ML20080F165
| ML20080F165 | |
| Person / Time | |
|---|---|
| Site: | Prairie Island  |
| Issue date: | 01/31/1984 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20080F168 | List: |
| References | |
| TAC-53456, TAC-53457, NUDOCS 8402100358 | |
| Download: ML20080F165 (17) | |
Text
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4 UNITED STATES 8
NUCLEAR REGULATORY COMMISSION n
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WASHINGTON, D. C. 20555
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INSERVICE TESTING PROGRAM SUPPLEMENTAL SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION NORTHERN STATES POWER COMPANY PRAIRIE ISLAND NUCLEAR GENERATING PLANT, UNIT NOS. 1 & 2 DOCKET NOS. 50-28? AND 50-306 Introduction By letter dated January 4,1983, the Comission issued Amendment No. 60 to Facility Operating License No. DPR-42 and Amendment No. 54 to Facility Operating License No. DPR-60 for the Prairie Island Nuclear Generating Plant Unit Nos. I and 2.
The amendments revised the Technical Specifications implementing the inservice testing of ASME Code Class 1, 2 and 3 pumps and valves in accordance with the requirements of 10 CFR 50.55a " Codes and standards". The Safety Evaluation associated with those amendments showed that seven relief requests, i.e., 2.2, 2.3, 2.4, 2.6, 3.2.5, 3.2.15 and 3.2.21, were under review by the staff. This Supplemental Safety Evaluation is related to those seven relief requests based on additional information submitted by.the licensee's letter dated April 19, 1983 and during the appeal meeting held on February 11, 1983.
Discussion and Evaluation The NRC's letter dated April 28, 1976 to Northern States Power Company (the licensee) pointed out that the revised regulations require inservice inspection and testing to be performed in accordance with the examination and testing requirements set forth in Section XI and addenda thereto. A review of.
the 1974 edition of ASME Section XI indicated that conflicts may occur between these requirements and the Technical Specifications presently in effect for the licensee's facility.
To avoid these and future conflicts, the licensee was advised, in accordance with 10 CFR 50.55a(g)(5)(fi), to apply to the Commission for amendment of the facility Technical Specifications. Further, any such conflicting Technical Specifications should be replaced with a reference to 10 CFR 50.55a. Sample language for such Technical Specification changes was provided.
The licensee was further advised that if it m determined that conformance with certain Section XI inservice inspectiori ed testing requirements were
-impracticable, the licensee should submit information to support the l
determinations in accordance with 10 CFR 50.55a(g)(5)(fi) and (iv).
The determinations should separately identify the specific Section XI requirement.
that is impracticable for each affected component.
We indicated that the staff would evaluate each determination, and, if appropriate, grant relief pursuar. to 10 CFR 50.55a(g)(6)(1).
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/, By letter dated January 4,1983, the Comission issued Amendment Nos. 60 and 54 revising the Technical Specifications (TS) implementing the inservice testing of the ASME Code Class 1, 2 and 3 pumps and valves. The Safety Evaluation related to these amendments shows that seven relief requests submitted by the licensee remained under staff review. Subsequently in an appeals meeting held on February 11, 1983, and by letter dated April 19, 1983 the licensee submitted additional information addressing these seven relief requests. Based on our evaluation of the additional information, our determinations to grant only the remaining outstanding reliefs requested are documented below.
I.
2.2 The Licensee's Recuest for Relief. from Measuring Pump Shaft Vibration Amplituce Pursuant to Section XI, IWP-3110, -3210 and
-4500 (Relief Request No. 2)
~
Affected Comnonents l
Safety Injection Pumps 11, 12, 21 and 22, Component Cooling Pumps 11, 12, 21, I
and 22, Containment Spray Pumps 11, 12, 21 and 22, Diesel Driven Cooling Water Pumps 12 and 22, Residual Heat Removal Pumps 11, 12, 21 and 22, Centrol Room Chill Water Pumps 121 and 122 and Auxiliary Feedwater Pumps 11, 12, 21 and 22.
