05000244/LER-1996-011, :on 960807,improper Configuration of Circuit Breaker Occurred,Due to Undetected Internal Interference, Resulting in Automatic Start of Both Auxiliary Feedwater Pumps.Running AFW Pumps Were Secured

:on 960807,improper Configuration of Circuit Breaker Occurred,Due to Undetected Internal Interference, Resulting in Automatic Start of Both Auxiliary Feedwater Pumps.Running AFW Pumps Were Secured

ML17264A591
Person / Time
Site:	Ginna
Issue date:	09/05/1996
From:	Martin J, Mercredy R ROCHESTER GAS & ELECTRIC CORP.
To:	Vissing G NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-96-011, LER-96-11, NUDOCS 9609130028
Download: ML17264A591 (8)

LER-1996-011, on 960807,improper Configuration of Circuit Breaker Occurred,Due to Undetected Internal Interference, Resulting in Automatic Start of Both Auxiliary Feedwater Pumps.Running AFW Pumps Were Secured

Event date:
Report date:
Reporting criterion:	10 CFR 50.73(a)(2)(i) 10 CFR 50.73(a)(2)(ii) 10 CFR 50.73(a)(2)(iii) 10 CFR 50.73(a)(2)(iv), System Actuation 10 CFR 50.73(a)(2)(v), Loss of Safety Function 10 CFR 50.73(a)(2)(vii), Common Cause Inoperability 10 CFR 50.73(a)(2)(viii) 10 CFR 50.73(a)(2)(x)
2441996011R00 - NRC Website

text

('A'19'(90RY j REGULA RY INFORMATION DISTRIBUTI SYSTEM (RIDS) 1 ACCESSION NBR:9609130028 DOC.DATE: 96/09/05 NOTARIZED:

NO DOCKET FACIL:50-244 Robert Emmet Ginna Nuclear Plant, Unit 1, Rochester G

05000244 AUTH.NAME AUTHOR AFFILIATION MARTIN,J.T.

Rochester Gas

& Electric Corp.

MERCREDY,R.C.

Rochester Gas a Electric Corp.

RECIP.NAME RECIPIENT AFFILIATION VISSINGiG.S.

SUBJECT:

LER 96-011-00:on 960807,improper configuration of circuit breaker occurred.Due to undetected internal interference, resulting in automatic start of both auxiliary feedwater pumps. Running AFW pumps were secured.W/960905 ltr.

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TITLE: 50.73/50.9 Licensee Event Report (LER), incident Rpt, etc.

NOTES:License Exp date in accordance with 10CFR2,2.109(9/19/72).

05000244 E

RECIPIENT ID CODE/NAME PD1-1 PD INTERNAL:

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AREA CODE7165d62700 ROScRT C. MECREDY Vce President Nvctear Ooerrst'or s September 5, 1996 U.S. Nuclear Regulatory Commission Document Control Desk Attn:

Guy S. Vissing Project Directorate I-1 Washington, D.C. 20555

Subject:

LER 96-011, Improper Configuration of Circuit Breaker, Due to Undetected Internal Interference, Results in Automatic Start of Both Auxiliary Feedwater Pumps R.E. Ginna Nuclear Power Plant Docket No. 50-244

Dear Mr. Vissing:

In accordance with 10 CFR 50.73, Licensee Event Report System, item (a) (2) (iv), which requires a report of, "Any event or condition that resulted in a manual or automatic actuation of any engineered safety feature (ESF), including the reactor protection system (RPS)", the attached Licensee Event Report LER 96-011 is hereby submitted.

Th!s event has in no way affected the public's health and safety.

Very truly yours, Robert C. Mecredy xc:

Mr. Guy S. Vissing (Mail Stop 14C7)

PWR Project Directorate I-1 Washington, D.C.

20555 U.S. Nuclear Regulatory Commission Region I 475 Allendale Road King of Prussia, PA 19406 Ginna Senior Resident Inspector c7609i30028 960905 PDR aOOCK 05000 44 S

PDR

NRC FORM 366 (4-95)

U.S. NUCLEAR REGULATORY COMMISSIO LICENSEE EVENT REPORT (LER)

(See reverse for required number of digits/characters fcr each block)

APPROVED BY OMB NO. 3160%104 EXPIRES 04/30/98 ESTIMATED BURDEN PER

RESPONSE

To COMPLY WITH THIS MANDATORY INFORMATION COLLECTION REQUEST: 50.0 HRS.

