to reclose after testing, the piant would be placed in a Loss of -
t' Coolant Accident (LOCA) condition requiring plant shutdown in accordance with Technical Specification 3.4.2.b.
In addition, a recent study (BWR Owner's Group Evaluation of NUREG 0737, Item !!.K.3.16. Reduction of Challenges and Failures of Relief Valves) recommends that the number of ' ADS opening be reduced as much as possible. Based on this study and the potential for causing a LOCA condition, exercise testing of the ADS valves will be delayed to restart after refueling.
Stroke time on these valves cannot be accurately determined since the control room positto
'ndication only indicates if the solenoid valve is energized, and not tne actual valve disc position.
The only way possible to determine the opening of the relief valve is by acoustics monitoring of the SRV line discharge to the torus.
Measuring the time from the initiation signal for the valve and the acoustic monitoring detection does not provide meaningful data for predicting valve degradation.
3.3.2.1.2 Evaluation The ADS valves act both as power operated valves, in response to a manual or automatic control signal, and as safety relief valves.
As a result, these valves should be tested to both the Category B and C requirements.
Full stroke exercising these valves quarterly during power operation is impractical as tnis greatly increases the risk of creating a small break LOCA.
NUREG 0626 " Generic Evaluation of Feedwater Transients and Small Break Loss of Coolant Accidents in GC Designed Operating Plants and Near Term Operating License Applications," and NUREG 0737 Section ll.K.3.16, " Reduction of Challenges and failures of Relief Valves,'
recommend the reduction of challenges to relief valves to lessen the risk of a small break LOCA. Also, opening these valves during power operation would cause reactor pressure and power fluctuations that could lead to a reactor trip.
Full stroke exercising these valves requires reactor staan pressure and is not practical during cold shutdowns when the reactor pressure is low.
These valves are not equipped with direct sensing valve position indication and have extremely short stroke times that are dependent on steam pressure.
Obtaining trendable stroke times using acoustic monitoring of 24
S
's
' the discharge is not practical since this indirect indicatien of valve position would not yield measurements that are sufficiently repeatable.
Trending of valve stroke times would not be meaningful since response times and test pressure variations could mask changes in valve condition.
Significant system design changes would be necessary to enable valve exercising and stroke time trending quarterly or during cold shutdowns. Those modifications would be burdensome for the licensee due to the costs involved.
The licensee's proposal to exercise these valves during refueling outages would demonstrate their ability to perform their safety function.
However, to monitor for valve degradation, the licensee should assign a maximum stroke time limit to these valves that is based on previous test data and verify that they stroke within that limit during testing.
The measured stroke times need not be trended or compared to previous values, but if the maximum limit is exceeded, the valve should be declared inoperable and corrective action taken in accordance with IWV-3417(b).
The licensee's proposed testing during refueling outages combined with verification that va,ve stroke times are less than the maximum limiting value would provide reasonable assurance of operational readiness.
Based on the determination that compliance with the Code exercising frequency and stroke time trending requirements is impractical, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted provided tra licensee measures the valve stroke times as discussed above.
3.3.3 Cateaory C Valves 3.3.3.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI, paragraph IWV 3522, for the ADS valve actuator accumulator gas supply check valves, 41 1(2)F036E, H. K. M, and S quarterly or during cold shutdowns.
The licensee has proposed full stroke exercising these check valves during those cold shutdowns when containment is de inerted and during refueling outages.
l 25
~.--,-n+-m,n-,.-----,-,,,.,,,a
., ~,...,., -..
,,,,,,,,,.,a
.,..,,,.-,,..,,v, nn,
3.3.3.1.1 Licensee's Basis For Recues'in Relief Verification of
- f t
reverse exercising requires isolating the associated instrument gas header and venting the upstream side through a test connection located inside primary containment.
To verify forward exercising requires lowering the pressure in the associated ADS accumulator with the gas supply isolated, then opening the gas supply and observing that ADS accumulator pressure increases.
Since installed pressure indication is not provided for the ADS accumulators, a temporary test gauge must,be installed on a pressure tap located inside the primary containment.
During power operation and cold shutdown, the containment atmosphere is normally inerted with nitrogen limiting access to l
emergencies only.
In addition, high radiation levels during power operation prohibit containment entry.
i Forward and reverse exercising will be verified daring all rafueling outages and during cold shutdowns when the primary containment is de inerted.
3.3.3.1.2 Evaluation -These are simple check valves that do not have position indication or any other external means of determining the obturator position.
It would be necessary to manually vent off the accumulators to exercise these valves open without cycling the ADS valves.
The only practical method of verifying valve closure is to perform a leak test or pressure decay test, which requires isolating and venting off the supply header.
It is not practical to perform either test quarterly during power operation because it would require a containment entry and the containment atmosphere is maintained oxygen deficient with a high concentration of inrt
- gas, t
During cold shutdowns the containment is often maintained inerted which makes entry impractical to permit exercising these valves to either the open or the closed position.
it would be burdensome to require the licensee to de inert the containment each cold shutdown sclely to perform valve testing since this is costly and could result in a delay in reactor startup from cold shutdown.
The licensee's proposal to exercise these valves both open and closed during refueling
- tages and those cold shutdowns when the containment is de-inerted, would provide reasonable assurance of valve operational readiness.
26
Based on the determination that it is impractical to fullostroke exercise these check valves cuarterly or during each cold shutdown, that the g
licensee's proposed testing would provide a reasonable alterrative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3.3.2 Relief Reouest. The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV 3522, for the inboardmainsteamisolationvalve(MSIV)accumulatorinletcheckvalves, 41 1(2)F024A, B, C, and D.
The licensee has proposed full stroke exercising these check valves during refueling outages and during those cold :hutdowns when the containment is de inerted.
3.3.3.2.1 Licensee's Basis For Reauestino Relief-Verification of
(
reverse exercising requires isolating the associated instrument nitrogen header, venting the upstream side of the check valve and observing accumulator pressure.
These valves are located inside the primary containment and testing requires entering the containment for the installation of a temporary pressure gauge and to vent the upstream piping.
During power operation and cold shutdown, the containment atmosphere is normally inerted with nitrogen limiting access to emergencies only.
In addition, high radiation levell < luring power operation prohibit containment entry.
Reverse exercising will be verified during all refueling outages and during cold shutdowns when the primary containment is de inerted.
3.3.3.2.2 Evaluation These are simple check valves that do not have position indicatio: 3r any other external means of determining the obturator position.
These valves provide gas to keep the inboard MSIV accumulators charged.
The only practical method of verifying valve closure is to perform a leak test or pressure decay test, which requires isolating and venting off the supply header and observing the pressure downstream of these valves.
It is not practical to perform this testing quarterly during power operation because it would require a containment entry and the containment atmosphere is maintained oxygen deficient with a high concentration of inert gas.
