ML20058K531

Technical Evaluation Rept Re Pump & Valve Inservice Testing Program Dresden Nuclear Power Station,Units 2 & 3

ML20058K531
Person / Time
Site:	Dresden
Issue date:	06/30/1990
From:	Hartley R EG&G IDAHO, INC.
To:	NRC
Shared Package
ML17202U773	List: ML20058K531
References
CON-FIN-A-6812 EGG-NTA-9104, TAC-49083, TAC-49096, NUDOCS 9007090111
Download: ML20058K531 (83)

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'l EGG-NTA-9104 TECHNICAL EVALUATION REPORT-PUMP AND VALVE INSERVICE TESTING PROGRAM DRESDEN NUCLEAR POWER STATION, UNITS 2 AND 3 Docket No. 50-237 and 50-249 R. S. Hartley Published June 1990 Idaho National Engineering Laboratory EG&G Idaho, Inc.

Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Under DOE Contract No. DE-AC07-761001570 FIN No. A6812 TAC Nos. 49083 and 49096 9 0 e1

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. ABSTRACT This EG&G Idaho, Inc., report presents the results of our evaluation of the Dresden Nuclear Power Station, Units it and 3, Inservice Testing Program for safety-related pumps and valves.

PREFACE This report is supplied as part of the " Review of Pump and Valve Inservice Testing Programs for Operating Reactors (III)" being conducted for the U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor  !

Regulation, Hechanical Engineering Branch, by EG&G Idaho, Inc., Regulatory and Technical Assistance Unit.

1 FIN No. A6B12 B&R 920-19-05-02-0 Docket Nos. 50-237 and 50-249 TAC Nos. 49083 and 49096 11

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CONTENTS i

1 ABSTRACT ................................................,,,,,,,,,,,,,, jj I PREFACE ............................................................... 11 l

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1. INTRODUCTION ..................................................... I

2. SCOPE ............................................................ 3

3. PUMP TESTING PROGRAM ............................................. 7 3.1 Various Systems ............................................ 7-  !

3.1.1 Relief Request ..................................... 7 3.1.2 Relief Reauest ..................................... 10 3.1.3 Relief Request ..................................... 12  !

3.2 Di e s el Fu el Oil Sys tem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.1 Relief Request ..................................... 13 '

3.3 Die sel Generator Cooling Water System . . . . . . . . . . . . . . . . . . . . . . 14 3.3.1 Relief Request ..................................... 14 3.4 -Standby Liquid Control System .............................. 16 3.4.1 Relief Request .....................................- 16 3.5 High Pressure Cool ant Injection System . . . . . . . . . . . . . . . . . . . . . 18 3.5.1 Relief Request ..................................... 18

4. VALVE TESTING PROGRAM ............................................ 21 4.1 Various Systems ............................................ 21 4.1.1 Power-Opera ted Val ves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -21 4.1.2 Containment Isolation Valves ....................... 26-4.1.3 Exces s Fl ow Check Val ves . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4.2 Control Rod Drive System ................................... 29 4.2.1 C a t eg o ry A Val ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4.2.2 Category B & C Valves .............................. 31 iii

4.3 Main Steam System .......................................... 33-4.3.1 C at eg o ry AC Val ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.3.2 Category BC Valves ................................. 35 4.3.3 C at eg o ry C Val ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.4 High Pressure Coolant Injection System . . . . . . . . . . . . . . . . . . . . . 43 4.4.1 C a t eg ory C V al ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.5 Reactor Head Spray System .................................. 51 4.5.1 C a t ego ry AC Val ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.6 Feedwater System ....................................... ... 52 4.6.1 Category AC Valves ................................. 52 4.6.2 C a t e g o ry C V al v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.7 I sol ati on Condenser Sys tem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 4.7.1 C a t e g o ry C V a l v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 4.8 Standby Liquid Control System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.8.1 Ca teg ory AC Val ve s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.9 Core Spray System .......................................... 58 4.9.1 Category C Valves .................................. 58 4.10 Low Pres sure Cool ant Injection System . . . . . . . . . . . . . . . . . . . . . . 59 4.10.1 Category C Valves .................................. 59 4.11 TIP Nitrogen Purge System .................................. 61 4.11.1 C a t eg ory AC Val v e s . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 APPENDIX A--VALVES TESTED DURING COLD SHUTDOWNS ....................... A-1 APPENDIX B--P&ID LISTING .............................................. B-1 APPENDIX C--IST PROGRAM ANOMALIES IDENTIFIED IN THE REVIEW ............ C-1 l

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TECHNICAL EVALUATION REPORT  !

PUMP-AND VALVE INSFRVICi TESTING PROGRAM l L DRESDEN NUCLFM'/ER STATION. UNITS 2 AND 3

1. INTRODUCTION i

l Contained herein is a technical evaluation of the pump and valve inservice testing (IST) program submitted by the Comonwealth Edison Company for its Dresden Nuclear Power Station, Units 2 and 3.

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By a letter dated May 6,1988, Commonwealth Edison Company submitted  !

Revision 2 of the IST program for Dresden Nuclear Power Station, Units 2  ;

and 3, for their second 10-year inspection interval, which comenced on l March 1, 1982. A working meeting with NRC, EG&G Idaho, Comonwealth Edison Company, and Dresden Station representatives was conducted on May 23 and 24, 1989. The licensee's revised program, Revision 3, dated July 1, 1989, which supersedes all previous submittals, was reviewed to verify compliance of proposed tests of Class 1, 2, and 3 safety-related pumps and valves with the requirements of the ASME Boiler and' Pressure Vessel Code (the Code),Section XI,1977 Edition, through Sumer 1979 Addenda. Any IST program revisions subsequent to those noted above are not addressed in this technical evaluation report (TER). Program changes involving additional or revised relief requests should be submitted to NRC under separate cover in order to receive prompt attention, but should not be implemented prior to review and approval by NRC. Other IST program revisions should follow the guidance in Generic letter No. 89-04, " Guidance on Developing Acceptable Inservice Testing Programs."

In their submittal Commonwealth Edison Company has requested relief from the ASME Code testing requirements for specific pumps and valves and these requests have been evaluated individually against the requirements of 10 CFR 50.55a. This review was performed utilizing the acceptance criteria of the Standard Review Plan, Section 3.9.6, the Draft Regulatory Guide and Value/ Impact Statement titled " Identification of Valves for Inclusion in Inservice Testing Programs," and Generic Letter No. 89-04. The IST Program 1

9 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.

Section 2 of this report presents the scope of the review.  ;

Section 3 of this report presents the Commonwealth Edison Company bases a for requesting relief from the Section XI requirements for the Dresden Nuclear Power Station pump testing program and EG&G's evaluations and conclusions regarding these requests. Similar information is presented in  !

Section 4 for the valve testing program.

This TER, including all relief requests and component identification numbers, is applicable to Units 2 and 3. The Unit 3 designator has been placed in parentheses to minimize repetition, i.e., 2(3)-1402-36A.

4 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&lDs used for this review is contained in Appendix B.

Inconsistencies and omissions in the licensee's program noted during i 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 Dresden Nuclear Power Station inservice '

testing (IST) program for pumps and valves was begun in October 1988. The l initial program examined was Revision 2, dated May 6, 1988, which identified the licensee's proposed testing of safety-related pumps and valves in the L plant systems listed in Appendix B.

l The licensee's proposed IST program was reviewed by locating and highlighting the components on the appropriate system P&lDs and determining 1 their function in the system. Then the licensee's proposed testing was j evaluated to determine if it was in compliance with the ASME Code,Section XI, requirements. During the course of this review, questions and comments were made relative 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, i

Each pump and valve relief request was evaluated individually to determine if the licensee had demonstrated that (1) the Code requirements are impractical for the identified system components, (2) the proposed alternate. testing provides an acceptable level of safety and quality, or (3) compliance would result In hardship or unusual difficulties without a compensating increase in the level of safety. Where the licensee's technical basis or alternate testing was insufficient or unclear, the licensee was requested to clarify the relief request. The system P&ID was also examined to determine whether the instrumentation necessary to make the identified measurements is available. If, based on the unavailability of adequate inttrumentation or the reviewer's experience and system knowledge, it was determined it may not be possible or practical to make 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-31001 were indicated to be measured or observed.

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For those test quantities that were not be hg measured or observed quarterly e' in accordance with the Code, it was verified that a request for relief from I the Code requirements had been submitted. If testing was not being performed in accordance with the Code and a relief request had not been submitted, the licensee was requested to explain the_ inconsistency in the RAI.

The review of the proposed testing of valves verified all appropriate ASME Code testing for each valve is identified to be perfomed as required.

The proposed testing was evaluated to determined if all valves 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 -3520. If any active '

safety-related valve was not full stroke exercised quarterly as required, then the licensee's justification for deviation, either in the form of a i cold shutdown justification or a relief request, was examined to determine its accuracy and adequacy. The proposed alternate testing was also evaluated to determine if all testing is being performed that can reasonably p be performed on each valve to bring its testing as close to compliance with the Code requirements as practical.

For valves with remote position indication, the reviewer confirmed the l

valve remote position indication is identified to be verified in accordance i' with IWV-3300. The reviewer verified 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 the valve's fail-safe actuator was identified to be L tested in accordance with IWV-3415.

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 was employed to determine whether the proposed tests would full-stroke the check valve I disks open or verify their reverse flow closure capability. If there was 1 any doubt about the adequacy of the identified testing, questions were included in the RAI. )

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Further evaluation was performed on ail 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 alert-the licensee to the suspected problem.

Safety-relatsd safety valves and relief valves, e,tcluding those that perform only a thermal relief function, were confirmed to be included in the IST program and tested in accordance with IWV-3510. Safety-related explosively actuated valves were verified to be included in the IST progra and tested in accordance with IWV-3610.

Once all components in the licensee's IST program had been identified ,

on the P& ids and evaluated as described above, the P& ids were examined closely by at least two trained and experienced reviewers to identify

. additional pumps or valves that may perform a safety function which were not included in the licensee's program. The licensee was asked to reconcile any components identified by 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 specific or a general aspect of the licensee's IST program, based on their past experiences, 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 this TER.

At the completion of the review, the RAI was transm tted to the lit.enses. These questions were later used as the agenda for the working meeting with the licensee on May 23 and 24, 1989. At the meeting, each question and comment was discussed in detail and resolved as follows:

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a. The' licensee agreed to make the necessary IST program corrections orl changes to satisfy the concerns of NRC and their reviewers,

b. The licensee provided additional information or clarification about their IST program that satisfied the concerns of NRC and their reviewers, and no program change is required.

c. The item remained open for the licensee to investigate further and ,

propose a solution to NRC.

d. The item remained open for further investigation by the NRC.-

e. The item remained open for further investigation and discussion by both NRC and the licensee. >

The licensee responded to the RAI and working meeting discussions in their program resubmittal, Revision 3, dated July 1, 1989, which was transmitted via J. A. Silady letter to NRC, dated July 12, 1989. The program changes were identified and evaluated to determine whether they were acceptable and,-if not, whether they contributed 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-1 The Dresden Nuclear Power Station inservice testing (IST) program for pumps and valves, submitted by Commonwealth Edison Company, was examined t'o i verify that' all pumps included in the program are subjected to periodic tests required by the ASME Code,Section XI,1977 Edition through Sumner 1979 Addenda, NRC regulations, positions, and guidelines. The reviewers found, that except as noted in Appendix C or where specific relief from testing has been requested, these pumps are tested to the Code requirements, NRC regulations, positions, and guidelines. Each Commonwealth Edison Company basis for requesting relief from pump testing requirements and the reviewer's evaluation of that request are summarized below and grouped according to system.

3.1 Various Systems 3.1.1 Relief Reauest '

The licensee has requested relief from the Section XI,. Paragraph IWP-4500, requirement to measure pump vibration in units of displacement and proposed to monitor pump vibration using a program patterned after ANSI /ASME OH-6, Draft 11, for all pumps in the IST program. Additionally, the licensee has requested relief from the frequency response range requirements L for the standby liquid control (SBLC) pumps, 2(3)A 1102 and 2(3)B-1102, and proposed to utilize available instruments for vibration measurements.

3.1.1.1 Licensee's Basis for Reauestina Relief. The ASME Code requires measurement'of displacement vibration amplitude in mils, thousandths of an inch, every inservice test and bearing temperatures once per year. A far more informative reading is obtained using vibration velocity equipment because it accounts for both displacement and range of frequency.

1 The alternative testing described herein for pump vibration monitoring

-was developed using ANSI /ASME OM-6 (Draft 11) as a guideline. Pump 7

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L vibration measurements will be obtained and recorded in velocity (inches per second) and;are broadband (unfiltered) peak readings. All monitored locations are clearly marked to identify the specific point at which the l transducer is to be placed while taking vibration measurements using portable equipment. The readout sysium and transducers used to take vibration measurements are capable of frequency response in the ra. ige of one-third minimum pump speed to at least one-thousand hertz, and they have a minimum accuracy over that range of 5%, with. the exception of the SBLC.

The SBLC pumps operate at 250 rpm. The low frequency response range L requirement of ASME (1/2 minimum pump shaft rotational speed) for these pumps is 2.1 Hz. The current vibration measerement system used at Dresden l is the Technology for Energy Corporation's (TEC) SMART Meter. The frequency range of this vibration mersuring system (includes the SMART meter, cable l and probe) is 2 to 10K Hz. When applying the OM-6 Draft 11 frequency response range criteria (1/3 minimum pump shaft rotational speed), the low frequency response range requirement becomes 1.4 Hz. Dresden knows of no l available equipment which has this low range ability (limited by probe performance).

Dresden Station proposes an alternate program which is believed to be l more comprehensive than that required by ASME Section XI. This program consists of performing the required vibration readings in velocity rather than mils of displacement. The technique of velocity measurement is an industry accepted method which is much more meaningful and sensitive to small changes that are indicative of developing mechanical problems.

