NG-93-0222, Resubmits Relief Request VR-004 & Modifies VR-003 & VR-005 Re Inservice Testing
| ML20128E758 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 01/29/1993 |
| From: | Franz J IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT |
| To: | Murley T Office of Nuclear Reactor Regulation |
| References | |
| NG-93-0222, NG-93-222, NUDOCS 9302110060 | |
| Download: ML20128E758 (8) | |
Text
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I lowa Electric Light and Power Company JOHN F. I'RANZ, JR.
vitt paruorwr, mutan g
NG-93-0222 Dr. Thomas E Murley, Director Office of'Noclear Reactor Regulation U. S. Nuclear. Regulatory Commission Attn:
Document Control Desk Mail Station P1-137 Washington, DC 20555
Subject:
Duane Arnold Energy Center Docket No 50-331' Op. License No: DPR-49 DAEC IST Relief Requests VR-003,.VR-004, VR-005
Reference:
Letter from D. Mineck :(Iowa Electric) to-Dr. T. Murley (NRC) dated October 15, 1990 (NG-90-2454)
File:
A-10lb, A-286e-
Dear Dr,
Murley:
Iowa Electric Light and Power Company previously submitted revisions to Duane Arnold Energy Center (DAEC) Inservice Testing-(IST) Relief Requests VR-003 and VR-005.(Reference).
That
-submittal also withdrew Relief-Request'VR-004.
-We have'since identified the need to resubmit request-VR-004 and to modify-requests VR-003 and VR-005. -These-changes are-discussed-in Attachment.l.
.The relief requests are-Lcontained-in Attachment 2.
We. request approval of these. requests prior to the next refuel' s
outage currently scheduled to begin July 29,11993.-
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Should you;have any questions regarding.this matter,.please.
contact =this office.
-Very-truly yours, 050053 I
ohn F.
Franz ice-President, Nuclear
_lJFF/CJR/pjv' 9302110060:930129-
- PPDR 'ADOCK 05000331 1
pop General office
- P.o. Box 351
- Cedar Rapids, Iowa 52406
- 319!398-4411 l-y; s
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.j Dr.-l Thomas ~E.
Murley4
- January;29', 1993 NG-93-0222
-Page 2
-Attachments:-
11)
' Description of-Changes 2)
Relief Requests VR-003,:VR-004 and:-VR-005 cc:
C. Rushworth' t
L.- Liu L.
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R. Pulsifer-(NRC-NRR)
A.
Bert Davis-(Region III)
NRC Resident Office i;(
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AttachmentJ1 to_-
.NG-93-0222:
- Page-1)of 1:
-Description of Changes
-Relief Request =VR-003 Relief Request VR-003 has been revised.to implement 1 flow testingL on a refueling outage basis rather thanEexercising with a.
mechanical exerciser.
This change will provide a more reliable assurance of check valve. operability since actual system flow is used to exercise the valve disk.
Relief Request VR-004
. 1 Relief Request VR-004 ic being resubmitted due to modifications-made to feedwater-check valves V-14-0001 and-V-14-0003. 'The:
actuating mechanisms and position indication lights were removed, from these valves during-the last refueling outage ~1nLorder to-improve the valves' ating capability, and-therefore, leak-tightness.
Because ae position indication lights have?been-removed,-it is no longer possible to perform the "exerciseLclose test" during Cold Shutdown.
Relief Request VR-005-Relief Request VR-005 has been revised to include the Main Steam Safety Valves PSV-4400 through PSV-4407.
Additionally, a statement has been added to the description of alternate : testing._
to state' Iowa Electric's position on_setpoint restoration during_
testing.
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-Attachment 2 to
.NG-93-0222 Page 1 of 5 9
RELIEF REQUEST NO. VR-003 SYSTEM:
Residual Heat Removal COMPONENTS:
V-19-0149 V-20-0082 CATEGORY:
A/C FUNCTION:
These valves open to provide a~ pathway for LPCI flow into the' recirculation system and close to isolate the RHR system _from the high pressure of'the recirculation system.
TEST REOUIREMENT:
Check valves shall be exercised at least every 3 months. (IWV-3521)
BASIS FOR' RELIEF:
These valves-cannot be stroked during power. operation.because-the RHR pumps cannot develop sufficient head. to overcome recirculation system pressure. These-valves-cannot be manually stroked during operation because they. are located in the drywell and are inaccessible.-
In-situ testing has ' determined that.these check valves fully c.
open at approximately 4000 gpm. To ensure compliance with.IWV-3522, positive verification ~of-valve operation is1 required. To l
achieve this verification, a mechanical. indicator is. attached to L
the rotating shaf t.
This testing.cannot be ' condu'cted ~ at Cold l
Shutdown because the containment is inerted with nitrogen. In-order to gain personnel access to the drywell, the nitrogen must' be ~ vented (normally. a 16 - 24_' ht,ur-operation). The containment must be re-inerted before the plant is restarted (another 16 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> operation). Inerting and de-inerting the drywell solely for the. purpose of valve testing is excessively burdensome.
Additionally, a full stroke ' test of these' valves cannot be l~
performed swith flow at Cold shutdown because it would be necessary to test'two channels / loops of a safety system at~the same-time. Current' guidance only. allows the-operation of one train.of a safety-system for_ surveillance ~ purposes.
