ML17252B570
| ML17252B570 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 07/28/1978 |
| From: | Stephenson B B Commonwealth Edison Co |
| To: | Keppler J G NRC/RGN-III |
| References | |
| BBS LTR 78-1099 LER 78-040/03L-0 | |
| Download: ML17252B570 (2) | |
Text
Dresden Nuclear Power Station R.R. #1 Morris, Illinois 60450 Telephone 815/942-2920 BBS LTR 1/78-1099 James* G, Keppler, -Regio-ri.al I>l.recfor July 28, 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 CJ (/) --t :::u OJ c::cC:::c:
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- 0 < ("') ,.,, (/') Director of Management Information
& Program Control File/NRC --:::i** en n"1 r:i r-1< G> A'rn 10: <o no rri-(J)(J) 2:! ' --t c:::t.J ::... :z--CD co -IC:: -I Cl 2'. l: "'-'
NRC FORMm-17-771 * -.* U.S. NU.CLEAR REGULATORY COMMISSION 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 I 0 7 8 9 LICENSEE CODE 14 15 LICENSE NUMBER 25 26 LICENSE TYPE JO 57 CAT 58 CON'T [iliJ 7 8 [ill] [[ill mIJ [I:]]] [ill] ITITJ L!J© I o I 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 'G) I o ! 8 I 1 I 8 I 7 I 8 10 60 61 DOCKET NUMBER 68 69 EVENT DATE i4 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES@ . I While performing APRM Setdown Functional Test (DIS 700-5), APRM Channel #4 Rod Block tripped at 12.5%, exceeding T.S. Sect 3.2 limit: APRM Rod Block </=12% of rated .pwr. Safety imp'lications minimal because 1 or more operable APRM' s per channel available as required by T.S.3,2 when APRM #4 was bypassed.
Similar event ref. in LER #78-029/03L-O, Docket 50-249. 7 8 9 80 CIT1] 7 8 SYSTEM CODE I II Al@ 9 10 /':":;\ LER/RO CVENT YEAR REPORT I 7 I 8 I NUMBER 21 22 CAUSE CAUSE COMP. CODE SUBCODE COMPONENT CODE SUBCOOE* _ L!j@. L!J@ II IN 1s IT IR 1u 11 -12 13 18 19 SEQUENTIAL OCCURRENCE REPORT REPORT NO. CODE TYPE I o I 4 I o I I ?I I o I 3 I W 23 24 26* 27 28 29 JO VALVE SUBCOOE 20 L=J 31 ACTION FUTURE EFFECT SHUTDOWN r:;::;., ATTACHMENT NPR0-4 PRIME COMP_ SUPPLIER REVISION NO. LQJ 32 COMPONENT MANUFACTURER TAKEN ACTION ON PLANT METHOD HOURS i.::51 SUBMITTED FORM :;us. w@LJ@ W@ . 'LJ Io Io Io I 01 LI!J@ 1.....!!J@
33 34 35 36 J 7 40 41 . 42 IG 10 18 10 I@ CAUSE DESCRIPTION AND CORRECTIVE ACTIONS @ 43 44 '\7 "[!]]] 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 FACILITY STATUS % POWER OTHER STATUS METHOD OF . r:;::;., 80 ITTIJ l.Ll@ a 9 ACTIVITY I 0 I 2 I 6 l@)l.___N_A
____ __, DISCOVERY DISCOVERY DESCRIPTION-
________ __, 7 10 CONTENT 12 11 44 RELEASED OF RELEASE AMOUNT OF ACTIVITY @ [QI) LlJ @)
______ ____, 7 8 9 10 11 44 PERSONNEL EXPOSURES 45 46 80 LOCATION OF RELEASE @ I NA, 45 80 NUMBER TYPE . G::E] I 01 ol
_____ NA __________________
__. 1 a 9 11 12 13 80 PERSONNEL INJURIES Q NUMBER
[i]Z] Io I o Io I@
- 1 a 9 11 LOSS OF OR DAMAGE TO FACILITY-143' TYPE DESCRIPTION
'::;:J ETIJ L2J@ -a 9 NA NA BO PUBLICITY
(.';\ ISSUEOQ NRC USE ONL y "' [IE)
_________
N_A __________
o--J II II II II II I I I 8 -9 10 68 69 80*;;;
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