3F1089-01, Forwards Response to Generic Ltr 89-04, Guidance on Developing Acceptable Inservice Testing Programs
| ML20248H641 | |
| Person / Time | |
|---|---|
| Site: | Crystal River  |
| Issue date: | 10/03/1989 |
| From: | Widell R FLORIDA POWER CORP. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20248H642 | List: |
| References | |
| 3F1089-01, 3F1089-1, GL-89-04, GL-89-4, NUDOCS 8910110308 | |
| Download: ML20248H641 (23) | |
Text
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Power C O H PO R ATIO N i
October 3, 1989 3F1089-01 U. S. Nuclear Regulatory Commission Attention: Document Control Desk' Washington, D. C. 20555
Subject:
Crystal River Unit 3 Docket No. 50-302 Operating License No. DPR-72 Response to Generic Letter No. 89-04 Guidance on. Developing Acceptable Inservice Testing Programs
Dear Sir:
Please find attached Florida Power Corporation's (FPC) response to Generic Letter 89-04, " Guidance on Developing Acceptable Inservice Testing Programs,"
dated April 3, 1989. The response consists of three attachments which provide the requested information s sociated with FPC's inservice testing program.
Attachment 1 addresses th applicable, alphabetized concerns listed in the Generic Letter under "NRC Guidance on IST Problems and Implementation of IST Program / Revision." Attachment 2 addresses the eleven " Potential Generic Deficiencies" identified in Attachment 1 of GL 89-04, and Attachment 3 is the revised Crystal River Unit 3 Pump and Valve Program (Revision 9).
FPC is confident that the actions we have taken or identified to be performed in the attachments will assure the Crystal River Unit 3 Pump and Valve Program meets the NRC's operational readiness requirements.
Sincerely,
(. /
'Rolf C. Widell, Director Nuclear Operations Site Support RCW/REF/sdw /
Attachments /OA xc Regional Administrator, Region II {t Senior Resident Inspector 8910110308 891003 *#
PDR ADOCK 0500030'2 p PDC POST OFFICE BOX 219
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l ATTACHMENT 1 l
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NRC Guidance on IST Problems and Implementation of IST Procrams/Revisiont A.
Introduction:
No response required.
B. Proarams Current 1v Under NRC Review:
During the review of the Crystal River Unit 3 Pump and Valve Program with respect to Generic letter 89-04, it has been determined that testing as required can be conducted for the components specified and discussed in Attachment I of the Generic Letter. There is no requested relief for an alternative method that requires the review and information established in this part (B) of GL 89-04.
Relief Requests for those components addressed by GL 89-04 have been written or revised to utilize the alternate methods allowed by Attachment 1 of the Generic Letter. They are as follows:
V-030 for Reactor Building Spray Check Valves BSV-26 and BSV-27 V-080 for EFIC Rooms Chilled Water Check Valves CHV-91 and CHV-95 V-120 for Sodium Hydroxide to Reactor Building Spray Pump Suction Check Valves BSV-150 and BSV-151 V-129 for Core Flood Tanks to Reactor Vessel Check Valves CFV-2 and CFV-4 V-150 for Demineralized Water Reactor Building Containment Isolation Check Valve DWV-150 V-160 for Nitrogen Supply to Core Flood Tanks, Reactor Building Isolation Check Valves CFV-17 and CFV-20 V-170 for Makeup supply to Core Flood Tanks, Reactor Building Isolation Check Valves CFV-18 and CFV-19 V-191 for Makeup and Purification (HPI) Pumps' Discharge Check Valves MVV-1, MVV-7 and MUV-11 V-200 for Borated Water Storage Tank to Makeup Pump Suction, Check Valves MVV-60 and MUV-72 V-210 for Rapid-Acting Power Operated Valves V-220 for Main Steam Supply Isolation to Emergency Feedwater Pump Turbine Stop-Check Valves MSV-55 and MSV-56 V-221 for liain Steam Supply Isolation to Emergency Feedwater Pump Turbine Check Valves MSV-186 and MSV-187
p Relief Request V-128 is being withdrawn as a result of the review for GL 89-04.- The Core Flood Tanks to Reactor Vessel Check Valves, CFV-1 and CFV-3, can and will be full-flow tested during Cold Shutdowns.
Additionally, as _part of the overall review of the program, the following modifications have been identified as being required:
- 1. Installation of flow instrumentation for full-stroke exercising of CHV-91, CHV-95 and CHV-202.
- 2. Installation of flow instrumentation for full-stroke exercising of DCV-23 and DCV-24.
- 3. Installation of pressure instrumentation for closure verification of DHV-33 and DHV-36.
- 4. Installation of flow instrumentation for the Makeup and Purification Pumps minimum flow recirculation line.
The above modifications will be completed contingent on receipt of materials no later than March,1991.
C. Proarams With Completed NRC Review:
No response required - Crystal River Unit 3 is not listed in Table 2 of the Generic letter.
D. Proaram Updates / Revisions:
Revision 9 of the Crystal River Unit 3 Pump and Valve Testing Program has been reviewed and modified. The Program has been determined to be in compliance with Generic Letter 89-04, previously submitted and approved relief requests, and/or 10 CFR 50.55 (a) 9 E. Imolementina Procedures:
The Program implementing procedures are presently being reviewed and will be revised to assure complete implementation of the Program by December 29, 1989, with the exception of the following:
Procedures for performing alternate tests on Emergency Feedwater Pumps, EFP-1 and EPF-2 in accordance with Position 9 of GL 89-04 will be revised as appropriate prior to startup from Refuel 7. (See attachment 3, Relief Request #V-111).
