ML20246F473
| ML20246F473 | |
| Person / Time | |
|---|---|
| Site: | Rancho Seco |
| Issue date: | 02/28/1989 |
| From: | Bonney R, Cook T, Rockhold H EG&G IDAHO, INC. |
| To: | NRC |
| Shared Package | |
| ML20246F466 | List: |
| References | |
| CON-FIN-A-6812 EGG-NTA-8402, NUDOCS 8905120258 | |
| Download: ML20246F473 (71) | |
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EGG-NTA-8402
. February 1989 TECHNICAL EVALUATION REPORT Infeho PUMP AND VALVE INSERVICE TESTING PROGRAM National RANCHO SECO NUCLEAR GENERATING STATION Eng/neering Docket Number 50-312 Laboratory Managed by the U.S.
Degnment f "glg H. C. Rockhold ofEnergy
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}4gac5_ Prepared for the U.S. NUCLEAR REGULATORY COMMISSION 7- work perfommt urcer DOE Contract No. DE AC07 76/D01570 ,
890512O238 890504 PDR E ADOCK 05000312 PDC
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, EGG-NTA-8402 s
TECHNICAL EVALVATION REPORT PUMP AND. VALVE INSERVICE TESTING PROGRAM I RANCHO SECO NUCLEAR GENERATING STATION Docket Number 50-312-R. Bonney T. L. Cook H. C. Rockhold.
Published February 1989 Idaho National Engineering Laboratory EG&G Idaho, Inc.-
Prepared for the U.S. Nuclear Regulatory Commission Washington, D. C. 20555 Under DOE Contract No. DE-AC07-761D01570 FIN No. A6812 m
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l AFSTRACT This.EG&G Idaho, .Inc. report presents the results of our evaluation of the Rancho Seco' Nuclear Generating Station Inservice Testing Program for safety-related pumps and valves.
FOREWORD This report is. supplied as part of the " Review of Pump and Valve Inservice Testing Programs for Operating' License Reactors" being conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor
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Regulation, Mechanical Engineering Branch, by EG&G Idaho, Inc., Mechanical Systems Evaluations.
The U. S. Nuclear Regulatory Comm.ission funded the work under the 4
authorization B&R 920-19 05-02-0, FIN No. A6812.
Docket Number 50 312 i
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. CONTENTS ABSTRACT .............................................................. ii FOREWORD .............................................................. ii
- 1. INTRODUCTION ..................................................... 1 4
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.2. SCOPE ............................................................ 3
- 3. PUMP TESTING PROGRAM ............................................. 7-3.1 Pump Instrumentation ....................................... 7 3.2 Pump Pressure and Flow Rate Measurements .............. .... 10 3.3 Pump Vibration and Bearing Temperature Measurements ........ 18 1
3.4 Pump Mi scell aneous Requi rements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 4 VALVE TESTING PROGRAM ............................................ 25 4.1 All Systems ................................................ 25 4.1.1 Safety and Relief Valves ........................... 25 4.1.2 Rapid Acting Power Operated Valves ...........:..... 26 4.1.3 Power Operated Valves Tested During Cold Shutd'own .. 27 4.1.4 Containment Isolation Valves ....................... 28
.. 4.2 Re a c t o r Co ol a nt Sys t em . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4.2.1 Category B Valves .................................. 29
'4.2.2 Category C Valves .................................. 30 4.3 Makeup and. Purification System ............................. 30 4.3.1 Category A Valves .................................. 30 1 4.3.2 Category A/C Valves ................................ 34 I 4.4 Decay Heat Removal System .................................. 35
.' 4.4.1 Category A Valves .................................. 35 4.4.2 Category C Valves .................................. 36 4.4.3 Category A/C Valves ................................ 39 l
4.5 Reactor Building Spray System .............................. 42 l i
l 4.5.1 Category C Valves .................................. 42 1
1 1 4.6 High Pressure feedwater Heater System ...................... 45
. 1 4.6.1 Category C Valves .................................. 45 l iii l l
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4.7 Coolant Radwaste System ....................................
46 4.7.1 Category A Valves .................................. 46' .
4.8 Emergency Diesel Generator System .......................... 47 4.8.1 Category B Valves .................................. 47 4.8.2 Category C Valves .................................. 47 APPENDIX A--VALVES TESTED DURING COLD SHUTD1WNS ....................... 49 APPENDIX B--PalD LIST ................................................. 57 APPENDIX C--IST PROGRAM ANOMALIES IDENTIFIED DURING THE REVIEW ........ 61 et a
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, TECHNICAL EVALUATION REPORT PUMP AND VALVE INSERVICE TESTING PROGRAM RANCHO SECO NUCLEAR GENERATING STATION l
- 1. INTRODUCTION Contained herein is a technical evaluation of the pump and valve inservice testing (IST) program submitted by the Sacramento Municipal Utility District for their Rancho Seco Nuclear Generating Station.
The lice'nsee's IST Program was reviewed to verify compliance of proposed tests of safety-related pumps and valves with the requirements of the ASME Boiler and Pressure Vessel Code (the Code),Section XI, 1980 ,
Edition through Winter 1981 Addenda. Any IST program revisions subsequent to those noted above are not addressed in this technical evaluation report (TER). Required program changes, such as revised or additional relief requests oc the deletion of any components from the IST Program, should be submitted to the NRC under separate cover in order to receive prompt attention, but should not be implemented prior to review and appro~ val by the NRC.
In their IST Program, Sacramento Municipal Utility District has requested relief from the ASME Code testing requirements for specific pumps and valves and these requests have been evaluated individually to determine if the criteria in 10 CFR 50.55a for granting relief is met for the specific pumps and valves. This review was performed utilizing the acceptance criteria of the Standaro Review Plan, NUREG-0800, Section 3.9.6, and the Draft Regulatory Guide and Value/ Impact Statement titled " Identification of
.' Valves for Inclusion in Inservice Testing Program". The IST Program testing requirements apply only to component testing (i.e., pumps and valves) and are not intended to provide the basis to change the licensee's current technical specifications for system test requirements.
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l l Section 2 of this report presents the scope of this review. .
Section 3 of this report presents the Rancho Seco Nuclear Generating -
Station relief requests and EG&G's evaluations and conclusions regarding these requests _for the pump testing program. Similar information is presented in Section 4 for the valve testing program.
Category A, B and C valves which are exercised during cold shutdowns and refueling outages and meet the requirements of the ASME Code,Section XI are discussed in Appendix A.
A listing of P&ID's used for this review is contained in Appendix B.
Inconsistencies and omissions in the licensee's IST program noted during the course of this review are listed in Appendix C. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
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- 2. SCOPE The EG&G Idaho review of the Rancho Seco Nuclear Generating Station inservice testing (IST) program for pumps and valves was begun in October, 1987. The program initially examined was Revision 3, dated June 25, 1987, which identified the licensee's proposed testing of safety-related pumps and valves in the plant systems listed in Appendix B.
The licensee's proposed IST program was reviewed by locating and highlighting the components on the appropriate system P&lDs and determining their function in the system. Then the licensee's proposed testing was evaluated to determine if it was in compliance with the ASME Code, i Section XI, requirements. During the course of this review, questions and comments were made pertaining to unclear or potential problem areas in the licensee's IST. program. These were transmitted to the licensee in the form.
of a request for additional information (RAI) which served as the agenda for the working meeting between the licensee, the NRC, and the EG&G reviewers.
Each pump and valve relief request was individually evaluatedI to
, determine if the licensee had clearly demonstrated that the Code i requirements are impractical or present a hardship without a compensating increase in safety for the identified system components, and to determine if the proposed alternate testing would provide reasonable assurance of component operability. Where the licensee's technical basis or alternate testing was insufficient, the licensee was requested -to clarify the relief request. The system P&lD was also examined to determine whether the instrumentation necessary to make the identified measurements is available.
If, based on the unavailability of adequate instrumentation or the reviewers
,' experience and system knowledge, i*. was determined that it may not be possible or practical to make the measurements identified in the licensee's IST program, a question or comment was generated requesting clarification.
For pumps, it was verified that each of the seven inservice test quantities of Table IWP-3100-1 were measured or observed. For those test quantities that were not being measured or observed quarterly in accordance with the Code, it was verified that a request for relief from the Code l
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j requirements had been submitted. If testing was not being performed in
, l r accordance with the Code and a relief request had not been submitted, the licensee was requested to explain the inconsistency in the RAI.
i The review of the proposed testing of valves verified that all appropriate ASME Code testing.for each individual valve is performed as required. The proposed testing was evaluated to determined if all valves j that were judged to be active Category A, B, and/or C, (other than safety and relief valves) are exercised quarterly in accordance with IWV-3410 or i 3520. If any active safety-related valve is not full-stroke exercised I quarterly as required, then the licensee's justification for the {
deviation, either in the form of a cold shutdown justification or a relief request, was examined to determine its accuracy and adequacy. The '
proposed alternate testing was also evaluated to determine its compliance with the Code requirements.
Safety-related safety valves and relief valves, excluding those that perform only a' thermal relief' function, were confirmed to be' included in the IST program and tested in accordance with IWV-3510.
For valves with remote position indication, the reviewer confirmed that the valve remote position indication is verified in accordance with IWV-3300. The reviewer verified that the licensee had assigned limiting values of full-stroke times for all power operated valves in the IST program, as required by IWV-3413. For valves having a fail-safe-actuator, the reviewer confirmed that the valve's fail-safe actuator is tested in accordance with IWV-3415.
l Each check valve was evaluated to determine if the proposed testing would verify its ability to perform its safety function (s). Extensive system knowledge and experience with other similar facilities is employed to determine whether the proposed tests would full-stroke the check valve disks open or verify their reverse flow closure capability. If there was any doubt about the adequacy of the identified testing, questions were included in the RAI. !
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further' evaluation was performed on all valves in the program to determine that the identified testing could practically and safely be conducted as described. If the licensee's ability to perform the testing was in doubt, a question was formulated to clarify the suspected proolem.
Once all the components in the licensse's IST program had been
. identified on the P&lDs and evaluated as described above, the P&lDs were examined closely by at least two trained and experienced reviewers to-identify any additional pumps or valves that may perform a safety function. The licensee was asked to reconcile any components that were ider.tified bf this process which were not included in the IST program.
Also, the list of systems included in the licensee's program was compared to a system list in the Draft Regulatory Guide and Value/ Impact Statement titled, " Identification of Valves for Inclusion in Inservice Testing Programs". Systems that appear in the Draft Regulatory Guide list but not in the licensee's program were evaluated and, if appropriate, questions were added,to the RAI.
Additionally, if the reviewers suspected a problem with a specific or a general aspect of the licensee's IST program, questions were included in the RAI to clarify those areas of doubt. Some questions were included for the purpose of allowing the reviewers to make conclusive statements in the TER.
i At the completion of the review, the RAI was transmitted to the licensee. These questions were later used as the agenda for the working meeting with the licensee on January 6 and 7, 1988. At the meeting, each <
question and comnient was discussed in detail and resolved as follows:
- a. The licensee agreed to make the necessary IST program corrections or changes to satisfy the concerns of the NRC and their reviewers,
- b. The licensee provided additional information or clarification about their IST program that satisfied the concerns of the NRC and their reviewers, and no program change is required.
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- c. The item remained open for the licensee to investigate further ,
and propose a solution to the NRC.
