ML18096A862: Difference between revisions

From kanterella
Jump to navigation Jump to search
(Created page by program invented by StriderTol)
(Created page by program invented by StriderTol)
 
(2 intermediate revisions by the same user not shown)
Line 16: Line 16:


=Text=
=Text=
{{#Wiki_filter:'*
{{#Wiki_filter:..
Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station u. s. Nuclear Regulatory Commission Document Desk Washington, DC 20555  
C~ PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station July 23, 1992
: u.           s. Nuclear Regulatory Commission Document ~ontrol Desk Washington, DC                                       20555


==Dear sir:==
==Dear sir:==
SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 July 23, 1992 SUPPLEMENTAL LICENSEE EVENT REPORT.92-011-01 This Licensee Event Report supplement .is being _submitted pursuant to the requirements of the Code of Federal Regulations lOCFR 50.73. It addresses a second event which has the same root cause* as the first event. Both events are reportable per Code of Federal Regulations lOCFR 50.73(a) (2) (iv). rhis report is required to be issued within thirty (30) days.of event discovery.
 
MJP:pc Distriblition Sincerely yours, /. ' 1, c. A Vondra General Manager -Salem Operations  
SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 SUPPLEMENTAL LICENSEE EVENT REPORT.92-011-01 This Licensee Event Report supplement .is being _submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73. It addresses a second event which has the same root cause*
.. "i' hr.* E '"l ''''(/\.I f:":' '°'Cl i'\ i E''. :
as the first event. Both events are reportable per Code of Federal Regulations 10CFR 50.73(a) (2) (iv). rhis report is required to be issued within thirty (30) days.of event discovery.
* I,,,,* ** I '-' i 0) 1 \_* :--*I .* 9208030331 920723 PDR ADOCK 05000272 .
Sincerely yours,
I ./jv*. ! 95-2189 (10M) 12-9 FORM 366 (6-89) .. -*-.*. U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3150-0104 E_XPIRES:
                                                                      /.
4/30/92 LICENSEE EVENT REPORT (LER) ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD
                                                                    ~ ' 1,
* COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MA.NAGEMENT B.RANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MA.NAG EM ENT AND BUDGET, WASHINGTON, DC 20503. FACILITY NAME (1) Salem Generating Station -Unit 1 I DOCKET NUMBER (2) . I PAGE 131 o 15 Io Io IO 12 I 712 1 loF O 14 TITLE 141 ESF Signal Actuati"ons:
: c. A Vondra General Manager -
Control Rm Vent. Switch To Erner. Mode Due To RMS Channel .Spike EVENT DATE (5) LER NUMBER (61
Salem Operations MJP:pc Distriblition
* REPORT DATE (71 OTHER FACILITIES INVOLVED lBI MONTH *oAY YEAR YEAR :)]:  
                                                                                          . /{;ff~            I "i': *hr.*
})
I,,,,* E'"l ''''(/\.I
MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI a 16 211 9 2 9 I 2 -a 1111 -a 11 011 213 91 2 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE OF 10 CFR §: (Check ons or more gf the following}
                  ** I 9208030331 920723
111) MODE (9) 5 20.402(b) 20.405(c)
                        '-' i 0 ) 1f:":' '°'Cl i'\ i E''.
X 60.73(1)(2)(iv)  
                                        \_* :--*I   .*
,___ ,_. 60.38(c)(1) 60.73(1J!2i1v1
                                                                                          ./jv*.                 !
--'--'--73.71(b) 73.71(c) POWER I o 10 1 o ,__ lf 11= 20.406(0)(1  
95-2189 (10M) 12- 9 PDR ADOCK 05000272
)(i) :Zo.40s111i11m1 20.40t5(o)(1
 