Code Requirement Vibration amplitude shall be measured during each inservice test, nominally at monthly intervals.
Licensee's Basis for Relief l
Not all Prairie Island pumps are equipped to measure this parameter.
In addition, the vibration amplitude is considered inferior to vibration velocity measurements as a method of determining machine condition.
l Evaluation The licensee has used ASME Publications 67-PEM-14 and 78-WA/NE-5, Vibration Tolerances for Industry, to establish alert and action ranges shown in Table 1 which are based on unfiltered velocity measurements supplemented by filtered measurements and analyses for certain cases. The staff finds these alert and action ranges acceptable since they verify that a pump is in good mechanical condition if the unfiltered surveillance test measured velocity increases above the baseline value or is above 0.3 in/sec.
Conclusion The staff agrees with the licensee's basis in that the use of vibration velocity measurements are superior to vibration amplitude measurements for monitoring pump degradation.
In addition, the proposed allowable vibration
-3 C' values shown in Table 1, combined with the surveillance procedures described in NSP's April 19, 1983 subniittal, will provide reasonable assurance of pump operability. Based on these considerations, the staff concludes that relief thus granted will not endanger life or property or the common defense and security of the public.
II. 2.3 The Licensee's Request for Relief from Instrumentation Accuracy Requirements in Section XI, IWP-4110 (Relief Request No. 3)
Affected Components Component Cooling Pumps 11, 12, 21 and 22, Diesel Driven Cooling Water Pumps 12 and 22.
Code Requirements Flow instrumentation shall be accurate to within 2%.
Licenser'3 Basis for Relief The presently installed instrumentation has an accuracy of 3% and is sufficiently accurate to detect a char.ge in pump condition.
Evaluation We agree with the licensee's basis, in that the installed flowrate instrumentation can adequately monitor this parameter.
In addition, the licensee is measuring pump differential pressure, vibration velocity and rotative speed. The staff feels that the cost and time required to replace this instrumentation scould not be justified since the increase in safety would not be significant.
Conclusion The staff concludes that flow instrumentation which is accurate to t3% will I
provide reasonable assurance of' pump operability with respect to'this parameter. Based on this consideration, we conclude that relief thus granted will not endanger life or property or the common defense and security of-the public.
I i
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III. 2.4 The Licensee's Request for Relief from Verifying Pump Operational l
Readiness as Required by Section XI, IWP-1000 (Relief Request No. 4) l Affected Components Fuel oil transfer pumps 121 and 122 supplying diesel driven cooling water (plant service water) pumps 12 and 22, diesel generator fuel oil transfer pumps 121, 122, 123 and 124.
Code Requirement The hydraulic and mechanical condition of a pump shall be determined by attempting to duplicate several parameters on a monthly basis:
rotative speed, inlet pressure, differential pressure, flowrate, bearing temperature and vibration amplitude.
Licensee's Basis for Relief A performance test on the Diesel Cooling Water or Diesel Generator Fuel Oil Transfer pumps conducted in accordance with Section XI is impractical and unnecessary for the followiag reasons:
1.
The fuel oil transfer pumps are submerged in approximately ten feet of diesel oil and are not installed with instrumentation for measuring bearing temperature or rotor vibration.
2.
Pump discharge pressure is very low because of low resistance of-the discharge line. Discharge pressure is approximately 2.0 psig as measured on 0-30 psig range gauge.
-3.
There are two fuel oil transfer pumps for each diesel engine.
Failure
]
of one transfer pump will cause cn alarm requiring start of the redur. dant transfer pump. Between the failure of one transfer pump and the start of the second (redundant) pump there is an excess!of five hours supply of fuel oi' in the day tank at the diesel engine.
4.
A flow rate test of the transfer pumps requires draining and refilling of the diesel day tank. Such draining and refilling requires opening and closing of manual valves and thus adds to chances for operator error.
