Information Notice 1990-69, Adequacy of Emergency and Essential Lighting
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C.
20555
October 31, 1990
NRC INFORMATION NOTICE NO. 90-69: ADEQUACY OF EMERGENCY AND ESSENTIAL LIGHTING
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
This information notice is intended to alert addressees to a possible problem
concerning the adequacy of emergency and essential lighting at commercial power
reactor facilities. 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 do not constitute NRC requirements; therefore, no specific action or
written response is required.
i
Description of Circumstances
On March 3, 1989, Unit 3 at the Palo Verde Nuclear Generating Station experi- enced a reactor/turbine trip, main steam isolation, containment isolation, and
safety injection as a result of a grid-induced load rejection event. This
event included three significant system failures: (1) half of the steam bypass
control system malfunctioned; (2) the atmospheric dump valves (ADYs) failed to
operate from the control room and the remote shutdown panel; and (3) the
emergency lighting in the main steam support structure (MSSS) failed, hampering
the operators in their attempt to cope with the ADY failures.
Being unable to
maintain pressure control on the secondary side by operating the ADVs from the
control room or the remote shutdown panel, plant personnel attempted to establish
local (manual) control of the ADYs in the MSSS. When operators first entered
the MSSS, they found no direct lighting.
Normal lighting was lost due to the
loss of power to the non-Class 1E electrical busses in the plant. The emergency
lighting was not properly positioned in the north MSSS room (containing the
ADVs for the No. 1 steam generator) to provide adequate lighting for the
operators to perform their required activities and was not functioning at all
in the south MSSS room (containing ADVs for the No. 2 steam generator).
Because of a burned-out light bulb, plant personnel could not restore essential
lighting (from Class 1E power sources) in the south MSSS room.
"C-
(
01200543
IN 90-69 October 31, 1990 During the NRC inspection (50-530/89-13) conducted by an augmented inspection
team (AIT)
sent to examine the event at Palo Verde, the staff found deficien- cies in the licensee's maintenance and testing of emergency and essential
lighting. The team discovered that plant personnel had waived the quarterly
preventive maintenance (PM) tasks on the MSSS emergency and essential lights
for five consecutive quarters.
By grouping the lights in the MSSS with the
lights in the containment building, which were inaccessible during power
operations, the PM tasks were waived for the MSSS lights during each of these
periods along with the containment lights.
NRC inspections further revealed
that the licensee, prior to the performance of the 8-hour lighting unit dis- charge test, performed preventive maintenance (i.e., battery replacement, addition of electrolyte, cleaning of battery terminals, and battery charging)
on the lighting unit battery.
This preventive maintenance practice resulted
in not verifying the performance of the 8-hour emergency lighting units in the
Was found" condition. The inspections also revealed that the licensee had
failed to implement the relevant portions of its quality assurance program for
Because of these failures, the emergency lighting was not
properly tested, and deficiencies were not properly corrected.
After the event, plant personnel reconstructed the design bases of the
lighting system and conducted walkdown inspections of the emergency and essen- tial lighting in the plant. In some instances, the licensee found the lighting
to be inadequate to perform the required tasks because the original design did
not require emergency lights or because the emergency lights provided inade- quate illumination. In addition, the licensee identified many areas that
required the installation of or modification to lighting to meet the licensee's
design bases and the requirements in 10 CFR Part 50 Appendix R.
Background
At Palo Verde, the essential lighting system is an integral part of the normal
lighting system that provides illumination if the normal lighting system fails.
The essential lighting system is rated non-Class lE but is powered from
Class lE sources. The system provides lighting in the control room, in the
shutdown panel area, in the main walkways and stairs, in the Class lE switchgear
rooms, in areas having Class lE equipment, and in areas used for the safe
shutdown of the reactor. Upon loss of the normal lighting system, the essential
lighting system provides adequate illumination for the safe shutdown of the
reactor. The system receives power from two redundant and independent Class 1E
ac busses.
