ML20043C728

LER 90-008-00:on 900505,determined That Reactor Vessel Head Vent Valves 1B21-F004 & 1B21-F005 Closed Contrary to Tech Spec 3.7.C.2.a(2) Requirements.Caused by Cognitive Personnel Error.Reactor Vessel Head Vent Valves reopened.W/900531 Ltr

ML20043C728
Person / Time
Site:	Hatch
Issue date:	05/31/1990
From:	Hairston W, Tipps S GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
HL-1124, LER-90-008-01, LER-90-8-1, NUDOCS 9006060110
Download: ML20043C728 (7)

Text

, - - - .. - -

t Oeyga Power Comtmy  !

333 Piedmont Amnue ,

, Manla Geo<g a 33308

• . lTeiophone 404 526 3195 Mvhng Andress ,

40 Ir erneu, Cen'er Pa4 way 1 Pos! Ofice Don 1?95 ,

Birmn;Piam A:atema 3E201  :

Telephow 205 868 558t  ;

t*n: vnt'am mvim w.ttm '

W. G. Hairston,111 son.or vec Presiden:

Nuttear Operations HL-ll24 000621 May 31, 1990 .i U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 PLANT HATCH - UNIT 1 NRC DOCKETS 50-321 OPERATING LICENSE DPR-57 LICENSEE EVENT REPORT PERSONNEL ERROR RESULTS IN A CONDITION PR0HIBITED BY TECHNICAL SPECIFICATIONS Gentlemen:

In accordance with the requirements of 10CFR50;73(a)(2)(i), Georgia Power Company is submitting the enclosed Licensee Event _ Report (LER) concerning an event wherein a personnel error resulted in a condition prohibited by the Technical Specifications. This event occurred at Plant Hatch - Unit 1.

Sincerely, ud.k. l W. G. Hairston,-III SDR/SJB/eb

Enclosure:

LER 50-321/1990-008 c: (See next page.)

9006060110 900531 PDR ADOCK 05000321 s PDC

, _ $b h 4

, ///

U.S. Nuclear Regulatory Commission May 31, 1990 ,

Page Two c: Georaia Power Comoany Mr. H. C. Nix, General Manager - Nuclear Plant Mr. J. D. Heidt, Manager Engineering and Licensing - Hatch r GO-NORMS U.S. Nuclear Reaulatory Commission. Washinaton. D.C.

Mr. L. P. Crocker, Licensing Project Manager - Hatch U.S. Nuclear Reaulatory Commission. Reaion 11 Mr. S. D. Ebneter, Regional Administrator Senior Resident inspector - Hatch

+

e b

l i

l l

l l '

l 000621

R perm ans U S Nuctta.w EsiUL110RY COMMessioN MPROVID OMS NO 31eD010s

, LICENSEE EVENT REPORT (LER) ***'a'*"'" l 1

flC6LitY NAMS fil DOChil NOMSIR (2) I AOI 63' I PLANT HATCH, UNIT 1 o l5 I o Io I o 131211 1 loFl 015 fitLt top PERSONNEL ERROR RESULTS IN CONDITION PR0HIBITED BY TECHNICAL SPECIFICATIONS EVINf DAf t (Si Le n NUMalR ISI R4 PORT DAff th OTHIR f ACILITill INVOLVED ISI MONTH DAY YiAR VI A81 "[j *"b

, ((M MONTH DAY vt Api 8ACit,t. NAwlt DOCA L T NUM9t84t$1 0 16101010 f I I 0l5 0l 5 9 0 9l0 0 l 0l8 0j0 0l 5 3l1 9 l0 oistoioici l i opt R atlNO THit ALPORT 18 $USMittID PURSUANT TO THE RtQUIREMENT$ OF 10 C8R $ ICheca o e se msg of rae fo9ee nsi nli Met ai 5 a m., n .0. .i .0 n .u,n.,, n n.,

g 0 i 0, 0 n 40.i.inibi .0 mi.ini .0. ni. Ha n.> n n .i n0, n .0 4.,n n., 0 =i.n,i

