ML19344D635
| ML19344D635 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 03/31/1980 |
| From: | Fehringer J, Rockhold H EG&G, INC. |
| To: | Nerses V Office of Nuclear Reactor Regulation |
| References | |
| CON-FIN-A-6258 EGG-EA-5117, NUDOCS 8004250364 | |
| Download: ML19344D635 (46) | |
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A INTERIM REPORT Accesion No.
Report No.
EGG-EA-5117 Contract Program or Project
Title:
Systems Engineering Support Subject of this Document:
Safety Evaluation of the Inservice Testing Program for Pumps and Valves at Zion Units 1 and 2 (Docket Nos. 50-295 and 50-304) for the Period 1-17-18 through 9-16-79 Type of Document:
Safety Evaluation Report Author (s):
J. M. Fehringer H. C. Rockhold Date of Document:
March 1980 Responsible NRC Individual and NRC Office or Division:
Victor Nerses, NP.C-DOR This document was prepared primarily for preliminary or internal use. it has not received full review and approval. Since there may be substantive changes, this document should not be considered final.
EG&G Idaho. Inc.
Idaho Falls, Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C.
Under DOE Contract No. DE-AC07 761D01570 NRC FIN No. A6258 INTERIM REPORT NRC Research and Technica Assistance Repert 8004250 3 6 4
EGG-EA-5117 March 1980 SAFETY EVALUATION REPORT, INSERVICE TESTING PROGRAM, ZION UNITS 1 AND 2 - DOCKET NOS. 50-295 AND 50-304 J. M. Fehringer H. C. Rockhold U.S. Department of Energy Idaho Operations Office = idaho National Engineering Laboratory S i' b@
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FORM EG4G 398 ca is ni INTERIM REPORT Accession No.
Report No.
EGG-EA-5117 Contract Program or Project
Title:
Systems Engineering Support Subject of this Document Safety Evaluation of the Inservice Testing Program for Pumps and Valves at Zion Units 1 and 2 (Docket Nos. 50-295 and 50-304) for the Period 1-17-78 through 9-16-79 Type of Docisment:
Safety Evaluation Report Author (s):
J. M. Fehringer H. C. Rockhold Date of Document:
March 1980 R:sponsible NRC Individual and NRC Office or Division:
Victor Nerses, NRC-DOR This 'Mcument was prepared primarily for preliminary orinternal use. it has not received full review and approval. Since there may be substantive changes, this document should not be considered final.
EG&G Idaho, Inc.
Idaho Falls. Idaho 83415 Prepared for the U.S. Nuclear Regulatory Commission Washington, D.C.
Under DOE Contract No. DE-AC07 76lD01570 NRC FIN No. A6258 INTERIM REPORT NRC Research and _iechn.
- cat Assistance Report
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TABLE OF CONTENTS i
Page I.
I ntroduc ti on........................
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II. Pump Testing Program...................
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I r.
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III. Valve Testing Program 9
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IV. A t t ac hm en t I.......................
37 1
V.
Attachment II 38 1
I VI. Att achment I I I......................
40 4
4 j
t VII. Attachment IV 41 J
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Introduction Contained herein is a safety evaluation of the pump and valve inservice testing (IST) program submitted by the Commonwealth Edison Company (CECO) 5-27-78 for its Zion Units 1 & 2 nuclear plants. The program applies to Zion Units 1 & 2 for the period 1-17-78 through 9-16-79. The working session with Zion Units 1
& 2 and CECO representatives was conducted on 12-13-78 and 12-14-78. The licensee re-submittal was issued on 6-28-79 and was reviewed by EG&G Idaho,Inc., to verify compliance of proposed tests of safety related Class 1, 2, and 3 pumps and valves with l
requirements of the ASME Boiler and Pressure Vessel Code, Section
(
XI,1974 Edition, through the Sumer of 1975 Addenda.
Comonwealth Edison Company has also requested relief from the ASME Code from testing specified pumps and valves because of I
practical reasons. These requests have been evaluated individually to determine whether they have significant risk implications and whether the tests, as required, are indeed impractical.
j The evaluation of the pump testing program and relief requests for pumps is contained in Section II below; the evaluation of the valve testing program and associated relief requests is I
contained in Section III. All evaluations for Sections II and III are the recommendations of EG&G Idaho, Inc.
t Appendix J exemption requests for category A valves currently i
being reviewed by the NRC are contained in Attachment I.
Category A, B, and C valves that meet the requirements of the
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ASME Code Section XI and are not exercised every 3 months are contained in Attachment II.
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A listing of P&ID's used for this review are contained in Attachment III.
Valves that are never full stroke exercised or that have a testing interval greater than each refueling outage and rqlief requests with insufficient technical basis where relief is not recomended are sumarized in Attachment IV.
II. Pump Testing The IST program submitted by Comonwealth Edison Company was examined to verify that all Class 1, 2, and 3 safety related pumps were included in the program and that those pumps are subjected to the periodic tests as required by the ASME Code,Section XI. Our review found that all Class 1, 2, and 3 safety related pumps were included in the IST program ar,a, except for those pumps identified below for which specific relief from testing has been requested, the pump tests and frequency of testing comply with the code.
Each Comonwealth Edison Company request for relief from testing pumps, the code requirement for testing, the basis for requesting relief, and the EG&G evaluation of that request is sumarized below and grouped according to the system in which the pumps reside.