... -. ~. ~ -. -.
'n 9
-Attachment-2 to NG-93-0222 Page 2 of 5 RELIEF REQUEST-NO. VR-003 (Continued)
One of these valves is partially stroked during Cold Shutdown-for the operation of the shutdown cooling mode of RHR. This'is only a partial stroke test hs the normal flow rate in this mode is only 4000 gpm versus a maximum required accident flow rate of 14,400 gpm and no positive verification of-valve position - is made. While shif ting' system operation to the idle loop -is-possible, it is a time consuming operation. In order to. change.
loops and inject cooling flow through thd other loop, more than 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> of preparation and lineup work would be required of the-control room personnel, assuming no other testing / duties ongoing at the time.
ALTERNATE TESTING:
One of these valves will be partially stroked to' the open position each cold shutdown.
V-19-0149 and V-20-0082 will be. stroked. to the full open position during each refueling outage, utilizing a mechanical position indicator to prove positive valve operation.
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' Attachment 2 to-NG-93-0222
. Page 3,of.5 -
RELIEF REQUEST NO. VR-004 SYSTEM:
Nuclear Boiler-C_OMPONENTS:
V-14-0001 and V-14-0003 CATEGORY:
A/C FUNCTION:
These valves are the reactor feedwater supply inboard isolation valves.
They open for feedwater flow, RCIC and HPCI injection into the vessel and act as containment isolation valves.
TEST REQUIREMENT:
Check valves shall be exercised at least every 3 months.
(IWV-3521)
BASIS FOR RELIEF:
The valves cannot be exercised during power operation. During plant operation at power, reactor feedwater is supplied-through both. valves to maintain reactor coolant inventory in the reactor vessel and maintain reactor vessel water level.
Closing either of.these valves will isolate two of the'four supplies of feedwater into-the' reactor vessel.
This action-could result in thermal shock to the reactor vessel feedwater nozzles and spargers upon resumption of flow and a plant trip due to the potential severe reactor vessel. water level transients.
These valves cannot normally be tested-during Cold Shutdown because the containment is inerted with' nitrogen. Personnel would be required to access the drywell to Lperform
_a mechanical exercise t.,4 these valves. The - nitrogen _ must.be-vented (normally a 16-24 hour - operation).
The-containment must be re-inerted before the plant is restarted (another 16-24 hour operation).
Inerting and de-inerting the dryuell solely for the purpose of testing is excessively burdensome.
In addition, the LLRT is done with' air, therefore, the line-between the check valves and upstream isolation valve must be:
drained.
This is a time-consuming process resulting in lengthened shutdown times and unnecessary hours of exposure.
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_ ___ -. to NG-93 0222
'Pago 4 of 5 I
RELIEP REQUEST NO. VR-004 (CONTINUED)
ALTERNATE TESTINGt t
The valvos will be assumed to be in-the open position if the foodwater system operates properly during normal-plant operation.
The valves will be exercised to the fully closed l
position each refueling outago and verified by local leak rato l
testing. In addition, during each refueling outago, one of-these valves will be disassembled and inspected for full stroke operability in accordanco with requirements of USNRC Generic Lotter 89-04. Thus, both valvon will be disassembled and inspected once every two refueling outages. The normal operation of'the foodwater system and plant will fulfill the partial flow test of these valves.
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4 Attaclunent 2 to NC-93-0222 Bige 5 of 5 RELIEF REQUEST NO. VR-005 l
SYSTEH1 Various COMPONENTSt PSV-1911 PSV-2122 PSV-2609 PSV-4439B PSV-4403
-i PSV-1952 PSV-2129 PSV-3221A PSV-4439C PSV-4404 PSV-1975 PSV-2223 PSV-3221D PSV-4439D PSV-4405 PSV-1988 PSV-1228 PSV-3222A PSV-4439E PSV-4406 PSV-2043 PSV-2301
_PSV-3222B PSV-4439F PSV-4407 PSV-2057 PSV-2430 PSV-3223A
-PSV-4842 i
PSV-2068 PSV-2474 PSV-3223B PSV-4400 PSV-2102 PSV-2501 PSV-4336.
PSV-4401 PSV-2109 PSV-2607 PSV-4439A POV-4402 CATEGORY:
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EURCTIQlli These valves provido overpressure protection to.the associated system components.
TEST REOUIREMENT!
Safety and rollef valves shall be tested in accordance with Subsection IWV-3510.
BASIS FOR-RELIEEL ANSI /ASME OM-1-1981, " Requirements for Inaervice Porformance Testing of Nuclear Power Plant Pressure Relief Devicos",- was developed to supersede the requirements of Subsection IWV-3510.
This standard is - more definitive and better uulted; to operational testing than is. ASME/PTC 25.3-1976 which 'is referenced'in IWV-3512.
ALTERNATE TESTINQi
. Safety and reliof valveo-will be tested in accordance with the
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requirements of-ANSI /ASME OM-1-1981..During. testing,.
tho-setpoint will.be restored to within the specified tolerance lof thol original Installation / Construction /Flanufacture Code before the safety / relief valve-is reinstalled.
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