Information Notice 1992-69, Water Leakage from Yard Area Through Conduits Into Buildings
UNITED STATES
=
NUCLEAR REGULATORY COMMISSION
OFFICE OF NUCLEAR REACTOR REGULATION
WASHINGTON, D.C.
20555
September 22, 1992
NRC INFORMATION NOTICE 92-69: WATER LEAKAGE FROM YARD AREA THROUGH
CONDUITS INTO BUILDINGS
Addressees
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
The U.S. Nuclear Regulatory Commission is issuing this information notice to
alert addressees to problems resulting from large amounts of water leaking
into the reactor building through electrical conduits.
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
On November 19, 1991, following a thunderstorm, the licensee for the Grand
Gulf Nuclear Station observed a significant amount of rain water entering the
auxiliary building through electrical conduits. Most of the leakage was from
around one condulet cover plate; a number of other condulet cover plates were
dripping water.
The conduits originated in a large manhole located in the
adjacent yard area through which the licensee had routed many electric cables
by way of an underground conduit. The licensee found that the sump pump in
this manhole was not operating, probably because of heavy rainfall on the
circuit box, which tripped the circuit breaker for the pump.
Water then
collected in the manhole and flowed through the conduits which Were routed
into the auxiliary building. These conduits were to have internal seals near
the wall of the auxiliary building and upstream of the leaking condulet cover
plates. The licensee found that some seals were below or downstream of the
condulet cover plates.
Water that leaked from the conduits collected on the
floor, ran through a doorway into the division I switchgear room, and passed
through floor drains to the radwaste collection tank. About 30,000 gallons of
water collected in these tanks.
Water marks indicated the maximum water level
on the floor was about 1 inch.
No safety systems were affected.
On December 22, 1991, a 36-inch fiberglass auxiliary circulating water line
failed at the Perry Nuclear Power Plant.
The failure was in a non-isolable
section located in a yard area above grade just before the line enters the
heater bay building. An estimated 2.9 million gallons of water was pumped out
of the break. A small percentage of this amount entered the auxiliary
9209160134 A
IN 92-69 September 22, 1992 building, the heater bay, the service water pump house, and the emergency
service water (ESW) pump house.
Two electrical manholes had previously leaked
during rains and were not designed to be leak tight against standing water.
Conduits in these manholes formed a direct path into the buildings where the
cables enter. In particular, water entered the ESW pump house through a
series of conduits and ran down a cable into a compartment of a motor control
center (MCC), causing a short circuit in a space heater transformer. This MCC
also contained safety-related equipment, which was not damaged.
Discussion
In both instances, large quantities of water entered buildings and areas
within the buildings that contain safety-related equipment.
The leak path
through yard manholes and connecting electrical conduits was not explicitly
considered in the safety analysis. At Grand Gulf, although seals installed in
manholes and conduits were not required to be leak tight against water intru- sion, the licensee found them to be deficient with respect to a design
drawing.
These conduits were sealed. The licensee for Perry also sealed the
conduits.
The licensees did not inspect seals or perform tests that would
detect the absence or deterioration of installed seals.
This information notice requires no specific action or written response. If
youi-ave any questions about the in'formation in this n-oti'-e,-pleasecontact
~-
the technical contact listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
Charles E. Rossi, Director ; r
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: J. Carter, NRR
(301)
504-1153 Attachment:
List of Recently Issued NRC Information Notices
K-I
Attachment
September 22, 1992
Page 1 of I
LIST OF RECENTLY ISSUED
NRC INFORMATION NOTICES
Information
Date of
Notice No.
Subject
Issuance
Issued to
91-29, Supp. 1
92-68
92-67
Deficiencies Identified
During Electrical Dis- tribution System Func- tional Inspections
Potentially Substandard
Slip-On, Welding Neck, and Blind Flanges
Deficiency in Design
Modifications to Ad- dress Failures of
Hiller Actuators Upon
A Gradual Loss of
Air Pressure
09/14/92
09/10/92
09/10/92
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 nuclear power reactors.