27 f
i
During cold shutdocns the containment is often maintained inerted which makes entry to exercise these valves to the closed position impractical.
It
.g would be burdensome to require the licensee to de inert the containment each cold shutdown solely to perform valve testing since this is costly and could result in a delay in reactor startup from cold shutdown.
The licensee's proposal to exercise these valves during refueling outages and those cold shutdowns when the containment is de inerted, would provide reasonable assurance of valve operational readiness.
Based on the determination that it is impractical to full-stroke exercise these check valves quarterly or during each cold shutdown, that the licensee's proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3.3.3 Relief Recuest.
The licensee has requested relief from the exercising frequency requirements of Section XI, Partgraph IW 3522, for the outboard MSIV accumulator inlet check valves, 41 lF02gA, 8. C, and D.
The licensee has proposed full stroke exercising these check valves during refueling outages.
3.3.3.3.1 Licensee's Basis For Recuestino Relief System configuration does not provide the necessary test connections to perform the required testing.
Therefore, testing must be performed by disassembling mechanical connections and installing the necessary test equipment.
During normal operation this method would require a reduction in power and closing the associated MSIV.
In addition, these valves are tocated in a high temperature and high radiation area. At cold snutdown the method of testing could result in a delay in plant restart.
These valves will be full stroke exercised in the reverse direction at refueling.
3.3.3.3.2 Evaluation These are simple check valves that do not have position indication or any other external means of determining the obturator position.
These valves provide gas to keep the inboard MSIV accumulators charged.
The only practical method of verifying valve closure is to perform a leak test or pressure decay test.
Performing this testing 28
requires partially disassembling the gas supply line and a significant amount
'l
- of time for test equipment setup, test performance, and test equipment removal.
It is impractical to verify the reverse flow closure of these i
valves quarterly during power operation because it could result in MSIV closure and a plant trip.
This testing could be practicably performed each quarter only after system design changes.
Performing this testing during cold shutdowns could result in a delay of plant startup.
These delays, and the design changes necessary to enable testing quarterly during power operation, would be burdensome for the licensee due to the costs involved.
The licensee's proposal to exercise these valves during refueling outages would provide reasonable assurance of valve operational readiness.
Based on the determination that compliance with the Code exercising frequency requirements is impractical, that tne licensee's proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.4 Reactor Recirculation System 3.4.1 Cateoory A/C Valves 3.4.1.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IW 3520, for the recirculation pump seal purge primary containment isolation check valves, 43 1(2)004A and B.
The licensee has proposed full-stroke exercising these check valves closed using Appendix J. Type C, leak rate testing during refueling outages.
3.4.1.1.1 Licensee's Basis for Recuestina Relief-These check valves are located inside primary containment in the reactor recirculation pump seal purge supply lines and are open during power operation.
Exercising the valves to the closed position during operation would require interruption of seal purge water flow to the reactor recirculation pumps.
Due to system i
configuration the most practical method to verify reverse flow closure of l
these valves is by leak testing.
In order to leak test the valves, manual l
29
h valves located inside the primary containment must be opened.
During power operation and cold shutdown, the containment atmosphere is normally inerted with nitrogen, limiting access to emergencies only.
Leak testing at power is not possible and is impractical at cold shutdown, when containment is de inerted, by possible delaying plant startup.
No part stroke will be performed.
1hese valves will be tested in the reverse direction at refueling during Appendix J. Type C testing.
3.4.1.1.2 Evaluation These valves are containment isolation check valves located inside containment and are, therefore, inaccessible during reactor operation.
The only method available to verify valve closure is leak rate testing which would require a containment entry.
During power operation the containment atmosphere is maintained with a high concentration of inert gas which reduces the oxygen level sufficiently to make entry a personnel hazard.
Leak testing during cold shutdowns is impractical since the containment is often maintained inerted.
Further, this testing would require a significant amount of time for test ec,uipment setup, test performance, and test equipment removal and could resuit 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.
Verifying the reverse flow closure capability of these valves using Appendix J. Type C, leak rate testing during refueling outages would provide reasonable assurance of operational readiness.
Based on the determination that compliance with the Code exercising requirements is impractical, that the licensee's proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
30
3.5 Control Rod Drive - Part A 3.5.1 Cateoory B Valves l
3.5.1,1 Relief Recuest.
The licensee has requested relief from the j
exercising frequency requirements of Section XI, Paragraph IWV 3412, for the reactor recirculation pumps seal purge water line bypass leakage vent valves, HV 46 1(2)25 and 1(2)26.
The licenite has proposed full stroke exercising these valves during cold shutdowns when the containment is de inerted and each refueling outane.
3.5.1.1.1 Licensee's Basis For Reesestino Relief-The above valves serve as the recirculation pumps seal purge water line bypass leakage vent valves.
Exercising these valves during operation could result in air reaching the seal water cavity causing damage to the seal.
Piping configuration does not allow a means of venting this air except by entering the containment.
During operation and cold shutdown the containment is a high radiation area and is inerted with nitrogen prohibiting entry.
No part stroke will be performed.
These valves will be full stroke l
exercised and stroke timed during refuelings or at cold shutdowns when l
containment is de inerted.
3.5.1.1.2 Evaluation It is impractical to exercise these valves quarterly during power operation because this testing could result in damage to the pump seals.
Further, the containment is maintained inerted during power operation and during most cold shutdowns.
Exercising these valve.;
l requires ventir.g of the associated piping, which can be performed only from inside the containment.
Exercising those valves quarterly during power i
operation would require the reactor to be shutdown and the containment de inerted.
Exercising these valves every cold shutdown woulti also require de inerting of the containment.
Shutting down the reactor and/or de inerting the containment to enable testing at the Code required frequency would be burdensome for the licensee due to the costs involved.
31
.= -.
The licensee's proposal, to full stroke exercise these valves during I
cold shutdowns when the containment is de inerted and during refueling outages would provide reasonable assurance of operation 61 readiness and would be a reasonable alternative to the Code requirements.
Based on the determination that compliance with the Code exercising frequency requirements is impractical, that the licensee's proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.6 Control Rod Drive Hydraulic Part B 3.6.1 Cateoory B Valves 3.6.1.1 Relief Recuest.
The licensee has requested relief from the exercising frequency and method requirements and valve stroke timing requirements of Section XI, Paragraphs IW 3412 and.3413, respectively, for the control rod drive scram valves, XV 471(2) 26 and 1(2) 27 (one valve pair for each of the 185 hydraulic control units).
The licensee has proposed verifying the operability of these valves using control rod scram insertion time testing, per Technical Specification 4.1.3.2.
3.6.1.1.1 Licensee's Basis For Recuestino Relief These valves are located on the hydraulic control units (HCUs) for the control rod drives.
l The air operated valves, XV 471(2) 26 and -27, open on a signal from the reactor protection system to permit rapid insertion of the control rods (scram).
