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| issue date = 09/10/1992
| issue date = 09/10/1992
| title = LER 92-020-00:on 920817,generator-turbine Trip Occurred Due to Generator Differential & Loss of Field During Reinstallation of Voltage Adjuster.Caused by Design Deficiency.No Corrective Actions warranted.W/920910 Ltr
| title = LER 92-020-00:on 920817,generator-turbine Trip Occurred Due to Generator Differential & Loss of Field During Reinstallation of Voltage Adjuster.Caused by Design Deficiency.No Corrective Actions warranted.W/920910 Ltr
| author name = POLLACK M J, VONDRA C A
| author name = Pollack M, Vondra C
| author affiliation = PUBLIC SERVICE ELECTRIC & GAS CO. OF NEW JERSEY
| author affiliation = PUBLIC SERVICE ELECTRIC & GAS CO. OF NEW JERSEY
| addressee name =  
| addressee name =  
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=Text=
=Text=
{{#Wiki_filter:e Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC 20555  
{{#Wiki_filter:e PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station September 10, *1992 U. S. Nuclear Regulatory Commission Document Control Desk Washington, DC               20555


==Dear Sir:==
==Dear Sir:==
SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 92-020-00 September 10, *1992 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations lOCFR 50.73(a) (2) (iv). This report is required to be issued within thirty (30) days of event discovery.
 
MJP:pc Distribution 180054 9209210050 920910 PDR ADOCK 05000272 . . PDR C. A Vondra Manager -Salem Operations  
SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 LICENSEE EVENT REPORT 92-020-00 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73(a) (2) (iv). This report is required to be issued within thirty (30) days of event discovery.
/r;JJ I /)v I 95*2189 (10M) 12-89 NRC 366 (6-89) U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 EXPIRES: 4/30/92 LICENSEE EVENT REPORT (LER) . 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*530l. U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (3150-01041.
C. A Vondra Gen~ral      Manager -
OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON.
Salem Operations MJP:pc Distribution 180054
DC 20503. FACILITY NAME (11 Salem denerating Station -Unit 1 'DOCKET NUMBER (2_1 .. . I PAGE 13! O I 5 I O I O I O I? I ..., I ., 1 OF n h TITLE 141 Reactor Protection System signal actuation; Turbine Trip due to design. EVENT DATE (5) LEA NUMBER 161 REPORT DATE (71 OTHER FACILITIES INVOLVED 1er MONTH DAY ::::::::::;SEQUENTIAL 1:::::::::
                                                                                        /r;JJ I 9209210050 920910
REVISION YEAR YEAR *:*:*:*:*:*
                                                                                      /)v                 I PDR ADOCK 05000272                                                                  95*2189 (10M) 12-89
NUMBER 1:::::::::
  . ~            .          PDR
NUMBER MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI 01s1010101 I I OPERATING MODE (9) THIS REPORT IS SUBMITTED PURSUANT TO TH_E RhQUIREMENTS OF 10 CFR §:(Chock one or more of th .. fa/lawing)
 