Procedures for performing alternate tests on Makeup and Purification !
Pumps, MVP-1A and MVP-1B, and MVP-lC in accordance with Position 9 of GL 89-04 will be revised as appropriate prior to startup from Refuel 7.
(See Attachment 2, response to Position 9).
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e i Procedures for performing full flow tests on the Makeup and Purification
( Valves listed below will be revised, as appropriate, prior to startup from Refuel 7. (See Attachment 3, Relief Requests V-190, V-191, and V-192).
MUV-1 MUV-11 MUV-160 i MUV-2 MUV-36 MUV-161 MUV-6 MUV-37 MVV-163 MUV-7 MUV MVV-164 MVV-10 MUV-43 i
F. Inspection and Enforcement:
No response required - provided for information only.
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ATTACHMENT 2 POTENTIAL GENERIC DEFICIENCIES RELATED TO ,
IST PROGRAMS AND PROCEDURES i 1
- 1. Full Flow Testina of Check Valves j NRC Position: .
'~3 Section XI of the ASME Code requires check velves to be exercised to the positions in which they. perform their safety functions. A check valve's full-stroke to the open position may be verified by passing the maximum l required accident condition flow through the valve. This is considered by. .i the staff as an acceptable full-stroke. Any flow rate less than thic will be considered a partial-stroke exercise. A valid full-stroke exercise by flow requires that the flow through the valve be known. Knowledge of only the total. flow through multiple parallel lines does not provide verification of flow rates through the individual valves and is not a valid full-stroke exercise.
Full flow testing of a check valve as described above may be impractical to perform for certain valves. It may be possible' to qualify other techniques to confirm that the valve is exercised to the position required to perform its safety function. To substantiate the acceptability of any alternative technique for meeting the ASME Code requirements, licensees must as a minimum address and document the following items in the IST program:
- 1. The impracticality of performing a full flow test,
- 2. A description of.the alternative technique used and a summary of the procedures being followed,
- 3. A description of the method and results of the program to qualify the alternative technique for meeting the ASME Code,
- 4. A description of the instrumentation used and the maintenance and calibration of the instrumentation,
- 5. A description of the basis used to verify that the baseline data has been generated when the valve is known to be in good working order, such as recent inspection and maintenance of the valve internals, and
- 6. A description of the basis for the acceptance criteria for the alternative testing and a description of corrective' actions to be taken if the acceptance criteria are not met.
An acceptable alternative to this full-stroke exercising requirement is stated in position 2 below.
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i FPC RESPONSE:
Prior to the issuance of Generic Letter 89-04, FPC's Crystal River Unit 3 (CR-3) Pump and Valve (Inservice Testing) Program was submitted to the NRC for review and approval. This submittal included the majority of the check valves with safety related functions in the open position. As a result of the NRC review, 86 questions on the program were sent to CR-3 by the Staff.
These questions are similar to the positions stated in Generic Letter 89-04.
Some of the questions involved check valves which appeared to have a safety related function in the open direction but were not full flow tested. A review of the Pump and Valve Program was performed to verify the safety function position of all check valves currently existing in the program.
Particular attention was given to those check valves identified in the Staff's questions. In addition, a comprehensive review of all plant systems and cornponents was performed in response to Position 11 of GL 89-04 to ensure that all components important to the safe operation.of the plant are included in the Pump and Valve Program. Any check valves identified by this review as having safety related function in the open direction were added to the program as requiring full flow testing. As a result, two check valves originally scheduled for disassembly and inspection were determined to be capable of full-flow testing and included in that portion of the program. This review also established the need to revise the appropriate procedures to specify the required full flow through the valves.
Attachment 3 of this letter is the revised Pump and Valve Program (Revision 9). The intent of Generic Letter 89-04 Position 1 is considered to be met by submittal of the revised program.
- 2. Alternative to Full Flow Testina of Check Valves NRC Position:
The most common method to full-stroke exercise a check valve open (where disk position is not observable) is to pass the maximum required accident flow through the valve. However, for some check valves, licensees cannot I practically establish or verify sufficient flow to full-stroke exercise the valves open. Some examples of such valves are, in PWRs, the containment spray header check valves and combined LPSI and safety injection accumulator i header check valves and, in BWRs, the HPCI or RCIC check valves in the pump suction from the suppression pool. In most commercial facilities, establishing design accident flow through these valves for testing could result in damage to major plant equipment. "
l The NRC staff position is that valve disassembly and inspection can be used )
as a positive means of determining that a valve's disk will full-stroke l exercise open or of verifying closure capability, as permitted by IWV-3522.
If possible, partial valve stroking quarterly or during cold shutdowns, or after reassembly must be performed.
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The staff has established the following positions regarding testing check valves by disassembly:
- a. During vaive testing by disassembly, the valve internals should be visually. Inspected for worn or corroded parts, and the valve disk should be manually exercised.
- b. Due to the scope of this testing, the personnel. hazards involved and i
system operating restrictions, valve disassembly and inspection may l
be performed during reactor refueling outages. Since this frequency differs from the : Code required frequency, this deviation must be specifically noted in the IST program.