- d. The item remained open for further. investigation by-the NRC.
- e. The item remained open for further investigation and discussion by both-the NRC and-the-licensee.
The-licensee responded to the RAI and the working meeting discussions
.in their revised program resubmittal, revision 4 dated January 28, 1988.
The program chniges were identified and evaluated to determine whether they'were acceptable and if not, they were added to the items that !
,. remained open from the meeting.
This TER is based on information contained in the submittals, and on information obtained during the working meeting which took place during the review process.
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- 3. PUMP TESTING PROGRAM The Rancho Seco Nuclear Generating Station IST program submitted by Sacramento Municipal Utility District was examined to verify that all pumps.
. that are included in the program are subjected to the periodic tests required by the ASME Code,Section XI, except for those pumps identified below for which specific relief from testing has been requested and as summarized in Appendix C. Each Sacramento Municipal Utility District basis for requesting relief from the pump testing requirements and the EG&G reviewer's evaluation of that request are summarized below.
3.1 Pumo Instrumentation 3.1.1 Relief Reauest.
The licensee has requested relief from the pump instrumentation full-scale range as required by Section XI, Paragraph IWP-4120 for high pressure safety injection pumps P-238A and P-2388, makeup pump P 236, decay ,
heat removal pumps P-261A and P-261B, reactor building spray pumps P-291A and P-291B, and boric acid transfer pumps P-705A and P-705B and has proposed to utilize the installed pump suction pressure process instrumentation.
l 3.1.1.1 Licensee's Basis for Recuestina Relief- "The installed l suction pressure gauge of a pump is generally sized to accommodate the maximum pressure it would experience under normal or emergency conditions.
In many cases, this results in an instrument range that exceeds the Code ;
requirement since, under test conditions, high suction pressures are typically not experienced. Strict Code compliance would require the installation of temporary gauges that would not be suitable for routine or emergency pump operation."
" Suction pressure measurements serve two primary functions. First they provide assurance that the pump has an adequate suction head for proper operation. Secondly, the suction pressure is used to determine the pump differential pressure."
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1 ;g . .c "For the determination of' suction h.ead, the accuracy and range
- requirement is overly restrictive. Since, in most cases, plant. pumps are
- provided with a considerable margin of suction head, accuracy on the order of 0.5 to 0.75 psig should be adequate."
"When used in' determining pump differential pressure, 'the accuracy of ,
the suction pressure measurement has little or no effect on the calculation I I
since, generally, the pump discharge pressure is higher than the suction J pressure by 2 orL 3 orders of magnitude." } '
"When meltsuring the suction pressure of a pump, in lieu of meeting the instrument range requirement..of IWP-4120, instruments will be installed such j that the accuracy meets the requirements set forth below:
Accuracy will be at least plus or minus 0.5 psi The accuracy of the differential pressure calculation will be limited to plus or minus 2 percent of the differential pressure calculated value.
i Accuracy of the suction pressure instrument will be better than plus or minus 0.5 percent of the calculated differential pressure."
3.1.1.2 Evaluation--The installed suction process instrumentation should provide a reasonable means to measure the Code required parameters during Section XI pump testing as the accuracy of these instruments is equivalent or better than the Code requirements.
Based on the determination that the Code requirements are impractical, and considering the licensee's proposed alternative of utilizing installed suction process instrumentation with an accuracy equivalent to or better than the Code requirement, and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
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- l. 3.1.2 Relief Reauest.
1 The licensee has requested relief from the pump instrumentation full-scale range as required by Section XI, Paragraph IWP-4120 for vibration measurements for all pumps in the program and has proposed to utilize l ,
digital instrumentation to measure pump vibration.
3.1.2.1 Licensee's Basis for Reauestino Relief- "The commercially available state-of-the art instruments used. for measuring pump vibration do not provide range selections that guarantee adherence to the range limitations per Subarticle IWP-4120. Ranges are typically expanded beyond the multiple of three as required by.the Code and, in the case of the digital instruments used currently at Rancho Seco, the instrument is self scaling over a broad range of measurements."
"The accuracy of instruments used to measure vibration are generally based on the' actual measured value and is unrelated to.the instrument range. The instrument accuracies are typically approximately plus or minus 5 percent of the reading. This is considerably better than that specified by the Code (plus or minus 5 percent FS) that can be as much as plus or minus 15 percent of the reading."
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" Commercially available instrumentation will be used to measure pump vibration with an overall reading accuracy equal to or better than that required by IWP-4100 (15 percent)."
3.1.2.2 Evaluation--Utilizing digital self-scaling vibration instrumentation is a reasonable alternative to the Code requirement that l
this instrumentation have a maximum scale range three times the reference value. The accuracy of this instrumentation is equivalent to or better than !
the Code requirements. I Based on the determination that the Code requirements are impractical, and considering the licensee's proposed alternative of utilizing digital self-scaling vibration instrumentation with an accuracy equivalent to or better than the Code requirement, and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
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3.2 Pumo pressure and Flow Rate Measurements
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3.2.1 Relief Reauest.
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The licensee has requested relief from the Section XI, Paragraph IWP-3110 requirement that differential pressure and flow rate measurements shall be readily duplicated during subsequent inservice tests and has proposed to utilize pump curves to compare differential pressure and flow rate for all pumps in the program.
3.2.1.1 Licensee's Basis for Reauestino Relief- " Operating experience has shown that it is not always practical to duplicate points of operation with the available flow control systems and instrumentation.
Efforts to exactly duplicate the reference values may not be possible or ~
would require excessive valve manipulation which could result in damage to valve components or excessive personnel exposure."
"During pump reference tests, a reference pump curve may be established or the manufacturer's pump curve confirmed. In lieu of duplicating a specific reference flowrate during subsequent inservice tests, a flowrate (Qa) will be obtained and recorded along with the corresponding differential pressure (dPa). The differential pressure value (dPa) will then be compared to the theoretical differential pressure corresponding to the measured ,
flowrate (Qa) on the pump curve. The acceptance criteria of Table IWP-3100-2 will be applied as appropriate."
3.2.1.2 Evaluation--Utilizing a pump curve to compare differential pressure and flow rate for pump inservice testing is acceptable as a pump curve is an infinite set of fixed sets of reference values. The pump curve defines what corresponding differential pressure would be for pump flow rate when the pump is known to be in good working order. The licensee has committed to applying table IWP-3100-2 acceptance criteria to measured values, thus a hydraulically degrading pump should be detected.
Because of the design of these systems, compliance with the Code requirements is impractical. Conformance with the Code would be possible only if these systems were substantially redesigned.
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Based on the determination that the Code requirements are impractical, the licensee's proposed utilization of pump curves for comparison of flow rate and differential pressure for all pumps in the program, and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
. 3.2.2 Relief Recuest.
The licensee has requested reliaf from the Section XI, Table IWP-3100-2 limits for the Alert-range (high) value and for the Required-action range (high) value for differential pressure and flow rate measurements for all pumps in the program and has proposed to raise the Alert-range (high) limits to be 105% to 110% and to raise the Required-action range (high) limit to be greater than 110% of reference value for differential pressure and flow rate -
measurements.
3.2.2.1 Licensee's Basis for Recuestina Relief- "The requirement to declare a pump inoperative when a test parameter (flowrate or differential pressure) exceeds the reference value by 3 percent is'not
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technically justified, sound engineering judgement, nor acceptable plant operating practice for the following reasons:
4 Indiscriminately declaring safety system pumps inoperative could result in excessive and unneeded testing of other plant safeguard systems and components. Such testing could ultimately detract from the overall reliability of plant safety systems. In addition, unwarranted testing unnecessarily adds to the burden of the operating staff and dilutes efforts focused on the performance of their primary duties. Such testing also results in unnecessary radiation exposure.
The case where a test parameter exceeds the reference value does not indicate pump degradation. it may merely signify that the reference value is probably on the lower side of the statistical scatter of the l test data and the specific test in question is on the upper side. Note that the reference values are subject to the same elements of statistical error associated with any other individual test.
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The 3-percent limitation is overly restrictive when compared to the ,
accuracy of the instrumentation used to gather the test data as ,
required by Paragraph IWP-4110 (plus or minus 2 percent).
Power plant operating systems are not configured in a way that allows for the accuracy and precision of the testing needed to consistently and reliably provide the repeatability needed to meet this requirement.
This requirement provides no additional measure of reliability to the equipment."
"The acceptance criteria of Table IWP-3100-2 will be utilized, unless otherwise noted, with the following exceptions:
(a) The Required-Action Range (HIGH) will be greater than 110 percent of the reference value for test quantities of flowrate and differential pressure; and (b) The Alert Range (HIGH) will be between 105 to 110 perceni of the reference value for test quantities of flowrate and differential pressure."
3.2.2.2 Evaluation--Table IWP-3100-2 identifies the pump '
para.neters to be monitored during pump tests and the allowable ranges of I those parameters. The licensee s proposal to raise the Alert-range (high) limits from 105% to 110% and raise the Required-action range (high) limit to be greater than 110% of reference values for differential pressure and flow rate measurements for all pumps in the program has not provided sufficient
- information to demonstrate that pump degradation will be detected prior to the pump being unable to meet its design basis pressure and flow requirements. To resolve this issue, the licensee should provide the staff with information that identifies the specific pumps with which difficulties occur while being tested in accordance with the requirements of Section XI.
The licensee should also include information that discusses the cause/s) of the data scatter encountered during pump tests and provide a basis tc show that significant degradation will not affect required pump operability if the proposed methodology is utilized.
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Based on the determination that the Code requirements are practical, that the licensee has not demonstrated the impracticality of the Code
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requirements, nor demonstrated that the proposed alternate limits will provide pump protection at least equivalent to the requirements of the Code,
.. relief should not be granted as requested.
. 3.2.3 Relief Reauest.
The licensee has requested relief from the Section XI, Table IWP-3100-1 requirement of measuring pump static inlet pressure prior to pump start for all pumps in the program and has proposed to measure only dynamic inlet pressure for operating pumps for inservice testing.
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3.2.3.1 Licensee's Basis for Reauestino Relief- "If the pumps being tested are in operation as a result of plant or system.needs, it is unreasonable and impractical to reconfigure system lineups simply to provide for measurement of the static inlet pressure."
" Inlet pressure prior to pump startup is not a significant parameter needed to evaluating pump performance or material condition."
"When performing a test on a pump that is already in operation due to system requirements, inlet pressure will only be measured during pump operation."
3.2.3.2 Evaluation--Because of the design of these systems, compliance with the Code requirements is impractical. Stopping an operating pump or reconfiguring a system valve lineup to measure static inlet pressure
," will not provide a significant parameter needed for evaluating pump hydraulic performance.
Based on the determination that the Code requirements are impractical and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
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1 3.2.4 Relief Reouest.
- The licensee has requested relief from the Section XI, Paragraph IWP-3100 requirement that flow rate be measured for makeup pump P-236 and I 1
high pressure injection pumps P-238A and P-238B quarterly and has proposed 1 that all required parameters be measured on a refueling outage frequency.