)(ill) 20.405(0)(1  
NR~ FORM 366                                                                     U.S. NUCLEAR REGULATORY COMMISSION (6-89)                                                                                                                                            APPROVED OMB NO. 3150-0104 E_XPIRES: 4/30/92 ESTIMATED BURDEN PER RESPONSE TO COMPLY WTH THIS INFORMATION COLLECTION REQUEST: 50.0 HRS. FORWARD
)(Iv) 20.405(o)(1)(v)
* LICENSEE EVENT REPORT (LER)                                                              COMMENTS REGARDING BURDEN ESTIMATE TO THE RECORDS AND REPORTS MA.NAGEMENT B.RANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MA.NAG EM ENT AND BUDGET, WASHINGTON, DC 20503.
'--50.35(cl!21 1--50.73lol!2Hil 60.73(11!2Hviil 60.73(1) (2) (viii) (A) '--OTHER (Specify in Absrr*ct b*low *nd in Text, NRC Form 366AF --50.73(o)(2)(ii) 60.73(1)(2)(vili)(BI  
I FACILITY NAME (1)                                                                                                                           DOCKET NUMBER (2)         .       I     PAGE 131 Salem Generating Station - Unit 1                                                                                                          o 15 Io Io IO 12 I 712               1 loF   O 14 TITLE 141 ESF Signal Actuati"ons: Control Rm Vent. Switch To Erner. Mode Due To RMS Channel .Spike EVENT DATE (5)                       LER NUMBER (61
,___ ,....._ 50.73(1)(2)(iii) 60.73(1)(21!*1 LICE.NSEE CONTACT FOR THIS LER (12) NAME TELEPHONE NUMBER AREA CODE M.* J. Pollack -LER Coordinator 6 IO 19 3 13 I 91-12 I O 12 12 CAUSE SYSTEM COMPONENT* . I I I I I COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13) TURER I I I I I. I I I I I I I *I I I I I I I I SUPPLEMENTAL REPORT EXPECTED 1141 MONTH DAY YEAR n YES !If yss. complsts EXPECTED SUBMISSION DA TEI . EXPECTED SUBMISSION DATE.(151 I I ABSTRACT (Limit to 1400 spaces, i.fl .. approximtJtely fifteen typewritten lines} 1161 This LER supplement addi::esses two Engineered Safety Feature (ESF) signal actuations for Control' Room Ventilation automatically switching from normal to accident *mode of operation for both Salem Units 1 and 2 (by design). A channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) channel, lRlB precipitated both events. The , first event occurred on 5/23/92. The cause was attributed to the "C" GM tube detector not being fully inserted into its 3 pin socket connection.
* REPORT DATE (71                           OTHER FACILITIES INVOLVED lBI MONTH     *oAY       YEAR     YEAR   :)]: SE~~~~~~AL    })   ~~~~~~      MONTH       DAY       YEAR           FACILITY NAMES                       DOCKET NUMBERISI a 16       211 9           2 9   I2 -       a     1111 -         a 11       011         213 91 2 OPERATING                 THIS REPORT IS SUBMITTED PURSUANT TO THE R~QUIREMENTS OF 10 CFR               §: (Check ons or more gf the following} 111)
After reinsertion of the detector, the spiking could not be repeated (at that time). Therefore, it was concluded to be the cause of tpe event. The GM tubes hang from the top of the duct. They are inserted in strain relief connectors in which the rubber grommet had embrittled (due to age) allowing the detector pins to slip. The grommet was replaced.
MODE (9)           5 t----~--....&..._....--1 20.402(b)
On 6/27/92, the second event occurred.
Io                                                                                                X                                                73.71(b)
The root cause of both events is attributed to equipment failure. Investigation of the second event is continuing.
                                                                          ,___    20.405(c)
The charinel spike has not recurred since removing the channel from service (6/27/92).
                                                                                                              ,_.      60.73(1)(2)(iv)
Investigation has identified:
POWER L~1~~L          10 1 o ,__
: 1) the detector prongs exhibited corrosion and 2) soldered connections did not -fully comply with vendor drawings which require "Coat High Voltage connections with Corona Dope". The preventive maintenance program for LFE MD-12C detectors will be revised. RMS channels which use LFE MD-12C detectors will be inspected and aged parts will be replaced as required.
20.406(0)(1 )(i)
Corona Dope will be purchased and placed on folio. Upon receipt it will be used to correct solder connection deficiencies as applicable.
:Zo.40s111i11m1                     -'--
NRC Form 366 (6-89) I LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station Unit 1 DOCKET NUMBER 5000272 PLANT AND SYSTEM IDENTIFICATION:
60.38(c)(1) 50.35(cl!21               -         60.73(1J!2i1v1 60.73(11!2Hviil 73.71(c)
Westinghouse*  
OTHER (Specify in Absrr*ct b*low *nd in Text, NRC Form 1--
-Pressurized Water Reactor LER NUMBER 92-011-01 PAGE 2 of 4 Energy Industry Identification System (EIIS) codes are identified in the.text {xx} IDENTIFICATION OF OCCURRENCE:
lflllt~*lf11=
Engineered Safety Feature Signal Actuations:
20.40t5(o)(1 )(ill)                        50.73lol!2Hil                        60.73(1) (2) (viii) (A)                    366AF 20.405(0)(1 )(Iv)                          50.73(o)(2)(ii)                       60.73(1)(2)(vili)(BI 20.405(o)(1)(v)                            50.73(1)(2)(iii)                     60.73(1)(21!*1 LICE.NSEE CONTACT FOR THIS LER (12)
Control Room Ventilation switch to emergency mode due to lRlB: channel spike Discovery Date: 5/23/92 and 6/27/92 Report Date: 7/23/92 Thi$ report was initiated by Incident Report Nos. 92-335 and 92:-414. CONDITIONS PRIOR TO OCCURRENCE:
NAME                                                                                                                                                         TELEPHONE NUMBER AREA CODE M.* J. Pollack - LER Coordinator                                                                                                                 6 IO 19     3 13 I 91- 12 I O 12 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)
5/23/92: 6/27/92: Reactor defueled -10th Refueling Outage in prog.ress Mode 5 (Cold Shutdown)
MANUFAC-CAUSE    SYSTEM        COMPONENT*
TURER
              .I                                                                                                                                  I  I  I I     I   I                                                   I           I   I      I I         I   I   I         I     I. I                                                   I           I *I       I         I   I   I SUPPLEMENTAL REPORT EXPECTED 1141                                                                                   MONTH     DAY     YEAR EXPECTED n
SUBMISSION DATE.(151 YES !If yss. complsts EXPECTED SUBMISSION DA TEI .                                                                                                                                     I I         I ABSTRACT (Limit to 1400 spaces, i.fl.. approximtJtely fifteen sing~e-spact1 typewritten lines} 1161 This LER supplement addi::esses two Engineered Safety Feature (ESF) signal actuations for Control' Room Ventilation automatically switching from normal to accident *mode of operation for both Salem Units 1 and 2 (by design). A channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) channel, lRlB precipitated both events. The ,
first event occurred on 5/23/92. The cause was attributed to the "C" GM tube detector not being fully inserted into its 3 pin socket connection.
After reinsertion of the detector, the spiking could not be repeated (at that time). Therefore, it was concluded to be the cause of tpe event.
The GM tubes hang from the top of the duct. They are inserted in strain relief connectors in which the rubber grommet had embrittled (due to age) allowing the detector pins to slip. The grommet was replaced. On 6/27/92, the second event occurred. The root cause of both events is attributed to equipment failure.                                                           Investigation of the second event is continuing. The charinel spike has not recurred since removing the channel from service (6/27/92). Investigation has identified: 1) the detector prongs exhibited corrosion and 2) soldered connections did not
  -fully comply with vendor drawings which require "Coat High Voltage connections with Corona Dope". The preventive maintenance program for LFE MD-12C detectors will be revised. RMS channels which use LFE MD-12C detectors will be inspected and aged parts will be replaced as required.
Corona Dope will be purchased and placed on folio.                                                                                     Upon receipt it will be used to correct solder connection deficiencies as applicable.
NRC Form 366 (6-89)
 
