ML18096A220

LER 91-007-01:on 910217,motor-driven Auxiliary Feedwater Pumps Started After 125-volt Dc Distribution Cabinet Power Supply Transferred to Emergency Power.Caused by Inadequate Administrative Controls.Schematics reviewed.W/910815 Ltr

ML18096A220
Person / Time
Site:	Salem
Issue date:	08/15/1991
From:	Pollack M, Vondra C Public Service Enterprise Group
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-91-007-01, LER-91-7-1, NUDOCS 9108260040
Download: ML18096A220 (4)

Text

. e PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station August 15, 1991 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555

Dear Sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 SUPPLEMENTAL LICENSEE EVENT REPORT 91-007-01 This Supplemental Licensee Event Report is being submitted pursuant to 10CFR50.73. This supplement enhances the analysis of the event as requested by NRC Inspection Report 272/91-05.

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NRC FORM 366 (6.89)

LICENSEE EVENT REPORT (LERI U.S. NUCLEAR REGULATORY COMMISSION

- APPROVED OMB NO. 3150-0104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE I

OF MANAGEMENT AND BUDGET, WASHINGTON, DC 20503.

FACILITY NAME (11 DOCKET NUMBER (2) PAGE (3 Sal~m TITLE (41 Generating Statiop - Unit 1 o 1s 1 o Io I o I 2 17 12 1 loF 0 13 ESF Actuation: Auto Start OF Aux Feedwater Pumps Due To Inad. Admin. Controls EVENT DATE (5) LER NUMBER (6) REPORT DATE (71 OTHER FACILITIES INVOLVED (Bl MONTH DAY YEAR YEAR )( SEQUENTIAL NUMBER nn REVISION NUMBER MONTH DAY YEAR FACILITY NAMES DOCKET NUMBER(S) o1s1010101 I I I7 - -

012 1 9 1 9 11 01 017 011 01 8 1 I5 911 0151010101 I I OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE R~OUIREMENTS OF 10 CFR §: (Chock one or more of the following} (11)

MODE (9) 5 20.402(b)

,__ 20.405(c) IX 60.73(o)(2)(iv) 73.71(b) 1- 1--

I010 20.406(a)(1 l(i) 60.36(c)(1) 50.73(o)(21M 73.71(c)

POWER o.__ ....__ ....__

LEVEL (10) I 20.405(*)(1 )(ii) 50,38(c)(2) 50.73(o)(2) (vii)

- OTHER (S~cify in Abstrscr below and in Tsxt, NRC Form l!llilf~l~~'j1f 20.405{a)(1 )(iii) 50,73(o)(2)(i) 60.73(*1 (2)(vili)(Al 366AI Jiil -

20.405 (a) (11 (iv) 20.406(*)(1 )(vi 50,73(o)(2)(ii) 50.73(o)(2)(iii)

LICENSEE CONTACT FOR THIS LER (12)

-- 60.73(o)(2)(viii) (Bl 50.73(0)(2)(*)

NAME TELEPHONE NUMBER AREA CODE M. J. 'Pollack - LER Coordinator 6 I 0 19 13 19 I -12 I 01212 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131

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MANUFAC- REPORT AB LE i:-::-:- ::::::: ::::::  :-:-  :-:-: MANUFAC- REPORTABLE CAUSE SYSTEM COMPONENT TO NPRDS [,'- -:-:  :-:*  :;::: CAUSE SYSTEM COMPONENT TUR ER -:-:* TUR ER TO NPRDS  :.1::-..-*:::.:-:,:::*_.::,::**:*,::::,:::::.i:*.::.:

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I I I I I I I i;.;.-.;.;.;.:  ::::::- -:-:-:-: :-::::: *:*:-:-: I I I I I I I  :::: (? ?/ :::::::: SUPPLEMENTAL REPORT EXPECTED 114) MONTH DAY YEAR EXPECTED

