ML20248G685
| ML20248G685 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 09/26/1989 |
| From: | Kuncl L NEBRASKA PUBLIC POWER DISTRICT |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CNSS897527, GL-89-04, GL-89-4, NUDOCS 8910100339 | |
| Download: ML20248G685 (11) | |
Text
_ _ _ _
H'
(,,
h COOPER NUCLEAR STATION fg/
_ Nebraska Public Power District
"" " "'A*c"e "o"JEl&^>'?" "'"
CNSS897527 September 26, 1989 U.S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555
Subject:
Submittal of Confirmatory Letter in Response ta NFC Generic Letter 89-04.
Cooper Nuclear Station, NRC Docket No. 50-298/
Reference 1:
NRC Generic Letter No.
89-04, " Guidance on Developing Acceptable Inservice Testing Programs".
Gentlemen:
Reference I requested the District to:
1.
Review their most recently submitted IST programs and implementing procedures against the positfons delineated in Attachment 1.
2.
Withia six months of the U.te of this Jetter, confi.~a in writing their conformance with the stated positions.
In cases where conf ormance with the stated positions would result in equipment modification, the licensee should provide in his conformation letter a schedule for completing the required modifications.
The District has completed its evaluation of the Cooper Nuclear Station IST Program and implementing procedures with respect to compliance with the positions delineated in Reference 1. to this letter contains the District's response.
As a result of this evaluation, the District will upgrade the Cooper Nuclear Station IST Program in accordance with the follow-ing schedule:
A revised IST Program Plan is under development and, pending review and approval, it will be submitted to the NRC no later than May 1990.
As a result of evaluations done in response to the generic letter j
and those yet to be completed, it is estimated that greater than 60%
1 of the existing Cooper Nuclear Station IST Program related surveil-l lance tes'c procedures will require revision and several additional (new) procedures will be developed.
Based on current projections, j
revised testing procedures reflecting the requirements of the
)
positions outlined in the generic letter will be implemented such j
l that any testing performed af ter June 1990 will conform to the j
specified requirements.
g
'}(d,N{_ ___
- 910100339 090926 i
l PDR ADOCK 05000298 P
PNV
f. -
U.S. Nuclear R gulatory Commission S:ptemb:r 26, 1989 Page 2 The schedule for tests required to be performed during a refueling l
outage will be initiated during the forthcoming refueling outage scheduled to commence in March 1990.
The acceptance criteria for the limiting values of full-stroke times for all power-operated valves in the program that require stroke time measurements will be reviewed per Position 5 and the implement-ing test procedures will be revised, as required, such that any testing performed after June 1990 will conform to the specified requirements.
Administrative directives will be in place to implement the require-ment for immediately declaring components inoperable when IST limits are exceeded as specified in Position 9 no later than January, 1990.
The testing requirements of the revised program will be fully implemented by June 1990.
Please-contact E. M. Mace, Engineering Manager, Cooper Nucicar Station, if additional information regarding this matter is required.
Sincerely, L.
A L. G. Kuncl Fucient Power Group Manager LGK:sa Attachment cc:
U.S. Nuclear Regulatory Commission Regional Office, Region IV NRC Resident Inspector Cooper Nuclear Station
f
,U.S. Nudlear Regulatory Lommission September 26, 1989 Page.3 STATE OF NEBRASKA)
)ss PLATTE COUNTY
)
-L. G. Kuncl, being first duly sworn, deposes and says that he is an authorized representative of the Nebraska Public Power District, a public corporation and political subdivision of the State of Nebraska; that he is duly authorized to submit this response on behalf of Nebraska Public Power District; and that the statements contained herein are true to the best of his knowledge and belief.
L.IG. Kuncl Subspribed in my presence and sworn to before me this df day of-
,'Alaflo>, /V xJ 1989.
o' GEkA4L 80 testa oflierasta UL JANIE TgMg
""' I
(/
NOTARY PUBLIC
---s
---_------------,------------------_.-----------a-
e i..W,
$CNSS897527.
i
'Attachm:nt If Page'l;
. RESPONSE TO POSITIONS OF NRC GENERIC LETTER 89 POSITION'l'- Full-Flow' Testing of Check Valves
'A check valve's full-stroke to the open position may' be. verified by passing the maximum: required accidentLcondition. flow through the valve.
"Any flowrate less.than this will be considered a partial-stroke exercise.
c.
