ML20213G269
| ML20213G269 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 11/03/1986 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20213G263 | List: |
| References | |
| TAC-60876, NUDOCS 8611170412 | |
| Download: ML20213G269 (21) | |
Text
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- o UNITED STATES g
8 o NUCLEAR REGULATORY COMMISSION
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i SUPPLEMENTAL SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION i
RELATED TO REQUESTS FOR RELIEF FROM INSERVICE TESTING REQUIREMENTS i FOR THE EMERGENCY DIESEL GENERATOR AUXILIARY SYSTEMS NORTHEAST NUCLEAR ENERGY COMPANY, ET AL.
l MILLSTONE NUCLEAR POWER STATION, UNIT NO. 2 i
DOCKET NO. 50-336 Introduction 4
Technical Specification 4.0.5 for the Millstone Nuclear Power Station, Unit l No. 2 (Millstone 2) states that inservice testing (IST) of ASME Code Class 1,
! 2, and 3 pumps and valves shall be performed in accordance with Section XI of
, the ASME Boiler and Pressure Vessel Code (the Code) and applicable Addenda, as required by 10 CFR 50.55a(g). 10 CFR 50.55a(g)(6)(i) authorizes the Commission
. to grant relief from Code requirements and to impose such alternative
{ requirements as it determines is authorized by law upon making the necessary findings.
l By letter dated June 25, 1979, Northeast Nuclear Energy Company, et al. (NNEco or the licensee), submitted its pump and valve inservice testing program. The i program was revised by letter dated May 1, 1981. The staff issued, on May 4,
! 1983, a safety evaluation of its review of the licensee's proposed inservice testing program. The staff's safety evaluation delineated cases in which requested relief can be granted as requested, cases where relief cannot be j granted and others where testing or alternate testing would be necessary. The j staff found that the licensee had included all appropriate safety-related pumps and valves in the IST program except those in the fire protection system, emergency diesel generator auxiliary system and certain containment isolation i valves. The staff recognized the potential for certain code test requirements I to be impractical for some components and the existence of adequate alternate surveillance testing. However, the staff stated its position that all safety related pumps and valves be included in the IST program.
By letters dated March 12 and May 4, 1984, the licensee provided responses to 1 the staff's safety evaluation of May 4, 1983. The staff issued, on October 31, 1985, a supplemental safety evaluation addressing the licensee's responses to the staff's safety evaluation. This safety evaluation rescinded the request to include the fire protection system, however, restated the requirement that l
the safety related Emergency Diesel Generator auxiliary rystems be included in the inservice testing program and be tested to the requirements of ASME
- Section XI, Subsection IWP and IWV to the extent practical.
l I
l 8611170412 861103
, GR ADOCK 03000336 l T PDR
The licensee responded to the staff's supplemental safety evaluation by letter dated February 28, 1986 and subsequently to requests for additional information by letters dated August 29 and September 17, 1986. This safety evaluation is for these latter two letters which provided the staff with the licensee's proposed inservice testing program for the emergency diesel generator (EDG) auxiliary systems.
Evaluation and Discussion The licensee's surveillance program and requests for relief have been reviewed by the staff and are presented herein. Appendix A discusses Code Requirements and Appendix B lists drawings used during the course of this review.
The staff recognizes the limitations of the design, geometry and materials of constructicn of components such that certain code test requirements are impractical or imposition of those requirements would result in hardships or unusual difficulties without compensating increase in the level of quality or safety. The staff's review took into consideration the existence of adequate alternate surveillance testing during its evaluation of the operational readiness of each component. The licensee also conducts a weekly operability testing program of the emergency diesel generators. This testing is to start each EDG and run it under a 2100 kW load for 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br />. This testing also alternates (every 2 weeks) the redundant air start tanks for each EDG to check air start redundancy. The refueling outage EDG testing runs the EDGs under full load.
The staff's review determined that the licensee had incorporated the appropriate pumps and valves into the IST program. The licensee's relief requests are evaluated below. .
A. Pump Testing Program The licensee's IST program for the EDG auxiliary systems was examined to verify that all pumps whose function is safety related are included in the
, program and where practical are subjected to the periodic tests required t by the Code,Section XI. The staff's review found that these pumps are l being tested to the extent practical in accordance with Section XI except l-j for those pumps identified below for which specific relief from testing has been requested. The licensee's basis for each relief from the pump testing requirements and the staff's evaluation and conclusion for that request is summarized below.