Velocity measurements detect not only high amplitude vibrations that indicate major mechanical problems but also the equally harmful low amplitude - high frequency due to misalignment, imbalance, or bearing wear that usually go undetected by simple displacement measurements.

All centrifugal pumps in the IST Program will have vibration taken in a plane approximately perpendicular to the rotating shaft in two orthogonal directions on each accessible pump bearing housing. Measurement will also 8

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be taken in the axial direction on all bearing housings when accessible.

Reciprocating pumps will have vibration measurements taken approximately perpendicular to the crankshaft and the line of plunger travel, including the axial direction when accessible on each pump bearing housing.

Alternative Testino: Pump vibration measurements will be taken in vibration velocity (inches /second). The limit for vibration readings will not exceed ANSI /ASME OH-6 (Draft II) with the exception of the HPCI pumps.

The following vibration limits are applicable for 'all pumps at Dresden Units 2 and 3 with the exception of the HPCI pumps. The vibration limits for the HPCI pumps are specified in Relief Request PR-7.

TABLE PR-1 I-l RANGES OF VIBRATIONS.

ALERT RANGE PUMP TYPE LOW HIGH RE0VIRED ACTION RANGE Centrifugal >2.5Vref 6Vref >6Vref But not >0.325 in/sec But not >0.70 in/sec Reciprocating :2.5Vref 6Vref >6Vref i NOTE: Vref is the reference velocity in inches per second.

Any vibration measurement value below the low alert range is acceptable.

All of Dresden's Centrifugal pumps in the IST Program operate at a speed of greater than 600 rpm.

3.1.1.2 Evaluation. The vibratien monitoring program in ANSI /ASME OH-6, Draft'11, " Inservice Testing on Pumps in Light-Water Reactor Power Plants," through OMa-1988, Part 6, has been determined by NRC to be acceptable as an alternative to the requirements of Section XI, Paragraph IWP-4510, for vibration measurements in units of displacement. However, the licensee must comply with all the OH-6 vibration measurement requirements except those for which specific relief has been requested and granted.

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The licensee's' proposal differs slightly from that presented in OH-6 and is not described completely, for example; there is no discussion I

regarding how vibration measurements will be taken on vertical line shaft pumps. These differences have not been technically justified to show this proposal will provide adequate assurance of operational readiness for all pumps in the IST program. However, the licensee should be allowed to test these pumps utilizing the vibration monitoring program provided in OH-6.

This would give adequate assurance of operational readiness and provide a l reasonable alternative to the Code requirements.

1 The SBLC pumps operate at a very low speed, 250 rpm. It is impractical for the licensee to comply with the instrument frequency response range of OM 6 for these pumps. The instrumentation currently in use has a response  ;

range of 2 Hz on the iow end, which compares to'l.4 Hz, which would be J required by OM-6. It would be burdensome to require the licensee to obtain instrumentation with improved frequency response characteristics and this would not materially improve their ability to detect pump degradation.

Based on the determination testing pumps in accordance with the vibration program described in ASME/ ANSI OMa-1988, Part 6, provides a reasonable alternative to the Code requirements, relief should be granted provided the licensee utilizes all the criteria regarding vibration testing contained in ASME/ ANSI OMa-1988, Part 6. Additionally, based on the determination the OM-6 specified frequency response range is impractical and considering the burden on the licensee of complying with this range requirement, relief should be granted from the OH-6 response range requirement as requested for the SBLC pumps.

3.1.2 Relief Reouest The licensee has requested relief from the Section XI, Paragraph l IWP-3300 requirements to measure pump bearing temperature annually for all pumps in the IST program and proposed to measure pump vibration using a program patterned after OM-6, which utilizes measurement of pump vibration

, in units of velocity, quarterly.

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3.1.2.1 Licensee's Basis for Reouestino Relief. Searing temperature-measurements will not' provide significant additional information regarding bearing condition than that already obtained by measuring vibration.

Measurement of vibration provides more concise and consistent information with respect to pump and bearing condition. The usage of vibration measurements can provide information as to a change in the balance of rotating parts, misalignment of bearings, worn bearings, changes in internal hydraulic forces and general pump integrity prior to the condition degrading to the point where the component is jeopardized. Bearing temperature does not always predict such problems.

An increase in bearing temperature most often does not occur until the beaHng has detericrated to a point where additional pump damage may occur. Boaring temperatures are also affected by the temperatures of the medium being pumped, which could yield misleading results. Vibration readings are not affected by the temperature of the medium being pumped, thus the readings are more consistent.

Alternative Testina: Pump vibration measurements will be taken quarterly.

3.1.2.2 Evaluation. The licensee has requested relief from the Code requirements for annual bearing temperature measurements for all pumps -in their IST program. It is widely recognized pump bearing temperatures taken annually are unlikely to aid in the detection of bearing degradation and, L further, quarterly measurement of vibration displacement will be more likely to indicate bearing degradation.

As an alternative to annual measurement of pump bearing temperature,

[ the licensee has proposed to perform measurement of pump vibration in accordance with ANSI /ASME, OM-6, (see section 3.1.1.1 of this report). The OM-6 pump vibration testing program incorporates a sensitive vibration

! velocity measurement procedure in addition to monitoring at more locations on bearing housings. Performance of quarterly pump testing in accordance l

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- with '0H 6 has been demonstrated to provide better indication of pump l degradation than performing pump bearing vibration and annual measurement i of temperature in accordance with Section XI. The OM 6 pump vibration testing program facilitates an improvement in the ability to detect and monitor pump degradation and gives adequate assurance of pump operational readiness and provides a reasonable alternative to the Code requirements.

Based on the determination the licensee's proposal is essentially

. equivalent to and provides an acceptable alternative to the Code requirements, relief should be granted as requested.

3.1.3 Relief Reouest The licensee has requested relief from the test frequency requirements of Section XI, Paragraph IWP-3400, for all pumps'in the IST program and proposed to test these pumps quarterly.

3.1.3.1 Licensee's Basis for Reouestina Relief. Changes in hydraulic and mechanical pump parameters will not significantly change over the period of one month because the pumps are primarily run only for operability and remain in a standby mode of operation. Quarterly measurement of these parameters is more than adequate in determining pump degradation.

_ Alternative Testino: Pump parameters will be measured quarterly.

l 3.1.3.2 Evaluation. The licensee has proposed to test all pumps in their IST program quarterly, rather than monthly, as required by '

l- Section XI, 1977 Edition through Summer 1979 Addenda. All Editions of Section XI since 1980 have required pump testing to be performed quarterly. Additionally, most of these pumps are in standby systems and are operated only for inservice testing purposes or to satisfy Technical Specification system operability requirements. Running these pumps for inservice testing monthly causes unnecessary start cycles and wear to the pumps, requires additional testing personnel, and is therefore, burdensome to the licensee. The licensee's proposal to test these pumps quarterly l

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should provide adequate assurance of pump operational readiness and provides a reasonable alternative to the Code requirements. l Based on the determination the licensee's proposal provides a  !

reasonable alternative to the Code requirements and considering the burden  !

on the licensee if the Code requirements are imposed, relief should be

• granted as requested. J 3.2 Diesel Fuel Oil System 3.2.1 Relief Recuest The licensee has requested relief from the Section XI t Paragraph IWP 4200, requirement to measure suction pressure for the diesel fuel oil transfer pumps, 2-5203, 2/3-5203, and 3 5203, and proposed to evaluate those positive displacement pumps utilizing discharge pressure.

1.2.1.1 Licensee's Bjsis for Recuestina Relief. The Diesel Oil Transfer pumps do not have gauges installed to directly measure suction pressure required by ASME XI.

! Relief is requested from the requirement of measuring pump inlet pressure during pump tests. These pumps are utilized in transferring fuel oil from the diesel generator fuel oil storage tank to the diesel 'uel oil day tank. The configuration of the piping is such that the pump is located above the storage tank. The pump is a positive displacement gear type pump not requiring a positive suction head for proper operation. Since this l pump is a positive displacement type, the discharge pressure is independent of the suction pressure and, therefore,' inlet pressure data' is not important in evaluating pump performance.

Alternative Testi2q: Pump Discharge pressure will be set and flow will be measured. Vibration measurements will be recorded in accordance with PR-1 (see Section 3.1.1 of this report).

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I 3.2.1.2 Evaluation. These diesel oil transfer pumps are positive di vlacement type. Their outlet pressure is dependant on the pressure of i the system into which they are pumping and is not affected significantly by either inlet pressure or flowrate. For these pumos, differential pressure l

and flowrate are not dependant variables as they are for centrifugal type 1 pumps. Differential pressure is not a meaningful parameter in determining if hydraulic degradation is occurring. Measurement of pump discharge pressure and flow rate provides adequate information for evaluation of the hydraulic condition of these positive displacement pumps and presents a reasonable alternative to the Code requirements.

Based on the determination the licensee's proposed alternative is i essentially equivalent to the Code requirements, relief should be granted l as requested.

3.3 Diesel Generator Coolina Water System 3.3.1 Relief Reouest

, The licensee has requested temporary relief from the Section XI.

Paragraph IWP-4600 requirements for flow rate measurement for the diesel generator cooling water pumps, 2-3903, 2/3 3903, and 3 3903, and proposed to observe only pump flow rate until a later date when they will modify the affected systems to allow flow measurement in ecccMance with the Code requirements.

3.3.1.1 Licensee's Basis for Reauestino Relief. The Diesel Generator Cooling Water pump flow instrument is located after the heat exchanger and approximately 400 feet from the pump discharge. This arrangement has led to inaccurate and unstable readings such that relevant inservice testing i and trending cannot be performed, t

Dresden has established modification packages nos. M12 2 87-54, M12 3-87-54, and M12-2/3-87-21 for pumps 2-3903, 3 3903 and 2/3-3903 respectively. These modifications relocate the flow gauges to a proper location in their respective hydraulic circuits.

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Alternative Testina: Dresden will perform inservice testing and will set differential pressure, measure vibration and observe flow. No trending of flow readings will be made; however, determination of flow for the Diesel Generator Cooling Water pump will be performed by verification of l proper cooling of the Diesel Generator. Proper cooling is determined by l monitoring the inlet and outlet temperature and pressure oi' ihe dietal generator cooling water, verifying they are within the allowable ranges as specified in monthly surveillance procedure DOS 66001.

Upon successful completion of the modifications, flow measurements will l be performed and trended in accordance with ASME Section XI. At that time, l

this relief request will be deleted.

3.3.1.2 [y.Al uat ion. These pumps provide diesel cooling flow during operation of the generators. It is impractical to utilize the installed flow rate instrumentation for measurements and to trend and evaluate the results in conjunction with other measured IST parameters. Due to their system location the flow instruments for these pumps give inaccurate and l unstable readings which may result in declaring these pumps inoperable unnecessarily. 'This would be burdensome to the licensee. Precise flow rate instruments are necessary to accurately evaluate the hydraulic performance characteristics of these pumps to determine their operational readiness. The licensee has proposed to modify the systems for these pumps and install flow rate instruments which will allow compliance with the Code requirements. Also, the licensee has proposed to ensure these pumps provide adequate cooling flow to the diesels by monitoring cooling water inlet and outlet temperatures and pressure and ensuring they are within ranges specified in surveillance procedures during monthly diesel generator testing.

Monitoring the identified parameters for these pumps monthly should '

demonstrate their functional capability, until changes are made to the systems to allow compliance with the Code requirements. During the interim

, period the proposed testing should give adequate assurance of operational readiness and provide a reasonable alternative to the Code requirements.

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1 However, the proposed testing is not an acceptable long term sohtion, therefore, the modifications must be completed in a timely fashion to permit more comprehensive hydraulic evaluation.

Based on the determination the Code requirements are impracticable and the licensee's proposal provides a reasonable alternative to the Code requirements and considering the burden on the licensee if the Code

. requirements were imposed, interim relief should be granted until the end of the next scheduled refueling outage at which tine system modifications should be completed which allows pump flow rate measurements and evaluation in accordance with the Code requirements.

3.4 Standby Liouid Control System 3.4.1 Relief Reauest The licensee has requested relief from the Section XI, Paragraph IWP 3100, requirement to measure inlet pressure for the SBLC pumps, 2(3)A-1102 and 2(3)B 1102, and proposed to measure the test tank level (suction pressure source) prior to pump testing and to evaluate these pumps utilizing pump discharge pressure.

3.4.1.1 Licensee's Basis for Reouestino Relief. In the test mode, the SBLC pumps pump water from a test tank through a closed loop eack to the test tank. The level of the test tank is verified prior to each test. The tank is less than 5 feet high and therefore the maximum pressure developed by this head is less than 2 psig. The SBLC pumps take their suction from the bottom of the tank and therefore the suction pressure cannot exceed 2 psig.

The discharge pressure for the test is set at 1275 psig. The discharge pressure gauge reads in 10 psig increments. Two psig is not readable on this gauge and therefore the suction pressure is insignificant in this case. Also, since the reference suction pressure is approximately 1.3 psi, an extremely accurate and sensitive pressure gauge is needed to meet the Code requirements of having the full-scale reading of the gauge be less 16

1 than three times the reference value. This type of gauge becomes unreadable due to the reciprocating action of the positive displacement SBLC pumps.

Since the tank level is verified prior to testing, the only way to lose

)

suction pressure would be either if the suction line became plugged or if there was a line break in the test piping. In either case the 1275 psig discharge pressure would not be achieved and the test would be terminated and the pump declared inoperable.

1 Because of the reasons stated above, the requirements to record suction pressures for these pumps are not practical.

Alternative Testina: The level of the test tank will be monitored prior to each inservice test anc' the discharge pressure will be set at 1275 psig.

3.4.1.2 Evaluation. These SBLC pumps are positive displacement type.

Their outlet pressure is dependant on the pressure of the system into which they are pumping and is not affected significantly by either inlet pressure (providing adequate net positive suction head exists) or flowrate. For these pumps, differential pressure and flowrate are not dependant variables as they are for centrifugal type pumps. Differential pressure is not a meaningful parameter in determining if hydraulic degradation.is occurring.

