Information Notice 1993-47, Unrecognized Loss of Control Room Annunciators
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C.
20555
June 18, 1993
NRC INFORMATION NOTICE 93-47: UNRECOGNIZED LOSS OF CONTROL
ROOM ANNUNCIATORS
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
PurDose
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information
notice to alert addressees to the potential problem of unrecognized loss of
control room annunciators.
It is expected that recipients will review the
information for applicability to their facilities and consider actions, as
appropriate, to avoid similar problems. However, suggestions contained in
this information notice are not NRC requirements; therefore, no specific
action or written response is required.
Description of Circumstances
Callaway
On October 16, 1992, while the Callaway Plant was operating at 100 percent
power, approximately 75 annunciators on the main control board illuminated.
After verifying that the annunciators were not valid, the shift supervisor
(SS) notified the plant manager and the engineering duty officer of the
condition and requested instrumentation and control (I&C) technicians to begin
repairs. The I&C technicians found that one of four field power supplies for
the annunciators had failed. The failed power supply was replaced and the
annunciators appeared to return to normal.
Two minutes later, while removing
jumper cables installed during the replacement, an electrical short occurred.
In the control. room, 371 of the 463 main control board annunciators
illuminated and remained lit. The I&C technicians inspected the power
supplies and determined that the output fuses for all four field power
supplies had blown.
The blown fuses resulted in the loss of all main control
board annunciators.
This was not recognized by the plant staff.
Callaway procedure EIP-ZZ-00101, "Classification of Emergencies," describes
those conditions which constitute entry into established emergency action
levels (EALs). The procedure states that, for an initiating condition of
"Most or All Alarms (Annunciators) Lost," the proper emergency classification
is an Alert.
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IN 93-47 June 18, 1993 Approximately one hour after the loss of all annunciators, the blown output
fuses were replaced and power was restored to the annunciator system.
Plant
personnel verified that power was available to the annunciators by depressing
test switches in the control room.
However, this did not test the annunciator
logic circuitry and, as a result, the operating crew was unaware that
164 annunciators with re-flash capability were completely inoperable.
Apparently, the short that blew the output fuses in the field power supplies
also blew fuses in eight annunciator logic power supplies. Later, while
investigating problems with the annunciators, the I&C engineer found and
replaced the blown fuses in the eight logic power supplies and an appropriate
test was performed.
However, there was not an approved procedure for this
test nor was it properly documented.
By 7:37 p.m. on October 17 the main
control board annunciators had been restored to fully operable status.
Because the SS failed to recognize that all of the main control board
annunciators were inoperable after the four field power supply output fuses
had blown, an Alert was not declared on October 17, 1992.
On October 19, the
licensee determined that an Alert should have been declared and notified State
and local authorities and the NRC of the event.
Inspection of this event by an NRC Augmented Inspection Team (AIT) found the
following weaknesses: (1) insufficient knowledge of the annunciator system by
the plant staff, (2) poor communications and inadequate teamwork, (3) lack of
a questioning attitude, and (4) inadequate work performance. Contributing to
the insufficient- knawledge--of-the--annuncl-ator- system wa-rthbefattir
an off-normal operating procedure or other procedure that addressed loss of
Salem Unit 2
On December 13, 1992, control room operators at Salem Unit 2 Nuclear Station
discovered that the overhead annunciators had been inoperable for about
90 minutes.
The inoperable condition was detected when an alarm printer
printed a change in alarm status which was not reflected by the overhead
The operators reset the annunciator system and restored it to
operable status within two minutes.
Subsequent inspection of the event by an
NRC AIT identified several weaknesses that contributed to the problem. The
operators were not adequately trained to verify proper operation of a recently
installed micro-processor based annunciator system.
The new system was not
designed with annunciation as a priority task and therefore it did not
indicate a critical mispositioned switch.
Attempts by the operators to enter
files, despite a procedure caution, contributed to locking up the system.
The
plant staff delayed in notifying plant management and the NRC.
The licensee
did not have a procedure to deal with the loss of annunciators. The AIT
concluded that the overall knowledge of the system was inappropriate for a
system that, if lost, required the declaration of an Alert.
June 18, 1993 Discussion
Although plant annunciators are not considered safety related, they are
important for the safe operation of a nuclear power plant.