Each redundant Class 1E ac bus supplies power to 50 percent of the
essential lighting in the vital areas. The diesel generators provide backup
power.
IN 90-69 October 31, 1990 The emergency lighting system receives dc power from two redundant Class lE
batteries through inverters and provides illumination for the control room, the auxiliary electrical equipment rooms, the stairways, and the points leading
to plant exits. The system is normally deenergized and is automatically
energized upon loss of ac power to the normal system. The emergency lighting
system is also composed of 8-hour and li-hour (individually battery-powered)
emergency lighting units. The 8-hour emergency lighting units are designed to
meet the technical requirements of 10 CFR 50 Appendix R, Section III.J which
requires that emergency lighting units with at least an 8-hour battery power
supply be provided in all areas needed for operation of safe shutdown equipment
and in access and egress routes thereto. The li-hour emergency lighting units
are installed to meet the requirements of the Life Safety Code. These lighting
units are generally installed in plant locations to accommodate the safe
evacuation of personnel in the event of a fire in such areas.
Discussion:
During the Palo Verde event, the inadequate lighting conditions significantly
complicated the licensee's efforts to cope with the initial failure of the
ADVs, which delayed the commencement of the controlled removal of decay heat as
called for by the emergency operating procedures.
It is important to note that adequate PM and routine testing programs for
essential and emergency lighting systems are helpful in ensuring adequate
illumination for the operation of safe shutdown equipment. Emergency lighting
is a key fire protection feature associated with supporting post-fire safe
shutdown operations.
The exercise of good engineering design practices that
conform to industry standards ensures the ability of the lighting system to
provide adequate station lighting in all vital areas during all types of
accident or transient conditions. The implementation of an effective PM and
testing program which demonstrates lighting system operability is important.
Emergency lighting PM programs recommended by manufacturers generally include
routine monitoring of the battery condition for each lighting unit, periodic
load testing to verify that the lighting unit and its associated charger are
functioning properly, and a periodic "as found" 8-hour lighting unit discharge
test. In addition, the Palo Verde event identified that the inadvertent
repositioning of the emergency lighting fixtures can cause inadequate illumina- tion and that routine verification of emergency lighting fixture orientation
can ensure that emergency lighting is effective.
IN 90-69 October 31, 1990 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 NRR project manager.
Charles E. Rossi,'rectoor
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts: N. K. Trehan, NRR
(301) 492-0777
S. R. Peterson, NRR
(301) 492-3062 Attachment: List of Recently Issued NRC Information Notices
Attachment 1
October 31, 1990 LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
90-68
90-67
90-66
Stress Corrosion Cracking
of Reactor Coolant Pump Bolts
Potential Security Equipment
Weaknesses
Incomplete Draining and
Drying of Shipping Casks
High Radiation Hazards
From Irradiated Incore
Detectors and Cables
Recent Orifice Plate
Problems
Potential for Common-Mode
Failure Of High Pressure
Safety Injection Pumps or
Release of Reactor Coolant
Outside Containment During
A Loss-Of-Coolant Accident
Management Attention to the
Establishment and Main- tenance of A Nuclear
Criticality Safety Program
10/30/90
10/29/90
10/25/90
10/5/90
10/5/90
10/4/90
10/3/90
88-63, Supp. 1
90-65
90-64
90-63
All holders of OLs
or CPs for pres- surized water
reactors (PWRs).
All holders of OLs
or CPs for
nuclear power
reactors and
Category I fuel
facilities.
All holders of OLs
for nuclear
power reactors
and all registered
users of NRC
approved waste
shipping packages.
All holders of OLs
or CPs for nuclear
power reactors.
All holders of OLs
or CPs for nuclear
power reactors.
All holders of OLs
or CPs for pres- surized-water
reactors.
All fuel cycle
licensees possess- ing more than
critical mass
quantities of
special nuclear
material.