A.
Service Water (SW-001, SW-002, SW-003)
Auxiliary Feedwater (FW-005, FW-006)
ContainmentSpray(CS-001,CS-002,CS-003)
Volume Control (VC-006,VC-007) i Residual Heat Removal (RH-001, RH-002)
ComponentCooling(CC-003,CC-004,CC-005,CC-006,CC-007) 1 Safety Injection (SI-003, SI-004) l i
2
1.
Relief Request The licensee has requested specific relief from the requirements of Section XI Table IWP-3100-2 for the method of testing and allowable ranges for pump l
vibration measurements for all safety related pumps listed above.
I Code Requirement l
An inservice test shall be conducted on all safety related pumps, nominally once each month during normal 1
plant operation. Each inservice test shall include the measurement, observation, and recording of all quantitites in Table IWP-3100-1, except bearing temperature, which shall be measured during at least l
one inservice test each year. The allowable ranges of inservice test quantities, in relation to the reference values, are tabulated in Table IWP-3100-2.
In the i
event these ranges cannot be met, the owner shall 1
specify in the pump record the reduced range limits to I
allow the pump to fullfill its function, and those limits shall be used in lieu of the ranges given in 4
Table IWP-3100-2 for the monthly pump test.
Licensee's Basis for Requesting Relief l
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The component as designed and installed does not have instrumentation for the monitoring of vibration I
amplitudes of the rotating shaft as required by j
IWP-4510.
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Portable vibration sensing equipment is available to l
monitor vibration parameters. The normal maintenance routine is to monitor vibration velocity in inches per second. This allows a more accurate determination of abnormal vibration at frequencies other than the shaf t rotational speed. The " General Machinery Vibration Severity Chart" published by IRD Mechanalysis, Inc.
will be used as a guideline. The " alert range will be O.314 in/sec < V < 0.628 in/sec.
The required action range will be V 20.628 in/sec.
The test frequency will be as specified in IWP-3000.
Evaluation i
The proposed alternate method of measuring pump vibration with the portable vibration monitoring equipment currently available at the plant site meets
~l the intent of the code.
Sis e the units of measure of inches /second is different than that specified by the code (mils-peak-to-peak), a chart indicating the alert action and required action ranges is provided in the IST program. We feel relief should be granted from the
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ASME Code specified method of measurement and feel the licensee's alternate test method meets the intent of the code and provides the information needed for analysis of pump degradation.
B.
Service Water (SW) Pumps (SW-001, SW-002, SW-003) 1.
Relief Request
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The licensee has requested specific relief from the Section XI requirement to measure service water pumps inlet pressure (P ) and flowrate (Q).
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Code Requirement An inservice test shall be conducted on all safety related pumps, nominally once eu.h month during normal plant operation. Each inservice test shall include the measurement, observation, and recording of all quantities in Table IWP-3100-1, except bearing temperature, which shall be measured during at least one inservice test each year.
Licensee's Basis for Requesting Relief
'j The service water pumps are vertical design with no means of direct inlet pressure measurement as required by IWP-4200.
Inlet pressure to these pumps will be established by reference to the level of lake water above the pump suction. Due to the demands of dependent systems, the individual testing of service water pumps as required by IWP-3400(a) would jeopardize
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safe plant operation. The plant design does not incorporate any flow measurement instrumentation.
Technical Specification 3.8.7 8 & C requires all three service water pumps to be operable.
If one of the three pumps is found inoperable, reactor operation is permissible for the seven succeeding days.
In addition the service water systems are crosstied between the two units as described in the FSAR. Correct performance of-these pumps can only be assessed on their continued ability to perform the function for which they were installed.
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Evaluation We agree with the licensee's basis, and therefore feel relief should be granted from the Section XI requirements to measure Pj for the service water pumps SW-001, SW-002, and SW-003. The calculation of the static pressure at the pump suction by measuring the lake level is an adequate alternate to actually measuring the pressure. However, since the service water pumps are located in a variable resistance system, the code requires the measurement or calculation of both differential pressure and flow rate. We feel the utility has not fully investigated the alternate tests for detennining the hydraulic performance of these pumps. The tests they are performing only evaluate the mechanical condition of these pumps. Therefore, we feel relief should not be granted unless an alternate test can be performed that will evaluate the hydraulic characteristics of these pumps.
C.
Component Cooling (CC) Pumps (CC-003, CC-004, CC-005, CC-006,CC-007) 1.
Relief Request The licensee has requested specific relief from the Section XI requirement to measure inlet pressure (P ), differential pressure (dP), and flowrate (Q),
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for component cooling pumps CC-003 through CC-007.
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Code Requirement An inservice test shall be conducted on all safety related pumps, nominally once each month during normal plant operation. Each inservice test shall include the measurement, observation, and recording of all quantities in Table IWP-3100-1, except bearing temperature, which shall be measured during at least one inservice test each year.
Licensee's Basis for Requesting Relief Due to the demands of dependent systems, the individual 3
testing of component cooling pumps as required by IWP-3400(a) would jeopardize safe plant operation.
Technical Specification 3.8.6 A & B requires a minimum of 3 component cooling pumps operable with one reactor critical. Of the 5 component cooling pumps, one can be inoperable without any effect on the system. Technical Specification 3.8.6C requires some action if 2 pumps are inoperable only with two reactors critical. One reactor may operate indefinitely in this condition.