Further, an
unrecognized loss of annunciators may increase the difficulty of diagnosing
problems in plant operations and equipment. In order for plant operators to
recognize and respond properly to a loss of annunciators, it is important to
have clear procedures, appropriate training, and effective communications
between operators and plant support personnel.
For the events described
above, an off-normal operating procedure that clearly stated required actions
would have significantly aided the operators to diagnose the extent of the
problem, take necessary response actions, and make required notifications.
Loss of annunciator events were covered by the emergency classification
procedures of both licensees, premised upon guidance of Appendix 1 of
NUREG-0654/FEMA-REP-1, "Criteria for Preparation and Evaluation of.
Radiological Emergency Response Plans and Preparedness in Support of Nucleae
Power Plants," (November 1980).
The NRC recently issued Revision 3 to
"Emergency Planning and Preparedness for Nuclear Power
Reactors" (August 1992).
That revision endorsed NUMARC/NESP-007, Revision 2,
"Methodology for Development of Emergency Action Levels," (January 1992), as
an acceptable alternative.
With respect to loss of annunciators, the
NUMARC/NESP-007 guidance provides an alternative delineation of thresholds for
declaring an Unusual-Event, Alert or-Site Area Emergency.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Bruce L. Bartlett, RIII
(314) 676-3181
Rolf A. Westberg, RIII
(708) 790-5776
Scott A. Boynton, NRR
(301) 504-2926 Attachment:
List of Recently Issued NRC Information Notices
It '
J.
s
t
Attachment
June 18, 1993
Page I of 1
LIST OF RECENTLY ISSUED
NRC IHFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
93-46 Potential Problem with
6/10/93
All holders of OLs or CPs
Westinghouse Rod Control
for Westinghouse (W)-
System and Inadvertent
designed nuclear power
Withdrawal of A Single
reactors.
Rod Control Cluster Assembly
93-45 Degradation of Shutdown
06/16/93
All holders of OLs or CPs
Cooling System Performance
for nuclear power reactors.
93-44 Operational Challenges
06/15/93
All holders of OLs or CPs
During A Dual-Unit
for nuclear power reactors.
93-43 Use of Inappropriate
06/10/93
All holders of OLs or CPs
Lubrication Oils In
for nuclear power reactors.
Safety-Related Applications
93-42 Failure of Anti-Rotation
06/09/93
All holders of OLs or CPs
Keys in Motor-Operated
for nuclear power reactors.
Valves Manufactured by
Velan
93-41 One Hour Fire Endurance
05/28/93
All holders of OLs or CPs
Test Results for Thermal
for nuclear power reactors.
Ceramics Kaowool, 3N
Company FS-195 and
3M Company Interam E-50
Barrier Systems
93-40
Fire Endurance Test
05/26/93
All holders of OLs or CPs
Results for Thermal
for nuclear power reactors.
Ceramics FP-60 Fire
Barrier Material
93-39 Radiation Beams from
05/25/93
All holders of OLs or CPs
Power Reactor Biolog- for nuclear power reactors.
ical Shields
oL - Operating License
CP - Construction Permit
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IN 93-XX
May xx, 1993 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Bruce L. Bartlett, Region III
(314) 676-3181
Rolf A. Westberg, Region III
(708) 790-5776
Scott A. Boynton, NRR
(301) 504-2926 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCE
- RPB:ADM
RSanders
03/17/93
- OGCB:DORS:NRR
JBirmingham
05/06/93 C/OGCB:DORS:NRR
GHMarcusgil
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5/.2'7/93 D/DORS/NRR
BKGrimes
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05/
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- R/RIII
BBartlett
04/21/93
- RIII
RWestberg
04/22/93
- PEPB:DRSS:NRR
SABoynton
05/04/93
- OEAB:DORS:NRR
TKoshy
05/05/93 DOCUMENT NAME: ANNUNCEB.JLB
IN 93-XX
May xx, 1993 This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Bruce L. Bartlett, Region III
(314) 676-3181
Rolf A. Westberg, Region III
(708) 790-5776 Scott
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% A. Boynton, NRR
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List of Recently Issued NRC Information Notices PA
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Attachment:
- RPB:ADM
RSanders
03/17/93
- R/RIII
BBartlett
04/21/93 OGCB:DORS:NRR
JBirmingham.
