Information Notice No. 84-37: Use of Lifted Leads and Jumpers During Maintenance or Surveillance Testing
SSINS No.: 6835
IN 84-37
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
May 10, 1984
Information Notice No. 84-37: USE OF LIFTED LEADS AND JUMPERS DURING
MAINTENANCE OR SURVEILLANCE TESTING
Addressees:
All nuclear power plant facilities holding an operating license (OL) or a
construction permit (CP).
Purpose:
This information notice is provided to alert licensees and applicants of the
potential for significant degradation of safety associated with the use of
lifted leads or jumpers during either maintenance or surveillance testing.
This information is also provided to emphasize the value of independent re-
view of the use of lifted leads and jumpers. Recipients are expected to re-
view the information for applicability to their facilities and consider
actions, if appropriate, to preclude similar problems occurring at their
facilities. However, suggestions contained in this information notice do not
constitute NRC requirements and, therefore, no specific action or written
response is required.
Description of Circumstances:
Several instances of serious degradation of safety-related systems have
occurred in connection with the use of lifted leads or jumpers. Among the
most notable of these were the events at San Onofre Unit 3 and Sequoyah Unit
1.
At San Onofre Unit 3, on February 27, 1984, while performing a 31-day sur-
veillance test, the licensee discovered that four of eight reactor trip
breakers did not have their shunt trip devices operable because some leads
were not connected in the reactor protection system (RPS). As a result of an
investigation, the licensee attributed the cause to personnel failing to re-
connect leads that had been lifted during an 18-month surveillance test of
the reactor trip system that was conducted between January 26, 1984 and Feb-
ruary 16, 1984. The reactor had been shutdown since January 6, 1984.
A review of the instructions for the 18-month surveillance revealed that
there was no specific instruction that explicitly required reconnecting the
lifted leads. Instead, the instructions contained only a general directive
to return the system to its normal configuration at the completion of the
surveillance. In view of the length of time (several days) it took to com-
plete the entire surveillance, the fact that several people were involved,
and the vagueness and lack of procedural steps to reconnect specific lifted
leads, the surveillance instruction was inadequate to ensure restoration of
the proper system configuration. The procedural verification step lacked
independence and failed to
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IN 84-37
May 10, 1984
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discover the error of not reconnecting the lifted leads. Further, the 18-
month surveillance procedure did not include functional tests that would
have revealed the inoperable shunt trip device upon completion of the
procedure.
At Sequoyah Unit 1, on September 11, 1983, with the reactor shut down at 600
psig, both trains of the automatic actuation logic for reactor trip were
made inoperable when the undervoltage coils of the reactor trip breakers
were jumpered with the breakers closed and the control rods capable of
withdrawal. A procedural error in the manual reactor trip functional test
called for placing jumpers on the undervoltage coils and closing of the
reactor trip breakers thus defeating both trains of automatic reactor trip
logic.
In the past, there have been other instances, besides the two events already
discussed, of plant personnel defeating or degrading system functions as a
result of the inappropriate or careless use of lifted leads or jumpers,
including:
Date/ LER No. Plant System Defeated Cause
2-3-83 Calvert Cliffs Inverter for reactor Leads switched
007 protection system (blew during surveillance
fuse in inverter causing testing of inverter
plant transient)
7-14-83 LaSalle Unit 1 Emergency core cooling Leads switched,
073 system division 1 cause unknown
(initiation on -129 in.
level)
4-25-82 LaSalle Unit 1 Standby gas treatment 4 leads lifted to
017 system (suction valve wrong division of
would not open) system during sur-
veillance test
1-17-84 Millstone Unit 2 Two channels of thermal Leads from upper and
004 margin/low pressure trip lower ex-core
logic detection to logic
channels A & B of
RPS were reversed
Discussion:
The events described above emphasize the safety value of independent review
of the use of lifted leads and jumpers. NRC Regulatory Guide 1.118, Periodic
Testing of Electric Power and Protection Systems, also provides general
guidelines for good practice in the use of lifted leads and jumpers, and
Generic Letter 83-28 addresses the general topic of post maintenance
testing. Although it may not be possible to totally eliminate the use of
lifted leads and jumpers, initiating one or more of the following actions
would serve to reduce the likelihood of adverse effects on safety systems.
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IN 84-37
May 10, 1984
Page 3 of 3
a. Installing permanent test hardware for use in lieu of lifting leads and
installing jumpers, e.g., switches with either spring return from the
test position or control room indication while in the test position.
b. Including additional procedural checks on system configuration during
surveillance testing and maintenance, e.g., recording initial and final
positions of leads on equipment and/or adding precautionary statements
to procedures regarding effects of oversight.
c. Reviewing of procedures to ensure instructions for surveillance and
maintenance explicitly and unambiguously specify the reconnection of
any lifted leads and the removal of any jumpers.
d. Using at least two qualified operators to independently verify proper
system configuration before safety-related equipment is returned to
service.
e. Performing functional tests designed to verify the restoration of
proper system configuration following surveillance tests or
maintenance.
f. Reviewing with operators and maintenance personnel specific instances
of errors involving lifted leads or jumpers and the safety impact of
such errors.
No written response to this information notice is required. If you have any
questions regarding this matter, please contact the Regional Administrator
of the appropriate NRC Regional Office or this office.
Edward L. Jordan, Director
Division of Emergency Preparedness
and Engineering Response
Office of Inspection and Enforcement
Technical Contact: Eric W. Weiss, IE
(301) 492-4973
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