3.2.4.1 Licensee's Basis for Reauestina Relief- "The only practical method of full flow testing these pumps is to inject water into the Reactor Coolant System requiring initiation of fiP injection and pumping k water from thb BWST. This would cause transients in pressurizer level and reactor power and is considered to be imprudent during power operation. In addition, injection of cold water into Reactor Coolant System during j operation would cause thermal shocking of the injection nozzles. During I cold shutdown, the HP Injection Isolation motor-operated valves are I deenergized closed and the pumps are electrically disabled to prevent low temperature over-pressurization. Consequently, the only practical method of '
testing is'to circulate water through the minimum flow line for each pump.
Because of this, the maximum flowrate achievable is approximately 20-percent of the nominal rated pump flow. Note that there is no flow measuring instrumentation installed in the minimum flow circuit."
"During partial-flow testing, the region of the pump curve in which the testing will be performed is near shutoff head and flow rate readings are not necessarily meaningful for the viewpoint of trending."
"Since the HP injections pumps stand idle except for periods of
, testing, significant inservice degradation is unlikely."
"These pumps will be tested quarterly with the fixed resistance of the minimum flow line. During these tests, all appropriate pump operational parameters will be measured and evaluated with respect to Table IWP-3100-2 and associated relief requests with the exception of flowrate."
"During each refueling outage, each pump will be tested under nominal full-flow conditions and all required parameters will be measured, including fl owra t e . "
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3.2.4.2 Evaluation--Measuring the makeup and high pressure injection pumps' flow rate while operating on the minimum flow recirculation line is not a meaningful test for pump operability as flow rate is only approximately twenty percent of rated pump flow. Testing these pumps by utilizing injection during power operatinn is not practical as this could result in pressurizer level perturbations and subsequent reactor shutdown.
Testing during cold shutdown could result in a reactor coolant system (RCS) low temperature overpressurization. Measuring all required pump parameters on a refueling outage frequency when a full flow path to the RCS is ,
available is a reasonable alternative to the Code requirements of quarterly measurement of pump flow rate. Because of the design of this system, compliance with the Code requirements is impractical and conformance with the Code would only be possible if the makeup and purification system was substantially redesigned. I Based on the determination that the Code requirements are impractical, and considering the licensee's proposed alternative of measuring all required pump parameters on a refueling outage frequency and all required pump parameters except pump flow rate quarterly, and the burden on the
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licensee if the Code requirements were imposed, relief may be granted as requested.
3.2.5 Relief Reauest.
The licensee has requested relief from the Section XI, Table IWP-3100-1 requirement of measuring pump inlet pressure for nuclear service raw water pumps P-472A and P-472B and diesel fuel oil transfer pumps P-108A, P-108B, P-10BC, P-108D, P-888A, P-888B, P-888C, and P-88BD and has proposed to
,' calculate a single inlet pressure for these pumps based on the submergence depth of the pumps.
3.2.5.1 Licensee's Basis for Recuestino Relief- "These pumps are submerged and, as such, have inlet pressures corresponding to the water level in the spray pond basin or oil level in the fuel oil tanks. There is no practical mechanism for measurement of suction (inlet pressure). Also, changes of level during testing is insignificant."
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" Inlet pressure will be calculated from the height of liquid above the '
pump suction prior to or during each test, but only once per test." >
3.2.5.2 Evaluation--Because of the design of these systems, compliance with the Code requirements is impractical. Calculation of the inlet pressure for the nuclear service raw water and diesel fuel oil transfer pumps from the static head of the medium in which the pumps reside provides a reasonable alternative for measuring pump inlet pressure, as conformance with the Code would only be possible if the diesel fuel oil transfer and nuclear service raw water systems were substantially redesigned. Since these head levels remain essentially constant during the tests, one measurement of the head level should be sufficient for calculation of inlet pressure.
Based on the determination that the Code requirements are impractical, and considering the licensee's proposed alternative calculation utilizing suction head level, and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
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Relief Reauest.
The licensee has. requested relief from the Section XI, Table IWP-3100-1 requirement of measuring pump flow rate for nuclear service raw water pumps P-472A and P-472B and nuclear service cooling water pumps P-482A and P-482B and has proposed to calculate flow rate for the nuclear service raw water j pumps. Flow rate instrumentation for both of these systems will be installed prior to or during the next Refueling Outage, No. 7.
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. 3.2.6.1 Licensee's Basis for Recuestina Relief- "There is no installed instrumentation for measuring the flowrate in any of the above piping systems."
" Appropriate flowrate measuring instrumentation will be installed in these systems prior to or during the next Refueling Outage, No. 7 (Loading Core Cycle 8). In the interim the following will apply.
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'For pumps P-472 A & B, flowrate will be derived by measuring the l
. spray header pressure and determining flowrate from curves of )
spray header pressure vs. flowrate empirically developed during )
the Rancho Seco Startup Testing Program. l For pumps P-482 A & B, it is assumed that the system resistance is fixed and only pump differential pressure will be measured and evaluated."
l 3.2.6.2 tvaluation--Because of the design of these systems, compliance wfth the Code requirements is impractical. However, the licensee will install the necessary flow rate instrumentation for both of these systems prior to or during the next Refueling Outage, No. 7, thus, utilizing -
system flow curves to determine nuclear service raw water pump flow rate and measuring nuclear service cooling water pump differential pressure in a fixed resistance flow path are reasonable interim alternatives to the Code requi remen,ts.
BasedonthedeterminationthattheCoderequirementsareimp[ractical, and considering the licensee's future installation of flow rate instrumentation, and the burden on the licensee if the Code requirements were imposed, interim relief may be granted as requested until completion of Refueling Outage, No. 7.
3.2.7 Relief Recuest.
The licensee has requested relief from the Section XI, Paragraph .
IWP-4600 requirement that flow rate be measured utilizing a rate or quantity meter and the Paragraph IWP-3500(a) requirement that diesel fuel oil transfer pumps P-108A, P-108B, P-108C, P-108D, P-888A, P-888B, P-888C, and P-888D be operated at least 5 minutes prior to test data measurement. The licensee has proposed that flow rate be calculated f- day tank level change over time and that test data measurements be taken when these pumps' flow and pressure conditions have stabilized following pump start.
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- _ _ _ _ _ _ _ _ _ _ _ _ - - _ - - _ - _ _ _ _ _ _ _ _ _ _ _ _ - _ _-_ - _ _ - _ _ _ _ _ . _ _ _ _ _ _ _ _ _ - _ _ _ _______--_____a
3.2.7.1 Licensee's Basis for Recuestina Relief- *The only .
mechanism of measuring flowrate for these pumps is by measuring the increase ,
of oil level in the day tanks and relating it to the respective pump operating time. There is insufficient available volume in the day tanks to allow the pumps to run for five minutes prior to taking data without significantly affecting test accuracy."
"During testing of these pumps, data will be taken as soon as flow and pressure conditions have stabilized following pump start."
3.2.7.2 Evaluation--A five minute pump run prior to obtaining Code required data for the diesel fuel oil transfer pumps is not practical due to the lack of available day tank volume. Recording data after pump flow and pressure conditions have stabilized following pump start is a ~
reasonable alternative to the Code requirement of a five minute pump run.
Calculation of pump flow rate from day tank level change over time is a reasonable alternative to the Code requirement that flow rate be measured utilizing a rate or quantity meter as this int.trumentation is not installed in the diesel fuel oil transfer system. Because of the design of this system, compliance with the Code requirements is impractical and conformance with the Code would only be possible if the diesel fuel oil transfer system was substantially redesigned.
Based on the determination that the Code requirements are impractical, hnd considering the licensee's proposed alternative of measuring day tank level change over time when pump flow and pressure has stabilized following pump start, and the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3 Puro Vibration and Bearina Temperature Measurements 3.3.1 Relief Recuest. 1
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The licensee has requested relief from the Section XI, Paragraph IWP-4510 requirements for vibration amplitude measurement and measurement location for all pumps in the program and has proposed to utilize vibration velocity measurements taken in two locations.
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_ _ - - - - - _ _ - - _ - - - - - - i
3.3.1.1 Licensee's Basis' for Recuestina Relief- " Measuring vibration in velocity units rather than displacement is an industry accepted method considered to be more sensitive to small changes that are indicative of developing mechanical problems. Velocity measurements detect not only high-amplitude vibration, characteristic of major mechanical problems, but low-amplitude vibration caused by misalignment, imbalance, or bearing wear."
"It is impractical to search for the direction with the largest deflection and procedurally return to that location on successive tests.
Also, the direction of maximum deflection may change with pump age and material condition, thus, this is not necessarily a conservative nor proper practice."
, "At the option of the plant staff, pump vibration measurements may be taken and trended in either displacement or velocity units. Acceptance criteria for velocity measurements will conform to Table 2.1."
" Vibration measurements will be taken in two pre-established mutually perpendicular directions in a plane perpendicular to the rotating shaft."
" Table 2.1: Allowable Ranges of Vibration Levels (ips)*
Ref. Vib. Acceo. Rance Alert Action Rec.
<0.15 0 - 0.3 0.301 - 0.45
> 0.45 0.15 - 0.3 0 - 0.45 0.451 - 0.7 > 0.7 0.3 - 0.6 0 - 0.7 none > 0.7 0.6 - 0.7 0 - 0.7 none > 0.7
- Limits based on ASME Technical Paper 78-WA/NE-5. All units in inches per second (ips)"
3.3.1.2 Evaluation--Pump bearing degradation results in increased bearing noise at frequencies 5 to 100 times the rotational frequency of the pump. These high frequency bearing noises would not produce a significant increase in pump vibration displacement measurements and could go undetected. However, the high frequency noises would result in relatively large changes in pump vibration velocity measurements which could permit corrective action prior to catastrophic failure of the bearing. Because of the high frequencies of the vibrations associated with the pump bearings, 19
vibration velocity measurements are generally much better than vibration displacement measurements in monitoring the mechanical condition of pumps -
and detecting pump bearing degradation.
The advantages of using vibration velocity instead of displacement for monitoring the mechanical condition of pumps, with the exception of reciprocating pumps, are widely acknowledged in the industry. The use of' pump vibration velocity signatures over a wide frequency range can provide a great deal of information about pump mechanical condition that would not be j obtained by using vibration displacement readings.
Measuring pump vibration in velocity units rather than displacement will give more useful information to evaluate pump mechanical condition. _
However, the licensee has not provided enough technical information in his basis for relief to determine if relief should be granted. The vibration velocity testing guidance of'ASME document OM-6, draft 10, is an acceptable alternative to the vibration monitoring required by Section XI, provided that all of the OM-6 guidance for vibration velocity monitoring is _ utilized and contained in the relief request. -
Based on the determination that pump vibration velocity measurements provide more information to evaluate pump mechanical condition and to detect bearing degradation than the Code required displacement readings and considering the licensee's proposal to measure pump vibration velocity, relief may be granted, provided that the licensee utilizes all of the ASME OM-6, draft 10 vibration velocity measurement guidance.
3.3.2 Relief Reauest.
The licensee has requested relief from the Section XI, Paragraph IWF-3100 requirement that pump vibration shall be measured during each pump test for diesel fuel oil transfer pumps P-108A, P-108B, P-108C, P-108D, P-888A, P-8888, P-888C, and P-888D.
3.3.2.1 Licensee't Basis for Reauestina Relief "Each of these pumps is submerged within.its respective fuel oil tank thus, the bearing housings are inaccessible for vibration measurements."