System configuration does not permit individual testing of these valves or stroke timing of the Category B valves.
However, the proper function of these valves as a unit is verified by performing a scram test on their associated control rod and verifying rod insertion times.
Technical Specifications require periodic scram testing of each control rod at an interval adequate to determine that the valves and control rod *.re operable and not so frequent as to cause excessive wear on the system components.
32
The control rod scran insertion time testing required by Technical Specification 4.1.3.2 will be performed in Iteu of the Section XI testing.
With reactor coolant pressure 1950 psig and the rod drive pumps isolated from the accumulators, maximum scram insertion times shall be demon.trated:
For all control rods prior to thermal power exceedtog 40% of rated a.
thermal power following core alterations or after a reactor shutdown that is greater than 120 days, b.
For specifically affected individual control rods following maintenance on or modification to the control rod or control rod drive system which could affect the scram insertion time of those specific control rods.
For at least 10% of the control rods, on a rotating basis, at c.
least once per 120 days of power operation.
3.6.1.1.2 Evaluatjan These valves cannot be exercised without causing the associated control rod to scram.
The NRC staff position on testing individual control rod scram valves in Boiling Water Reactors is explained in Generic letter No. 89 04, Attachme t 1, Position 7.
The licensee's proposal, to scram test the control rods and measure the control rod insertion times per plant Technical Specifications in lieu of the Code exercising and stroke timing requirements is in accordance with this position and provides an acceptable level of quality and safety.
Based on the determination that the licensee's proposed alternate testing provides an acceptable level of quality and safety, relief may be I
granted as requested.
3.6.2 Cateoorv C Valves 3.6.2.1 Relief Reauest.
The licensee has requested relief from the exercising frequency and method requirements of Section XI, I
paragraph IWV 3520, for the control rod drive scram check valves, 471(2)14 (one valve for each of the 185 hydraulic control units). The licensee has l
proposed verifying the full-stroke capability of these check valves-by I
performing control rod scram insertion time testing per plant Technical Specification 4.1.3.2.
33
?
.-.m.
_ _ _ _.... _, _.~.
,_,....__,__....,,.___.___,...m_,.m
._r, w...
~_... m,+ m
,..s.
3.6.2.1.1 Licensee's Basis For Raouestina Relief.These valves are l'
located on the hydraulic control units (HCUs) for the control rod drives.
The air operated valves, XV 47 1(2) 26 and 27, open on a signal from the reactor protection system to permit rapid insertion of the control rods (scram).
Check valve, 471(2)14 is flow actuated as a r,esult of XV 47 1(2) 27 opening.
System configuration does not permit individual testing of these valves.
However, the proper function of these valves as a unit is verified by performing a scram test on their associated control rod and verifying rod insertion times.
Technical Specifications require periodic scram testing of each control rod at an interval adequate to determine that the valves and control rod are operable and not so frequent as to cause excessive wear on the system components.
The control rod scram insertion time testing required by Technical Specification 4.1.3.2 will be performed in 1 eu of the Section XI testing.
With reactor coolant pressure 2 950 psig anj the rod drive pumps isolated from the accumulators, maximum scram insertion times shall be demonstrated:
a.
For all control rods prior to thermal power exceeding 40% of rated thermal power following core alterations or after, reactor shutdown that is greater than 120 days, b.
For specifically affected individual control roo; following maintenance on or modification to the control rod or control rod drive system which could affect the scram insertW time of those specific control rods.
c.
For at least 10% of the control rods, on a rotating basis, at least once per 120 days of power operation.
3.6.2.1.2 Evaluation -The 14 valve, which is located in the scram discharge line, must open to allow the control rod to scram and proper operation is verified during control rod scram testing if the associated control rod meets the scram insertion time limits defined in the Technical Specifications.
The NRC staff position on testing individual control rod scram valves in Boiling Water Reactors is explained in Generic letter No. 89 04, Attachment 1, Position 7.
The licensee's proposal, to scram test the control rods and measure the control rod insertion times per plant Technical Specifications in lieu of the Code exercising and stroke timing 34 x
7 y
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r.
_ _ _ ~. _ _.
requirements is in accordance Dith this position and provides an acceptable level of quality and safety, j
e Based on the determination that the licensee's proposed alternate testing provides an acceptable level of quality ard safety, relief may be granted as requested, l
1 3.7 Standby Liouid Control 3.7.1 Catenerv A/C Valves 3.7.1.1 Relief Reauest.
The licenae has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV 3520, for the standby liquid control (SLC) injection line primary containment isolation check valves HV 48 1(2)F006A, 1(2)F0068, and 1(2)f007.
The licensee has proposed full stroke exercising these check valves each refueling during the SLC system injection test.
3.7.1.1.1 Licensee's Basis For Recuestino Relief Verifying forward flow operability requires firing a squib valve and injecting water into the reactor coolant systsm (RCS) using the standby liquid control (SLC) pumps.
The frequent introduction of relatively colder water into the Reactor Coolant Systen, associated with this type of testing, would result in an excessive number of thermai cycles to SLC piping and components.
Additionally, the introduction of colder water would increase reactivity due to the colder moderator temperature.
Since the firirig of a squib valve requires valve disassembly to replace internals, firing should be minimized.
Therefore, forward flow testing of the check valves will be performed during SLC injection testing as required by Technical Specifications 4.1.5.d.l.
Due to system configuration the most practical method to verify reverse flow-closure on 481(2)F007 is by leak testing.
In order to leak test, I
f temporary test equipment must be installed inside primary containment.
During power operation and normally at cold shutdown, the primary containment 35
-~
I atmosphere is inerted with nitrogen, limiting access to emergencies only.
Because leak testing at power is not possible, and is impractical at cold shutdown, by possibly delaying plant startup, this valve will be tested in the reverse direction at refueling during Appendix J, Type C testing.
forward flow operability will be verified at refueling during SLC injection testing.
Reverse flow closure for 481(2)f007 will be verified at refueling during Appendix J Type C testing.
3.7.1.1.2 Evaluation Verifying the full stroke open capability of thne check valves with flow requires firing an explosive actuated valve and could result in the injection of boron solution into the RCS using the SLC pumps.
It is impractical to perform this testing quarterly during power operation because the injection of relatively cold boron solution would result in thermal cycles to SLC and RCS compoN nts, and reactivity transients that could cause a reactor shutdown.
Additionally, the explosive valves must have their internals replaced after fir kg.
Since this testing requires injecting concentrated boron solution int'., the reactor coolant system and replacement of explosive actuated valve internals after testing, exercising these valves to the open position with flow t.uring cold shutdowns could result in a delay in the return to power.
System modifications would be necessary to enable the quarterly performance of this testing.
The cost of these modifications and the possible costs due to delays in plant startup would be burdensome for the licensee.