05/ a /93
/:
C/OGCB:DORS:NRR
GHMarcus
05/ /93 D/DORS/NRR
BKGrimes
05/ /93 RI I J})M'
RWestbeVg
ANNUNCE8.JLB
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05/& /93 OEAB:DO :NRR
TKoshydi
05/5 /9 DOCUMENT NAME:
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3 have clear procedures, appropriate training, and effective communications
between operators and plant support personnel.
For the events described
above, an off-normal operating procedure that clearly stated required actions
would have significantly aided the operators to diagnose the extent of the
problem, take necessary response actions, and make required notifications.
The NRC recently issued Revision 3 to Regulatory Guide 1.101,
"Emergency
Planning and Preparedness for Nuclear Power Reactors."
That revision
endorsed NUMARC/NESP-007, Revision 2, "Methodology for Development of
Emergency Action Levels," as an acceptable alternative to the method described
in Appendix 1 of NUREG-0654/FEMA REP-1, "Criteria for Preparation and
Evaluation of Radiological Emergency Response Plans and Preparedness in
Support of Nuclear Power Plants." NUMARC/NESP-007 provides guidance that more
clearly delineates the thresholds for declaration of an Unusual Event, Alert
and Site Area Emergency.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Brian K. Grimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts: Bruce L. Bartlett, Region III
(314) 676-3181
Rolf A. Westberg, Region III
(708) 790-5776
Scott A. Boynton, NRR
(301) 504-2926 Attachment:
List of Recently Issued NRC Information Notices
- RPB:ADM
OGCB:DORS:NRR
C/OGCB:DORS:NRR
D/DORS/NRR
RSanders
JBirmingham
GHMarcus
BKGrimes
03/17/93
04/
/93
04/
/93
04/ /93
- R/RI II / 4 RlIl
m
PEPB:DRSS:NRR
OEAB:DORS:NRR
BBartlett
RWest erg
SABoynton
TKoshy
04/21/93
04/XR./93
04/ /93
04/ /93 DOCUMENT NAME:
ANNUNCE8.JLB
-~
~
June 18, 1993 Discussion
Although plant annunciators are not considered safety related, they are
important for the safe operation of a nuclear power plant.
Further, an
unrecognized loss of annunciators may increase the difficulty of diagnosing
problems in plant operations and equipment.
In order for plant operators to
recognize and respond properly to a loss of annunciators, it is important to
have clear procedures, appropriate training, and effective communications
between operators and plant support personnel.
For the events described
above, an off-normal operating procedure that clearly stated required actions
would have significantly aided the operators to diagnose the extent of the
problem, take necessary response actions, and make required notifications.
Loss of annunciator events were covered by the emergency classification
procedures of both licensees, premised upon guidance of Appendix 1 of
NUREG-0654/FEMA-REP-1, "Criteria for Preparation and Evaluation of
Radiological Emergency Response Plans and Preparedness in Support of Nuclear
Power Plants," (November 1980).
The NRC recently issued Revision 3 to
"Emergency Planning and Preparedness for Nuclear Power
Reactors" (August 1992).
That revision endorsed NUMARC/NESP-007, Revision 2,
"Methodology for Development of Emergency Action Levels," (January 1992), as
an acceptable alternative. With respect to loss of annunciators, the
NUMARC/NESP-007 guidance provides an alternative delineation of thresholds for
declaring an Unusual Event, Alert or Site Area Emergency.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
one of the technical contacts listed below or the appropriate Office of
Nuclear Reactor Regulation (NRR) project manager.
Original signed by
MI-(. 'rimes, Director
Division of Operating Reactor Support
Office of Nuclear Reactor Regulation
Technical contacts:
Bruce L. Bartlett, RIII
(314) 676-3181
Rolf A. Westberg, RIII
(708) 790-5776
Scott A. Boynton, NRR
(301) 504-2926 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCE
- RPB:ADM
- OGCB:DORS:NRR
- C/OGCB:DORS:NRR
RSanders
JBirmingham
GHMarcus
mes
03/17/93
05/06/93
05/27/93
05,/l 93
- R/RIII
- RIII
- PEPB:DRSS:NRR
- OEAB:DORS:NRR
BBartlett
RWestberg
SABoynton
TKoshy
04/21/93
04/22/93
05/04/93
05/05/93 DOCUMENT NAME:
93-47.IN