ML20059M710
| ML20059M710 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 08/20/1993 |
| From: | Rueger G PACIFIC GAS & ELECTRIC CO. |
| To: | |
| References | |
| OLA-2-I-MFP-F5, NUDOCS 9311190259 | |
| Download: ML20059M710 (8) | |
Text
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isras Pacific Gas and Electric Company 77 Beale Street
[n,.,i um Gregory M.Rueger San Francisco, CA 94106 9mc Senior Vice President and 415/973-4684 General Manager tJuclear Power Generation
'93 Ti 28 P6 :26 November 25, 1992 E
PG&E Letter No. DCL-92-259 p
p f-l U.S. Nuclear Regulatory Connission g"
l ATTN:
Document Control Desk Il hg g
$'f20/q3 l
Washington, D.C.
20555 gt Re:
Docket No. 50-323, OL-DPR-82 i
l Diablo Canyon Unit 2 Licensee Event Report 2-92-006 Technical Specifications 3.3.3.8 and 3.7.10 Not Met When Fire Watches Were Not Established Within One Hour due to Personnel Errcr l
Gentlemen:
l i
Pursuant to 10 CFR 50.73(a)(2)(1)(B), PG&E is submitting the enclosed l
Licensee Event Report concerning a violation of Technical Specifications 3.3.3.8 and 3.7.10 due to missed fire watches caused by personnel error.
These events have in no way affected the health and safety of the public.
l l
Sincerely,
/b/4" mW Greoory M. Rueger cc:
nn P. Hodgdon l
John B. Martin Mary H. Miller NUCLEAR REGutAToRY 00W13stoM i R. Peterson mFO-96'- O& or,wmWFF 8
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LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199775 FActury swet (3) ooccti HUMBER (2) tfA Nt#49th I6)
PAGE (M ma seas DIABLO CANYON UNIT 2 0l5l0l0l0l3l2l3 92
- 0l0l6 0l0 3 l'l9 itst (17)
C.
Event
Description:
On September 6, 1992, the detection zone B-8 fire detectors repeatedly alarmed and the zone was declared inoperable.
The correct compensatory measures were established until a functional test was completed and the zone was declared operable on September 22, 1992.
On Sptember 25, 1992, the detection zone B-8 fire detectors repeatedly alarmed and the zone was declared inoperable.
Again, the correct I
compensatory measures were initiated until the detector was functionally tested and the detection zone B-8 alarm was reset.
On October 19, 1992, the fire alarm for detection zone B-8 experienced the same problems that were noted on September 25, 1992. The Fire Watch Supervisor was again notified and the correct compensatory measures were implemented.
On October 24, 1992, the faulty detection zone B-8 detector was replaced.
It was noted that numerous shiny paper labels glued to the charcoal filters were loose and flapping in the wind.
These loose labels were removed to prevent possible activation of the flame detectors.
On October 30, 1992, at 1311 PST, a fire detection alarm was received in the control room (NA) for fire detection zone B-8.
The Unit 2 Senior Control Operator (SCO) attempted to reset the alarm at the appropriate control panel, but the alarm immediately returned following the reset attempt. An operator was dispatched to the area, but no fire was identified.
The SCO noted that sever:'. plant problem report stickers were in place on the fire panel (IC)(CBD) with the alarming fire detection zone.
The 500 reviewed the status of the plant problem reports and concluded that the problem was an existing situation with a previously established compensatory measure.
The SCO then ceased any further actions or investigations on the alarming detector.
On October 30, 1992, at 1411 PST, LCO action statement a. of TS 3.3.3.8 was exceeded when a compensatory measure was not established within one hour. At 1439 PST, the Shift Supervisor (SS) questioned the SCO about the alarm and noted that no compensatory measure was in effect.
The alarm was immediately reset. As a conservative action, the SCO declared the zone inoperable and a compensatory measure was initiated.
