05000280/LER-2076-011, Re Deviation of Nuclear Instrumentation System Power Range Channel N42
| ML19105A152 | |
| Person / Time | |
|---|---|
| Site: | Surry  |
| Issue date: | 07/21/1976 |
| From: | Stallings C Virginia Electric & Power Co (VEPCO) |
| To: | Moseley N NRC/RGN-II |
| References | |
| Serial No. 150 LER 1976-011-00 | |
| Download: ML19105A152 (3) | |
| Event date: | |
|---|---|
| Report date: | |
| 2802076011R00 - NRC Website | |
text
e VIRGINIA. ELECTRIC A.ND POWER COMPANY R10HMOND,VIRGINIA. 23261 July. 21, 1976, Mr~ Nonnan c. Moseley, Director Directorate of Regulatory Operations United States Atomic Energy Commission Region II - Suite 818 230 Peachtree Street, Northwest Atlanta, Georgia 30303
Dear Mr. Moseley:
Serial No. 150 PO&M/WC: j 1f Docket No.
50-281 License No. DPR-37 Pursuant to Surry Power Station Technical Specification 6.6.B.2, the Virginia Electric and Power Company hereby submits a copy of Licensee Event Report No. USRE-S2-76-11.
The substance of this report has been reviewed by the Station Nuclear Safety and Operating Committee and will be placed on the agenda for the next meeting of the System Nuclear Safety and Operating Committee.
Very truly yours,
~~
c. M. Stallings
~
Vice President-Power Supply and Production Operations Enclosure cc:
Mr. Robert w. Reid, Chief (40 copies)
Operating Reactors Branch 4
" C
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'CENSEE EVENT CONTROL BLOCK :l.... ___.____.I_._I _ _._I __.._I ___.I REPORT e LIC5NSEE.
NAME
@El IV I A Is I p I s I 21 7
8 9 14 CATEGORY REPORT TYPE 1
6 LICENSE NUMBER I o I o l - I o I o I o I o I o 1 -1 9l_QJ 15 25 REPORT SOURCE DOCKET NUMBER [PLEASE PRINT ALL REQUIRED INFORMATION)
LICENSE TYPE I 4 I 1 I 1 I 1 1
- o I 26 30 EVENT DATE EVENT TYPE I o I 3 J 31 32 REPORT DATE
@BcoN'T I Ml II LU w 10 I 5 I o I - I o 1 2 I 8 I 1 I IOl6l21617161 I o I z I 1 lg I z I 6 I 7
- 8.
57 58 59 60 61 68 69 74 75 80
EVENT DESCRIPTION
@lg] I During a normal operating shift it was found that the Nuclear Instrumentatioi1 System I
7 8 9
@@I I (NIS) Power Range Channel N42 deviated from channels N41,N43, and 80 N44 by 3% in the non-!
7
. 8 9 BO lol4! I conservative direction. Ibis ca11sed the channel to be 7
8 9 Jaw by 3%, thereby req1dri.ng a I 80
@:@] jflux of 110% to cause a trip on this channel.
This is contrary to Technical Specific~
7 8 9
- 80
@:l§J ltion 2.3 which requires 7
8 9 a setpoint of 109% and is reportable per T.S.6.6.2b(2),
j, SYSTEM CODE
@El !z tz I 7
8 9 10
CAUSE
CODE UJ 11 CAUSE DESCRIPTION COMPONENT CODE LI I NI s IT I RI u I 12 17 PRIME COMPONENT SUPPLIER
~
43 COMPONENT MANUFACTURER I w 11 12 Io I 44 47
. (USRE-S2-76-ll) so '
VIOLATION L1LJ 48
~
!The immediate corrective action taken was to place Channel N42 in the trip mode. The I
7 8 9 80
@1fil I unit continued *to operate on the remaining three power range channels.
The accuracy I
7 8 9 80 f1fo1 iof_these channels had been checked against a heat balance at the beginnina of the shift!.
7 8 s
{Con* t )SD METHOD OF FACILITY STATUS
% POWER OTHER STATUS DISCOVERY DISCOVERY DESCRIPTION
~ w Ii Io 1 o I I N/A LsJ I
J NIA 7
8 9
10 12 13 44 45 46 BO FORM OF ACTIVITY CONTENT N/A RELEASED OF RELEASE AMOUNT OF ACTIVITY rn w Lu I N/A LDCA TJON OF RELEASE 7
8 9
10 11 44 45 80 PERSONNEL EXPOSURES NUMBER TYPE
DESCRIPTION
~
10 IO IO I LU
~N!....!.IA.:..__ ____________________
7 8 9 11 12 13 60 PERSONNEL lt-.lJURIES NUMBER
DESCRIPTION
EB I 010 IO II L.. ~N/....'...'.A ________________________
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7 8 9 11 12 BO OFFSITE CONSEQUENCES lili) t:.:N:.!..../A~------------------------------~
1 B 9 80 LOSS OR DAMAGE 10 FACILITY TYPE
DESCRIPTION
~UJ Ll~N~/A~--------------*------------~
7 8 9 10 BO PUBLICITY O?J N/A
_J 7 '8 9 80 ADDITIONAL FACTORS
~
!The health and safety of the public were not affected by this event because the three I 7
8 9 BO [iliJ !remaining power range channels were operable, accurate and provided the required (Con'tb 7
8 9 BO NAME:
T. L. Baucom PHONE: (804) 357-3184 GPO OBI. 667
r*
e e
4' r,,;..,
CAUSE DESCRIPTION (CONTINUED)
The output of the level and summing amplifier of channel N42 was found to have drifted low by a proportional voltage.
The channel was calibrated according to*
procedure and placed back on the line. It has since operated satisfactorily.
Since this is the first known failure of this particular circuit, no further action is deemed necessary at this time.
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The NIS System is provided by Westinghouse.
ADDITIONAL FACTORS (CONTINUED) degree of redundance necessary to operate the unit.
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