As an alternative to the code requirements, the licensee test runs each fuel oil transfer pump monthly to ' verify that an adequate supply of fuel is held in the diesel engine day tanks.
In addition,'the licensee, by letter dated October'28, 1983, committed to amperage test each of the six pumps once per annum spread evenly over the year (i.e., one pump every 2 months with a scheduled tolerance of' 2 weeks). The motor current will be measured and compared to the' action ranges confirmed by the manufacturer.
If the test
i
-57 of any pump indicates a deteriorating condition, all remaining pumps will also be tested at that time. These submerged oil pumps normally draw 5-6 amperes during normal operation. The licensee's program calls for action ranges of less than 4 amperes on the low side and greater than 8 amperes on the high side. These action ranges were developed by the licensee in consul-tation with the manufacturer.
If the pump draws current outside these action ranges, the licensee declares the pump inoperable and corrective action will be taken.
Evaluation and Conclusion The staff agrees with the licensee that verifying the pump operational readiness as required by Section XI, IWP-1000 is impractical and the licensee has submitted adequate information to support this determination. We agree with the licensee that the increased test frequency in this case will not improve the level of safety substantially to warrant placing the plant in a less safe condition during the more frequent testing periods.
On this basis, the staff concludes that the alternate test methods will give reasonable assurance of pump operational readiness as intended by the code and therefore relief may be granted.
In granting this relief, we also conclude that the plant safety margin is not reduced and it does not endanger public health and safety.
IV. 2.6 The Licensee's Relief Request from Determining the Pump Hydraulic Conditions as Required by Section XI, IWP-3100-2 (Relief Request No. 24)
Affected Components Diesel driven cooling water pumps 12 and 22.
Component Cooling Water Pumps 11 and 12.
Code Requirement The 1974 Code requires measurement of inlet pressure, differential pressure (dp), flow-rate and speed in variable resistance systems.
The measurement of these parameters must meet the acceptable alert and required action ranges outlined in IWP-3100-2.
Licensee's B sis for Relief f
1 System design does not allow performance of hydraulic tests at specific reference points. Because of the numerous system loading combirations possible, it is not practical to reestablish -the exact reference point for
-62 the pump test. Because a repeatable reference point cannot be reestablished for each test, the inaccuracies in determining the pumps hydraulic conditions and code allowable variances in these conditions (flow and dp) compound the allowable ranges of operation when both flow and op are compared together.
The pump flow and pump suction and discharge pressure are recorded. The pump dp is then plotted against flow to determine a " point" on the pump curve. This pump curve was developed from vendor supplied performance and preoperational test data.
The acceptable range will be between 90.1% and 103.5% of the pump curve. The alert ranges will be changed from 85.3% to 90.1% (low values) or 103.5% to 105% (high values) of the pump curve. The required action raage will be the same as the alert ranges.
By letter dated October 28, 1983, the licensee withdrew the relief request for the component cooling water pumps 11 and 12.
The specified code limits will be applied when determining the pump hWaulic conditions for the com-ponent cooling water pumps 11 and 12.
Evaluation We agree with the licensee that the system hydraulic conditions are such that the flow and the pressure drop across the pumps are constantly oscillating caused by changing hydraulic loads on the system.
The changing hydraulic loads are due to the numerous heat exchangers connected to the system with constantly changing coolant demands (cooling water system provide coolant to component cooling water heat exchangers, air chillers, hydrogen coolers for turbine generators, etc.).
In adj! tion the overall hydraulic loads vary with plant conditions from one test period to the next, preventing the establishment of a specific reference point on the pump characteristic curve that could be used during each monthly test.
To improve the hydraulic measurement accuracies of these pumps without disrupting the plant normal operating conditions would require the installation of 2 test loops, one for each pump, that would serve to bypass these varying hydraulic loads.
