ML20128C172

Safety Evaluation Accepting First 10-yr Interval Inservice Testing Program for Pumps & Valves

ML20128C172
Person / Time
Site:	Comanche Peak
Issue date:	01/29/1993
From:	Office of Nuclear Reactor Regulation
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ML20128C143	List: ML20128C139 ML20128C172
References
NUDOCS 9302030332
Download: ML20128C172 (17)

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[CCtey UNITED STATES

!" f n NUCLEAR REGULATORY COMMISSION O WASHINoTON, D. C. 20$55

\.....)$ SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE FIRST TEN-YEAR INTERVAL INSERVICE TESTING PROGRAM PLAN TEXAS UTILITIES ELECTRIC COMPANY COMANCHE PEAX STEAM ELECTRIC STATION. UNIT 1 DOCKET NO. 50-445 INTRODUCTION The Code of Federal Regulations, 10 CFR 50.55a, requires that inservice testing (IST) of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in cccordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable addenda, except where relief has been granted or proposed alternatives have been authorized by the Commission pursuant to 50.55a (f)(5)(iii), (z)(3)(1), or (a)(3)(ii). In requesting relief or proposing an alternative, the licensee must demonstrate that: (1) conformance is impractical for its facility; (2) the proposed alternative provides an 4 acceptable level of quality and safety; or (3) complianco would result in a hardship or unusual difficulty without a compensating increase in the level of '

quality and safety. NRC guidance contained in Generic letter

" Guidance on Developing Acceptable Inservice Testing Programs,"(GL) provided 89-04, alternatives to the Code requirements determined to be acceptable to the staff and .*uthorized the use of the alternatives in Positions 1, 2, 6, 7, 9, and 10 pron ded the licensee follows the guidance delineated in the applicable position. When an alternative is >roposed which is in accordance with GL 89-04 guidance and is documented in tie IST program, no further evaluation is required; however, implementation of the alternative is subject to NRC inspection.

Section 50.55a of Title 10 of the Code of Federal Regulations authorizes the Commission to grant relief from ASME Code requirements or to approve proposed alternatives upon making the necessary findings. The NRC staff's findings with respect to granting or not granting the relief requested or authorizing the aroposed alternative as part of the licensee's IST program are contained in t11s Safety Evaluation (SE).

This SE concerns relief requests and' supporting information that were submitted by letters dated October 3, 1991, and July 2, 1992, for the Comanche Peak Steam Electric Station, Units 1 and 2, IST program. The IST program included in the July 2,1992, submittal suparsedes all previous revisions of the program and incorporates the information included in the October 3, 1991, submittal related to Revision 4 of the Unit 1 IST program. Therefore, the evaluations below relate to Revision 0 dated July 2,1992, of the new IST program and all relief request numbers correspond to the Revision 0 designation. Additionally, by letter dated January 18, 1993, the licensee augmented the proposed IST for certain chemical and volume control system valves.

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EEBAL The Comanche Peak Steam Electric Station (CPSES) IST program includes information on the test interval for implementing the inservice testing and specifies the Code edition used in developing the program.

Test Intervals The IST program relief requests addressed in this SE apply to the first ten-year interval for both units. Section 1.3 of the Comanche Peak IST Program indicates that both units "will be subject to the same inservice testing requirements as regards Code edition and schedule for future periodic updates pending NRC staff approval." The implementation of Revision 0 is due to be complete for Unit 1 before returning to power from the third refueling outage (IRF03). The implementation for Unit 2 is to begin upon issuance of the license for comercial operation. The licensee proposes to use the comercial operation date of Unit 2 for establishing the 120-month interval for both units. The staff has determined that for facilities which include two similar units, it is advantageous to im)1ement an-inservice testing program consistent between units by using 11e same Code edition for developing the program and for scheduling ten-year updates. Section 50.55a(f)(4)(iv) allows the use of later editions of the Code subject to the limitat90ns and modifications in 50.55a(b) and subject to Comission a) proval. The licensee did not request an exemption from the regulations whici requires an update to the later edition of the code. If the licensee does not intend to update the Unit 1 IST program at 120-months after comercial operation, an exemption from the regulation is required to be submitted prior to 120 months from the date of Unit I comercial operation.

Cnde Edition Revision 0 was developed utilizing the 1989 Edition of ASME Section XI which was approved by rulemaking effective September 8,1992,- to 10 CFR 50.55a (reference 5/ FR 34666, August 6,1992). The licensee requested NRC approval (iv) to use this edition uf the Code. This SE provides the per $50.55a(f)(4)l requisite ap)rova to meet the requirements set forth in the 1989 Edition subject to t se limitations and modifications listed in i 50.55a(h containment isolation valve leakage testing, with the scope of the) related to inservice testing program as defined by $50.55a. The 1989 Edition of ASME Section XI references Operations and Maintenance (OH) Standards, Part 6 and Part 10, 1988 Addenda, for the rules of inservice testing of pumps and valves.

