ML19330B577

Responds to IE Bulletin 80-14, Degradation of BWR Scram Discharge Vol Capability. One Occurrence Involving Scram Discharge Vol Level Switch W/Bent Float Stem Identified During 750418 Surveillance Testing

ML19330B577
Person / Time
Site:	Duane Arnold
Issue date:	07/22/1980
From:	Root L IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
IEB-80-14, LDR-80-203, NUDOCS 8008050058
Download: ML19330B577 (3)

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Iowa Electric Light and Pbwer Company July 22, 1980.

LDR-80-203 T

!.AARY D.wet ustsTA.NT ROO,atsicaNT NUCLEAa GLNEMitom Mr. James G. Keppler -

Office of Inspection and Enforcement U.S. Nuclear Regulatory Commission.

Region III 799 Roosevelt Road Glen Ellyn, Illinois 60137 Re: Duane Arnold Energy Center

Subject:

II Bulletin 80-14, Degradation of SWR Scram Discharge Volume Capability File: A-101a, NRC-2, Bulletin 90-14

Dear Mr. Keppler:

In response to your letter transmitting the subject bulletin concerning the scram discharge volume (SDV) level switch and drain valve failure events which could result in a degraded SDV capability due to undetected' water, we have completed the recem= ended licensee actions. The following discussion is provided to briefly describe the actions taken at DAEC to address these NRC IE Sulletin concerns.

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s SULLETIN ITEM 1. Plant maintenance records, Abnormal Occurrance (AC),

and Licensee Event Report (LER) . files were reviewed for instances of degradation of any SDV~1evel switch which was or may have been caused by a damaged or bent float assembly. One occurrance (AO Report 75-020) was identified during surveillance testing en April 18, 1975 which involved a SDV level switch with a bent float stem at DAEC. The cause of this occurrance was attributed to a manufacturing prchiam since a plastic foreign object was found in the

. switch reservoir. Subsequent surveillance testing revealed no further problems with the operability of this level switch. No other ficat stem problams have been identified with any of the DAEC SDV level switches.

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Mr'. James-G. - Koppler

'- Page 2 JJuly'22,-1980 BULLETIN ITEM!2.

Plant' records were-reviewed for instances of

. 1 degradation of SDV vent or drain valve opera-bility. No such problems were identified prior to:the recent DAECl reactor scram testing per-formed in accordance with IE Bulletin 80-17.

The recent scram testing revealed a problem with SDV drain' valve leakage which has been subsequently corrected.(Refer to LER 80-028 for detailed explanation).-

The SDV vent and drain valve closure times were-measured as part of the recently performed reactor scram tests. The average SDV vent valve' (CV-1859) closure time was 23.8 seconds and the average SDV drain valve (CV-1867) closure time was 21.4 seconds.

There are no DAEC Technical Specification or other requirements for, acceptable SDV vent and drain valve closure times.

3ULLETIN ITEM 3. DAEC has prepared a surveillance test procedure (SS-6, Scram Discharge Volume and Piping Water Test) which will verify by weekly testing that the SDV vent and drain valves are operable. These l valves are maintained in the ocen cosition as evi- ,

denced by valve position indication lights in the l control room and by verification by procedure (35-6) on a daily basis that these valves are open.

In order to comply with the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> prompt notifi-cation requirement, an OPERATING ORDER (42-94) has been issued requiring the Shift Supervising Engineer notify the NRC Operations Center in Bethesda, Md.

via the emergency notification system " red phone"'

if these valves are not operable or are closed for

. more than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in any 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period during opera-tion.

SULLETIN~ ITEM 4. No instances of water hammer or damage which may have been caused by water hammer in SCV related piping have been identified.by review of plant i records at DAEC.

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[ BULLETIN' ITEM;5. A review of the DAEC Technical Specification and I surveillance test : procedures (STP) was performed to' ensure that degradaticn of any SDV level switch 3

due to a' damaged float or other cause' would be detected by. periodic: testing.- The DAIC SDV level-switches are functionall, tested quarterly and l

!arel calibrated during each refueling outage (STP 41A006,'rischarge Volume High Water Level Instrument Functional: Test / Calibration).