- 1. System: EDG Fuel Oil Engine Driven Fuel Oil Pumps
- a. Relief Requested Relief is requested from the following requirements:
(1) The requirement to vary the resistance of the system until flow or differential pressure reference values are achieved.
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(2) The requirement to measure and record' flow and differential pressure readings.
(3) The requirement to measure inlet pressure.
(4) The requirement to verify proper lubricant pressure for this pump.
(5) The requirement to measure and record bearing temperature.
(6) The requirement to compare deviations from reference values with the limits given in Table'IWP-3100-2 and take specified corrective action.
- b. Code Requirement
Reference:
Appendix A, Pumps
- c. Licensee's Basis for Requesting Relief Basis for Relief (The paragraph numbers match those above):
(1) During diesel generator operation, system resistance cannot be varied. There is no provision for throttling or fuel control beyond that inherently provided by operation of the loaded diesel generator. Attempts to vary system resistance would degrade the performance of the die'sel generator.
The proposed alternate testing:
In lieu of varying system flow and resistance, the diesel generator will be operated at a fixed, procedurally specified load. All readings will be taken after the generator has been essentially stable at this load for at least 15 minutes.
(2) There are no instruments to measure fuel flow or fuel pump differential pressure. The supply to the pump is an elevated storage tank. Only fuel pump discharge pressure is available at the engine. Discharge pressure of this positive displacement pump is affected by the cleanliness of the downstream fuel oil filter.
The proposed alternate testing: ,
Measure pump discharge pressure when the engine is operating, as described in (1) above.
(3) As noted above, there is no inlet pressure monitoring ability. The diesel fuel oil supply tank normally operates within a 6-inch level range. Thus, static suction pressure is essentially constant.
t Inadequate inlet pressure would be identified by low pump discharge pressure or inability of the diesel generator to achieve Technical Specification load carrying requirements.
The proposed alternate testing:
The fuel oil supply tank will be maintained to the normal level range during testing.
(4) This pump is engine-driven and lubrication requirements are met by the engine lubrication system. No instrumentation is provided to allow individual unit monitoring. Proper operation of the engine lube oil system assures proper lubrication of the unit.
The proposed alternate testing:
Proper operation of the engine lubrication system will be verified during the test.
(5) Bearings for this pump are inaccessible for measurement.
In addition, experience has shown that to be effective in identifying bearing distress, t earing temperature monitoring must be continuous rather than periodic. Failing bearings often exhibit fluctuations between normal and abnormal temperatures. Further, one potential alternative, moni-toring of the housing temperatt.re, does not provide mean-ingful monitoring of bearing tr.mperature since the housing temperature is significantly less responsive to bearing metal temperature changes.
No alternate testing is proposed.
(6) Reference values for the auxiliary systems of a loaded diesel generator are more susceptible to influences of
, ambient conditions and cooling water temperatures than normally experienced in safety-related pump testing. The pump discharge pressure is low (<30 psig), thus the acceptable range (per Table IWP-3100-2) is less than 4 psig. Normal system variations can exceed this range without impacting diesel generator operability.
The proposed alternate testing:
Pump discharge pressure will initially be compared to the limits for differential pressure specified in Table IWP-3100-2. If experience shows that these ranges cannot be met, range limits which allow the pump to fulfill its function will be specified as allowed by Article IWP-3210.
- d. Evaluation The staff agrees with the licensee's basis and, therefore, relief should be granted from requirements of Section XI for the pump parameters as listed in the relief request. The licensee has demonstrated that with the system design, configuration and installation, it is impractical to obtain the measurements in the Code specified manner,for these parameters,
- e. Conclusion The staff concludes that due to the pump and system design, the relief requested should be granted. The alternate testing is imposed and should give reasonable assurance of pump operability required by the Code; therefore, the s aff concludes that the relief granted will not endanger life or property or the common defense and security of the public.
Clean Oil Pumps
- a. Relief Requested i
Relief is requested from measuring and recording inlet pressure, differential pressure, flow, lubrication, vibration, and bearing temperature.