The installation of these test loops involves modifying 24 inch diameter pipe systems requiring the shutdown of both units and removal of the fuel from the core.
In addi-tion, the fuel in the spent fuel pool would also have to be removed or a temporary cooling system would have to be installed for the decay heat removal at the spent fuel pool while the component cooling water system is being modified. On this basis, we agree with the licensee that such plant modifi-cations are judged to be impractical.
l l
The diesel cooling water pumps have excess capacity in that the flow required by FSAR to bring the plant to cold shutdown is 77% of pump flow capacity curve used to monitor pump performance.
In the case of the design basis accident, the flow required by these pumps is 67% of the pump flow capacity curve.
The proposed action range of 85.3%, including 3% for instrument
< error, is well above the pump flow capacity required for safe operation.
Therefore we find that lowering the action range from 90.1 to 85.3 for the diesel cooling water pumps is acceptable.
In addition, by letter dated October 28, 1983, the licensee committed that a concurrence will be obtained in writing from the pump manufacturer (Worthing-ton Manufacturing Co. Pump Division) confirming that the proposed action ranges are satisfactory. The licensee also informed the staff that the concurrence will include a verification that adequate pump capacity can be sustained within the proposed action ranges for a 30 day operating period.
The two diesel driven cooling water pumps are standby pumps that provide coolant during time periods when the normal-power supply is lost to the normal motor driven cooling water pumps.
Each diesel driven cooling water pump, capable of providing adequate coolant to both units must provide cooling flow during those periods until the normal power supply is restored to the motor driven cooling water pumps. Experience shows that such normal power outage periods have lasted for only several hours and have never lasted more than a single day. On this basis we conclude that sustaining the proposed action ranges for a 30 day operating period is acceptable.
The documentation related to this commitment will be in place oy December 31, 1983'and may be subjected to an Inspection and Enforcement Audit.
Raising the action ranges from 103.5% to 105.0% will provide reasonable assurance of pump operability with respect to this parameter.
Conclusion The staff concludes that proposed action ranges of less than 85.3% or greater than 105% for the diesel coolino pumps are acceptable. This conclusion is based on the determination that the cost and time reqaired to modify these systems to meet the action ranges given in the Section XI Code are impractical and the proposed action ranges by the licensee will not involve a significant reduction in the existing level of safety.
On this basis, we conclude that relief from the Code may be granted since such action will not endanger public health and safety.
-8 V.
3.2.5 The Licensee's Relief Request from Stroke Time Testing Power
~0perated Valves per Section XI, IWV-3410(c) (Relief Request No. 9)
Affected Components Unit 1 Unit 2 SV-33133 Cig Water to 121 Safeguards Travel Scrn SV-33992 21 Post LOCA H Containment Vent 2
SV-33134 Clg Water to 122 Safeguards Travel Scrn SV-33993 22 Post LOCA H Containment Vent 2
SV-3346412 DC1 Water Pump Air Motor SV A CV-31683 21 TD Aux Fd Pmp 011 Cir Wtr Init SV-33465 12 DCI Water Pump Air Motor SV B CV-31684 22 TO Aux Fd Pmp Oil Cir Wtr Init SV-33466 22 DC1 Water Pump Air Motor SV A SV-33467 22 DCI Water Pump Air Motor SV B CV-31954 D1 Diesel Generator Air Start A CV-31955 D1 Diesel Generator Air Start B CV-31956 D2 Diesel Generator Air Start A CV-31957 D2 Diesel Generator Air Start B SV-33990 11 Post LOCA H2 Containment Vent SV-33991 12 Post LOCA H2 Containment Vent CV-3142312 DC1 Water Pump Jckt Clr Outlet CV-31457 22 DC1 Water Pump Jckt Clr Outlet CV-31682 12 TD Aux Fd Pmp Oil Clr Clg Wtr Init CV-31681 11 TD Aux Fd Pmp 011 Clr C1g Wtr Init SV-33728 121 Cont Room Water Chlr Mtr Clr SV-33766 122 Cont Room Water Chlr Mtr Clr Co,de Requirement IWV-3410(c)
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-9 For Power Operated Valves (1) The limiting value of full stroke time of each power operal J valve shall be specified by the owner.