The design heat load is such that two pumps are required to operate during normal plant operation and three pumps are required with one unit at full load and the other shut down (para. 9.3.2 of the FSAR). There is no plant operating condition when a single pump could be run to determine performance parameters as i
required by IWP-3400(a).
These pumps are visually checked at least once every 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> shift by the equipment attendant as part of a required routine.
Instrumentation is installed which will permit the recording of the inlet pressure at each 7
pump.
However, pressure measurement on the pump discharge can only be monitored at the common discharge header. The plant design does not incorporate any flow measurement instrumentation. Correct performance of these pumps can only be assessed on their continued ability to perform the function for which they were installed.
Evaluation Section XI of the ASME Code specifically identifies the parameters to be measured which describe the mechanical condition and the hydraulic condition of the pumps being tested.
The licensee is not measuring any of the parameters which describe the hydraulic condition of these pumps.
Therefore, we fael relief should not be granted from measuring Pi, dP, r.nd Q for the service water pumps. We feel the licer.see has not fully investigated the alternate tescing methods available for evaluating the hydraulic condition of these pumps.
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III. Valve Testing Program The IST program submitted by Commonwealth Edison Company was examined tn verify that Class 1, 2, and 3 safety related valves were included in the program and that those valves are subjected to the periodic tests required by the ASME Code,Section XI, and the NRC positions and guidelines. Our review found that Class 1, 2, and 3 safety related valves were included in the IST program and, except for those valves identified below for which specific relief from testing has been requested, the valve tests and frequency of testing comply with the code requirements and the NRC positions and guidelines listed in General Section A.
Also included in the General Section A is the NRC position and valve listings for the leak testing of valves that perform a pressure isolation function and a procedure for the licensee's use to incorporate these valves into the IST program. Each Coninonwealth Edison Company request for relief from testing valves, the code
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requirement for testing, Coninonwealth Edison Company's basis for requesting relief, and the EG&G evaluation of that request is suninarized (8 through H) below and grouped according to each specific system.
A.
General 1.
Leak Testing of Valves which Perform Pressure Isolation Function There ::re several safety systems connected to the reactor coolant pressure boundary that have design pressures that are below the reactor coolant system operating pressure. There are redundant isolation valves forming the interface between these high and low pressure systems to prevent the low pressure systems from being subjected to a pressure which exceeds their design limits.
In this role the valves are performing a pressure isolation function.
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It is the NRC's view that the redundant isolation provided by these valves regarding their pressure isolation function is important. The staff considers it necessary to provide assurance that the condition of each of these valves is adequate to maintain this redundant isolation and system integrity. For this reason we believe that some method, such as leak testing, should be used to ensure the condition of each valve is satisfactory to maintain this pressure isolation function.
In the event that leak testing is selected as the appropriate procedure for achieving this objective, we believe that the following valves should be categorized as A or AC and leak tested in accordance with IWV-3420 of Section XI of the applicable edition of the ASME Code. These valves are:
RH-8701 and RH-8702 (RHR take-off from loop A hot leg)
RH-8736A and RH-8949A (RHR to loop A hot leg inlet check valves)
RH-8736B and RH-89498 (RHR to loop D hot leg inlet check valves)
SI-9001A through D (low head SIS check valves to loop cold legs)
SI-9002A through D (low head SIS check valves to loop cold legs)
SI-8948A through D (accumulator discharge check valves to loop cold legs)
SI-8956A through D (accumulator discharge check valves)
SI-8900A through D (BIT supply check valves to loop coldlegs) i i
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51-9032 (BIT discharge check valve to loop cold legs)
SI-9012A through D (SIS check valves to loop cold legs)
SI-8905A and B (SIS check valves to loop hot legs) i SI-9004C and D (SIS check valves to loop hot legs)
SI-8957A and B (RHR return check valves to loop cold le9s)
SI-9011A and B (SIS M0V's discharge to loop hot legs)
SI-8801A and B (BIT M0V's discharge to loop cold legs)
The NRC has discussed this matter and identified the valves listed above to the licensee. The licensee has agreed to consider leak testing each of these valves in accordance with IWV-3420 of the applicable edition of the ASME Code and to categorize these valves with the appropriate designation. If the licensee determines that leak testing is not necessary because there are other methods that the licensee has and will use to determine each valve's condition, the licensee shall provide to the NRC for evaluation on a valve-by-valve basis the details of the method used that clearly
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demonstrates the condition of each valve.
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2.
ASME Code Section XI Requirements Subsection IWV-3410(a) of the Section XI Code (which discusses full stroke and partial stroke) requires that Code Category A and B valves be exercised once every 3 months, with the exceptions as defined in IWV-3410(b-1),(e),and(f).
IWV-3520(a)erequires that Code Category C valves be exercised once every 3 months, with the exceptions as defined in IWV-3520(b).
IWV-3700 requires no regular testing for 5
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Code Category E valves.
Operational checks, with appropriate record entries, shall record the position of these valves before operations are performed and after operations are completed and shall verify that each valve is locked, or sealed. The limiting value of full stroke time for each power operated valve shall be identified by the owner and tested in accordance with IWV-3410(c).
In the above exceptions, the code permits the valves to be tested at cold shutdown where:
a.
It is not practical to exercise the valves to the position required to fulfill their function or to the partial position during power operation.
b.