- b. Code Requirements
Reference:
Appendix A, Pumps a *
- c. Licensee's Basis for Requesting Relief There is no installed instrumentation which can be used to measure inlet pressure, differential pressure or flow. There are no accessible bearings. The unit is mounted on the diesel engine structure precluding meaningful vibration measurements.
There is no separate lubrication supply to the units.
This portion of the fuel oil system consists of two cross connected 9.5 gallon tanks, each equipped with a clean oil return pump. This system operates intermittently to return fuel leakage to the fuel supply tank. Only one pump is required for operation. The redundant pump provides reasonable assurance that diesel generator operability will be maintained. The proposed alternate testing will provide adequate assurance that t
this small positive displacement pump is capable of supporting diesel engine operability.
The proposed alternate testing: i
Each pump will be operated independently during diesel engine testing and observed to verify that the pump starts, reduces level in the clean oil tank and shuts off in response to changing tank levels. Testing frequency will be such that each pump will be tested once per calendar quarter.
- d. Evaluation The staff agrees with the licensee's basis and, therefore, relief should be granted from requirements of Section XI for the pump parameters as listed in the relief request. The licensee has demonstrated that with the system design, configuration and installation, it is impractical to obtain the measurements in the Code specified manner for these parameters.
- e. Conclusion The staff concludes that due to the pump and system design, the relief requested should be granted. The alternate testing is imposed and should give reasonable assurance of pump operability
, required by the Code; therefore, the staff concludes that the relief granted will not endanger life or property or the common i defense and security of the public.
- a. Relief Requested Relief is requested from the following requirements:
(1) The requirement to vary the resistance of the system until flow or differential pressure refarence values are achieved.
(2) The requirement to measure and record flow and differential pressure readings.
(3) The requirement to measure inlet pressure.
(4) The requirement to verify proper lubricant pressure for this pump.
(5) The requirement to measure and record bearing temperature.
! (6) The requirement to compare deviations from reference values with the limits given in Table IWP-3100-2 and take specified corrective action.
,_,-.-_..m _--_.,._____,_.m --_, _.,_ - - _..- _. - -
L. Code Requirement Reference Appendix A, Pumps
- c. Licensee's Basis for Requesting Relief Basis for Relief (The paragraph numbers match those above).
(1) During diesel generator operation, system resistance cannot be varied. There is no provision for lube oil flow control beyond that inherently provided by operation of the loaded diesel generator. Attempts to vary system resistance could cause failure of the diesel generator. )
The proposed alternate testing:
In lieu of varying system flow and resistance, the diesel generator will be operated at a fixed, procedurally specified load. All readings will be taken after the generator has been essentially stable at this load for at least 15 minutes.
(2) There are no instruments to measure lube oil flow or pump differential pressure. The supply to the pump is the engine sump. Sump level is closely controlled to manufacturer's requirements. Sump level is monitored as part of routine diesel generator operation. The principal,
- vital measurement is lube oil pressure within the engine.
The proposed alternate test'ing:
Measure engine oil pressure when the engine is operating as described in (1) above.
(3) As noted above, there is no inlet pressure monitoring ability. Sump level is closely controlled. Routine monitoring of sump level or low pump discharge pressure would identify reduced inlet head.
The proposed alternate testing:
The lube oil sump will be maintained in the normal level range during testing.
(4) This pump is engine-driven and lubrication requirements are met by the engine lubrication system. No instrumentation is provided to allow individual unit monitoring. Proper operation of the engine lube oil system assures proper lubrication of the unit.
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1 The propose,d alternate testing:
Proper operation of the engine lubrication system will be verified during the test.
- (5) Bearings for this pump are inaccessible for measurement.
In addition, experience has shown that to be effective in identifying bearing distress, bearing temperature monitoring must be continuous rather than periodic. Failing bearings often exhibit fluctuations between normal and abnormal temperatures. Further, one potential alternative, monitoring of the housing temperature, does not provide
, meaningful monitoring of bearing temperature since the housing temperature is significantly less responsive to bearing metal temperature changes.
No alternate testing be proposed.