92-66
- -Access-Denied to NRC
Inspectors at Five Star
Products, Inc. and
Construction Products
Research, Fairfield, Connecticut
09/01/92 All holders-of-OLs or CPs
for nuclear power reactors
and all recipients of
NUREG-0040, "Licensee, Con- tractor and Vendor Inspec- tion Status Report" (White
Book).
92-65
92-64
92-63
Safety System Problems
Caused by Modifications
That Were Not Adequately
Reviewed and Tested
Nozzle Ring Settings
on Low Pressure Water-
Relief Valves
Cracked Insulators in
ASL Dry Type Transformers
Manufactured by Westing-,
house Electric Corporation
Emergency Response
Information Require- ments for Radioactive
Material Shipments
09/03/92
08/28/92
08/26/92
08/24/92
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 nuclear power reactors.
All U.S. Nuclear Regulatory
Commission licensees.
92-62 OL = Operating License
CP = Construction Permit
IN 92-69 September 22, 1992 building, the heater bay, the service water pump house, and the emergency
service water (ESW) pump house.
Two electrical manholes had previously leaked
during rains and were not designed to be leak tight against standing water.
Conduits in these manholes formed a direct path into the buildings where the
cables enter.
In particular, water entered the ESW pump house through a
series of conduits and ran down a cable into a compartment of a motor control
center (MCC), causing a short circuit in a space heater transformer. This MCC
also contained safety-related equipment, which was not damaged.
Discussion
In both instances, large quantities of water entered buildings and areas
within the buildings that contain safety-related equipment. The leak path
through yard manholes and connecting electrical conduits was not explicitly
considered in the safety analysis.
At Grand Gulf, although seals installed in
manholes and conduits were not required to be leak tight against water intru- sion, the licensee found them to be deficient with respect to a design
drawing. These conduits were sealed.
The licensee for Perry also sealed the
conduits.
The licensees did not inspect seals or perform tests that would
detect the absence or deterioration of installed seals.
This information notice requires no specific action or written response. If
you have any questions about the information in this notice, please contact
the technical contact listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
Orig /s] 'd by CItirmes
Char es
. Ro si, irector
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: J. Carter, NRR
(301) 504-1153 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
OFC
OEAB:DOEA
ADM:RPB
SC/OEAB:DOEA PD3-3:ADR3 NAME
JCarter*
JMain*
RDennig*
JHall*
DATE
07/01/92
07/06/92
07/13/92
07/09/92 OFC
PD4-1:ADR4-5 C/OEAB:DOEA
C/OGCB:DOEA
D/DOEA
A
NAME
PO'Connor*
AChaffee*
GHMarcus*
CRossi
DATE
07/09/92
07/13/92
09/15/92
09/ 3/92
OFFICIAL RECORD COPY
DOCUMENT NAME: 92-69.IN
111 IN 92-XX
September xx, 1992 Conduits in these manholes formed a direct path into the buildings where the
cables enter.
In particular, water entered the ESW pump house through a
series of conduits and ran down a cable into a compartment of a motor control
center (MCC), causing a short circuit in a space heater transformer. This MCC
also contained safety-related equipment, which was not damaged. Corrective
actions included sealing conduits to preclude future leakage.
Discussion
In both instances, large quantities of water entered buildings and areas
within the buildings that contain safety-related equipment.
The leak path
through yard manholes and connecting electrical conduits was not explicitly
considered in the safety analysis.
At Grand Gulf, although seals installed in
manholes and conduits were not required to be leak tight against water intru- sion, the licensee found them to be deficient with respect to a design
drawing.
These conduits were sealed.
The licensee for Perry also sealed the
conduits.