- c. Where the licensee determines that it is burdensome to disassemble and inspect all applicable valves . each refueling outage, a sample disassembly and inspection plan for groups of identical valves in similar applications may be employed. The NRC guidelines for this plan are explained below:
The sample disassembly and inspection program involves grouping similar valves and testing one valve in each group during'each refueling outage. The sampling technique requires that each valve in the group be the same design (manufacturer, size, model number, and materials of construction) and have.the same service conditions including valve orientation. Additionally, at each
' disassembly the licensee must verify that the disassembled valve is capable of full-stroking and that the internals of the valve are structurally sound (no loose or corroded parts). Also, if the disassembly is to verify the full-stroke capability of the valve, the disk should be manually exercised.
A different valve of each group is required to be disassembled, inspected, and manually full-stroke exercised at each successive refueling outage, until the entire group has been tested. If the disassembled valve is not capable of being full-stroke exercised or there is binding or failure of valve internals, the remaining valves in that group must also be disassembled, inspected, and manually full-stroke exercised during the same outage. Once this is completed, the sequence of disassembly must be repeated unless extension of the interval can be justified.
Extending the valve sample disassembly and inspection interval from disassembly of one valve' in the group every refueling outage or expanding the group size would increase the time between testing of any particular valve in the group. With four valves in a group and an .18-month reactor cycle, each valve would be disassembled and inspected every six years. If the fuel cycle is increased to 24 months, each valve in a four-valve sample group would be disassembled and inspected only once every 8 years.
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Inspection of the valve disassembly / inspection interval from that l allowed by the Code (quarterly or cold shutdown frequency) to longer than once every 6 years is a substantial change which may not be justified by the valve failure rate data for all valve groupings.
When disassembly / inspection data for a valve group show a greater than 25% failure rate, the licensee should determine whether the group size should be decreased or whether more valves from the group should be disassembled during every refueling outage.
Extension of the valve disassembly / inspection interval to one valve l every other refueling outage or expansion of the group size above four valves should only be considered in cases of g_xtreme hardship where the extension is supported by actual in-plant data from previous testing. In order to support extension of the valve disassembly / inspection intervals to longer than once every 6 years, licensees should develop the following information:
- a. Disassemble and inspect each valve in the valve grouping and document in detail the condition of each valve and the valve's capability to be full-stroked.
- b. A review of industry experience, for example, as documented in NPRDS, regarding the same type of valve used in similar service.
- c. A review of the installation of each valve addressing the "EPRI Applications Guidelines for Check Valves in Nuclear Power Plants" for problematic locations.
FPC Response:
Prior to the issuance of Generic letter 89-04, the Pump and Valve Program submitted for review by FPC had identified ten (10) valves for disassembly and inspection as an alternative to full flow testing. A review of the program, with respect to Position 1 and Position 3 of GL 89-04 and the 86 questions posed by the NRC staff, was performed to ensure that disassembly and inspection is the only possible means of testing these valves.
A review of the ten existing valves to be disassembled and inspected confirmed this was the only possible means of verifying full flow with the exception of two valves, (CFV-1 and CFV-3). These valves will now be full flow tested at cold shutdown.
l A review of - the safety function of all check valves as well a: a comprehensive review of the program (for Position 11 of the Generic Letter) revealed a number of check valves as having a safety function in the closed position. Those that could not be back flow tested in accordance with Position 3 of..this letter (and Section XI, paragraph IWV-3520 of the ASME Code) are identified by relief request to be disassembled and inspected to verify closure. This is consistent with Position 2 of Generic Letter 89-04 '. A total of nine (9) valves have been added to the disassembly and inspection program to verify closure. These valves are -identified in Attachment 3 (Pump and Valve Program) in Relief Requests V-080, V-191, V-220, and V-221.
- 3. Back Flow Testino of Check Valves NRC Position:
Section XI requires that Category C check valves (valves that are self actuated in response to a system characteristic) performing a safety function in the closed position to prevent reversed flow be tested in a manner that proves that the disk travels to the seat promptly on cessation or. reversal of flow. In-addition, for category A/C check valves (valves that have a specified leak rate limit and are self actuated in response to-a system characteristic), seat leakage must be limited to a specific maximum amount in the closed position for fulfillment of their function.
Verification that a Category C valve is in the closed position can be done by visual observation, by an electrical signal initiated by a position-indicating device, by observation of appropriate pressure indication in the system, by leak testing, or by other positive means.
Examples of ASME Code Class check valves that perform a safety function in the closed position that are frequently not back flow tested are:
- a. main feedwater header check valves
- b. pump discharge check valves on parallel pumps l c. keep full check valves
- d. check valves in steam supply lines to turbine driven AFW pumps
- e. main steam non-return valves
- f. CVCS volume control tank outlet check valves.
FPC Response:
As a result of the review described in FPC's response to Position 1, a number of back flow tests were added to the program. Those that could not be back flow tested are identified to be disassembled and inspected as described in FPC's response to Position 2 of the Generic Letter.
The revised Pump and Valve Program (Attachment 3) meets the intent of Generic Letter 89-04, Position 3.