.0 n.n,H..,

_ ggsg g 20 40GlaH1thail 60.?Jtell2nti 60.73 ett2HveiaHAl .pM1 20 406teH1He.) 60 73(alt 2Hal 60 73iaH2itvikHB; 30 406tetiill.) 60 73(aH3H6hl 60 niet(2Hel LICENtit CONT ACT 80m THIS Lt R n21 Navl TELEPHONE NUMetR nmt A COD 4 Steven B. Tipps, Hanager Nuclear Safety and Compliance. Hatch 911 12 316 17 1-17 1 81511 COMPL t f t ONE LINE f OR S ACH COMPONINT f AltuRt DISCRigf D IN THIS REPORT 118)

C Aunt sysitu COMPONIN/ M' "I' '

• Ma" " " 8L tO NPRDs Caunt avsTtw 00VPONtNT y tO NPR 5 I I I I I I l l i i i I .t i l l I I I I I I I I I I I I SUPPLEMINT AL REPORT E RPICit0 (14) MON 1H DAY vlAR q vts <<< >.. - . rorcrev svovissioN oor, *nn"T T] No _ l l l A.,1RAcr,t..,M,w,,,,,,...,,.~,,,,....y..,.<,,,,,,..,.....n.,

l On 5/5/90, at approximately 0500 CDT, Unit 1 was in the Refuel mode with reactor coolant temperature at approximately ll2'F and reactor coolant pressure atmospheric.

At that time, with modified secondary containment established. licensed plant operations personnel discovered that the Unit 1 reactor vessel head vent valves, 1821-F004 and 1B21-F005 (Ells Code VTV), were closed. This condition was contrary to the requirements of Unit 1 Technical Specification section 3.7 C.2.a(2) which states that the reactor coolant system (RCS) must remain vented whenever modified secondary

- containment is established. Investigation showed the head vent valves had failed closed when air to the drywell was isolated under an equipment clearance on 5/4/90.

Secondary containment for the operating unit, Unit 2, was unaffected by this condition.

The root cause of this event was cognitive personnel error. The licensed Shift Supervisor who authorized the clearance did not realize the reactor head vent valves were required to remain open to maintain Technical Specification compliance.

Further, the requirement to maintain a vent path and the method used-to meet that requirement were not covered by procedure.

! Immediate corrective actions included removing the clearance and reopening the l

reactor vessel head vent valves. Corrective actions to prevent recurrence include counseling the responsible Shift Supervisor and examining methods of reliably venting the reactor coolant system while in modified secondary containment and including the method (s) and the requirement to maintain a vent path in procedures.

l ""c( " "'

.l

o, nace .Sua v2 wuCL :a asutuoav comuimio=

LICENSEE EVENT REPORT (LER) TEXT C!NTINUATION uenonoousno mo-oio4

. EXPIRES 4t31/88 F ACILITV suAML tip Docetti seUMDia (3l gga muusta(68 P&O8 (31 nA= " % ;'.", W:u:

0 ls lo lo lo l3 l 211 910 010 0l2 oF

( PLANT HATCH. UNIT 1 f tXT t#more apsee 4 soowsost use caprenst AWC Form .,BSA W I1M Ol0l8 -

0 15 l PLANT AND SYSTD1 IDENTIFICATION l General Electric Boiling Water Reactor Energy Industry Identification-System codes are identified in the text as (EIIS Code XX).

SUMMARY

OF EVENT On 5/5/90, at approximately 0500 CDT. Unit 1 was in the Refuel mode with reactor coolant temperature at approximately 112'F and re6ctor coolant pressure atmospheric. At that time, with modified secondary containment established, licensed plant operations personnel discovered that the Unit 1 reactor vessel head vent valves,1821-F004'and 1821-F005 (EIIS Code VTV), were closed. This condition was contrary to the requirements of Unit 1 Technical Specifications section 3.7.C.2.a(2) which states that the reactor coolant system (RCS) must remain vented i whenever modified secondary containment is established. Investigation showed the  ;

head vent valves had failed closed when air to the drywell was isolated under an i equipment clearance on 5/4/90. Secondary containment for the operating unit, Unit 2, was unaffected by this condition. J The root cause of this event was cognitive personnel error. The licensed Shift Supervisor who authorized the clearance did not realize the reactor head vent valves (

were required to remain open to maintain Technical Specification compliance.

Further, the requirement to maintain a vent path and the method used to meet that requirement were not covered by procedure.