The licensees did not inspect seals or perform tests that would
detect the absence or deterioration of installed seals.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact: J. Carter, NRR
(301) 504-1153 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
OFC
JOEAB:DOEA
ADM:RPB
SC/OEAB:DOEA PD3-3:ADR3 NAME
lJCarter*
JMain*
RDennig*
JHall*
07/01/92
07/06/92
07/13/92
07/09/92 OFC
PD4-1:ADR4-5 C/OEAB:DOEA
C/OGCB:DOEA
D/DOEA
NAME
PO'Connor*
AChaffee*
u
CI
CRossill
DATE
07/09/92
07/13/92
1 //5/92
/ /92
OFFICIAL RECORD COPY
DOCUMENT NAME:
C:\\WTRLEAK.R1 (ATB)
IN 92-XX
July xx, 1992 Conduits in these manholes formed a direct path into the buildings where the
cables enter.
In particular, water entered the ESW pump house through a
series of conduits and ran down a cable into a compartment of a motor control
center (MCC), causing a short circuit in a space heater transformer. This MCC
also contained safety-related equipment, which was not damaged.
Corrective
actions included sealing conduits to preclude future leakage.
Discussion
In both instances, large quantities of water entered buildings and areas
within the buildings that contain safety-related equipment.
The leak path
through yard manholes and connecting electrical conduits was not explicitly
considered in the safety analysis.
The licensees apparently did not inspect
all seals installed during construction. Any seals installed in manholes and
conduits were not required to be leak tight against water intrusion.
The
licensees do not routinely inspect seals and do not perform any tests that
would detect the absence or deterioration of installed seals.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact:
J. Carter, NRR
(301) 504-1153 Attachment:
List of Recently Issued NRC Information Notices
- SEE PREVIOUS CONCURRENCES
OFC
OEAB:DOEA
ADM:RPB
SC/OEAL
DOEA PD3-3:ADR3 NAME
JCarter*
JMain*
JHall*
[DATE I
07/01/92
07/06/92
1 I/1 92
07/09/92 OFC
PD4-1:ADR4-5 .
ifC/OGCB:DOEA ifD/DOEA
NAME
PO'Connor*
af
V 6e4
CBerlinger l CRossi
D
07/09/92
1 / I92
/
/92
[
/
/92 OFIIA
OP
OCMN NM:
- WRLA
(TB
OFFICIAL RECORD COPY
DOCUMENT NAME:
C:\\WTRLEAK
(ATB)
IN 92-XX
June xx, 1992 entered the (ESW) pump house through a series of conduits and ran down a cable
into a compartment of a motor control center (MCC), causing a space heater
transformer to short. This MCC also contained safety related equipment which, however, was not damaged.
Corrective actions included sealing conduits to
preclude future leakage.
Discussion
In both instances large quantities of water entered buildings and areas within
the buildings that contain safety related equipment.
The leak path, ie., via
yard manholes and connecting electrical conduits, was not explicitly consid- ered in the safety analysis.
Inspection of seals installed during construc- tion does not appear to have been comprehensive.
Any seals installed in
manholes and conduits were not required to be leak tight against water intru- sion.
The seals are not routinely inspected nor is any testing done that
would detect the absence or deterioration of installed seals.
This information notice requires no specific action or written response.
If
you have any questions about the information in this notice, please contact
the technical contacts listed below or the appropriate Office of Nuclear
Reactor Regulation (NRR) project manager.
Charles E. Rossi, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical contact:
J. Carter, NRR
(301) 504-1153 Attachment:
List of Recently Issued NRC Information Notices
OFC
jf _EA
ADM:RPB
SC/OEAB:DOEA
PD3-3:ADR3 NAME
art
JMain 9T
RDennig
JHall
DATE
/1/92
7/G /92
/ /92
7/7/92 OFC
PD4-1:ADR4-5 C/OEAB:DOEA
C/OGCB:DOEA
D/DOEA
NAME
PO'Connor
¶
AChaffee
CBerlinger
CRossi
DATE
2
/c9/92
/ /92 I/ /92
/ /92
OFFICIAL RECORD COPY
DOCUMENT NAME:
C:\\WTRLEAK
(ATB)