ML20029B133

LER 91-004-00:on 910125,control Room Radiation Monitor Alarm/Trip Setpoint Greater than Normal.Caused by Personnel Error.Operations Manager Will Counsel Shift Supervisors & Night Order Will Be posted.W/910227 Ltr

ML20029B133
Person / Time
Site:	Arkansas Nuclear
Issue date:	02/27/1991
From:	Ashley G, James Fisicaro ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
2CAN029114, LER-91-004, NUDOCS 9103050474
Download: ML20029B133 (4)

Text

I l

5"i = ** "' "a a i" = -

~

n- Entern"T U n .

Operations >

4

_ m ._

February 27, 1991 2CAN029114 U. S. Nuclear Regulatory Commission Document Control Desk Hall Station PI-137 WashJngton, D. C. 20555

SUBJECT:

Arkansas Nuclear One - Unit 2 Docket No. 50-368 Licenso No. NPF-6 Licensee Event Report 50-368/91-004-00 Gentlemen:

In accordance with 10CFR50.73(a)(2)(1)(B), attached is the subject report concerning a failure to maintain the control room ventilation system radiation monitor alarm / trip sotpoint value within Technical Specifications dun to a personnel nrror.

Very truly yours, ,

w .h

'ames J. 'inicaro Hanager, Licensing JJF/GRA/mmg Attachment cc: Regional Aditinistrator Region IV U. S. Nuclear Reguletory Commission 611 Ryan Plsza Prive, Suite 1000 Arlington, TX~ 16011 INPO Reccrds Cente.

t Suite 1500 1100 Circlo, 75 Parkwny Atlanta, GA 30339-3034 4

a' 9103050474 910227 I i

PDR ADOCK 05000368 >

l

$ PDR

!w .;.?

NRC Foro 366- U.S. Necimr Regilaton Cognissich

. (6-89) Apprtwi Olli No. 3150-0104 Expires: 4/30/92 LICENSEE EVENT REPORT (L E RJ FACILITY NVE (1) Attansas Nucimr Oe, Unit %o  ;

IE E ET NLiiWR (2) l PKE (3)

M5_[ddd_3L6[ 81l0F{d3 TITLE (4) Failure To Maintain Gmttul Ratxn Ymtilatim Systm Rallatim tinitor Alann/ Trip Setpoint Value Within Tec!nical SgcifIcaticas 11m To Purncavel Errur EVENT IM1E (5) IFR 4tiBIR (6) RElu{r IWIE (7) G1EIEACILITIES IMUMD (8)

S(gamtlal Revisim tkuth Ay_ Year Yer Ntsnint Ntaler Mmth Diy_ Ymr Facility Niunns Ibcket NtunLor(sL ANr)-1 0 5 0 0 0 3 1 J

_0.[1_. 2[5 _9, _lL9] 1 --

0j 014 n 010 Ol_2_2L7 9{l 0 5 0 0 0 Of1RATIhD 1111S IEITI IS SUltiIT1H) PLRSUAYr 3D 11E ElI7]Ilan% OF 10 GR 9:

ITIE (9) 1 (Cmch me or mgra.RLihe folltWhE) (11) .

fWER _ 20.402(b) _j20.405(c) _ 50.73(a)(2)(iv) _ 73.71(b)  !

IEVEL _

_ 20.405(a)(1)(1) _ 50.36(c)(1) 50.73(a)(2)(v) _ 73.71(c) 1 10)_ 0 [8{8 _ 20.405(a)(1)(ii) ._, 50.36(c)(2) _ 50.73(a)(2)(v11) _ Other (S F cify in

_ 20.405(a)(1)(111) .1 30.73(a)(2)(1) _ 50.73(a)(2)(viii)(A) Alstract lelow artl 4

. 20.405(a)(1)(iv) _ 50.73(a)(2)(ii) _ 50.73(a)(2)(viii)(II) in Text, NRC Fonn 20.40S(a)_(1)(v) 50.73(al(21(iii) 50.Ma)12)(x) 366A)

LUAMI GNTNIT RR 1111S IER (12)

Nam ._Jehitmq1 tier _ _.