The licensee's proposal to monitor test tank level and set pump

discharge pressure (set at 1275 psig) provides adequate information for use with flowrate to evaluate the hydraulic condition of these positive j displacement pumps and presents a reasonable alternative to the Code l

requirements.

Based on the determination the licensee's proposed alternative is l

essentially equivalent to the Code requirements, relief should be granted as requested.

17

3.5 Hiah Pressure Coolan't Iniection System 3.5.1 Relief Reouest The licensee has requested relief from the Section XI, Paragraph l IWP 4500, requirements for measurement of vibration in units of displacement (see also Section 3.1.1 of this report) for the high pressure coolant injection (HPCI) pumps, 2(3)2302, and proposed to utilize measurements in units of velocity (inches per second) and the ranges described below, l

l 3.5.1.1 Licensee's Basis for Reouestino Relief. During both Unit 2 and Unit 3 outages for 1988, the HPCI pump impellers were replaced with a newly designed impeller. This new impeller has cut the vibration levels in half on both the HPCI main and booster pumps. Even though the overall i vibration levels are much lower, in some cases the readings exceed the acceptable ranges established by Relief Request PR-1 and therefore ANSI /ASME OM 6.

The actual reference values and limits are documented in DAP 11-21 Form b, Technical Review of Pump Performance Parameters.

Alternative Testina: In reference to the letter dated September 1, 1988, " Safety Evaluation by the office of Nuclear Reactor Regulation Supporting IST Program Relief Requests, Commonwealth Edison Company,

, Dresden Nuclear Power Station, Unit Nos. 2 and 3, Docket Nos. 50-237 and i 50 249", Section 1.2., Relief Request PR-1A. Inservice Test Procedure, l

Temperature Measurement, this relief request is being submitted to establish velocity alert and action limits based on the actual pump vibration readings specific to these pumps.

The new vibration limits, though higher than those placed on the other pumps in the IST program, are modeled similar to the other limits in the L

18

program and are indicative of HPCI pump degradation. The vibration limits for each HPCI pump are listed below.

Alert Ranae Reauired Action Ranae l Low Hiah l i

Unit 2 HPCI

)

)

Main Pump Horizontal >1.5Vref to 2Vref >2Vref Main Pump Vertical >1.5Vref to 2Vref >2Vref  !

Booster Pump Horizontal >1.5Vref to 2Vref >2Vref Booster Pump Vertical >l.5Vref to 2Vref >2Vref Alert Ranae Reauired Action Ranae Low Hiah i

Unit 3 HPCI Main Pump Horizontal >1.5Vref to 2Vref >2Vref Main Pump Vertical >1.5Vref to 2.5Vref >2.5Vref Booster Pump Horizontal >1.5Vref to 2.5Vref >2.5Vref Booster Pump Vertical >1.5Vref to 2.5Vref >2.5Vref Vref is the reference velocity in inches per second.

NOTES:

Any vibration measurement below the alert range is acceptable.

3.5.1.2 Evaluation. These HPCI pump / booster pump combinations typically experience high levels of vibration. Strict adherence to the acceptance criteria of OH 6 may not be practicable since readings may routinely fall in the alert range, >0.325 inches per second (in/sec), and the pump may not be significantly degraded when vibration readings are only slightly greater than the required action limit of 0.70 in/sec, which is specified in OH 6. It may not be reasonable to require more frequent testing of a pump simply because the normal vibration levels exceed 0.325 in/sec and it may not be reasonable to require corrective action to be taken at 0.70 in/sec in every case.

19

The licensee has not assigned maximum required action limits for vibration velocity measurements taken on these pumps. Assigning required action limits based on multiples of reference values for vibration velocity, such as 2 or 2.5 times reference, may result in required action limits that are inappropriate. For example, a pump with a high reference value for vibration velocity of 0.5 in/sec could be considered operable with readings as high as 1.24 in/sec using these criteria. The pump might fail completely prior to reaching this value of vibration velocity. To ensure the pump is declared inoperable prior to failure, a maximum value of vibration velocity should be assigned which is based on a careful analysis of the pump specific design and installation. Some manufacturers consider pump vibration velocity readings as high as 1.0 in/see to be allowable for certain machines. Assigning limiting values of vibration velocity for these HPCI pumps that ensure corrective action is taken prior to pump failure is essential and would provide a reasonable alternative to the Code requirements.

Based on the determination the Code requirements are impracticable and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted provided the licensee assigns limiting values of vibration velocity to these pumps to ensure corrective action is taken prior to complete pump failure.

l 20 l

4. VALVE TESTING PROGRAM The Dresden Nuclear Power Station, Units 2 and 3. IST program submitted by the Commonwealth Edison Company was examined to verify that all valves included in the program are subjected to periodic tests required by the ASME Code,Section XI,1977 Edition through Sumer 1979 Addenda, 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 Commonwealth Edison Company basis for requesting relief from the valve testing requirements and the reviewers' evaluation of that request is summarized below and grouped according to the system and valve Category.

4.1 Various Systems 1

4.1.1 Eqwer Ocerated Valves '

4.1.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3413, stroke timing requirements for power-operated valves with maximum allowable full-stroke times less than or

! equal to 10 seconds (s.) and proposed to stroke time these valves to the l nearest second.

l 4.1.1.1.1 Licensee's Basis for Recuestino Relief--The NRC has evaluated and found acceptable later editions and addenda of ASME Section XI which provide a more practical approach to valve timing tolerances. Specifically, the same paragraph in the ASME Section XI,1980 Edition with Winter 1981 Addenda states:

l IWV-3413 Power Operated Valves (b) The stoke time of all power operated valves shall be measured to the nearest second, for stroke times 10 s or less, or 10% of the specified limiting stroke time for full-stroke times longer than 10 s. whenever such a valve is full-stroke tested.

21 1

It 'W To record stroke times to the nearest 10% of the maximum stroke time does not measurably increase the assurance of the ability of valves to perform their intended function, but does increase the administration burden and probability for recording errors.

Alternative Testino: The stroke time of all power operated valves shall be measured to the nearest second, for stroke times 10 s. or less, or 10% of the specified limiting stroke time for full-stroke times longer than 10 s., whenever such a valve is full-stroke tested.

4.1.1.1.2 Evaluation -The ASME Code,Section XI,1977 Edition with Addenda through Sumer 1979, requires stroke times to be '... measured I to the nearest second or 10% of the maximum allowable stroke time, whichever is less..." For valves with stroke time limits less than 10 s.

it may be impractical to measure v 've stroke time more accurately than the nearest second. For instance, a valve with a maximum stroke time of 2.5 s.

would need its stroke time musured to 0.25 s.; this may be difficult to  !

achieve due to operator response time considerations. Strict compliance with this Code requirement for valves with maximum stroke times less than 10 s. would be burdensome to the licensee. Measuring stroke times of valves that stroke in 10 s. or less to at least the nearest second should be adequate to evaluate valve condition, therefore, this testing provides a reasonable alternative to the Code requirements.

However, the requirements of this edition and addenda of the Code are not impractical for valves with stroke time limits greater than 10 s.

Valves with stroke time limits greater than 10 s. can have their full-stroke times measured to the nearest second in accordance with the provisions of the ASME Code,Section XI, Paragraph IW-3413,1977 Edition through Summer 1979, therefore this Code requirement is not considered unreasonable.

Based on the determination that it is impractical to comply with the Code stroke timing requirements for valves with maximum stroke times of 10 s. or less and considering the burden on the licensee if the Code 22 l

requirements are imposed, relief should be granted provided the licensee measures full-stroke times for all power operated valves in the IST program to at least the nearest second.

4.1.1.2 Relief Reauest. The licensee has requesteo relief from the l Section XI, Paragraph IWV 3413, requirement to compare stroke time measurements to the previously measured value for all power-operated valves with full-stroke times greater than 2 s. and proposed to stroke time these l valves and compare the stroke times to baseline values and assign alert limits based on these baseline values. Maximum valve full-stroke times will be assigned based on Technical Specifications or other documents.

4.1.1.2.1 Licensee's Basis for Reauestina Relief--Most air operated (AO) and motor operated (MO) valves have maximum stroke times that are much longer than actual stroke times. For example, M01301-3, Isolation Condenser Condensate Return Isolation Valve, has a maximum acceptable stroke time of 30 seconds but typically strokes in about 2 seconds. Stroke times could increase moderately (less than 50%) over successive tests and not trigger any closer observations, thus not allowing detection and corrective action. Degradation in such valves could then be severe before corrective actions would be taken (Source: Institute of Nuclear Power Operations' (INPO) July 1987 Evaluation of Dresden Station.

Page 37; Finding (TS.2-1).]

Errors have occurred with analyzing stroke times. Some valves with stroke times that have increased by over 50% from previous tests have not been placed in the Alert Range for closer observation and to allow detection and corrective action should further degradation occur.

Providing a known Alert Range and Maximum Stroke Time, will eliminate these errors.

Alternative Testina: In accordance with ASME Section XI, IWA-2240, l Dresden Nuclear Station has determined an alternative test method which is equivalent or superior to those of ASME Section XI, IWV 3413(c).

23

. l

. i Specifically, the test method provides for alternative valve timing, Reference Valves, Alert Stroke Time and Maximum Stroke Time for the valves tested in the IST Program. A summary of the determination of these timed action ranges are provided below.

Valves that require timing have their reference values established after the first normally scheduled inservice testing of these valves.

These valves tiining Reference Values shall then be added to their respective surveillance procedure's data sheet for use.

Stroke time Reference Values are established during the first normally scheduled inservice testing of the specific valve. These reference values are used to determine the alert stroke time limits. Maximum Stroke times for the valves tested in the IST Program are determined by the Technical Specifications. If Maximum Stroke Times are not included in the Technical Specifications, then the FSAR and valve manufacturer will be researched to establish the maximum stroke time. If maximum stroke times are unavailable in these documents, then a calculation will be performed for the establishment of the maximum stroke time. The details of this calculation are specified in the administrative procedure controlling the IST Program, Dresden Administrative Procedure (DAP) 11-21, Inservice Testing Program for Pumps and Valves.

The Alert Stroke Time limit fer each valve is determined as follows:

For valves with a reference value stroke time from 2 to 10 seconds, the Alert Stroke Time-limit is equal to 1.5 times the reference value. If the Alert Stroke Time limit calculated this way exceeds the Maximum Stroke Time, then the Alert Stroke Time is equal to 1.2 times the

! reference value.

l For valves with a reference value stroke time greater than 10 seconds, L

the Alert Stroke Time limit is equal to 1.25 times the reference value. If the Alert Stroke Time limit calculated this way exceeds the Maximum Stroke Time, then the Alert Stroke Time is equal to 1.15 times the reference value.

24

NOTE: In no case will the Alert Stroke Time Limit exceed the Maximum Stroke Time Limit.

4.1.1.2.2 Evaluation--The licensee has requested relief from the comparison of power operated valve stroke times from test to test as required by IW 3413 and proposed to assign power operated valve stroke time alert range limits based on valve baseline stroke times. The licensee has also proposed to use niant Technical Specification limits for the limi'ing value of full-stroke time allowed for these valves. If no ,

Technical Specification stroke time limit exists for a valve the manufacturer recommendations or other sources will be used.

An IST program which assigns both alert and limiting values of stroke time based on a valve's reference or baseline stroke time can give adequate assurance of valve operational readiness and provide a reasonable alternative to the Code requirements. However, assigning limiting values of valve full-stroke times based on plant Technical Specification system operability limits may not result in corrective action being taken for a valve that has seriously degraded and which may fail when called upon to perform its safety function. Therefore, plant Technical Specification valve stroke time limits may not be appropriate for use as IST limits. The licensee's proposal differs from the NRC staff position on assigning i

limiting values of full-stroke times to power operated valves as described j in NRC Generic Letter No. 89-04, Attachment 1. Position 5. Limiting values of full-stroke time should be assigned to power operated valves in l accordance with Generic Letter No. 89-04.

Based on the determination that the licensee's proposal to compare the measured stroke times to reference stroke time values and assign alert stroke time limits based on valve baseline stroke times is essentially equivalent to the Code requirements, relief should be granted, provided the licensee assigns limiting values of full-stroke time for all power-operated valves in their IST program in accordance with NRC Generic letter No.

89-04, Attachment 1, Position 5.

25

l

l 4.1.2 Containment Isolation Valves 4.1.2.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3420, requirements for leak testing Category A f and A/C primary containment isolation valves and proposed to leak test '

these valves in accordance with plant Technical Specification and 10 CFR 50, Appendix J, leak test requirements.

4.1.2.1.1 Licensee's Basis for Reauestina Relief.. Primary containment Category A isolation valves will be seat leak tested in accordance with the requirements of Technical Specification Sections 3.7 and 4.7 and 10 CFR 50, Appendix J. Failure to meet the maximum allowable leakage rates as defined by the Technical Specifications shall require compliance with ASME Section XI, IWV-3427(a).

Data trending, as required by IWV-3427(b) for valves 6 in, and larger, does not provide meaningful information that would justify the burden of taking corrective action. With the increased frequency, constraints would be placed upon the plant requiring extended shutdowns. Therefore, corrective action per IWV 3427(b) will not be used.

l Alternative Testina: Perform seat leakage testing in accordance with the requirements of 10 CFR 50, Appendix J, or as amended by Technical Specifications. The seat leakage results of the primary containment isolation valves will be analyzed in accordance with 10 CFR 50, Appendix J, j and Technical Specification Section 3.7 and 4.7.

Containment isolation valves will be repaired or replaced as required when the leakage rate exceeds the maximum allowable as stated in the Dresden Nuclear Station Technical Specifications or IWV-3427(a).

l 4.1.2.1.2 Evaluation--The licensee's has proposed to test these valves in accordance with 10 CFR 50, Appendix J, and plant Technical Specifications; upon exceeding the allowable limits of plant Technical Specifications or IWV-3427(a) the affected valve will be repaired or replaced.