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station       DOCKET NUMBER    LER NUMBER        PAGE Unit 1                           5000272         92-011-01        2 of 4 PLANT AND SYSTEM IDENTIFICATION:
Westinghouse* - Pressurized Water Reactor Energy Industry Identification System (EIIS) codes are identified in the.text a~ {xx}
IDENTIFICATION OF OCCURRENCE:
Engineered Safety Feature Signal Actuations: Control Room Ventilation switch to emergency mode due to lRlB: channel spike Discovery Date:   5/23/92 and 6/27/92 Report Date:   7/23/92 Thi$ report was initiated by Incident Report Nos. 92-335 and 92:-414.
CONDITIONS PRIOR TO OCCURRENCE:
5/23/92:   Reactor defueled - 10th Refueling Outage in prog.ress 6/27/92:  Mode 5 (Cold Shutdown)
DESCRIPTION OF OCCURRENCE:
DESCRIPTION OF OCCURRENCE:
This LER supplement addresses two Engineered Safety Feature (ESF) signal actuations for Controi Room Ventilation automatically switching from normal to accident mode of*operation (100% recirculation) for both Salem Unit 1 and Salem Unit 2 (by design). Both events occurred as a result of a channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) {IL} channel, lRlB LER 272/92-0*11-00 was issued addressing the first event, which occurred' on May 23, 1992, at 1614 hours. At 1732 hours, that day, the Nuclear Regulatory Commission (NRC) was notified in accordanc.e with the tode of Federal Regulations lOCFR 50.72{b) (2) (ii). The cause of the.first event was attributed to equipment failure. The lRlB RMS monitor consists of four parallel Geiger-Mueller (GM) tube detectors (LFE Model MD-12C). Investigation identified that the "C" GM tube detector was not fully inserted into its three (3) pin socket connection.
This LER supplement addresses two Engineered Safety Feature (ESF) signal actuations for Controi Room Ventilation automatically switching from normal to accident mode of*operation (100%
lRlB RMS channel spiking was reproduced by vibration.of the*ventilation duct in.which the detector is located. The spiking could not be repeated (at that time) after reinsertion of the detector.
recirculation) for both Salem Unit 1 and Salem Unit 2 (by design).
Therefore, it was concluded to be the cause of the event. The GM tubes hang from the top of the duct. *They are inserted in Crouse Hinds strain re.lief connectors.
Both events occurred as a result of a channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) {IL} channel, lRlB LER 272/92-0*11-00 was issued addressing the first event, which occurred' on May 23, 1992, at 1614 hours. At 1732 hours, that day, the Nuclear Regulatory Commission (NRC) was notified in accordanc.e with the tode of Federal Regulations 10CFR 50.72{b) (2) (ii).
Investigation indicated that the rubber grommet inside the connector had embrittled*due to age. over time, duct vibration had caused the detector pins to slip out of LICENSEE EVENT REPORT* (LER) TEXT CONTINUATION  
The cause of the.first event was attributed to equipment failure.
... Salem Generating Station DOCKET NUMBER 5000272 LER NUMBER 92-011-01 PAGE 3 of 4 Unit 1 . DESCRIPTION OF OCCURRENCE':
The lRlB RMS monitor consists of four parallel Geiger-Mueller (GM) tube detectors (LFE Model MD-12C). Investigation identified that the "C" GM tube detector was not fully inserted into its three (3) pin socket connection. lRlB RMS channel spiking was reproduced by vibration.of the*ventilation duct in.which the detector is located.
C cont 1 d). their*sockets.
The spiking could not be repeated (at that time) after reinsertion of the detector. Therefore, it was concluded to be the cause of the event.
On June 27, 1992, at 0930 hours, the second lRlB RMS channel spike event occurred.
The GM tubes hang from the top of the duct. *They are inserted in Crouse Hinds strain re.lief connectors. Investigation indicated that the rubber grommet inside the connector had embrittled*due to age.
The NRC was notified at 1156 hours, that day, in
over time, duct vibration had caused the detector pins to slip out of
* accordance with the Code of Federal Regulations lOCFR 50.72(b) (2) (ii). APPARENT CAUSE OF OCCURRENCE:
 