REPORTED LESSONS LEARNED ARE INCORPORATED INTO THE LICENSING PROCESS AND FED BACK To INDUSTRY.

FORWARD COMMENTS REGARDING BURDEN ESTIMATE To THE INFORMATION AND RECORDS MANAGEMENT BRANCH (T-6 F33),

U.S. NUCI.EAR REGULATORY COMMISSION, WASHINGTON, DC 20555 cool, AND TO THE PAPERWORK REDUCTION PROJECT FACIUTYNAMEIII R.E. Ginna Nuclear Power Plant DOCKET NUMBERI2) 05000244 PAOE I3) 1OF5 TITLE(4I Improper Configuration of Circuit Breaker, Due to Undetected Internal Interference, Results in Automatic Start of Both Auxiliary Feedwater Pumps EVENT DATE (6)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIES INVOLVED(8)

MONTH 08 DAY 07 YEAR 96 SEQUENTIAL REVISION NUMBER NUMBER 96 011 00 MONTH OAY 09 05 96 FACIUTYNAME FACIUTYNAME DOCKET NUMBER DOCKET NUMBER OPERATING MODE (9)

POWER LEVEL (10) 000 20.2201(b) 20.2203(a) (1) 20.2203(a)(2)(i) 20.2203(a)(2)(ii) 20.2203(a)(2) (iii) 20.2203(a) (2) (iv) 20.2203(a) (2) (v) 20.2203(a) (3) (i) 20.2203(a)(3) (ii) 20.2203(a) (4) 50.36(c)(1) 50.36(c)(2) 50.73(a) (2)(i) 50.73(a)(2) (ii) 50.73(a) (2) (iii)

X 50.73(a)(2)(iv) 50.73(a)(2)(v) 50.73(a)(2)(vii)

THIS REPORT IS SUBMITTED PUR SUANT TO THE REQUIREMENTS OF 10 CFR %: (Check one or more)

(11) 50.73(a) (2)(viii) 50.73(a)(2) (x) 73.71 OTHER Specify in Abstract below or m NRC Form 366A NAME LICENSEE CONTACT FOR THIS LER (12)

ELEFHONE NUMBER ilncrvde Area Codel John T. St. Martin - Technical Assistant COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESC (716) 771-3641 RIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPONENT MANUFACTURER To NPRDS

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE To NPROS SUPPLEMENTAL REPORT EXPECTED (14)

YES (If yes, complete EXPECTED SUBMISSION DATE).

X NO EXPECTED SUBMISSION DATE (16)

MONTH DAY YEAR ABSTRACT (Limitto 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On August 7, 1996, at approximately 2009 EDST, the plant was in IVlode 3 with the reactor coolant system being maintained at a temperature of 545 degrees F and a pressurizer pressure of 2235 PSIG.

With no auxiliary feedwater pumps running and one main feedwater pump circuit breaker racked out in the "test" position,'n "AFW Bypass Switch" was moved from "Defeat" to "Normal". An undetected improper configuration of the circuit breaker created the logic that both main feedwater pump breakers were already open.

This created the logic for autostart of both the "A" and "B" motor-driven auxiliary feedwater pumps.

Immediate action was to stabilize auxiliary feedwater flow to both steam generators.

The underlying cause of the autostart was that the logic for autostart divas present due to an undetected internal interference within the circuit breaker between the racking arm and the actuating rod for the 52S auxiliary switch, which prevented this switch from opening to provide the circuit logic that the breaker was in the closed position.

This event is NUREG-1022 Cause Code (A).

Corrective action to prevent recurrence is outlined in Section V.B.

NRC FORM 366 (4-95)(4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME (1)

R.E. Ginna Nuclear Power Plant DOCKET 05000244 LER NUMBER (6)

YEAR SEQUENTIAL REVISION NUMBER NUMBER 96

011

00 PAGE (3) 2 OF 5

TEXT iifmore speceis required, use edditionef copies of NRC Form 366Aj (17)

PRE-EVENT PLANT CONDITIONS:

On August 7, 1996, at approximately 2009 EDST, the plant was in Mode 3 as a result of a voluntary plant shutdown to upgrade motor-operated valves in the residual heat removal IRHR) system.