The licensee's proposed alternative, to full stroke exercise these valves during SLC injection testing each refueling outage would provide l
reasonable assurance of operational readiness.
Checkvalve481(2)F007doesnothaveremotepositionindicationand I
the only practical method of verifying valve closure is leak testing.
This valve is located inside the containment and is inaccessible during power operation.
Leak testing during cold shutdowns is impractical since the containment is often maintained inerted.
This testing would require a l
significant amour.t of time for test equipment setup, test performance, and l
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 36
- a to the costs involved.
Verifying the reverse flow closure of this valve
. using Appendix J Type C, leak rate testing during refueling outages would provide reasonable assurance of operational readiness.
Based on the determination that compliance with the Code required testing is in. practical, that the licensee's proposed testin( would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.7.2 Cateaerv C Valves 3.7.2.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV4220. for the SLC inboard injection check valve, 48 1(2)027.
The licensee has proposed full stroke exercising this check valve each refueling during the SLC injection test.
3.7.2.1.1 Licensee's Basis For Reauestina Relief Verifying forward flow operability requires firing a squib valve and injecting water into the reactor coolant system using the standby liquid control pumps.
The frequent introduction of relatively colder water into the reactor coolant syster associated with this type of testing, would result in an excessive numbe of thermal cycles to SLC piping and components. Additionally, the in6roduction of colder water would increase reactivity due to the colder moderator temperature.
Since the firing of a squib valve requires valve disassembly to replace internals, firing should be minimized.
Therefore, forward flow testing of the check valve will be performed during SLC injection testing as required by Technical Specification 4.1.5.d.l.
3.7.2.1.2 Evaluation -Verifying the full stroke open capability of this check valve with flow requires firing an explosive actuated valve and could result in the injection of boron solution into the RCS using the SLC pumps.
It is impractical to perform this testing Quarterly during power l
l 37 e
y ew egg
- s !-;RMMy.
%f:'
u operation because the injection of relatively cold boron solution would result j in thermal cycles to SLC and RCS components, and reactivity transients that D%7
~
could cause a reactor shutdown. Additionally, the explosive vilves must have DS their internals replaced after firing.. Sincethistestingrequiresinjectingy g t
L concentrated boron solution into the reactor coolant system andfeplacement~cf;hg explosive actuated valve internals after testing, exercisin, open position with flow during cold shutdowns could result)g this valv "l
l Ea'dela/IOkNe" N
return to power.
System modifications would be'necessary to enable the Q quarterly performance of this testing.
The cost of these modifications and
- 3' the possible costs due to delays in plant startup would be burdensome for the licensee.
The licensee's proposed alternative, to full stroke exercise th'is valve during SLC injection testing each refueling outage, would provide reasonable assurance of operational readiness.
+
Based on the determination that compliance with the Code required testing is impractical, that the licensee's proposed testing would providt a reasonable alternative to the Code requirements, and considering the burden on,
the licensee if the Code requirements were imposed, relief may be granted as l
requested.
3.8 Reactor we Isolation Coolina 3.8.1 Cateaory C Valves e
3.8.1.1 Relief Recuest.
The licensee has requested relief from the exercising frequency requirements of Section XI, Paragraph IWV-3520, for the' l
reactor core isolation cooling (RCIC) pump suction check '.aive from the -
l' #
suppression pool, 49-1(2)030.
The licensee has pecposed part-stroke I'"
I exercising this check valve quarterly and fdi-stroke exercising it during1 refueling outages.
- t 2
-e I
+
3.8.1.1.1 Licensee's Basis For Reauestino Relief--To achieve.the required flow for full exercising this check valve, the HPCI return line'to' the suppression pool, via HV 55 1(2)F071, shall be utilized in conjunction with the RCIC suppression pool return line.
in order to establish this flow path valve interlocks must be lif ted.
This is not practical during power 38 Ty
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TF-'#'Te-e'-1r' M1'9TV-"FT*T
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operationastheautomaticisolationcapabilitiesofHV-492(2)F022,whichis reg' s to close upon RCIC initiation ind low reactor water level, would be defe a.
In addition, HV 49-(2)F029 and F031, which are containment isolation valves, would not be able to perform their. automatic isolation function.
Testing during cold 1.hutdown could delay plant startup.
This check valve will be partially stroked during quarterly pump test and full exercised during refuelings.
3.8.1.1.2 Evaluation Due to system design, reactor core isolation cooling system flow cannot be utilized to full stroke exercise this valve during power operation or cold shutdown.
The RCIC system suction must be aligned to the suppression pool to 'ull stroke exercise this valve and this would result in the introduction of low quality water into the condensate storage tank and the reactor vessel.
This could force a unit shutdown due to the inability to maintain reactor coolant chemistry specifications.
Additionally, this testing would require defeating system interlocks and inhibiting automatic safety functions.
The flow path used to part stroke exercise this valve quarterly is from the suppression pool through the pump minimum flow line returning to the i
, suppression pool.
The relatively small volume of degraded water can be flushed from the system and processed.
However, following a full stroke exercise test with flow, considerable effort would be required to reestablish water quality in the condensate storage system.
Full stroke exercising these valves with flow would require a signincant es enditure of time and manpower and performing this testing during cold thutdowns could, therefore, result in a delay in the return to power.
System modifications would be necessary to enable the performance of this testing at the Code required frequency.
The cost of these modifications and the possible costs due to delays in plant startup would be burdensome for the licensee.
The licensee's proposed alternative, to part stroke exercise this valve quarterly during pump testing and full stroke exercise it during refueling outages, would provide reasonable assurance of onerational readiness.
39
I Based on the determination that compliance Cith the Code required J'
testing is impractical, that the licensee's proposed alternate testing would
'i provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested, j
3.9 Residual Heat Removal 3.9.1 Cateoory B Valves 3.9.1.1 Relief Reouest.
The licensee has requested relief from the exercising frequency and stroke timing requirements of Section XI, Paragraphs !WV 3412 and.3413 respectively, for the residual heat removal service water (RHRSW) system emergency core flood isolation valve, HV 51 1(2)F073.
The licensee has proposed exercising and stroke timing this valve during refueling outages.
3.9.1.1.1 Licensee's Basis For Raouestino Relief--Valves HV 51 1F073, HV 51 lF075 and HV 51 1F078 provide isolation between the radioactive RHR system and non radioactive RHRSW system.
Periodic exercising of the IF078 and IF075 contaminates the volume between the IF075 and IF073 with C060, ZN65 and other long lived isotopes.
Numerous attempts to flush the volume have been unsuccessful resulting in a substantial volume of contaminated water to rad waste and contamination releases to the spray pond through the RHRSW system when IF073 is opened.
To remain consistent with 1.E. Bulletin No. 80 10 and minimize environmental and radwaste impact, l
testing of HV 51-lF073 will be performed at refueling A modification for an improved flush connection is being pursued; however, it is anticipated this potential for cross contamination will still exist.