The root cause of both events is attributed to equipment*
LICENSEE EVENT REPORT* (LER) TEXT CONTINUATION Salem Generating Station           DOCKET NUMBER     LER NUMBER       PAGE Unit 1        .                    5000272        92-011-01       3 of 4 DESCRIPTION OF OCCURRENCE':     Ccont 1 d).
failure resulting from "Design, Manufacturing, Construction/Installation" (per NUREG 1022, "Licensee Event Report system").
their*sockets.
* As stated above, the first event was caused by partial insertion of* the "C" detector.
On June 27, 1992, at 0930 hours, the second lRlB RMS channel spike event occurred. The NRC was notified at 1156 hours, that day, in
Investigation of the second event is The channel spike has not recurred since removing the channel from service (June 27, 1992). The cables from the preamplifier to the* ratemeter were "meggered" with no abnormal or unusual results. Investigation has identified the following concerns:
* accordance with the Code of Federal Regulations 10CFR 50.72(b) (2) (ii).
: 1. the detector prongs exhibited corrosion The channel detectors are exposed to external environmental conditions which promote channel failure. 2. soldered connections did not fully.comply with vendor drawings which require "Coat High Voltage connections with Corona Dope" Channel preamp soldered connections must be covered with "corona dope". The* lRlB RMS channel manufacturer technical manual states that "circuitry inside the junction boxes must maintain a very high-impedance" and therefore the precal,ltion of covering soldered terminal points with corona dope is specified".
APPARENT CAUSE OF OCCURRENCE:
The root cause of both events is attributed to equipment* failure resulting from "Design, Manufacturing, Construction/Installation" (per NUREG 1022, "Licensee Event Report system").
* As stated above, the first event was caused by partial insertion of*
the "C" detector. Investigation of the second event is continuing~
The channel spike has not recurred since removing the channel from service (June 27, 1992). The cables from the preamplifier to the*
ratemeter were "meggered" with no abnormal or unusual results.
Investigation has identified the following concerns:
: 1. the detector prongs exhibited corrosion The channel detectors are exposed to external environmental conditions which promote channel failure.
: 2. soldered connections did not fully.comply with vendor drawings which require "Coat High Voltage connections with Corona Dope" Channel preamp soldered connections must be covered with "corona dope". The* lRlB RMS channel manufacturer technical manual states that "circuitry inside the junction boxes must maintain a very high-impedance" and therefore the precal,ltion of covering soldered terminal points with corona dope is specified".
ANALYSIS OF OCCURRENCE:
ANALYSIS OF OCCURRENCE:
The lRlB channel continuously monitors air from the HVAC intake duct into the Unit 1 Contrp_l Room. If any of the four (4) GM tubes ;reaches the alarm setpoint the monitor actuates an alarm initiating closure of the duct intake valve to prevent contaminated air from entering the control room. * * * *
The lRlB channel continuously monitors air from the HVAC intake duct into the Unit 1 Contrp_l Room. If any of the four (4) GM tubes ;reaches the alarm setpoint the monitor actuates an alarm initiating closure of the duct intake valve to prevent contaminated air from entering the control room. *               *       *                   *
* The lRlA channel (Control Room General 'Area Monitor) did not indicate *an.increase in Control Room radiation levels during these events. * .This channel has the same automatic isolation function as the lRlB bbannel.
* The lRlA channel (Control Room General 'Area Monitor) did not indicate
* These events were not the*result of high radioactivity; therefore, LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating*
      *an.increase in Control Room radiation levels during these events. *
Station Unit 1 DOCKET NUMBER 5000272 ANALYSIS OF OCCURRENCE: (cont'd) LER NUMBER 92-011-01 . PAGE 4 of 4 the health and safety of the public was not affected.
      .This channel has the same automatic isolation function as the lRlB bbannel.
However, since Control Room ventilation system switching to the accident mode of operation is an ESF actuation, these events are reportable to the in accordance with Code of Federal Regulations lOCFR .50.73 (a) (2) (iv).* CORRECTIVE ACTION: *The lRlB RMS channel "C" detecto'r connector grommet was replaced and the detector reinserted into its connector socket. * *The other lRlB RMS channel detectors.
* These events were not the*result of high radioactivity; therefore,
were verified to be correctly conne_cted;  
 