Area Giann A. Ashley, Nuclear Safety att! Licmsing Specialist Otxic Sjg19[6[@;$}QQ0 QNIDE QW, LINE ITE FNU Q1111MNT FAIIIMUTRRIIED_IN_1UIS RIERrJ13)

Reportable Reportable Cause Systm Ocument tkinufacturer to NPR[E faunt SXHim_CGUImk Kmiufacturer _lo NIME I I I I I I l I I I I I I I

._l .I I I IIL SUP11RE'T RElmr EX1H711D (14) l__ _I I l_ l .L_i_

IXIHIIID lirth Ihy_1mr_

_. SUltilSSKN l l Yes (If yesucrnplete Expectn! Sulmissim lhte) [Xl No _ ._ IW1E (15) _ l l l 4 AIEIRNIT (Limit to 1400 spaces, i.e. , apptuximately fif tem singlo-apace tyr writtm linm) (16)

On January 28 1991 it was discovered that the Unit 2 control room radiation monitor had an alarm / trip setpoint greater than two times background and the control room emergency ventilation system had not boon placed in the recirculation modo as required by Technical Specifications. On January 25, 1991 the average background was determiend to be 83 counts por minuto (CPM) and the alarm / trip setpoint at that time was set to 200 CPH. A job request was initiated to have the setpoint adjusted.

It was not recmized until January 28, 1991 that Technical Specification 3.3.3.1 required the setpi. int be adjusted within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. The control room ventilation system was placed an the recirculation mode, and subsequently, the setpoint was adjusted to 150 CPM. The event had no adverse impact on control room habitability; the capability of thi monitor to perform its intended function was meintained. The root cause of this event was personnel error. The Operations Manager has issued a night order to remind operations personnel of the requirements of Technical Specification 3.3.3.1, and this event will be discussed during the training cycle following the 2R8 refueling outage.

l l

U. S. Nm1mr Engulatory umit.alen NRC rota WA

• Atynwn! OtB No. 3150-0104 (6f)'

hydtm: 4/'K1/92 L10?N2; IMNi L13tRf (117) lin GhTINUATi(N

'It03*f NMR (2) 14fflEl@ PN3; (3)

TN:Ihrr[Ein (1) Sapotial Revinim

\

Attansas Nuclear Oe, linit 'tw Y& nmixL._ _ .nmLct .

O 51AloigL6La .913_

l o L914 -

ALo_ol2ksM3 11XT tif noro s;nco is intuimi, tne ntiltkunt NT

• WA n) (17)

A. Plant Status At the time of discovery of this event, Arkansan Nuclo ; One, Unit Two (ANO-2) was operating in Hodo 1 (Power Operatioti) at apptoximately 48 porcerit of rated thermal tiower. Roactor Coolant System (RCS) temperature was approximately 576 degrees Fahrenheit and kCS pressure was about 2250 pain.

B. INent Description On January 28, 1991 it was discovered that the Unit 2 control room ventilation nyatom radiation monitor (2RITS+8750-1) had an nintm/ trip sotpoint greater than two times background and the control room emergency ventilation system (Yl] had not been placed in the recirculation modo of operation as required by Technical Spetification 3.3.3.1.

On January 25, 1991 during the midnight shift, the average Lackground count rate for the control room radiation monitor (2RITS-8750-1) was calculated using data from the Process Hnnitor Lon. The averag'.i of the three readings f rom the previous day wcs determined to be 83 counts por minute (CPM). The alaim/ trip notpoint at that time was set to 200 CPH. The Process Monitor Log speciflod that. the sotpoint be adjusted if the _notpoint was greator than two timon the average reading. Therefore, operations personnel initiated a job requsst to have the setpoint adjunted. It was not recognized that Technical Specification 3.9.3.1 required the notpoint be, adjusted withi. 4 hourn or the associated monitor be declared inoperable. If the radiation monitor in declarod inoperable, initiation and maintenanco of the control room emergency ventilation system in the recirculation modo of operation must be accomplished within one hour.

