ML17252A292
| 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 BBS Ltt~ II 77-543 Mr. James G. Keppler, Regional Director Directorate of Regulatory Operations - Region U. S. Nuclear Regulatory Commission 799 Roosevelt Road June 21, 1977
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- 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.
- BBS:sm
- Enclosure
.cc: Director of Inspection & Enforcement
- Q+/-l_1YJ~.
- ~~. B. Stephenson r ~tation Superint.endent Dresden Nuclear Power Station Director of Management Information & Program Control
- File/NRC I
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--- @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
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lolsl I were -bypassed.
Because-APRM 114 has 20 LPRM inputs, -the "INOP" should have been 7
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-~ I The event-was attributed to-electronic -drift.
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was adjusted to obtain the -"INOP" indication when the APRM was receiving less than.
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-El§] I -50% of its normal-complement of LPRM inputs.
Although this type of failure has so I
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_1 - as FAc:uTY
- - STATUS METHOD OF DISCOVERY (continued)SG
"-POWER DISCOVERY DESCRIPTION
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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