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_ _ _ _ _ _ _ _ - - _ - - - _ - _ _ _ _ - - - - - I
, ,3.3.2.2 Evaluation--As the diesel fuel oil transfer pumps are submerged within the diesel fuel oil tanks, a vibration measurement for
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these pumps is impractical. Because of the design of this system, compliance with the Code requirements is impractical and conformance with
. the Code would only be possible if the fuel oil transfer system were substantially redesigned.
Based on the determination that the Code requirements are impractical, and considering the burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
3.3.3 Relief Recuest.
The licensee has requested relief from the annual bearing temperature measurement requirements of Section XI, Table IWP-3100-1 for all pumps in the IST program.
3.3.3.1 Licensee's Basis for Reauestino Relief- "Many of the bearings of the centrifugal pumps included in the Rancho Seco IST _ Program i are water cooled -- cooling water supplied from the flowstream or auxiliary closed cooling water systems. Thus, bearing temperature measurements are ,
highly dependent on the temperature of the cooling medium and not necessarily indicative of bearing condition." ~
"The data associated with bearing temperatures taken at one-year intervals provides little statistical basis for determining the incremental degradation of a bearing or any meaningful trending information or correlation."
" Vibration measurements are a significantly more reliable and meaningful indication of an imminent or existing bearing failure. It is highly unlikely that such a condition would go unnoticed during routine pump operation or surveillance testing. Other indications of bearing problems include audible noise, reduced pump performance, seal failure, unusual vibration, increased mot'or current, etc."
21
l l l "The gain from taking bearing measurements, which in most cases must be ,
done locally using portable instruments, cannot offset the cost in terms of .
dilution of resources, distraction of operators from other primary duties, ,
I excessive operating periods for normally idle pumps, and personnel radiation exposure."
3.3.3.2 Evaluation--The annual bearing temperature measurement is an unreliable method of detecting bearing failure and deletion of this i measurement will not adversely affect the licensee's pump monitoring program. Many of the bearings of the centrifugal pumps included in the Rancho Seco IST Program are water cooled, thus, bearing temperature measurements may be significantly influenced by the temperature of the cooling medium and may not necessarily be indicative of bearing condition.
Experience has shown that when serious degradation of pump bearings occurs, bearing temperatures remain relatively constant until just prior to the actual bearing failure. With the bearing temperature measurement being taken on an annual basis, the likelihood of detecting a bearing failure l during the test is minimal. Elimination of the requirement to measure bearing temperature would not impact the effectiveness of the pump monitoring program. Further, the licensee has proposed to utilize pump vibration velocity measurements which should be able to detect degrading bearings. Bearing temperatures taken at one year intervals provides little
- tatistical basis for determining the incremental degradation of a bearing or any meaningful trending information or correlation. The burden on the licensee if the Code requirements were imposed would not be justified by the limited information that would be provided about pump bearing mechanical I condition.
Based on the determination that the measurement of bearing temperature
,' provides little meaningful data, is a burden to the licensee, and does not contribute significantly to the effectiveness of the pump monitoring l program, relief may be granted as requested.
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3.4 Pumo Miscellaneous Requirements 3.4.1 Relief Reauest.
The licensee has requested relief from the Section XI, Paragraph l IWP-3230(a) requirement that the frequency of testing be doubled if deviations fall within the Alert Range of Table IWP-3100-2 for diesel fuel oil transfer pumps P-888A, P-8888, P-888C, and P-888D.
3.4.1.1 Licensee's Basis for Recuestina Relief- "Since there is no practical mechanism for draining the day tanks, these pumps are tested by draining down the day tank with diesel generator operation and subsequently measuring the tank fill rate to determine pump flow rate. Thus, testing -
these pumps requires diesel generator operation. Should a pump enter an -
alert range, the increased test frequency per IWP-3230(a) would require additional starts and operation of the related diesel generator. Such additional testing is considered to be detrimental to diesel generator reliability."
"Since the pumps are only operated during testing, there is no credible
, mechanism of pump deterioration between tests. Thus increasing the test frequency is of little value."
3.4.1.2 Evaluation--Since these diesel fuel oil transfer pumps operate only during periods of diesel generator operation, requiring tneir testing frequency to be doubled if their test parameter (s) enter the Alert Range of Table IWP-3100-2 will result in unnecessary diesel generator operation.
Based on the determination that the Code requirements are impractical and burden on the licensee if the Code requirements were imposed, relief may be granted as requested.
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- 4. VALVE TESTING PROGRAM The Rancho Seco Nuclear Generating Station IST program submitted by Sacramento Municipal Utility District was examined to verify that all valves that are included in the program are subjected to the periodic tests required by the ASME Code,Section XI and the NRC positions and guidelines.
. The reviewers found that, except as noted in Appendix C or where specific relief from testing has been requested, these valves are tested to the Code requirements and the NRC positions and guidelines. Each Sacramento ;
Municipal Utility District basis for requesting relief from the valve testing requtremer'.s and the reviewer's evaluation of that request are i summarized below and grouped according to system and valve category.
4.1 All Systems 4.1.1 Safety and Relief Valves
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4.1.l.1 Relief Reauest. The licensee has requested relief from testing safety and relief valves according tsSection XI, Paragraplh IWV-3510 and has proposed to test these valves according to ANSI /ASME OM-1-1981.
4.1.1.1.1 Licensee's Basis for Reauestina Relief- " ANSI /ASME OM-1-1981 - Requirements for Inservice Performance Testing of Nuclear Power Plant Pressure Relief Devices, was developed to supersede the requirements of Subsection IWV-3510. This standard is more definitive and better suited to operational testing than is ASME/PTC 25.3 which is referenced in IWV-3510."
4.1.1.1.2 Evaluation--Utilizing ANSI /ASME OM-1-1981 to test safety and relief valves is a current NRC accepted alternative to the IWV-3510 referenced ASME/PTC 25.3-1976.
l Based on the licensee's proposed alternative safety and relief valve testing, relief from the Code requirements may be granted as requested.
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4.1.2 Raoid Actino Power Ooerated Values
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r 4.1.2.1 Relief Reauest. The licensee has requested relief from the corrective action requirements of Section XI, Paragraph IWV-3417 for rapid acting power operated valves (including turbine stop/ throttle valves TV-1, TV-2, TV-3, and TV-4) and has proposed to verify and record stroke times as being less than two seconds.
4.1.2.1.1 Licensee's Basis for Reauestina Relief- "The stroke times of most solenoid and the Main Turbine Stop/ Throttle Valves are rapid and stroke time measurements are subject to considerable variation due to j test conditions as well as operator reaction time."
"When exercising these valves with stroke times measuring less than 2 seconds, stroke time measurements will be recorded but will only be verified
- l to be less than two seconds. The requirements of IWV-3417 will not apply." '
4.1.2.1.2 Evaluation. The licensee has demonstrated that it is not practi, cal to obtain accurate measurements of the stroke times for power operated valves that normally stroke in two seconds or less. Vari (bilityof stroke times of rapid acting power operated valves is primarily a function of the timing method and is not a reliable indicator of valve degradation.
Based on the design of these valves the staff has concluded that assigning a maximum stroke time of two seconds is a reasonable alternative to the Code requirements for these valves.
The licensee should assign a maximum limiting stroke time of two seconds to these valves and is not required to trend stroke time in accordance with IWV-3417(a). Should the stroke time for these valves exceed ;
two seconds, the licensee must perform corrective action as required by
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IWV-3417(b).
Based on the impracticality of complying with the Code requirements, the licensee's proposed alternative testing, and the burden on the licensee if the Code requirements were imposed, relief may be granted as discussed 4
above.
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4.1.3 Power Ooerated Valves Tested Durino Cold Shutdown
, 1 4.1.3.1 Relief Reouest. The licensee has requested r,elief from the increased exercising frequency requirement of Section XI, Paragraph
,. IWV-3417(a) for category A and category B valves identified as being tested 4 on a cold shutdown frequency (see Appendix A of this report) and has proposed to evaluate .the valve's condition and demonstrate that the valve is _
operable prior to the plant returning to power operation. !
I 4.1.3.1.1 Licensee's Basis for Reouestino Relief- " Strict adherence to this re'quirement, as stated, could require a plant shutdown or operation under unusual conditions each' month for testing until it is determined that the valve is operating satisfactory and has not undergone significant degradation or some corrective maintenance action is performed -
to correct the condition."
"Since valve stroke time would be less than the maximum allowable, it '
would continue to be considered operable and thus, corrective maintenance, alongwiththeaccompanyingtimeandpersonnelexposurecosts,majnotbe warranted or justified."
"If valve testing during Cold-Shutdown should result in required increased test frequency per IWV-3417, the valve condition shall be .
evaluated and the valve demonstrated to be operable prior to the plant returning to power operation. This action is in lieu of increased test frequency required per IWV-3417."
4.1.3.1.2 Evaluation--The licensee's basis for requesting relief from the increased test frequency requirements of Section XI for those valves that are specifically identified for testing only during cold shutdowns is not adequate. The Code requires an increased frequency of tests to assure continued operability of the degraded valves. Valves that are specifically identified for testing only during cold shutdowns and refueling outages that are found to have exceeded the allowable change in stroke time and cannot be tested at the increased frequency should be repaired and demonstrated operable prior to being required for plant operation. '
27 u_______._ _ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ ___ ._ ___ _ _ _ _
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Since the licensee has not demonstrated that the Code requiremen,ts are impractical, relief should not be granted as reouested. ,
4.1.4 Containment Isolation Valves 4.1.4.1 Relief Reauest. The licensee has requested relief from valve leak rate testing for containment isolation category A and A/C valves according to Section XI, Paragraphs IWV-3423 through 3425 (see item 6 of Appendix C of this report) and has propo',ed to leak rate test these valves in accordance with the requirements of 10 CFR 50, Appendix J and IWV-3426 and 3427.
4.1.4.1.1 Licensee's Basis for Reauestino Relief- "Due to the configuration of the system piping and components, in many cases individual leakage rate tests are impractical. In these cases it is customary to perform tests with the test volume between valves in series or behind several valves in parallel paths."
"In those cases where individual valve testing is impractical, valves will be leak tested simultaneously in multiple valve arrangements and a maximum permissible leakage rate will be applied to each combination of valves. Test results from tests of multiple valve combinations will be evaluated in accordance with IWV-3426 and IWV-3427."
4.1.4.1.2 Evaluation--Leak rate testing these containment isolation valves in accordance with 10 CFR 50, Appendix J requirements and performing analysis of leakage rates and the corrective action of IWV-3426 and 3427 should assure valve leak tight integrity as required by the Code.
,' This is a current acceptable NRC alternative to performing valve leak rate testing in accordance with IWV-3421 through IWV-3427 requirements. Some of these containment isolation valves cannot be individually leak tested due to system design and piping configuration and must be tested in a multiple valve lineup as permitted by Appendix J requirements.
Based on the impracticality of complying with the Code required test method and the licensee's proposed alternative testing, relief from the Code requirements may be granted as requested.
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4.2 Reactor Coolant System 4.2.1 Cateaory B Valves j 4.2.1.1 Relief Reauest. The licensee has requested relief from )
exercising power operated relief valve (PORV) PSV-21511 according to 4 i
Section XI Paragraph IWV-3412 and has proposed verifying valve operability by functionally testing the valve during cold shutdown and bench testing / full-stroke exercising the valve on a refueling outage frequency.
