ML17252A288

Transmittal of Reportable Occurrence Report No. 50-249/1977-8

ML17252A288
Person / Time
Site:	Dresden
Issue date:	05/03/1977
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
50-249/1977-8
Download: ML17252A288 (3)

Text

Commonw. Edison Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920 BBS Ltr. # 77-393 May 3, 1977 REGULATORY DDCi[f fJlf_ ~0~

Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations - Region I I I U. S. Nuclear Regulatory Commission 799 Roosevelt Road G1en E11 yn, 111 i no is 6013 7 Enclosed please f i*nd Reportable Occurrence report number 50-249/1977-8.

This report is being submitted to your '8fifice in accordance with the Dresden

• Nuclear Power Station*Technical Specifications, Section 6.6.B.

tep enson Station Superintendent Dresden Nuclear Power Station BBS/iskm, Enclosure cc: Director of Inspection & Enforcement Director of Management Information &. Program Control

, Fi le,f;~RC r771~io147 MAY 5 1977 ------- l

L.* .us~ . PAINT ALL'REQUIAEd:INFO'RMATIO~J'

. .. ~

6

. I ... , .. - LICENSE NUMBER. .

LICENSE TYPE -

EVENT*

TYPE I o* o ,-.1 o I o I o I o I o 1-1 o I o I. l4 I 1 I 1 I 1 11 *f loJJ I 15  :- . . . ...* . c 25 26_ 30 31 32

. REPORT . REPORT

.CATEGORY TYPE. SOURCE . . OOCKET NUMBER . 'EVENT OA TE .

• REPORT CATE

@ill CON'T I I I lLJ LU lo Is Io 1-1 o 12 I 4 I 9. I I o *14 :1 6 lC# ltl I 74z I I *o I 5 I oI 3 I Z j 7~

7. . 8 ' 57 58 . 59 60 61 . 68 69 .. .75 .. * .. ed'.

EVENT OESCRiPTION

• • ~* _ Jol_2iJo'n Dresden Unit J, the output of'.LPRM 1.6-JJ.-D shifted upsc.ale, The LPRM was temporarily  !

.. lol31 I bypassed, -resulting i~ only one operable "D" level detector input @:IAPRM 3,. Since th~ ~

8 7 8 9 ..* ' .. *.*.. .*.* . . . j

.

• lal41 ;I Technical --Speci ficatrons reql!i re a minimum of t_wo .detector inputs per lev_el, APRM 3 wa.s BO

. fai~I>

7 .* 8 9 r su.bsequen t1 y by pa SSed; This event presents. no safety sign if i ca rice s fnce A'PRM., ~. iqJ;)i'(2 .so, 1

,.. (ojsj f were operable anc;lprovided the required inputs to the Reactor Protection System. This *.a~

7 8 9 . . PRME 80 SYSTEM CAUSE COMPONENT COMPONENT (continued)

. COOE CODE COMPONENT CODE SUPPUER MANUFACTURER

• [§0 .( I I B I LU . 11 IN Is IT I R I u , . ~ I GI 0 18 I 0 .I 7 8 9. 10 11. 12' 17> 43 44 .. 47

. (:

CAUSE DESCRIPTION * ' ., .

., *[ol 8 11T~e--upscale readJngof i..PRM l6-3Y*D w~s;:c;au~*ed by fa.ilure of the ceramic seal se~ara~lrlg I lalsl.9* th'~:*LPRM.~~~~ber*from- its'*~able::'P;Thjs typ~ of LPRM f~ilure, whi'c,h results i~*ari increa 7 gg . ..

• • -_ ~*I in detector se~sitivity, .has oc;urred at Dresden and other plants employing Generai 80

. 7 8 9 I

(continued) S!J

• • • .:* .. FACILITY METHOD OF

_:-~ .* (ill]

.. 7. 8

• STATUS 9LU... 10 POWER .

12 13

. . OTHER STATUS I 0 I 9 I 3 I ._..I....,...._.N_A_.....;..______,,

44'

. w DISCOVERY.

45 46.'

DISCOVERY DESCRIPTION* .

f Noted ab'nor'ma 11 y. high LPRM reading 80.

RJRM OF ACTIVITY . CONTENT RELEASED OF 'RELEASE ..* . AMOUNT OF..-ACTIVITY - LOCATION OF RE~SE

- [ill]

7**' 8

L2J 9 *.

• W 10 I

11 ..

NA* .. NA

. *.I 4~

• S'tl

..... ..* 'PERSONNEL '*EXPOSURES

• . .

• NUMBER *

• TYPE DESCRIPTION,: .. '*..

• * [!El J of ol DI .W NA**.*. ,*

1 *a.s ** 11 12 13 so.,*.

PERS'ONNEL INJURIES

• .. *... . NUMBER =:OESCRIPTION

. *. 7 (1J4l 8 9 ol o l.o 11I "-1';:;2- . *.......;....**NA

_ _._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.-;,__.;8\J OFFSITE CONSEQUENCES ' .

EE.e *~*s _-:--'""'NA-:-=-~-~*..._,...;..__ _ _..;.._""."'".*_*-~-":':"-;...____.___;.~..:...-:.,----_;._..;.._..;.._.,--_:..;..:__.:___..:...,---l

• .7

• au LOSS OR OAMAGE TO FACiLITY TYPE .OESCRIPTION

• 7EIDe. *s.LJJ

• NA ' . r,c_

1~0---~.....;.-......:;;~.;.;......---:---.-;..;.--,...,__~ .. -:..----....;....---....._..;.....__;.-;,....,;__ __;__ _ _ _ _ _ _ so*

PUBLICITY

.._[!£) NA 7 8 9 80 AOOmONAL FACTORS .

• .~

NA 7 8 9 80-

~ I.

-s~ffery

• • • ,.,..-----:-.--------.,..,,...---.....;....'----"---------------.....:...---w

_.,.__:.._..,~*'7--:----~rs~-=--------:-~-~-.o:-. ":"".":"",.,:-:--,'".:".:~--~::"'.-~***""-**""'*--""'.'.""'--*....

. R~*Woj_narowski ..* . (815) 942-2920 ext, 432

,,,,,., ..... NAM~=---~,.,._.,., __ ,..,_-""'***"'"'-""'---~..,,,,..._..---------- PHONE: ------*- r:.;.;;:_:>~_:

• ---~*-:*~.-..-*.-.,

I' .rr--, 1-41 A ,4J.l

""'* ._1*.1; 0

11, EVENT DESCRIPTION (continued) 'r'r*;~'..r~:*i-~*.i**::~.1

- - - - - - - - - - - _ - _ -....-...- - - - ' - .... :_. " ~* .; -*, ;*/1 is not a repetitive occurrence (50-249/1977-8).

~i!* 1 ij~ (ls. m!J ~ i -.:t CAUSE DESCRIPTION (continued)

Electrfc neutron flux detectors. At Dresden, comprehensive guidelines have b'een developed for the identification of LPRM abnormalities (including seal failures) and for immedffiate corrective action. Other procedures have been implemented which establish criteria for LPRM recalibration and for returning individual LPRM's to service.

After meeting procedural prerequisites, LPRM 16-33-D was returned to service on April 5, 1977, allowing APRM 3 to be returned to service. Continued use of these procedures and guidelines willDhelp maintain proper performance of the neutron monitoring system.