05000245/LER-1982-006, Forwards LER 82-006/03L-0.Detailed Event Analysis Encl

Forwards LER 82-006/03L-0.Detailed Event Analysis Encl

ML20042B299
Person / Time
Site:	Millstone
Issue date:	03/15/1982
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO.
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20042B300	List: 05000245/LER-1982-006, Forwards LER 82-006/03L-0.Detailed Event Analysis Encl 05000245/LER-1982-006-03, Le 82-006/03L-0:on 820212,MSIV 1-MS-2C Closing Time Exceeded Tech Spec Range.Caused by Maladjustment of Control Valve Hydraulic Cylinder.Cylinder Speed Readjusted
References
MP-1-2029, NUDOCS 8203250196
Download: ML20042B299 (2)

LER-1982-006, Forwards LER 82-006/03L-0.Detailed Event Analysis Encl

Event date:
Report date:
2451982006R00 - NRC Website

text

{{#Wiki_filter:- t NORTHI!AST trrII.rFII!S 5 %:%"'C",CTCTT~ OfnErdnE CONNECTICUT 06101 !!!'0 'CZ'ZT"~ (2MN6911 1 L L J =;=12=ll,71rl l March 15, 1982 MP-1-2029 Mr. Ronald C. Haynes I Regional Administrator, Region I \\6i's Office of Inspection and Enforcement C. U.S. Nuclear Regulatory Commission sy 'U' 631 Park Avenue f/ p ~^- 7 7.. ' 9 King of Prussia, Pennsylvania 19406 w D;hs '.. ,..,i ;- a. -{ n: ^l, k

Reference:

Provisional License DPR-21 "! 'd /J Docket No. 50-245 Reportable Occurrence R0-82-6/3L Vs /C

Dear Mr. Haynes:

~ This letter forwards the Licensee Event Report for Reportable Occurrence R0-82-6/3L required to be submitted within 30 days pursuant to the requirements of the Millstone Unit 1 Technical Specifications, Section 6.9.1.9.a. An additional three copies of the report are enclosed. Yours truly, NORTHEAST NUCLEAR ENERGY COMPA Y APT A/ E J. Mroczka l Station Superintendent Millstone Nuclear Power Station l EJM/TST:mo

Attachment:

LER R0-82-6/3L l l cc: Director, Office of Inspection and Enforcement, Washington, D.C. (30) l Director, Office of Management Information and Program Control, Washington,D.C.(3) U.S. Nuclear Regulatory Commission, c/o Document Management Branch, Washington, D.C. 20555 l l l 8203250196 820315 PDR ADOCK 05000245 8 hsh S PDR

l ATTACHMENT TO LER 82-6/3L NORTHEAST NUCLEAR ENERGY COMPANY MILLSTONE NUCLEAR POWER STATION - UNIT 1 PROVISIONAL LICENSE NUMBER DPR-21 DOCKET NUMBER 50-245 Identification of Occurrence Operation in a degraded mode permitted by a limiting condition for operation occurred when a main steam isolation valve failed to meet Technical Specification's closure time. Conditions Prior to Occurrence Prior to occurrence the unit was in the refuel mode with reactor pressure at 350 psig. Description of Occurrence On February 12,1982, at 1250 hours, while performing Main Steam Isolation Valve Closure Functional Test, main steam isolation valve 1-MS-2C closing time was found to be 5.2 seconds. _ Technical Specification, Table 3.7.1. requires all main steam isolation valves to close within 3 to 5 seconds of a primary contairiment isolation signal. 1-MS-lC, upstream main steam isolation valve was closed to allow investigation of 1-MS-2C. Apparent Cause of Occurrence Investigation revealed the control valve hydraulic cylinder to be slightly out of adjustment. Analysis of Occurrence Four main steam lines comprise a portion of the reactor coolant system. Their failure could result in uncovering the reactor core and therefore are supplied with automatic isolation valves. Analysis indicate fuel rod perforation would be avoided for a main steam isolation valve (MSIV) closure time of 10.5 seconds, For added margin Technical Specifications requires a MSIV closure time of not greater than 5 seconds. Therefore, a MSIV closure time of 5.2 seconds would have adequately prevented uncovering the core and subsequent fuel rod damage. Corrective-Action The control valve hydraulic cylinder speed was readjusted to obtain a main steam isolation valve closing time within its acceptable Technical Specification range. }}