It is not practical to observe the operation of the valves (with f ail-safe actuators) upon loss of actuator puer.
The staff stated its position to the licensee that check valves whose safety function is to open are expected to be full-stroked.
If only limited operation is possible (and it has been demonstrated by the licensee and agreed to by the staff), the check valve shall be partial stroked.
Since disk position is not always observable, the NRC staff stated that verification of the plant's safety analysis design flow rate through the check valve would be an adequate demonstration of the full-stroke requirement.
Any flow l
rate less than design will be considered part-stroke exercising unless it can be shown that the check valve's disk position at the lower flow rate would be equivalent to or greater than the design flow rate l
through the valve. The licensee agreed to conduct his flow tests to satisfy the above position.
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The licensee has stated that iione of the Category A or B power operated valves can be part-stroked because of the design logic of the operating circuits. These cicuits are such that when an open or close signal is received the valve must complete a full stroke before the relay is released to allow the valve to stroke in the other direction. We find that the above relief request from part-stroking is warranted and should be granted because the required function of the valves involves only full open or full closed positions.
3.
Cold Shutdown a.
Inservice valve testing at cold shutdown.
def!ned as: Valve testing should commence not later than 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> after shutdown and continue until complete or the plant is ready to return to power. Completion of all valve testing is not a prerequisite to return to power. Any testing not completed at one cold shutdown should be performed during the subsequent cold shutdowns to meet the code required testing frequency. We find the licensee's proposed cold shutdown condit hn testing acceptable, b.
The Code states that, in the case of cold shutdowns, valve testing need not be performed more often than once every 3 months for Category A and B valves and once every 9 months for Category C valves.
It is the NRC's pos'. tion that the code is inconsistent and that Catagoy C valves should be t1sted on the same schedule as Cctegory / ind B valves. The licene.ee has agreed to,tiodify a y procedures as neces.5ary on cold
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shutdown, to read, "In the case of frequent cold shutdowns, valve testing need not be performed more often than once every three (3) months for Category A, B, and C valves."
4.
Changes to the Technical Specifications In a November 1976 letter to the Commonwealth Edison Company the NRC staff provided an attachment entitled "NRC Staff Guidelines for Excluding Exercising (Cycling) Tests of Certain Valves During Plant Operation." The attachment stated that wnen one train of a redundant system such as in the Emergency Core Cooling System (ECCS) is inoperable, nonredundant valves in the remaining train should not be cycled since their f ailure would cause a loss of total system function. For example, during power operation in some plants, there are stated minimum requirements for systems which make up the ECCS which allow certain limiting conditions for operation to exist at any one time and if the system is not restored to meet the requirements within the time period specified in a plant's Technical Specifications, the reactor is required to be put in some other mode. Furthermore, prior to initiating repairs, all valves and interlocks in the system that provide a duplicate function are required to be tested to demonstrate operability imediately and periodically thereafter during power operation.
For such plants this situation would be contrary
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to the NRC guideline as stated in the document mentioned above.
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P 5.
Safety Related Valves This review was limited to those Class 1, 2, and 3 valves of Section X' of the ASME Code that are safety related. 'aafety related valves are defined as those that are needed to mitigate the consequences of an accident and/or shut down the reactor and to maintain the reactor in a shutdown condition.
It should be noted that the licensee may have included nonsafety related valves in their Inservice Test Program as a decision on the licensee's part to expand the scope of their i
Inservice Test Program.
B.
Safety Injection System (SI) 1.
Category C Valves a.
Relief Request l
The licensee has requested specific relief from full stroke exercising the following Category C check valves in accordance with the requirements of Section XI and proposed to full stroke exercise these valves during refueling outages.
SI-8922A and B safety injection pump discharge checks SI-9004C and D safety injection to hot legs checks SI-8949C and D safety injection to hot legs checks SI-8905A and B safety injection to hot legs checks SI-9012A, B, C, and D safety injection to cold legs checks i
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4 Code Requirement-Refer to valve testing paragraph A.2.
i Licensee's Basis for Requesting Relief i
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These check valves cannot be tested during unit operation as the shutoff head of the pumps is lower than reactor coolant. system pressure.
F.1 l
stroke testing of all the branch run check valves will be demonstrated by total pump discharge flow I
during cold shutdown providing the reactor vessel j
head is removed.
Performance of this test with the reactor coolant system depressurized but intact could lead to an inadvertant l
overpressurization of the system.
The alternative I
method of protecting against overpressurization by i
partial draining of the reactor coolant system to provide a surge volume is not considered a safe i
practice due to concerns of maintaining adequate
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water level above the reactor core.
f Evaluation i
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The licensee has demonstrated that quarterly exercising these valves cannot be accomplished since the shutoff head of these pumps is less than
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RCS pressure,' therefore we feel relief should be granted from the exercising requirements of j
Section XI for valves SI-8922A and B, SI-9004C-and D, SI-8949C and D, SI-8905A an'd B, and SI-9012A, B, C and D with an alternate test frequency of full stroke exercising each refueling outage.
The large volume of water required to i
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full flow / full stroke exercise these check valves would cause thermal shocking of injection nozzles during power operation and could result in an overpressurization of the RCS during cold shutdowns.
b.
