Information Notice No. 83-53: Primary Containment Isolation Valve Discrepancies
SSINS No.: 6835
IN 83-53
UNITED STATES
NUCLEAR REGULATORY COMMISSION
OFFICE OF INSPECTION AND ENFORCEMENT
WASHINGTON, D.C. 20555
August 11, 1983
Information Notice No. 83-53: PRIMARY CONTAINMENT ISOLATION VALVE
DISCREPANCIES
Addressees:
All boiling water reactors holding an operating license (OL) or construction
permit (CP).
Purpose:
This information notice is provided as a notification of discrepancies in
the initiating signals for group 1 primary containment isolation valves. It
is expected that recipients will review the information for applicability to
their station. No specific response is required at this time.
Description of Circumstances:
On January 3, 1983, at Browns Ferry Station, the site resident inspector
reviewed technical specifications section 3.7. During the review the
resident inspector noted that the isolation valves in the reactor water
sample line were listed as group 1 isolation valves, and these valves
receive a close signal from all the group 1 initiating signals. The FSAR
also stated that all group 1 initiating signals will shut these sample
valves. These findings appeared to conflict with the actual logic and an
examination of the electrical diagrams indicated that the sample valves only
close from two of the five group 1 isolation signals. Those two signals are
low low reactor water level (level 2) and high main steam line radiation.
This was verified to be consistent with the actual circuitry. The resident
inspector reported the discrepancy to the Regional Office and the Office of
Inspection and Enforcement for followup actions.
During the summer of 1982 the technical specifications surveillance
requirements were reviewed at Brunswick Station. The listed group 1
isolation valves were compared with the valves that actually isolate from
each group 1 isolation signal. The reactor sample valves were listed as
isolating on all group 1 isolation signals when they actually close on only
two signals (low low reactor water level and high main steam line
radiation). Following the identification of the discrepancy, Brunswick
Station personnel contacted General Electric to verify the adequacy of the
actual design.
A review of other BWR/4 technical specifications and discussions with
General Electric indicate that this discrepancy between the listed technical
specification isolation signals and the actual signals may be widespread. It
appears that at some point in the evolution of BWRs the initiating signals
for the
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IN 83-53
August 11, 1983
Page 2 of 2
group 1 isolation valves were separated but the change was not reflected in
the technical specification. This separation has been included in the
technical specifications of newly licensed plants.
Following the discovery of the discrepancy in isolation signals at Browns
Ferry Station the licensee has amended the technical specifications for Unit
2 to reflect the actual logic and expects to amend the technical
specifications for Units 1 and 3. The personnel at Brunswick Station also
plan to apply for a change to their technical specification to reflect the
actual logic. It may be prudent for other BWR owners to compare their listed
technical specifications isolation signals against the actual logic.
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
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