(111 1 20.402(b) 20.405(cl l...X 50.73l*H2llivi 73.71lbl --20.4051*111 Hil *50.36(c)(1) 50)3(ol!2llvl 73.71 (cl ,__ --POWER I LEVEL Q ,__ 1101 I 21 l 20.4051*111 Hill 50.36(cll21 50.73(*)(2) (viii OTHER (Specify in Abstract ---below arid in Text, NRC Fo_rm 20.405(o)(1 lliiil 50.73(o)(2)(i) 50.73(ol(2l(viiil(A) 366AI. , --20.405loll1 Hivl 50.73!oll2Hiil 50,73(o)(2llviiil(BI  
NRC FOFI~~ 366                                                                           U.S. NUCLEAR REGULATORY COMMISSION (6-89)                                                                                                                                                                        APPROVED OMB NO. 3150-0104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS
--20.4051*111 lM 50.73(ol(2lliiil 50,73(ol(2llxl LICENSEE CONTACT FOR THIS LEA (12) NAME TELEPHONE NUMBER AREA CODE M.J. Pollack -LER Coordinator 61 O .19 3 I 3 19 I -12 I O I 2 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 :*:*:*:* .;.;:.* . . *.* *.; .. ;.: CAUSE SYSTEM COMPONENT MANUFAC* REPORTABLE
                                                                                                                                                          *INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) .                                                                                        COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P*530l. U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (3150-01041. OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON. DC 20503.
:::;:::::
FACILITY NAME (11                                                                                                                                                       DOCKET NUMBER (2_1     ..     .       I             PAGE 13!
*:*: :*.* *:*: :*.**.*. TUR ER TO NPRDS .*.* *.* . . *.: *.* .. *.* *:* CAUSE SYSTEM COMPONENT MANUFAC* TUR ER *:*:-:-: :*:-*:-: *:*:-:-*.*.*:
Salem denerating Station - Unit 1                                                                                                                                    O I 5 I O I O I O I? I ..., I .,             1 OF               n h TITLE 141 Reactor Protection System signal actuation; Turbine Trip due to design.
.;.* :-:-:*:* .*.**.* . . *.* I I I I I I I )) *:*-:*: :-:**:* .;.:;.: *:**:-:;.: .... ....  
EVENT DATE (5)                             LEA NUMBER 161                                   REPORT DATE (71                                         OTHER FACILITIES INVOLVED 1er MONTH       DAY                         ::::::::::;SEQUENTIAL 1::::::::: REVISION                               DAY            YEAR                FACILITY NAMES                      DOCKET NUMBERISI YEAR     YEAR   *:*:*:*:*:*   NUMBER 1::::::::: NUMBER MONTH 01s1010101                                   I         I THIS REPORT IS SUBMITTED PURSUANT TO TH_E RhQUIREMENTS OF 10 CFR §:(Chock one or more of th .. fa/lawing) (111 OPERATING MODE (9)            1       20.402(b)                                           20.405(cl
.. ...... I I I I I I I ..... , :::::: -:-::-:-:-:.::::::::*:-:*:-:
                                                                                  -                                                            l...X 50.73l*H2llivi                                 73.71lbl POWER LEVEL I Q            ,__
...... .. ::::r .*:**:*: I I I I I .*.**.* . ........ .*.: I I :::;:::: *.:. I I I I I. I I .,.,;::::::.::::::::<;:::::;:
20.4051*111 Hil                         ,__      *50.36(c)(1)
} *.*. *.* .. *.*.*.**.*;*.*;:*:*:-:.;.:;*;*-:.;.:.;
                                                                                                                                              --      50)3(ol!2llvl
SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR EXPECTED SUBMISSION DATE 1151 _ , YES (If. yes. complete EXPECTED SUBMISSION DATE! h NO I I ABSTRACT fL,(mir to 1400 spaces, i.e., approximately fifteBn single-space type_writtan lines) (16) On 8/17/92, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per design. At the time, the Unit was maintaining 21% reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49%. Prior to the trip the automatic voltage regulator had been declared inoperable.
                                                                                                                                                                                          --        73.71 (cl 1101           I 21 l         20.4051*111 Hill
The generator-turbine trip occurred during the reinstallation of the voltage adjuster.
                                                                                --        50.36(cll21                                               50.73(*)(2) (viii                             OTHER (Specify in Abstract below arid in Text, NRC Fo_rm 20.405(o)(1 lliiil 20.405loll1 Hivl 20.4051*111 lM 50.73(o)(2)(i) 50.73!oll2Hiil 50.73(ol(2lliiil
Station management had decided to delay putting the Unit on line to minimize a plant tiansient, if a problem developed with the voltage regulator repair. The root cause of this event is Investigation of this event revealed that Relay 5-86 (MG-6) initiated the generator-turbine trip. Energization of the relay causes "loss of field" which results in a generator-turbine trip. It is not considered possible for this relay to trip without excitation of the generator.
                                                                                                                                              --    50.73(ol(2l(viiil(A) 50,73(o)(2llviiil(BI 50,73(ol(2llxl 366AI.                                  ,
Physical contact had to have been made during the voltage regulator adjuster installation.
LICENSEE CONTACT FOR THIS LEA (12)
The relay is neither covered nor encased to prevent contact. It is also located very close to the voltage adjuster which was being replaced.
NAME                                                                                                                                                                                     TELEPHONE NUMBER AREA CODE M.J. Pollack - LER Coordinator 61 O.19       3 I 3 19 I - 12 I O I 2 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 MANUFAC*       REPORTABLE                     *:*: :*.*   *:*: :*.**.*.                                               MANUFAC*
The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line *during this evolution.
CAUSE   SYSTEM       COMPONENT TUR ER       TO NPRDS      :::;::::: *:* .*.* *.*.   .*.: *.*..*.*     CAUSE SYSTEM      COMPONENT TUR ER I         I   I   I                 I   I   I                       )) *:*-:*: :-:**:* .;.:;.: *:**:-:;.:
No corrective actions are warranted based on* the circ&#xb5;mstances surrounding this event; however, this event was discussed with those individuals involved.
                                                                                                    .... ....           ........           I         I   I     I           I   I   I
NRC Form 366 (6-891 *I I LICENSEE EVENT REPORT (LER) TEXT CONTINUATION.
::::r       .*.**.*. ........
Salem* Generating station Unit 1 DOCKET NUMBER 5000272* PLANT AND SYSTEM* IDENTIFICATION:
                                                                                                                                                                                                                  .,.,;::::::.::::::::<;:::::;:           }
Westinghouse  
I          I I      I                I  I  I                      :::;::::                                             I          I I        I          I. I    I                        *.*..*.*.*.**.*;*.*;:*:*:-:.;.:;*;*-:.;.:.;
-Pressurized Water Reactor LER NUMBER 92-020-00 . PAGE 2 of 3 Energy Industry Identification System (EIIS) codes are identified in the text as {xx} IDENTIFICATION OF OCCURRENCE:
SUPPLEMENTAL REPORT EXPECTED (141                                                                                                             MONTH           DAY                 YEAR EXPECTED
React6r Protection System actuation; Turbine Trip due to design Event Date: 8/17/92 Report Date: 9/10/92 This. report was initiated by Incident Report No. 92-:-521.
_,       YES (If. yes. complete EXPECTED SUBMISSION DATE!
ABSTRACT fL,(mir to 1400 spaces, i.e., approximately fifteBn single-space type_writtan lines) (16) h                NO SUBMISSION DATE 1151 I                I                *I On 8/17/92, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per                                                                                                                                                                                     I design. At the time, the Unit was maintaining 21% reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49%. Prior to the trip the automatic voltage regulator had been declared inoperable. The generator-turbine trip occurred during the reinstallation of the voltage adjuster.                                                                                                                             Station management had decided to delay putting the Unit on line to minimize a plant tiansient, if a problem developed with the voltage regulator repair. The root cause of this event is "Other"~                                                                                                              Investigation of this event revealed that Relay 5-86 (MG-6) initiated the generator-turbine trip.             Energization of the relay causes "loss of field" which results in a generator-turbine trip. It is not considered possible for this relay to trip without excitation of the generator. Physical contact had to have been made during the voltage regulator adjuster installation. The 5~86 relay is neither covered nor encased to prevent inadv~rtent contact.                   It is also located very close to the voltage adjuster which was being replaced.                                     The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line
    *during this evolution. No corrective actions are warranted based on* the circ&#xb5;mstances surrounding this event; however, this event was discussed with those individuals involved.
NRC Form 366 (6-891
 