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4-. Pressure' Isolation Valves NRC Position:
- a. General Pressure isolation valves (PIVs) are defined as two normally closed valves;in series that isolate the reactor coolant' system (RCS) from an attached low pressure' system. PIVs are, located at all RCS low pressure system interfaces. The 10 CFR 50.2 contains the definition.
of the'RCPB. PIVs are within the reactor coolant pressure boundary-(RCPB).
l' The following summary is based upon the staff's review of responses to Generic Letter 87-06, Periodic Verification of Leak Tight Integrity of Pressure Isolation. Valves. All plants licensed since 1979 have a i full list of PIVs in the plant Technical Specifications (TS) along with leak test requirements and limiting conditions for operation (LCOs).
The plants licensed prior to 1979 fall into several categories. Some pre-1979 plants have a full list of PIVs along with leak test ~
requirements and LCOs in the plant TS. Some pre-1979 plants have only .
Event V PIVs (see below)'in the plant TS. Some pre-1979 plants have no TS requirements regarding PIVs.
All PIVs, listed in plant TS should be listed in the IST program as Category A or A/C valves. The TS requirements should be referenced in the IST program.
'b. Event V PIVs Event V PIVs are defined as two .c_he_c_k valves in series at a low pressure /RCS interface whose failure may result in a LOCA that bypasses containment. Event V refers to the scenario described for this event in the WASH-1400 study.
On April 20, 1981, the NRC issued an Order to 32 PWRs and 2 BWRs which required that these licensees conduct _ leak rate testing of their PIVs, based 'on plant-specific NRC supplied lists of PIVs, and required licensees to modify their TS accordingly. These orders are known as the " Event V Orders" and the valves listed therein are the " Event V" PIVs. The Event V PIVs are a subset of PIVs.
Based upon the results of recent inspect %ns, it has been determined that the following implementation problem still exists with respect to testing of PIVs. The staff has determined that in some cases the procedures are inadequate to arsure that these valves are individually leak tested and evaluated against the leakage limits specified in the TS; in other cases, the procedures were adequate but were not being g followed. Specifically, some check valves were tested in series as opposed to individually and some check valves were not tested when required.
Licensees should review their testing procedures to ensure the Event V PIVs are individually leak rate tested.
FPC Response:
Crystal River Unit-3 is a pre-1979 licensed plant with only the Event V PIVs (CFV-1, CFV-3, DHV-1 and DHV-2) listed in the plant Technical Specifications (TS) (Sections 3.4.6.2 and 4.4.6.2.2, and Table 3.4-2). These four (4)
Event V PIVs are identified in the Pump and Valve Program as Category "A/C",
cross referenced to the appropriate TS requirement (Section 4.4.6.2.2),
cross referenced to the appropriate surveillance procedure (SP-603) utilized for their testing, and noted as PIV's in the remarks column. SP-603 " Decay Heat / Core Flood Check Valve Leak Testing", assures that the referenced PIVs are individually leak tested and evaluated against the leakage limits specified in the TS.
- 5. Limitina Values of Full-Stroke Times for Power Operated Valves NRC Position:
The code intent with respect to measuring the full-stroke times of power operated valves is to verify operability and to detect valve degradation.
Measurement of full stroke times for air operating valves fulfills this intent. However, reviews of operating experience have identified several problems with motor operated valves (MOVs) including limitations with strob time as a measure of operational readiness of the MOV. As a result, the industry has made extensive efforts to improve the knowledge and understanding of operational characteristics of motor operated valves. This effort has been conducted by industry groups (NUMARC, INPO, NMAC, EPRI),
individual licensees, equipment vendors, and national standards groups.
We believe the information and knowledge developed by these groups should be reviewed and utilized. Some of the information publicly available includes an INP0 white paper titled, " Motor-Operated Valvi Performance Update", issued October 4,1988. This document icentifies MOV problem areas and provides the key elements for a comprehensive MOV program. Another document is the " Technical Repair Guidelines for the Limitorque Model SMB-000 Valve Actuator", issued by the Nuclear Maintenance Application Center (NMAC) in January, 1989. This guide addresses several areas such as setting torque and limit switches, prevention maintenance, actuator failure modes, failure analysis to determine root cause and corrective action, and pre-operational and post-maintenance testing.
NRC staff concerns regarding MOV operability led to the issuance of Bulletin 85-03 and Bulletin 85-03, Supplement 1. Expansion of this bulletin in the form of a generic letter is being considered by the NRC. ,
In spite of the limitations of stroke time testing of MOVs, IWV-3413(a) of the ASME Code requires that the licensee specify the limiting value of full-stroke time of each power operated valve. The corrective actions of IWV-3417(b) must be followed when these limiting values are exceeded. The Code does not provide any requirements or guidelines for establishing these limits nor does it identify the relationship that should exist between these limits and any limits identified for the relevant valves in the plant TS or safety analysis.
The purpose of the limiting value of full-stroke time is to establish a value for taking corrective action on a degraded valve before the valve reaches the point where there is a high probability of failure to perform its safety function if called upon. The NRC has, therefore, established the guidelines described below regarding limiting values of full-stroke time for power operated valves.
The limiting value of full-stroke time should be based on the valve reference or average stroke time of a valve when it is known to be in good condition and operating properly. The limiting value should be a reasonable deviation from this reference stroke time based on the VAe size, valve type, and actuator tjpe. The deviation should not be so restrictiw that it results in a valve being declared inoperable due to reasonable stroke time variations. However, the deviation used to establish the limit should be such that corrective action would be taken for a valve that may not perform its intended function.
When the TS or safety analysis limit for a valve is less than the value established using the above guidelines, the TS or safety analysis limit should be used as the limiting value of full-stroke time.