26

The leak test procedures and requirements for containment isolation valves identified in 10 CFR 50, Appendix J. essentially meet the Section XI requirements since they incorporate all the major elements of Paragraphs IWV-3421 through -3425, however, 10 CFR 50, Appendix J, leak rate testing does not trend leakage rates or take corrective actions based on individual valve leakage rates. Testing containment isolation valves in accordance with 10 CFR 50, Appendix J, and complying with the Analysis of Leakage Rates and Corrective Action Requirements of Section XI Paragraphs IW 3426 and -3427(a), provides a reasonable alternative to the Code requirements as addressed in NRC Generic Letter No. 89 04, Attachment 1, Position 10, Containment Isolation Valve Testing.

Based on the determination that leak testing the containment isolation valves in accordance with the requirements of 10 CFR 50, Appendix J, and Section XI, Paragraphs IWV-3426 and -3427(a), Analysis of Leakage Rates and Corrective Action Requirements, provides a reasonable alternative to the Code requirements, relief should be granted from the requirements of IWV 3421 through -3425, and 3427(b), provided the licensee performs valve testing in accordance with NRC Generic Letter No. 89-04, Attachment 1 Position 10.

4.1.3 Excess Flow Check Valves 4.1.3.1 Relief Reouest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, requirements for exercising frequency and method, for all excess flow check valves, and proposed to perf7m check valve functional testing in accordance with plant Technical Specifications each refueling outage.

4.1.3.1.1 Licensee's Basis for Reauestina Relief--These are reactor process instrument line excess flow check valves that are tested in accordance with Technical Specification 4.7.D.I.B. requirements, which '

consist of a leakage test conducted every reactor refueling outt i. The testing involves uncoupling the instrument lines and verifying that each valve strokes to the closed position. The test also verifies that the 27

. . - -- . _ - - . .- .~ . . . - _ - - . . _. -. - - . _ .

4 .

valve limits flow to an acceptable level. These excess flow check valves <

are designed to automatically close in the event of a down stream line rupture. Valving operations and instrument line disconnections during the performance of the inservice testing can result in an emergency core  :

cooling system initiation or other automatic actuations during the time the vessel is pressurized. This would result in uncontrolled rapid pressure  ;

transients in the reactor. vessel and/or other undesirable consequences. .

The optimum time for the inservice testing of these valves is during reactor refueling.

Alternative Testina: The valves will be exercised during rector refueling in accordance with Technical Specification 4.7,0.1.B.

4.1.3.1.2 Evaluation -These are excess flow check valves on instrument sensing lines which penetrate the primary containment. Their function is to close in case of excessive flow to perform a containment isolation function. The testing specified in Dresden Technical Specifications is a modified leak test which is performed once each reactor refueling outage. Performance of valve closure verification on a quarterly or cold shutdown basis is impractical since this would isolate various

! instruments and could result in loss of control signals to vital

! instrumentation and subsequent unnecessary initiation of automatic safety systems, etc. Given these concerns, testing these valves each quarter or

! during cold shutdowns would be burdensome to the licensee. The licensee's proposal to leak test these valves each reactor refueling outage utilizing

~

the procedures and acceptance criteria outlined in the plant Technical Specifications gives adequate assurance of operational readiness and j provides a reasonable alternative to the Code reouirements.

Based on the determination that compliance with the Code requirements is impractical, the licensee's proposal provides a reasonable alternative to the Code rcquirements, and considering the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

28

l

. l 4.2 Control Rod Drive System

{

4.2.1 Cateaory A Valves 4.2.1.1 Relief Reauest. The licensee hs requested relief from the Section XI, Paragraph IWV 3413, requirements for stroke timing the control rod drive (CRD) alternate rod insertion (ARI) anticipated transient without scram (ATWS) air header bleed valves listed below and proposed to exercise these valves without stroke timing each cold shutdown.

l Valve Identification Valve Identification 2 -0339 524A 2 0339 524B 2 -0339 548A 2 0339 548B 2 -0339-549A 2 0339 5498 4.2.1.1.1 Licensee's Basis for Reouestina Relief--These valves are part of the ARl/ATWS system. These solenoid operated valves provide an alternate method of relieving the CRD scram air header of air pressure so as to provide CRD insertion. Exercising these valves results in the insertion of all the control rod drives. This is not considered practical during normal operation.

l These 1/2" valves operate too rapidly and there is no position indication for any practical timing measurements. Their operational readiness and safety-related function are verified during Reactor j Refueling. Additional testing for valve timing is considered impractical.

Alternative Testina: These valves will be exercised, without timing, I

and verify proper operation and venting during Cold Shutdown.

4.2.1.1.2 Evaluation--These are fast acting solenoid valves which open to vent the CR0 air supply header, which supplies pressure to keep the scram valves closed, to ensure valves 2(3)-0305126and-127opensothat the control rods insert upon a scram signal. These valves are part of the ARI/ATWS system. It is impractical to stroke time these valves since they are enclosed and the stem cannot be observed and they are not equipped with l

1 l

l 29 l

1

-. . - - . - ~ _ - - . - . . . - - . _ _ - _ _ _ _ _ - - -

1 f external valve position indication. Measuring stroke times for these '

valves would require system redesign or installation of special test i equipment which would be burdensome to the licensee. Exercising these valves results in the insertion of all control rods and is impractical quarterly during power operation since it would result in a plant shutdown. These valves can be exercised during cold shutdown, however, no reasonable method can be used to obtain meaningful stroke times. The licensee's proposal to verify proper operation during cold shutdown without stroke timing should give adequate assurance of valve operational readiness provided it verifies each valve can accomplish its function in a timely manner and suitable acceptance criteria are assigned so that if valve operability is questionable, corrective action is taken. This would then provide a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical, and considering the licensee's proposal and the burden on the licensee if the Code requirements are imposed, relief should be granted provided the licensee verifies each of these valves is capable of performing its safety function in a timely manner and assigns appropriate acceptance criteria for determination of operability.

4.2.1.2 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3413, requirements for stroke timing the CRD backup scram and scram dump valves listed below and proposed to exercise these valves without stroke timing each during cold shutdown.

Valve Identification Valve Identification 2(3) 0302-19A 2(3)-033919B 2(3)-0302-20A 2(3)-0339-208 4.2.1.2.1 Licensee's Basis for Reauestino Relief--Exercising these valves results in the insertion of all the control rod drives. This is not considered practical during normal operation.

These 1/2" valves operate too rapidly and there is no position indication for any practical timing measurements. Their operational 30

readiness and safety related function are verified during Cold Shutdown.

Additional testing for valve timing is considered impractical.

Alternative Testina: These valves will be exercised, without timing, and verify proper venting during Cold Shutdown.

4.2.1.2.2 Evaluation--These are fast-acting solenoid valves which 3 open to vent the CRD pilot air supply header to ensure valves 2(3)0305126  !

and -127 open to insert the control rods upon a scram signal. It is impractical to stroke time these valves since they are enclosed and the stem cannot be observed and they are not equipped with external valve position indication. Obtaining accurate stroke times for these valves 4 would require system redesign or installation of special test equipment i which would be burdensome to the licensee. Exercising these valves results in the insertion of all control rods and is impractical quarterly during power operatf since it would result in a plant shutdown. These valves l

, can be em nrd during cold shutdowns, however, accurate stroke timing is l

, not practo J.e. Exercising these valves each cold shutdown and ensuring they operate in a reasonable time, with suitable acceptance criteria assigned, should give adequate assurance of valve operational readiness and provide a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical, and considering the licensee's proposal and the burden on the licensee if the Code requirements are imposed, relief should be granted provided the licensee verifies each of these valves is capable of performing its safety function in a timely manner and assigns appropriate acceptance criteria for determination of operability.

l 4.2.2 [ateaory B & C Valves 4.2.2.1 Relief Reouest. The licensee has requested relief from the L Section XI, Paragraph IWV-3413 and -3521, requirements for exercising and j stroke timing the CR0 scram inlet and outlet valves, 2(3) 305-126, 127, 31

i .

.~

and -114, and CRD scram pilot valves, 2(3) 305 117 and -118 and proposed to verify proper operation of these valves via plant Technical Specification scram testing.

4.2.2.1.1 Licensee's Basis for Raouestina Relief--To exercise these valves requires scramming the individual CRDs.

The proper operation of each of the valves is demonstrated by .ne Technical Specification required scram testing. To exercise these valves more than the current Technical Specification requirements is not practical.

These valves are exercised and each individual control rod drive scram insertion is timed and must meet specific time increments as stated in the Technical Specifications. This individual rod timing ensures that the valves function properly.

Alternative Testina: Individual scram insertion tim 0s and subsequent valve exercising will be performed per the Technical Sp6cification requirements. The required frequency is as follows:

After each refueling outage, prior to operation greater than 30 percent of rated thermal power, all control rods shall be subject to scram time tests from the fully withdrawn position with reactor pressure above 800 psig; and At 16 week intervals, 50% of the control rod drives shall be tested so that every 32 weeks, all the control rods shall have been tested.

4.2.2.1.2 Evaluation--These valves cannot be exercised without causing the associated control rod to scram and they must operate properly in order that the associated control rod meets the scram insertion time limits provided in the plant Technical Specifications. Their operational readiness is verified by scram timing the control rods. It is impractical l

l 1

32

l to exercise all these valves each quarter since this requires scraming each control rod quarterly, which increases wear of the control rods and I subjects the reactor core to many rapid reactivity transients. The licensee's proposal to exercise these valves during Technical Specification i CRD testing, which tests 50% of the CRDs each 16 weeks, and 100% after a reactor shutdown prior to operation with reactor power greater than 30% l gives adequate assurance of valve operational readiness and provides a l reasonable alternative to the Code requireaents.

1 The alternate exercising frequency required by Technical Specifications has been previously approved by the NRC staff to reduce wear on the control I rod drive mechanisms and to reduce the number of rapid reactivity transients to which the reactor core is subjected. Based on the l

determination that compliance with the Code requirements is impractical and the licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted as requested.

4.3 Main Steam System 4.3.1 Cateoorv AC Valves i

4.3.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3522, requirement to measure check valve force or torque for the main steam relief valve discharge piping vacuum breaker check valves, 2(3)-0220 105A, -105B, -105C, -105D, and -105E, and proposed to manually full-stroke exercise the valve disks and visually inspect the valve internals during those cold shutdowns when the containment is de inerted and each refueling outage.

4.3.1.1.1 Licensee's Basis for Reauestina Relief--These valves provide vacuum relief on the main steam electromatic and target rock relief valve piping to the torus. They are normally closed and are required to open when steam is blown down to the torus. The steam condenses and creates a vacuum.

33

The requirements of IWV-3522 to measure the force or torque used by a mechanical exerciser to move the disk is not applicable in this case l because the valve does not have a manual exerciser and can only be exercised by reaching into the valve and pushing the disk off the seat.

These valves are designed to open on a differential pressure of less than 1 psid and therefore manually exercising the disk requires only slight hand pressure. Obtaining and adapting a device to measure the force exerted on the disk while exercising it is impractical.  !

Alternative Testina: These valves will be manually full stroke exercised during each cold shutdown when the drywell is de-inerted. l Additionally, since the valve internals are visible without disassembly, the valve disk, seat, pin, and spring will be visually inspected during the stroke test.

4.3.1.1.2 Evaluation -These vacuum relief valves are located inside the primary containment which is inerted with nitrogen during power operation and during some cold shutdowns. Exercising these valves requires entry into containment. It is impractical to perform this testing quarterly during power operation or during cold shutdowns when containment is inerted because of the personnel safety hazard posed by the oxygen deficient atmosphere. Purging and re-inerting containment is costly and could result in delay of plant startup from cold shutdown, which would be burdensome to the licensee. Exercising these valver during cold shutdowns when containment is deinerted and at each refueling outage should give adequate assurance of operational readiness and provides a reasonable alternative to the Code requirements.

The licensee has stated " Obtaining and adapting a device to measure the force exerted on the disk while exercising it is impractical." Their proposal to full-stroke exercise the valve disks and inspect the valve l internals (i.e., disk, seat, pin, and spring) at each exercise as an alternative to measuring the force or torque required per IWV-3522 should l give adequate assurance of operational readiness.

34

l

\

.~.

Based on the determination that compliance with the Code requirements is impractical, the licensee's proposal provides a reasonable alternative to the Code requirements, and considering to the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

4.3.2 Cateaory BC Valves 4.3.2.1 Relief Recuerl. The licensee has requested relief from the Section XI, Paragraph IW 3413, requirement to measure stroke time of the main steam automatic depressurization system (ADS) Target Rock, 2(3)-0203 3A, and electromatic relief valves, 2(3)-0203-38,-3C,-3D, and -3E, and proposed to full-stroke exercise and verify proper valve operation by monitoring turbine or compensating valve position for appropriate response on the return to operation from refueling outages.

4.3.2.1.1 Licensee's Basis for Reauestina Relief--

Valve Timing:

Relief is requested for the timing requirement for these valves. These valves provide steam blowdown (relief) to the torus which is initiated either automatically or manually by the use of a key operated switch.

Because of the ability to be manually operated, they are categorized as both "B" and "C" valves.

l These valves are exercised once each operating cycle with the reactor at pressure. Each valve is manually opened and is verified open by a compensating turbine bypass valve or control valve closure. Consistent I

timing of this event for the purpose of determining the operational

{ readiness of these valves is not considered practical.

l Valve Exercising:

The relief valve discharges at one location in the torus and should the valve remain open for longer than five minutes, there is a concern that the 1

35

l

)

,. 1 extended blowdown at a given point could overheat the water locally, I resulting in the release of free steam. This can create localized problems with the interior coating.

4 l Manually exercising these valves requires steam pressure behind the disk before cycling and thus must be performed with the reactor at pressure. Thus, the plant must be in an operating or startup condition with the required steam pressure in the main steam lines, j Additionally, under IST Category C safety valve and relief valve tests. l all these valves are rebuilt every other outage or approximately 36 months. J Dresden Station believes the combination of rebuilding (once every 36 months) and insitu exercising (once each operating cycle) adequately verifies the valves operational readiness. '

Alternative Testino: These valves will be full stroke exercised without timing at least once per operating cycle in accordance with Technical Specification 4.5.D.l.b.