Additionally, when using OH-10 for inservice testing requirements, OH-1-1987 must be used for safety and relief valve testing rather than OH-1-1981. The scope of the safety and relief valves includes any valves in cortain Class 1, 2, or 3 systems which provide overpressure protection, as first stipulated in the 1986 Edition of ASME Section XI. Revision 0 incorporates these 1 requirements.

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t 13;MP INSERVICE TESTING RELIEF RE0VEH The IST program includes a pump table which lists all pumps subjact to inservice testing and denotes design features and applicable testing requirements. As discussed above, the pump inservice testing program was develo)ed using the 1988 Addenda of OM-6. The licensee has also incorporated the vi) ration severity chart which was inadvertently omitted frnm the 1988 Addenda and issued in the 1989 Addenda to OH-6. One pump relief request to the OH-6 requirements was identified in Revision 0.

Eglief Reouest P-1 The licensee has requested relief for the diesel generator fuel oil transfer pumps, four per unit, from the requirements of OH-6, 6.1, " Acceptance Criteria," and Table 3b, " Ranges for Test Parameters."

Licensee's Basis for Reliti The licensee stated "Unlike earlier editions of ASME Section XI, OM Part 6 emphasizes the use of bearing vibration measurements as the primary indicator of pump degradation and places less emphasis on hydraulic measurements.

Further, OM Part 6 introduces the classification of pumps by type. According toReferences1and2[1. John Zudans, " Introduction to ASME/ ANSI OMa-1988, Part 6: Inservice Testlng of Pumps in Light-Water Reactor Power Plants and Technical Differences Between Part 6 and ASME Section XI, Subsection IWP," in Proceedings of the Symposium on Inservice Testing of Pumps and Valves, NUREG/CP-Olll at 25-58 (1989). 2. Lawrence Sage, " Introduction to ASME/ ANSI OMa-1988, Part 6: Basis of the New Vibration Measurement criteria and Requirements of Part 6, Id at 59-74.1, pump classification is introduced in recognition of the fact that the quailty of vibration measurements varies among pump types. By classifying pumps, different test requirements and acceptance criteria can be specified depending on type. For example, vertical line shaft pump bearings are generally inaccessible for vibration monitoring.

So to comnensate, OH Part 6 imposes more stringent hydraulic acceptance criteria for these pum)s and additionally requires that vibration monitoring be done on the driver ) earings.

Another pump type which incurs a penalty in hydraulic acceptance criteria in OM Part 6 is reciprocating positive displacement pumps. Reciprocating pumps are characterized by pulsating flow and high oscillating inertia forces due to the back and forth motion of the pressu.e producing members. Therefore, diagnosing the mechanical condition of reciprocating pumps using vibration measurements is somewhat difficult and to compensate, ON Part 6 specifies a reduced range of hydraulic acceptance criteria for these pumps.

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4 Throughout OM Part 6, the terms " position displacement pump" and

" reciprocating sump" are used interchangeably. However, from Reference 2 it is clear that tie pump type being addressed is the reciprocating variety of positive displacement pumps. Unfortunately. OM Part 6 ignores the other variety of positive displacement pumps, rotary positive displacement pumps.

The Fuel Oil Transfer Pumps are rotary positive displacement pumps which du not share the inherent difficulties and limitations of bearing vibration diagnostics which reciprocating pumps experience. On the contrary, these low inertia, untimed multiplesrotor screw pumps are characterized by low mechanical vibration, pulsation-free axial flow and bearing loadings which do not vary through the pumping cycle. The bearings are quite accessitle as the pump bores thenselves effectively form continuous hydrodynamic fluid film bearings along the entire length of the rotors. The machanical condition of screw pumps can be well understood through vibration monitoring.

Reference 2 discusses the pump classification methodology used by the O&M Task Group on Vibration Monitoring in prepad ng OM Part 6. That task group drew heavily on guidance from Reference 3 [3. International Standards Organization Standard, ' Mechanical Vibration of Machint.s with Operating Speeds from 10 to 200 Revolutions per Second - Basis for Specifying Evaluation Standards," 150 2372, 1st ed. 1974-11-01.) in classifying pump types. Of the six classes of pumps recognized in the ISO standerd, the group determined that most pumps in nuclear power slant applications fell into one of two 150 classes: Class III or Class V. Tae primary difference between these classes is that Class III comprises rotating machines where Class V comprises reciprocating machines.