Mr. James G. Kappler Page 3 July 22, 1980 BULLETIN ITEM 6. Following the recent scram testing and associated SUV outage work,- all of-the CAEC SDV level switches were functionally tested. This surveillance testing (STP 41A006) which verified the' satisfactory opera-tion of these swicches was completed on July 17,_1980.

If you have any questions or desire further information concerning this matter, please contact this office.

Very truly yours, q, b C7 Larry D. Rcot Assistant Vice President Nuclear Generation LDR/DWT/pl Docket No. 50-0331 Oc: U.S. Nuclear Regulatcry Cc= mission Office of Inspecticn and Inforcement Division of Reac:cr Operaticns Inspection Washington, D. C. 20555 U.S. Nuclear Re p lancry Ccemission c/o Document Mansgement 3 ranch Washington, D. C. 20555 D. Teoker D. Arnold L. Liu S. Tuthill K. Meyer D. Mineck D. Wilson J. Van Sickel NRC Ree4 dent Inspector-DAEC t

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Gentlemen: -

Enclosed is E Bulletin No. 80-14 which requires acnion by you wid regard j to your power reactor facilit7 with an operating license.

. . .... .a r- In order-to assist. d e 'dC in evaluating de value/L-cact of each bulletin on licensees, it would be helpful if 7ou would provide in estimate of de

. _C, , nanpower expended is ccaduct of the review and preparation of the report u.a: required. by de bulletin.. Please estimate separacaly the sanpcwer associ-7'A : aced. with corrective acti~ons necessary following identification of problems drough. the bulletin _ .

__ Should you have any questions. regsrfing this bul' ^ - the actions required by you, please: cont c _this office.

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UNITED STATES 8005050056 NUCLEAR REGULATORY COMMISSION OFFICE CF INSPECTICN AND ENFORCEMENT WASHINGTCN, D.C. 20555 June 12, 1920 IE Bulletin No. 80-14 OEGRADATICN OF EWR SCRAM OISCHARGE VOLUME CAFABILIT'f During cur review of BWR operating experience, two events have raised concarn on operations related to the centrol red drive systam scram discharge volume (50V).

Descriction of Circumstances:

At Hatch Unit 1, en June 13, 1979, wrile performing surveillance :: func-tionally tast SUV hign level switenes, two switches (C11-N015A, 3) were fcund to be inoperacle. Redundant swiccnes (C11-N013 C, 0) were cperacia. The reactor was in the refuel acce and these switches had been tcdified prior to this cccurrence. Inscection of -he incoeracie level switches revealed tna tne-ficat -red was-bent anc binding against the side of the fic'at cnamber en both switches. The licensee believes that the ficat reds were bent during or prior to initial installanicnuand that metal particles frca the acdifica:icn caused binding of the ficat: (LER 73-053) .

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Brunswick Uni:-l recertac= ca. : sicw closure of the EDV drain valve during a

- reactor scram en Oc:ccer 19, 1979 acparently. caused a watar hammer event wnicn

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damaged several pipe supports. on tne 50V drain line. Drain valve closure time was approximataly _five minutas due to a faulty solenoid controlling air supoly to the valve. The damaged pipe supports were repaired but repair parts for

. a the faulty soiencid were not available. To prevent possible damage from a -

scram, the unit started uc vith the 50V vent and drain valves closed except -

for periodic draining. During this acde of cperation the reactor scrammed frem-hign level.in the 50V, without prior actuation of either the high level alarm or rod bicck rwitch. Subsequent inscecticn revealed that the ficat ball on-thel red ble'ck switch was crushed and the ficat ball stam on the high level al_ ara ' switch was bent such that the switches would not operate. The water hammer ' event discussed above was the reportad cause of failure of these two

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switch assemolies. -(LER 79-74)

As a result of inese events and related anticipated transients without scram (ATWS) studies, concern arises that the 50V function may be degraded by the undetected presence of fluid in tne 50V. The second event is significant in that. it indicates the potential for a common cause failure (faulty solencid) to result in operation of the 50V in a manner wnica could defeat both the level switch function and the 50V draining function. The ATWS generic studies (NUREG 0460) have led the staff to prepose, accng other requirements, i=creve-ments in the 50V designs to reduce susceatibility to cc= mon cause failures.

