ML17252A292

Letter Submitting Reportable Occurrence Number 050-249/1977-17 in Accordance with Technical Specifications, Section 6.6.B

ML17252A292
Person / Time
Site:	Dresden
Issue date:	06/21/1977
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS77-543 050-249/1977-17
Download: ML17252A292 (3)

Text

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-t' Commonwealt.ison Dresden Nuclear Power Station R.R. #1

• Morris, Illinois 60450 Telephone 815/942-2920 Ltt~ II 77-543 June 21, 1977 BBS Mr. James G. Keppler, Regional Director

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Directorate of Regulatory Operations - Region III U. S. Nuclear Regulatory Commission 799 Roosevelt Road

• Glen Ellyn, Illinois 60137 Enclosedplease find Reportable Occurrence report number 50-249/1977-17.

This report is being submitted to your office in accordance with the Dresden Nuclear Power Station Technical Specifications, Sectibn 6.6.B.

- Q+/-l_1YJ~ .

~~.

r B. Stephenson

~tation Superint.endent .*

Dresden Nuclear Power Station

• BBS:sm

• Enclosure

.cc: Director of Inspection & Enforcement Director of Management Information & Program Control

File/NRC 77180005:::: JI

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CONTROL BLOCK: _l__.__.-lll l .- [P~E PRINT AU. REQU-IRED INFORMATIO *~ :.

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LICENSEE -LICENSE EVENT

- ,, _ , _ r'.IAME _ - - -: - - UCENSE NUMBER - _ - - TYPE - TYPE -

-@E] I I :1 L ID I RI s I 3 I I ol ol-1 ololol ol ol...;!o lo I 7 -8 9 14 15 - 25 l4 f1 11 I l I1I I 0 I 3 1.

26 30 31 32 REPORT REPORT CATEGORY -T'YPE- SOURCE DOCKET NUMBER _ -- EVENT CATE - . REPORT OATe

-1

@TI]toN* I - I I e 57 sa w w59 60 I ol sl ol-1oI21 4191 I oI sl 21 6 I 7 I 7 I 10 16 12 I 117 61 - 68 69 - 74 75 - -

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EVENT DESCRIPTION

--- @El I The Technical Specificatioru( state that an APRM _is considered -inoperable if it is 7 89:;--------~---~---=----~-____-:._~--~--~~--------__;,~-----------=-----~----...:...---~-

@El I receiving less that so% o"f its normal complement of i.PRM inputs. --During normal a~

7 -8 9 fo141 plant operation, APRM 114 was found to generate an i'INOP" when 60% of the LPRM inputs sf 7

lolslB 9I were -bypassed. Because- APRM 114 has 20 LPRM inputs, -the "INOP" should have been 60.

7 B 9 SG

@Th] ~I__.g...e;;.;n""e;;.;r;..;;a;;.;t;..;;e:;.;d;,_;,;w~h;..;;e;.;;;n~5.;;;5.;.;%__;;o~f__;;t.;.;h;.;;;e_;;;;L.;..P.;.;RM;.;;...;;;.in;;;;.pi;..u;;.t;:;..s::...._t;:;..o:.....;;AP~RM~-...;ll:...4;,_;,w..::e..::r..::e_:.b.:..yp.!:.::a..:.s.:.s.::.e.:.d.::.._.::.S.:..a_f.:.e.::.ty::.._i~*m_;p~l:.:i:.:*c:.:a::..t:_i_o::..:n::..:s_ _JI 7 8 9 PRME 80 SYSTEM -CAUSE - COMPONENT - COMPONENT ( * - -d)-

_tOOE COOE COMPONENT COOE SUPPUS'! MANuFACTlJS'Q - VIJl.AmN continue - -

@0 (1 IA 1* W I I IN I s I TI RI ul .l.JiJ *- - I GI o I 8 f o I UJ 1 as 10 11 12 11 43 - 44 47 49

. CAUSE DESCRIPTION-

-~ I The event- was attributed to- electronic -drift. The trip reference card for APRM 114 7 8 9 so

~ was adjusted to obtain the -"INOP" indication when the APRM was receiving less than.

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I 7 8 9 so

-El§] I -50% of its normal- complement of LPRM inputs. Although this type of failure has I

_1 - as METHOD OF (continued)SG FAc:uTY

. fiEl. w

- - STATUS

_ I ol 7f o J

"-POWER NA OTHER_ STATUS DISCOVERY LU NA DISCOVERY DESCRIPTION 1 a-rn w s

.FORM OF-ACTIVITY - - CONTENT RELEASED 10 OF RELEASE LzJ __

12' 13 AMOUNT OF ACTIVITY

, _____-_.-N""""A----~.;._j' 44

' 45 46 NA

' . - LOCATION OF RELEASE BO 1 a s

• 10 11 44 - 4~ BG

': ..: .. PERSONNEL EXPOSURES / .*

NUMBER - TYPE

[ill lo I ol ol LlJ 1 - es . 11 - i2 PERSONNEL INJURIES

- - -NUMBER . DESCRIPTION

[El I 0 I 0 I 0 I .';:;-~~N=A_ _ _ _ _ _ _ _ _ _ _ _ _ _ _.....;..._______________,

1 _ as 11 12_ 8C

- OFFSITE- CONSEQUENCES

-1 EEas NA Su J

LOSS OR DAMAGE TO FACILITY

- TYPE DESCRIPTION

-7

[!pJWes 10 PUBLICITY

.. [IT?] NA 7_ 8 9 AOOmONAL -FACTORS

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--- ~l~-----~----~-~---_.;.._____. .:. ____. . :. . ;.;_____.-~.I

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• 'EVENT' DESCRIPTION (Continued) of this event were minimal since the remaining two APRM instrument channels in the "B" Reac.tor Protection System would. have provided the required reactor scram.

(50-249/1971..;.17)

CAUSE DESCRIPTION (Continued) occurred before,* the APRM "INOP'.' points will continue .to lbe checked via DIS 700-6; a monthly surveillance, to ensure t{µieiy identification of a~y re~urring problem.

The.trip reference cards are General Electric type GE136Bl319Gl