(E) The stroke time of all power operated valves shall be measured to the nearest second or 10% of the maximum allowable stroke time, whichever is less, whenever such a valve is full-stroke tested.
(3) If an increase in stroke time of 25% or more from the previous test for valves with stroke times greater than ten seconds or 50% or more for valves with stroke times less than or equal to ten seconds is observed, test frequency shall be increased to once each month until corrective action is taken, at which time the original test frequency shall be re-sumed.
In any case, an abnormality or erratic action shall be reported.
Licensee's Basis for Relief The power operated valves are fast acting lacking indication at the controlling switch, therefore stroke timing described in IWV-3410(c) will not provide the repeatibility necessary to measure component operability.
Alternate Inspection Testing SV-33133 and SV-33134 - Cooling Water to 121 Safeguards Travel Screen. Valves will be coarse timed using a watch second hand or other device to determine valves open in less than five seconds. However, the licensee, after further discussions with the licensing Project Manager, has agreed to reduce the J
coarse screening criteria from five to two seconds. Opening will be determined by increased pressure downstrean of the valve.
Evaluation The staff agrees that meeting the stroke timing criteria of the Code is impractical for these valves. We do agree that the use of a two second "Codrse screening" Criteria is adequate to allow measurement that would be used to take necessary corrective action.
Conclusion The staff concludes that the alternate testing agreed to by the licensee will provide reasonable assurance of valve operability.
Based on this con-sideration, we conclude that relief thus granted will not endanger life or property.or the common defr.1se.
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Alternate Inspection Testing SV-33464, 33465, 33466 and 33467 - Diesel Cooling Water Pump Air Motor Solenoid Valves.
Valves are part of the diesel cooling water pump system whose overall opera-bility is determined by start timing and this timing will be used to determine the operability of the solenoid valves. Because the SVs are paired to the diesel, one could fail and the diesel would still start. The Air Motor exhaust will be checked to verify that the individual soltaoids are operable.
Evaluation ind Conclusion These valves actuate within less than one second and are totally enclosed so that the valve position cannot be visually checked.
In addition, because of noise in the area, a change in valve position through sound cannot be deter-mined adequately. As an alternative, the licensee verifies the proper opera-tion of these valves by the monthly diesel cooling water system test to assure that the 30 second start time limit specified in Section 10.4 of the USAR is met. The 30 second start time limit includes a 15 second time delay to allow for the actuation of the low pressure setpoint and 15 seconds to allow the diesel engine to come up to speed. By letter dated October 28, 1983, the licensee committed to monitor the air exhaust from these solenoid valves quarterly to assure a full open position.
In addition, the valves undergo an annual preventative maintenance inspection where the valves are cleaned, lubricated and all moving parts are inspected for wear. On this tasis, the staff agrees with the licensee's alternative testing to assure valve opera-bility. Since valve testing is difficult during operation in that the valve stem motion cannot be observed, the staff has judged that this relief may be granted. The alternative testing does assure adequate operation of these 4
valves. Based on these considerations, we conclude that relief thus granted will not endanger life or property or common defense.
Alternate Inspection Testing CV-31954, 31955, 31956 and 31957 - Diesel Generator Air Start Control Valves.
Valves are part of the diesel generator system whose overall operability is determined by start timing and this timing will be used to determine the operability of the control valves. Because~the CVs are paired to the diesel, one cculd fail and the diesel would still start. The stroking of these valves will be observed locally to ensure that both valves function together.
Evaluation and Conclusion These valves actuate within less than one second and the operation is diffi-cult to observe by the available personnel during the monthly diesel system test. This is due to the remote valve location with respect to the diesel engine control panel and operators performing the test cannot observe the valve
l s ' '! motion.