These ISO classifications were translated into OM Part 6 as two major pump types: centrifugal and reciprocating positive displacement. (Note that vertical line shaft pumps are a special case of centrifugal pumps.) The subsect screw type pumps were not specifically considered for classification

, by the task gruup. Nonetheless, they are inadvertently classified with I

reciprocating pumps in ON Part 6 due to the use of the general term " positive displacement." The fuel Oil Transfer Pumps are most closely 150 Class Ill pumps and should therefore be subject to the applicable requirements and l criteria for centrifugal pumps in OM Part 6."

i Alternative Testina The licensee proposed *For the purpose of determining the Acceptable Range, Alert Range, and Required Action Range for Fuel Oil Transfer Pump flow rate (Q), the ranges specified in OM Part 6, Table 3b for centrifugal pump flow rate shall be used.

For the purpose of determining the Acceptable Range, Alert Range and Required Action Range for Fuel Oil Transfer Pump discharge pressure (P), the rangas specified in ON Part 6 Table 3b for centrifugal pump differential pressure shall be used.

For the purpose of determining the Acceptable Range, Alert Range and Required Action Range for Fuel Oil Transfer Pump Vibration (V),-the ranges specified in OM Part 6, Table 3a for centrifugal pump vibration shall be used.

f For the purpose of making fuel Oil Transfer Pump vibration measurementr, the requirements of OM Part 6, para. 4.6.4(a) shall apply."

[1Alttd10D International Standard 150 2372 addresses vibration for rotating eculpment as discussed in the licensee's bhsis for relief. Annex A of the stantard provides guidance for classifying machinery and assigning ranges of " quality judgment" for each of these classes that relate to vibration severity levels.

Class !!! is appropriate for "(1)arge prime movers and other large machines with rotating masses mounted on rigid and heavy foundations which are relatively stiff in the direction of vibration measurement." Class V is appropriate for "(m]achines and mechanical drive systems with unbalanceable inertia efforts (due to reciprocating parts), mounted on foundations which are relatively stiff in the direction of vibration measurement." In a phone conference October 7,1992, the licensee verified that the diesel fuel oil transfer pumps are rigidly mounted on a "relatively stiff" foundation. This assessment is supported by information that rotary screw pumps with right- and left-hand helices have a balanced load, and that for double-screw pumis, flow is practically continuous. (See Theodore Baumeister and 1.tonel S Mar (s.

Standard Handbook for Mechanical Engineers, 7th ed. at 14-16,17 1967)).

Additionally, the licensee notes that the rotation of the pumps oes not create an unbalanced inertia force as would be created by a reciprocating pump. Therefore, these pumps are more similar to centrifugal pumps in the context of OH-6.

By considering the pumps subject to the limits for centrifugal pumps rather than positive displacement pumps for OH-6 acceptance criteria, this effectively eliminates an alert range and changes the hydraulic required action limit for flow from .93 times the reference to .90 times the reference l value. The vibration limits will not effectively changs other than by classifying these as centrifugal pumps, an absolute alert limit and required l

action limit are required in addition to the limits applied as multipliers of l

reference values. Depending on the current reference values for vibration,

! derived from initial tests, the licensee's alternative is at least as l conservative as the limits for reciprocating pumps. Therefore, the licensee -

l has determined that classifying the fuel oil transfer pumps as centrifugal pumps is conservativa. Based on this, the staff has determined that the alternative provides an acceptable level of quality and safety based on the l type of pumps and the service application.

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[onclusion The proposal to apply the limits of OH-6 for centrifugal pumps rather than positive displacement pumps for the rotary diesel fuel oil transfer pumps as an alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(1) based on the alternative providing an acceptable level of quality and safety.

i YALVE INSERVICE TESTING RELIEF RE0 VESTS The licensee has indicat'ed that the valve inservice testing meets the requirements of OH-10 a', modified by i 50.55a(b)(2)(vii) regarding containment isolation valves leakage rate testing, and that safety and relief valve testing is conducted in accordance with OM-1-1987. The scope statement in Section 3.2 of the IST program for safety and relief valves does not appear to be consistent with all Class 1, 2, and 3 valves that provide overpressure protection; however, the applicable valves are included in the program.

The valves subject to IST are listed in the valve table in the program document. The table identifies the actuator type, design features, safety functions, and applicable testing requirements for each valve. The licensee has identified seven instances in which relief from the code is required.

Detailed notes describe the basis for deferring testing to cold shutdown or refueling outages. A review of these justifications indicate that the basis for deferral of testing is adequate. The relief requests are discussed below.

Relief Recugit E This relief request relates to setpoint testing the pressurizer relief and main steam safety valves in accordance with OH-1 requirements for an in-situ test prior to startup of Comanche Peak Steam Electric Station, Unit 2. The request is not applicable to Unit 1. It is a revision of the request submitted February 3, 1992. The revision does not change the technical basis or the alternative testing. The staff approved Relief Request V-1 in NUREG-0797, " Safety Evaluation Report Related to Operation of Comanche Peak Steam Electric Station, Unit 2," Supplement 25, Section 3.9.6, September 1992.

Because the approval is not affected by the revision, no further evaluation is required.