4.2.1.1.1 Licensee's Basis for Reauestina Relief- "This valve requires system pressure to open. Thus, opening while installed requires the use of reactor coolant system pressure. This could subject the -
associated system and piping components to undesirable transients. Removal of the valve during each cold shutdown would be an unwarranted burden on the plant staff."
"During each Reactor Coolant System cooldown, this valve will, be functionally tested with the Block Valve (HV-21505) Closed. During each refueling, PSV-21511 will be full-stroke exercised via bench testing."
4.2.1.1.2 Evaluation--The main disk of this valve operates in response to the pilot valve, which operates when a solencid valve opens, either due to RCS pressure or manual operation. The main disk cannot be exercised during power operation or cold shutdown as this could depressurize and void the reactor coolant system. Operating the solenoid valve with the main disk isolated by the block valve during cold shutdown will functionally test the control circuit and pilot valve of the PORV for low temperature overpressurization conditions without depressurizing the RCS. Removing this valve from the system on a refueling outage frequency and bench testing the main disk will full-stroke exercise the main valve disk and is a reasonable alternative to the Code requirements.
Based on the impracticality of complying with the Code' required testing frequency, and the licensee's proposed alternative testing method and frequency, relief from the Code requirements may be granted as requested.
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4.2.2 Cateaory C Valves .
4.2.2.1 Relief Reauest. The licensee has requested relief from -
exercising reactor internals vent check valves RIVVWX, RIVVWZ, RIVVXW, i RIVVXY, RIVVYX, RIVVYZ, RIVVZW, and RIVVZY according to Section XI, Paragraph IWV-3521 and has proposed to verify valve operability by ;
full-stroke exercising these valves on a refueling outage frequency. .
4.2.2.1.1 Licensee's Basis for Recuestino Relief- "These valves are located on the reactor core support assembly and exercising is
( impossible without vessel disassembly-normally performed only during refueling outages."
"Each valve will be manually exercised during each refueling outage."
4.2.2.1.2 Evaluation--These valves cannot be exercised during power operation or cold shutdown because they are located in the reactor-vessel and manual exercising is necessary to verify operability. Compliance with the Code required testing frequency would be burdensome since.this j
would require quarterly plant shutdown, cooldown, and reactor head removal. '
Based on the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested.
4.3 Makeuo and Purification System 4.3.1 Cateaory C Valves
, 4.3.1.1 Relief Recuest. 'The licensee has requested relief from exercising discharge to reactor inlet loop A check valves SIM 037 and SIM-041'and discharge to reactor inlet loop B check valves SIM-049 and SIM-050 according to Section XI, Paragraph IWV-3521 and has proposed to verify valve operability by full-stroke exercising these valves on a refueling outage frequency.
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4.3.1.1.1 Licensee's Basis for Reouestino Relief- "The only practical method of exercising these valves is to inject water into the Reactor Coolant System via the Makeup and/or HP Injection Pumps. For all valves, except SIM-037, this would require initiation'of HP Injection and I
pumping water from either the BWST or the CBAT. This would cause transients in pressurizer level and reactor power and is considered to be imprudent during power operation. In addition, injection of cold water into the Reactor Coolant System during operation would cause thermal shocking of the injection nozzles. Valve SIM-037 is partial - stroke exercised to the open direction during normal operation of the Makeup System; however system flowrate is generally less than the 500 gpm required for stroking the valve to its fully opened position based on design flow conditions."
. "During cold shutdown, the HP Injection Isolation motor-operated valves and pumps are closed and electrically disabled to prevent low-temperature over pressurization. Cold shutdown testing is thereby precluded."
" Valve SIM-037 will be partial-stroked to the open position in conjunction with the normal operation of the Makeup System and vedified to close at cold shutdown by handwheel operation. Each of these valves will be full-stroke exercised during each refueling outage."
4.3.1.1.2 Evaluation--Valve SIM 037 (see item 7 of Appendix C of this report) cannot be full-stroke exercised during power operation as the makeup pump cannot develop sufficient exercising flow. Valves SIM-041, SIM-049, and SIM-050 cannot be full-stroke exercised during power operation because the resultant injection of higher concentration boric acid could cause a reactor shutdown. These valves cannot be full-stroke exercised during cold shutdown since this could result in low temperature l
overpressurization of the RCS. Compliance with the Code required testing frequency would be burdensome since this would require quarterly plant shutdown, cooldown, and reactor head removal.
Based on the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested. I 31
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! 4.3.1.2 Relief Reauest. The licensee has requested relief from ,
exercising concentrated boric acid tank (CBAT) to makbup and high pressure, injection pumps suction check valves BWS-019 and BWS-044 and borated water ,
storage tank (BWST) to makeup and high pressure injection pumps suction check valves SIM-043 and SIM-052 according to Section XI, Paragraph IWV-3521 and has proposed to verify valve operability by full-stroke exercising these valves on a refueling outage frequency.
4.3.1.2.1 Licensee's Basis for Recuestina Relief- "The only method of opening these valves during plant operation is to inject water from the Makeup or HP Injection Pumps into the Reactor Coolant System via the Pressurizer Level Control Valve or the RCP seals or via the minimum flow recirculation line to the Makeup Tank. Due to the highly concentrated boric acid solution in these tanks, injecting this water would cause undesirable changes in RCS boric acid concentration resulting in reactor power transients or difficulty in maintaining constant boric acid concentration due to over-concentration of the Makeup Tank."
"During cold shutdown, recirculating solution from the Concentrated Boric Acid or Borated Water Stroage Tanks would result in over-concentration ;
of the' Makeup Tank and significantly increase the time and difficulty of the plant startup."
"Each of the four (4) valves will be full-stroke exercised during each refueling outage."
4.3.1.2.2 Evaluation--Valves BWS-019, BWS-044, SIM-043, and SIM-052 cannot be full-stroke exercised during power operation as the resultant injection of higher concentration boric acid could cause a reactor
- shutdown. These valves cannot be full-stroke exercised during cold shutdown as the resultant injection of higher concentration boric acid would result in delay of plant startup due to the time required to decrease the plant higher boric acid concentration to startup concentration. Compliance with the Code required testing frequency would be burdensome sir.ce this would require quarterly plant shutdown and time consuming boric acid changes.
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Based on the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested.
4.3.1.3 Relief Reauest. The licensee has requested relief from exercising makeup pump discharge check valve SIM-002 and high pressure injection pumps discharge check valves SIM-045 and SIM-058 according to Section XI, Paragraph IWV-3521 and has proposed to verify valve operability by full-stroke exercising these valves on a refueling outage frequency.
4.3.1.3.1 Licensee's Basis for Reauestina Relief- "The only method of full-stroke exercising these valves is to inject water from the.
respective pump into the Reactor Coolant System. For valves SIM-045 and SIM-058, this would require initi6 tion of HP Injection and pumping water from the BWST. This would cause transients in pressurizer level and reactor power and is considered imprudent during power operation. During cold shutdown periods, injection is. precluded due to low-temperature pressurization concerns and associated procedural restrictions that require disability of pumps and valves in the injection paths." [
" Normal operation of the Makeup Pump and quarterly testing of the HP Injection Pumps demonstrate operability via a partial-stroke exercise (less than the 500 gpm required for full-stroking) of each valve. During this time, the flowrate is restricted by letdown and RCP Seal Water System demand."
"Each valve will be partial-stroke exercised during normal Makeup Pump operation or quarterly pump testing. During each refueling outage all three valves will be full-stroke exercised."
4.3.1.3.2 Evaluation--Valve SIM-002 cannot be full-stroke exercised during power operation as the makeup pump cannot develop sufficient exercising flow. Valves SIM-045 and SIM-058 cannot be full-stroke exerc'ised during power operation because the resultant injection of higher concentration boric acid could cause a reactor shutdown. These valves cannot be full-stroke exercised during cold shutdown since this could 33
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restit in low temperature overpressurization of the RCS. Compliance with j the Code required testing frequency would be burdensome since this would require quarterly plant shutdown, cooldown, and reactor head removal. .
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Based on the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested.
I 4.3.2 Cateoory A/C Valves l
4.3.2.1 Relief Recuest. The licensee has requested relief from exercising discharge to reactor inlet loop A check valves SIM-036 and SIM-040 and discharge to reactor inlet loop B check valves HV-23801 and j SIM-047 according to Section XI, Paragraph IWV-3521 and has proposed to 1 verify valve operability by full-stroke exercising these valves on a -I refueling outage frequency. I 4.3.2.1.1 Licensee's Basis for Reouestino Relief- "The only practical method of exercising these valves is to inject water into the Reactor Coolant System via the Makeup and/or HP Injection Pumps. [Forall valves, except SIM-036, this would require initiatim; of HP Injection and pumping water from either the BWST or the CVAT. This would cause transients in pressurizer level and reactor power and is considered to be imprudent during power operation. In addition, injection of cold water into the .
Reactor Coolant System during operation would cause thermal shocking cf the
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injection nozzles. Valve SIM 036 is partial-stroke exercised to the open direction during normal operation of the Makeup System; however system flowrate is generally less than the 500 gpm required for stroking the valve to its fully opened position based on design flow conditions."
]
"During cold shutdown, the HP Injection Isolation motor-operated valves and pumps are closed and electrically disabled to prevent low-temperature over pressurization. Cold shutdown testing is thereby precluded."
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" Valve SIM-036 will be partial-stroked to the open position in conjunction with the normal operation of the Makeup System and verified to close at cold shutdown by handwheel operation. Each of these valves will be j full-stroke exercised during each refueling outage." !
! 4.3.2.1.2 Evaluation--Valve SIM 036 cannot be full-stroke exercised during power operation as the makeup pump cannot develop sufficient exercising flow. Valves SIM-040, HV-23801, and SIM-047 cannot be full-stroke exercised during power operation because the resultant injection of higher concentration boric acid could cause a reactor shutdown. Valves SIM-040, HV-23801, and SIM-047 canno'. oe full-stroke exercised during ccid shutdown since this could result in low temperature overpressurization of the RCS. Valve SIM-036 will be closure verified during cold shutdowns (see
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section 2.3 of Appendix A of this report). Compliance with the Code required testing frequency would be burdensome since this would require quarterly plant shutdown, cooldown, and reactor head removal.
Based en the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested.
4.4 Decay Heat Removal System 4.4.1 Cateoory A Valves 4.4.1.1 Relief Reouest. The licensee has requested relief from j conducting seat leakage tests for core flood tanks sample and drain isolation valves HV-26515 and HV-26516 according to Section XI, Paragraph
,' IWV-3423 and has proposed to leak test these valves with test pressure applied downstream of the valves.
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4.4.1.1.1 Licensee's Basis for Reouestino Relief- " Testing these j valves in the " accident direction" would require draining the core flood tanks, resulting in a large quantity of liquid radwaste (7500 gallons / tank) i requiring processing and disposal. This is considered impractical from the j view point of placing undue demands on the existing radioactive waste ]
processing facility and increases in personnel radiation exposure." l 35
"These valves are one-inch solid wedge gate valves. It is reasonable ,
to assume that, for this size and type of valve, the seating performance at, a test pressure of 52 psig is equivalent in either direction. In the past, ,
with a' nominal pressure differential of approximately 600 psig present during normal plant operation, these valves have proven to be highly reliable with respect to their leaktight integrity."
