ML19211C170
| ML19211C170 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 12/21/1979 |
| From: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | Millen C PUBLIC SERVICE CO. OF COLORADO |
| References | |
| NUDOCS 8001110021 | |
| Download: ML19211C170 (1) | |
Text
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CENTRAL FILES n afc UNITED STATES
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- NUCLEAR REGULATORY COMMISSION PDR:HQ REGION Iv LPDR
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% W,. f,f s, v Dece=ber 21, 1979 iocket No. 50-267 Public Service Company of Colorado ATTN:
Mr. C. K. Millen Senior Vice President Post Office Box 840 Denver, Colorado 80201 Gentlemen:
This IE 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 ti=e.
However, we anticipate that further NRC evaluations will result in issuance of an IE Circular or Bulletin in the near future which will reco==end or request specific applicant or licensee actions.
If you have questions regarding the =atter, please contact the Director of the appropriate NRC Regional Office.
Sincerely, l
- F[
r1 V. Seyfri.
Director
Enclosures:
1.
IE Infor=ation Notice No. 79-33 2.
List of Recently Issued Information Notices cc:
D. W. Warembourg, Nuclear Production
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737 329 Fort St. Vrain Nuclear Station P. O. Box 368 Platteville, Colorado 80651 L. Brey, Manager, Quality Assurance 8001119 h2/
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UNITED STATES SSINS NO.:
6870 NUCLEAR REGULATORY COMMISSION Accession No.:
OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 791025o 5 2 o December 21, 1979 IE 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 refue19ng 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 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 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 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 Regiona] Office.
No written response to this Information Notice is required.
1737 330
IE Information Notice No. 79-33 December 21, 1979 LISTING OF RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued To Notice No.
Issued 79-27 Steam Generator Tube 11/16/79 All power reactor facilities Ruptures at Two PWR holding Operating Licenses Facilities (OLs) and Construction Permits (cps) 79-28 Overloading of Structural 11/16/79 All power reactor facilities Elements Due to Pipe Support with an Operating License (OL) or Construction Permit (CP) 79-29 Loss of NonSafety-Related 11/16/79 All power reactor facilitier Reacter Coolant System holding Operating Licenses Instrumentation During (OLs) or Construction Operating Permits (cps) 79-30 Reporting of Defects and 12/6/79 All power reactor Noncompliance, 10 CFR facilities holding Part 21.
Operating Licenses (OLs) and Construction Permits (cps) and vendors inspectors inspected by LCVIP 79-31 Use of Incorrect Amplified 12/13/79 All power reactor Response Spectra (ARS) facilities holding Operating Licenses (OLs) and Construction Permits (cps) 79-32 Separation of Electrical 12/21/79 All power reactor Cables for HPCI and ADS facilities holding Operating Licenses (OL) and Construction Permits (cps)
Enclosure 1737 331
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