4.3.2.1.2 Evaluation--The Target Rock ADS valves, 2(3)-0203-3A, act both as power operated valves in response to an automatic control signal and as safety relief valves. As a result, these valves should be tested to both the Category B and C requirements. The electromatic ADS valves, 2(3)-0203-3B, -30, and -3D, act only as power operated relief valves.

Full-stroke exercising these valves quarterly during power operations is impractical as this may result in a loss of-coolant accident. NUREG 0626

" Generic Evaluation of Feedwater Transients and Small Break Loss-of-Coolant Accidents in GE Designed Operating Plants and Near Term Operating License Applications" recommends reduction of challenges to relief valves to lessen i the risk of Small Break LOCA (see also NUREG 0737,Section II.K.3.16).

To full-stroke exercise these valves requires reactor steam pressure and is not practical during cold shutdowns when the reactor pressure is low. Accurate stroke tinies for these valves cannot be obtained since their stroke times are on the order of 100 milliseconds and there is no direct position indication. The licensee has proposed to exercise these valves 36

1

' i once each operating cycle with the reactor at power by passing reactor steam i through the valves and to verify the valve opens by monitoring turbine bypasa and control valve position. This testing along with rebuilding these ,

valves every other refueling outage provides an acceptable level of quality and safety and a reasonable diernative to the Code requirements.

Based on the detemination that compliance with the Code requirements is impractical and considering that the licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted as requested.

4.3.2.2 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV 3512, requirement to check set points of the main steam automatic depressurization system (ADS) Target Rock, 2(3)-0203-3A,and electromatic relief valves, 2(3) 0203-38, -30, -3D, and -3E, and proposed to calibrate the pressure switches and to full-stroke exercise and verify proper valve operation via turbine or compensating valve position each refueling outage, l

4.3.2.2.1 Licensee's Basis for Reauestina Reliif--The I

electromatic relief valves and the relief function of the target rock valve are operated by actuation of a pilot solenoid valve which opens the main 1 valve by creating differential pressure across the main disk. The pilot valve is actuated from an electric signal from either a control switch, the auto depressurization logic, or a pressure switch that senses reactor system pressure.

The requirement of IWV-3512 to check relief and safety valve set points in accordance with ASME PTC-25.3 1976 is not applicable in this case because the set points are established by calibrating the pressure switch which senses system pressure. Therefore, relief is requested from compliance with this requirement.

l l

l The pressure setpoint of these valves is set by calibrating the pressure switch rather than testing the complete valve assembly. The combination of the pressure switch calibration and the exercising test for operability (BT) satisfies the intent of paragraph IWV-3512.

37

~.'

Alternative Testino: The pressure switch for eacn of these valves will j

be calibrated to verify the correct setpoint and the exercise test in j

accordanct. with Technical Specification 4.5.D.1.b. will verify operability l

of the valve. '

4.3.2.2.2 Evaluation--The relief function of all these valves is '

initiated by energizing their associated pilot solenoid valves. These are P

actuated by electrical signal from a pressure sensing device on the main steam line. The open safety function of the Target Rock safety / relief valve, 2(3)-0203-3A, is initiated by steam pressure above the pressure setpoint, which lifts the valve against spring pressure. This function of the Target Rock valve is not verified by setpoint calibration of the pressure switch at any frequency. However, these Target Rock valves are rebuilt at least once every 36 months and setpoint tested after re assembly in accordance with ASME PTC-25.3-1976, therefore, relief is not necessary for the safety function of this valve.

The rPief function of all these valves are controlled by pilot valves. Except for the Target Rock safety function described above, these valves need not be tested to the ASME PTC 25.3-1976 requirements. The licensee's proposal to verify the relief function of all these valves by verification of setpoint setting and Technical Specification exercising gives adequate assurance of operational readiness and provides a reasonable alternative to the Code requirements.

Based on the determination that the licensee's proposal provides a i reasonable alternative to the Code requirements, relief should be granted from the requirements of IWV-3512 except for the Target Rock valves which are tested in accordance with IWV 3510 to verify their safety valve function.

4.3.2.3 fLelief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3512, requirement to check the as-found set points of the main steam ADS Target Rock safety relief valves, 2(3)-0203-3A,and 1

38

-proposed to replace the pilot assembly section of the valves each refueling <

with a rebuilt and tested assembly and to replace the main valve body every other reactor refueling outage.

4.3.2.3.] Licensee's Basis for Reauestina Relief--There is one main steam Target Rock safety relief valve on each unit. These valves have their pilot assembly replaced with a rebuilt and tested assembly every Reactor Refueling outage. The main valve body is replaced every other Reactor Refueling outage.

To perform as-found testing of the one valve when the pilot assembly is being replaced with a rebuilt and tested assembly is impractical.

Alternative Testina: Therefore, these valves will have their pilot assembly replaced with a rebuilt and tested assembly every Reactor Refueling outage and the main valve body will be replaced every other Reactor Refueling outage.

4.3.2.3.2 Evaluation -These valves perform both safety and relief functions. The Code requires testing of these valves once every five j years. The licensee has proposed to replace these valves' pilot assemblies with similar assemblies that have been rebuilt and setpoint tested at each refueling outage, which is more frequently than required by the Code.

However, failure to check the relief valve "as-found" setpoints could allow significant setpoint drift to go undetected. Whereas it is inconvenient to perform setpoint "as-found" testing on these valves after they are removed from the system, it is not considered impractical or excessively burdensome. Also, the licensee's proposal does not provide a reasonable alternative to the Code requirements since it may not monitar degradation that is affecting the valve's setpoint mechanism and does not give adequate assurance of operational readiness and provide a reasonable alternative to the Code requirements.

Since compliance with the Code requirements is not impractical and the licensee's proposal does not provide a reasonable alternative to the Code L requirements and considering the burden on the licensee if the Code I requirements were imposed, relief should not be granted as requested.

l 39

4.3.3 Cateaory C Valves 4.3.3.1 Relief Reouest. The licensee has requested relief from the Section XI, Paragraph IW-3513, requirement for test sample expansion for the main steam safety valves, 2(3)0203-4Athrough-4H,andproposedto replace one half of these valves each refueling outage with rebuilt and tested assemblies so that all valves are tested or replaced with tested valves at least once every 36 months.

4.3.3.1.? Licensee's Basis,for Reouestina Relief--Dresden Technical Specif', cation Surveillance uquirement 4.6.E. provides that a minimum of 1/2 of all safety valves shall be bench checked or replaced with a bench checked valve each refueling outage. ASME requirss that N/60 x Total No. of safety relief valves be tested, where N is the number of months between outages.

Dresden's existing program replaces 1/2 of 8 valves or 4 valves per outage per unit. Every other outage or every 36 months, all of the valves will have been tested or replaced with cleaned, rebuilt valves, which have verified set points.

ASME Section XI requires that 18/60 X 8 or 2.4 valves be tested per cutage per unit. All valves will have been tested at least once every 60 months. ASME Section XI requires a sample expansion testing program of an additional 2.4 valves (in Drcsden's case) when any valve in a system fails to function properly during a regular test.

Dresden Station has review 2 the ASME Section XI IST sample expansion requirements and believes that the frequency of removal and maintenance of these valves on an accelerated basis provides adequate assurance that these valves will perform safely and reliably.

Alternative Testina: Dresden Station will remove and rep 1. ace with rebuilt safety valves every refueling outage,1/2 of the totn number of Main Steam safety valves. This means that all Main Steam safety valves wiil be replaced with rebuilt safety valves every other refueling outage or 40

approximately every 36 months. Therefore, should any of the 4 removed valves fail as-found testing, no sample expansion will be performed.

4.3.3.1.2 Evaluation--The Code requires testing of these main steam safety valves at'least once every 5 years. The Code formula (N/60 X the total number of valves equals the amount that must be tested at at each refueling outage) requires that 2.4 valves be tested every refueling outaoc for Dresden. If any valve fails to function properly during a regu6 ust the Code requires testing of additional valves (sample expansion) which would require expanding the sample and testing a total- of 4.8 valves in this case. o

~

i The licensee has proposed to test or replace 4 of their 8 valves (per plant) with valves that'have been rebuilt and setpoint tested each refueling outage, 18 months. This exceeds the number of valves that must '

be tested per the Code requirements (18/60 X 8 valves - 2.4 valves) each  !

18 months and is only one valve short of the amount that would need to be tested as part vf an expanded sample (in an expanded sample the licensee would be required to test a total of 4.8 (5) valves). Although the licensee's proposed regular testing frequency is conservative when compared to the Code required frequency, it may be non-conservative if any tested

! valve fails the "as-found" setpoint test. Further, if one valve fails the setpoint-test only one more valve (in addition to the 4 regularly tested t valves) would require testing, which would not place an excessive burden on

.the licensee. The licensee's proposal may not give adequate assurance of

operational readiness and does not provide a reasonable alternative to the-Code requirements.

Since compliance with the Code requirements is not impractical and the licensee's proposal does not provide a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were-imposed, relief should not be granted ts requested.

4<3.3.2 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency requirement for the main steam isolation valve (MSIV) operating air accumulator check valves listed l

l 41 l 1

, . j below and proposed to full-stroke exercise these valves open and closed' '

each refuelingLoutage.

Valve Identification Valve Identification Valve Identification L 2-0220 85A~ 2(3)-0220-84A 3-0220 83A l 2 0220-85B 2(3)-0220848 3-0220-83B I- 2-0220-850 2(3)-0220 840 3-0220-83C 2-0220 85C 2(3)-022084D 3 0220 83D 4.3.3.2.1. Licensee's Basis for Reauestino Relief--The MS!V accumulator check valves are normally open and are required to close upon loss of the pneumatic system. The only practical method of exercising.

these valves closed is by backpressurizing the check valve and verifying t the valve closed by observing no significant loss of pressure (leak rate test).

Verifying closure of these valves during power operation or cold shutdown requires deinerting and entering the drywell and X-area to perform the appropriate leak rate tests. The average dose rates for these areas is 1500 millirem per hour during normal operation and 300 millirem per hour during cold shutdown periods. These dose rates are considered to be extremely * - "ditionally, to perform the necessary leak test, an L extensive at: at of accumulator piping must be disassembled to isolate the check va*.es. This e-tensive maintenance will delay unit startup if the unit is s ol d .e ' t This test is impractical to perform during normal c v n. .

m io shutdown due to the dose considerations and the burden m.m the MSIV accumulator piping.

Alternative testina: The valves listed in section 2.1 (listed above in

, Section 4.3.3.2 of this report) will be exercised open and closed each

! reactor refueling.

4.3.3.2.2 fvaluation -These valves are located inside the primary containment, they shut to maintain air pressure in the MSIV accumulators upon loss of pressure in the supply header. It is impractical to verify the closure capability of these valves quarterly or during cold shutdowns since this requires isolating the air supply, disconnecting accumulator piping, and bleeding pressure from the associated instrument air header.

42

I This- testing would result in exposing personnel to high radiation dose l rates, is very time consuming, and may delay startup from cold shutdown.

The valves necessary to test these valves are in the primary containment, which is inerted during power operation and is not always de inerted at cold shutdown. Te de inert the containment during each cold ,

shutdown te tut ttese valves would be costly and time consuming to the  !

licensee u d co @ result in a delay in returning to power, which would be .j burdeM ae t6 the' licensee. The licensee's proposal to full-stroke crercise these valves open and cle!cd each refueling outage gives adequate- 1 tssurance of operational readiness and provides a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's-alternative testing proposal, and the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

4.4 Hiah Pressure Coolant In.iection System 4.4.1 Cateoory C Valves 4.4.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, requirement to full-stroke exercise (open) the high pressure coolant injection (HPCI) torus suction check valves, 2(3)-2301-39, and proposed to part-stroke exercise these valves open with '

flow quarterly and verify their full-stroke capability by perforr,ing sample disassembly and inspection each refueling outage.

4.4.1.1.1 Licensee's Basis for Reauestina Relief--To full-stroke exercise this valve open requires a flow test using suppression pool (torus)waterastheHPCIpumpsuction. The normal test flow path uses the condensate storage tank (CST) as the pump suction rather than the torus.

The torus is not used as the HPCI pump suction for testing because the 43

i

• =

system test loop is not designed to recirculate _ water from the torus to the torus.

The only flow path available to verify full flow valve operability would involve pumping torus water to the CST. Since torus water is  !

untreatable, low quality water and the CST water is demineralized, the tank would have to be drained (approximately 100,000 gallons), flushed and refilled to restore water chemistry back to specifications after each test. This testing would be extremely burdensome because of the time involved in draining and refilling the CST and processing the large amount i of waste water that would be generated.  !

Alternative Testina: The valves listed in section 2.1 (2(3)-2301-39] i will be disassembled and inspected on a refueling outage basis to verify valve operability. The disassembly and inspection will be performed in accordance wiW the sampling technique discussed in the IST Program submittal.

The valves in section 2.1 (2(3)-2301-39] will also be partial stroke exercised in conjunction with the HpCI pump operability test each quarter. <

4.4.1.1.2 Evaluation--This check valve must open to allow HPCI suction from the suppression pool (torus). It is impractical to full-stroke exercise this v61ve with flow quarterly during plant operation, during cold shutdown, or during refueling outages since this would result in chemical contamination of the CST water (the only available full-flow path other than the reactor coolant system) due to the contaminants present in the torus water. Restoring the chemistry of the CST water 1 (approximately 100,000 gallons) would be very expensive and time consuming and constitute a significant burden to the licensee. The-licensee has proposed to part-stroke exercise this valve quarterly with a small amount of flow through a 3/4 inch drain line. However, it is unlikely that this

] minimal amount of flow could fully open this 16 inch check valve.