A. valid full-stroke exercise by flow requires that the flow through the L,
. valve be ' known.. Knowledge of only the total flow through multiple l
parallel ' lines does not provide _ verification of flowrates through the l
individual. valves and is not a valid full-stroke exercise.
L
RESPONSE
For those. cases where the District is performing a full-stroke exercise of: check valves using system flow, the.flowrate through the subject valve p
-will be measured or derived by physical measurement with an acceptance criteria that is equivalent to the maximum required accident condition flow'through.the valve.
Where current procedures do not satisfy this l
requirement, appropriate revisions or.new procedures will.be initiated.
POSITION'lA - Alternative'to Full Flow Testing of Check Valves Where full flow testing of a check valve, as described above,'is impract-ical, it may be possible to qualify other techniques to confirm that a
. valve is exercised to the position required to perform its safety fune--
, tion. To substantiate tho acceptability of any alternative technique for meeting the Code requirements, licensees must, as a minimum, address and document the following in the IST Program:
1.
The impract.D:ality of performing a full flow test.
2.
A description of the alternate technique and a summary of the respective implementing procedures.
3.
A description of the method and results of the qualification program for the alternative technique, 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 baseline data has been generated when the valve is known to be in good working order.
6.
A description of the basis for the e.cceptance criteria for the alternative testing and a description of corrective actions to be taken when the acceptance criteria are not met.
CNSS897527 Attechm:nt I Page 2 c
. RESPONSE Where instances arise where full flow testing of check valves as described in Position 1 is not practical and valve disassembly and inspection (Position 2) may also be impractical, the District may inves-tigate alternate testing or inspection techniques that can effectively.
detect significant component degradation and provide the documentation and analysis of the position outlined above.
Such methods may include state-of-the-art electronic non-obtrusive sensors, radiography, or remote visual inspection.
The specific testing and inspection documentation will bn provided in the IST Program Plan.
POSITION 2 - Alternative to Full Flow Testing of Check Valves As an acceptable - alternate to full flow testing as described in Position 1, above, 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 exercise open or of' verifying closure capability, as permitted by IWV-3522.
If possible, parcial valve stroking quarterly or during cold shutdowns, or after re-assembly, must be performed.
RESPONSE
Where the District has determined that full flow testing of check valves as described in Position 1 is not practical, valve disassembly and inspection will be performed in lieu of flow testing along with partial valve stroking periodically and following re-assembly, when practical.
The specific testing and inspection plan will be provided in the pending revision to the IST Program Plan.
1%ere current procedures do not satisfy this requirement, appropriate revisions or new procedures will be 4
initieted.
I POSITION ?A - Inspection Procedure During valve testing by disassembly, the vr.lve internals should be i
visually inspected for worn or corroded parts, and the valve disk should
'j be nanually exercised.
RESPONSE
During valve testing by disassembly, valve internals will be inspected and exercised per the above guidelines. Appropriate acceptance criteria I
will be applied to assess valve operability.
1 1
POSITION 2B - Frequency of Disassembly Valve disassembly and inspection may 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.
I l
~
CNSSJ97527-
-Attachmeat 1 iPage 3 L
RESPONSE
1 Where specified'in'the reviewed IST. Program Plan, valve disassembly and
_ inspection will be performed during reactor refueling outages or other convenient' times _ based on the fuel cycle duration.
The revised Program
. Plan will include requests for relief whenever this option is_ utilized..
' POSITION 2C - Sampling Ins'pection Plans l
Where it is determined that_it is' burdensome to disassemble and inspect
. ll : applicable. valves each refueling outage, a sample disassembly and.
a g
inspection plan for groups of identical. valves in similar applications =
p may be employed. Guidelines for such plans are as follows:
The sample disassembly and inspection program groups similar valves and_ tests one. valve.in each group during each refueling outage.
Every valve in a group shall'be the same design (manufacturer, size, model, and materials of construction) and have the same orientation.
During valve-disassembly,. it must be verified that the valve is capable of full stroking by manually exercising and that the internals of the valve are structurally sound (no loose or corroded parts).
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 a 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.
Following this, the original sequence of inspection must be repeated unless extensfon of the insrection interval can be justified.
When disassembly / inspection data f or a valve group show a greater than 257 failure rate, a determination should be made as to whether the group size should be decreased or more valves from the group disassembled during each refueling outage.
Extension of the disassembly / inspection interval to ore valve every other interval, expansion of the group size above four valves, or other changes that would reduce the inspection interval for a ve.1ve to greater than six years should only be considered in cases of extreme hardship where the extension is supported by actual in-plant data from previous testing.
