ML20037B625
| ML20037B625 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 09/29/1980 |
| From: | Ullrich W PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 2-80-20, NUDOCS 8010270124 | |
| Download: ML20037B625 (2) | |
Text
{{#Wiki_filter:.w. -.~.Q j%% PHILADSLPMIA CLECTRIC COMPME 8 Peach Settea Atomis Power Statien J.4ML-l Delta, Psassylvania '_"'{ g; 17314 r -+ ^' T _ September 1; a m.a g e.
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% g. .i Mr. Boyce M. Grier a 4 j ~ .,JE,D.. e_.,D&,,,;.,... Office of Inspection and Enforcement gg%,,b,, 3. Region 1 - M y@. United States Nuclear Regulatory Commission c;-
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SUBJECT:
REPORTABLE OCCURRENCE - PROMPT NOTIFICATION e Confirming Steve Roberts' conversation with Mr. Cougill{en} f h.~ Septenhor 26, 1980.
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..a ..r;,...x. :n Refersace: Docket No. 50-277 ~ O l=.:. gj g.. .M.5. % Peach Botton Unit 2 (([Q.M ; Technical Specificaties
Reference:
3.4.3.1 r.5p.. y.6 Report No. 2 80-20/17 . ;;W i.~' '.-
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Occurrence Datt: September 26, 1980 pp- .a. ~..?' .c. e. s Ide:stification of Occurrence: p, e;; with the unit operating at 99% power, ammuncir. dor "SSLC Ross. of',,'j.S continuity" alarmed, alerting the operator to a ponable failure "~, or firing of the '5' standby liquid control squib valve. The ' 2 2.A explosive valve is continuously monitored by a light. sensitive s. A loss 2 met u circuit in series with the squib firing mechantaa. firing of a squib valve will*[p, of continuity in the circuit or the alarm the continuity alarm. 3.. ee-The valve firing and monitoring circuitry is fed from a 480 V/120'Y step down transformer in the pump breaker compartment. Investigatie following the alarm found the breaker (52-3723) to be open. The feed was immediately restored. The NRC resident inspector was notified of the situation. Continued operation was permissible under technical specification limiting condition for operation 3.4.3.1. Due to the system being quickly returned to service, ao testing on the 'A' SKLC paup was performed. Condit 3ns Prior to 00currence' Unit 2 operating at essentially full power. Both SELC pumps and ' injection valves. operable. 8010270/;2f J
2-Apparent Cause of Occurrence: The breaker is located adjacent to a " step-off pad" at approximately k2ee level. It -is believed the breaker was tripped accidencly by bumping isto the thew switch while entering or exiting the area. Analysis of Occurrence: The sBLC systec is designed to be used as a redundant and independent system to hitz the reactor from full power to a cold. xenon free chstdown in the event of control rod failure to insert. The oystem is manually initiated from the control room through a three pssition key switah. Had initiation been required, the operator would have observed the failure of the 'B' pump to start and no flow. No would them be able to'tura the switch to start the 'A' pump. Upon actuation of the switch both valves are designed to fire. However, only the 'A' would have opened under these conditions. Since the 33LC is designed to be able to provide the begon solution eith only one pumping system available, the loss of one pump had minimal safety significance as described in technical specification 3.4 bases. Corrective Action: After the breaker was restored satisfactory o eration was ~verif'ied" b y cammally cycling ~ the breakez~open a'ad ~cl ~ s e'd.p' To pre'ciude further inadvertent operation, the breaker switca was locked in the 'Ok' -position. The s' top-off pad in this vicinity is also being relocated. P-evious Failures: None similar. 2-e. I. Very truly yours, JA~ .T N NH _4 p ,~ N W. 7. Ullrich Si Station Superintendent 3 %%"p $$N S$.$
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