Disassembly, inspection and manual full-stroke of the valve disk cari adequately ascertain a check valve's internal condition. However, the NFC 44

staff considers this to be a maintenance procedure with inherent risks,

/

l which should be used in lieu of testing only when no testing method is feasible, and which should always be followed by a part-stroke exercise with-flow. Disassembly and inspection should be ,,erformed under a plant maintenance program at a frequency commensurate with the check valve type and service. .The licensee's proposed sample disassembly and inspection program should adequately determine valve condition and provides a reasonable alternative to the Code requirements. If the licensee feels that an extended inspection interval is warranted, this should be justified in a resubmittal.

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

4.4.1.2 Relief Reauell. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency and test method requirements for the HPCI keep fill check valves, 2(3)-2354-500 and proposed to verify the full-stroke exercise (closed) capability of these valves by performing sample disassembly and inspection as described in their IST program. In addition, a series stop check valve will be manually operated to verify its closure capability quarterly.

4.4.1.2.1 Licensee's Basis for Reauestino Relief--Exercising closed the HPCI keep fill check valves quarterly is not possible since the downstream valve (2354-501) is also a check valve (two check valves in series) and can not be back pressurized during normal HPCI pump testing.

Valves 2(3)-2354-500A and B can not be verified closed independently of the 2(3)-2354-501A and B by any direct or indirect method during norcal operations or cold shutdown periods because the connections between the valves do not exist.

Valves 2(3)-2354-501A and B are verified closed each quarter by closing the valve handwheels.

45

.: j Alternative Testina: The valves listed in section 2.1(2(3)-2354-500) will be disassembled and inspected on a refueling outage basis to verify valve operability in accordance with the sampling technique discussed in DAIM-V22.

4.4.1.2.1 Evaluation--Valves 2(3)-2345-500 are in series with stop check valves 2(3)-2345-501 and function in the closed position to prevent diversion of HPCI flow. It is impractical to verify valves 2(3)-2345500 closed either quarterly or during cold shutdowns since they have no provision for external verification of valve position (i.e.,

positionindicators,pipetaps). Installation of instrumentation to verify valve position would involve system redesign and be burdensome to the

^ licensee. However, the licensee can verify that the downstream in-line stop check valves operate to the closed position using the handwheel quarterly, which gives greater assurance that the pair will perform its safety function.

It is impractical to individually test valves 2(3)-2345-500in l accordance with the Code requirements. The licensee has proposed to perform sample disassembly and inspection on these valves during refueling outages to verify their operational readiness, however, this method should be used only as a last resort, where no other method can reasonably be utilized. A practical method that will adequately verify the reverse closure capability I of these series check valves [2(3)-2345-500 and -501) would be leak testing the pair at least once each' refueling outage. If excessive leakage is noted then both valves should be repaired or replaced as necessary. This testing in addition to quarterly exercising of valve 2(3)-2345-501 gives reasonable assurance of component operational readiness and provides a reasonable I

alternative to the Code requirements.

l Based on the determination that compliance with the Code requirements l 1s impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted l provided the pair of series check valves is leak tested at least each refueling outage. If excessive leakage is noted, both valves should be repaired or replaced as necessary.

46

4.4.1.3 Relief Reauest. The licensee has requested relief from the  !

Section XI, Paragraph IW-3521, test frequency and test method requirements l for the HPCI turbine exhaust _ vacuum breakers, 2(3)-239976A,-768,-77A,and

-778, and proposed to verify the full-stroke exercise capability of these '

valves by performing sample disassembly and inspection as described in their

! IST program, i

l 4.4.1.3.1 Licensee's Basis for Reauestino Relief--To full-stroke l

exercise these valves open/ closed requires entering the torus and disassembling and manually exercising the valves to verify operability.

This testing is impractical during' power operations since these valves are located inside the torus and are inaccessible because the torus is inerted and at a negative pressure. To perform a full-stroke exercise of these

}. valves during cold shutdowns is extremely burdensome because entering the torus requires removal of the 4.0 ft, diameter manway cover. Once the cover is replaced after testing, a local leak rate test must then be performed to verify the primary containment boundary. This added maintenance and testing burden would invariably delay unit startup.

' Alternative Testina: The valves listed in section 2.1 [2(3)-2399 76A,

-768, -77A, and -778) will be disassembled and inspected to verify valve operability in accordance with the sampling technique discussed in the IST Program submittal.

4.4.1.3.2 Evaluation--These series-parallel check valves open to relieve the vacuum created by condensing steam in the turbine exhaust line and close to prevent steam heating of the torus airspace. It is impractical to individually verify a full-stroke exercise of these valves quarterly during power operation, during cold shutdowns, or during refueling outages because.there are no test taps or external position indicating devices to allow this verification. A system modification would be necessary to permit individual valve testing, which would be expensive and burdensome to the licensee..

Disassembly, inspection and manual full-stroke of the valve disk can adequately ascertain a check valve's internal condition. The NRC staff considers this to be a maintenance procedure with inherent risks, which 47 w

u uuI I I '

should be used in lieu of testing only when no testing method is feasible, and which should always be followed by a part-stroke exercise with flow.

Disassembly and inspection should be performed under a plant' maintenance program at a frequency commensurate with the check valve type and service.

The licensee should actively pursue non-intrusive methods of testing this set of four series-parallel check valves to verify the set will function in the forward and reverse flow directions at least each refueling _ outage as an alternative to disassembly and inspection. Alternate test methods should be

- considered such as, connecting an air line to the inlet pipe and using air flow to verify the set's open capability, hooking up a vacuum pump and drawing a vacuum on the set to verify set closure capability, or installing a thermocouple near the inlet pipe to detect the high temperature associated with steam leakage back through the valves.

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted either as requested, or to functionally test the valve set in both the open and closed direction each refueling outage. When these valves are tested as a set, if either the forward flow or reverse flow closure capability of the set becomes questionable, all valves in the group must be declared inoperable and be repaired or replaced.

4.4.1.4 Relief Reoqgit. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency requirements for the HPCI injection check valves, 2(3)2301-7, and proposed to part-stroke exercise these valves open during cold shutdown and full-stroke exercise them open and closed each refueling outage.

4.4.1.4.1 Licensee's Basis for Reauestina Relief--The HPCI check valves have both an open and closed safety function. These valves are required to be closed during normal power operati,n to prevent flow diversion of reactor coolant (feedwater). These valves are also required to open upon a HPCI initiation to provide the injection path for HPCI.

48

To-full-stroke exercise th' ese valves open quarterly or during cold shutdowns requires injecting approximately 5,000 gpm of condensate storage  :

tank water at 70*F into the reactor vessel at 540*F. This type of test is. impractical because repeating this test will eventually fatigue and crack the injection nozzles due to the induced thermal shock. In addition to the nozzle cracking concerns, a cold water transient'in the vessel will cause a reactor trip.

A reverse flow test (back pressurizing) is required to verify the closed position of the.HPCI injection check valves. To accurately perform a '

reverse flow test on these valves during normal power operation (quarterly) requires entering the x-area, mounting a temporary gauge and monitoring the pressure upstream of the injection valve. This test is impractical because j of the extremely high dose rates in the area couple 6 with the amount of time necassary to determine' valve operability. -

The average dose rate in the X-area during normal resctor operation is  :

approximately 1500 millirem per hour. Two technicians will be required to perform the test. The test will take approximately 30 minutes baring any operational problems (i.e. the possibility of the motor operated valve being

,- stuck open due to the 1000 p'si reactor pressure). The estimated dose to perform this test each quarter of 1.5 ManRem is considered extremely impractict.1.

J To verify closure of the HPCI injection check valve during cold shutdown periods requires isolating the Feedwater and Reactor Water Cleanup systems, draining and venting the respective test volume and leak rate testing the HPCI injection valve. This test is impractical to conduct during cold shutdown because Reactor Water Cleanup flow path and Feedwater being required (means of maintaining reactor coolant inventory) during cold shutdown. Additionally, the added operational and testing burden would delay unit restart.

Alternative Testina: The valves listed in section 2.1 (2(3)-2301-7) will be full-stroke exercised open and closed each reactor refueling.

Additionally, these valves will be partial stroke exercised open during cold shutdowns.

l l

49 l . .

li 4.4.1.4.2 Evaluation -These valves shut to isolate the HPCI system from feedwater pressure and open to allow HPCI injection. It is impractical to full-stroke exercise these' valves open with flow quarterly during power operation since it would require injecting low temperature water into the reactor vessel at a high flow rate, which could cause thermal stresses on the injection nozzles and may result in their premature failure. Full-stroke exercising these valves open with flow during cold shutdowns is impractical since adequate steam pressure is not available to drive the pump turbine to achieve the necessary flow rate.

The licensee's proposal to part-stroke exercise these valves open at cold shutdown and to full-stroke exercise these valves open and closed at refueling outages may give adequate assurance of component operational readiness, however, it is not clear how the part-stroke exercise open will be accomplished. If this is done using the operator lever or attachment on the valve (for both the part- and full-stroke) it is not clear why a full-stroke can not performed each cold shutdown, with the attendant measurement of force or torque as required by IWV-3522.

It is impractical to verify the closure capability of these valves quarterly during power operation or cold shutdown since it requires performance of leak testing on these 14 inch check valves. The reactor would have to be shutdown to perform this quarterly since these valves are exposed to feedwater pressure and feedwater would have to be stopped.

During cold shutdown leak testing this would necessitate extensive draining and realignment of the affected systems, which would likely result in delay-of the return to power operation. Leak testing these valves to verify their closure capability at refueling outages gives adequate assurance of operational readiness of these valves to close and provides a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted from full-stroke exercising these valves closed quarterly or at cold shutdowns provided the licensee full-stroke exercises these valves open each 50

cold shutdown and measures-the force or torque as required by IWV-3522, in addition to full-stroke exercising these valves open and closed each refueling outage.

4.5 Reactor Head Sorav System 4.5.1 Cateaory AC Valves 4.5.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency requirements for the inboard isolation reactor head spray line check valves, 2(3)-205-27, and proposed to full-stroke exercise and leak test these valves each refueling outage, 4.5.1.1.1 Licensee's Basis for Reauestina Relief--These valves are normally closed during both reactor operation and extended shutdown periods. The designated safety position of these valves is closed; however, reactor head spray could be used for injecting into the vessel. Credit for this feature is not taken.

To exercise these valves during operations or cold shutdowns would require injecting approximately 70'F water into the reactor. Injecting cold water into the reactor could cause cracks in the reactor vessel due to thermal shock.

Alternative Testina: These valves will be exercised and leak tested during reactor refueling.

4.5.1.1.2 Evaluation--These head spray injection check valves close to prevent leakage of coolant from the boiler system and are located inside the reactor drywell. It is impractical:to full-stroke exercise these valves open either quarterly during power operation or during cold shutdown since this would require injection of a high flow rate of relatively low

. temperature water into the reactor vessel. This could cause thermal stresses on the injection nozzles and result in their premature failure.

Verification of closure capability is impractical either quarterly or at cold shutdown. The only practical method is leak rate testing which would 51

O,-'

1 require lifting the reactor head and hook-up of leak testing equipment, which could delay'the return to power operation. The licensee's proposal to full-stroke exercise these valves and leak test to verify closure each refueling outage gives adequate assurance of operational readiness and provides a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical, the licensee's proposal provides a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements are imposed, relief should be granted as requested.

4.6 Feedwater System 4.6.1 Cateaory AC Valves 4.6.1.1 Relief Reauest. The licensee has requested _ relief from the Section XI, Paragraph IWV-3521, test frequency requirements for the inboard, 2(3)-0220.58A and -58B, and outboard, 2(3)-0220-62A and -62B, feedwater injection header check valves and proposed to full-stroke exercise these valves closed each refueling outage.

4.6.1.1.1 Licensee's Basis for Reauestina Relief--These valves are normally open and cannot be exercised closed during normal operation because the'feedwater system is required to be operable to maintain reactor coolant inventory. To exercise these valve closed during cold shutdowns would require isolating the feedwater system, deinerting the drywell and backpressurizing the check valves individually to verify closure.

This testing is impractical to perform during cold shutdowns due to the Reactor Water Cleanup path and Feedwater being required (means of maintaining reactor coolant inventory) during cold shutdowns. Additionally, approximately 2,200 gallons of feedwater would need to be drained from the feedwater system headers prior to performing the necessary backflow test.

This added operational and testing burden would invariably delay unit restart.

52

-__- _ - :_:__-=- ___- ____ -___ _ _-___- - - _ _ - - _ _ - _ _ _ - _ _ - - _ - _ _ _ _ -

Alternative Testina: The valves listed in section 2.1 [2(3)-0220-58A,

-588, -62A, and -628) will be exercised closed each reactor refueling.

4.6.1.1.2 Evaluation--These valves are in the feedwater supply lines to the reactor and are normally held open with feed flow. It is impractical to verify the closure capability of these valves during operation since this would isolate one train of feedwater and cause a transient which could result in a reactor scram. It is impractical to test these valves during each cold shutdown because this may require de-inerting containment which is burdensome to the licensee in both time and material cost (i.e., nitrogen required for inerting). Additionally, backpressurizing these valves to verify their leak tight integrity requires extensive test equipment set-up and system reconfiguration and draining would likely result in a' delay in the return to power operation, therefore it would be burdensome to require this testing each cold shutdown.

The' licensee's proposal to verify the full-stroke exercise closed capability of these valves each refueling outage gives adequate assurance of operational readiness and provides a reasonable alternative to the Code requirements.

1 Based on the determination that compliance with the Code requirements is impractical, the licensee's proposal provides a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

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4.6.2 Cateaory C Valves 4.6.2.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency requirements for the HPCI backflow prevention check valves, 2(3) 0220-59, and proposed to full-stroke E

exercise these valves closed each refueling outage, 4.6.2.1.1 Ligy.sce's Basis for Reauestina Relief--To verify l full-stroke exercising of these valves closed requires back pressurizing the 53

+ l valves when the feedwater system is not required. Since feedwater is required for operations, these valves cannot be tested quarterly.