When the TS or safety analysis limit for a valve is greater than the value established using the above guidelines, the limiting value of full-stroke time should be based on the above guidelines instead of the TS or safety analysis limit.
FPC Response:
ASME B&PV Section XI, IWV-3413(A), requires that the licensee specify the limiting value of full-stroke time of each power operated valve. If the specified limiting value is exceeded the corrective actions of IWV-3417(b) must be followed. As stated in Generic Letter 89-04, the purpose of the ,
'imiting value of full-stroke time is to establish a value for taking orrective action on a degraded valve before the valve reaches the point vnere there is a high probability of failure to perform its safety function.
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In order for the limiting value of full-stroke time to be effective it must be based on a. reference stroke time of a valve when it is known to be in good condition and operating properly. ~ To provide a benchmark that does not permit a slow steady change in valve performance, the guidelines set L forth in the 0&M Pump and Valve Standards (Part 6 and Part 10) were used as the basis for establishing the limiting values of full-stroke for the Crystal River Unit 3 IST Program. These new standards are referenced in the 1988 Addendum of Section XI and replace subsection IWP and IWV of that
, code. The reference. values for power operated valves are listed in the implementing exercise procedures and reflect the stroke times of the valves when they are known to be .in good condition and operating properly.
Florida Power Corporation completed an engineering study on April 16, 1988 which identified the correct response time for ES functions. The value of .
full-stroke time for each power operated valve was determined by taking the lesser of twice the reference value, or the required response time to support ES function as stated in the FSAR or Technical Specifications.
In addition, an alert value is established using the chart provided below.
If the alert value is greater than the limiting value of full-stroke time,
.an alert value is not specified. Since the reference value is established with the valve operating acceptably, each stroke test should be compared '
to this reference value.
.The O&M Pump and Valve Standards, Part 10 approach meets or. exceeds the provisions of ASME Section XI, paragraph 3417(a), and therefore meets the intent of Position 5 of Generic Letter 89-04.
ACTUATOR TYPE REFERENCE VALUE RANGE
$ 2.0 Sec. 2.0 Sec. > RV s 10.0 Sec. > 10.0 Sec.
MOTOR and S0LEN0ID 2.0 Sec. +/- 25% +/-15%
AIR and HYDRAULIC 2.0 Sec. +/-50% +/-25%
- 6. Stroke Time Measurements for Rapid-Actina Valves 1
NRC Position:
The Code requires the following for power operated valves with stroke times 10-seconds or less: (a) Limiting values of full-stroke times shall be specified [IWV-3413(a)], (b) Valve stroke times shall be measured to (at least) the nearest second [IWV-3413(b)] and (c) if the stroke time increases by 50% or more from the previous test, then the test frequency shall be increased to once each month until corrective action is taken [IWV-3417(a)].
Paragraph IWV-3417(b) specifies corrective actions that must be taken.
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1 With reference to (c) above, measuring changes in stroke times from a reference value as opposed to measuring changes from the previous test is l an acceptable (and possibly better) alternative to the staff. However, since this is different from the Code requirement, this deviation should be documented in the IST program.
Most plants have many power operated valves that are capable of stroking in 2 seconds or less such as small solenoid operated valves. Licensees encounter difficulty in applying the Code 50% increase of stroke time corrective action requirements for these valves. The purpose of this requirement is to detect and evaluate degradation of a valve. For valves with stroke times in this range, mLch of the difference in stroke times from test to test comes from inconsistencies in the operator or timing device used to gather the data. These differences are compounded by rounding the results as allowed by Code. Thus, the results may not be representative of actual valve degradation.
The following discussion illustrates the problem that may exist when complying with the Code requirements for many of these rapid-acting valves:
A valve may have a stroke time of 1.49 seconds during one test and a stroke time during the following test of 1.51 seconds. If stroke times are rounded to the nearest second as allowed by the Code, the difference between these tests would exceed the 50% criteria and would require an increased frequency of testing until corrective action is taken. This can result from a stroke time difference of 0.02 seconds, which is usually not indicative of significant valve degradation.
Power operated valves with normal stroke times of 2 seconds or less are referred to by the staff as " rapid-acting valves". Relief may be granted from the requirements of Section XI, Paragraph IWV-3417(a) for these valves provided the licensee assigns a maximum limiting value of full-stroke time of 2 seconds to these valves and, upon exceeding this limit, declares the valve inoperable and takes corrective action in accordance with IWV-3417(b).
An acceptable alternative to the Code stroke timing requirements is the .
above stated rapid-acting valve position. Since this represents a deviation I from the Code requirements, it should be specifically documented in the IST program.
FPC Response:
For power operated valves with stroke times >2 seconds to 110 seconds, the following Code requirements as stated in the Staff position will be met.
a) Limiting values of full-stroke times will be specified [IWV-3413(a)];
b) Valve stroke times will be measured to (at least) the nearest second
[IWV-3413(b)]; and c) If the stroke time increases by 50% or more from a reference value, then the test frequency will be increased to once each month until corrective action is taken [IWV-3417(a)].
