ML19211C349
| ML19211C349 | |
| Person / Time | |
|---|---|
| Site: | Yankee Rowe |
| Issue date: | 12/21/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Groce R YANKEE ATOMIC ELECTRIC CO. |
| References | |
| NUDOCS 8001110229 | |
| Download: ML19211C349 (1) | |
Text
-73 pa ata,,q[o,,
UNITED STATES 4y )~
c'g NUCLEAR REGULATORY COMMISSION 3?
'E REGION I 0,
8 631 PARK AVENUE
% ' 'O p
KING oF PRUSSIA, PENNSYLVANIA 19406 Docket No. 50-29 21573 Yankee Atomic Electric Company ATTN:
Mr. Robert H. Groce Licensing Engineer 20 Turnpike Road Westborough, Massachusetts 01581 Gentlemen:
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 action.
If you have questions regarding this matter, please contact this office.
Sincerely,
/2D-
&'f
- s.,Boyce H. Grier w 0irector
./
Enclosures:
1.
IE Information Notice No. 79-33 2.
List of Recently Issued IE Information Notices CONTACT:
D. L. Caphton (215-337-5264) cc w/encls:
H. Autio, Plant Superintendent L. E. Minnick, President 1737 269 800111o 229
m
' g 3,o ENCLOSURE 1
,oj 2J UNITED STATES SSINS No.: 6870 NUCLEAR REGULATORY COMMISSION Accession No.:
79 jg 256524 0FFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D.C.
20555 IE Information Notice No. 79-33 Date:
December 21, 1979 Page 1 of 1 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 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 Regional Office.
No written response to this Information Notice is required.
1737 270
ENCLOSURE 2 IE Information Notice No. 79-33 Date:
December 21, 1979 Page 1 of 1 RECENTLY ISSUED IE INFORMATION NOTICES Information Subject Date Issued to Notice No.
Issued 79-24 Overpressurization of Con-10/1/79 All Power Reactor Faci-tainment of a PWR Plant lities with an Operating After a Main Steam Line License (OL) or Construction Break Permit (CP) 79-25 Reactor Trips at Turkey 10/1/79 All Power Reactor Faci-Point Unit 3 and 4 lities with an OL or CP 79-26 Breach of Containment 11/5/79 All Power Reactor Facil-Integrity ities with an OL or CP 79-12A Attempted Damage to New 11/9/79 All Fuel Facilities, Fuel Assemblies Research Reactors and Power Reactors with an OL or CP 79-27 Steam Generator Tube 11/16/79 All Power Reactor Faci-Ruptures at Two PWR lities with an OL or CP Facilities 79-28 Overloading of Structural 11/16/79 All Power Reactor Faci-Elements Due to Pipe Support lities with an OL or CP Loads 79-29 Loss of Nonsafety Related 11/19/79 All Power Reactor Faci-Reactor Coolant System In-lities with an OL or CP strumentation During Operation 79-30 Reporting of Defects and 12/6/79 All Power Reactor Faci-Noncompliances, 10 CFR lities with an OL Part 21 or CP 79-31 Use of Incorrect Amplified 12/13/79 All Power Reactor Faci-Response Spectra (ARS) lities with an OL or CP 79-32 Separation of Electrical 12/21/79 All Power Reactor Faci-Cables for HPCI and ADS lities with an OL or CP 1737 271