*however, they too had aged grommets in their. connectors.
j.
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating* Station         DOCKET NUMBER    LER NUMBER      . PAGE Unit 1                               5000272       92-011-01        4 of 4 ANALYSIS OF OCCURRENCE:       (cont'd) the health and safety of the public was not affected. However, since Control Room ventilation system switching to the accident mode of operation is an ESF actuation, these events are reportable to the ~RC in accordance with Code of Federal Regulations 10CFR .50.73 (a) (2) (iv).*
CORRECTIVE ACTION:
        *The lRlB RMS channel "C" detecto'r connector grommet was replaced and the detector reinserted into its connector socket.
      * *The other lRlB RMS channel detectors. were verified to be correctly conne_cted; *however, they too had aged grommets in their. connectors.
* Upon receipt of new. grommets, they too will be replaced.
* Upon receipt of new. grommets, they too will be replaced.
The preventive pr9gram for RMS channels using LFE MD-12C detectors will be revised to require periodic connector parts. replacement.
The preventive maintenan~e pr9gram for RMS channels using LFE MD-12C detectors will be revised to require periodic connector parts.
replacement.
Other RMS channels which use LFE MD-12C_detectors will be inspected and aged parts will be replaced as required.
Other RMS channels which use LFE MD-12C_detectors will be inspected and aged parts will be replaced as required.
Corona Dope will be purchased and placed on folio. Upo_n receipt it will be used to correct solder connection deficiencies as applicable.
Corona Dope will be purchased and placed on folio. Upo_n receipt it will be used to correct solder connection deficiencies as applicable.
Investigation of the second event is continuing.
Investigation of the second event is continuing.
I MJP:pc I. SORC Mtg. 92-086 j.}}
I I.
MJP:pc SORC Mtg. 92-086}}