                                                                              --,1 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION.
Salem* Generating station       DOCKET NUMBER      LER NUMBER      PAGE Unit 1                             5000272*         92-020-00 . 2 of 3 PLANT AND SYSTEM* IDENTIFICATION:
Westinghouse   - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in the text as {xx}
IDENTIFICATION OF OCCURRENCE:
React6r Protection System sign~l actuation; Turbine Trip due to design Event Date:   8/17/92 Report Date:   9/10/92 This. report was initiated by Incident Report No. 92-:-521.
CONDITIONS PRIOR TO OCCURRENCE:
CONDITIONS PRIOR TO OCCURRENCE:
Mode 1 Reactor Power 21% -Unit Load O MWe DESCRIPTION OF.OCCURRENCE:
Mode 1   Reactor Power 21% - Unit Load O MWe DESCRIPTION OF.OCCURRENCE:
On August 17, 1992, at 1737 hours, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per design. At the time, the Unit was maintaining 21% reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49% (i.e., permissive P-9).
On August 17, 1992, at 1737 hours, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per design. At the time, the Unit was maintaining 21%
to the turbine trip the automatic voltage regulator had been *declared inoperable.
reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49% (i.e.,
Troubleshooting revealed that the voltage adjuster was mechanically binding. The generator-turbine trip occurred during the reinstallation of the voltage adjuster.
permissive P-9).
station management had decided to delay putting the Unit on line to minimize a plant transient, if a problem developed with the voltage regulator repair. A generator-turbine trip is a Reactor Prqtection System {RPS) {JC} function.
      ~rior to the turbine trip the automatic voltage regulator had been
On August 17, 1992, at 1808 hours, this event was reported to the Nuclear Regulatory Commission (NRC) in accordance with Code of Federal Regulations lOCFR 50.72{b) (2) (ii). , ' APPARENT CAUSE OF OCCURRENCE:
    *declared inoperable. Troubleshooting revealed that the voltage adjuster was mechanically binding. The generator-turbine trip occurred during the reinstallation of the voltage adjuster. station management had decided to delay putting the Unit on line to minimize a plant transient, if a problem developed with the voltage regulator repair.
The root cause of this event is "Other" (per NUREG 1022, "Licensee  
A generator-turbine trip is a Reactor Prqtection System {RPS) {JC}
*Event Report Program") . Investigation of this event, by System Engineering, revealed that Relay 5-86 (MG-G) initiated the generator-turbine trip. This relay is triggered by field forcing or over-excitation.
function. On August 17, 1992, at 1808 hours, this event was reported to the Nuclear Regulatory Commission (NRC) in accordance with Code of Federal Regulations 10CFR 50.72{b) (2) (ii).
Energization of --, ._ 1 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 .APPARENT CAUSE OF OCCURRENCE: (cont'd) LER NUMBER 92-020.,...00 PAGE 3 of 3 the.relay causes "loss of field" which results in a trip. It is not considered possible for this relay to trip without excitation of the generator.
APPARENT CAUSE OF OCCURRENCE:
Physical contact had to have been made during the voltage regulator adjuster installation.
The root cause of this event is "Other" (per NUREG 1022, "Licensee
    *Event Report Program") .
Investigation of this event, by System Engineering, revealed that Relay 5-86 (MG-G) initiated the generator-turbine trip. This relay is triggered by field forcing or over-excitation. Energization of
 