- (6) Reference values for the auxiliary systems of a loaded
{ diesel generator are more susceptible to influences of
- ambient conditions and cooling water temperatures than 4
normally experienced.in safety-related pump testing. The pump discharge pressure is low (< 30 psig), thus the acceptable range (per Table IWP-3100-2) is less than
- 4 psig. Normal system variations can exceed this range without impacting diesel generator operability.
The proposed alternate testing:
Pump discharge pressure will initially be compared to the limits'for differential pressure specified in Table IWP-3100-2. If experience shows that these ranges cannot be met, range limits which allow the pump to fulfill its
- function will be specified as allowed by Article IWP-3210.
- d. Evaluation
. The staff agrees with the licensee's basis and, therefore, l relief should be granted from requirements of Section XI for the i pump parameters as listed in the relief request. The licensee l has demonstrated that with the system design, configuration and l' installation, it is impractical to obtain the measurements in the Code specified manner for these parameters.
1
e. Conclusion
The staff concludes that due to the pump and system design, the
, relief requested should be granted. However, the staff imposes i upon the licensee the requirement to define procedurally in the i
IST procedures the parameters and their allowable ranges (limits)
that specify the proper operation of the engine lubrication system. The alternate testing is imposed and should give reason-able assurance of pump operability as required by the Coce; there-fore, the staff concludes that the relief granted will not en-danger life or property or the common defer.se and security of the public.
- 3. System: EDG Jacket Water Cooling Engine Driven Jacket Water Cooling Pumps
- a. Relief Requested Relief is requested from the following requirements:
(1) The requirement to vary the resistance of the system until flow or differential pressure reference values are achieved. .
(2) The requirement to measure and reccrd flow and differential pressure readings.
(3) The requirement to measure inlet pressure.
(4) The requirement to verify proper lubricant pressure for this pump.
(5) The requirement to measure and record bearing temperature.
(6) The requirement to compare deviations from reference values with the limits given in Table IWP-3100-2 and take specified corrective action.
- b. Code Requirement
Reference:
Appendix A, Pumps
- c. Licensee's Basis for Requesting Relief i
Basis for Relief (The paragraph numbers match those above):
(1) During diesel generator operation, system resistance cannot
, be varied. There is no provision for throttling or cooling water flow control beyond that inherently provided by operation of the loaded diesel generator. Attempts to vary
( system resistance could cause failure of the diesel i
generator.
! The proposed alternate testing:
In lieu of varying system flow and resistance, the diesel generator will be operated at a fixed, procedurally
specified load. All readings will be taken after the generator has been essentially stable at this load for at least 15 minutes.
(2) There are no instruments to measure cooling water flow or pump differential pressure. The supply to the pump is an elevated atmospheric pressure expansion tank. Only pump discharge pressure is available at the engine.
The proposed alternate testing:
Measure p~ ump discharge pressure when the engine is operating as described in (1) above.
(3) As noted above, there is no inlet pressure monitoring ability. Expansion tank level is controlled. Routine monitoring of expansion tank level, increase in engine temperatures, or low pump discharge pressure would identify reduced inlet head.
The proposed alternate testing:
The expansion tank level will be maintained in the normal level range during testing.
(4) This pump is engine-driven and lubrication requirements are met by the engine lubrication
- system. No instrumentation is provided to allow individual unit monitoring. Proper operation of the engine lube oil system assures proper lubrication of the unit.
The proposed alternate testing:
Proper operation of the engine lubrication system will be verified during the test.
(5) Bearings for this pump are inaccessible for measurement.
In addition, experience has shown that to be effective in identifying bearing distress, bearing temperature monitoring must be continuous rather than periodic.
Failing bearings often exhibit fluctuations between normal and abnormal temperatures. Further, one potential alternative, monitoring of the housing temperature, does not provide meaningful monitoring of bearing temperature since the housing temperature is significantly less responsive to bearing metal temperature changes.
No alternate testing is proposed.
(6) Reference values for the auxiliary systems of a loaded diesel generator are more susceptible to influences of ambient conditions and cooling water temperatures than normally experienced in safety-related pump testing. The pump discharge pressure is low (< 34 psig), thus the acceptable range (per Table IWP-3100-2) is less than 4 psig. Normal system variances can exceed this range without impacting diesel generator operability.