Based on the above discussion for Unit I this same condition is anticipated to exist on Unit 2.
Therefore, the required testing for HV 51 2F073 will be performed at refueling.
No part stroke will be performed.
This check valve will be exercised and stroke timed at refueling.
40
1 3.9.1.1.2 Evaluation Exercising valve HV 51 1(2)F073 results in
' radioactive contamination of the RHR5W system.
The cross contamination is minimized by flushing the upstream piping, however, this creates large volumes of radioactive waste.
The costs of handling and disposing of this radioactive waste would be burdensome for the licensee due to the costs involved.
The licensee's proposed alternative, to exercise and stroke time this valve during refueling outages would provide rehsonable assurance of operational readiness.
Based on the determination that compliance with the Code requirements is impractical, that the licensee's proposed alternate testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.10 Core Sorav 3.10.1 Cateaory A/C Valves 3.10.1.1 Relief Recuest.
The licensee has requested relief from the exercising frequency requirements of Section XI. Piragraph IWV 3520, for the core spray injection check valve. HV 52 1(2)08.
The licensee has proposed full stroke exercising this check valve open during refueling outages using a
[
chainfall and closed using Appendix J Type C, and Section XI leak rate j
testing.
3.10.1.1.1 Licensee's Basis For Reauestino Relief The above valve is equipped with air actuators; however, these actuators a're not designed to open the valves.
The actuator is designed to provide spring assistance for i
valve closure only.
Flow exercising in the forward direction can only be l
accomplished by injection into the vessel which is not performed.
Therefore, as an alternate means of forward exercising, the valve will be manually full opened by the use of a chainfall.
Forward exercising, if attempted during cold shutdown, could result in a delayed plant startup.
Exercising in the reverse direction will be accomplished during Appendix J and Section XI leak rate testing.
No part stroke exercising will be performed.
This check valve 41
will be full stroke exercised in the forward direction at refueling by the use
- l' of a chainfall.
Reverse flow closure will be verified at refueling by Appendix J and Section XI leak rate testing.
3.10.1.1.2 Evaluation -This valve is a containment isolation check valve located outside the containment.
IWV3522(b)containsthetest method requirements for exercising check valves using a mechanical exerciser.
The licensee's proposed test method, to exercise this check valve to the open position using t chainfall, would be acceptable provided the licensee adheres to these requirements. However, the licensee has not provided a justification that demonstrates exercisirg this check valve to the open position quarterly or during cold shutdowns would be impractical or would result in hardship without a compensating increase in the level of quality and safety.
The only method available to verify the closure capability of this valve is by leak testing.
This valve is located outside the containment, however, some of the valve test connections are located inside containment and are inaccessible during power operation.
Leak testing during cold shutdowns is impractical since the containment is often maintaine/ inerted.
This testing would require a significant amount of time for G il equipment setup, test perfcrmance, and test equipment removal and could result in a celay 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.
Verifying the reverse flow closure of this valve using Appendix J. Type C, leak rate testing during refueling outages would provide reasonable assurance of valve operational readiness in the closed position.
Based on the determination that verifying the closure capability of this valve quarterly or during cold shutdowns is impractical, that the licensee's proposed alternate testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if this Code requirement was imposed, relief may be granted to verify the closure capability of this check valve during refueling outages.
However, relief from-the Code exercising frequency requirement for the open position should not be
-granted.
42
3.11 Hiah Pressure Coolant Iniection 3.11.1 Cateaory C Valves 3.11.1.1 Relief Reauest.
The licensee has requested relief from the exercising frequency and method requirements of Section XI, Paragraph IWV 3520, for the high pressure coolant injection (HPCI) pump suction from thesuppressionpoolcheckvalve,551(2)F045.
The licensee has proposed part stroke exercising this valve quarterly and demonstrating its full stroke open capability by disassembly during refueling outages.
3.11.1.1.1 Licensee's Basis For Reauestina Relief -Full stroke exercising of these valves in the forward direction by normal system flow paths would require injecting poor quality suppression pool water into either the reactor vessel or the condensate storage thnk.
Technical Specification 3.4.4 requires reactor coolant system conductivity and chloride levels to be within specified levels.
Injection of poor quality water from the suppression pool into the condensate storage tank (reactor coolant makeup water) or reactor coolant system, would result in increased chloride and conductivity levels exceeding Technical Specification limits.
These valves are exercised by returning flow to the suppression pool via the test return loop; however, due to the smaller line size of the test retura loop, the flow rates that would be obtained would result in only a partial opening of the valves.
Because no means is available to verify a full stroke in the open direction for these valves, valve disassembly will be required.
Disassembly of the valves, if attempted at cold shutdown, could result in a delayed plant startup.
l l
l These check valves will be part stroked in the forward direction quarterly and full stroke exercise will be verified at refueling by valve disassembly.
3.11.1.1.2 Evaluation Due to system design, HPCI system flow l
cannot be utilized to full stroke exercise this valve during power operation or cold shutdown.
The HPCI system suction must be aligned to the suppression i
pool to full-stroke exercise this valve and this would result in the 43
...1,
I introduction of relatively low quality tater into the condensate storage tank I
j and the reactor vessel.
This could force unit shutdown due to the inability l
to maintain reactor coolant chemistry specifications.
I 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.
l l
The licensee has proposed verifying the full stroke open capability of these check valves by disassembly and inspection.
The NRC staff positions regarding check valve disasse***
and inspection are explained in detail in l
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 l
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 after reassembly, would provide reasonable assurance of operational readiness.
However, the NRC staff considers vilve O sassembly and insper. tion to be a maintenance procedure with inherent risks which make its use as a routine 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 l
l techniques during a reduced flow test at least once each refueling outage.
Based on the determiration that compliance with the Code requirements is impractical, and considering the burden on the licensee if Code requirements were imposed, relief may be granted provided the licensee perfoms a partial flow test of the disassembled valve before it is returned to evice. The licensee should actively pursue the use of nun intrusive diagnostic 44
techniques to demonstrate that this valve stings fully open during partial flow testing.
If another method is developed to verify the full stroke capability of this check valve, this relief request should be revised or withdrawn.
3.11.1.2 Relief Reouest.
The licensee has requested relief from the exercising fregiancy and method requirements of Section XI, Paragraph IWV 3520, for the HPCI pump discharge check valves to feedwater and core spray systems, 55 1(2)058 and 1(2)059.
The licensee has proposed demonstrating the full stroke capability of these check valves by disassembly during refueling outages.
3.11.1.2.1 Licensee's Basis For Reauestino Relief Verifying forward flow operability during operation would require the injection of relatively cold water from the condensate storage tank into the reactor vessel via the HPCI pump.
