ML19211C175
| ML19211C175 | |
| Person / Time | |
|---|---|
| Site: | Humboldt Bay, Diablo Canyon |
| Issue date: | 12/26/1979 |
| From: | Engelken R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| To: | Crane P PACIFIC GAS & ELECTRIC CO. |
| References | |
| NUDOCS 8001110028 | |
| Download: ML19211C175 (1) | |
Text
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o UNITED STATES e
NUCLEAR REGULATORY COMMISSION 7}
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REGION V 1
o, 1990 N. CAllFORNI A BOULEVARD SUITE 202 WALNUT CREEK PLAZA e..,e WALNUT CREE K, CALIFORNI A 94596 December 26, 1979 Docket flos. 50-133, 50-275, 50-323 Pacific Gas and Electric Company 77 Beale Street San Francisco, California 94106 Attention: Mr. Philip A. Crane, Jr.
Assistant General Counsel Gentlemen:
This Information flotice is provided as an early notification of a possibly significant matter.
It is expected that recipients will review the Information Notice for possible applicability to their facilities.
fio specific action or response is requested at this time.
However, we anticipate that further fiRC 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 f1RC Regional Office.
Sincerely, hN mcf]E R. H. Engelken Director
Enclosures:
1.
IE Information flotice flo. 79-33 2.
List of Recently Issued Information flotices cc w/ enclosures:
W. Barr, PG&E W. Raymond, PG&E R. Ramsay, PG&E, Diablo Canyon E. Weeks, PG&E, Humboldt Bay J. Worthington, PG&E 1737 335 8 0 0 1 1 1 o (J 2 P
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UNITED STATES SSINS NO.: 6870 NUCLEAR REGULATORY COMMISSION Accession t'o.:
0FFICE OF INSPECTION AND ENFORCEf1ENT WASHINGTON, D.C.
20555 7 91.0 250 626 December 21, 1979 IE Infomation flotice 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 fluclear 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 prinary containment equipment access hatches for Unit 2 was performed.
TVA reported on Decenber 20, 1979, to the NRC that t' ey had found six of twelve closing dogs on one hatch improperly n
aligned and ore closing bolt not torqued. A LLRT, performed with the hatch in this condition, showed a leakage rate higher than nomal 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 contain-ment 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 recomend or requast specific applicant or licensee actions.
This infomation 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 alignrent of the closing dogs. We expect that recipients will review the adequacy of their pro-cedures for access hatch installation at all facilities.
If installation pro-cedures 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 Infomation Notice is required.
1737 336
IE Information f!otice No. 79-33 Enclosure
- Decerder 21, 1979 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 79-32 Separation of Electrical 12/21/79 All power reactor facilitics Cables for HPCI and ADS holding OLs and cps 79-31 Use of Incorrect Amplified 12/13/79 All holders of power reactor Response Spectra (ARS)
OLs and cps 79-30 Reporting of Defects and 12/6/79 All power reactor facilities Nonconpliance,10 CFR Part 21.
holding OLs and cps and vendors inspected by LCVIP 79-29 Loss of NonSafety-Related 11/16/79 All power reactor facilities Reactor Coolant System holding OLs or cps Instrumentation During Operation 79-28 Overloading of Structural 11/16/79 All power reactor facilities Elements Due to Pipe Support with an OL or CP Loads 79-27 Steam Generator Tube 11/16/79 All power reactor facilities Ruptures At Two PWR holding OLs and cps Facilities79-12A Attempted Damage To New 11/9/79 All Fuel Facilities, Fuel Assemblies research reactors, and power reactors with an OL or CP 79-26 3 reach of Containment 11/5/79 All power reactor facilities Integrity holding Ols and cps 79-25 Reactor Trips At Turkey 10/1/79 All power facilities with Point Units 3 And 4 an OL or a CP 79-24 Overpressurization Of 10/1/79 All power reactor facilities Containrrent Of A PWR Plant with a CP After A Main Steam Line Break 1737 337