Latest revision as of 06:30, 3 February 2020

LER 92-011-01:on 920523 & 0627,ESF Signal Actuations for Control Room Ventilation Automatically Switched from Normal to Accident Mode of Operation.Caused by Rms Channel Spike. Detector Connector Grommet replaced.W/920723 Ltr
ML18096A862
Person / Time
Site: Salem PSEG icon.png
Issue date: 07/23/1992
From: Pollack M, Vondra C
Public Service Enterprise Group
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
LER-92-011, LER-92-11, NUDOCS 9208030331
Download: ML18096A862 (5)
v • d • e


Text

..

C~ PS~G Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Salem Generating Station July 23, 1992

u. s. Nuclear Regulatory Commission Document ~ontrol Desk Washington, DC 20555

Dear sir:

SALEM GENERATING STATION LICENSE NO. DPR-70 DOCKET NO. 50-272 UNIT NO. 1 SUPPLEMENTAL LICENSEE EVENT REPORT.92-011-01 This Licensee Event Report supplement .is being _submitted pursuant to the requirements of the Code of Federal Regulations 10CFR 50.73. It addresses a second event which has the same root cause*

as the first event. Both events are reportable per Code of Federal Regulations 10CFR 50.73(a) (2) (iv). rhis report is required to be issued within thirty (30) days.of event discovery.

Sincerely yours,

/.

~ ' 1,

c. A Vondra General Manager -

Salem Operations MJP:pc Distriblition

. /{;ff~ I "i': *hr.*

I,,,,* E'"l '(/\.I

    • I 9208030331 920723

'-' i 0 ) 1f:":' '°'Cl i'\ i E.

\_* :--*I .*

./jv*.  !

95-2189 (10M) 12- 9 PDR ADOCK 05000272

NR~ FORM 366 U.S. NUCLEAR REGULATORY COMMISSION (6-89) APPROVED OMB NO. 3150-0104 E_XPIRES: 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 MA.NAGEMENT B.RANCH (P-530), U.S. NUCLEAR REGULATORY COMMISSION, WASHINGTON, DC 20555, AND TO THE PAPERWORK REDUCTION PROJECT (3150-0104), OFFICE OF MA.NAG EM ENT AND BUDGET, WASHINGTON, DC 20503.

I FACILITY NAME (1) DOCKET NUMBER (2) . I PAGE 131 Salem Generating Station - Unit 1 o 15 Io Io IO 12 I 712 1 loF O 14 TITLE 141 ESF Signal Actuati"ons: Control Rm Vent. Switch To Erner. Mode Due To RMS Channel .Spike EVENT DATE (5) LER NUMBER (61

  • REPORT DATE (71 OTHER FACILITIES INVOLVED lBI MONTH *oAY YEAR YEAR  :)]: SE~~~~~~AL }) ~~~~~~ MONTH DAY YEAR FACILITY NAMES DOCKET NUMBERISI a 16 211 9 2 9 I2 - a 1111 - a 11 011 213 91 2 OPERATING THIS REPORT IS SUBMITTED PURSUANT TO THE R~QUIREMENTS OF 10 CFR §: (Check ons or more gf the following} 111)

MODE (9) 5 t----~--....&..._....--1 20.402(b)

Io X 73.71(b)

,___ 20.405(c)

,_. 60.73(1)(2)(iv)

POWER L~1~~L 10 1 o ,__

20.406(0)(1 )(i)