Immediate corrective actions included removing the clearance and reopening the ,

i reactor vessel head vent valves. Corrective actions to prevent recurrence include counseling the responsible Shift Supervisor and examining methods of reliably -

venting the reactor coolant system while in modified secondary containment and including the method (s) and the requirement to maintain a vent path in procedures.

On 5/21/90, at 0135 CDT, in accordance with the outage work plan, normal- secondary containment was established for Unit 1, thus eliminating the requirement to vent the RCS.

DESCRIPTION OF E.V_E..N_T.

On 4/23/90, equipment clearance 1-90-1111 was drafted to support outage work. The clearance included steps for isolating instrument air in the drywell. At the time the clearance was drafted, the reactor vessel was disassembled with the vessel: head removed. In this condition the reactor coolant system is continuously vented. .On 4/26/90, prior to actually performing the clearance, the reactor vessel head was reinstalled with the head vent valves open. These valves were required to remain open in order to provide a vent path for the reactor coolant system and thus -

preclude reactor vessel pressurization while secondary containment for Unit 1 Reactor Building was not being maintained (modified secondary containment in effect).

BGC90 M besA *V 3* G'O' I M

• W * * '

• Tr43)

, -e

NRCFeem 3e6A U.S NUCLE A) LETULATORY COntMARSION

' * *  ; LICENSEE EVENT REPORT (LER) TEXT C3NTINUATION Amoveo ous wo. ai:wo.

. IxPant S. D'3)'80

,,EILIT Y h&Mt Hi DOLK E T NVtADE R til ggR NUMSER ISI PA06 t3l vlam at e AL N

{a p PLANT HATCH, UNIT 1 rnxtw m <ecom,anavon o [s lo jo j o l3 l 2l1 9l0 _

0l0l8 _

0l0 0l3 or 0 l5 On 5/3/90, at approximately 2225 COT, clearance 1-90-1111 was authorized by a licensed Shift Supervisor. This authorization allows performance of the equipment clearance, including closing and tagging specified valves. In authorizing this clearance the  ;

Shif t Supervisor was aware that the reactor head vent valves would close as a result. '

He did not realize that closing these valves would violate a Technical Specifications req'. i remen t. Specifically, he did not realize that these valves were being solely relied upon to vent the RCS as required by section 3.7.C.2.a(2). No procedure required that these vent valves remain open. The clearance was implemented on 5/4/90.

The fact that the valves had closed was not immediately apparent to control room operators. Valve position is not annunciated but is provided by position lights  ;

located on one of the control room equipment panels.

l On 5/5/90, at approximately 0500 CDT, a licensed control room operator noticed that the vent valves were closed, and reported this fact to the licensed Shift Supervisor. It was recognized that the vent valves were required to be open in order to satisfy the Technical Specifications requirements for modified secondary containment. Therefore, after appropriate precautions had been tc an to assure personnel and equipment safety, the clearance was authorized for removal, equipment tags were removed, and the air supply valves were reopened. At 1120 CDT, upon restoring drywell instrument air nressure, the reactor vessel head vent valves were reopened, and the Technical apecifications requirement (i.e., to vent the reactor vessel when modified secondcry containment is in effect) was satisfied.

On 5/21/90, at 0135 CDT, in accordance with the ouu3 ark plan, normal secondary containment was established for Unit 1, thus eliminati; ;he requirement to vent the l l RCS. '

l

\

CAUSE OF THE EVENT The root causes of this was cognitive personnel error. The licensed Shift Supervisor who authorized the clearance did not realize the reactor head vent valves were required 'I to remain open to maintain Technical Specification compliance. The valves used to vent the RCS are designed to fail closed on a loss of air. Controls were not in place to ensure a reliable vent path. Further, the requirement to maintain a vent path and the method used to meet that requirement were not covered by procedure, r

l i l

g m. . ..... m i,.. m ..,. m - .