In addition, because of noise in the area, a change in valve position through sound cannot be determined adequately. As an alternative, the licensee verifies the proper operation of these valves by the monthly diesel engine test to assure that the 10 second start time limit is met.
In addition, the valves undergo an annual preventative maintenance inspection tnat includes valve cleaning, lubrication and inspection of all moving parts for wear. By letter dated October 28, 1983, the licensee has agreed to include the quarteriy two second coarse screening test criteria as both valves for each diesel generator are actuated simultaneously.
On this basis, the staff agrtes with the licensee's alternative testing to assure valve operability. Since valve testing is difficult during operation in that the valve stem motion cannot be observed, the staff has judged that this relief may be granted. Based on these considerations, we conclude that relief thus granted will not endanger life or property or common defense.
Licensee's Basis for Relief SV-33990 and 33991 - Post LOCA H Containment Vent.
2 Valves operating time cannot be measured. Valves open on a signal from a limit switch on a motor operated valve, the operating time of the SV is in milliseconds, (about two orders of magnitude less than the MV cycling time) and the SV's moving parts are totally enclosed, and the SV is not easily accessible. Therefore, because the valve cycling time is shorter than the actuating time and there is no means to tell when the valve has closed, stroke timing would be a meaningless measure of operability. However, testing will verify air flow through the valve has stopped when the valve is operated.
Evaluation The staff agrees with the licensee's basis. Since these valves are difficult to assess and the licensee has stated that the motion of the valve is diffi-cult to determine directly, the staff feels that this relief should be granted.
The alternate testing proposed should verify that the valves are operating.
Conclusion The staff concludes that the alternate testing proposed will provide reasonable assurance of valve operability.
Based on this consideration, we conclude that relief thus granted will not endanger life or property or the common defense.
Licensee's Basis for Relief CV-31423 and 31457 - Diesel Cooling Water Pump Jacket Cooler Outlet.
These valves operate only when the diesel cooling water pumps are operi. ting and the valves open 7::tomatically through the startup circuit of these pumps,
- 12 i making it difficult to measure valve stroke time. After further discussions with the project manager, the licensee has agreed to stroke time these valves in accordance with the Code requirement (IWV-3410(c)).
However, the licensee has requested relief from the stroke time test frequency (IWV-3410(a)) from the 3 month interval (i.e., code requirement) to once annually. The stroke time test of these valves will be included as part of the annual preventative maintenance inspection of the diesel cocling water pumps.
Valve operability is tested monthly and if the valve fails to open within 10 seconds or does not remain in its proper position during operation, an alarm will sound in the control room requiring corrective action by the operator.
In addition, these valves will be observed for smooth operation quarterly. As discussed in the licensee's response dated October 28, 1983, smooth operation will include verification that the full stem travel occurs within approximately one second.
To perform the stroke time test quarterly would require 100% of the balance of plant operators and would thus interfere with the normal operator's duties that must be attended to during plant operations. Stroke timing these valves is complex, requiring a large number of operators to monitor many parameters during the starting sequence of the diesel cooling water pumps that automatically actuate the valves.
Evaluation and Conclusion The staff agrees with the licensee that measuring valve stroke time quarterly in this case is impractical, since the valves are operationally tested monthly and, if ti.e valves to open within the prescribed 10 seconds limit, an alarm will sound in the control room requiring corrective action by the operator.
On this basis, we conclude that decreasing the f eauency of stroke time testing of these valves will not reduce the assurance of valve operability.
Based on these considerations we conclude that relief thus granted will not endanger life or property or common defense.
Licensee's Basis for Relief CV-31682 and 31681 - Aux Feedwater Pump Oil Cooler Cooling Water Inlet Valve.
Valves receive an open signal from the pump start circuitry which is done remotely.
Valves will be coarse timed, using a watch second hand or other device, to determine valves open in less than five seconds.