Valve upgrades were completed and plant heatup and startup was in progress.

The reactor coolant system IRCS) was being maintained at a temperature of approximately 545 degrees F and a pressurizer (PRZR) pressure of approximately 2235 PSIG.

The circuit breaker for the "A" main feedwater IMFW) pump had jumpers installed and was closed in the "test" position, to comply with temporary administrative requirements.

Auxiliary feedwater IAFW) pumps had just been secured as directed by these temporary administrative requirements, so there were no AFW pumps running.

II.

DESCRIPTION OF EVENT

A.

DATES AND APPROXIMATE TIMES OF MAJOR OCCURRENCES

o August 7, 1996, 2009 EDST: Event date and time.

o August 7, 1996, 2009 EDST: Discovery date and time.

o August 7, 1996, 2024 EDST: One running AFW pump is secured.

o August 7, 1996, 2135 EDST: All running AFW pumps are secured.

EVENT:

On August 7, 1996, at approximately 2009 EDST, the plant was in Mode 3. The RCS was being maintained at a temperature of approximately 545 degrees F

and a

PRZR pressure of approximately 2235 PSIG. As directed by Normal Operating Procedure 0-1.2, "Plant Startup From Hot Shutdown to Full Load", the Control Room operators moved an "AFW Bypass Switch" from the "Defeat" to the "Normal" position. Due to an undetected improper configuration of the circuit breaker for the "A"MFW pump, the 2 of 2 logic for both MFW pump breakers open was present, which caused an autostart of both the "A" and "B" AFW pumps.

The Control Room operators observed the autostart of both the "A" and "B" AFW pumps, and controlled AFW flow to the desired flow rate for Mode 3 conditions.

One of the running AFW pumps was secured at approximately 2024 EDST.

The Control Room operators requested that plant electricians investigate the problem.

Electricians determined, when racking out the circuit breaker into the "test" position, the breaker positioning arm had travelled beyond its mechanical stop.

This caused an undetected interference between the racking arm and the 52S auxiliary switch actuating rod, which prevented the 52S switch from opening to provide circuit logic that the breaker was in the closed position.

The breaker was properly racked out, and electricians verified there was no interference and that the 52S switch had opened.

NIIC FOAM 366A (4-95)

tl(4-95)

LICENSEE EXTENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME (1)

R.E. Ginna Nuclear Power Plant DOCKET 05000244 LER NUMBER (6)

YEAR SEQUENTIAL REVISION NUMBER NUMBER 96

011

00 PAGE (3) 3 OF 5

TEXT (Ifmore spece is required, use eddi donel copies ofNRC Form 366AJ (17)

C.

INOPERABLE STRUCTURES, COMPONENTS, OR SYSTEMS THATCONTRIBUTEDTO THE EVENT:

None D.

OTHER SYSTEMS OR SECONDARY FUNCTIONS AFFECTED

None E.

METHOD OF DISCOVERY

This event was immediately apparent when both the "A" and "B" AFW pumps autostarted after the AFW Bypass Switch was placed in the "Normal".position.

OPERATOR ACTION

After both the "A" and "B" AFW pumps autostarted, the Control Room operators took prompt actions to control AFW flow. They requested that the plant electricians determine the cause of the problem.

The Control Room operators subsequently notified higher supervision and notified the NRC per 10CFR50.72 (b) (2) (ii), non-emergency four hour notification, at approximately 2226 EDST on August 7, 1996.

G.

SAFETY SYSTEM RESPONSES:

Both the "A" and "B" AFW pumps autostarted as per design.

CAUSE OF EVENT

A.

IMMEDIATECAUSE:

The immediate cause of the autostart of both the "A" and "B" AFW pumps was the autostart logic, which was satisfied by 52S contacts providing circuit logic that both MFW pump breakers were open and an AFW Bypass Switch in "Normal".

B.

INTERMEDIATECAUSE:

The intermediate cause of autostart logic being satisfied was an undetected improper configuration of the "A"'MFWpump circuit breaker.

NRC FORM 36:6 I's)(4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORYCOMMISSION FACILITYNAME (1)

DOCKET LER NUMBER (6)

PAGE (3)

R.E. Ginna Nuclear Power Plant 05000244 YEAR SEQUENTIAL REVISION NUMBER NUMBER 4

OF 5

96

011

00 TEXT Iifmore space is required, use additional copies ofNRC Form 36@A/ (17)

C.