Zo.40s111i11m1 -'--

60.38(c)(1) 50.35(cl!21 - 60.73(1J!2i1v1 60.73(11!2Hviil 73.71(c)

OTHER (Specify in Absrr*ct b*low *nd in Text, NRC Form 1--

lflllt~*lf11=

20.40t5(o)(1 )(ill) 50.73lol!2Hil 60.73(1) (2) (viii) (A) 366AF 20.405(0)(1 )(Iv) 50.73(o)(2)(ii) 60.73(1)(2)(vili)(BI 20.405(o)(1)(v) 50.73(1)(2)(iii) 60.73(1)(21!*1 LICE.NSEE CONTACT FOR THIS LER (12)

NAME TELEPHONE NUMBER AREA CODE M.* J. Pollack - LER Coordinator 6 IO 19 3 13 I 91- 12 I O 12 12 COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

MANUFAC-CAUSE SYSTEM COMPONENT*

TURER

.I I I I I I I I I I I I I I I I I. I I I *I I I I I SUPPLEMENTAL REPORT EXPECTED 1141 MONTH DAY YEAR EXPECTED n

SUBMISSION DATE.(151 YES !If yss. complsts EXPECTED SUBMISSION DA TEI . I I I ABSTRACT (Limit to 1400 spaces, i.fl.. approximtJtely fifteen sing~e-spact1 typewritten lines} 1161 This LER supplement addi::esses two Engineered Safety Feature (ESF) signal actuations for Control' Room Ventilation automatically switching from normal to accident *mode of operation for both Salem Units 1 and 2 (by design). A channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) channel, lRlB precipitated both events. The ,

first event occurred on 5/23/92. The cause was attributed to the "C" GM tube detector not being fully inserted into its 3 pin socket connection.

After reinsertion of the detector, the spiking could not be repeated (at that time). Therefore, it was concluded to be the cause of tpe event.

The GM tubes hang from the top of the duct. They are inserted in strain relief connectors in which the rubber grommet had embrittled (due to age) allowing the detector pins to slip. The grommet was replaced. On 6/27/92, the second event occurred. The root cause of both events is attributed to equipment failure. Investigation of the second event is continuing. The charinel spike has not recurred since removing the channel from service (6/27/92). Investigation has identified: 1) the detector prongs exhibited corrosion and 2) soldered connections did not

-fully comply with vendor drawings which require "Coat High Voltage connections with Corona Dope". The preventive maintenance program for LFE MD-12C detectors will be revised. RMS channels which use LFE MD-12C detectors will be inspected and aged parts will be replaced as required.

Corona Dope will be purchased and placed on folio. Upon receipt it will be used to correct solder connection deficiencies as applicable.

NRC Form 366 (6-89)

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 1 5000272 92-011-01 2 of 4 PLANT AND SYSTEM IDENTIFICATION:

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

IDENTIFICATION OF OCCURRENCE:

Engineered Safety Feature Signal Actuations: Control Room Ventilation switch to emergency mode due to lRlB: channel spike Discovery Date: 5/23/92 and 6/27/92 Report Date: 7/23/92 Thi$ report was initiated by Incident Report Nos.92-335 and 92:-414.

CONDITIONS PRIOR TO OCCURRENCE:

5/23/92: Reactor defueled - 10th Refueling Outage in prog.ress 6/27/92: Mode 5 (Cold Shutdown)

DESCRIPTION OF OCCURRENCE:

This LER supplement addresses two Engineered Safety Feature (ESF) signal actuations for Controi Room Ventilation automatically switching from normal to accident mode of*operation (100%

recirculation) for both Salem Unit 1 and Salem Unit 2 (by design).

Both events occurred as a result of a channel spike of the Control Room Air Intake Radiation Monitoring System (RMS) {IL} channel, lRlB LER 272/92-0*11-00 was issued addressing the first event, which occurred' on May 23, 1992, at 1614 hours0.0187 days <br />0.448 hours <br />0.00267 weeks <br />6.14127e-4 months <br />. At 1732 hours0.02 days <br />0.481 hours <br />0.00286 weeks <br />6.59026e-4 months <br />, that day, the Nuclear Regulatory Commission (NRC) was notified in accordanc.e with the tode of Federal Regulations 10CFR 50.72{b) (2) (ii).

The cause of the.first event was attributed to equipment failure.