Opening will be determined by local observation of valve movement. However the licensee, after further discussions with the licensing project manager, has agreed to monitor these valves to a two second coarse' screening time criteria as an alternative to the stroke timing requirement of the code.
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,a Evaluation and Conclusion The staff agrees that meeting the stroke timing criteria of the code is impractical for these valves. We do agree that the use of the two second coarse screening time criteria is adequate to allow measurements that would be used to take necessary corrective actions. On this basis, we conclude that the alternate testing agreed to by the licensee will provide reasonable assurance of valve operability. Based on this consideration, we conclude that relief thus granted will not endanger life or property or common defense.
Licensee's Basis for Relief SV-33728 and 33766 - Control Room Water Chiller Motor Cooler.
Valves are open/close solenoid valves. The valve stem is not accessible and the valve operating time is on the order of milliseconds.
Noise in the area prevents hearing the valve operating. One Control Room Chiller is operating at all times and these chillers are alternated weekly.
Failure of the SV to open will be indicated by a rise in motor temperature. This failure would then be known by a control room alarm.
Evaluation The staff agrees with the licensee in that performing the stroke timing tests on these solenoid valves is impractical, particularly since excessive noise prevents hearing the valves operate. Additionally, these valves are cycled as a minimum on a weekly basis and, if a failure occurs, an alarm is sounded in the control room. Anthough gradual valve degradation may not be evident, this frequency of testing provides added assurance of the opera-bility of these valves.
Conclusion The staff concludes that the licensee's operating procedures, combined with the indicated alarms, will provide reasonable assurance of the operability of thr:se valves and that relief thus granted will not endanger life or property or the common defense.
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/r VI. 3.2.15 Licensee's Relief Request from Stroke Time Valves IWV-3410(c) geliefRequestNo.22)
Affected Components Unit l' CV-31923 11 Post LOCA H Vent to Annulus 2
CV-31929 12 Post LOCA H Vent to Annulus 2
Unit 2 CV-31924 El Post LOCA H Vent to Annulus 2
CV-31930 22 Post LOCA H Vent to Annulus 2
Code Requirements Stroke time for power operated valves shall be measured in accordance with IWV3410(c).
Licensee's Basis for Relief The control valves are designed to modulate open and close to control venting rate of containment to the shield building. The valve position and stroking time are a function of the difference between an air loader (controller) signal and the position of the valve. This difference cannot be consistently re-produced, therefore stroke tining would be a meaningless measure of valve operability. The valves wiil be exercised at cold shutdown by stroking the valve and observed maximum, half maximum, and minimum flow as indicated on flow neters. The flow measured will be the flow that exists between the containment and shield buildings as generated by the dp as it exists at the time of the test. This will verify the ability of the CV to control the venting of the containment.
Evaluation The staff does not agree with the licensee that the stroke' timing of these valves is impractical or meaningless. The staff considers the stroke tining requirements of the Codes as a valuable inservice testing tool to' assist in identifying unacceptable valve degradation or improper ad.justments, packing.
overtightness, torque switch setting, etc., prior to complete' failure of ~a valve assembly to perforn its required function under system challenging conditions.
-15
Conclusion The staff concludes that meeting the stroke time requirements of the Code is neither impractical nor meaningless and therefore, this relief is denied.
VII. 3.2.21 Licensee's Relief Request from the Streke Timing Requirements of IWV-3410(c) - (Relief Request No. 53)
Affected Components Unit 1 CV-31381 Cooling Water From 11 Component Cooling Heat Exchanger CV-31411 Cooling Water From 12 Component Cooling Heat Exchanger CV-31785 122 Control Room Chiller Condenser Cooling Water Outlet CV-31769 121 Control Room Chiller Condenser Cooling Water Outlet Unit 2 CV-31383 Cooling Water From 21 Component Cooling Heat Exchanger CV-31584 Cooling Water From 22 Component Cooling Heat Exchanger Code Requirements Stroke time testing of power operated valves shall be performed in accordance with IWV-3410(c). Refer to SER paragraph 3.2.5.
