ML20029D849

LER 94-006-00:on 940407,plant Did Not Meet Requirements of LCO 3.7.6.1 Re Two Independent Control Room Emergency Ventilation Sys.Caused by Inadequate Work Organization. Corrective Action:Revised OP 2315A.W/940502 Ltr

ML20029D849
Person / Time
Site:	Millstone
Issue date:	05/02/1994
From:	Lutzi P, Miller D NORTHEAST NUCLEAR ENERGY CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-94-006-01, LER-94-6-1, MP-94-298, NUDOCS 9405100220
Download: ML20029D849 (4)

Text

_ _ _ - - _ _ - _ _ - - - _ _ _ _

I l

. i 1 Northeast Rope Ferry Rd. (Route 156), Waterford, CT 06385 g@ N'u clear Energ Millstone Nuclear Power Station I Northeast Nuclear Energy Company i P.O. Box 128 l Waterford, CT 06385-0128 (203) 444 - 4300 Fax (203) 444-4277 The Northeast Utilities System Donald B. Miller Jr.,

Senior Vice President - Millstone Re: 10CFR50.73 l May 2, 1994 )

MP-94-298 j l

U.S. Nuclear Regulatory Commission i Document Control Desk Washington, D.C. 20555

Reference:

Facility Operating License No. DPR-65 Docket No. 50-336 Licensee E ant Report 94-006-00 Gentlemen:

This letter forwards Licensee Event Report 94-006-00 required to be submitted within thirty (30) days pursuant to 10CFR50.73(a)(2)(i).

Very truly yours, NORTHEAST NUCLEAR ENERGY MPAN A.

Donald B. Miller, Jr.

Senior Vice President - Millstone Station DBM/SJS:dir

Attachment:

LER 94-006-00 cc: T. T. Martin, Region i Administrator R D. Swetland, Senior Resident Inspector, Millstone Unit Nos.1,2 and 3 G. S. Vissing, NRC Project Manager, Millstone Unit No. 2 100043

[/ h d? b db'3 h' I

4o31oo22o 940502 gDR g ADOCK 05000336 PT@FM

_ . . __ ._ m___ _ _ . ._~ _ _ _ __

NRC Form 366 U.S. NUCLEAR REGULATORY COMM:SSION APPROtfED BY OMB NO. 3150-0104

, (5-90) EXPlRES

5/31/93 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTTH THIS INFORMATION COLLECTION REOUEST 50 0 HRS FORWARD COMMENTS REGARDING BURDEN ESwAn Tm iNFORuAmN AND RECORDS uANAGeueNT i LICENSEE EVENT REPORT (sLER) BRANCH (MNBB 7714). U.S NUCLEAR REGULATORY COMMISSION, WASHINGTON. DC 20556-0001, AND TO THE PAPERWORK REDUCTION y

PROJECT (3150 - 0104), OFFICE OF MANAGEMENT AND BUDGET.

ISee toverse for required number of digrts/characteas for each bloCN) WASHINGTON. DC 20503 FACILITY NAME (1) DOCKET NUMBER (2) PAGE (3)

Millstone Nuclear Power Station Unit 2 05000336 1 OF 3

, TITLE (4) j Entered L-30A to Grease Motor Bearings of F32A l EVENT DATE (5) LER NUMBER (6) REPORT DATE (7) OTHER FACILITIES INVOLVED (8)

SE R S FACluTY NAME DOChET NUMBER MONTH DAY YEAR YEAR MONTH DAY YEAR

! 05000 05 02 94

> 04 07 94 94 - 006 - 00 05000 3

1 OPERATING THIS REPORT IS BEING SUBMITTED PURSUANT TO THE REOUIREMENTS OF 10 CFR i: (Check One Or mOre) (11) 20 402(b) 20 405lc1 50 73(ax2)ov) 73 71(b)

POWER 20 405ta)(110) 50.36:c)(1) 50 73:a:(2)M 73 71(c) 20 405taH11(lil 50 36teH2) 50 73;aM2)MI) OTHER 20 405(a)(1)(ill) X S 73;a:c2)(i) 50 73(a)(2)<viiinA) (Spectiyin Ao.traci t' vow and in Text, NRC 20 405ta)(1)(tv1 50 73(a)(2)(11) 50 73(a)(2)Mll)(B) Form 366A) l 20 405taH11M 50 73:a)(2 Hill) 50 736aH2)fxi

) LICENSEE CONTACT FOR THIS LER (12)

NAME WLFPHONE NUMBER finclude Area Codel l

l Philip J. Lutzi, Site Licensing (203) 444-1791 Ext.' 6585 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) l REPORTAP,LE REPORTABLE CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS CAUSE SYSTEM COMPONENT MANUFACTURER TO NPRDS d

4 i

"U" " ## #"

j SUPPLEMENTAL REPORT EXPECTED (14) EXPECTED a YES NO SUBMISSION 5 Of yes. temprate EXPECTED SUBMISSION DATE) X 0 ATE (15) f ABSTRACT (umn to 1400 spaces,1 e apprommawy is smgie-spaced typeemen imes) (16) i l At 1100 on April 7,1994, with the plant in MODE 1, it was determined that the plant did not meet the requirements of LCO 3.7.6.1, requiring two independent control room emergency ventilation systems. As a result, Technical

Specification 3.0.3 was entered. The unit was in Technical Specification Action Statement (TSAS) 3.7.6.1 for

maintenance to be performed on the "A" Control Room Air Conditioning (CRAC) System Filter Fan (F32A). The "A" I and "B" CRAC Filter Fans share a common suction plenum. Opening either filter housing door effectively

! breaches the Control Room Air Conditioning Filtration boundary rendering both trains of CRAC INOPERABLE.

