Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
ACCESSION #: 9611200167
Initial 10 CFR 21 Notification
NUS Summator and Isolator Modules
I. NAME AND ADDRESS OF THE INDIVIDUAL(S) INFORMING THE COMMISSION.
NAME: E. C. Simpson
Senior Vice President - Nuclear Engineering
ADDRESS: Public Service Electric and Gas Company
P.O. Box 236
Hancock's Bridge, NJ 08038
II. IDENTIFICATION OF THE FACILITY, ACTIVITY OR COMPONENT WHICH FAILS
TO
COMPLY OR CONTAINS A DEFECT.
The facility is the Salem Generating Station, Unit 2. The basic
components are Reactor Control and Protection System signal isolator
and signal summator modules.
III. IDENTIFICATION OF THE FIRM SUPPLYING THE BASIC COMPONENT WHICH
FAILS
TO COMPLY OR CONTAINS A DEFECT.
The modules were manufactured by:
NUS
P.O. Box 50736
Idaho Falls, ID 83405
IV. NATURE OF THE DEFECT OR FAILURE TO COMPLY AND THE SAFETY HAZARD
WHICH IS CREATED OR COULD BE CREATED.
NUS Model OCA801 signal isolator modules and Model MTH 801 Signal
Summator Modules are being installed as replacements for modules in
the Reactor Control and Protection System to provide improved
reliability. During bench testing, an electrical connection with no
solder was observed on a replacement summator module. All
replacement summator and isolator modules for Salem Unit 2 were then
inspected. Ten (of 222) modules were found to have unsoldered
electrical connections. Another seven modules were found to have
insufficient solder on at least one connection. Some of the
defective connections were covered by heat shrink insulation.
The isolator modules function to provide electrical separation
between the Reactor Protection System (Class 1E) and the Process
Control System (non-Class 1E) portions of the Reactor Control and
Protection (RCP) instrument loops. The summator modules are used to
algebraically combine analog signals, either adding or subtracting
inputs in combination with module gain and bias. The summators
accept up to four inputs and provide one summed and isolated output.
The reactor protection system is designed to assure that the system
can perform its required functions in the event of a design basis
earthquake. The defect could affect the modules' ability to function
during a design basis earthquake. It could result in a loss of
redundancy sufficient to constitute a major degradation of essential
safety related equipment.
V. THE DATE ON WHICH THE INFORMATION OF SUCH DEFECT OR FAILURE TO
COMPLY WAS OBTAINED.
The information was obtained on June 28, 1996.
VI. IN THE CASE OF A BASIC COMPONENT WHICH CONTAINS A DEFECT OR FAILS
TO
COMPLY, IDENTIFY THE NUMBER AND LOCATION OF ALL SUCH COMPONENTS
IN
USE AT OR SUPPLIED FOR PSE&G FACILITIES SUBJECT TO THE REGULATIONS
OF 10 CFR 21.
222 replacement modules are being installed in the Salem Unit 2
Reactor Control and Protection System. The replacement modules for
Salem Unit 1 have been returned to the vendor.
VII. THE CORRECTIVE ACTION WHICH HAS BEEN, IS BEING, OR WILL BE TAKEN;
THE NAME OF THE RESPONSIBLE INDIVIDUAL OR ORGANIZATION; AND THE
LENGTH OF TIME THAT HAS BEEN OR WILL BE TAKEN TO COMPLETE THE
ACTION.
All replacement modules for Salem Unit 2 have been inspected by the
vendor and repaired. All replacement modules for Salem Unit 1 have
been returned to the vendor for inspection and repair.
PSE&G is investigating the cause of the defect with the vendor.
Results will be provided when the investigation is complete.
VIII. ANY ADVICE RELATED TO THE DEFECT OR FAILURE TO COMPLY THAT HAS
BEEN, IS BEING, OR WILL BE GIVEN TO PURCHASERS OR LICENSEES.
None.
NRC DATA SHEET
(Page 1 of 2)
NOTIFICATION TIME FACILITY OR ORGANIZATION UNIT CALLER'S NAME
TELEPHONE NUMBER (FOR CALL BACK)
EVENT TIME & ZONE EVENT DATE EVENT CLASSIFICATION (Check One)
GENERAL EMERGENCY * 1HR 10CFR50.72(b)(1)
( )
POWER/MODE POWER/MODE
BEFORE AFTER SITE AREA EMERGENCY * 4HR 10CFR50.72(b)(2)
( )
ALERT 1HR SECURITY/
SAFEGUARDS
UNUSUAL EVENT TRANSPORTATION EVENT
OTHER:
* FOR NON-EMERGENCIES PROVIDE THE
SPECIFIC SUBPART NUMBER OF THE
10CFR50.72 REPORTING REQUIREMENT FROM
THE ECG INITIATING CONDITION
STATEMENT.
EVENT DESCRIPTION
Include In accordance with 10 CFR 21.21(d)(3)(i), the attached initial
notification is provided on the NUS Summator and isolator
modules. NUS Model OCA801 signal isolator modules and Model
MTH 801 Signal Summator Modules are being installed as
replacements for modules in the Reactor Control and Protection
System to provide improved reliability. During bench testing,
an electrical connection with no solder was observed on a
replacement summator module. All replacement summator and
isolator modules for Salem Unit 2 were then inspected. Ten (of
222) modules were found to have unsoldered electrical
connections. Another seven modules were found to have
insufficient solder on at least one connection. Some of the
defective connections were covered by heat shrink insulation.
The isolator modules function to provide electrical separation
between the Reactor Protection System (Class 1E) and the
Process Control System (non-Class 1E) portions of the Reactor
Control and Protection (RCP) instrument loops. The summator
modules are used to algebraically combine analog signals,
either adding or subtracting inputs in combination with module
gain and bias. The summators accept up to four inputs and
provide one summed and isolated output.
The reactor protection system is designed to assure that the
system can perform its required functions in the event of a
design basis earthquake. The defect could affect the modules'
ability to function during a design basis earthquake. It could
result in a loss of redundancy sufficient to constitute a major
degradation of essential safety related equipment. All
replacement modules for Salem Unit 2 have been inspected by the
vendor and repaired. All replacement modules for Salem Unit 1
have been returned to the vendor for inspection and repair.
PSE&G is investigating the cause of the defect with the vendor.
Results will be provided when the investigation is completed.
NOTIFICATIONS YES NO WILL BE ANYTHING UNUSUAL YES NO
OR NOT UNDERSTOOD? (Explain above)
NRC RESIDENT
STATE(s) (NJ)
(DEL) DID ALL SYSTEMS YES NO
FUNCTION AS (Explain
REQUIRED? above)
LOCAL (LACT)
OTHER GOV. MODE OF ESTIMATE FOR ADDITIONAL
AGENCIES OPERATION RESTART DATE: INFO ON
UNTIL PAGE 2?
MEDIA/PRESS CORRECTED:
RELEASE
ADDITIONAL INFORMATION FOR TELECOPY E
ECG Section Initiating Condition APPROVED FOR TRANSMITTAL:
SNSS
SGS Rev. 2
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