Home > NRC Library > Document Collections > Generic Communications > Information Notices > 1983 > IN 83-53
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 8308040023 . 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 Attachment: List of Recently Issued IE Information Notices .
Page Last Reviewed/Updated Friday, May 22, 2015