Information Notice No. 84-37: Use of Lifted Leads and Jumpers During Maintenance or Surveillance Testing

                                                       SSINS No.:  6835 
                                                       IN 84-37 

                               UNITED STATES 
                           WASHINGTON, D.C. 20555 

                                May 10, 1984 

Information Notice No. 84-37:   USE OF LIFTED LEADS AND JUMPERS DURING 
                                   MAINTENANCE OR SURVEILLANCE TESTING 

All nuclear power plant facilities holding an operating license (OL) or a 
construction permit (CP). 


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

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 


                                                       IN 84-37 
                                                       May 10, 1984 
                                                       Page 2 of 3 

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 

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 

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, 

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. 

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 


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. 


                                                            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 

e.   Performing functional tests designed to verify the restoration of 
     proper system configuration following surveillance tests or 

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 

List of Recently Issued IE Information Notices

Page Last Reviewed/Updated Wednesday, March 24, 2021