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Information Notice No.: 79-33- Improper Closure of Primary Containment Access Hatches
IN79033 December 21, 1979 MEMORANDUM FOR: B. H. Grier, Director, Region I J. P. O'Reilly, Director, Region II J. G. Keppler, Director, Region III K. V. Seyfrit, Director, Region IV R. H. Engelken, Director, Region V FROM: Norman C. Moseley, Director, Division of Reactor Operations Inspection, Office of Inspection and Enforcement SUBJECT: Information Notice No. NO.: 79-33- IMPROPER CLOSURE OF PRIMARY CONTAINMENT ACCESS HATCHES The subject document is transmitted for issuance on December 21, 1979. The Information Notice should be issued to all power reactor facilities holding operating licenses and construction permits. Also enclosed is a draft copy of the transmittal letter. Norman C. Moseley, Director Division of Reactor Operations Inspection Office of Inspection and Enforcement Enclosures: 1. Draft Transmittal Letter 2. IE Information Notice No. 79-33 CONTACT: W. R. Mills, IE 49-28180 . (Transmittal letter for Information Notice No. 79-33 to each holder of an NRC Operating License and Construction Permit.) Information Notice No. 79-33 This Information Notice is provided as an early notification of a possibly significant matter. It is expected that recipients will review the Information for possible applicability to their facilities. No specific action or response is requested at this time. However, we anticipate that further NRC evaluations will result in issuance of an IE Circular or Bulletin in the near future which will recommend or request specific applicant or licensee actions. If you have questions regarding the matter, please contact the Director of the appropriate NRC Regional Office. Sincerely, (Signature) (Regional Director) Enclosure: 1. IE Information Notice No. 79-33 2. List of Recently Issued Information Notices . UNITED STATES SSINS No.: 6870 NUCLEAR REGULATORY COMMISSION Accession No: OFFICE OF INSPECTION AND ENFORCEMENT 7910250520 WASHINGTON, D.C. 20555 December 21, 1979 Information Notice No. 79-33 IMPROPER CLOSURE OF PRIMARY CONTAINMENT EQUIPMENT ACCESS HATCHES Description of Circumstances: On December 8, 1979 difficulty was experienced in establishing the required nitrogen pressure in primary containment during power range startup testing of the Browns Ferry Nuclear Plant, Unit 3, following a refueling outage. On December 9, 1979, the licensee found three loose bolts on an equipment hatch to be the cause of leakage from the primary containment. The leakage was calculated to have been ten times the allowable containment leakage rate. This hatch had previously passed a local leak rate test (LLRT) and an integrated leak rate test of the containment in November 1979. The reactor had returned to operation on December 6, 1979 from the refueling outage and had operated at power levels less than 25 percent since December 6, 1979. A subsequent inspection by the licensee of both primary containment equipment access hatches for Unit 2 was performed. TVA reported on December 20, 1979, to the NRC that they had found six of twelve closing dogs on one hatch improperly aligned and one closing bolt not torqued. A LLRT, performed with the hatch in this condition, showed a leakage rate higher than normal but within Technical Specification limits. The second hatch on this unit was found to have eight of twelve closing dogs improperly aligned. The licensee is in the process of inspecting the closure of both primary containment equipment access hatches on Unit 1 and is reinspecting these hatches on Unit 3. It is anticipated that further NRC evaluation will result in issuance of an IE Circular or Bulletin in the near future which will recommend or request specific applicant or licensee actions. This information is provided to inform licensees of a possibly significant matter. The improper closure of the primary containment access hatches resulted from a lack of procedures for torque values, sequence of torque, and alignment of the closing dogs. We expect that recipients will review the adequacy of their procedures for access hatch installation at all facilities. If installation procedures do not exist or are inadequate, inspection and local leak rate testing can be used to confirm containment penetration integrity. If you have any questions regarding this matter, please contact the Director of the appropriate NRC Regional Office. No written response to this Information Notice is required.
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