In order to support a frequency
(
extension to longer than six years, the following information should be developed:
a.
A documented report detailing the disassembly and inspection of each valve in the valve grouping, the conditien of each valve, and the valve's capability to be full-stroked.
_ y-R
CNSS897527
' Attachm::nt l' l
LPage 4
^
b..
A review of industry experience regarding the same type of valve used in similar service..
c.
A review of'the installation of each valve addressing the "EPPI F
' Applications. Guidelines for Check Valves. in Nuclear Power Plants" for problematic' locations.
RESPONSE' There.are.severa1Linstances where like valves in similar applications can be grouped'as described above.
If the District determines.that utiliza-tion of this. option is warranted, then the guidelines, set forth above -
will-be followed.
f, POSITION 3 - Backflow' Testing-of' Check Valves-Check valves that perform a safety function.in the closed position.to.
prevent reverse flow should be tested in a manner that proves that the
. disk travels to the' seat promptly on cessation or reversal of flow.
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 p; essure l-indication in the system, by leak testing, or by other positive means.
-RESPONSE-The revised.IST Program-Plan will identify all testing that.is required
- (open or closed) for each check valve in the Program.
The appropriate procedures for. backflow testing most of:the.chetk valves in the Program currently exist. For those cases where additional valves have been added to the program or where precedures are inadequate, procedures will be revised or developed to demonstrate that the valve is-properly performinF its safety' function'in the closed direction or that the valve is in the closed position.
- POSITION 4 - Pressure Isolation Valves (P1Vs)
All PIVs listed in the plant Technical Specifications should be listed in the IST Program as re,tegory A or A/C valves and the Technical Specifica-tion requirements referenced in the IST Program.
All Event V valves shall be individually leak rate tested and evaluated against the leakage limits specified in the Technical Specificat1ons.
RESPONSE
The Cooper. Nuclear. Station Technical Specifications do not list or designate any pressure isolation valver, thus this position does not apply.
_1_______________2_____
K:
~*
CNSS897527
'Attech nnt I n
.Page 5 POSITION 5 - Limiting Values of Full-Stroke Times for Power-Operated Valves The following guidelines are established regarding limiting values of full-stroke. time for power-operated valves:
-a.-
The limiting value of full-stroke time should be based on the valve reference or average stroke time when it is known to be in good condition and operating properly, b.
The limiting value should be a reasonable deviation from the reference stroke time based on valve size, valve type, and actuator
- type, c.
The allowable deviation in
.t ie time should not be so restrictive that it results in a valve beh declared inoperable due to reason-3 able stroke time variations.
d.
The allowable 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.
e.
In no cases shall the limiting value of full-stroke time exceed that required by Technical Specifications or Plant Safety Analysis.
RESPONSE
The District will review the acceptance criteria for the limiting values of full-stroke times for all power-operated valves in the Program that require stroke time measurements with regard to the guidelines presented above.
7.imiting values of full-stroke times and the implementing test procedures will be revised accordingly.
POSIfl0N 6 - Stroke Time Measurements for hapid-Acting Valves Power-operated valves with normal stroke times of two 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 tha licensee assigns a naxirem J tmiting value of full-stroke cime of two ccconds to these velves and, upon exceedir.g thir, limit, declares the valve inoperable and takes corrective actio7 in accordance with IWV-3417(b).
Since this is a deviation from Code require +
ments, it should be specifically documented in the IST Program.
RESPONSE
The District currently applies the requirements of IWV-3417(a) to all valve testing performed at Cooper Nuclear Station. However, in conjunc-tion with the review of all power-operated valve stroke times to be performed in response to Position 5, above, if the District should elect to identify some valves as " rapid-acting", the guidelines set forth above will be instituted.
l 1
1
E
~
CNSS897527 Attechmsnt 1
)
Page 6
)
POSITION 7 - Testing Individual Control Rod Scram Valves in Boiling Water Reactors (BWRs)-
Those ASME Code Class valves that must change position to provide the scram function should be included in the IST Program and tested in accordance with the requirements of Section XI.
These include.the scram discharge volume vent and drain valves, scram inlet and outlet valves,
~
scram discharge header check valves, charging water header check valves, and the cooling water header check valves.
Licensees should test these control rod drive system valves at the Code-specified frequency, if practical.