"Each of these valves may be leaktested in a direction opposite to that expected when the valve is performing its containment isolation function.
At least once per operating cycle each valve will be checked for excessive leakage while the core flood tanks are pressurized to normal. operating pressure."
l 4.4.1.1.2 Evaluation--Valves HV-26515 and HV-26516 cannot be leak l tested as required by the Code due to system design, which would require draining the core flood tanks and processing and disposing of approximately 15,000 gallons of borated liquid radiological waste. Application of test pressure to the downstream side of these solid wedge gate valves is a reasonable alternative to the Code requirements. Compliance with the Code l required testing method would be burdensome since this would requ. ire core flood tanks draining and liquid processing.
Based on the impracticality of complying with the Code required testing
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method and the licensee's proposed alternative testing, relief from the Code requirements may be granted as requested.
4.4.2 Cateaory C Valves 4.4.2.1 Relief Reauest. The licensee has requested relief from l
, exercising spray additive tanks to decay heat removal pumps suction check valves CBS-035 and CBS-036 according to Section XI, Paragraph IWV-3522 and has proposed to verify valve operability by check valve sample disassembly / inspection on a refueling outage frequency.
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4.4.2.1.1 Licensee's Basis for Reauestina Relief- "These are spiing-loadedcheckvalvesandthus,theonlymethodoftestingrequires injection of sodium hydroxide into the Decay Heat Removal System. This is highly undesirable under any plant condition. Contamination of the Decay Heat Removal System with NaOH solution could ultimately result in Na0H in the Reactor Coolant System with the possibility of causing stress cracking, increased radiation levels due to sodium activation and chloride contamination as a result of residual chlorides in the NaOH solution."
"On an alternating schedule, one of these valves will be disassembled and inspected to ensure operability during each refueling outage. If this inspection results in questionable operability of the inspected valve, then the remaining valve will be similarly disassembled and inspected." -
4.4.2.1.2 Evaluation--Valves CBS-035 and CBS-036 cannot be full-stroke exercised.open with flow at any time since this would result in contamination of the decay heat removal system with sodium hydroxide. When the decay' heat removal system is subsequently utilized for cold shutdown decay heat removal, the RCS would also become contaminated, which Twould result in RCS increased radiation due to sodium activation, increased RCS caustic stress corrosion, and RCS chloride contamination from sodium hydroxide residual chlorides.
Check valve sample disassembly / inspection using a manual full-stroke of the disk is an acceptable alternative method to verify the full-stroke capability of check valves. The sampling technique requires that each valve in the 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 the licensee must verify 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 1
37
, l group must also be disassembled, inspected, and manually full-stroked at the same outage. .
Compliance with the Code required testing frequency would be burdensome since this would require quarterly shutdown and valve disassembly. Based on the impracticality of complying with the Code required testing frequency and the licensee's proposed alternative check valve sample disassembly / inspection, relief from the Code requirements may be granted as requested, provided that the licensee tests these check valves in accordance with the provisions described above.
4.4.2.2. Relief Reauest. The licensee has requested relief from exercising boric acid pumps discharge to decay heat removal pumps suction check valve BWS-045 according to Section XI, Paragraph IWV-3521 and has proposed to verify valve operability by full-stroke exercising this valve on a refueling outage frequency.
4.4.2.2.1 Licensee's Basis for Recuestino Relief- "In order to exercise this valve flow must be induced from the Boric Acid Pumps.through the Decay Heat Rr.moval System thence to the BWST. This would necessarily introduce a large quantity of highly concentrated boric acid solution (7750 ppm) into the Decay Heat System drop leg. This concentrated boric acid will remain in the drop leg until the Decay Heat Removal system is placed in service. After successive tests in this manner, a pocket of highly concentrated boric acid could accumulate.with the potential of I crystallization since the decay heat removal piping is not heated.
Subsequently this could adversely affect the operability of the decay heat removal system."
"During cold shutdown, injecting the concentrated boric acid solution !
1
)
would likewise cause an unwanted increase of the boric acid concentration in the Reactor Coolant System that would result in additional radwaste loads and would cause delays due to excessive deborating prior to plant startup."
~
38 1
- - _ _ - _ _ _ _ _ - - - _ _ _ _ _ _ _ _ _ - _ _ _ - _ _ - - - _ _ _ _ _ _ - _ - - _ _ - _ _ . _ - _ _ . _ _ - _a
"This valve will be full-stroke exercised during each refueling I outage."
4.4.2.2.2 Evaluation--Valve BWS-045 cannot be full-stroke exercised during power operation as the resultant accumulation of highly concentrated boric. acid in the unheated decay heat removal system suction drop leg could result in subsequent crystallization and pipe blockage. This valve cannot be full-stroke exercised during cold shutdown as the resultant injection of higher concentration boric acid would result in delay of plant startup due to the time required to decrease the plant higher boric acid concentration to startup concentration. Compliance with the Code required testing frequency would be burdensome since this would require quarterly !
plant shutdown and time consuming boric acid changes.
Based on the impracticality of complying with the Code required testing frequency, and the licensee's proposed alternative testing frequency, relief from the Code requirements may be granted as requested.
4.4.3 Cateaory A/C Valves .
4.4.3.1 Relief Reauest. The licensee has requested relief from exercising core flood tanks ditharge check valves CFS-001 and CFS-002 according to Section XI, Paragraph IWV-3522. The licensee has proposed to verify valve operability by partial-stroke exercising these valves during cold shutdown, leak testing these valves during cold shutdown if not performed in the previous nine months, and disassembly / inspection of one of these valves during Refueling Outage No. 7 with disassembly / inspection of the other valve if the first disassembled valve's full-stroke capability is in question.
4.4.3.1.1 Licensee's Basis for Reauestino Relief- " Exercising these valves during plant operation is not possible since the maximum Core Flood Tank pressure is considerably less than that of the Reactor Coolant System."
I 39 .
I
_ - - - -- )
F " Full-stroke testing during cold shutdown or refueling would require a .
rapid depressurization of the Reactor Coolant System or, conversely, rapid -
pressurization of the Core Flood Tanks; neither is practical." .
i "These valves are seldom operated, therefore, valve degradation as a result of wear or abuse is not likely."
"A partial-stroke test followed by a leakrate test adequately ensures that a valve of this type is intact and functioning properly.. Any significant deterioration of the valve internals or operating mechanism will likely be discovered during such a leak test." '
"During cold shutdown, if not tested in the previous 3 months, each-l valve will be partial-stroke tested prior to returning to power operation.
Additionally during cold shutdown, each valve will be leak tested if not tested in the previous 9 months. Prior to plant startup at the next Refueling Outage No. 7, (Loading Core Cycle 8) one of these valves will be disassembled, manually exercised, and inspected internally. If, as a result of inspection, it is determined that its full-stroke capability is.in question,-the other valve will be disassembled, manually exercised and l inspected."
4.4.3.1.2 Evaluation--Valves CFS-001 and CFS-002 cannot be full-stroke exercised during power operation since core flood tank pressure cannot overcome RCS pressure. These valves cannot be exercised during cold shutdown due to lack of RCS volume to contain the necessary exercising flow. Check valve sample disassembly / inspection using a manual full-stroke >
of the disk is an acceptable alternative method to verify the full-stroke capability of check valves, however, the licensee's proposal to perform this i .' once during the next refueling outage is not acceptable.
Based on the determination that meeting the Code requirements is not impractical because a suitable method is available to full-stroke exercise these valves, relief may be granted, provided that the licensee implements sample disassembly / inspection as discussed in Section 4.4.2.1.2. .
l l
40 1
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4.4.3.2 Relief Recuest. The licensee has requested relief from leak ra'te evaluation of core flood tanks discharge check valves CFS-001 and CFS-002, decay heat removal to RCS check valves DHS 015 and DHS-016, and core flood tanks discharge and decay heat removal to RCS check valves
. RCS-001 and RCS-002 according to Section XI, Paragraph IWV-3427(b) and has proposed to evaluate leakage for these valves according to Rancho Seco Technical Specifications Table 3.3-1.
4.4.3.2.1 Licensee's Basis for Recuestino Relief- " Leak testing of these valves is for the purpose of confirming their pressure retaining integrity with respect to their capability of preventing overpressurization and catastrophic failure of the low pressure decay heat removal piping and components. In this regard, special leakage acceptance criteria is established and included into the Rancho Seco Technical Specifications (Reference Table 3.3-1) that addresses the question of valve integrity in a more appropriate manner for these valves."
"The' leakage rate acceptance criteria for these valves will' be as set forth in the Rancho Seco Technical Specifications, Table 3.3-1, namely:
- 1. Leakage rates less than or equal to 1.0 gpm are considered acceptable.
- 2. Leakage rates greater than 1.0 gpm but less than or equal to 5.0 gpm are considered acceptabis,if the latest measured rate has not exceeded the rate determined by the previous test by an amount that reduces the margin between measured leakage rate and the maximum permissible rate of 5.0 gpm by 50% or greater.
- 3. Leakage rates greater than 1.0 gpm but less than or equal to 5.0 gpm are considered ur. acceptable if the latest measured rate exceeded the rate determined by the previous test by an amount that redeces the margin between measured leakage rate and the maximum permissible rate of 5.0 gpm by 50% or greater.
- 4. Leakage rates greater than 5.0 gpm are considered unacceptable."
41
7 4.4.3.2.2 Fvaluation--The leakage rate acceptance criteria for ~
valves CFS-001, CFS-002, DHS-015 DHS-016, RCS-001, and RCS-002 as defined '
in Rancho Seco Technical Specifications Table 3.3-1-essentially meets the
- Code requirements of-IWV-3427(b) and reasonably determines the leak tight integrity of these valves.
Based on the equivalency of the Code. requirements and the Technical Specification acceptance criteria for these valves, relief from the Code requirements may be granted as requested.
4.5 Reactor Buildino Sorav System 4.5.1 Cateoory C Valves 4.5.1.1 Relief Recuest. The licensee has requested relief from exercising spray additive tanks to reactor building spray pumps suction check valves CBS 021, CBS-022 CBS-027, and CBS-028 and spray additive tanks to reactor building spray pumps suction stop check valves SFV-29015 and SFV-29016 according to Section XI, Paragraph IWV-3522 and has proposed to verify valve operability by check valve sample disassembly / inspection on a refueling outage frequency.
4.5.1.1.1 Licensee's Basis for Recuestino Relief- " Full flow testing of these valves would require injection of sodium hydroxide into the Reactor Building spray system and the borated Water storage tanks. This is undesirable since this could ultimately result in NaOH in the Reactor Coolant System with the potential for causing stress cracking, increased radiation levels due to sodium activation and chloride contamination due to
, residual chlorides in the Na0H solution."
" Partial flow testing of these valves during plant operation requires isolation and disabling of one train of the Reactor Building Spray System along with the elimination of the redundancy of Reactor Building Spray Additive Tanks. This is undesirable from the aspect of plant safety."
"During cold shutdown periods, each of these valves will be partial-stroke tested."
42
.g ..
I "The' motor operators and stem assemblies of SFV-29015 and SFV-29016 )
will be exercised quarterly."
"During each Reactor refueling outage, on an alternating schedule one of each type of valve will be disassembled and manually exercised to ensure operability. If it is found that the inspected valve's operability is in question, then the remainder of the valves of that type will be disassembled, exercised and inspected in a similar manner."