The introduction of relatively colder water into the Reactor Coolant System would result in an excessive number of thermal cycles to system piping and components.
Additionally, the introduction of colder water would increase reactivity due to the colder moderator temperature.
Full exercise, therefore, can be accomplished only by valve disassembly.
Valve disassembly, if attempted at cold shutdown, could result in a delayed plant startup.
l l
These check valves will be full stroke exercised in the fonvard direction at refueling by valve disassembly.
3.11.1.2.2 Evaluation The only flow path available' to full-stroke exercise these check valves with flow is into the reactor vessel, it is impractical to perform this testing quarterly during power operation because the injection of relatively cold boron solution would result in thermal cycles to SLC and RCS components, and reactivity transients that could cause a reactor shutdown.
Because steam is required to operate the HPCI pump, a full stroke exercise test with flow could only be performed den the reactor coolant system is hot.
l 45 l
The Code required testing could only be performed after significant l,
system modifications which would be burdensome for the license due to the cost involved.
The licensee has proposed verifying the full stroke open capability of these check val"es by sample disassembly and inspection.
The NRC staff I
positions reg uding 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 should investigate methods of part stroke exercising these check valves.
)
An interim period is necessary to give the licensee time to complete their investigation, changes to the test procedures, and any system design f
changes necessary to perform post inspection valve exercising.
imediate compliance could result in an extended outage which would be a burden for the licensee due to the costs involved.
The licensee's proposed alternative, while not acceptable for the long term, should provide reasonable assurance of operational readiness in the interim since the incidence of improper reassembly should be low.
Therefore, based on the determination that l
compliance with the Code requirements is impractical, and considering the burden on the licensee if the Code requirements were imposed, interim relief i
may be granted for one year or until the next refueling outage, whichever is l
greater.
In the interim, the licensee may use disassemb',y and inspection to verify the full stroke operability of these check valves without a post inspection exercise test with flow.
l The NRC staff considers valve distssembly and inspection to be a I
maintenance procedure with inherent risks which make its use as a routine substitute for testing undesirable when other testing methods are possible.
l It may be possible to verify that these valves move to their fully open i
46 i
I position by use of non intrusive diagnostic testing techniques during a f
reduced flow test at least once each refueling outage.
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 l
method is devel d to verify the full-stroke capability of these check f
valves, this relief request should be revised or withdrawn.
I 3.12 Primary Containment Instrument Gas 3.12.1 Cateoorv A/C Valves 3.12.1.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI. Paragraph IWV 3520, for the following automatic depressurization system (ADS) accumulator nitrogen supply check valves.
The licensee has proposed full stroke exercising these check valves during refueling outages and cold shutdowns when the containment is de inerted.
59 1(2)001 591(2)005A 59 1(2)0058 591(2)056 591(2)l12 591(2)128 3.12.1.1.1 Licensee's Basis For Reouestino Relief These valves are all located inside the primary containment.
Testing of these valves requires the use of test connections which are alsc located inside the primary containment.
During power operation and cold shutdown, the containment atmosphere is normally inerted with nitrogen limiting access to emergencies only.
In addition, high radiation levels during power operations prohibit containment entry.
Forward (when applicable) and reverse exercising will be verified during all refueling outages and during cold shutdowns when the primary containment is de inerted.
3.12.1.1.2 Ey.11ptj a The containment is maintained inerted during power operation and during most cold shutdowns.
Exercising these
<alves would require a containment entry.
It is impractical to exercise thea valves quarterly during power operation because this would require the l
47
\\
I,'
reactor to be shutdown and the containment de inerted.
Exercising these (l
valves every cold shutdown would also require de inerting of the containment.
Shutting down the reactor and/or de inerting the containment to enable testing at the Code required frequency would be burdensome for the licensee due to the costs involved.
i The licensee's proposal, to full-stroke exercise these valves during i
cold shutdowns when the containment is de inerted and during refueling
(
outages would provide reasonable assurance of operational readiness and would be a reasonable alternative to the Code requirements, j
Based on the determination that compliance with the Code exercising j
i frequency requirements is impractical, that the licensee's proposed alternate testing would provide a reasonable alternative to the Cooc requirements, and i
considtring the burden on the licensee if the Code requirements were imposed, f
relief may be granted as requested.
3.12.2 Cateoorv C Valves 7
l 3.12.2.1 Relief Reauest.
The licensee has requested relief from the exercising frequency requirements of Section XI Paragraph IW 3520, for the following ADS accumulator nitrogen supply check valves quarterly.
The licensee has proposed full stroke exercising these check valves during refueling outages and cold shutdowns when the containment is de inerted.
l 591(2)023H 59 1 59 1 023K 59 1 023M 591(2)023E (2)024E 59 1 024H 59 1 024K 59 1(2)023S 59 1(2)024M 59 1(2)024S 59 1 131E 59 1 131H 591(2)l31K 591(2)l31M 59 1 1315 3.12.2.1.1 Licensee's Basis For Reauestino Relief-These valves l
are all located inside the primary containment.
Testing of these valves l
requires the use of test connections which are also located inside the primary containment.
During power operation and cold shutdown, the containment atmosphere is normally inerted with nitrogen limiting access to j
emergencies only.
In addition, high radiation levels during power operations prohibit containment entry.
1
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t 48
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..w man
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l Forward (when applicable) and reverse exercising t;ill be verified durihg ll refueling 09tages and during cold shutiowns when the primary containsent a
is de inerted.
3.12.2,1.2 Evaluation The containment is maintained inerted during power operation and daring most cold shutdowns.
Exercising these valves would require a containment entry.
It is impractical to exercise these valves quarterly during power operation because this would require the reactor to be shutdown and the containment de inerted.
Exercising these valves every.old shutdown would also require 1e inerting of the containment.
Shutting dnwn the renctor and/or de inerting the containment to enable testing at the Code required frequency would be burdensome for the licensee due to the costs involved.
The licensee's proposal, to full stroke exercise these valves during cold shutdowns when the containment is de inerted and during refueling outages would provide reasonable assurance of operational readiness and would be a reasonable alternative to the Code requirements.
Based on the determination that compliance with the Code exercising frequency rec;uirements is impractical, that the licensee's proposed testing would provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.13 Control Structure Chilled Water 3.13.1 Q1gstary B Yalves 3.13.1.1 Relief Reauest.
The licensee has requested relief from the stroke tising require'
.s of Section XI, Paragraph IWV 3413, for the standby gas treatment access and room supply isolation valves, SV 90-045A, -0458, 047A, and 0478.
The licensee has proposed exercising and fail safe testing these valves quarterly without stroke time measurement.
49
3.13.1.1.1 Licensee's Basis For Reouestino Relief..These valves are solenoid valves which are not provided with local or remote position indication.
The only means to verify their position is by observing the i
performance of their associated cooler.