The proposed alternate testing:
Pump discharge pressure will initially be compared to the limits for differential pressure specified in Table IWP-3100-2. If experience shows these ranges cannot be met, range limits which allow the pump to fulfill its function will be specified as allowed by Article IWP-3210.
- d. Evaluation .
The staff agrees with the licensee's basis and, therefore, relief should be granted from requirements of Section XI for the pump parameters as listed in the relief request. The licensee has demonstrated that with the system design, configuration and installation, it is impractical to obtain the measurements in the Code specified manner for these parameters.
- e. Conclusion The staff concludes that due to the pump and system design, the relief requested should be granted. The alternate testing is imposed and should give reasonable assurance of pump operability as required by the Code; therefore, the staff concludes that the relief granted will not endanger life or property or the common defense and security of the public.
- 4. System: EDG Air Coolina
~
Engine-Driven Air Cooling Pumps I a. Relief Requested Relief is requested from the following requirements:
(1) The requirement to vary the resistance of the system until flow or differential pressure reference values are achieved.
(2) The requirement to measure and record flow and differential pressure readings.
(3) The requirement to measure inlet pressure.
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(4) The requirement to verify proper lubricant pressure for this pump.
(5) The requirement to measure and record bearing temperature.
(6) The requirement to compare deviations from reference values with the limits given in Table IWP-3100-2 and take specified corrective action. -
- b. Code Requirement
Reference:
Appendix A, Pumps
- c. Licensee's Basis for Requesting Relief Basis for Relief (The paragraph numbers match those above):
(1) During diesel generator operation, system resistance cannot be. varied. There is no provision for throttling or cooling water flow control beyond that inherently provided by operation of the loaded diesel generator. Attempts to vary system resistance could degrade performance of the diesel generator.
The proposed alternate testing.
! In lieu of varying system flow and resistance, the diesel generator will be operated at a fixed, procedurally specified load. All readings will be taken after the generator has been essentially stable at this load.for at least 15 minutes.
(2) There are no instruments to measure cooling water flow or pump differential pressure. The supply to the pump is an elevated, atmospheric pressure expansion tank. Only pump discharge pressure is available at the engine.
The proposed alternate testing:
Measure pump discharge pressure when the engine is operating as described in (1) above.
(3) As noted above, there is no inlet pressure monitoring ability. Expansion tank level is controlled. Routine monitoring of expansion tank level, increase in engine temperatures, or low pump discharge pressure would identify reduced inlet head.
The proposed alternate testing:
The expansion tank level will be maintained in the normal level range during testing.
(4) This pump is engine-driven and lubrication requirements are met by the engine lubrication system. No instrumentation is provided to allow individual unit monitoring. Proper operation of the engine lube oil system assures proper lubrication of the unit.
The proposed alternate testing:
3 roper operation of the engine lubrication system will be verified during the test.
(5) Bearings for this pump are inaccessible for measurement.
In addition, experience has shown that to be effective in identifying bearing distress, bearing temperature monitoring must be continuous, rather than periodic.
Failing bearings often exhibit fluctuations between normal and abnormal temperatures. Further, one potential alternative, monitoring of the housing temperature does not provide meaningful monitoring of bearing temperature since the housing temperature is significantly less responsive to bearing metal temperature changes.
No alternate testing is proposed.
(6) Reference values for the auxiliary systems of a loaded diesel generator are more susceptible to influences of ambient conditions and cooling water temperatures than normally experienced in safety-related pump testing. The pump discharge pressure is low (< 11 psig), thus the acceptable range (per Table IWP-3100-2) is less than 1.5 psig. Normal system variations can exceed this range without impacting diesel generator operability.
The proposed alternate testing:
Pump discharge pressure will initially be compared to the limits for differential pressure specified in Table
. . IWP-3100-2. If experience shows these ranges cannot be met, range limits which allow the pump to fulfill its function will be specified as allowed by Article IWP-3210.
- d. Evaluation The staff agrees with the licensee's basis and, therefore, relief should be granted from the requirements of Section XI for the pump parameters as listed in the relief request. The licensee has demonstrated that with the system design, con-figuration and installation, it is impractical to obtain the measurements in the Code specified manner for these parameters.