] The filter housing door was opened to perform maintenance without a dedicated operator as required by plant j procedures. The unit logged out of Technical Specification 3.0.3 at 1110, April 7,1994.

i i

b W

i-r t

4 NRC Form 366 {5+92) 4 1

I

, , . _ _ - . ~ , .

- -. - -. .- - . - - - . - - . - _- - - - - - . - ~.-

[ .

U.s. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB No. 3150-0104 NQC (5 92)Form 366A EXPIRES:5/31/95 l

LICENSEE EVENT REPORT (LER) EEc'r'!JT*4'r"f!M'

' rom c7JNN"I$"S$  ;

TEXT CONTINUATION BE

"" c" **ENEmT*S"'Nu"^tE EoEv' "^S's5'o$

) too o 04 O CE F GE NT AND BUD WASHINGTON DC 20503.

i FACRJTY NAME (1) DOCKET NUMBER (2) LER NUMBER (61 PAGE (31 YEAR W yy Millstone Nuclear Power Station Unit 2 05000336 94 - 006 - 00 02 OF 03

TEXT (n more space e reauneo. use additonal copies of NRO Form 366A) (17) j l. Descriotion of Event At 1100 on April 7,1994, with the plant in MODE 1, it was determined that the plant did not meet the

- requirements of LCO 3.7.6.1, requiring two independent control room emergency ventilation systems. As i a result, Technical Specification 3.0.3 was entered.

l The control room air conditioning system consists of two full capacity, independent air handling and mechanical refrigeration subsystems. Each subsystem is provided with a bypass through the control room i filtration system (CRFS) consisting of particulate, HEPA and charcoal filters (L30A/L308) and filter fans  ;

! (F32A/F328). The unit was in Technical Specification Action Statement (TSAS) 3.7.6.1 for maintenance to

' be perform on the "A" Control Room Air Conditioning (CRAC) System Filter Fan (F32A). The *A" and "B"

} CRAC filter fans are enclosed within a separate filter housing (L30AA308) that share a common suction plenum. Opening either filter housing door effectively breaches the CRAC filtration boundary and results in

both trains of CRAC being INOPERABLE.

I 1 At the time of the event, the Operations Department had authorized a work order to grease "A" CPAC Filter i Fan (F32A) motor bearings (Facility 1). The Automated Work Order contained a CAUTION: "Do Nd Ooen

. Quetwork Un@r This AWO.* The technicians working the job noted the caution but felt that opening the

filter housing door did not constitute opening ductwork. The plant operator obtained the key to the f iter 1 housing (L30A) and opened the locked closed door to allow the technicians to perform their task. Tne i plant operator returned to the control room and notified the Senior Control Operator (SCO) in charge of

! Work Control. No provision was established to shut the housing door by utilizing a dedicated operator. At .

- that time, the SCO concluded that with the door open, both trains of Control Room Air Conditioning were

• j INOPERABLE due to a common suction plenum. The plant operator was immediately sent back to the work site to close the filter door. By this time the technicians had finished their task and the door was

! closed. The plant operator locked the door access. The total elapsed time which the door was open was

, determined to be ten minutes or less. Ten minutes is the time allowed by procedure for a dedicated j operator to ensure that the door is closed in the event of an accident requiring the CRAC System to j automatically align to the recirculation me ?s.

t There were no automatic or manual safety system actuations as a result of this event.

j 11. Capse of Event The root cause of this event was inadequate work organization and planning which resulted in a

! misunderstanding of the requirements of a dedicated operatorin attendance. Although the unit has I

provisions for operator in attendance to address the need for system maintenance, this requirement was inadvertently omitted during "A" filter fan maintenance.

i 111. Analysis of Event i

This report is being submitted pursuant to the requirements of 10CFR50.73(a)(2)(i)(B), "Any operation or condition prohibited by the plant's Technical Specification." There were no safety consequences resulting j from this event since the filter housing door was closed within the amount of time,10 minutes, assumed in j the system analysis for the manualinitiation of CRAC recirculation mode (FSAR 9.9.10.4.1).

IV. Corrective Action l

Operations Procedure OP 2315A has been revised to describe the opening of ventilation doors or covers affecting control room ventilation system. Work orders for maintenance on these systems have been j modil'ed to required a dedicated operatoi in attendance for system maintenance.

4 J

NRC Form 366A (5-92) 5 4

c,- m- ,

-, ._ - - .-..c ,. - - - , , . ,e. - ., m w, r, w

l

• WSC Form 366A

. U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMB NO. 3150-0104 (5-92) EXPIRES: 5/31/95 LICENSEE EVENT REPORT (LER) CEST8 N k" 't5"E'I "s ?cA "J8CEPNis"Re""# *

. BURDEN ESTIMATE TO THE INFORMATION AND RECORDS MANAGEMENT TEXT CONTINUATION sRANCN paNsa rri4i. us. NuctEAR ReoVLATORY COMMISSION.

WASHINGTON. DC 20556- 0001 AND TO THE PAPERWORK REDUCTION PROJECT Q150-0104), OFFCE OF MANAGEMENT AND BUDGET.

WASHINGTON, DC 20503 FACRJTY NAME (1) DOCKET NUMBER (2) LER NUMBER (@ PAGE '31 i I

YEAR SE,0, g9W R S u

Millstone Nuclear Power Station Unit 2 05000336 94 -

006 - 00 03 OF 03 TEXT (ti more space a required. use addmore copies of NRC Form 366A) (17)

V. Additional information Ells Codes VI (Control Room Air Conditioning System)

Similar LERs: NONE 1

l l

NHC Form 366A (5-92) l l

l

, _ . ,_