Measuring of the valve stroke time using this indirect measurement of valve position does nat provide consistent enough results to detect valve degradation.
4 The valves will be exercised and fail scle tested quarterly to ensure operability.
Stroke time will not be measured.
3.13.1.1.2 Evaluation These solenoid operated valves are not equipped with position indication and valve design it such that observation of valve stem position is not possible.
With the current system design, precise
{
measurement of stroke time is not possible and trending stroke times is not practical.
Significant modifications, such as valve replacement, would be necessary i
to ervole compliance with the Code stroke timing and trending requiremcnts, i
These modifications would be burdensome for th9 licensee due'to the costs i
involved.
However, the licensee's proposal provides no mians of detecting valve degradation.
The licensee should develop a method f.f monitoring the condition of these valves and detecting degtadation.
Despite the inability to obtain trendable stroke times without system modifications, it may be possible l
for the licensee to confirm a change in position by indirect means and verify l
that the stroke times are less than a reasonable maximum limit.
- i i
t Requiring immediate performance of this testing would be burdensome for j
the licensee, therefore, an interim period is necessary to give the licensee l
time to investigate and implement a method to monitor for valve degradation.
The licensee's proposed testing, while not adequate for the long term, does f
demonstrate valve operability and would provide reasonable assurance of l
operational readiness in the interim.
Therefore, interim relief may be e
i granted for one year or until the next refueling outage, whichever is greate,
?
to continue the current testing while the licensee investigates acceptable alternatives.
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1 APPENDIX A IST PROGRAM AN0iiALIES -0ENTIFIED DURING THE REVIEW 1
i f
I A-1
(
/
APPEN0!X A IST PROGRAM AN0MAllES FOUND OURING THE REU EW Inconsistencies and omissions in the licens2e's program noted during the course of this review are sumarized below.
The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in thfs report.
1.
In item P.2 of the working meeting minutes u.ted Harch 31, 1988, the licensee comitted to remove the references in their program to the forward flow testing performed on Residual Heat Removal systes check valves Sl-1(2)F031A, -1(2)F0318, -1(2)F031C, and -1(2)F0310. A review of the current program indicates this channe has nut bee. iade.
2.
In item P.3 of the working meeting minutes dat e March 31, 1988, the licensee comitted to investigate a positive method of full-stroke exercising Fasidual Heat Pemon: mini flow check valves 511(2)F046A, 1(2)F046B, 1(2)F046C, and -1(1)F0460.
This remains an open itse for the licensee.
3.
In item Q.3 of the working meeting minutes dated March 31, 1988, the licensee comitted to investigate a positive method of full stroke exercising Core Spray syp.ee pump mini-flow check valves 521(2)F036A, 1(2)F0368, 1(2)F036C, and 1(2)F0360.
This remains an open itse for the licensee.
4.
In pump relief request GPRR 2, the licensee requested relief from tiie Code instrumentation accuracy requirements for all pumps in the IST program with the exception of the safeguard piping fill, diesel fuel oil transfer, and standby liquid control pumps.
Relief may be granted 4r those instruments that proviu *.no same or better indicatior accuracy at the reference value as requit a by the Code.
The second category of instruments addressed by this rn'itef regtest do not provide the same indication accuracy at reference values as required by the Cede.
Additionally, the licensee did not identify euch affected pump instr:iment, the reference value, and the full scale t
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- range, therefore, it is not possi'le to determine the available
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O accuracies and the effect that use of these instruments would have on the licensee's ability to monitor pump hydraulic condition and detect degradation.
Since neither the actual Indication accuracy nor the effect that their use will have on the licensee's ability to detect pump hydraulic degradation is known, relief should not be granted for those installed instruments that do not provide the same or better indication accuracy at the reference value as required by the Code.
(Reference section 2.1.2 of this report.)
5.
In valve relief request GVRR 1, the licensee has requcsted relief from the Code leak rate testing requirements 6 all containment isolation valves. Where individual leakage limit.
an be assigned and valve leakage determined, the licensee should comply with the requirements of IWV-3426 and -3427(a).
For situations where there are multiple containment isolation valves branching from a common header, ascribing all leakage through the penetration to one valve could cause the performance of baseless maintenance on operable valves.
The licensee has stated that maximum leakage rates will be assigned to each valve group and if the measured leakage exceeds the assigned group limit, corrective actions will be taken as requirod by Paragraph IWV-3427.
This test method would provide an acceptable level of quality and safety if the assigned limiting leakage rate for each valve group is conservatively established regarding the number and sizes of valves in the group.
The f
assigned maximum group leakage rates should be based on the smallest valve in the group so that corrective actions are taken whenever the leak-tight integrity of any valve of that group is in question.
For valves that may only be tested in groups, relief may be granted provided the assigned mnimum group leakage rates are based on the smallest valve in the gre
'o that corrective actions are taken whenever the leak-tight integrity ot any valve of that group is in question.
(Reference section
{
3.1.1.1 of this report.)
6.
In valve relief request GVRR 4, the licensea has proposed verifyia.; the closure capability of each set of series check valves as a urit.
Relief may be granted provided both valves in the pair are declared
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inoperable, disassembled, and repaired or replaced if excessive leakage is detected during testing.
(Reference section 3.1.4.1 of tnis report.)
7.
in valve relief request GVRR 5, the licensee has proposed full stroke exercising each set of four series parallel vacuum relief check valves as c unit.
The proposed group testing gives no indication of the individual valve condition.
Since two failures must occur prior to detection by group-testing, repairing only one valve is not acceptable. When the group fails to pennit the required forward flow, all valves in the group are suspect and should be declared inoperable until they are repaired, replaced, or individually verified capable of performing their safety function.
Relief may be granted provided all valves are repaired or replaced as necessary if the opening capability of any of these valves is questionable.
In response to a request for additional information from the NRC staff, the licensee stated that valve closure is verified by a temperature sensor in the upstream line that provides an alarm in the control room if reverse flow occurs.
For this series-parallel arrangement, this test verifiss that at least one of the parallel valve combinations is closed, but it does not provide infont.< 'on about the condition of the remaining valve combination.
Ade ate isolation valves and test taps are available to leak test each pa; lel valve combination to verify that each individual valve is capable of preventing reverse flow.
Since the Code requirements for verifying the closure espability of each valve can be met, the licensee is expected to comply with this Code requirement.
(Reference section 3.1.5.1 of this report.)
8.
In valve relief request 20-VRR 1, the licensee proposed testing the diesel generator air start solenoid valves as a unit during monthly diesel testing and to alternately isolate the air headers during die 3al testing every 18 months.
Piping and Instrument Drawing ISI-M 20 shows manual valves that could possibly be used to isolate an air start train during diesel testing to verify operibility of ths other train.
Relief may be granted provided the licensee assigns a maximum limiting diesel start time which is less than or equal to the l
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Technical Specification limit and verifies the operability of the valves in
- I each air start train at least quarterly by isolating one air start train on an alternating basis during diesel testing.