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SUBMISSION n YES (If yes, comp/ere EXPECTED SUBMISSION DATE/ NO DATE 1151 I I I ABSTRACT (Limit to 1400 spsces, i.e., approximately fifte~n single-space typewritten lines) (161 On 2/17/91 at 2200 hours, the Motor Driven Auxiliary Feedwater (MDAFW) Pumps automatically started after the lCCDC 125 VDC Distribution Cabinet power supply was transferred to its emergency power supply in preparation for a lC 125VDC Bus outage. The Unit's 9th refueling outage was- in progress when this event occurred. The automatic start of the MDAFW Pumps is an engineered safety feature (ESF) actuation. Investigation into the root cause of this event is attributed to inadequate administrative controls. To support removal of a DC Distribution Cabinet from service, operations procedure IV-5.3.3, "DC Breaker - Administrative Control" is used in conjunction with schematics- and the Tagging Request Information System. The procedure is used to identify DC breakers. It does not detail the steps necessary to remove DC Buss es from service. Subsequently, the auto start capability of the MDAFW Pumps (on a "loss of both Steam Generator Feedwater Pumps" signal) was not recognized as possibly occurri_ng prior to removing the lCCDC 125VDC Distribution Cabinet from service. This signal will automatically be initiated, upon changing the power supply to the Distribution Cabinet, due to relay deenergization and subsequent reenergization, unless applicable equipment is removed from service (tagged out) . A review of electrical schematics was conducted to identify the cause of the event. New procedures will be developed to detail the steps required in support of removal of DC Distribution Cabinets from service. In the interim, Operations Procedure IV-5.3.3 has been revised to prevent event recurrence. I NRC Form 366 (6.89)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit.1 5000272 91-007-01 2 of 3 PLANT AND SYSTEM IDENTIFICATION: Westinghouse * - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in the text *as (xxl IDENTIFICATION OF OCCURRENCE: Engineered Safety Feature Actuation: Automatic start of the Motor Driven Auxiliary Feedwater Pumps due to inadequate administrative controls Event Date: 2/17/91 Report Date: 8/15/91 This report was iniiiated by Incident Report No. 91-106. CONDITIONS PRIOR TO OCCURRENCE: Mode 5 (Cold Shutdown): 9th Refueling Outage (outage initiated on 2/9/91); RCS drain down to 104' level, in progress DESCRIPTION OF OCCURRENCE: On February 17, 1991, at 2200 hours, the Motor Driven Auxiliary Feedwater (MDAFW) Pumps {BAI automatically started after the lCCDC 125VDC.Distribution Cabinet {EJI power supply was transferred to its emergency power supply in preparation for a lC l25VDC Bus outage. The Unit's 9th refueling outage was in progress when this event occurred. The automatic start of the MDAFW Pumps is an engineered safety feature (ESF} {JEI -actuation. Therefore, this event was reported to the Nuclear Regulatory Commission in accordance with Code of Federal Regulations 10CFR 50.72(b) (2) (ii) on February 18, 1991 at 0058 hours. APPARENT CAUSE OF OCCURRENCE: The root cause of this event is attributed to inadequate administrative controls. To support removal of a DC Distribution Cabinet from service, operations procedure IV-5.3.3, "DC Breaker - Administrative Control" is used in conjunction with schematics and the Tagging Request Information System (TRIS) . The procedure *is used to identify DC. breakers. It does not detail the steps necessary to remove DC Busses from service. Subsequently, the auto start capability of the MDAFW Pumps (on a "loss of both Steam Generator Feedwater Pumps" signal) was not recognized as possibly occurring prior to removing the lCCDC 125VDC Distribution Cabinet from service. *This signal will automatically be initiated, upon changing the power supply to the Distribution Cabinet, due to relay de-energization and subsequent

LICENSEE EVENT REPORT {LER) TEXT CONTINUATION

  '* Salem Generating Station        DOCKET NUMBER     LER NUMBER         PAGE Unit 1                            5000272         91-007-01        3 of 3 APPARENT CAUSE OF OCCURRENCE:

re-energization, unless applicable* equipment is removed from service (tagged out). ANALYSIS OF OCCURRENCE: The Auxiliary Feedwater System consists of two (2) MDAFW pumps, one (1) steam driven auxiliary feedwater pump and associated valves and p1p1ng. It is required to be operable in Modes 1 (Power Operation), 2 (Critical), and 3 (Hot Standby). The system is designed to cooldown the Reactor Coolant System {RCS) {ABI to less than ~50°F from normal operating conditions in the event of a total loss of off-site power. At less than 350°F, the Residual Heat Removal {RHR) System is used to remove ~xcess RCS heat. Each MDAFW pump can provide 50% of required flow to the Steam Generators. The steam driven pump will provide 100% of required flow. At the time of this event, the Unit was in Mode 5. The four (4) Steam Generator Auxiliary Feedwater Control valves (AF21s) were closed. Valve demand*was at zero. This was in support of preparations for Steam Generator work. When the MDAFW Pumps started, their flow was directed to their respective recirculation lines. The pumps were stopped immediately after they were started. As stated above, the AFW System is not used to support RCS heat removal in this mode. Also, Steam Generator level was not affected by this event. Therefore, the automatic start of the MDAFW Pumps did not affect the health or safety of the public. However, since this function is an ESF function, this event is reportable to the Nuclear Regulatory Commission in accordance with Code of Federal Regulations 10CFR50. 73 {a) (2) {iv). CORRECTIVE ACTION: A review of electrical schematics was conducted to identify the cause . of the event. New procedures will be developed to detail the steps required in support of removal of DC Distribution Cabinets from service. In the interim, Operations Procedure IV-5.3.3 was revised to include steps to prevent the inadvertent auto start of the MDAFW Pumps. The pumps are now required to be cleared and tagged prior to de-energizing the lC 125 VDC powered bus.

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General Manager - J7c.-i_..... Salem Operations MJP:pc SORC Mtg. 91-084}}