ML20028C816

Forwards LER 82-049/01T-0.Detailed Event Analysis Encl

ML20028C816
Person / Time
Site:	Millstone
Issue date:	01/05/1983
From:	Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	Haynes R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I)
Shared Package
ML20028C817	List: ML20028C816 ML20028C821
References
MP-4561, NUDOCS 8301140166
Download: ML20028C816 (3)

Text

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January 5,1983 MP-4561 Mr. Ponald C. Haynes Regional Administrator, Region 1 U. S. Nuclear Regulatory Ccunission Regional Office 631 Park Avenue King of Prussia, PA. 19406

Reference:

Facility Operating License No. DPR-65 Docket No. 50-336 Reportable Occurrence RO-50-336/82-49/1T-0

Dear Mr. Haynes:

This letter forwards the Li nsee Event Peport for Reportable Occurrence RO 82-49/1T-0. The incident was originally classified as a 30 day reportable.

Upon subsequent higher managanent review and re-evaluation, however, it has been detennined to reclassify the incident as prmpt reportable and subnit the Licensee Event Report pursuant to the requirements of Millstone Unit 2 Technical Specification 6.9.2.g. Three additional copies of oe report are enclosed.

Yours truly, NORTHEAST NUCLEAR ENERGY C04PANY

. J. Mroczka Station Superintendent Millstone Nuclear Power Station ATM/JGR:no

Attachment:

LER RO 82-49/1T-0 cc: Director, Office of Inspection and Enforcement, Washington, D. C. (30)

Director, Office of Managment Information and Program Control, Washington, D. C. (3)

U. S. Nuclear Regulatory Ccmnission, c/o Document Management Branch, Washington, D. C. 20555 l

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l 8301140166 830105 PDR ADOCK 05000336 O PDR .

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D03ET NtBEER 50-336;  ;

IDENTIFICM'Im & 00CURRENCE .

i Fire water storage tanks A and B levels were found to be below the miniman f required volumes of Technical Specification 3.7.9.1.b.

OCBOITIWS PRIN 'ID 00CURRENCE j

' Prior to occurrence the unit was operating at a steady state power level of 100 -i percent. .

DESCRIPTIN W 00CURRENCE l s  !

' On December 7,1982, at 0855, hours, while performing routine rounds, fire water _

- storage tank A and B levels were found:to be at 190,.153 gallons.and 190,074 i

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gallons respectively. 'Ihe , fire water storage: tanks were 4==arliately filled to above the required Technical Specification limit. Technical Specification 1 3.7.9.1.b requires two fire suppression water supplies, each with a minin-a  !

contained voltane of 200,000 gallons. [.

APPARENf CAUSE & 00CURRENCE Investigation revealed the A and B fire water make-up valve _ operators to be ,

inoperative. Disasesibly of 'A' make-up valve operator showed a stripped gear  ;!

caused by manual. operation of the valve without declutching the motor. 'B' motor operator was found to have a sticking brake. Additionally 'B' make-c) valve was .

binding.  ;

ANAINSIS T 00CURRENCE Operability of the fire suppression system ensures that adequate fire suppression-  ;

capability is available to confine and extinguish fires occurring in any portion  !

of the facility where safety related equipment is located._ '1he collective ca- -

.l pability of the fire suppression system is aclarante to minimize potential <1==<= i to safety related.equipnent. .;

' Assuming the worst single fire event, Millstone II main transformer, a 3900 gallon l per minute (gpn) water supply would be the maximan output with both fire water punps running. '1his provides anple water to extinguish the fire within 20 to 30 i minutes. Given a volane of 350,227 gallons -(190,074 + 190,153) taking suction at i 3900 gpn, a 97.5 minute supply of water would be available. Men operating with l l the Technical Specification requirement of 200,000 gallons, a 102.56 minute supply t

, of water would be available, a 5 minute difference. An additional 5 minute supply l

at that point would most likely have no significant inpact on the extinguislunent ,

of the fire.

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CORRBCTIVE ACTIN

'1he gear in 'A' make-up valve operator was rotated away frtmi the . stripped teeth and lubricated. . '1he sticking brake. in 'B'. make-up valve operator.was removed and the valve lubricated.

'1he preventive maintenance frequency on both valves was increased in order to reduce the number of failures. Additionally, an engineering work request was generated to look into the feasibility of changing the operators.

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