-_x ~

ac *.n., as a u s =ve6ta muutony cowuissio

. UCENSEE EVENT REPORT (LER) TEXT CCNTINUATION cPer.ovio ous =o sino-cion e

IXPIRis t'31 W ,

P ACILif Y haast tip Dockti NvMD6R LI) gga Nuutta 131 PA06 (3) vi.= "= W.T:

PLANT HATCH, UNIT 1 f(KT (# mere apoco # soeurcef, see sehustraf 44C Pome W W (178 o ls j o l o l o l 3 l 2l 1 9l0 -

0l0l8 -

0l0 0l4 0F 0 15 REPORTABILITY ANALYSIS AND SAFETY ASSESSMENT This event is reportable per 10 CFR 50.73 (a)(2)(1)(B) because an event occurred in which Unit 1 entered a condition prohibited by the plant's Technical Specifications.

Specifically, Unit 1 Technical Specifications section 3.7 C.2.a(2) requires that the reactor vessel be vented at all times during periods when modified secondary containment is in effect. When the vent valves closed, this condition was not satisfied.

The purpose of secondary containment is to minimize potential ground level radioactive releases which might result from a serious accident. During conditions of modified '

secondary containment, it is assumed that the only accident which could occur is a refueling accident. Thus when modified secondary containment is in effect per Unit 1  ;

Technical Specifications section 3.7.C. the secondary containment structure for Unit 1 '

consists of the refueling floor only. The secondary containment structure for Unit 2 consists of the Unit 2 reactor building. To preserve the assumptions implicit in the modified secondary containment provision, certain restrictions are placed on the configuration of Unit 1, including maintaining a specified shutdown margin, maintaining reactor coolant temperature below 212'F, venting the reactor vessel, and maintaining specified damper, valve, hatch and door alignments. These restrictions assure that the reactor coolant system cannot be pressurized and that any potential radioactive release occurring on the refueling floor will be contained there with proper response by the Standby Gas Treatment System (EIIS Code BH).

I In the event addressed in this report, one of the requisite conditions for allowing the use of modified secondary containment for Unit 1 was not satisfied. Specifically, the t requirement to keep the reactor vessel vented at all times was not met because plant ,

design and lack of procedural guidance allowed the RCS vent valves to close. During the period of approximately 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> in which the condition existed, the reactor coolant temperature of Unit 1 was kept well below 212'F, no rise in reactor vessel pressure was observed, and no degradation of secondary containment boundaries pertaining to either unit occurred.

Based on the above analysis, it is concluded that this event had no adverso impact on nuclear safety. This analysis applies only to plant conditions under which the use of modified secondary containment is allowed.

CORRECTIVE ACTIONS i

Imediate corrective actions taken for this event included removing equipment clearance 1-90-1111, and reopening the reactor vessel head vent valves to satisfy the requirements of Unit 1 Technical Specifications section 3.7.C.2.a(2), l i

Corrective actions to prevent recurrence include counseling the responsible Shift i Supervisor and:

1. Determining a more reliable method of venting the reactor coolant system during an  !

outage when modified secondary containment is in effect and, j l

ge,o= m. ..... - .....m -

wxc seem smaa

'*"' ua NuctsAn atoukatomy comutteion LICENSEE EVENT REPORT (LER) TEXT CONTINUATION ***aovio ove so sino-c*

IKPIRES. t'31/98 ti.citety haut tu Dixm4Thevestth til Lim Nuutta (86 Pact t3l saa " R= '." 0'#3:

PLANT HATCH, UNIT 1 1SK1 IN more apen s z, z, une _ . ;knC Fenn Welt 1h o ls l o l o l o l 3 l 2l 1 9l 0 -

0l0l8 -

0IO Ol 5 0F 0 15

2. Including the method and the requirement to maintain the vent path in plant procedures. These actions will be completed by the start of the next Unit 1 refueling outage presently scheduled for September 1991. j-ADDITIONAL INFORMATION '

1. Previous Similar Events:

An equipment clearance resulting in the plant entering a conditio',1 prohibited by -

Technical Specifications was reported in LER 50-321/1989-013, dat.ed 10/31/89.

Corrective actions for that event included remedial action to bring the plant to a state the of conformance involved personnel.withThose the Technical Specifications requirements and counseling corrective actions would not have prevented this event because the personnel involved and the action taken to bring the plant into conformance were both unique to that event. -

2. Failed Components Identification:

No failed components contributed to this event. )

3. Other Affected Equipment:

No systems other than those mentioned in this report were affected by the event.

m

.,;,o.. .e ..... m , i,... m -,..,. m