Scrsm Inlet and Outlet and Scram Discharge Header Check Valves If testing these valves could result in the rapid insertion of one or.
more control rods, the rod scram test frequency identified in the Technical Specifications may be used as the valve testing frequency.
Since this is a deviation from Code requirements, it should be specific-ally documented in the IST Program.
In lieu of measuring the stroke times of the scram inlet and outlet valves, verifying that the associated control rod meets the scram insertion time limits as defined in the Technical Specifications is an acceptable alternate method of detecting valve degradation.
If this method is used to verify operability of these valves, then it should be specifically documented in the IST Program.
Cooling Water He'ader Check Valves Demonstrating _the capability of normal control rod motion is an accept-able method of verifying the closure of these valves.
If this test method is used at the Code-required frequency, it should be clearly explained in the IST Program that this is the manner in which the Code exercising requirements are satisfied.
, Charging Water H6ader Chack Valves The CRD hydraulic control unit accumulator pressure decay test frequency as identified in the facility Technical Specifications raay be used as the charging water header check valve alternate test frequency, If this test is not nddressed in the Technical Specifications, the closure verifica-tion should be performed at least during each reactor refueling cutage.
Since this is a deviation from Code requirements, it should be specific-ally documented in the IST Program.
RESPONSE
The District complies with the testing requirements of this position except for the required documentation in the current version of the IST Program.
The revised IST Program Plan will include appropriate documen-tation.
,. ik
'"^
+5
CNSS897527
- Attachm:nt l'
- Page 7 POSITION 8 - Starting Point for Time' Period in TS ACTION Statements When test 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 Technical
~
Specification ACTION time clock must be started.
i RESPONSE-l l
The ' District' will establish appropriate administrative directives to comply with the position.
POSITION 9 - Pump Testing Using Minimum Flow Return Line With or Without Flow Measuring Devices In cases where flow can only be established through a non-instrumented minimum flow path during quarterly pump testing and a path exists at cold shutdowns or' refueling outages allowing test performance-under full or substantial flow conditions, the increased interval is acceptable provi-ded that. pump differential pressure, flowrate.. and bearing vibration measurements are'taken during this testing.
Ouring quarterly minimum.
flow testing, measurements of differential pressure and vibration must also be taken. Data from both of these testing methods should be evalua-l ted per the Code.
Since thiscis a deviation from Code requirements, it l
should be specifically documented in the IST Program.
l In cases where only the minimum flow return line is available for pump testing and no mechanism exists for testing at full or substantial flow where.flowrates can be measured, then flow instrumentation which meets i
the reqtrirements of IWP-4110 and 4120 must be installed in the mini-flow l
test circuit.
Licensees should ensure that if pumps are tested in a 1cw-flow condition, I
l the. flow is suffi;ient to prevent damage to the pump.
.j p
RESPONSE
I No minimum flowrate testing is performed rt Cooper Nuclear Station; thus 2
g this position is not applicable.
l-POSITION 10 - Containment I. sol.ation Velve Teuting i
All r.ontainment isclation valves (CIVs) included in the Appendix J j
Program should be included in the IST Program as Category A or A/C I
valves.
The licensee must comply with the Analysis of Leakage Rates and Correc-tive Action requirements of paragraphs IWV-3426 and 3427(a), however, the requirements of IWV-3427(b) need not be applied.
Since this is a devia-tion from Code requirements, it should be specifically documented in the IST Program.
l.
ly h *
,S ~
CNSS897527 Attachm:nt 1 Page 8-i
RESPONSE
All valves designated as containment isolation valves at Cooper Nuclear Station are included in the IST Program as Category A or A/C valves.
The District commplies with the requirements of IWV-3426 and 3427(a). An appropriate request for. relief from the requirements of IWV-3427(b) will be included in the revised IST Program Plan.
POSITION 11 - IST Program Scope Licensees should review their IST programs to ensure that the scope of the test program is adequate and accurately reflects the requirements of subsections IWP-1100 and IWV-1100.
RESPONSE
The District has conducted an extensive review of plant systems and the IST Program with respect to compliance with the requ1rements of IWP-1100 and IWV-1100.
As a result of this review and other aspects of this Generic Letter, the Program Plan is being revised to ensure that the scope is adequate and consistent with respect to the components subject to testing, and that the individual testing and the documentation requirements are properly addressed. Accordingly, procedure revisions or new procedures will be implemented in those cases where current test procedures will not adequately implement the revised Program.
- - _ _ _ - -