4.5.1.1.2 Evaluation--Valves CBS-021, CBS-022, CBS 027, CBS-028, SFV-29015, and SFV-29016 cannot be partial- or full-stroke exercised oper.
with flow at any time since this would result in contamination of the
^
reactor building spray system and BWST with sodium hydroxide. When the BWST is subsequently utilized as an RCS borated water source for cold shutdown, sodium hydroxide contamination would result after plant startup in RCS increased radiation due to sodium activation, increased RCS caustic stress corrosion, and RCS chloride contamination from sodium hydroxide residual chlorides. .
Check valve sample disassembly / inspection using a manual full-stroke of the disk is an acceptable alternative method to verify the full-stroke capability of check valves. The licensee should perform check valve sample disassembly / inspection of these valves as described in section 4.4.2.1.2 of, this report. Compliance with the Code required testing frequency would be burdensome since this would require quarterly or cold shutdown valve disassembly.
Based on the impracticality of complying with the Code required testing
.' frequency and the licensee's proposed alternative check valve sample disassembly / inspection, relief from the Code requirements may be granted, provided that the licensee tests these check valves in accordance with the provisions described in section 4.4.2.1.2 of this report.
4.5.1.2 Relief Recuest. The licensee has requested relief from exercising inside reactor building spray header check valves CBS-009 and CBS 010 according to Section XI, Paragraph IWV-3522 and has proposed to l
l I 43 L___-_____-_----------------------.----_-------------- - _ - - - - - - - - _ - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
l verify valve operability by check valve sample disassembly / inspection on a -
refueling outage frequency, ,
4.5.1.2.1 Licensee's Basis for ~Recuestino Relief- "The only method of exercising these valves.is to operate the Reactor Building spray pumps and inject water through the valves to the spray headers. Since there is no practical means of isolating the spray headers and providing a recirculation, this would result in spraying down the Reactor Building, which is highly undesirable." .
"During each refueling outage, on an alternating schedule, one of these valves will be disassembled and manually exercised to ensure operability.
If this inspection results in questionable operability of the inspected valve, then the remaining valve will be disassembled, exercised and :
inspected in a similar manner."
4.5.1.2.2 Evaluation--Valves CBS-009 and CBS-010 cannot be exercised open with flow at any time since this would result in spraying containment and could cause electrical equipment damage and wet lagging.
Check valve sample disassembly / inspection using a manual full-stroke of the disk is an acceptable alternative method to verify the full-stroke capability of check valves. The licensee should perform check valve sample disassembly / inspection of these valves as described in section 4.4.2.1.2 of this report. Compliance with the Code required testing frequency would be burdensome since this would require quarterly shutdown and valve disassembly.
Based on the impracticality of complying with the Code required testing l frequency and the licensee's proposed alternative check valve sample
.' disassembly / inspection, relief from the Code requirements may be granted as reouested, provided that the licensee tests these check valves in accordance with the provisions described in section 4.4.2.1.2 of this report.
44
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ - _ _ l!
o
. . 4 4.6 Hich Pressure Feedwater Heater System 4.6.1 Cateaory C Valves
. 4.6.1.1 Relief Reauest. The licensee has requested relief from exercising auxiliary feedwater pumps minimum flow check valves FWS-049 and
{
FWS-050 according to Section XI, Paragraph IWV-3521 and has proposed to l verify valve operability by full-stroke exercising these valves on a refueling outage frequency.
4.6.1.1.1 Licensee's Basis for Reauestina Relief- "There is no way these valves can be verified to be in the full open position without isolating the recirculation line for both auxiliary feedwater pumps from the
~
LP condenser which would result both auxiliary feedwater pumps to be considered inoperable. Thus, testing during plant operation is not practical from the viewpoint of reactor safety."
"Perf'orming the tests, including verification of full flow, requires special (unusual) valve lineups and the installation of special telt equipment. Such testing is considered r"t of the normal workscope expected during a typical cold shutdown (non-refueling) outage."
"These valves will be exercised on a quarterly basis without -
verification of full flow. Verification of full-flow through the valves will be performed during each refueling outage."
4.6.1.1.2 Evaluation--Valves FWS-049 and FWS-050 cannot be verified to full-stroke exercise during power operation as verification .
requires that both auxiliary feedwater pumps be made inoperable to install l
test equipment and conduct the testing. These valves will be partial-stroke exercised quarterly. These valves cannot be verified to full-stroke exercise during cold shutdown as procedures required for installation of test equipment and testing could delay plant startup. Compliance with the Code required testing frequency would be burdensome since this would require quarterly shutdown and test equipment installation.
~
45
'. l Based on the impracticality of complying with the Code required testing -
frequency and the licensee's proposed alternative testing, relief from thd Code requirements may be granted as requested. -
i 4.7 Coolant Radwaste System 4.7.1 Cateaory A Valves 4.7.1.1 Relief Reauest. The licensee has requested relief from conducting seat leakage tests for reactor coolant vent header isolation valve SFV-60001 and reactor coolant drain header isolation valve SFV-60003 according to Section XI, Paragraph IWV-3423 and has proposed to leak test these valves with test pressure applied downstream of the valves.
4.7.1.1.1 Licensee's Basis for Reauestina Relief- "In these cases it is impractical to test gate valves in their functional direction. Where valves are provided with a bonnet tap or other means of venting between the seats, it is conservative to pressurize in the reverse direction with the valve internal space between the seats vented. This provides an acceptable
~
means of determining the material condition of the downstream seating >
surface that must perform the leaktight service."
" Category A gate valves may be seat leak tested in a direction opposite !
to that when the valve is performing its function. When testing is ,
l performed in this manner, a valve body vent will be open to atmosphere to vent the cavity between the seats. The seating surface is subjected to the full differential pressure in the reverse direction. This is conservative I
since the effect of the imposed pressure tends to unseat the valve."
4.7.1.1.2 Evaluation--Leak testing valves SFV-60001 and SFV-60003 with test pressure applied downstream is a reasonable alternative to the Code requirement that these valves have test pressure applied upstream.
With test pressure applied opposite to the functional direction of flow, measuring leakage from the valve's body cavity is more conservative than the Code requirement in that the test pressure is tending to unseat the disk during the test.
1 46
Based on the licensee's proposed alternative equivalent or better
. testing, relief from the Code requirements may be granted as requested.
4.8 Emeroency Diesel Generator System 4.8.1 Cateaory B Valves 4.8.1.1 Relief Reauest. The licensee has requested relief from measuring the stroke time of the following diesel generators air start isolation valves according to ("c' t9n XI, Paragraph IWV-3413 and has proposed to verify valve operability by monitoring proper diesel startup and operation.
FY-89025 FY-89026 FY-89027 FY-89028 FV-89029 FV-89030 FV-89031 FV-89032 HV-10050A HV-10050B HV-10051A HV-10051B 4.8.1.1.1 Licensee's Basis for Recuestina Relief- "Since these valves have no position indication mechanism, stroke timing is not practical."
4.8.1.1.2 Evaluation--These valves cannot be stroke timed due to the lack of position indication. Unsatisfactory stroke time of these valves will be indicated by the diesel generator failing to reach rated speed in the required time after diesel start. Conformance with the Code required testing method is impractical due to system design.
I Based on the impracticality of complying with the Code required testing method and the licensee's proposed alternative testing method, relief from
. the Code requirements may be granted as requested.
4.8.2 Cateaory C Valves 4.8.2.1 Relief Reauest. The licensee has requested relief from exercising TDI diesel generator air receivers inlet check valves EGS-564, l EGS-565, EGS-566, and EGS 567 according to Section XI, Paragraph IWV-3522 and has proposed to verify valve operability by check valve sample disassembly / inspection on a refueling outage frequency. j 47
- ,1 4.8.2.1.1 Licensee's Basis for Recuestino Relief- "Due to the .
piping configuration of this system the only method of testing would re, quire.
depressurization of the upstream piping. This would be an unacceptable .
method since it would require removing a portion of the air start system and compromising the start capabilities of the Emergency Diesel Generator -
System."
"One of these valves will be disassembled and inspected to ensure operability during each refueling outage. If this inspection results in questionable operability of the inspected valve, then the remaining valves will be similarly disassembled and inspected."
4.8.2.1.2 Evaluation--Valves EGS-564, EGS-565, EGS-566, and EGS-567 cannot be full-stroke exercised during power operation as this would require removing a portion of the TDI diesel generator air start system thus the 101 diesel generators would be inoperable. Check valve sample disassembly / inspection using a manual full-stroke of the disk is an acceptable alternative method to verify the full-stroke capability of check valves. The licensee should perform check valve sample disassembly / inspection of these valves as described in section 4.4[2.1.2 of this report. Compliance with the Code required testing frequency would be i burdensome since this would require quarterly shutdown and valve disassembly.
Based on the impracticality of complying with the Code required testing frequency and the licensee's proposed alternative check valve sample disassembly / inspection, relief from the Code requirements may be granted as requested, provided that the licensee tests these check valves in accordance with the provisions described in section 4.4.2.1.2 of this report.
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9 9
APPENDIX A
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VALVES TESTED DURING COLD SHUTDOWNS 0
4 4
49
APPENDIX A VALVES TESTED DURING COLD SHUTDOWNS The following are Category A, B, C, and A/C valves that meet the
. exercising requirements of the ASME Code,Section XI, and are not full-stroke exercised every three months during plant operation. These valves are specifically identified by the owner in accordance with Paragraphs IWV-3412 and 3522 and are full-stroke exercised during cold shutdowns and refueling outages. All valves in this Appendix have been evaluated and the reviewer agrees with the licensee that testing these valves during power operation is not possible due to the valve type and location or system design. These valves should'not be full-stroke exercised ,
durir.g power operation. These valves are listed below and grouped according to the system in which they are located.
- 1. REACTOR COOLANT SYSTEM 1.1 Cateoory B Valves -
Steam generator vent valves HV-20533, HV-20534, HV-20579, and HV-20580 and pressurizer vent valves HV-21522 and HV-21528 cannot be exercised during power operation as they are required to be de-energized closed by technical specifications. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
- 2. MAKEUP AND PURIFICATION SYSTEM
..' 2.1 Cateaory A Valves Letdown containment isolation valves SFV-22009 and SFV-22023 and makeup line isolation valve SFV-23604 cannot be exercised during power operation as closure failure would ir,terrupt pressurizer level control and could result in a reactor shutdown. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
51
1
. -l RCP seal water isolation valves SFV-24004, SFV-24013, and SFV-23616 cannot be exercised during power operation as cessation of RCP seal wat'er could result in RCP seal failure. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
2.2 Cateaory B Valves Letdown isolation valves SFV-22005 and SFV-22025 and makeup tank isolation valve SFV-23508 cannot be exercised during power operation as closure failure would interrupt pressurizer level control and could result in a reactor shutdown. These valves will be full-stroke exercised during cnid shutdowns and refueling outages. '
2.3 Cateoorv C Valves -
Discharge to reactor inlet loop A check valve SIM-036 cannot be closure '
verified during power operation as containment is inaccessible and the valve is verified to close with its handwheel. This valve will be closure verified during cold shutdowns and refueling outages. [
2.4 Cateoorv A/C Valves RCP seal supply check valves SIM-019, SIM-020, SIM-021, and SIM-022 cannot be exercised during power operation as cessation of RCP seal water could result in RCP seal frilure. These valves'will be full-stroke exercised during cold shutdowns and refueling outages.