9.
In valve relief request 55 VRR 1, the licensee has proposed verifying the full stroke open capability of the HPCI pump suction from the suppression pool check valve, 55-1(2)F045, 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 expecm to be performed after disassembly an.1 inspection is completed but before the valve is returned to service.
Relief may be granted to disassemble'and inspect this valve provided the licensee performs a partial flow test of the disassembled valve before it is returned to service.
1he 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 check valves, this relief request should be revised or withdrawn.
(Reference section 3.11.1.1 of this report.)
- 10. In valve relief request 55-VRR 2, the licensee has proposed verifying the full stroke open capability of the HPCI pump discharge check valves, 551(2)058 and -1(2)059, using disassembly and inspection.
The licensee should investigate methoos of part stroke exercising these check valves.
Interim relief may be (fp?td fe these valves for cae year or until the next refueling outage, d !chever is greater, to give the licensee time to complete their investig n %n, the test procedures, and any system design changes necessary to perform post-inspection part-stroke exercising.
In the interim, the licensee may use disassembly and inspection to verify A6 l
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the full stroke operability of these check valves without an ensuing part stroke exercise test with flow.
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 check valves, this relief request should be revised it withdrawn.
(Reference section 3.11.1.2 of this report.)
11.
Id valve relief request GVRR 6, the licensee has proposed verifying the closure capability of the below listed series sets of stay fill check valves using disassembly and inspection during system r.ini-outages w refueling outages.
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 practical.
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.- Relief may be granted provided the licensee part-stroke exercises the valves to the open po:iition with flow after they have been reassembled.
The licensee should actively investigate ways, other than disassembly and inspection, of verifying the closure capability of these valves.
If anothtr method is developed to verify the reverse flow closure capability of these check valves, this relief request should be revised or withdrawn.
(Refvence-section 3.1.4.2 of this report.)
12.
In valve relief request 41 VkR 2, the licensee has requested relief from the Code stroke timing requirements for ADS valves PSV 41-1(2)F013E, H K, M, and S.
To monitor for valve degradation, the licensee should assign a maximum stroke time limit to these valves that is based on previous test data and verify that they stroke within that limit during testing.
The measured stroke times need not be trended or compared to previous values, but if the maximum limit is exceeded, the i
valve should be declared inoperable and corrective action taken in l
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- 'e action taken in accordance with IWV-3417(b).. Relief may be granted provided the licensee adopts this provision regarding valve stroke time measurement.
(Reference section 3.3.2.1 of this report.)
- 13..
In valve relief request 52-VRR41, the licensee has proposed exercising the core spray injection-check valve, HV-52-1(2)08 to the open position during refueling outages using a chainfall.
IWV-3522(b) contains the test method requirements for exercising check valves using a mechanical exerciser.
The licensee's proposed test method would be acceptable provided the licensee adheres to these requirements. However, the licensee has not provided_a justification that. demonstrates exercising this che:k valve to the open position quarterly or during cold shutdowns would be impractical or would' result in hardship without a compensating increase in safety or quality.
Therefore, relief from the Code exercising frequency requirement for the epon position should not be granted.
(Reference section 3.10.1.1 of this report.)
14.
In valve relief request 90 VRR-1, the licensee has requested relief from the Code stroke timing requirements for the standby-gas treatment access and room supply isolation valves, SV-90 045A, -0458, -047A, and -0478.
The licensee has proposed exercising and id safe testing these valves quarterly without stroke time measurement.
However,-the licensee's l
proposal provides no means of detecting valve degradation. The licensee l
should develop a method of monitoring.the condition of these valves and detecting degradation.
Despite the inability-to obtain trendable stroke times without system modifications, it may be possible for the licensee j
to confirm a change in position by indirect means and verify that the stroke times are less than a reasonable maximum limit.
Interim relief may be granted for one year r until the next refueling-outage,-
whichever it greater, te continue the current testing while the licensee investigates acceptc51e alternatives.- (Reference section 3.13.1.1 of this report.)
15.
In a proposed Technical Specification change dated November 17, 1989, the Philadelphia Electric Company indicated that the scram accumulator check valves are tested for closure by performing a pressure decay test A-8
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for a period of 30 seconds. However, the submittal did not indicate the e
allowable pressure decay over this time interval. Also, the licensee's IST program lists these valves as Category C.
These valves perform the safety function of maintaining hydraulic control unit accumulator pressure above the low pressure set point when the reactor is below 600 l
psig and both control rod drive pumps are not in operation. These valves should be categorized A/C.
Since the function of these valves is to maintain accumulator pressure, performing a pressure decay test in lieu of a letk rate test is acceptable provided the duration and permissible pressure decay demonstrates that these valves are capable of performing their safety function.
The licensee should revise the categori::ation of these valves and provide the NRC with information describing the pressure decay acceptance criteria used in this test.
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Mr. George J. Beck Limerick Generating Station i
4 Philadelphia Electric Company Units 1 & 2 CC:
J. W. Durham, Sr., Esquire Mr. Thomas Gerusky, Director Sr. V.P. & General Counsel Pyreau of Radiation Protection Philadelphia Electric Company h
ept. of Environmental Resources 2301 Market Street P. O. Box 2063 Philadelphia, Pennsylvan4 19101 Harrisburg, Pennsylvania 17120 Mr. Rod Krich 52A-5 Single Point of Contact Philadelphia Electric Company P. O. Box 11800 955 Chesterbrook Boulevard Harrisburg, Pennsylvania 17108-188 Wayne, Pennsylvania 19087-5691 Mr. Graha- " Leitch, "ica Pr-sident Mr. Garrett Edwards Limerick C 'o ating Stu Superintendent-Technical Post OffL dan A Limerick Generating Station Sar.atoga, P nrdylvania 19464 P. O. Box A Sanatoga, Pennsylvania 19464 Mr. John Doering Plant Manager Mr. Gil J. Madsen Limerick Gliw ating Station Reugiatory Engineer P.O. Box A Limerick Generating Station Sanatoga, Pennsylvania 19464 P. O. Box A Regional Administrator Sanatoga, Pennsylvania 19464 U.S. Nuclear Regulatory Comission Library Region 1 US Nuclear Regulatory Comission 475 Allendale Road Region I King of Prussia, PA 19406 475 Allendale Road i
King of Prussia, PA 19406 Senior Resident inspector US Nuclear Regulatory Comission P. O. Box $96 Pottstown, Pennsylvania 19464 v
Mr. George A. Hunger Project Manager Limerick Generating Station P. O. Box A Sanatoga, Pennsylvania 19464 Mr. Larry Hopkins Superintendent-Operations Limerick Generating Station y
P. O. Box A Sanatoga, Pennsylvania 19464 a.
Or
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