ML17252B570

LER 78-040/03L-0 for Dresden, Unit 2 Re APRM Channel #4 Rod Block Tripped at 12.5%, Exceeding T.S. Sect 3.2 Limit

ML17252B570
Person / Time
Site:	Dresden
Issue date:	07/28/1978
From:	Stephenson B Commonwealth Edison Co
To:	James Keppler NRC/RGN-III
References
BBS LTR 78-1099 LER 78-040/03L-0
Download: ML17252B570 (2)

Text

Common~e.Edison Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920

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James* G, Keppler, -Regio-ri.al I>l.recfor Directorate of Regulatory Operations - Region III U,S, Nuclear Regulatory Commission 799 Roosevelt Road Glen Ellyn, IL 60137 BBS/def>

Enclosure*

cc: Director of Inspection & Enforcement Director of Management Information & Program Control File/NRC

NRC FORMm- - . U.S.

• NU.CLEAR REGULATORY COMMISSION 17-771 LICENSEE EVENT REPORT

• CONTROL BLOCK:  !-I-~___.__ _.___..l_ _.l.__-:!10 (PLEASE PRINT OR TYPE All REQUIRED INFORMATION) 1 6

[ij}] I I I LI D I R I s I 2 101 0 I 0 I - I 0 I 0 I 0 I 0 I 0 I - I 0 I 0 101 4 I 1 I 1 I 1 I 1 101 I I0 7 8 9 LICENSEE CODE 14 15 LICENSE NUMBER 25 26 LICENSE TYPE JO 57 CAT 58 CON'T

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~~~~~ L!J© I oI 5 I o I o I o I 2 I 3 I 7 101 o I 6 I 2 I 6 I 7 I 8 60 61 DOCKET NUMBER 68 69 EVENT DATE i4

'G) I o ! 8 I 1 I 8 I 7 I 8 10 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES@ .

I While performing APRM Setdown Functional Test (DIS 700-5), APRM Channel #4 Rod Block

[ill] tripped at 12.5%, exceeding T.S. Sect 3.2 limit: APRM Rod Block </=12% of rated

[[ill .pwr. Safety imp'lications minimal because 1 or more operable APRM' s per channel mIJ r~mained available as required by T.S.3,2 when APRM #4 was bypassed. Similar

[I:]]] event ref. in LER #78-029/03L-O, Docket 50-249.

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ITITJ 7 8 9 80 SYSTEM CAUSE CAUSE COMP. VALVE CODE CODE SUBCODE COMPONENT CODE SUBCOOE* _ SUBCOOE CIT1] I II Al@ L!j@. L!J@ II IN 1s IT IR 1u I~ ~ ~@

7 8 9 10 11 - 12 13 18 19 20 SEQUENTIAL OCCURRENCE REPORT REVISION

/':":;\ LER/RO CVENT YEAR REPORT NO. CODE TYPE NO.

~ REPORT NUMBER I7 I8 I Io I4 Io I I?I I oI 3 I W L=J LQJ 21 22 23 24 26* 27 28 29 JO 31 32 ACTION FUTURE EFFECT SHUTDOWN r:;::;., ATTACHMENT NPR0-4 PRIME COMP_ COMPONENT TAKEN ACTION ON PLANT METHOD HOURS i.::51 SUBMITTED FORM :;us. SUPPLIER MANUFACTURER w@LJ@

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43 44 '\7 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS @

"[!]]] I Cause attributable to setpoint drift of R-25 on module board Z34. Upon* discovery, APRM #4 placed in /"Bypass". DIS 700-5 was performed and APRM 114 Rod Block Setdown Reference promptly reset to 11,5% (Dresden setpoint is ll,5+A. ~%), The APRM Scram

[JJ]J I Rod Block Setdown Functional Tests will continue to be completed as required and

~ I during refueling outages.

1 a 9 80 FACILITY METHOD OF . r:;::;.,

STATUS  % POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION- ~

ITTIJa l.Ll@ I 0 I 2 I 6 l@)l.___N_A_ _ _ ___, L!J~l~--S_u_r_v_e_i_l_l_a_n_c_e_T_e_s_t_i_n~g_ _ _ _ _ _ _ ___,

7 9 10 12 11 44 45 46 80 ACTIVITY CONTENT RELEASED OF RELEASE AMOUNT OF ACTIVITY @ LOCATION OF RELEASE @

[QI) LlJ @) W@l~_NA_ _ _ _ _ _____, NA, I 7 8 9 10 11 44 45 80 PERSONNEL EXPOSURES ~

NUMBER TYPE DESCRIPTION~ .

G::E] I 01 ol oj@UJ@~_____ NA_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___.

1 a 9 11 12 13 80 PERSONNEL INJURIES Q NUMBER DESCRIPTION~

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1 a 9 Io I o Io 11I@

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~12-----------------------.,---------~-------'so LOSS OF OR DAMAGE TO FACILITY-143' TYPE DESCRIPTION '::;:J ETIJa L2J@

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NA BO PUBLICITY (.';\

ISSUEOQ DESCRIPTION~ NRC USE ONL y "'

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