During cold shutdowns, the_ condensate /feedwater system is required to l

be operable in order to maintain reactor water inventory. The normal makeup path to the reactor during cold shutdowns is through the 2(3)-0220-59 check valve and therefore it cannot be isolated for testing.

u, <

Alternative Testina: These check valves will be full-stroke exercised

[ 'during reactor refueling outages when the feedwater system is not required to be operable.

4.6.2.1.2 Evaluatign--This 18 inch check valve is in the '

feedwater supply line to the reactor and is normally held open by feedwater system flow. It is impractical to shut this valve during power operation l since this would isolate one train of feedwater and cause a transient which L could result in a reactor scram. Verification of this valve's closure L capability during cold shutdown is impractical because it requires performance of a leak test. This leak test requires securing normal coolant' j: system makeup, draining the feedwater line, reconfiguring the system, and hook-up and removal'of test equipment, which could result in a delay in the return to power. The licensee's proposal to full-stroke exercise this valve closed each refueling outage gives adequate assurance of operational ,

readiness and provides a reasonable alternative to the Code requirements, i

l Based on the determination that compliance with the Code requirements is impractical, the licensee's proposal provides a reasonable alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

4.7 Isolation Condenser System l

4.7.1 Cateaory C Valves

! 4.7.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency requirements for the l

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4-isolation condenser makeup check valves, 2(3)-1301-11, condensate transfer makeup check valve 2(3)-1301-36, and diesel fire water makeup check valve, 2(3)-4107-501, and proposed to verify the full-stroke capability of these check valves by sample disassembly and inspection as described in the IST program.

4.7.1.1.1 Licensee's Basis for Reauestina Relief--To properly exercise these valves requires running the Diesel Fire pump and discharging the water to the shell side of the isolation condenser. During normal operation, the isolation condenser she11 side contains approximately 22,000 gallons of clean demineralized water. By conducting the required flow test to verify valve operability with the Diesel Fire pump, untreated service water would be introduced to the isclation condenser shell at a rate of 3000 gallons per minute.

The isolation condenser tubes are the primary boundary between the reactor vessel water and outside secondary containment. Service water contains chlorides, sulfates and minerals which would deposit on the tubes and cause pitting and eventual tube failure.

To drain, clean and refill the isolation condenser with clean demineralized water every 3 months after verifying valve operability by flow testing is not possible since the isolation condenser is required for normal reactor operations and the time to drain and fill the condenser may possibly exceed the Limiting Condition for Operation.

Alternative Testina: The valves listed in section 2.1 (2(3)-1301-11, 2(3)-1301-36, and 2(3)-4107-501] will be disassembled and inspected to verify valve operability _in accordance with the sampling technique discussed in DAIM-V22, 4.7.1.1.2 Evaluation--These check valves open to provide cooling flow to the isolation condenser. It is impractical to part- or full-stroke exercise these check valves open with flow quarterly during power operation, during cold shutdown, or during refueling outages since this would result in the introduction of chemically contaminated firewater into the shell side of l

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and lead to their premature failure. Extensive system modification would be necessary to allow full-stroke exercising these valves with flow, which would be costly and burdensome for the licensee.

Disassembly, inspection and manual full-stroke of the valve disk can adequately ascertain a check valve's internal condition. However, the NRC staff considers this to be a maintenance procedure.with inherent risks, which should be used as a substitute for testing only when no testing method is feasible, and which should always be followed by a part-stroke exercise with flow. Disassembly and inspection should be performed under a plant maintenance program at a frequency commensurate with the check valve type and service. The licensee's proposed sample disassembly and inspection program should adequately determine valve condition and provides a reasonable alternative to the Code requirements. If the licensee feels that an extended inspection interval is warranted, this should be justified in a resubmittal, i

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted as requested.

4.8 Standby Liouid Control System 4.8.1 Cateaory AC Valves 4.8.1.1 Relief Reauest. The licensee has requested relief from the p Section XI, Paragraph IWV-3521, test frequency requirements far the standby l liquid control (SBLC) injection check valves, 2(3)-1101-15 and -16, and proposed to full-stroke exercise these valves open with flow and verify leak tight integrity by leak testing these valves each refueling outage.

4.8.1.1 Licensee's Basis for Reauestina Relief--Exercising these L ' valves requires firing the squib valves and injecting demineralized water into the reactor vessel. Injecting ambient water into the reactor vessel 56

J during operations is undesirable because the SBLC system would be inoperative during this test due to the isolation of the sodium pentaborate solution (neutronpoison). In addition to SBLC being inoperative and placing the plant in a seven day Technical Specifications Limiting Condition ofOperation(LCO),injectingcoldwaterintothereactorwouldeventually fatigue and crack the injection nozzles due to the induced thermal shock.

In addition to the nozzle cracking concerns, a cold water transient in the vessel would cause a reactor trip.

Because sodium pentaborate is a neutron poison, it is imperative that there be a physical separation between the poison and the primary system.

To attempt a full flow test during a cold shutdown period would require a-thorough system flushing and either removal or firing of one explosive valve. .is work is beyond the scope of a normal cold shutdown period.

Alternative Testina: These valves will be exercised during reactor refueling outages. This will be done in conjunction with the firing ~of one explosive squib valve and injecting demineralized water into the reactor vessel at rated system flow. These valves are also leak tested during reactor refueling outages.

4.8.1.1.2 Evaluation--These check valves are in the common SBLC injection line to the nuclear boiler, downstream from the explosively actuated squib valves. It is impractical to full-stroke exercise these valves open with flow, either quarterly during operations or at cold i shutdown. Initiation of system flow requires the firing of at least one squib valve, which destroys the valve. Further, the system contains highly borated water that would be introduced into the nuclear boiler system and cause a reactor shutdown during power operation. Extensive flushing must be performed on the system and all traces of the boron solution must be removed prior to initiating. flow for exercising these valves. Performance of this testing during cold shutdowns would be burdensome to the licensee since this testing could result in an extension of the cold shutdown.

The licensee's proposal to full-stroke exercise these valves open each refueling outage by firing one of the squib valves and injecting I

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.y demineralized water into the reactor coolant system provides' an acceptable level of quality and safety and a reasonable alternative to the Code requirements. The only method available to verify the closure capability of these valves is leak testing. The licensee's proposal to verify the closure capability of these valves via leak testing each refueling outage provides a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical, the licensee's proposed testing provides a reasonable #

alternative to the Code requirements, and considering the burden on the licensee if the Code requirements were imposed, relief should be granted as requested, j 4.9 Core Sorav Systm 4.9.1 Cateoory C Valves 4.9.1.1 Relief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency and test method requirements for the core spray keep fill check valves, 2(3)-1402-34Aand-348,and l proposed.to yerify the full-stroke capability of these valves by performing

{ sample disassembly and inspection each refueling outage as described in L

their IST program.

4.9.1.1.1 Licensee's Basis for Reauestina Relief--Exercising closed the core spray keep fill check valves quarterly is not possible since the-downstream valve (1402-36) is also a check valve (two check valves in series) and can not be back pressurized during normal core spray pump +

L testing.

l Valves 2(3)-1402-34A and B can not be verified closed independently of the 2(3)-1402-36A and B by any direct or indirect method during normal operations or cold shutdown periods because test connections between the valves do not exist. Valves 2(3)-1402-36A and B are verified closed each quarter by closing the valve handwheels, i

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Alternative Testina: The valves listed in section 2.1 [2(3) 1402-34A and -34B) will be disassembled and inspected on a refueling outage basis to verify valve operability in accordance with the sampling technique discussed in DAIM V22, 4.9.1.1.2 Evaluation--Valves 2(3)-1402-34A and -34B are in series with stop check valves, 2(3)-1402 36A and -368, and function in the closed position to prevent diversion of core spray flow during injection. It is t -impractical to verify valves 2(3)-1402 34A and -34B closed either quarterly or during cold shutdowns since they have no provision for external verification of valve position (i.e., position indicators, pipe taps).

Installation of instrumentation to verify valve position would involve system redesign and be burdensome to the licensee. However, the licensee can verify that the downstream in-line stop check valves operate to the closed position using the handwheel quarterly, which gives greater assurance that the pair will perform its safety function.

It is impractical to test valves 2(3)-1402-34A and -34B in accordance with the Code requirements. The licensee has proposed to perform sample disassembly and inspection on these valves during refueling outages to verify their operational readiness, however, this method should be used only as a last resort, where no other method can reasonably be utilized. A practical method that will adequately verify the reverse closure capability of these series check valves (2(3)-1402-34A, -3.!B, -36A, and -36B) would be leak testing the pair at least once each refueling outage. If excessive leakage is noted then both valves should be repaired or replaced as necessary. This testing in addition to quarterly exercising of valves 2(3)-1402-36A and -36B gives reasonable assurance of component operational readiness-and provides a reasonable alternative to the Code requirements.

Based on the determination that compliance with the Code requirements is impractical and considering the licensee's proposal and the burden on the licensee if the code requirements were imposed, relief should be granted provided the pair of series check valves is leak tested at least each refueling outage. If excessive leakage is noted, both valves should be repaired or replaced as necessary.

59

4.10 Low Pressure Coolant- Iniection System 4.10.1 Cateaory C Valves

.4.10.1.1 Relief Reauest. The licensee has requested relief from the Section XI Paragraph IWV-3521, test frequency and test method requirements-for the low pressure coolant injection system (LPCI) keep fill check valves, 2(3)-1501-67A and -678, and proposed to verify the full-stroke capability of I these valves by performing sample disassembly and inspection each refueling outage as described in their IST program.

4.10.1.1.1 Licensee's Basis for Reauestina Relief--Exercising closed the LPCI keep fill check valves quarterly is not possible since the 4 downstream valve (1501-66) is also a check valve (two check valves in series) and can not be back pressurized during normal LPCI pump testing.

Valves 2(3)-1501-67A and B can not be verified closed independently of the 2(3)-1501-66A and B by any direct or indirect method during normal operations or cold shutdown periods because the connections between the valves do not exist.

Valves 2(3)-1501-66f. and B are verified closed each quarter by closing the valve handwheels.

Alternative Testina: The valves listed in section 2.1 (2(3)-1501-67A and -67B] will be disassembled and inspected on a refueling outage basis to verify valve operability in accordance with the sampling technique discussed in DAIM-V22.

4.10.1.1.2 Evaluation--Valves 2(3)-1501-67A and -678 are in series with stop check valves 2(3)-1501-66A and -66B and function to prevent diversion of LPCI flow during injection. It is impractical to verify valves 2(3)-1501-67A and -678 closed either quarterly or during cold shutdowns since they have no provision for external verification of valve position (i.e.,positionindicators,pipetaps). Installation of instrumentation to 60

verify valve position would involve system redesign and be burdensome to the licensee. However, the licensee can verify that the downstream in-line stop check valves operate to the closed position using the handwheel quarterly, which gives greater assurance that the pair will perform its safety function.

It is impractical to test valves 2(3)-1501-67Aand-67Binaccordance with the Code requirements. The licensee has proposed to perform sample disassembly and inspection on these valves during refueling outages to verify their operational readiness, however, this method should be used only as a last resort, where no other method can reasonably be utilized. A practical method that will adequately verify the reverse closure capability.

of these series check valves (2(3)-1501-67A, -678, -66A, and -66B) would be leak testing the pair at least once each refueling outage. If excessive.

leakage is noted then both valves should be repaired or replaced as necessary.- This testing in addition to quarterly exercising of-valve 2(3)-1402-66A and -66B gives reasonable assurance of component operational readiness and provides a reasonable alternative to the Code requirements. -

Based on the determination that compliance with the Code requirements is. impractical and considering the licensee's proposal and the burden on the licensee if the Code requirements were imposed, relief should be granted provided the pair of series check valves is leak tested at least each refueling outage. If excessive leakage is noted, both valves should be repaired or replaced as necessary.

4.11 TIP Nitroaen Purae Systs - 4.11.1 Cateaory AC Valves 4.11.1.1 Eg_ lief Reauest. The licensee has requested relief from the Section XI, Paragraph IWV-3521, test frequency and requirements for the-traversing in-core probe (TIP) nitrogen purge containment isolation check valves, 2(3)-4799-514, and proposed to verify the full-stroke capability of these valves during cold shutdowns when containment is de-inerted and during refueling outages.

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4.11.1.1.1 Licensee's Basis for Reauestina Relief--These valves are normally open and are required to close for containment isolation.

These check vlaves are required to be open to maintain a constant nitrogen l purge. Exercising these valves requires disconnecting the line downstream l

. of the valves and applying external pressure to back seat the valves. To '

secure the TIP system during operation in order to exercise these valves is not considered practical, and would result in violating primary containment.

1 1

Alternative Testina: Therefore, these valves'will be exercised during cold shutdowns when the drywell is de-inerted.

4.11.1.1.2 Evaluation--These TIP purge valves are located inside the primary containment which is inerted with nitrogen during power operation and during some cold shutdowns. Exercising these valves requires entry into containment. It is impractical to perform this testing quarterly during power operation.or during cold shutdowns when containment is inerted because of the personnel safety hazard posed by the oxygen deficient '

atmosphere. Purging and re-inerting containment is costly and could result '

in delay of plant startup from cold shutdown, which would be burdensome to the' licensee. Exercising these valves during cold shutdowns when '

containment is de-inerted and at each refueling' outage should give adequate assurance of operational readiness and provides a reasonable- alternative to.

t;'e Code requirements.

Based on the determination that compliance with the Code requirements is impractical and considering that the licensee's proposal provides a reasonable alternative to the Code requirements, relief should be granted as requested.

62

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e APPENDIX A VALVES TESTED DURING COLD' SHUTDOWNS' A-1

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APPENDIX A l VALVES TESTED DURING COLD SHUTDOWNS j The following are Category A, B, and 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 paragraph 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 l licensee that testing these valves during power operation is not practical ,

due to-the valve type, location, or system design. These valves should not be full-stroke exercised during power operation. These valves are listed below and grouped according to the system in which they are located.