OL = Operating License
CP = Construction Permit
IN 90-69 October 31, 1990 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 NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
N. K. Trehan, NRR
(301) 492-0777
S. R. Peterson, NRR
(301) 492-3062 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
C/OGCB:DOEA:NRR
- CHBerlinger
10/18/90
RPB:ADM
- TechEd
10/18/90
AD/AD45
- BABoger
10/09/90
D/PD5 PD5:DRSP:NRR
- JEDyer
- SRPeterson
10/09/90
09/24/90
OGCB:DOEA:NRR
- PCWen
09/24/90
SELB:DST:NRR
- NKTrehan
09/24/90
C/SELB:DST:NRR
- FRosa
09/25/90
C/SPLB:DST:NRR
- CMcCracken
10/03/90
D/DST: NRR
- AThadani
10/03/90
DOCUMENT NAME: IN 90-69
IN 90-XX
October xx, 1990 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 NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
N. K. Trehan, NRR
(301) 492-0777
S. R. Peterson, NRR
(301) 492-3062 Attachment:
List of Recently Issued NRC Information Notices
Document Name:
INADQUATE LIGHTING
- SEE PREVIOUS CONCURRENCES
D/DOEA:NRR
CERossitt
col/o9 J
I
RPB:AD
A
D/A5A9"e
CHB
e
TEd
j
h
ABoger
EDyer
10/10/990
O
M l
91O/q
/9,
- OGC :DOEA:F
R
- SELB:DST:NRR *C/SELB:DST:yRg /SPLB:DST:NRR
PCWen
NKTrehan
FRosa
( IWCMcCracken
09/24/90
09/24/90
09/25/90 '
1 og /90
- PD5:DRSP:NRR
SRPeterson
09/24/90
/
t10(s
IN 90-XX
September xx, 1990 Discussion:
During the Palo Verde event, the inadequate lighting conditions significantly
complicated the licensee's efforts to cope with the initial ADVs failure.
However, the plant personnel were eventually able to open two ADVs and, thereby, commence a controlled removal of decay heat as called for by the
emergency operating procedures.
Other plants may also have inadequate PM programs for the emergency and the
essential lighting systems and may provide inadequate illumination for the
operation of safe shutdown equipment. This event also points out that the
inadvertent repositioning of emergency lighting units can cause inadequate
illumination.
By verifying the orientation of these units, the licensees can
ensure that the lights are positioned properly.
Emergency lighting is a key fire protection feature for the operation of the
safe shutdown equipment. Appendix R to 10 CFR Part 50 requires 8-hour
emergency lighting units in areas used for the operation of safe shutdown
equipment and in access and egress routes thereto. The staff relies on the
exercise of good engineering design practice and design criteria that conform
to industry standards to ensure the ability of the lighting system to provide
adequate station lighting in all vital areas during all types of accident or
transient conditions and in the access routes to and from these areas.
This information notice requires
you have any questions about the
of the technical contacts listed
no specific action or written response. If
information in this notice, please contact one
below or the appropriate NRR project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contacts:
N. K.
(301)
Trehan, NRR
492-0777
S. R. Peterson, NRR
(301) 492-3062 Attachment:
List of Recently Issued NRC Information Notices
Document Name:
INADQUATE LIGHTING
D/DOEA:NRR
CERossi
09/
/90
OGCB:DOEA:NRR
PCWen Fcv'
09/a4/ 9O
C/OGCB:DOEA:NRR
CHBerlinger
09/
/90
SELB:DST:NRR
NKTrehanJLS
09/ A/90
RPB:ADM
TechEd
09/
/90
C/SELB : IRR
FRo
094S9 AD/AD45 BABoger
09/
/9OqJ2s
D/DST:NRRrt t'
AThadani
09/
/90
D/PD5 JEDyer
09/
/90
PD5:DRSP:NRR
SRPeterso e
o9,o/90
C/S P s13 sT :PJR
Ce EmcctfcKW
Document Name:
INADQUATE LIGHTING
Requestor's ID:
WERTMAN
Author's Name:
peter wen
Document Comments:
S34 information notice