Egljff Reauest V-2 The request includes a number of pairs of Cate'}ory A/C or Category C, Class 3, series check valves which form the boundary between the nonsafety instrument air or nitrogen supply systems and the safety-related accumulator and receiver tanks for certain safety-related components. The check valves are required to l close upon failure of the air or nitrogen supply system to contain the compressed gas in the tanks. Relief is requested from the requirements of OH-10, 4.3.2, " Exercising Tests for Check Valves."

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7 Licensee's Basis for Relief The licensee stated 'Each valvo listed is one of two check valves in series at the inlet to a safety-grade accumulator or receiver tank. In each case, only one check valve is required in order to meet the safety class interface criteria of ANSI N18.2a-1975. However, two eneck valves are provided for added reliability, not for redundancy. The safety-related comoonents served by the accumulator and receiver tanks are redundant to other similar components which have their own dediceted safety-grade air supplies. As long as one of the check valves in the pair is capable of closure, then the safety analysis assumptions for the check valves are met. Some of the check valve pairs do not have provisions for testing each valve individually. However, the closure capability of each pair of check valves can be verified."

Alternative Testino The licensee proposed "Each pair of series check valves will be exercise tested at the required frequency by some positive means to verify the closure capability of at least one of the valves. No additional exercise testing will be performed unless there is an indication that the closure capability of the pair of valves is questionable. In that case, both valves will be declared inoperable and not returned to service until they are either repaired or replaced

• Evaluatjm1 The relief request relates to the e.xercising of these series check valves, not to leakage testing. The Code requires periodic verification of a check l valve's capability to function to its safety position to ensure that the plant

operates within its safety analyses. For series check valves when only one of a pair is required to meet safety analysis assumptions, the staff has j determined that the intent of Code requireeents is met and that it is l acceptable to test the pair of valves as a single va?ve with the following provisions: (1) both valves must be subject to comparable quality assurance requirements, (2) acceptance criteria for the pair of valves must be established appropriate to the verification method, and (3) if the accepttnce criteria are not met, both valves shall be declared inoperable and corrective actions initiated for both valves, including a retest prior to returning the pair of valves to service. The relief request includes these stipulations.

The alternative is acceptable because the tests verify the requirements of.the plant's safety analysis for the valves and meet the intent of the Code requirements. Additional justification is based on the corrective actions required for both valves when acceptance criteria are not met to ensure that at least one of the two valves continue to function to meet safety analysis-assumptions. Therefore, the proposed alternative provides an acceptable level of quality and safety.

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C.gtglusion 1he licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a (a)(3)(i) because the alternative provides an acceptable level of quality and safety.

Relief Regqcst V-3 The Category A/C valves included in Relief Request V-2 above are the subject of this relief request. These series check valves require leakage testing in addition to exercising. Relief from the requirements of OH-10, 4.2.2, " Valve Seat Leakage Rate Test," is requested.

Licensee's Elsis for Relief The licensee stated "Each valvo listed is one of two check valves in series at the inlet to k safety-grade accumulator or receiver tank. In each case, only one check valve is required in order to meet the safety class interface criteria of ANSI N18.2a-1975. However, two check valves are provided for added reliability, not for redundancy. The safety-related components served by the accemulator and receiver tanks are redundant to other similar components which have their own dedicated safety-grade air supplies. As long as one of the check valves in the pair is capable of meeting its leakage rate criteria, then the safety analysis assumptions for the pair of check valves are met. Some of the check valve pairs do not have provisions for testing each valve individually. However, the leakage rate of each pair of check valves can be verified."

Alternative Testina The licensee proposed "Each pair of series check valves will be leakage rate tested at the required frequency to verify acceptable seat leak-tightness of at least one of the valves. No additional leakage rate testing will be performed unless there is an indication that the seat leak-tightness of the pair of valves is questionable. In that case, both valves will be declared inoperable and not returned to service until they are either repaired or replaced."

Evaluation The relief relates to the leakage testing of these series check valves. The Code requires periodic verification of a check valve's leak-tight capability to ensure that the plant operates within its safety analyses. For series check valves when only one of a pair is required to moet safety analysis assumptions, the staff has detemined that it is acceptable to leak test the pair as a single valve with the following provisions: (1) both valves must be subject to comparable quality assurance requirements, (2) acceptance criteria for the leakage of the pair of valves must be 6.stablished, and (3) if the acceptance criteria are not met, both valves shall be declared noperable and corrective actions initiated for both valves, including a retest prior to

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returning.the pair of valves to service. The relief request-includes these stipulations. The alternative is acceptable because the leakage tests verify the requirements of the plant's safety analysis for the valves and meet the intent of the Code requirements. Additional justification is based on the .

corrective actions required for both valves when acceptance criteria.are not i met to ensure that--at least one of the two valves continues to function to .

meet safety analysis assumptions. Therefore, the proposed alternative -l provides an acceptable level of quality and safety.- l Conclusion .

The licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a.

(a)(3)(1) because the alternative provides an acceptable level of quality.and safety. -

Relief Reauest V-4 to disassemble check valves Relief from theoutage requirements to verify of OM-10, of4.3.2.4(c)he containment spray heade every refueling operability t and pump suction check valves is requested.  :

Alternative Testina' '

The licensee proposed to implement the sampling pr73 ram allowed.in Gl. 89-04, 7:

Position 2, which allows only:a sample of the check valves to be disassembled ~-

each refueling outage.

Evaluation .

The licensee has followed the guidance in Positiran 2 of GL 89-04. Because the staff has approved this alternative in GL 89-04,Lno additional evaluationtis.

necessary. The implementation of the disassembly and-inspection in accordance with Position 2 is subject to NRC inspection.

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The licensee's proposed alternative is-authorized pursuant to 10 CFR  ;

- 50.55a(a)(3)(1);because the alternative provides- an-acceptable level.of: l quality and safety.

Relief Reausst'V-5

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Relief from the requirements of OM-10, 4.3.2,' .' Exercising Tests for Checki Valves," for the reactor. coolant pump. seal injection and charging pressure -

boundary isolation check. valves is. requested.  ;

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Licensee's Basis for Relief The licensee stated "Each sair of valves listed constitutes two check valves-in series at a CVCS/RCS lciemical volume control system / reactor coolant system) interface. Two Jafety Class I check valves are provided in accordance with the safety class interface criteria of ANSI N18.2A-1975 in order to isolate the interfacing Class 2 system. Either of the check valves provided can perform this function. The system design, however does not include the test connections necessary to close exercise test each,of the series check valves individually. The system design does include sufficient test connections to verify the check function of each pair of valves (i.e., ,

v6rification that at least one of the valves will close).  :

Offsetting the inabliity to separately test each series check valve are the following design features:

1. Both of the Class I check valves at each interface lie within the secondary shield wall inside containment and thus are afforded protection from dynamic events and missiles generated elsewhere in containment.

2. The interfacing portions of the CVCS system are designed and constructed as Safety Class 2 and are seismically qualified.

3. The interfacing portions of the CVCS system are designed for pressures greater than or equal to RCS pressure.

4. Upstream of each of the subject check valve pairs, the interfacing CVCS lines contain a separate containment isolation check valve and power "

operated valve which are close exercise tested individually."

Alternative Testina The licensee proposed 'Each pair of series check valves will be exercise tested at the required frequency by some capability of at least one of the valves. positive means to No additional exercise' verify the closure testing will be performed unless there is an indication that the closure capabG ity of the.

- pair of valves is questionable. In that case, both valves will be declared .

inoperable and not returned to service until they are either repaired or replaced."

Evaluation-The chemical voluma control system maintains the water level in the -

pressurizer therefore maintaining reactor cool ut system (RCS)-water inventory. It also provides seal injection to reactor coolant pump seals, controls chemistry of the reactor coolant system, provides emergency core 7 p cooling in the event of a loss of coolant accident (LOCA), and allows a means l for filling,-draining, and-pressure testing the reactor coolar,t system during shutdown conditions. The subject valves provida the reactor coolant pressure ,

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t boundary hetMaen the reactor coolant systam and the chemical volume control system. Tuss valves are not listed in Technical Specification Table 3.4-1 as pressure isolation valves. Pressure isolation valves are defined in GL 87-06,

" Periodic Yertftcation of leak Tight Integrity of Pressure Isolation Valves',

as any two valves in series within the reactor coolant pressure boundary which sop m id the high pressure reactor coolant system from an attached low pressur9 system. The CVCS is a high pres Nre system at the interface.

Therefore, the pair of series check valve. could be considered as a single valve with anotner valve such as the containment isolation check valve providing the second high-to-low pressure interface. The relief request indicates that the CIV check valve is exercise tested periodically.

SAR Section 3.60.1.2.2,'LOCABreakPropagationCriteria,'statesthat"[a loss of reactor coolant accident is assumed to occur for a branch line brea

. . down to and including the second check valve (Case III in SAR figure 3.6B-

10) on incoming lines normally with flow. A pipe break beyond the restraint or second check valve will not result in an uncontrolled loss of reactor coolant if either of the two valves in the line closes.'

Based on the information in SAR Section 3.68.1.2.2, it ap) ears that both valves are credited for single failure assumptions at eac1 of the subject RCS/CVCS interfaces. While verifying that at least one of the two valves is closed would be acceptable if only one valve were required, the Itcensee should develop an additional snethod to verify that both valves close. A. >

nonintrusive method that may prove to be effective for these 2 and 3 inch valves is radiography, if no nonintrusive method is available, a periodic disassembly and inspection is an acceptable alternative if performed in accordance with the guidance in GL 89-04, Position 2. Additionally, if the licensee has information which provides further insight for the single failure assumptions, the relief request should be revised and resubmitted.