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The above items have been addressed in the Crystal River Unit 3 Pump and Valve Program, and as appropriate in tne implementing procedures. j Florida Power Corporation is also in agreement with the Nuclear Regulatory Commission staff's position, which is an alternative to the Code, relative to " rapid-acting valves." We have therefore revised the Pump and Valve Program,.Section 8.5, to state:
1 ET-002 -
Represents a rapid-acting valve with a limiting value of l stroke-time of 2.0 seconds. (All other power-operated valves have their respective limiting value of stroke-time I identified in the implementing procedures, since these values i are subject to change based on post ' maintenance reference conditions).
- 7. Iestino Individual control Rod Scram Valves in Boilina Water Reactors (BWRs)
NRC Position:
BWRs are equipped with bottom-entry hydraulically driven control rod drive mechanisms with high-pressure water providing the hydraulic power. Each control rod is operated by a hydraulic control unit (HCU), which consists of valves and an accumulator. The HCU is supplied charging and cooling water from the control rod drive pumps, and the control rod operating cylinder exhausts to the scram discharge volume. Various valves in the control rod drive system perform an active function in scramming the control rods to rapidly shut down the reactor.
The NRC has determined that those ASME Code Class valves that must change position to provide the scram function should be included in the IST program and be tested in accordance with the requirements of Section XI except where relief has been granted in a previously issued Safety Evaluation Report or as discussed below.
The control rod drive system valves that perform an active safety function in scramming the reactor are the scram discharge volume vent and drain valves, the scram inlet and outlet valves, the scram discharge header check valves, the charging water header check valves, and the cooling water header check valves. With the exception of the scram discharge volume vent and drain valves, exercising the other valves quarterly during power operations could result in the rapid insertion of one or more control rods more frequently than desired. j Licensees should test these control rod drive system valves at the Code-specified frequency if they can be practically tested at that frequency.
However, for those control rod drive system valves where testing could result in the rapid insertion of one or more control rods, the rod scram test frequency identified in the facility TS may be used as the valve testing frequency to minimize rapid reactivity transients and wear of the control rod drive mechanisms. This alternate test frequency should be clearly stated and documented in the IST program.
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- Industry experience has shown that normal control rod motion may verify
~ the cooling water header check valve moving to its safety function position.
This can be demonstrated because rod motion itay not occur if this check valve were to fail in the open position. If this test method is used at the Code required frequency, the licensee should clearly explain in the IST
. program that this is how these valves are being verified to close quarterly.
Closure verification of the charging water header check valves requires that the control rod drive pumps be stopped to depressurize the charging water-header. This test .should not be performed during power operation because stopping the pumps result in loss.of cooling water to all control rod drive mechanisms and seal damage could result. Additionally, this test cannot be performed during each cold shutdown because the control rod drive pumps supply seal water to the reactor recirculation pumps and one of the recirculation pumps is usually kept running. Therefore, the HCU accumulator pressure decay test as identified in the facility TS may be used as the charging water header check valve alternate testing frequency for the reasons stated above. If this test is not addressed in the licensee's TS this closure verification should be performed at least during each refueling outage, and this alternate test frequency should be specifically documented in the IST program. <
The scram inlet and outlet valves are power operated valves that full-stroke in milliseconds and are not equipped with indication for both positions, therefore, measuring their full-stroke time as required by the Code may be
' impractical. Verifying that the associated control rod meets the scram insertion _ time limits defined in the plant TS can be an acceptable alternate method of detecting degradation of these valves. Also, trending the stroke-times of these valves may be impractical and unnecessary since they are indirectly stroke timed and no meaningful correlation between the scram time and valve stroke time may be obtained, and furthermore, conservative limits are placed on the control rod scram insertion times. If the above test is used to verify the operability of scram inlet and outlet valves, it should be.specifically documented in the IST program.
FPC Response:
Not Applicable - Crystal River Unit 3 is a Pressurized Water Reactor a
- 8. Startino Point for Time Period in TS ACTION Statements NRC Position:
ASME Section XI, IWP-3220, states "All test data shall be analyzed within 96 hours0.00111 days <br />0.0267 hours <br />1.587302e-4 weeks <br />3.6528e-5 months <br /> after completion of a test". IWP-3230(c) states. in part, "if -
.- the deviations fall within the ' Required Action Range' of Table IWP-3100-2, the pump shall be declared inoperative ....".
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In many cases pumps or valves covered by 'ASME,Section XI, Subsections IWP and IWV, are also in systems covered by TS and, if declared inoperable, would result in the plant entering an ACTION statement. These ACTION statements generally have a time period after which, if the equipment is still inoperab1( 4 the plant is required to undergo some specific action such as commence plant shutdown.
The potential exists for a conflict between the aforementioned data analysis interval versus the TS ACTION statement time period.Section XI, IWP-6000 requires the reference values, limits, and acceptance criteria - to be included in the test plans or records. of tests. With this information available, the shift individual (s) responsible for conducting the test (i.e., shift supervisor, reactor operator) should be able to make a timely determination as to whether or not the data meets the requirements.
When the data is determined to be within the " Required Action Range" of Table IWP-3100-2 the pump is inoperable and the TS ACTION statement time starts. The provisions in IWP-3230(d) to recalibrates the instruments involved and rerun the test to show the pump is still capable of fulfilling its function are an alternative to replacement or repair, not an additional action that can be taken before declaring the pump inoperable.
The above position, which has been stated in terms of pump testing, is equally valid for valve testing.
In summary, it is the staff's position that as soon as the data is recognized as being within the " Required Action Range" for pumps or exceeding the limiting value of full-stroke time for valves, the associated component must be declared inoperable and the TS ACTION time must be started.