The lRlB RMS monitor consists of four parallel Geiger-Mueller (GM) tube detectors (LFE Model MD-12C). Investigation identified that the "C" GM tube detector was not fully inserted into its three (3) pin socket connection. lRlB RMS channel spiking was reproduced by vibration.of the*ventilation duct in.which the detector is located.

The spiking could not be repeated (at that time) after reinsertion of the detector. Therefore, it was concluded to be the cause of the event.

The GM tubes hang from the top of the duct. *They are inserted in Crouse Hinds strain re.lief connectors. Investigation indicated that the rubber grommet inside the connector had embrittled*due to age.

over time, duct vibration had caused the detector pins to slip out of

LICENSEE EVENT REPORT* (LER) TEXT CONTINUATION Salem Generating Station DOCKET NUMBER LER NUMBER PAGE Unit 1 . 5000272 92-011-01 3 of 4 DESCRIPTION OF OCCURRENCE': Ccont 1 d).

their*sockets.

On June 27, 1992, at 0930 hours0.0108 days <br />0.258 hours <br />0.00154 weeks <br />3.53865e-4 months <br />, the second lRlB RMS channel spike event occurred. The NRC was notified at 1156 hours0.0134 days <br />0.321 hours <br />0.00191 weeks <br />4.39858e-4 months <br />, that day, in

APPARENT CAUSE OF OCCURRENCE:

The root cause of both events is attributed to equipment* failure resulting from "Design, Manufacturing, Construction/Installation" (per NUREG 1022, "Licensee Event Report system").

  • As stated above, the first event was caused by partial insertion of*

the "C" detector. Investigation of the second event is continuing~

The channel spike has not recurred since removing the channel from service (June 27, 1992). The cables from the preamplifier to the*

ratemeter were "meggered" with no abnormal or unusual results.

Investigation has identified the following concerns:

1. the detector prongs exhibited corrosion The channel detectors are exposed to external environmental conditions which promote channel failure.
2. soldered connections did not fully.comply with vendor drawings which require "Coat High Voltage connections with Corona Dope" Channel preamp soldered connections must be covered with "corona dope". The* lRlB RMS channel manufacturer technical manual states that "circuitry inside the junction boxes must maintain a very high-impedance" and therefore the precal,ltion of covering soldered terminal points with corona dope is specified".

ANALYSIS OF OCCURRENCE:

The lRlB channel continuously monitors air from the HVAC intake duct into the Unit 1 Contrp_l Room. If any of the four (4) GM tubes ;reaches the alarm setpoint the monitor actuates an alarm initiating closure of the duct intake valve to prevent contaminated air from entering the control room. * * * *

  • The lRlA channel (Control Room General 'Area Monitor) did not indicate
  • an.increase in Control Room radiation levels during these events. *

.This channel has the same automatic isolation function as the lRlB bbannel.

  • These events were not the*result of high radioactivity; therefore,

j.

LICENSEE EVENT REPORT (LER) TEXT CONTINUATION Salem Generating* Station DOCKET NUMBER LER NUMBER . PAGE Unit 1 5000272 92-011-01 4 of 4 ANALYSIS OF OCCURRENCE: (cont'd) the health and safety of the public was not affected. However, since Control Room ventilation system switching to the accident mode of operation is an ESF actuation, these events are reportable to the ~RC in accordance with Code of Federal Regulations 10CFR .50.73 (a) (2) (iv).*

CORRECTIVE ACTION:

  • The lRlB RMS channel "C" detecto'r connector grommet was replaced and the detector reinserted into its connector socket.
  • *The other lRlB RMS channel detectors. were verified to be correctly conne_cted; *however, they too had aged grommets in their. connectors.
  • Upon receipt of new. grommets, they too will be replaced.

The preventive maintenan~e pr9gram for RMS channels using LFE MD-12C detectors will be revised to require periodic connector parts.

replacement.

Other RMS channels which use LFE MD-12C_detectors will be inspected and aged parts will be replaced as required.

Corona Dope will be purchased and placed on folio. Upo_n receipt it will be used to correct solder connection deficiencies as applicable.

Investigation of the second event is continuing.

I I.

MJP:pc SORC Mtg.92-086

Retrieved from "https://kanterella.com/w/index.php?title=ML18096A862&oldid=2409144"