ROOT CAUSE:

The underlying cause of the improper configuration was an undetected internal interference within the "A" MFW pump circuit breaker.

When the breaker was racked out to the test position, the breaker positioning arm travelled beyond its mechanical stop.

This caused interference between the racking arm and the actuating rod for the 52S auxiliary contact switch. Therefore, while the breaker was physically closed in the "test" position, the auxiliary switch did not provide circuit logic that the breaker was in the closed position.

This situation was created to be in compliance with the Ginna Station Improved Technical Specifications (ITS) Table 3.3.2-1 Function 6.f. To prevent an unnecessary actuation of both AFW pumps during Mode 2 conditions, a MFW pump breaker may be administratively closed in the test position, provided it is capable of being tripped on undervoltage and overcurrent conditions.

The administrative requirements were established to comply with ITS Table 3.3.2-1, which requires the autostart function of the motor-driven AFW pump upon opening of both MFW pump breakers during Modes 1 and 2. Prior to Amendment No. 61 to the ITS, this function was only required in Mode 1 when the MFW pumps were actually in service.

The addition of Mode 2 (when the MFW pumps may not be in service) was inadvertently added to the ITS by Amendment No. 61.

This event is NUREG-1022 Cause Code (A), "Personnel Error". This error was a cognitive error on the part of a plant electrician, who did not detect the interference between the racking arm and the actuating rod.

This error was associated with activities that were covered by an approved procedure, and was not contrary to that procedure.

The procedural guidance was correct, but enhancements to the procedure have been identified. There were no unusual characteristics of the location of this breaker that contributed to this event.

Note that this interference can only be created when racking the breaker out to the test position.

The autostart of the AFW pump does not meet the NUMARC 93-01, "Industry Guideline for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants",

definition of a

"Maintenance Preventable Functional Failure".

IV.

ANALYSIS OF EVENT

This event is reportable in accordance with 10 CFR 50.73, Licensee Event Report System, item (a) (2) (iv),

which requires a report of, "Anyevent or condition that resulted in a manual or automatic actuation of any engineered safety feature (ESF), including the reactor protection system (RPS)".

The start of an AFW pump is an actuation nf an ESF.

An assessment was performed considering both the safety consequences and implications of this event with the following results and conclusions:

There were no operational or safety consequences or implications attributed to the autostart of both the "A" and "B" AFW pumps because:

o The autostart occurred with acceptable levels in both S/Gs.

AFW flow was controlled to maintain these levels.

NRC FOR)A 366A (4.95)(4-96)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION U.S. NUCLEAR REGULATORY COMMISSION FACILITYNAME(1)

R.E. Ginna Nuclear Power Plant DOCKET 05000244 LER NUMBER (6)

YEAR SEQUENTIAL REVISION NUMBER NUMBER 96

011

00 PAGE (3) 5 OF 5

TEXTllfmore spaceis required, use additional copies ofNRC Form 366A/ (17) o The limiting case for the supply of AFW is the Loss of Feedwater accident at 100'/o power.

The plant condition at the time of this event was less than 5% power.

Based on the above, it can be concluded that the public's health and safety was assured at all times.

V.

CORRECTIVE ACTION

A.

ACTION TAKEN TO RETURN AFFECTED SYSTEMS TO PRE-EVENT NORMALSTATUS:

AFW flow was controlled as desired to maintain S/G level.

o The running AFW pumps were secured.

B.

ACTION TAKEN OR PLANNED TO PREVENT RECURRENCE:

The ITS willbe revised to eliminate the need for having a MFW pump breaker closed in the test position during Mode 2 conditions.

Procedure 0-2.1 will be enhanced to include specifically addressing that the 52S switch actuating rod is in the correct position when the breaker is racked out in the test position.

Vi.

ADDITIONALINFORMATION:

A.

FAILED COMPONENTS:

None B.

PREVIOUS LERs ON SIMILAREVENTS:

A similar LER event historical search was conducted with the following results: No documentation of similar LER events with the same root cause could be identified. However, LERs96-004, 96-008, and 96-010 are similar events with different root causes.

C.

SPECIAL COMfvlENTS:

None NRC FORM 9 "~A (4-95)