On November 14, 1992, at 1253 PST, the main annunciator (IB)(ANN) " Fire System Trouble" activated. An operator proceeded to the fire panel l
located behind the main control boards (NA)(HCBD) in the front of the control room and identified that zone B-2 was in alarm.
He immediately l
reset the alarm at the back panel while the main annunciator and the Honeywell system (IC)(CPO) were still locked in alarm. At 1254 PST, l
zone B-2 came back into alarm. At 1301 PST, the operator reset the 1078s /85K
i LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199775
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DIABLO CANYON UNIT 2 0l5l0l0l0l3l2l3 92 0l0l6 0l0 4 l'l9 Tuf (17)
Honeywell panel and the main annunciator with zone B-2 unknowingly back in alarm.
Since the fire panel is out of sight of control room personnel during routine operations and the main annunciator was clear, 1
the operator believed that detection zone B-2 was operable and no j
further actions were taken.
at 1354 PST, LCO action statement a. of TS 3.7.10 was exceeded when a continuous fire watch for an impaired fire barrier (3K2-3K3-86-19) between the 2-2 and 2-3 CCW pump rooms was not established within one hour.
Roving fire watch patrols had been provided for detection zone B-2 prior to the detector problem.
On November 16, 1992, at 0310 PST, a fire watch noted that detection zone B-2 was in alarm with no compensatory measure in place.
At 0315 PST, the Shift Foreman (SFM) reset the alarm and the zone was operable again.
It was determined that a fire watch patrol was in place, but no continuous fire watch was provided for the impaired fire barrier.
D.
Inogerable Structures, Components, or Systems that Contributed to the Cvent:
Recurring problemg with spurious alarme in--detection zones B-2 and B-8 t'aused the zones to be repeatedly placed in and out of an operable status.
E.
Dates and Approximate Times for Major Occurrences:
i 1.
September 6, 1992:
Spurious fire alarms in detection zone B-8.
2.
September 25, 1992:
Spurious fire alarms in detection i
zone B-8.
3.
October 19, 1992:
Detection zone B-8 alarmed.
4.
October 24, 1992:
I&C personnel replaced a detector in zone B-8.
5.
October 30, 1992, at 1311 PST:
Detection zone B-8 alarmed.
6.
October 30, 1992, at 1411 PST:
Event I date. The 1-hour LCO for TS 3.3.3.8 was exceeded.
7.
October 30, 1992, at 1439 PST:
Discovery date for Event 1.
The SS and SCO identified that no compensatory measure was in place.
8.
November 14, 1992, at 1253 PST: Detection zone B-2 alarmed.
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l LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199775 FACILlif NAMC (1)
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November 14, 1992, at 1254 PST: Zone B-2 alarm returned while the main annunciator and Honeywell l
alarm panel were still locked in.
- 10. November 14, 1992, at 1354 PST:
Event 2 date.
The 1-hour LCO for TS 3.7.10 was exceeded.
l i
- 11. November 16, 1992, at 0310 PST: Discovery date for Event 2.
A fire watch identified that zone 1
B 2 was in alarm without' the correct compensatory measure in place.
F.
Other Systems or Secondary Functions Affected:
None.
G.
Method of Discovery:
Event 1.
The TS violation was identified when the SS questioned the SCO about the alarm and noted that no cornpensatory measure was in place.
j Event 2.
The TS violation was identified when a fire watch noted that detection zone B-2 was in alarm without a continuous fire watch in place for the fire barrier impairment.
H.
Operators Actions:
Event 1.
The Unit 2 SFM immediately notified the Fire Watch Sr~ visor of the problem and a 1-hour-fire watch patrol was established.
Event 2.
The Unit 2 SFM immediately reset the alarm panel.
I.
Safety System Responses:
None.
'II.
Cause of the Event A.
Immediate Cause:
Event 1.
The SCO did not verify that a compensatory measure was in place when he concluded that the detection zone was inoperable.
Event 2.
The operator did not verify that detection zone B-2 was operable after resetting the main annunciator and the Honeywell panel.
B.
Root Cause:
Event 1.