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station           DOCKET NUMBER     LER NUMBER       PAGE Unit 1                              5000272          92-020.,...00   3 of 3
.APPARENT CAUSE OF OCCURRENCE:      (cont'd) the.relay causes "loss of field" which results in a ge~erator-turbine trip.     It is not considered possible for this relay to trip without excitation of the generator. Physical contact had to have been made during the voltage regulator adjuster installation.
The 5 ... a6 relay (as well as the other relays in the Voltage Regulator Cubicle) is -neither *covered nor encased to prevent inadvertent.
The 5 ... a6 relay (as well as the other relays in the Voltage Regulator Cubicle) is -neither *covered nor encased to prevent inadvertent.
contact. It is.also located very close to the voltage adjuster which was being replaced.
contact.     It is.also located very close to the voltage adjuster which was being replaced. The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line during this evolution.
The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line during this evolution.
Installation of the voltage adjuster includes two bolts located behind
Installation of the voltage adjuster includes two bolts located behind -the adjuster.
      -the adjuster. During installation of these bolts the event occurred.
During installation of these bolts the event occurred.
Tpough the technician does not recall contacting the relay, this is what has been determined to have occurred to cause this event.
Tpough the technician does not recall contacting the relay, this is what has been determined to have occurred to cause this event. Work within this cabinet is not normally conducted with the Unit in .operation.
Work within this cabinet is not normally conducted with the Unit in
The circumstances requiring replacement of the voltage adjuster warranted the risk. As explained above, the potential challenge to the plant and safety systems were minimized.
    .operation. The circumstances requiring replacement of the voltage adjuster warranted the risk. As explained above, the potential challenge to the plant and safety systems were minimized.
* ANALYSIS OF OCCURRENCE:
* ANALYSIS OF OCCURRENCE:
The "turbine trip" :function, when operating above P-9, part of the Reactor Protection System. It will cause a direct reactor trip when operating aeove P-9 thereby providing turbine protection and reducing -the severity of the ensuing transient.
The "turbine trip" :function, when operating above P-9, part of the Reactor Protection System. It will cause a direct reactor trip when operating aeove P-9 thereby providing turbine protection and reducing
No credit is taken in the
    - the severity of the ensuing transient.       No credit is taken in the
* accident analyses for this trip function.
* accident analyses for this trip function.
This event did not affect the health or safety of the public*..
This event did not affect the health or safety of the public*.. Since a turbine trip is an RPS function, this event is reportable to the NRC in accordance with Code of Federal Regulations 10CFR 50.73(a) (2) (iv).
Since a turbine trip is an RPS function, this event is reportable to the NRC in accordance with Code of Federal Regulations lOCFR 50.73(a) (2) (iv). CORRECTIVE ACTION: No corrective actions are warranted based on the circumstances surrounding this event; however, .this event was discussed with those individuals involved. MJP:pc SORC Mtg. 92-101 Cbeneral Manager -. . Salem Operations}}
CORRECTIVE ACTION:
No corrective actions are warranted based on the circumstances surrounding this event; however, .this event was discussed with those individuals involved.                         ~
                                                *ih1Jtlfc~
Cbeneral Manager -
                                                  .Salem Operations MJP:pc SORC Mtg. 92-101}}