By separate corresconcence, the staff will provide example Technical Specifica-tiens related to the action items discussed belcw.

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a. . = . .d.m June 12, 1980 Page 2 of 2 A. GE SWR's With an Oceratino License The following actions are to be taken by licensees of GE designed SWR facilities with an operating license:

1.' ~ Review plant records for instances of degridation of any SUV level switch which was or may have-been caused by a damaged or bent float assembly.

Identify the cause and corrective action for each instance.

2. Review plant records for instances of degradation of SDV vent and drain valve cperability. Provide the closure times required and typically cbserved for these valves and the basis for the recuired closing times.

Identify the cause and c:rrective action for each instance of degradation.

3. By procedures, require that the SDV vent and drain valves be normally

- operable, coen and periodically tastac. If these valves are not operable or are closed for more than 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> in any 21 hour2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> period during coeration, l the reasca shall be legged and the NRC no-ifiec wi-hin 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> (?romo.  !

Noti fication) .

A. Review instances in wnich watar hammer or damage which may have been caused by water hammer has occurred in 50V relatad piping. Icentify the cause and corrective-act. ion for eaca instance.

5. Review surveillanca= orccedures- to ensure nat degracation of any SUV level switch cue.t2 a=camagec ficat or c:her cause would be detected and that inoperacility from any cause would be reportac to the NRC.

5.. If no functional test or inscection which would detact degradation of

'each SDV level switch has been. performed during the past 3 months, make

.a previsions-to perform an inspection and functional test of all SUV level--

switch assemblies at the next:. reactor shutccwn of greatar than 18 hours2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br />

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S. Recortina Recuirements The action taken 'iI'~'e'sponse~

r to the items in Part A shall be c:=clated and a writtar .eport on the results submittad to the NRC within 45 days from the-date of this Bulletin.

This report shoulc be submitted to the Director of the aparecriata MRC Regional Office and a copy shculd be forsarded to the NRC Office of Inscection anc Enforcement, Division of Reactor Operations Inspection, Wasnington, D.C.

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Approved by GAO, ',130225 (R0072); clearance expires 7-31-30. Aporcval was given under a bl .nket clearance specifically for identified generic preolems.  ;

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IE Bulletin No. 80-14 Enclosure June 12, 1980 RECENTLY ISSUED IE SULLETINS Bulletin Subject Data Issued ' Issued To No.

80-13 Cracking In Core Spray 5/12/80 All BWR's with an Spargers OL 80-12 Decay- Heat Removal System 5/9/80 Each PWR with an OL Operacility 80-11 Masonry Wall Design 5/8/80 All pcwer reactor facilities with an OL, excepc Trojan '

a 80-10 Contamination of 5/5/50 All pcwer react:r Nonradicactive Systam and facilities witn an Resulting Potantial for OL or CP Unmonitored, Unc:ntrolled Release to Environment 80-09 Hycramotor-Actatar 4/17/80 All pcwer react:r Defici enc.i as_

operating facili-ies and holders of ccwer reac ce construc-icn permit.s 80-08 . Examination..of Centainment 4/7/80 All pcwer reactors with

~; . . _ . . Liner-Peitetration Welds a CP and/or OL no latar

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.than April 7, 1980

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80-07' BWR Jet Pu:dii Assemoly 4/4/80 All GE-SkR-3 and

?M- Failure . .

.- EWR-4 facilities with I

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.:.> :- e 80-06: Engineered Safety feature 3/12/80 All cower reactor

?!r (ESP) Reset C:ntrols facilities with an OL

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80-05? Vacuum Condition Resulting 3/10/80 All PWR power reactor f .In Damage Io Chemical Volume facilities holding Centrol System (CVC5) Holdup OLs and to those with Tanks a CP 79-018' Environmental qualification 2/29/80 All acwer reactor of Class IE Equipment facilities witn an OL 80-04 Analysis of a PWR Main 2/8/80 All PWR reactor facilitie Steam Line Break With holding OLs and to those Continued Feedwater nearing licensing Addition . . ,

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