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- e. Conclusion The staff concludes that due to the pump and system design, the relief requested should be granted. The alternate testing is imposed and should give reasonable assurance of pump operability required by the Code; therefore, the staff concludes that the i relief granted will not endanger life or property or the common defense and security of the public.
- 5. System: EDG Air Intake Diesel Generator Turbo-chargers
- a. Relief Requested Relief is requested from measuring and recording all required parameters.
. b. Code Requirements
)
Reference:
Appendix A, Pumps I c. Licensee's Basis For Requesting Relief i
This self-contained unit has no instrumentation. It is cooled
- and lubricated by the engine auxiliaries. It has no controls 1
as the correlated action of the turbine and blower is entirely i automatic. The sole measure of turbo-charger performance is the ability of the diesel generator to develop rated output. The
, diesel generator load handling ability is tested in accordance with Technical Specification requirements.
} L alternate testing is proposed.
- d. Evaluation i
The staff agrees with the licensee's basis and, therefore, relief should be granted from requirements of Section XI for the
'i. pump parameters as listed in the relief request. The licensee has demonstrated that with the system design, configuration and installation, it is impractical to obtain the measurements in the
, Code specified manner for these parameters.
l
- e. Conclusion l The staff concludes that due to the pump and system design, the relief requested should be granted. No alternate testing is imposed; however, the technical specification required diesel generator load testing should give reasonable assurance of pump operability required by the Code; therefore, the staff
- concludes that the relief granted will not endanger life or l
property or the common defense and security of the public.
- 6. SYSTEM: All Diesel Generator Engine-Driven Pumps AFFECTED PUMPS: All Pumps
- a. Relief Requested Relief is requested from taking vibration measurements directly on these pumps.
- b. Code Requirement Article IWP-4510, states that at least one displacement vibration amplitude (peak-to peak composite) shall be read during each inservice test.
- c. Licensee's Basis for Requesting Relief Meaningful vibration measurements cannot be taken on engine-mounted pumps. The overall engine vibration completely overwhelms any vibration generated by the pump. Thus, vibration measurements on these units would not identify potential or actual degradation of the pump. Vibration monitoring of the engine casing can provide information which would allow assessment of the overall engine performance and operability.
No alternative testing of the individual pumps is proposed.
Vibration measurements will be taken on the diesel engine during inservice tests. ,
- d. Evaluation The staff agrees that relief should be granted from the individual pump vibration measurement requirements of Section XI due to the equipment design.
l e. Conclusion The staff concludes that relief should be granted from taking
~ individual pump vibration readings. Vibration measurements of the diesel engine casing is imposed and should provide reason-able assurance of diesel engine operability; therefore, the staff concludes that the relief granted and additional require-ments imposed will not endanger life or property or the common defense and security of the public.
B. Valve Testing Program The licensee's IST program for the EDG auxiliary systems was examined to verify that valves, whose function is safety related, are included in the program and where practical are subjected to the periodic tests required
by the Code,Section XI. The staff's review found that these valves are tested to meet these requirements to the extent practical or relief from the requirements was requested. The licensee's basis for requesting relief from the specific valve testing requirements and the staff's evaluation and conclusion for that request is summarized below.
- 1. System: EDG Fuel Oil (Clean Oil Tank Discharge to Diesel Oil Supply Tank)
Affected Category C Check Valves 2-FO-67A, 67B, 67C, 67D, 85A, 858, 85C, and 85D
- a. Relief Requested Relief is requested from all operational testing.
- b. Code Requirement -
Reference:
Appendix A, Valves
- c. The Licensee's Basis For Requesting Relief There is no instrumentation on the piping or associated pumps and tanks. Thus, there is no way to verify, with an operational test, that the valves operate on demand. This portion of the fuel oil system of each diesel generator consists of two tanks, two pumps, and four check valves (Drawing 25203-26010). These two tanks (capacity 9.5 gallons each) are cross-connected through normally open valves 2-FO-69 and 2-F0-70. Failure of
, any one of these check valves to open would not affect diesel operability since the redundant pump and piping flow path would provide adequate return capacity. Failure of any one check valve to close would not affect diesel generator operability since the redundant check valve in each line provides backup capability. Further, even if both check valves in one line simultaneously failed, the only effect would be to allow the return piping to the diesel storage tank to drain to the clean oil tanks when the affected pump was secured. The quantity of oil held by the piping is less than 10 percent of the tank capacity. The positive displacement transfer pump in the piping j with the failed check valves would sufficiently restrict flow that accumulated diesel fuel in the clean oil tanks could still be pumped to the diesel supply tank.