Relief Request Specific relief is requested from quarterly and cold shutdown exercising check valves SI-9032, boron injection tank discharge to loop cold legs and SI-8900A, B, C, and D, boron injection tank supply to loop cold legs. An alternate test frequency of full stroke exercising each refueling outage is proposed.
Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief These check valves cannot be tested during unit operation as the ii.jection of cold, highly borated water would result in a change in reactor core reactivity and undue thermal cycling of the injection nozzles. Full stroke exercising of all the branch run check valves will be demonstrated by total pump discharge flow during cold shutdown providing the reactor vessel head is removed.
Performance of this test with the reactor coolant system intact could lead to an inadvertant overpressurization of the system. The alternative method of protecting against overpressurization by 17
partial draining of the reactor coolant system to provide a surge volume is not considered a safe practice due to concerns of maintaining adequate water level above the reactor core.
Evaluation 4
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The licensee has demonstrated that exercising these check valves during power operation would require injecting cold borated water from the Boron Injection Tank (BIT) into the loop cold legs. This would cause rapid power transients in addition to thermal shocking the injection nozzles. During cold shutdown full stroke exercising these check valves would require running a charging pump into the RCS and this could result in a low temperature overpressurization of the RCS.
Therefore, we feel relief should be granted from quarterly and cold shutdown exercising these check valves and the alternate test frequency of full stroke exercising SI-9032 and SI-8900A, B, C and D during each refueling outage is a sufficient alternate test to demonstrate valve operability.
c.
Relief Request Specific relief is requested from full stroke exercising Category C check valves SI-8948A, B, C, and D, accumulator discharge to loops and SI-8956A, B, C, and D accumulator outlet check valves.
An alternate test of partial stroke exercising during cold shutdowns is proposed.
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i Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief The accumulator check valves cannot be tested during unit operation due to the pressure differential between the accumulators (s600 psig) a,qd the reactor coolant system (2235 psig). These valves cannot be full stroke tested except by a I
rapid depressurization of the reactor coolant system as would occur during the design basis cold leg double guillotine break. These valves will be partial stroke tested during cold shutdown.
Evaluation The licensee has demonstrated that these valves cannot be exercised during power operation since the accumulator pressure is insufficient to overcome the Reactor Coolant System pressure.
During cold shutdown these valves can be partial stroke exercised but attempting to full stroke the I
valves could cause a low temperature overpressurization of the RCS since the expansion volume available is not sufficient to accomodate i
the large quantity of water discharged from the accumulators. Therefore we feel relief should be granted from the quarterly exercising requirements of Section XI for these valves. The alternate test of partial stroke exercising these valves during cold shutdowns and refueling outages is sufficient to demonstrate proper valve operability.
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d.
Relief Request Specific relief is requested from quarterly full stroke exercising SI-8926, SI pump suction check from RWST.
An alternate test of partial stroke 4
exercising qua-terly and full stroke exercising during refueling outages is proposed.
Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief b
This check valve cannot be full stroke tested during unit operation as the shutoff head of the pumps are lower than reactor coolant system
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pressure.
Partial stroke exercising of this check i
valve will be demonstrated by establishing proper pump discharge flow during periodic pump testing.
Full stroke exercising of this check valve will be demonstrated during cold shutdown providing the reactor vessel head is removed.
Performance of this test with the reactor coolant system intact could lead to an inadvertant overpressurization of the system.
The alternative method of protecting against overpressurization by partial draining of the reactor coolant system to provide a surge volume is not considered a safe practice due to concerns of maintaining adequate water level above the reactor core, 20 I.
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Evaluation The licensee has demonstrate.d that full stroke exercising this valve cannot be accomplished during power operation since the SI pumps cannot achieve full flow through the pump recirculation line and the pumps do not develop enough head to discharge into the RCS, During cold shutdowns an overpressurization of the RCS could occur if the SI pumps were to discharge into the RCS. We feel relief should be granted from the Section XI requirements to full stroke exercise this valve and feel the alternate test of partial stroke exercising quarterly and full stroke exercising during cold shutdowns with the reactor vessel head removed and during refueling outages is sufficient to demonstrate proper valve operability.
e.
Relief Request Specific relief is requested from Section XI requirements for exercising the following check valves:
SI-8957A and B RHR return to loop cold legs SI-9001A, B, C and D low head SIS to loop cold legs SI-9002A, B, C and D low head SIS to loop cold legs.
Code Requirement Refer to valve testing paragraph A.2.
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Licensee's Basis for Requesting Relief i
These check valves cannot be tested during unit operation as the shutoff head of the pumps is lower than reactor coolant system pressure. Full stroke exercising of all the branch run check l
valves can only be demonstrated by total pump l
discharge during cold shutdown providing the
'i reactor vessel head is removed.
This condition is required to establish suction from the RWST and provide system flow conditions similar to design injection flow.
Performance of this testing with the reactor coolant system depressurized but intact would not provide adequate surge volume for l
influx from the RWST to allow the RHR injection system to reach these design flows.
The alternative method of providing a surge volume by partial draining of the reactor coolant system is not considered a safe practice due to concerns of maintaining adequate water level above the reactor Core.
Evaluation The licensee has shown that exercising these valves during power operation cannot be I
accomplished since the low head safety injection pumps do not develop sufficient discharge pressure l
to overcome the RCS pressure holding these check l
valves shut.