1. REACTOR RECIRCULATION SYSTEM l 1.1 Cateaory B Valves i

The recirculation pump discharge valves, 2(3)-0202-5Aand0202-58, cannot be full-stroke exercised quarterly during power operation. For Unit 2,

_ exercising these valves would require a load drop (of approximately 400

. megawatts) to a minimum recirculation pump speed of 28%. For Unit ?,

exercising these valves would require a load drop to a minimum recirculation

_ pump speed of 28% and insertion of control rods to achieve less than 80% flow l control line-(FCL). The closure logic for these valves would result in the

l. recirculation pump trip and would place the plant in an unwanted system / power transient, as well as in Technical Specifications Limiting Condition for Operation (LCO). The potential of operating in the prohibited region of the power flow map (above 80% flow control line, below 39% core flow) exists when p one (1) recirculation pump is shut down. The low flow /high power region of the operating map typically exhibits less margin to stability than other regions. Instabilities result in LPRM and APRM Oscillations significantly greater than-normal noise levels. These valves will be full-stroke exercised during cold shutdowns and refueling outages.

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2. CORE SPRAY SYSTEM 2.1 Cateoory A/C Valves The core spray injection check valves, 2(3)-1402-PA and 1402-98, cannot be full-stroke exercised quarterly during power operation because the high '

differential pressure across the seats of these core sp ay (CS) valves prohibits the stroking them. Additionally, the reactor aressure is too high for the system and injection into the reactor is not posiible. These valves will be exercised during cold shutdowns and refueling outages.

3. LOW PRESSURE COOLANT INJECTION SYSTEM i

3.1 Cateaory A/C Valves The low pressure coolant injection (LPCI) check valves, 2(3) 1501 25A L and 1501-25B, cannot be full-stroke exercised quarterly during power -

operation because the high differential pressure across the seats of the LPCI valves prohibits the stroking them. Additionally the reactor pressure is too l: high for the system and injection into the reactor is not possible. These valves will be exercised during cold shutdowns and refueling outages.

3.2 Cateaory B Valves The LPCI crosstie valves, 2(3)-1501-32A and 1501-32B, cannot be full-stroke exercised quarterly during power operation. These valves are L normally open to allow all four of the LPCI pumps to inject through one set of injection valves. This prevents pump damage as well as allowing all four l pumps to inject. Since these valves do not auto-open on a LPCI initiation, L closing any of the crosstie valves will render both LPCI Loop A and Loop B

l. inoperable. This is not considered to be a safe practice and would require Dresden to enter a Limiting Condition of Operation with the LPCI system inoperable. These valves will be full-stroke exercised during cold shutdowns and refueling outages.

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4. INSTRUMENT AIR SYSTEM 1 .

4.1 Cateaory A Valves The instrument ' air header containment isolation valves, 2(3)-4722,cantM be full-stroke exercised quarterly during power operation because these i valves provide ,the containment isolation function for the instrument air system which supplies various fail-safe valves, including the main steam isolation valves.(MSIV's). Exercising and fail-safe testing of the 2(3)-4722 valves during reactor operation could cause the instrument air system to bleed down should the 2(3)-4722 fail closed. Without air to hold open the MSIV's, the MSIV's would be exercised to their fail-safe position (closed).. ,

Closure of the MSIV's during reactor operation would cause transient conditions which would result in a reactor scram and loss of the reactor's j primary heat sink. These valves will be exercised and fail-safe tested

'during cold shutdowns and refueling outages.

5. CONTAINMENT AIR MONITOR SYSTEM 5.1 Cateaory A/,C Valves The containment air monitor system' containment isolation-check valves,.

2(3)-2499-28A and 2(3)-24998, are normally open and are required to close for containment isolation. They are required to be open for proper operation of the containment atmosphere monitor system. These valves cannot be

'~

full-stroke exercised to the closed position quarterly during reactor operation because verifying closure would require securing the system, and

' disconnecting the line and air back pressurizing which would violate primary l containment during operation. Verification of closure will be performed by  :

leak testing during cold shutdowns and refueling outages.  !

6. CONTAINMENT lSOLATION SYSTEM 1

l 6.1 Cateaory A Valves I L

The reactor building containment isolation valves, 2(3)-3702,3703,

, and 3706, cannot be full-stroke exercised to the closed position quarterly A5

c during reactor operation. These valves are normally open and are required to close for containment isolation. They provide primary containment isolation for the reactor building cooling water system. To exercise ti.ese valves to-the closed position vould require both recirculation pumps to be out of service because-the recirculation pumps require seal purge fer operation.

These valves will be exercised during cold shutdowns and refueling outages.

6.2 Cateaory A/C Valves Primary containment isolation valves, 2(3)-2599-23A,2599-23B,259924A, and 2599-248, cannot be full-stroke exercised to the closed position quarterly during reactor operation. These valves are normally closed and'are required to close' for containment isolation. They are also required to open for proper operation of the atmospheric containment atmosphere dilution system. These valves are exercised open every quarter; however, to verify closure would require securing the atmospheric containment atmosphere dilution system, disconnecting the piping and at back pressurizing. This testing is impractical to perform during power operation due to the amount of piping needed to be disconnecteri and the time constraints of performing the test. The closure capability ;f these valves will be verified during cold shutdowns and refueling outages.

7. MAIN STEAM SYSTEM 7.1 Cateaory A Valves The following main steam isolation valds cannot be full-stroke exercised quarterly during power operation. These valves are normally open and are required to close for containment isolation. They provide primary, containment isolation for the main steam system. These valves are air operated open and air to close with spring assist. To completely fail-safe exercise these valves to the closed position, the air lines to the valves must be disconnected. Thus, with the loss of air, the fail-safe mechanism (springs) would be demonstrated. Tha resultant exercising of the MSIV's could place the plant in an unsafe mode of operation causing transient A-6

'l ... l 0

conditions which would result in a reactor scram. These valves will be full stroke exercised during cold shutdowns and refueling outages.  ;

' 2(3) 0203-1A 2(3) 0203 1B 2(3) 0203 1C 2(3) 0203 10 ,

2(3)-02032A 2(3)0203-28 2(3)02032C 2(3) 0203 20 1

8. CONTROL ROD DRI'/E SYSTEM 8.1 Cateoory C Valves  !

i The control rod drive (CRO) accumulator backflow check valves to the i charging water line, 2(3) 0305 115, cannot be exercised quarterly during power operation. In order to verify '.losure of these valves, the control rod drive water pump would need to be secured. In doing this, the seal purge water flow to the recirculation pump seals and cooling water to the control ,

rod drive seals would be stopped and possible damage to these seals would result. Therefore, these valves will be exercised during cold shutdowns when

• he charging water he der can be depressurized. Monitoring individual accumula tor pressure and alarms will be performed to verify that the check '

valves have closed on reversed flow. These valves will be full stroke exercised during cold shutdowns and refueling outages.

L

9. HIGH PRESSURE COOLANT INJECTION SYSTEM ,

9.1 Cateoory AC Valves High pressure coolant injection turbine steam exhaust check valves, ,

2(3) 2301-34, -45,-71, and 74, have a safety function in the open direction for proper operation of the HPCI system and they also have a safety function in the closed direction for primary contairient isolation. These valves are considered to be open as demonstrated during HPCI surveillance tests. To verify closure, as is required for containment isolation, these valves will be tested during the leakage test requirements of Category A testing, these valves are leak tested per Appendix J requirements every refueling outage.

l Verification that these valves are closed is not readily possible during normal operation. These valves open when operating the HPCI turbine.

Verificction of closure would require manual exercising of the stop checks A7

4- .

which would require securing the HPCI Turbine. This is not considered to be a safe practice and would require Dresden to enter a Limiting Condition of Operation with the HPCI system inoperable. These valves will be full stroke exercised during cold shutdewns and refueling outages.

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APPENDIX B P&lD LIST i

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7-APPENDIX B PalD LIST The P&lDs listed below were used during the course of this review, SYSTEM DRAWING NO.

Nuclear Boiler and Reactor Recirculating System M26 SH2 Nuclear Boiler and Reactor Recirculating System M26 SH1 Main Steam System 151 12-1 Main : team System M12 SH2 Reactor Feed System M 14 Control Rod Hydraulic System M 34 Shutdown Reactor Cooling System M 32 Standby Liquid Control System M 33 Reactor Water Cleanup System M 30 Isolation Condenser System M 28 Core Spray System M-27 Low Pressure Coolant Injection System - M 29 SH1 Low Pressure Coolant injection System M 29 Reactor Building Equipment Drains System M 39 High Pressure Coolant Injection System M 51 Containment Atmosphere Monitor System M-706 Containment Atmosphere Dilution System M 707 Reactor Building Cooling Water System M 20 Service Water System M-22 Service Water System M 355 Control Room HVAC System M 3121 Standby Gas Treatment System M-49 Pressure Suppression System M 25 Instrument Air System M-37 SH2 Reactor Building Ventilation System M 269 High Radiation Sampling System M 1234 B3

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APPENDIX C IST PROGRAM ANOMALIES IDENTIf!ED DURING THE REVIEW l

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APPENDIX C IST PROGRAM ANOMAL.!ES FOUND DURING THE REVIEW Inconsistencies and omissions in the licensee's program noted duiing the course of this review are sumarized below. The licensee should resolve these items in accordance with the evaluations, conclusions, and guidelines presented in this report.

1. Pump relief request PR-1 (see Section 3.1.1 of this report) requests <

relief from measurement of vibration displacement per IWP 4500 and proposed to measure vibration velocity and evaluate per the program '

presented in their program, however, their proposal differs from the program in OH 6. The licensee should utilize all the criteria regarding vibration testing contained in ASME/ ANSI OMa 1988, Part 6.

2. Pump relief request PR 7 (see Section 3.5.1 of this report) requests l to assign limiting values of vibration velocity for the high pressure coolant injection pumps based on multiples of reference values, which have been high historically. Absolute vibration velocity limits should be assigned to ensure these pumps are declared inoperable and corrective action is called for prior to failure.

3. Valve relief request VR-2 (see Section 4.3.3.1 of this report) requests relief from the test sample expansion requirement for the main steam safety valves if a tested valve fails "as found" setpoint testing. However, performance of this test is not considered impractical or excessively burdensome. Further, it may be non conservative not to perform the "as-found" test. If a tested valve fails the "as found" setpoint test the licensee should perforrr safety-relief valve sample expansion as required by the Code.

4.. Valve relief request VR-5 (see Section 4.1.1.1 of this report) l- requests to utilize the valve stroke time testing requirements of IWV 3413 from a newer edition of Section XI than the edition in use for their IST program. The licensee should stroke time all i power operated valves in their IST program to at least the nearest

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5. Valve relief request DAIN VI (see Section 4.1.1.2 of this report) addresses power-operated valves with stroke times greater than 2 s. i and proposes to establish stroke time baseline values and assign alert limits based on these values for these valves. Also maximum valve i full-stroke times will be assigned based on Technical Specifications or other documents. The licensee should assign limiting values of l

full-stroke time for all power operated valves in their IST program in {

accordance with NRC Generic letter No. 89 04, Attachment 1, Position 5.

6. Valve relief request VR 6 (see Section 4.1.2.1 of this report) l requests to test primary containment isolation valves to the criteria of 10 CFR 50, Appendix J, and plant Technical Specifications. The

-licensee should test these valves in accordance with NRC Generic Letter No. 89 04, Attachment 1, Position 10. ,

7. Valve relief request VR 8 (see Section 4.2.1.1 of this report) requests to exercise the control rod drive (CRD) alternate rod insertion / anticipated transient without scram air header bleed valves each cold shutdown without stroke timing. Appropriate valve stroke time acceptance criteria should be developed and valve operation should be verifiec' within this acceptance criteria.

8. Valve relief request VR 9 (see Section 4.2.1.2 of this report) requests to exercise the CRD backup scram and scram dump valves each cold shutdown without stroke timing. Appropriate valve stroke time acceptance criteria should be developed and valve operation should be i verified within this acceptance criteria.

9. Valve relief request VR-10 (see Section 4.3.2.3 of this report) requests relief from the requirement to perform 'as found" setpoint testing of the Target Rock safety relief valves. However, performance of this test is not considered impractical or excessively burdensome to the licensee. Also, the proposed testing may not monitor l

degradation affecting the valve's setpoint mechanism and does not give adequate assurance of operational readiness and provide a reasonable L

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e alternative to the Code requirements. Therefore, the licensee should perform *as-found" setpoint testing of these valves in accordance with the Code requirements.

10. The NRC staff has detemined that the spent fuel pool cooling system performs a safety-related function and that the system pumps and l' valves necessary to fulfill this function should be included in the IST program and be tested to the Code requirements.

11. Valve relief request VR 13 (see Section 4.9.1.1 of this report) requests to verify closure capability of the core spray system keep fill check valves by disassembly and inspection. Relief is granted provided the licensee leak tests the valve series at least each refueling outage.

12. Valve relief request VR 14 (see Section 4.10.1.1 of this report) requests to verify closure capability of the low pressure coolant injection system keep fill check valves by disassembly and inspection. Relief is granted provided the licensee leak tests the valve series at least each refueling outage.

j 13. Valve relief request YR 18 (see Section 4.4.1.2 of this report) requests to verify check valve closure capability of the HPCI system keep fill check valves by disassembly and inspection. Relief is granted provided the licensee leak tests the valve series at least each refueling outage.

14. Valve relief request VR 19 (see Section 4.4.1.3 of this report) requests to verify open and closure capability of the HPCI turbine exhaust vacuum breakers by disassembly and inspection. Relief is granted provided the licensee exercises these valves per the proposal in the IST program or functionally tests the set of valves open and closed at least each refueling outage.

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15. Valve relief request VR-22 (see Section 4.4.1.4 of this report) requests to part-stroke exercise the HPCI injection check valves, 2(3)-2301-7, open each cold shutdown and full-stroke exercise them open and closed each refueling outage. The licensee should full-stroke exercise these valves open each cold shutdown and measure the force or torque as required by IW-3522. The licensee should also full-stroke exercise these valves open and closed each refueling outage.

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