The root cause was personnel error due to inadequate knowledge on the plant problem report processing program by the SCO who responded
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7 LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199775 DOCKET NUMBER (2)
LER enMBER IO PAGE O)
FACILITY fpME (1) ma asauun as DIABLO CANYON UNIT 2 0l5l0l0l0l3l2l3 92 0l0l6 0l0 6 l'l9 TEnv (17) to the fire alarm. The SCO incorrectly concluded that work had not been completed on the problem and that the compensatory measures were still in place.
Event 2.
The rcot cause was personnel error due to improper handling of the spurious fire alarm. The fire detector had alarmed twice in a 24-hour period, but was reset and treated as an operable alarm. No continueus fire watch was provided since the control room personnel believed the system was operable.
C.
Contributory Cause:
1.
Event 1.
Undocumented replacement of the plant problem report sticker. The original plant problem report sticker was properly removed by I&C personnel on September 22, 1992, when the work order was completed. On September 23, 1992, a new sticker referencing this plant problem report was placed on the panel.
2.
Event 1.
The most probable cause for the spurious alarms was the labels on the filter modules.
3.
Events 1 and 2.
Because of the numerous spurious alarms associated with fire detectors in the plant, the orgenizations involved have established a practice of tolerating such alarms and not rigorously searching for the causes of spurious alarms.
4.
Events 1 and 2.
The design of the fire alarm system contributed to these events in that the system allows one detector in alarm to render the entire zone inoperaM".
5.
Events 1 and 2.
The fire alarm panels and alarms are normally attended by the control room SCO or the Control Operator (CO).
Information as to whether a compensatory measure was in place was available in the control room (SFM's office), but the control room operators were not aware of this information.
IV.
Analysis of the Event Event 1.
Detection zone B-8 monitors the Unit 2 auxiliary and fuel handling building ventilation areas. The fire loading is 36 minutes of fixed combustibles and 2 minutes of transient combustibles. The fire loading in the zone consists primarily of the carbon filters in two separate trains.
HEPA filters provide most of the remaining fuel.
Primary fire suppression is provided by fire hose reels and backed up by extinguishers (KQ). The equipment located in detection zone B-8 is Epqt required for safe shutdown.
Event 2.
Detection zone B-2 monitors the CCW pump, the charging pump, and the containment spray pump rooms. A fire Natch patrol monitors these rooms each hour on a regular basis. During the time that detection zone B-2 was inoperable, one fire barrier impairment exi;ted between CCW pump rooms 2-2 and 2-3 requiring the continuous fire watch. The maximum fire loading for
i LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199M5 8
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navarm DIABLO CANYON UNIT 2 0l5l0l0l0l3l2l3 92
- 0l0l6 0l0 7 ll9 TEXT (IV) these CCW pump rooms is a maximum of 11 minutes of fixed combustibles and 3 minutes of transient combustibles. The fire loading in these zones consists l
primarily of lubrication oil and cable insulation (VG)(ISL). Should a fire be initiated in one of the CCW pump rooms, it would be quickly extinguished by the automatic wet pipe sprinkler system (KP)(SRNK) that is located in each of the CCW pump rooms. When the sprinkler system is actuated, the
)
remote annunciator alarms in the control room to alert the operators of the fire.
In addition to the above fire suppression, additional fire suppression is provided by portable fire extinguishers and hose stations.
In the event of a fire in zones B-2 or B-8, the ability for safe shutdown is still obtainable; thus, the lack of the fire watch patrol for Event 1 and the continuous fire watch for Event 2 did not adversely affect the health and safety of the public.
V.
Corrective Actions A.
Immediate Corrective Actions:
Event 1.
Upon identifying that the compensatory measure had been removed, the SCO re-established an hourly fire watch patrol.
Event 2.
The SFH reset the alarm.
B.
Corrective Actions to Prevent Recurrence:
1.
Event 1.