Latest revision as of 10:40, 23 February 2020

LER 92-020-00:on 920817,generator-turbine Trip Occurred Due to Generator Differential & Loss of Field During Reinstallation of Voltage Adjuster.Caused by Design Deficiency.No Corrective Actions warranted.W/920910 Ltr
ML18096A980
Person / Time
Site: Salem PSEG icon.png
Issue date: 09/10/1992
From: Pollack M, Vondra C
Public Service Enterprise Group
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-020, LER-92-20, NUDOCS 9209210050
Download: ML18096A980 (4)
v • d • e


Text

e PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station September 10, *1992 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 LICENSEE EVENT REPORT 92-020-00 This Licensee Event Report is being submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73(a) (2) (iv). This report is required to be issued within thirty (30) days of event discovery.

C. A Vondra Gen~ral Manager -

Salem Operations MJP:pc Distribution 180054

/r;JJ I 9209210050 920910

/)v I PDR ADOCK 05000272 95*2189 (10M) 12-89

. ~ . PDR

NRC FOFI~~ 366 U.S. NUCLEAR REGULATORY COMMISSION (6-89) APPROVED OMB NO. 3150-0104 EXPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS

  • INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD LICENSEE EVENT REPORT (LER) . COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MANAGEMENT BRANCH (P*530l. U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555. AND TO THE PAPERWORK REDUCTION PROJECT (3150-01041. OFFICE OF MANAGEMENT AND BUDGET. WASHINGTON. DC 20503.