- 3. DECAY HEAT REMOVAL SYSTEM 3.1 Cateoory A Valves i
Reactor building sump isolation valves HV-26105 and HV-26106 cannot be exercised during power operation as the required valve lineup to preclude sump flooding renders one train of decay heat removal, safety injection, and containment spray systems inoperable. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
1 52 i V
l*
. 3.2 Cateaorv B Valves Decay heat removal dump to sump isolation valve HV-20003 cannot be exercised during power operation as the required valve lineup to preclude draining decay heat removal piping requires containment entry. This valve will be full-stroke exercised during cold shutdowns and refueling outages.
Decay heat removal supply isolation valves HV-20001 and HV-20002 cannot be exercised during power operation because they are interlock closed when RCS pressure is greater than 255 psig. These valves will be full-stroke exercised dur'ing cold shutdowns and refueling outages.
3.3 Cateaory C Valves '
Decay heat removal to pressurizer spray check valve DHS-059 cannot be exercised during power. operation as the resultant spray nozzle thermal shock could causp premature nozzle failure. This valve will be full-stroke exercised during cold shutdowns and refueling outages. .
3.4 Cateaory A/C Valves Decay heat leakage check valves DHS-017 and DHS-018 cannot be exercised during power operation as closure verification requires access to containment. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
Decay heat removal to RCS check valves DHS-015 and DHS-016 and decay heat removal / core flood to ECS check valves RCS-001 and RCS-002 cannot be
. exercised during power operation as neither are the decay heat removal pumps nor the core flood tanks capable of overcoming RCS pressure. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
53
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, f, ;.
- 4. HP AND AUXILfARY TURBINES SYSTEM 4.1 Cateaory B Valves '
1 -
Main turbine throttle valves TV-1, TV-2, TV-3, and TV-4 cannot be exercised during power operation as this would require a main turbine trip.
These valves will be full-stroke exercised during cold shutdowns and refueling outages.
Main steam supply to reheaters isolation valves HV-20597 and HV-20598 cannot be exercised during power operation as this could result in reheater damage due to pressure and thermal transients. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
Main turbine bypass valves PV-20561, PV-20563, PV-20564, and PV-20566 and atmospheric steam dump valves PV-20562A, PV-20562B, PV-20562C, PV-20571A, PV-20571B, and PV-20571C cannot be exercised during power operation because these valves require isolation to be exercised which would diminish the plant's ability to respond to turbine or reactor trips. These valves will be full ' stroke exercised during cold shutdowns and ref,[ueling outages.
Main turbire bypass isolation valves HV-20521 and HV-20522 cannot be exercised during power operation as this could result in downstream piping damage due to pres:ure end thermal transients. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
4.2 Cateaory C Valves Main steam to auxiliary feedwater pump check valves MSS-051 and MSS-052 cannot be exercised during power operation as closure verification requires depressurization of the related steam generator. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
54
. A .*
- . 5. , STEAM GENERATOR SYSTEM 5.1 Cateaory B Valves Main feedwater isolation valves FV-20525 and FV-20526, main feedwater bypass valves FV-20575 and FV-20576, and main feedwater stop valves
~
HV-20529, HV-20530 HV-20515, and HV-20516 cannot be exercised during power l
operation due to the resultant loss of steam generator water level control l
and subsequent reactor trip. These valves will be full-stroke exercised during cold thutdowns and refueling outages.
5.2 Cateaory C Valsy Emergency feedwater check valves FWS-061 and FWS-062 cannot be exercised during power operation as injection of cold water would result in auxiliary feedwater nozzle thermal shock and possible premature failure.
These valves will be full stroke exercised during cold shutdowns and refueling outages. .
- 6. COMPONENT COOLING WATER SYSTEM ;
6.1 Catecory A Valves 4
Component cooling water i, solation valves SFV-46014, SFV-46203, SFV-46204, SFV-46906, SFV-46907, and SFV-46908 cannot be exercised during power operation as cooling water isolation could result in damage to the RCPs and/or control rod drive mechanisms. These valves will be full-stroke exercised during cold shutdowns and refueling outages.
6.2 Cateaory A/C Valves i
Component cooling water check valves CCW-036 and CCW-194 cannot be j
. exercised during power operation as cooling water isolation could result in i damage to the RCPs and/or control rod drive mechanisms. These valves will )
be full-stroke exercised during cold shutdowns and refueling outages.
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1
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, t. :
- 7. REACTOR BUILDING HEATING, VENTILATING, AND AIR CONDITIONING SYSTEtt -
7.1 Cateoory A Valves Reactor building purge isolation valves SFV-53503, SFV-53504, SFV-53603, and SFV-53604 cannot be exercised during power operation because they are required to be de-energized closed per technical specifications.
These valves will be full-stroke exercised during cold shutdowns and refueling outages.
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APPENDIX B
'P&ID LIST O
M e
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' T i? l,';
...:,c..
. APPENDIX B 1 P&lD LIST
- The P&lDs listed below were used during the course of this review.
System P&lD Revision Reactor Coolant System M-520-1 34 M-520-2 14 Makeup and Purification M-521-1 14 System _ M-521-2 15 M-521-3 9 Decay Heat Removal System M-522-1 33 -
Reactor Building Spray M-524 10 System High Pressure and Auxil- M-530-1 13 iary Turbines System M-530-2 12 M-530-2A 3 M-530-3. 17 :
Steam Generator System M-532-1 9 M-532-2 6
. M-532-3 6 High Pressure Feedwater M-533-3 10 Heater System Condenser System M-536 26 Auxiliary Steam System M-537-3 12 Component Cooling Water M-543-1 6 System M-543-4 13 Nuclear Service Raw M-544 20 Water System Nuclear Service M-545 15 Cooling Water System Reactor Building HVAC M-551 27 System Coolant Radwaste System M-560-3
- 8 j 59
, L
. , a
' ~
System P&lD Revision '
k
- Miscellaneous Liquid M-561-3 4 L Radwaste System Reactor' Coolant Chemical M-570 25 Addition and Sampling '
System Turbine Plant Sampling M-573 17 Plant-Air System M-590-1 37
- l. Auxiliary Gas System M-591-1 37 Miscellaneous Water M 593-2 12
- Systems Emergency Diesel Generator M-583-1 14 System Diesel Oil System M-582-1 25 6
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APPENDIX C IST PROGRAM AN0MAllES IDENTIFIED DURING THE REVIEW w
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. ,, APPENDlX C IST PROGRAM ANOMALIES IDENTIFIED DURING THE REVIEW Inconsistencies and omissions in the licensee's program noted during the course of this review are summarized below. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.
- 1. Pump relief request PR-13 requests relief from the IWP-3500(a) requirement that the diesel fuel oil transfer pumps be operated five minutes prior to taking test data. In his basis for relief the licensee states that the only method for determining flow rate for these pumps is by day tank level change over time, but the licensee has not specifically requested relief from the IWP-4600 requirement that flow rate be determined utilizing a rate or quantity meter installed in the pump test circuit. Granting relief for this requirement is not a problem (see Sectian 3.2.7 of this report), however, the licensee should modify pump relief request PR-13 to also request relief from the IWP-4600 requirements for these pumps.
- 2. Pump relief request PR-2 requests relief from pump vibration displacement measurements and proposes to utilize pump vibration velocity measurements. However, the licensee has not provided enough technical information for his alternative testing to determine if relief should be granted (see section 3.3.1 of this report). The vibration velocity testing guidance of ASME document OM-6, draft 10, is an acceptable alternative to the vibration monitoring required by Section XI, provided that all of the OM 6 guidance for vibration velocity monitoring is utilized and contained in the relief request. Relief may be granted, provided that the licensee utilizes all of the OM-6 guidance for vibration velocity monitoring of pumps in the IST program.
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- 3. Pump relief request PR-4 requests relief from the Table IWP-310,0-2 ~. j Alert-range (high) and Required-action range (high) differential -
pressure and flow rate limits and proposes to raise these limits (see section 3.2.2 of this report). This is not a reasonable !
alternative to the Code limits, according to the NRC staff, thus relief should be denied.
- 4. Valve relief request VR-1 requests relief from the IWV-3a17 corrective action requirement for rapid acting power operated valves that stroke in two seconds or less (see Section 4.1.2.1 of this report). Relief may be granted provided that the licensee implements the relief in accordance with the guidelines provided in Section 4.1.2.1.2 of this report. .
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- 5. Valve relief request VR-2 requests relief from the IWV-3417 corrective action requirement of measuring degraded and increasing valve stroke times monthly for valves identified as being tested on a cold shutdown frequency (Appendix A of this report). The licensee wishes to test cold shutdown frequency tested degraded valves that are not being repaired, during cold shutdown rather than monthly as the monthly testing would not be applicable.
Relief should not be granted as corrective action requires that the degraded valves be repaired, and not just left in the degraded conditicn while being tested on a cold shutdown frequency (see sectior 4.1.3.1 of this report).
- 6. Valve relief request VR-4 requests relief to substitute 10 CFR 50, Appendix J 1eak testing requirements for IWV-3421 through IWV-3425 leak testing requirements for containment isolation valves. The licensee has not specifically identified the IWV-3421 through IWV-3425 leak testing requirements as those for which he is r.equesting relief (see Section 4.1.4.1 of this report). The licensee should modify relief request VR-4 to identify the IWV-3421 through IWV-3425 leak testing requirements as those for which he is requesting relief.
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- 7. The alternate testing of valve relief request VR-8 identifies
. ~. . valve SIM-037 as being verified to close during cold shutdowh with its handwheel. P&lD M-521, sheet 2 indicates that this valve is
-I not a stop check,_ but a simple check. The licensee's valve
- listing (page B-10) also indicates that this valve is not a stop check valve. The licensee should correct this inconsistency.
Further ,the valve listing (page B-10) indicates that stop check valve SIM-036 will be partial-stroke exercised closed at cold shutdown with its handwheel. Positioning the handwheel of a stop check valve to the closed position verifies full and not partial closure.
- 8. Valve relief requests VR-ll, VR-13, VR-14 VR-15, and VR-23 propose to utilize check valve sample disassembly / inspection to verify the full-stroke capability of the' concerned check valves.
Granting relief for these requests is acceptable, provided that the licensee tests these check valves in accordance with the provisions described in section 4.4.2.1.2 of this report.- ,
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., .....,.we............o EGG-NTA-8402 TECHNICAL EVALUATION REPORT, PUMP AND VALVE INSERVICE TESTING PROGRAM, RANCHO SECO NUCLEAR GENERATING STATION ' '"*c'*"**8-"
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R. Bonney, T. L. Cook, and H. C. Rockhold I
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February 1989
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Regulatory & Technical Assistance ....,c....,w..
EG8G Idaho, Inc.
P. O. Box 1625 A6812 Idaho Falls, ID, 83415
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Mechanical Engineering Brancn Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission .m..co co...u .
Washington, DC, 20555
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inis EG8G Idaho, Inc. report presents the results of our evalua~~tion of the Rancho Seco Nuclear Generating Station, Inservice Testir.g Program for pumps and valves that perform a safety-related function.
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