On-shift training will be developed and implemented to ensure that plant operators understano the plant problem report / work flow process. The primary-objective of this training will be to allow plant operators to properly decide when to update an existing plant problem report and when to initiate a new plant
)
problem report on any recurring plant problem.
This session will l
also discuss the importance of not installing undocumented plant problem report stickers.
2.
Events 1 and 2.
A policy will be developed and disseminated concerning the appropriate methods to utilize when dealing with spurious fire alarms. This policy will require a maintenance investigation and also initiate a " grace period" where detectors that have exhibited spurious alarms will not be declared operable for some time period following the investigation which determined that the alarm was spurious.
This policy will be incorporated in an appropriate plant procedure.
3.
Events 1 and 2.
An Operations incident summary will L ssued for the missed fire watches that occurred on October 30, 1992 and November 14, 1992, and will clearly state the expectations for-dealing with spurious fire detection alarms.
In7 AC /ACV
LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 199775 DOCKET MUM 6ER (2)
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Events 1 and 2.
Applicable procedures will be revised so that information concerning fire detection system impairments will be available and utilized by the control room operators.
In addition, the following relevant corrective actions were previously identified in LER 1-92-014-00, which was submitted to the NRC on n-tober 7, 1992.
1.
Operations personnel will be retrained on the operation of the. fire detection system, including the alarm process computer as well as the inter-relationship between fire detector zones and fire areas.
The estimated completion date of this corrective action is February 12, 1993.
1 2.
Annunciator Response Procedure PK 10-10 and OP K-2C were revised, effective November 16, 1992, to ensure that compensatory measures are initiated prior to extinguishing the PK 10-10 " Fire Detected" main annunciator light. This corrective action will prevent a recurrence of Event 2.
VI.
Additional Information A.
Failed Components:
None.
B.
Previous LERs on Similar Problems:
LER l-92-008-00, " Violation of TS 3.7.9.2 due to Missed Fire Watch Caused by Personnel Error" l
On June 24, 1992 at 0012 PDT, the action statement for TS 3.7.9.2 was not met for Unit I when the required continuous fire watch was not performed in the required safety-related equipment rooms. The root cause was determined to be personnel error on the part of a licensed SFM.
Upon reviewing the equipment tagout request, the SFM did not identify TS requirements. Corrective actions included (1) counseling the SFM and operators involved in the importance of establishing TS required fire watches and (2) establishing an Operations Coordination Instruction to establish fire watches as the first step on any tagout I
request which renders TS fire protection systems inoperable.
For the current Event 1, the control room personnel identified the TS requirements, but were led to believe that the compensatory measure was in place.
For the current Event 2, the control room personnel were unaware that the alarm for zone B-2 had returned.
Therefore, the previous corrective actions would not have prevented this LER.
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h LICENSEE EVENT REPORT (LER) TEXT CONTINUATION 1o9775 ncautt ame u) oocars me sca ta) ten mmsta 's) nu o>
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LER l-92-014-00, " Violation of TS 3.7.10: Missed Fire Watches due to Personnel Error" j
On September 3rd and 4th, 1992, at 1630 PDT, and on September 15, 1992, at 1032 PDT, the action statement for TS 3.7.10 was not met for Unit 1.
The required continuous fire watch was not in place while detection zone A10 smoke detectors were inoperable and fire barriers were impaired.
?
The root causes were determined to be (1) personnel error (non-cognitive) in that the operations personnel-failed to understand the i
interrelationship between the faulted detection zone and the fire barrier area when interpreting the compensatory measures specified in 4
the TS and (2) personnel error (communication) in that the Unit 2 personnel did not verify that the Unit l' operator fully understood the detection zone A10 alarm status.
Current Event I did not involve the operations pr.;onnel not understanding the fire alarm system capabilities. The control room personnel identified the TS j
requirements, but were led to believe that the compensatory measure was in place.
Therefore, the previous corrective actions would not have prevented Event 1 of this LER. The corrective actions for LER l-92-014-00 are in the process of being implemented.
Had the corrective actions been fully implemented, Event 2 would have been prevented, n
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