However, we feel the licensee has the ability to perform a flow test on these check valves during cold shutdowns. While utilizing the RHR System for shutdown cooling these valves will l
be at least partial stroke exercised and a full stroke might be accomplished depending on the 22 t
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maximum flow obtainable during shutdown cooling as compared to design accident flow. Therefore, we feel relief should not be granted from the exercising requirements for these valves until the utility demonstrates that the testing is indeed impractical.
C.
Chemical and Volume Control System (VC) 1.
Category B Valves a.
Relief Request Specific relief is requested from quarterly exercising the following valves and an alternate test of full stroke exercising during cold shutdown when the reactor coolant pumps are not running is proposed.
VC-8372A, B, C, and D seal water supply to reactor coolant pumps VC-8369A, B, C, and D seal water supply to reactor coolant pumps Code Requirement i
i Refer to valve testing paragraph A.2.
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Licensee's Basis for Requesting Relief These valves function as containment isolation valves.
No valve seat leakage is specified as they are supplied with a water seal from the Isolation Valve Seal Water (IVSW) systems.
The operability of the IVSW system is functionally tested as part of this program.
These isolation valves are therefore listed as Category B valves.
Manually operated valves in the reactor coolant pump seal injection lines remain in a normally open condition during unit operation. Manually operated needle valves are adjusted to regulate seal injection flow to maintain correct pressure differentials at the pump seals.
The seal injection system remains in operation following any postulated accident contributing to the safety injection flow to the reactor coolant system while maintaining and protecting the pump seals.
Should it be required during a protracted accident these valves may be closed and provided with isolation valve seal water. These valves will be manually stroke tested each cold shutdown providing all reactor coolant pumps are not in operation. This testing period will be each refueling outage as a minimum. Relief is taken from measuring stroke time on manual valves.
Evaluation We agree with the licensee's basis and feel relief should be granted from the quarterly exercising requirements of Section XI for valves VC-8369A, B, C and D and VC-8372A, B, C, and D.
The alternate l
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exercising frequency of each cold shutdown that the reactor coolant pumps are not in operation is sufficient to demonstrate operability of these manual isolation valves. We also feel relief l
should be granted from measuring stroke time on these manual valves since this measurement would be meaningless.
b.
Relief Request Specific relief is requested from exercising l
manual valves VC-8480A and B, charging supply to l
loop fill header.
Code Requircment Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief i
These valves function as containment isolation valves. No valve seat leakage is specified as they are supplied with a water seal from the Isolation Valve Seal Water (IVSW) systems.
The operability of the IVSW system is functionally tested as part of this program. These isolation valves are therefore listed as Category B valves.
These manual valves are maintained passively closed during unit operation and are not required E
25
1 to function, other than to provide containment isolation, to safely shutdown the reactor or mitigate the consequences of an accident.
Exception is taken to the performance of exercising tests as required by IWV-3410.
Evaluation We agree with the licensee's basis and therefore feel relief should be granted from the exercising requirements of Section XI for valves VC-8480A and B.
These valves are in their safety related position and are not required to open or close to mitigate the consequences of an accident or safely shut down the plant.
The operability of these valves is inconsequential with regard to the safety function which they perform. We conclude that the quarterly stroke and stroke time measurements are meaningless for passive valves.
D.
Containment Spray System (CS) r 1.
Category C Valves a.
Relief Request Specific relief is requested from the exercising requirements of Section XI for valves CS-0016, CS-0021 and CS-0026, spray additive check valves.
An alternate test frequency of full stroke exercising one valve each year is proposed.
i Code Requirement Refer to valve testing paragraph A.2.
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Licensee's Basis for Requesting Relief Check valves in the spray additive system cannot be exercised without introducing Na0H contaminants into the spray system.
Operability of these three valves will be verified at a frequency of one valve each year. Operability will be verified by either disassembly of the valve to check for free movenent of the moving parts or by a special full flow flushing procedure.
Evaluation The licensee has shown that with the current piping configuration exercising these check valves by utilizing flow through them would introduce the highly corrosive spray additive (Na0H) into the
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main piping of the containment spray system and the refueling water storage tank.
This action would require extensive clean-up operations and generate considerable low level contaninated waste water to flush these systems free of the corrosive.
However, the licensee has not shown why each of these valves cannot be either disassembled or checked for full stroke exercising with a full flow flush each refueling outage.
Therefore, we recannend relief not be granted unless more information can be provided by the licensee to demonstrate this impracticality.
E.
Residual Heat Removal System (RH) 1.
Category C Valves 27 i
a.
Relief Request Specific relief is requested from the quarterly exercising requirements of Section XI for check valves RH-8730A and B, RHR pumps discharge check valves.
Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief These check valves cannot be full stroke tested during unit operation as the shut off head of the pumps is lower than reactor coolant system pressure.
Partial stroke exercising of these check valves will be demonstrated by establishing proper pump discharge flow during periodic pump testing.
Full stroke exercising of this check valve can only be demonstrated during cold shutdown providing the reactor vessel head is removed. This condition is required to establish suction from the RWST and provide system flow i
conditions similar to design injection flow.
Performance of this testing with the reactor coolant system depressurized but intact would not provide adequate surge volume for influx from the RWST to allow the RHR injection system to reach these design flows. The alternative method of
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providing a surge volume by partial draining of the reactor coolant system is not considered a safe practice due to concerns of maintaining adequate water level above the reactor core.