FPC Response:
Florida Power Corporation is in agreement with the Staff's position relative to the starting point for time periods in TS ACTION statements.
As soon as test data is compared to proceduralized acceptance criteria and recognized as being within the " Required Action Range" for pumps or exceeding the limiting valve of full-stroke time for valves, the associated component will be declared inoperable and the TS ACTION statement time must be started.
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- 9. Pumo Testina Usin'a Minimum-flow Return Line With or Without Flow Measurina Device NRC Position:
An inservice. pump test requires that the pump parameters shown in Table IWP-3100-1 be measured and evaluated to determine pump condition and detect degradation. Pump differential pressure and flow rate are two parameters that are measured and evaluated together to determine pump hydraulic performance. !
Certain safety-related systems are designed such that the minimum-flow return lines are the only flow paths that can be utilized. for quarterly pump testing. Furthermore, some of these systems, do not have any flow path that can be utilized for pump testing during any plant operating mode except the mininum-flow return lines. In these cases, pumping through the !
path designed' for fulfilling the intended system safety function could !
result in damage to plant equipment. Minimum-flow lines are not designed for pump testing purposes and few have installed flow measuring devices.
In cases where flow can only be established through non-instrumented minimum-flow path during quarterly pump testing and a path exists at cold shutdowns or refueling outages to perform a test of the pump under full or substantial flow conditions, the staff has determined that the increased interval is an acceptable alternative to the Code requirements provided that pump differential pressure, flow rate, and bearing vibration measurements are taken during this testing and that quarterly testing also measuring at least pump differential pressure and vibration is continued. Data from both of these testing frequencies should be trended as required by IWP-6000.
Since the above position is a deviation from the Code required testing, it should be documented in the IST program.
In cases where only the minimum-flow return line is available for pump testing, regardless of the test interval, the staff's position is that flow instrumentation which meets the requirements of IWP-4110 and 4120 must be installed in the mini-flow return line. Installation of this instrumentation is necessary to provide flow rate measurements during pump testing so this data can be evaluated with the measured pump differential pressure to monitor for pump hydraulic degradation.
NRC Bulletin 88-04, dated May 5,1988, advised licensees of the potential for pump damage while running pumps in the minimum-flow condition. The above guidelines for meeting the Code or performing alternative testing is not intended to supersede the thrust of this Bulletin. Licensees should ensure that if pumps are tested in the low flow condition, the flow is sufficient to prevent damage to the pump.
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FPC Response: i l
- Crystal River Unit 3 has five (5) pumps in the Pump and Valve Program for j
'Section XI that have at least'a portion of their test loop flowing through a minimum flow recirculation line. These include Emergency Feedwater Pumps ,
EFP-1 and EFP-2, and Makeup and Purification (High Pressure Injection) Pumps MVP-1A, MVP-1B, and MVP-10.
EFP-1 and EFP-2 are tested on a quarterly basis with the total flow directed through the recirculation line back to the dedicated Emergency Feedwater
. Tank (EFT-2). Relief Request V-111 to the Pump and Valve Program provides for an alternate method for testing which will be conducted during refueling outages, beginning with Refuel 7.
MVP-1A, MVP-1B, and MVP-1C are tested with three (3) flow paths established during the test. Two (2) of the three (3) flow paths contain flow measuring instruments, while the third is the minimum flow recirculation line back-to the Makeup Tank (MUT-1). An engineering evaluation is being conducted to determine the feasibility of the installation of flow measuring instrumentation into the recirculation line in order to provide complete flow measurement on a quarterly basis. Additionally, whether flow instrumentation is installed or not, a complete inservice test will be
. performed on each makeup pump, during startup from each refuel outage, beginning with Refuel 7. 'This will be accomplished by injecting approximately 500 gpm into the Reactor Coolant System while the plant is in operational Mode 3.
- 10. Containment Isolation Valve Testina NRC Position:
All containment isolation valves (CIVs) that are included in the Appendix J, program should be included in the IST program as Category A or A/C valves. The staff has determined that the leak test procedures and requirements for containment isolation valves specified in 10 CFR 50, Appendix'J are equivalent to the requirements of IWV-3421 through 3425.
However, the licensee must comply with the Analysis of Leakage Rates and Corrective Action. requirements of Paragraph IWV-3426 and 3427(a).
L IWV-3427(b) specifies additional requirements on increased test frequencies i for valve sizes of six inches and larger and repairs or replacement over the requirements of IWV-3427(a). Based on input from many utilities and staff review of testing data at some plants, the usefulness of IWV-3427(b) does not justify the burden of complying with this requirement. Since this position represents a deviation from the Code requirements, it 'should be documented in the IST program.
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FPC Response: !
All Appendix J, Type C valves installed in systems at Crystal River Unit i 3 are presently categorized in the Pump and Valve Program as "A" or "A/C".
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Florida Power Corporation concurs with the Nuclear Regulatory Commission Staff's position relating the procedural intent and requirements of 10CFR50, Appendix J (for Type C testing) and the ASME Section XI leak rate testing requirements of Paragraphs IWV-3421 through IWV-3425. FPC also complies with the Analysis of Leakage Rates and Corrective Action requirements or Paragraph lWV-3426 and 3427(a). In accordance with Paragraph IWV-3426, acceptable leakage rates have been determined by Florida Power Corporation.