FACILITY NAME (11 DOCKET NUMBER (2_1 .. . I PAGE 13!

Salem denerating Station - Unit 1 O I 5 I O I O I O I? I ..., I ., 1 OF n h TITLE 141 Reactor Protection System signal actuation; Turbine Trip due to design.

EVENT DATE (5) LEA NUMBER 161 REPORT DATE (71 OTHER FACILITIES INVOLVED 1er MONTH DAY  ::::::::::;SEQUENTIAL 1::::::::: REVISION DAY YEAR FACILITY NAMES DOCKET NUMBERISI YEAR YEAR *:*:*:*:*:* NUMBER 1::::::::: NUMBER MONTH 01s1010101 I I THIS REPORT IS SUBMITTED PURSUANT TO TH_E RhQUIREMENTS OF 10 CFR §:(Chock one or more of th .. fa/lawing) (111 OPERATING MODE (9) 1 20.402(b) 20.405(cl

- l...X 50.73l*H2llivi 73.71lbl POWER LEVEL I Q ,__

20.4051*111 Hil ,__ *50.36(c)(1)

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-- 73.71 (cl 1101 I 21 l 20.4051*111 Hill

-- 50.36(cll21 50.73(*)(2) (viii OTHER (Specify in Abstract below arid in Text, NRC Fo_rm 20.405(o)(1 lliiil 20.405loll1 Hivl 20.4051*111 lM 50.73(o)(2)(i) 50.73!oll2Hiil 50.73(ol(2lliiil

-- 50.73(ol(2l(viiil(A) 50,73(o)(2llviiil(BI 50,73(ol(2llxl 366AI. ,

LICENSEE CONTACT FOR THIS LEA (12)

NAME TELEPHONE NUMBER AREA CODE M.J. Pollack - LER Coordinator 61 O.19 3 I 3 19 I - 12 I O I 2 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 MANUFAC* REPORTABLE *:*: :*.* *:*: :*.**.*. MANUFAC*

CAUSE SYSTEM COMPONENT TUR ER TO NPRDS  :::;::::: *:* .*.* *.*. .*.: *.*..*.* CAUSE SYSTEM COMPONENT TUR ER I I I I I I I )) *:*-:*: :-:**:* .;.:;.: *:**:-:;.:

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I I I I I I I  :::;:::: I I I I I. I I *.*..*.*.*.**.*;*.*;:*:*:-:.;.:;*;*-:.;.:.;

SUPPLEMENTAL REPORT EXPECTED (141 MONTH DAY YEAR EXPECTED

_, YES (If. yes. complete EXPECTED SUBMISSION DATE!

ABSTRACT fL,(mir to 1400 spaces, i.e., approximately fifteBn single-space type_writtan lines) (16) h NO SUBMISSION DATE 1151 I I *I On 8/17/92, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per I design. At the time, the Unit was maintaining 21% reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49%. Prior to the trip the automatic voltage regulator had been declared inoperable. The generator-turbine trip occurred during the reinstallation of the voltage adjuster. Station management had decided to delay putting the Unit on line to minimize a plant tiansient, if a problem developed with the voltage regulator repair. The root cause of this event is "Other"~ Investigation of this event revealed that Relay 5-86 (MG-6) initiated the generator-turbine trip. Energization of the relay causes "loss of field" which results in a generator-turbine trip. It is not considered possible for this relay to trip without excitation of the generator. Physical contact had to have been made during the voltage regulator adjuster installation. The 5~86 relay is neither covered nor encased to prevent inadv~rtent contact. It is also located very close to the voltage adjuster which was being replaced. The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line

  • during this evolution. No corrective actions are warranted based on* the circµmstances surrounding this event; however, this event was discussed with those individuals involved.