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Evaluation The licensee has shown that full stroke exercising these check valves during power operation can not be accomplished since the only f ull flow flowpath is into the RCS and the low head safety injection pumps are not capable of developing enough l
discharge head to pump into the RCS. These valves will be partial stroke exercised quarterly via the pump recirculation line. However, we feel the licensee has the ability to perform a full flow test on these check valves during cold shutdowns.
While utilizing the RHR System for shutdown cool'ing thets valves will be at least partial stroke exercised and a full stroke might be accomplished depending on the maximum flow obtainable during shutdown cooling as compared to design accident flow. Therefore we feel relief should not be granted from the exercising requirements for these valves until the utility demonstrates that the testing is indeed impractical, b.
Relief Request Specific relief is requested from the Section XI requirements for exercising the following check valves:
RH-8736A and B, low head SIS to hot legs RH-8949A and B, low head SIS to hot legs Code Requirement Refer to valve testing paragraph A.2.
29
Licensee's Basis for Requesting Relief These check valves cannot be tested during unit operation as the shutoff head of the pumps is lower than reactor coolant system pressure. Full stroke exercising of all the branch run check valves can only be demonstrated by total pump discharge during cold shutdown providing the reactor vessel head is removed.
This condition is l
required to establish suction from the RWST and provide system flow conditions similar to design injection flow.
Performance of this testing with the reactor coolant system depressurized but intact would not provide adequate surge volume for influx from the RWST to allow the RHR injection system to reach these design flows. The l
alternative method of providing a surge volume by partial draining of the reactor coolant system is not considered a safe practice due to concerns of maintaining adequate water level above the reactor f
Core.
Evaluation The licensee has shown that exercising these valves during power operation cannot be accomplished since the low head safety injection pumps do not develop sufficient discharge pressure to overcome the RCS pressure holding these check valves shut.
However, we feel the licensee has the ability to perform a flow test on these check valves during cold shutdowns. While utilizing the RHR System for shutdown cooling these valves will be at least partial stroke exercised and a full stroke might be accomplished depending on the 30
maximum flow obtainable during shutdown cooling as compared to design accident flow.
Therefore we feel relief should not be granted from the exercising requirements for these valves until the utility demonstrates that the testing is indeed impractical.
F.
Component Cooling System (CC) 1.
Category B Valves a.
Relief Request Specific relief is requested from quarterly exercising the following valves and an alternate test of full stroke exercising during cold shutdowns when the RCPs are not running and refueling outages is proposed.
CC-9413A and B component cooling to RC pump coolers CC-9414 component cooling return from RC pump coolers CC-9438 component cooling from RC pump coolers CC-685 component cooling from RC pump coolers Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief Component cooling water flow to the reactor coolant pumps is required at all times the pumps are in operation. Failure of one of these valves in a closed position during exercise test would 31
result in a loss of the cooling flow to the pumps.
Exemption is taken to the quarterly exercise test.
The valves will be exercise tested during cold shutdown providing all reactor coolant pumps are not in operation. This testing period will be each refueling outage as a minimum. These valves function as containment isolation valves.
No valve seat leakage is specified as they are supplied with a water seal from the Isolation Valve Seal Water (IVSW) systems.
The operability of the IVSW system is functionally tested as part of this program. These isolation valves are therefore listed as Category B valves.
Evaluation The licensee has demonstrated that exercising these valves when the RCPs are running would result in damage to the Reactor Coolant Pumps which would require plant shutdown. Therefore we feel relief should be granted from exercising canponent cooling valves CC-9413A and B, CC-9414, CC-9438 and CC-685 with the alternate test of full stroke exercising these valves during cold shutdowns when the reactor coolant pumps are not running and refueling outages is satisfactory to ensure these valves perform their intended safety function.
G.
Demineralized Water System (DW) 1.
Category B Valves l
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a.
Relief Request Specific relief is requested from exercising Category A valves DW-0030 and DW-0038, demineralized flushing water to containment.
Code Requirement Refer to valve testing paragraph A.2.
Licensee's Basis for Requesting Relief These manual valves are maintained passively closed during unit operation and are not required to function, other than to provide containment isolation, to safely shut down the reactor or mitigate the consequences of an accident.
Exception is taken to the performance of
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exercising tests as required by IWV-3410.
These valves function as containment isolation valves.
No valve seat leakage is specified as they are supplied with a water seal from the Isolation Valve Seal Water (IVSW) systems. The operability of the IVSW system is functionally tested as part of this program. These isolation valves are therefore listed as Category B valves.
Evaluation We agree with the licensee's basis and therefore feel relief should be granted from the exercising requirements of Section XI for valves DW-0030 and DW-0038. These valves are in their safety related 33
position and are not required to open or close to mitigate the consequences of an accident or safely shutdown the plant. The operability of these valves is inconsequential with regard to the safety function which they perform. We conclude that the quarterly stroke and stroke time measurements are meaningless for passive valves.
H.
Contaimnent Air Sampling System (PR) 1.
Category B Valves a.
Relief Request i
Specific relief is requested from exercising the following Category B valves:
1 PR-0007 PR-0008 PR-0009 PR-0011 PR-0012 PR-0013 Manual isolation valves PR-0015 containment air sampling PR-0016 system.
PR-0017 PR-0019 PR-0020 PR-0021 l
Code Requirement Refer to valve testing paragraph A.2.