NOTE: Figure 3.68-10, Case III, depicts a single test connection upstream of the two series check valves. However, the isometric drawings that depict these six sets per unit of series valves show the test connections downstream (flow into RCS). Therefore, it appears that a leakage test of the pair of valves using a downstream test connection in the lines which each contain a third check valve and a power-operated valve which function as containment isolation valves (CIV), and a manual valve between the second check valve and the CIV check valve, may not verify that the series check valves are closed.

The licensee should review this issue and ensure that the testing performed for these valves is adequate to verify closure.

Conclusion The proposed alternative testing is not consistent with statements in the SAR; therefore, the proposal cannot be authorized. By letter dated January 21, 1993, the licensee committed to address this issue, either by submitting a revised relief request or developing a method for verifying that each of the valves function closed and withdrawing the relief request. These actions will be completed by July 1, 1993.

Because the licensee has proposed to address this issue prior to the next refueling outage, it is likely that this issue will be resolved before the test is scheduled to be performed. In addition, because this issue is not a significant safety concern, the licensee's proposed testing is acceptable l until startup from the third refueling outago. '

Relief Reagest V-6 Relief from the requirements of OH-10, 4.3.2, " Exercising Tests for Check Valves," for Category C, Class 3, check valves which form the boundary between the nonsafety demineralized water system or waste processing system and the safety-grado reactor makeup water storage tank (RHWST) to preclude draining the RHWST upon failure of the nonsafety systems (four valves each unit).

Licensee's Basis for Relief The licensee stated "Each pair of valves Itsted constitutes two check valves in series at a Class 3/Nonsafety piping interface. Two Safety Class 3 check valves are provided in accordance with the safety class interface criteria of ANSI N18.2-1975 in order to isolate the interfacing nonsafety system. Either of the check valves provided can perform this function. The system design, however, does not include the test connections necessary to close exercise test each of the series check valpes individually. The system design does include sufficient test connections to verify the check function of each pair of valves (i.e. verification that at least one of the valves will close).

Offsetting the inability to separately test each series check valve is the availability of the other unit's RMWST. Each unit's RMWST normally provides inventory for makeup to various safety-related systems in that unit via the Reactor Makeup Water Pumps. The two units' Reactor Makeu) Water Pumps, however, are cross-connected (but normally isolated) at t1eir suction, discharge and miniflow lines such that either the Unit 1 RHWST or the Unit 2 RMWST can be aligned to supply any of the Reactor Makeup Water Pumps users in either unit. In the unlikely event that one unit's tank contents are lost through a makeup line failure in combination with the failure of both makeup line check valves to close, the other unit's tank would be unaffected."

Alternative Testing The licensee proposed 'Each pair of series check valves will be exercise tested at the required frequency by some positive means to verify the closure capability of at least one of the valves. No additional exercise testing will be performed unless thera is an indication that the closure capability of the pair of valves is questionable. In that case, both valves will be declared inoperable and not returned to service until they are either repaired or replaced.'

Evaluation The relief request relates to the exercising of those series check valves to verify closure. The Code requires periodic verification of a check valve's capability to function to its safety position to ensure that the plant

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operates within its safety analyses. For series check valves when ,1y one of a pair is required to meet safety analysis assumptions, the staff has determined that it is acceptable to test the pair as a single valve with the following provisions: (1) both valves must be subject to comparable quality assurance requirements, (2) acceptance criteria for the pair of valves must be established appropriate to the verification method, and (3) if the acceptance criteria are not met, both valves shall be declared inoperable and corrective actions initiated for both valves, including a retest prior to returning the pair of valves to service. The relief request includes these stipulations.

The relief request does not specifically state that the safety analysis does a review of not credit bothsections the applicable valves for did single failure not identify anyassumptions; however,ipulate statements that st both valves are required. Therefore, the alternative is acceptable because the tests verify the safety requirements for the pair of valves. Additional justification is based on the corrective actions required for both valves when acceptance criteria are not met to ensure that at least one of the two valves continue to function to meet safety analysis assumptions. Therefore, the proposed alternative provides an acceptable level of quality and safety.

Conclusion The licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a (a)(3)(1) because the alternative provides an acceptable level of quality and safety in meeting the intent of the Code requirements.

Relief Reouest V-7 The licensee has determined that exercising the safety injection accumulator check valves quarterly or during cold shutdowns is impractical. Their determination is included ir, Note 8 of Table 13 - Safety Injection System, of the IST Program. Relief from the requirements of OH-10, 4.3.2.4 disassemble check valves every refueling outage to verify operab(c) ility of to the safety injection accumulators to RCS/RCS pressure isolations isolation valves is requested.