Licensee's Basis for Relief The CV are designed to modulate to control functions. The amount of valve-movement and time for valve movement is a function of the difference between input signal (desired condition) and measured signal (actual condition). 'The plant is not able to reproduce this difference consistently, therefore stroke timing would be meaningless. At the frequency specified in IWV-3410(a), the ability of the control valve to stroke smoothly will be locally verified. The signal to stroke the valve will be the adjustment of the temperature control setpoint.
- a Evaluation The staff does not agree with the licensee that the stroke timing of these valves is impractical or meaningless. As stated in the licensee's basis, manual control of these valves is possible via the temperature control set-point. Additionally, the staff considers the stroke timing requirements of the Code as valuable inservice testing tools which help to identify un-acceptable valve degradation or improper adjustments (packing overtightness, torque switch settings, etc.) prior to the complete failure of a valve assembly to perform its required function under system challenging conditions.
Conclusion The staff concludes that meeting the stroke time reauirements of the Code is neither impractical nor neaningless and, therefore, this relief is denied.
Environmental Consideration We have determined that this action does not authorize a change in effluent types or total amounts nor an increase in power level and will not result in any significant environmental impact. Having made tnis determination, we have further concluded that this action involves an action which is insigni-ficant from the standpoint of environmental impact and, pursuant to 10 CFR 951.5(d)(4), that an environmental impact statement or negative declaration and environmental impact appraisal need not be prepared in connection with this action.
Conclusion We have concluded, based on the considerations discussed above, that (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, and (2) such activities will be conducted in compliance with the Commission's regulations and the issuance of this action will not be inimical to the common defense and security or to the health and safety of the public.
Date: JAN 31 1984 Prinicpal Contributor:
Joel Page l
Table 1 HASIS F0p. REQtJEST FOR RET.II# #2 Allowable Rangen for Vibration Test Quantities Reference j
Alert Action Velocity Range Range 0<V
<0.15 I"/sec V
>V
+ 0.2 I"/sec V
>v
+ 0.3 I"/sec r, -
t r,
t r,
0.15 '"/sec i V 0.d"/sec V
>V
+ 0.2 I"/sec V
>V
+ 0.3 '"/sec 0.3
"/sec < V < 0.6
"/sec V
>V
+ 0.2 I"/sec V
>V
+ 0.3
"/sec f
I"/sce < V,1< 0.8 I"/sec V
>V
+ 0.2 I"/sec V
>V
+ 0.3 I"/sec 0.6 1
1 Def ini t ir as :
V = reference velocity measurement (unfiltered)
V = surveillance test velenity. measurement (unfiltered)
.t The vibra t ion reference valuen are the val.ms of vibration af ter initial installation or rework of the pump whth the
- pump being in good mechanical condition.
If the V increases :o a higher value f rom the base value with the pump in good mechanical condit ion or is
^
above - 0.$ (or a pump
"/sec, a vibration analysis will he conducted documentirig the frequency and amplitude that would he analyzed.
This ' analysis will. determine wh ither the vibration is f rom the puinp or other sources.
Some examples of such an analysin are:
1 ) TIw sa fe ty injection, residual heat removal ~, anil contalument spray pumps operate at minimum flow during the surveillance testing.
Illnimum flow condit *una causes higher vibration levels.
2-) The cooling wa ter pumps have a righ t angle drive.which couples the pump to the diesel engine and the near strive is-a major contributor-to the higher velocity reading.
- 3) The component cooling ' pump, under certa in plant conditions, operates under low flow conditions and this again leadu to higher. than normal vibration levels.
Experience has demonstrated that measurement of axial vibration on the end cover of the pump can tell the operator of possible misalignment of the hearing. The enil cover is a - re la t ively thin section and ampilfles the actual vibration.
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