1
- d. Evaluation i
The staff agrees with the licensee's basis and, therefore, relief should be granted as requested from all testing i
requirements of Section XI for the subject valves. The staff has concluded trat a valve sampling disassembly / inspection utilizing a mancal full-stroke exercise of one valve's disc is l
I
,a also an acceptable method to verify a check valve's full stroke capability. The staff imposes the following additional. .
requirements upon the licensee in order to provide assurance of an adequate disassembly sampling program. The sampling technique requires that each valve in a sample group'must be of the same design (manufacturer, size, model number, and materials of construction) and must have the same service conditions.
Additionally, at each disassembly it must be verified that the disassembled valve is capable of full-stroking and that its internals are structurally sound (no loose or corroded parts).
A different valve of each group is required to be disassembled, inspected, and manually full-stroked at each refueling until the entire group has been tested. If it is found that the disassembled valve's full-stroke capability is in question, the remainder of the valves in that group must also be disassembled, inspected, and manually full-stroked at the same outage.
- e. Conclusion The staff concludes that disassembly of these valves to manually full-stroke exercise the discs each refueling outage on a sampling basis should demonstrate proper valve operability. The staff concludes that the alternate testing proposed by the licensee plus the added requirements for the alternate testing imposed by the staff will give reasonable assurance of valve operability required by the Code and that the relief thus granted will not endanger life or property or the common defense and security of the public.
The proposed alternate testing:
One valve of each type and size will be disassembled and inspected each refueling outage.
- 2. SYSTEM: EDG FUEL OIL Affected Category B Valves 2-FO-79, 2-FO-80
- a. Relief Requested Relief is requested from measuring stroke time of these valves.
- b. Code Requirement
Reference:
Appendix A, Valves
- c. The Licensee's Basis For Requestina Relief These thermally fused quick acting valves have stroke times of less than 1 second. Measurement of these times provides no realistic information for evaluation of valve condition.
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The proposed alternate testing:
The valves will be stroke tested as required by Article IWV-3412.
The valves will be monitored during stroke testing to assure closure occurs in less than 2 seconds. Valves which~do not 4
close within 2 second will be considered inoperable.
- d. Evaluation 4
I The staff agrees with the licensee's basis and, therefore, 1
, relief should be granted fram the stroke time measurement j requirements of Section XI for these thermally fused quick t
acting valves,
- e. Conclusions The staff imposes the proposed alternate testing and concludes that the' proposed alternate testing should give reasonable I
{ assurance of valve operability required by the Code and that the relief thus granted will not endanger life or property or the l common defense and security of the public.
- 3. System: EDG Air Starting System , !
{
! Affected Category B Valves I
, 2-DG-91A, 91B, 92A, 928, 95A, 958, 96A, 968, 27A, and 278 J
- a. Relief Requested Relief is requested from measuring stroke time ,
- of these valves.
l
- b. Code Requirement 4
Reference:
Appendix A, Valves
- c. Licensee's Basis For Requestino Relief:
i
, These valves have no visible operating parts. There are no i system instruments which monitor their operation. Thus, there
- is no way to measure the stroke time of the valves. Further, l the actual stroke time of these valves is very short (less than i
i second) and measurement of stroke time would provide no ,
l realistic information for evaluation of valve condition.
! The function of these valves is to admit starting air to the ,
diesel engine and to stop air application when the engine is
( operating. The Unit 2 Technical Specification requires that the diesel generator " starts from ambient condition and accelerates j to 2 90 percent of rated speed and to 2 97 percent of rated
! voltage in 5 20 seconds." If these valves do not travel full l u
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stroke, or operate slowly, the diesel will not meet the overall operability test. Thusit reliance on this' overall operability test is appropriate to demonstrate prompt valve operation.
(( '
The proposed alternate testing:
Once per quarter, each valvd will be tested to assure proper
, operation by verifying the diesel generator meets the overall operability (starting) requirements of the Unit 2 Technical Specific'ation when started.using only one tank and one air start valve train.