34
Licensee's Basis for Requesting Relief These valves function as containment isolation g
valves.
No valve seat leakage is specified as they are supplied with a water seal from the Isolation Valve Seal Water (IVSW) system. The operability of the IVSW system is functionally tested as part of this program.
These isolation valves are therefore listed as Category B valves.
These manual valves are maintained passively closed during unit operation and are not required to function, other than to provide containment isolation, to safely shut down the reactor or mitigate the consequences of an accident.
i Exception is taken to the performance of exercising tests as required by IWV-3410.
Evaluation We agree with the licensee's basis and therefore feel relief should be granted from the exercising and stroke timing requirements of Section XI for the following manual valves:
r PR-0007 PR-0008 PR-0009 PR-0011 PR-0012 PR-0013 i
PR-0015 PR-0016 PR-0017 35
i PR-0019 j
PR-0020 PR-0021 These valves are in their safety related position 1
and are not required to open or close to mitigate j
the consequences of an accident or safely shut down the plant. The operability of these valves is inconsequential with regard to the safety function which they perform. We conclude that the j
quarterly stroke and stroke time measurements are meaningless for passive valves.
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t VI. Attachment I 1
A.
Appendix J Exemption Requests There are no Appendix J exemption requests for Zion Units 1 and 2.
However, the licensee has stated that all containment isolation valves that have Isolation Valve Seal Water supplied to them are categorized B and are not leak tested. This is inconsistent with the present NRC position r
on containment isolation valves.
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V.
Attachment II The following are Category A, B, and C valves that meet the 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 and are full stroke exercised during cold shutdowns and refueling outages.
EG&G has reviewed all valves in this attachment and agrees with the licensee that testing these valves during power operation is not possible due to the valve type and location, system design, or because this action would place the plant in an unsafe condition. We feel these valves should not be exercised during power operation. These valves are listed below and grouped according to the system in which they are located.
A.
Residual Heat Removal System (RH) 1.
RH-8701 and RH-8702, RHR suction from loop A hot leg, cannot be exercised during power operation due to valve interlocks that keep these valves shut when the primary system is at operating pressure. These valves will be full stroke exercised during celd shutdown and refueling outages.
B.
Main Steam System (MS) 1.
MS-0001 MS-0002 Main steam stop valves.
MS-0003 MS-0004 o
38 L
These valves cannot be full stroke exercised during power operation since a turbine trip and subsequent reactor trip would result.
These valtes are part stroke exercised during cold shutdowns and refueling outages.
C.
FW-0016 FW-0017 Main feedwater stop valves.
i FW-0018 i
FW-0019 These valves cannot be exercised during power operation since a turbine trip and subsequent reactor trip would result. These valves are full stroke exercised during cold shutdowns and refueling cutages.
D.
Instrument Air System (IA) 1.
FCV-IA1A and FCV-IA18, Instrument air to valves in containment, cannot be exercised during plant operation since this would isolate valve control air to air operated valves in containment. Loss of control air could cause some safety related valves to go to their fail position and subsequently result in a reactor trip. These valves will be full stroke exercised during cold shutdowns and refueling outages.
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VI. Attachment III The P& ids listed below were used during the course of this review.
System P&ID No.
Revision Main Steam (st-1)
M-20 X
Steam Generator Feedwater M-22 BB Service Water (st-1)
M-32-1 S
Service Water (st-2)
M-32-2 Y
Service Water M-34 U
Condensate Storage M-37-1 H
Containment Spray M-44 Y
Waste Disposal System (st-1)
M-45-1 S
Reactor Coolant M-52 P
t Reactor Coolant M-53 S
Chemical & Volume Control M-54 R
Chemical & Volume Control M-55 U
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Chemical & Volume Control M-56 L
Chemical & Volume Control M-57 M
Residual Heat Removal M-62 R
Safety Injection M-64 T
Safety Injection M-65 Q
Component Cooling M-66 N
Component Cooling M-67 N
I Nuclear Sample M-74-1 J
Penetration & Support Cooling M-93 H
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VII. Attachment IV A.
The following is a list of valves that are never full stroke exercised or that have a testing frequency greater than each refueling outage.
1.
Safety Injection System a.
SI-8948A, B, C and D - accumulator discharge to loops b.
SI-8956A, B, C and D - accumulator outlet check valves 2.
Containment Spray System a.
CS-0016 CS-0021 spray additive check valves to CS-0026 containment spray pumps suctions B.
The following is a list of valves the utility is presently exercising quarterly but by doing so renders an entire safety system inoperable.
1.
SI-8806 -
safety injection pump suction from the RWST 2.
SI-8802.-
safety injection pump common discharge to the cold legs i
3.
SI-8812A & B - low head SIS pump suction from RWST I
C.
Commonwealth Edison / Zion Units 1 & 2 personnel have decided to not include the turbine driven auxiliary feed pump in their IST pump testing program. This is inconsistent with NRC guidelines.
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D.
The following is a listing of relief requests where insufficient technical basis was provided for us to recommend granting relief.
1.
Pump Testing Program I
4 a.
Service water pumps B.1 b.
Component cooling pumps C.1 i
2.
Valve Testine Pronrar.
j t
a.
Safety injection system 1.e b.
Containment spray system 1.a c.
Residual heat cemoval system 1.a & 1.b i
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