Protecting People and the EnvironmentUNITED STATES NUCLEAR REGULATORY COMMISSION
SSINS No.: 6835
IN 83-27
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
May 4, 1983
Information Notice No. 83-27: OPERATIONAL RESPONSE TO EVENTS CONCERNING
DELIBERATE ACTS DIRECTED AGAINST PLANT
EQUIPMENT
Addressees:
All nuclear reactor facilities holding an operating license (OL) or
construction permit (CP).
Purpose:
This information notice is provided as a notification of events which may
have involved deliberate acts directed against plant equipment and a lack of
station procedures concerning response by operating personnel. It is
expected that recipients will review the information for applicability to
their station procedures. No specific action or response is required at this
time.
Description of Circumstances:
A review of recent operating reactor events indicates that some improper
valve positioning and instrumentation irregularities may have involved
deliberate acts directed against plant equipment in vital areas. The
following is a brief account of these events.
At the first facility, during routine operation, the Control Room Operator
received a steam generator feedwater pump (SGFP) high vibration alarm.
Subsequently the SGFP tripped and the operator immediately reduced turbine
load to prevent the unit from tripping. The instrument valves on the low
vacuum trip sensing line located outside vital areas were apparently
deliberately repositioned resulting in the pump trip. The licensee concluded
that this deliberate act could have been a result of a labor dispute.
At the second facility, during a routine operator tour at approximately 1:00
a.m., a manual valve was found shut in the common suction piping to the high
head safety injection (HHSI) pumps. The valve was immediately reopened. This
valve, which is checked by operators each shift, had been verified open at
about 4:30 p.m. the previous day. The chain and padlock which secured this
valve in the open position were missing. Additionally, on the previous day
the manual suction isolation valves of the three auxiliary feed-water pumps
had been found unchained and unlocked in violation of technical
specifications requirements. These valves were found in their normally open
position. The motive behind the actions was not proven, but the actions
resulted in the HHSI system being inoperable.
8303040030
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IN 83-27
May 4, 1983
Page 2 of 2
These events, and events at other plants, demonstrate that the potential for
deliberate acts directed against plant equipment must be recognized. In the
two above events the licensees were not totally prepared for operational
followup actions. Other licensees may or may not be prepared to assess the
situation and take necessary steps to assure operability of systems
important to safety or make decisions concerning continued operation.
Guidelines or procedures prepared by the licensee outlining a process for
followup of both deliberate and inadvertent acts with respect to plant
operation should be available.
The guidelines and procedures should include a verification of the affected
system(s) alignment, the system(s) control logic, and the availability of
the system(s) main power supply. In addition interrelated systems should be
inspected and selected safety-related electrical panels and cabinets, both
in the plant and in the control room, may require a detailed inspection. If
additional tampering is detected, the licensee should be prepared to make a
decision on whether or not continued operation is justified and whether or
not systems necessary for a safe shutdown are operable.
Operational and security procedures to cope with radiological sabotage and
other threats to safety must be developed in accordance with 10 CFR
73.55(h)(1) and Appendix C of Part 73. The potential impact of any
deliberate act directed against plant equipment must be evaluated, and
actions taken to mitigate the anticipated safety consequences.
No written response to this 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: Paul R. Farron, IE
(301) 492-4766
Attachment:
List of Recently Issued IE Information Notices
.