Alternative Testina Alternatively, the licensee proposes to implement the sampling program allowed in GL 89-04, Position 2, which allows only a sample of check valves to be disassembled at each refueling outage.

Evaluation The licensee has followed the guidance in Position 2 of GL 89-04. Because the j staff.has approved this alternative in GL 89-04, no additional evaluation is l

necessary. The implementation of the disassembly and inspection in accordance L with Position 2 is subject to NRC. inspection. The use of disassembly and inspection for these valves is for exercising requirements only and does not verify leak-tightness for their pressure isolation function. Leakage testing l

s l is performed according to the schedule and requirements of Technical Specification 4.4.5.2.2 which meets the Code requirements.

Conclusion The licensee's proposed alternative is authorized pursuant to 10 CFR 50.55a(a)(3)(1) because the alternative provides an acceptable IcVel of quality and safety in meeting the intent of the Code requirements.

MGMENTATION OF IST PROGRAM Chemical volume control system valves 8510A and 85108 have been categorized as reller valves by the licensee and as such are proposed to be set pressure tested at a nominal ten-year testing frequency in accordance with the 1989 Edition of Section XI of the ASME Code. However, the staff has determined that these valves perform the safety functions of opening to assure adequate flow in the alternate minimum flow lines and of closing to assure integrity nf the high head safety injection (HHSI) system. Specifically, the valves open-to prevent the HHSI pumps from deadheading following a safety injection signal and close to assure HHS! flow for emergency core cooling. The staff has  ;

determined that in order to properly assure these safety functions for these' '

valves, the testing must be performed more frequently than would be required for relief valves whose function is that of system overpressure protection.

The licensee submitted a letter dated January 18, 1993, committing to perform the following augmented inservice test .ig on these valves:

1. A minimum of one of the valves shall be set pressure tested each fuel cycle. Both valves shall be tested within two fuel cycles. '

2. If one valve fails a set pressure test, the other valve shall be tested.

3. Both valves shall be set pressure tested, inspected and refurbishtd as necessary following any system actuation requiring valve discharge.

This testing, inspection, and refurbishment shall be performed at the next cold shutdown of sufficient duration to perform these activities.

E110Ei The reviews performed for this SE did not include verification that all pumps and valves within the scope of 10 CFR 50.55a and Section XI are contained in the IST program. Additionally, for the components included in.the IST program, all applicable testing requirements were not verified. Therefore, the licensee is requested to provide the NRC with a description of the. process used in developing the IST program. The submittal should include, as a minimum, details of the documents used, the method of determining. if a component requires inservice testing, the basis for the testing required, the basis for categorizing valves, and the method or process used for maintaining the program current with design modifications or other activities performed under 10 CFR 50.59. It could be incorporated.into the IST program in

d.

s appropriate sections. By letter dated January 21, 1993, the licensee committed to :;ubmit this report by July 1,1993.

ER0 GRAM REVISIONS The licensee, in a phone conference held October 7, 1992, indicated that a revision to the inservice tesing program is being processed. The revision does not im)act any of the relief requests evaluated in this SE. -The licensee indicated t1st a number of passive valves which have recently benn identified as requiring position indication verification will be added to the inservice-testing program. The information requested in above could be submitted with the revised inservice testing program when the revision is complete, if it is available at that time. If the revision includes any new relief requests that require NRC approval, they will bo assessed at that time.

CONCLUSION Based on the review of the licensee's IST program relief requests, the staff concludes that the relief requests and IST program augmentation, as evaluated by this SE will provide reasonable assurance of the operational readiness of the pumps and valves to perform their safety related function, provided the inconsistency regarding relief request V-5 is addressed prior to startup from the third refueling outage. The staff has determined that granting relief,_

pursuant to 10 CFR 50.55a(f)(6)(1) is authorized by law and will not endanger life or property, or the common defense and security and is otherwise in the public interest.

Future revision to the program involving new or revised relief request or alternative testing should not be implements prior to approval by the NRC staff according to Technical Specification 4.0.5. New or revised relief request that meet the positions in Enclosure 1 of GL 89-04 should be submitted '

to the NRC staff, but can be implemented provided the licensee amends its program as necessary to confona with Code-requirements. Technical Specification requirements, and the staff approved alternatives as explained in attachment I to the GL. Program Thanges that add or delete components from the IST program should also be periodically-provided to the NRC.

Principal Contributor: Patricia Campbell Date: January 29, 1993 l

Table 1 Safety Evaluation for Inservice Testing Program Relief Requests

- Comanche Peat steam Electric station, Unit I and 2 Docket Numbers 50-445 and 50-446 1...