At npproximately 0755 on January 28, 1991 operations personnel reviewing the Procons Monitor hogn realized that the requirements of Technical Specification 3.3.3.1 had not boon satisflod. At that timo the radiation monitor was declared inoperable and the ventilation aprom was placed in the recirculation modo. Tho

. radiation monitor clarm/t rip sotpoint was adjusted to 150 CPM and at 1700 on January 28, 1991 the Technical Specification action ntatement was cleared.

C. Root Cause The root cause of this event was personnel error. The Process Monitor Log that was used to record the radiation monitor readings and to calculate the average 1 background reading referenced Technical Specification 3.3.3.1 and required the operatius personnel to have the setpoint adjusted if the existing notpoint was greater tnan two times the average background reading. The Waste Control Operator (non licensed operator) completing the log and the Shift Supervisora reviewing the log did not refer to Technical Specification 3.3.3.1 to datormino the required actions and did not recognize that the action required by the Procons Monitor hog had timo limits specified in the Technical Spotifications.

NHC fore 366A lt. 8. Noclent Regulatory Canninnim (t @)*

- Amtom! OtB !b. 3150-010

. . Expirent 4/30/9;'

LIGNE ININT WIRiff (!JR) 11XT owr 1RIAT104 TACIL11Y KE (1) 11n1.7 RMin (2) 1 4 N M ER (O I#E (3)

Saputtial Revisim Arkatsas !bclevtr am, thit Two in _ _Jknter junts.

Oliololol/JJLL911 0lAl4 -

010 al*El9h 11XT (If more since is rnlutral. tse attiticani NiC Fotw MA 6) (17)

D. Correctivo Actions The Operations Manager will counsol the Shift Supervisors involved J.n this event regarding the need to thoroughly investigato Technical Specification reinted conditions by March 15, 1991.

The Operations Manager has issund a night order to remind operations personnel of tht requirements of Technical Specification 3.3.3.1.

The Operations Manager will discuss this event with all operating crews during the roqualification training cycle following the upcoming 2R8 refueling outage.

The discussion will emphasize that Technical Specification requirements must be properly identified and compliance muut be ensured for sections of the operations logs that reference the Technical Specifications.

F. Safety Significance With the alarm / trip setpoint romaining at 200 CpH, the control room ventilation system radiation monitor was still capable of performing its intended function to autcmatically initiate isolation of thn cont rol room f rom elevated airborne radioactivity to maintain control room habitability. Since the menitor background varies such that a setpoint greater than 200 CPM is not unusual, the-monitor would continue to alarm /antuate on airo rne radiation levoln significantly below occupational exposure limits. Therefore, leaving the setpoint at a value greater than t w times background for a time period granter than allowed by Technical Specifications has no actual safety significance.

.F. Basis For Reportability This event is reportable under the provisions of 10CFR50.73(a)(2)(1)(li), as operation prohibited by Technical Specifications. Specification 3.3.3.1 requires that the control room ventilation system endiation moniter be operable with the monitor sotpoint at loss than or equal to two times background. With the setpoint exceeding the specified value, four hours are allowed to adjurit the setpoint to within the limits. Otherwise, within one hour the control room escrgency ventilation system must be placed in the recirculation modo of operation. As a result of this event, the monitor was operated with the setpoint above the required limit. beyond the allowable four hours and without placing the control room emergency ventilation oystem in the recirculation mode.

G. Additional Information Thoro have been no 'other similar events caused by personnel error reported at Arkansan Nuclear One.

Energy industry Identification System (Ells) codes are identiflod in the text as U*X ) .

___ __