FPC also concurs with the NRC Staff's position that the usefulness of IWV-3427(b) does not justify the burden of complying with this requirement.
Therefore, the Pump and Valve Program, Section 5.0, " Valve Program Instructions," has been revised to document this deviation in the Code, as required by Generic Letter 89-04, Position 10.
- 11. IST Procram Scope NRC Position:
The 10 CFR 50.55d requires that inservice testing be performed on certain ASME Code Class 1, 2, and 3 pumps and valves.Section XI, Subsections IWP-1100 and IWV-1100, define the scope of pumps and valves to be tested in terms of plant shutdowns and accident mitigation. The plant's FSAR (or equivalent) provides definitions of the necessary equipment to meet these functions. The staff has noted during past IST program reviews and inspections that licensees do not always include the necessary equipment '
in their IST programs. Licensees should review their IST programs to ensure adequate scope. Examples that are frequently erroneously omitted from IST programs are:
- b. control room chilled water system pumps and valves,
- c. accumulator motor operated isolation valves, or accumulator vent valves, i
- d. auxiliary pressurizer spray system valves, ,
- e. boric acid transfer pumps, l
- f. valves in emergency boration flow path,
- g. control valves that have a required fail-safe position,
- h. valves in mini-flow lines.
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It should be recognized that the above examples of pumps and valves do not-meet the' IWP and IWV scope statement requirements for all plants.
l The intent of 10 CFR 50 Appendix A, GDC-1, and Appendix B,- Criterion XI, is that all components, such as pumps and valves, necessary for safe operation are to be tested to demonstrate that they will perform satisfactorily in service. Therefore, while 10 CFR 50.55a delineates the testing requirements for ASME Code Class 1, 2, and 3 pumps and valves, the testing of pumps and valves is not to be limited to only those covered by 10 CFR 50.55a.
FPC Response:
A review- of the CR-3 Pump and Valve (Inservice Testing) Program was performed to en ure all pumps and valves "necessary for safe operation" of
-the plant are included. Particular attention was given to the examples listed in Position 11 of Generic Letter 89-04. :
The first part of the review involved a thorough check of the flow diagrams for the systems in the IST program. The flow diagrams were compared to the tables in the Pump and Valve Program to ensure all class 1, 2, and 3 components in the systems were included in the program. The system flow diagrams were then reviewed to determine if any interfacing components could affect the safety function of the system. ,
The second part of the review for Position 11 focused on documents outside of the Pump and Valve Program. The FSAR and Design Basis Documents were reviewed for additional components that are important to the safe operation of the plant and may not have been included in the IST Program. The safety list classification and configuration data base were searched for any system i not included in the IST Program and those pumps and valves that are !
classified 'as safety related. As a result of this review, all components necessary.for safe operation of the plant were found to be included in the !
CR-3 Pump and Valve Program.
The specific examples listed in Position 11 of Generic Letter 89-04 are' l included in the program with the exception of; 1) BWR Scram System Valves l (not applicable), 2) Auxiliary pressurizer spray system valves, and 3) boric acid transfer pumps (and associated trains).
The auxiliary pressurizer spray line is not required to operate during power or emergency operations. This line is only used during normal cooldown of the plant, as stated in the CR-3 FSAR, chapter 9.4. During power operation, this line is isolated by an upstream power operated valve (which is the safety class pipe break), and upstream of that is a containment ,
isolation check valve. With the exception of the containment isolation check valve, the valves in this line are exempt from Section XI testing. j i
i The boric acid transfer pumps and their associated trains are not required for emergency operation. . Presently, CR-3 Technical Specifications' require these trains to be operable during MODES 1-4, however this requirement has been requested to be removed from the Technical Specification in the ongoing.
Technical Specification Improvement Program. The basis for this change is the~ B&W Owners Group Technical Specification Committee document,
" Application of Selection Criteria To The B&W Standard Technical Specifications" (47-1170689-00) . This document states, " Normal RCS boration is needed to help maintain shutdown margin during both power operation'and shutdown. The concentrated. boric acid storage tank is not assumed operable and is not required for mitigation of a DBA."
The borated water storage tank (BWST) is the emergency boration supply via the Emergency Core Cooling _ System (ECCS). Technical Specification surveillance and Section XI testing will continue on the BWST support of the ECCS. Technical Specification surveillance of the Boric Acid Storage
~ Tank and boration capability during- normal operation will also continue until the revised Techaical Specifications are approved. This will not be included in the IST program since it is not considered to have a safety.
function.
The newly revised CR-3 Pump and Valve Program (see Attachment 3) has been reviewed as outlined above and meets the intont of Generic Letter 89-04, Position 11 and ASME Section XI, subparagraphs IWP and IWV.
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ATTACHMENT 3 PUMP AND VALVE TESTING PROGRAM Attachment 3 is Revision 9 to the Crystal River' Unit 3 Pump and Valve Program.
In the past, a single annual update of the Program was provided to the NRC in accordance with the administrative controls established in the Program. From this date on, each revision to the Pump and Valve Program will be submitted to the NRC within 30 days of implementation, eliminating.the annual update process.
The last annual update submitted to the NRC consisted of revisions .up to and including Revision 7. Since that time, Revision 8 has been issued-in-house..
In generating a new control process, FPC is reissuing the entire Pump and Valve Program with all pages identified as Revision 9 but only noting text changes (by vertical bars) from Revision 8.
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