Setlef messamat shedser 'D CM ' SomeMyelen of metief amesmoted suc acties

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P-1 nellef frue the recpirmante of m-6,16.1 erd Table 3b, associated with the timite en etternettwe to authertaed por for flow, pressure, eruf vibration aseeuremente for peelttwe dieptecountet pimpe le 150.55e 1 (e)(3)(l) hr=== the respJested for the dieset generator fuel cit treriefer pwpe. These pimpe are rotary preposet provideo en ecceptable pumpe of austa e doelen thet they operated more eleoely to centrifugal gompe. The tevel of quotity eruf eefety.

preposed etternettwo 14 to apply the tielte of M-6 for centrifuset pamps to the fust eit trenefer pimpo.

V-1 Relief fram the preservice test regairoaante of M-1-198T to perfera e setpoint test The staff approved thfe relief of the esin steam eefety wetwee and the pressurizee relief wetwee trir preesurizing request in auSEE-0?97, Scfttr the respective systems (main eteen eyotes and reactor coetent systse) to the set Evetation teort metated to pressure of the welwee le resposted. Alternettwely, the Licensee proposed to Omeestiert of remenche Peeit steen

' perform the setpoint testing at a test facility seus not aihjeet the eyetens to the Electric statiert unit 2, increased preneure. se.eptement 25, section 3.9.6, setember 1997.

V-2 metlef from m -10, 1 4.3.2, for irdividuetty verifying stesure of paire of eerlee The etternettve le authorized per r%eck vetwee in the instriment air or nitrogen eierty eyetems, le respeeted i 50.55e 1 tem 3)(l) tusceuse the Attornetively, the licerece p. , d to teet the watwee in petro. Seth we!ves are proposet providne en acceptable not respleed for eefety enetysle oestaptione to be met. towet ef getity and eefety, i' V-3 Relief fress m -10, 1 4.2.2, for indiv5<4mity verifyles toek-tightness of pelre of The siternettve is authertaed per series check witsee in the instrument air or n!treges enopty ersteem, le regsmeted. I SC.55e 1 (sM3 MI) because the Alteramtively, the licensee proposed to test the wolves in pelre. Be.th wolves are oreposet provides en ecceptable

i. not regriced for eefety enelyste sceneptions to tse set. tevet of gastity and eefety. l t

V-4 The licensee leptemente m-10,14.3.2.4(c), to use di-w 8.y and inspection to The use of GL m es, Peeltion 2, esercise the centeinment sprey needer and pump suction chect vetwee. The retlef gasidence le apprs ed per GL St-M, regnet indicates that the guldence of GL 49-06, Positten 2, ellt tse used to apply a proviend the ticanese comply witti easyttas program for these wetwee auch that ene volve allt be inspection durieg each the widence delineateel in the ,

refuelleg outage. The dieeseemesty and inspectiers program will comply with the poe lt f ort. If a nonintrusive t w idence in Peeltion 2. method le dewetaped, the rollef recpest should be detered.

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telief Regaret Ihadner Descriptian of Netief Reqb e ted ' EBC Action i

V-5 Relief frae the re w iremente of on-10, 1 4.3.2, for the reactcc coolant purp seat The sAa aspears to credit betti ,

fr.jectiori and chuging prezcure t>maidsty isolation c*mck vetces ic requested. The volves its escit pair of vetwes '

ticermee prgoses to verify that each petr of seeies check velves le tested as e neject to tMs relief retpasst.

single welve for testing purposes. The atteenstive is not esprewed.

Testlig is te verify the fwetlan of these vetves. individetty by the end of 18r03 for (mit 1 arid by the eruf of the first refueling outage for urif t 2. The anerteriy closure verification of the pele of volves should centivene until the licensee develope e mothed, modifies the test c1peectiere, or provides additionet hetificetten for the proposed mothed by time acteede spectffed.

V-4 Rollef from the requiremente of tel-10, j 4.3.2, for check volw pelre edtich form the !"e m etternettve is suttrstred per boundary botessen the noruefety dominerellaed eeter systen er esente proceseirg i 50.55e 1 (e)(3)(l) haceuse the system and time oefety-gresie reacter makeg water starsee tank to recreated. proposet previens en acceptabte Attornettwety, the licensee preposes to esercise the wtwee in poles. towet of getity erei eefety.

V-T The licensee Septements fut-10,14.3.2.4(c), to use disenemy eral inspectlen to The use of E 89-06, Penttic. s, esorrise the oefety injectiert -deter descat volves. The retlef re;uest seidence is approwed por k 89-06, Indicates thet time guidance of E 89-06, Peeltten 2, witi be wood to appty e provided the 1lessioe- compty with eseptive program for these volves oude that one volve witt he inspection ehrl4 each the guidurre sistFmted in the refuellte outsee, the dieseeembly and inspection program wilt comply crith the positten. If G nanintrusive guldunce in Positten 2. : Leek testins of these wetwee is perforund accordfre to the mothed le # m teped, the retles achedde and re.pirement of fedenicet speelficetf an 4.4.5.2.2. roepest cands he deleted.

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