- d. Evaluation The staff agrees with the licensee's basis and, therefore, relief should be granted from the stroke time measurement requirements of Section XI for these valves.
- e. Conclusions -
3 $ ,
The. staff imposes the proposed altern. ate testing and concludes that the proposed alternate testing shoUld give reasonable assurance of valve operability required'by the Code and that the relief thus granted will not endanger life or property or the common defense and security of the public.
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Based on the review summarized herein, the staff concludes that the relief granted and alternate testing imposed for Code requirements that are considered impractical give reasonable assurance that the pump and valve operational readiness intended by the Code will be sitisfied. Additionally, there is reasonable assurance ath' t. the health and safety of the public will not be endangered by operation in'tte proposed manner. Therefore, in accordance with.
10 CFR 50.55a(g)(6)(i), we find the relief requested may be granted.' The relief is authorized by law and will not endanger life or property or the common defense and security and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
Date: NOV 0 31986 Principal Contributor:
Donald Caphton, Region I l
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APPENDIX A
- 1. CODE REQUIREMENTS--PUMPS
Reference:
ASME Boiler and Pressure Vessel Code Section XI, Subsection IWP, 1980 Edition through Winter 1981 An inservice test shall be conducted on all pumps whose function is safety related, nominally once each quarter during normal plant operation. Each inservice test shall include the measurement or observation, and recording of speed (if variable), inlet pressure, differential pressure, flow rate, ;
vibration amplitude and lubricant level or pressure. Additionally, bearing temperature shall be measured during at least one inservice test each year.
- 2. CODE REQUIREMENTS--VALVES
Reference:
ASME BOILER AND PRESSURE VESSEL CODE Section XI, Subsection IWV, 1980 Edition through Winter 1981' Subsection IWV-3411 of the Section XI Code requires that Code Category A and 8 valves be exercised once every 3 months, with exceptions as defined in IWV-3412(a). IWV-3521 requires that Code Category C valves be exercised once every 3 months, with the exceptions as defined in IWV-3522. IWV-3700 contains test requirements for active and passive valves. The limiting value of full stroke time for each power operated valve shall be identified by the owner and tested in accordance with IWV-3413(a), (b), and IWV-3417(a), (b).
In the above exceptions, the Code permits the valves to be tested at cold shutdown where: ,
- 1. It is not practical to exercise the valves to the position required to fulfill their function or to the partial position during power operation.
- 2. It is not practical to observe the operation of the valves (with fail safe actuators) upon loss of actuator power.
Subsection IWV-3413(b) requires all Category A and B power-operated valves to be stroke-time tested to the nearest second or 10% of the maximum allowable owner-specified time. Additionally, all Category A valves are required to be individually leak rate tested and trended on a frequency not to exceed each 2 years in accordance with IWV-3420.
Appendix B The P& ids listed below were used during the course of this review.
System P&ID Revision Circ. and Service Water Screenwash 25203-26008, Sh. I 24 and Chlor. System Fuel Oil Systems 25203-26010 4 Circ. and Service Water, Screenwash 25203-26008 Sh. 2 10 and Chloride System Piping and Instrument Diagram Diesel 25203-26018 13 Generator Cooling, Starting Air and Lube Oil Systems Bouhdary Diagram-Emergency 25203-26126 Sh. 12 1 Diesel-Generator "A" Fuel Oil System Boundary Diagram-Emergency Diesel 25203-26126 Sh. 13 1 Generator "B" -Fuel Oil System Boundary Diagram-Diesel Air Starting 25203-26126 Sh. 14 1 System (DASS) "A" Diesel Engine Boundary Diagres* Emergency Diesel 25203-26126 Sh. 16 1 Generators "A" & "B" - Lube Oil Systems Boundary Diagram - Emergency Diesel 25203-26126 Sh. 17 1 Generator "A" & "B" - Air Cooling Systems Boundary Diagram - Emergency Diesel 25203-26126 Sh. 18 1 Generator "A" - Jacket Cooling System I
! Boundary Diagram - Emergency Diesel 25205-26126 Sh. 19 1 l
Generator "B" - Jacket Cooling System l
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