NRC Form 366 (6-891

--,1 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION.

Salem* Generating station DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272* 92-020-00 . 2 of 3 PLANT AND SYSTEM* IDENTIFICATION:

Westinghouse - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in the text as {xx}

IDENTIFICATION OF OCCURRENCE:

React6r Protection System sign~l actuation; Turbine Trip due to design Event Date: 8/17/92 Report Date: 9/10/92 This. report was initiated by Incident Report No. 92-:-521.

CONDITIONS PRIOR TO OCCURRENCE:

Mode 1 Reactor Power 21% - Unit Load O MWe DESCRIPTION OF.OCCURRENCE:

On August 17, 1992, at 1737 hours0.0201 days <br />0.483 hours <br />0.00287 weeks <br />6.609285e-4 months <br />, a generator-turbine trip occurred due to "Generator Differential and Loss of Field". The turbine stop valves closed per design. At the time, the Unit was maintaining 21%

reactor power with the turbine latched. A reactor trip directly occurs on a turbine trip only if reactor power is above 49% (i.e.,

permissive P-9).

~rior to the turbine trip the automatic voltage regulator had been

  • declared inoperable. Troubleshooting revealed that the voltage adjuster was mechanically binding. The generator-turbine trip occurred during the reinstallation of the voltage adjuster. station management had decided to delay putting the Unit on line to minimize a plant transient, if a problem developed with the voltage regulator repair.

A generator-turbine trip is a Reactor Prqtection System {RPS) {JC}

function. On August 17, 1992, at 1808 hours0.0209 days <br />0.502 hours <br />0.00299 weeks <br />6.87944e-4 months <br />, this event was reported to the Nuclear Regulatory Commission (NRC) in accordance with Code of Federal Regulations 10CFR 50.72{b) (2) (ii).

APPARENT CAUSE OF OCCURRENCE:

The root cause of this event is "Other" (per NUREG 1022, "Licensee

  • Event Report Program") .

Investigation of this event, by System Engineering, revealed that Relay 5-86 (MG-G) initiated the generator-turbine trip. This relay is triggered by field forcing or over-excitation. Energization of

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272 92-020.,...00 3 of 3

.APPARENT CAUSE OF OCCURRENCE: (cont'd) the.relay causes "loss of field" which results in a ge~erator-turbine trip. It is not considered possible for this relay to trip without excitation of the generator. Physical contact had to have been made during the voltage regulator adjuster installation.

The 5 ... a6 relay (as well as the other relays in the Voltage Regulator Cubicle) is -neither *covered nor encased to prevent inadvertent.

contact. It is.also located very close to the voltage adjuster which was being replaced. The tight conditions and possible consequences were recognized by station management, so the unit was maintained off-line during this evolution.

Installation of the voltage adjuster includes two bolts located behind

-the adjuster. During installation of these bolts the event occurred.

Tpough the technician does not recall contacting the relay, this is what has been determined to have occurred to cause this event.

Work within this cabinet is not normally conducted with the Unit in

.operation. The circumstances requiring replacement of the voltage adjuster warranted the risk. As explained above, the potential challenge to the plant and safety systems were minimized.

  • ANALYSIS OF OCCURRENCE:

The "turbine trip" :function, when operating above P-9, part of the Reactor Protection System. It will cause a direct reactor trip when operating aeove P-9 thereby providing turbine protection and reducing

- the severity of the ensuing transient. No credit is taken in the

  • accident analyses for this trip function.

This event did not affect the health or safety of the public*.. Since a turbine trip is an RPS function, this event is reportable to the NRC in accordance with Code of Federal Regulations 10CFR 50.73(a) (2) (iv).

CORRECTIVE ACTION:

No corrective actions are warranted based on the circumstances surrounding this event; however, .this event was discussed with those individuals involved. ~

  • ih1Jtlfc~

Cbeneral Manager -

.Salem Operations MJP:pc SORC Mtg.92-101

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