05000346/LER-1979-118-03, Revised 79-118/03L-1:on 791126,when Reactor Coolant Pump Tripped,Reactor Protection on Sys High Flux Setpoint Reduced to 78.5% Full Power,Exceeding Limit.Caused by Procedural Deficiency Due to Incorrect Info: Difference between revisions

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#REDIRECT [[05000346/LER-1979-118-03, /03L-0:on 791126,after Low Level Alarm Received & Reactor Coolant Pump 1-2 Was Tripped,Flux Trip Setpoint Was Readjusted to Value Slightly in Excess of Tech Specs.Caused by Procedural Deficiencies.Mods Prepared]]
| number = ML19323H308
| issue date = 12/21/1979
| title = Revised 79-118/03L-1:on 791126,when Reactor Coolant Pump Tripped,Reactor Protection on Sys High Flux Setpoint Reduced to 78.5% Full Power,Exceeding Limit.Caused by Procedural Deficiency Due to Incorrect Info
| author name = Kocis R
| author affiliation = TOLEDO EDISON CO.
| addressee name =
| addressee affiliation = NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
| docket = 05000346
| license number =
| contact person =
| document report number = LER-79-118-03L, LER-79-118-3L, NUDOCS 8006120357
| package number = ML19323H305
| document type = LICENSEE EVENT REPORT (SEE ALSO AO RO), TEXT-SAFETY REPORT
| page count = 2
}}
{{LER
| Title = Revised 79-118/03L-1:on 791126,when Reactor Coolant Pump Tripped,Reactor Protection on Sys High Flux Setpoint Reduced to 78.5% Full Power,Exceeding Limit.Caused by Procedural Deficiency Due to Incorrect Info
| Plant =
| Reporting criterion =
| Power level =
| Mode =
| Docket = 05000346
| LER year = 1979
| LER number = 118
| LER revision = 3
| Event date =
| Report date =
| ENS =
| abstract =
}}
 
=text=
{{#Wiki_filter:m runm var U $. NUCLE AJ (dRL%/JV@LK/ RCulletR3 11118 LICENSEE EVENT REPORT ONTROL BLOCK: l l
l l
l l
lh (PLEASE PRINT CR TYPE ALL RECUlRED INF!RMATl!N) 8 6
o l i j l 0 l H l D l B l S l 1 l@l 0 l 0 l - l 0 l 0 l N l P l F l - l 0 l 3 l@l 4 l 1 l 1 l 1 l 1 l@l l
lg 8 9 LICENSEE CODE 14 15 L8 CENSE NUMBER 25 26 LICENSE TYPE JO b 7 CA T bd COYT 01 1_l 3[nN l Ll@l 0l 5 l 0 l - l 0 l 3 l 4 l 6 l@l 1 l l l 2 l 6 l 7 l 9 l@l1 l 2 l 2 l 1 l 7 l 9 l@
8 60 61 DOCKET NUMB E R (J
63 EVENT DATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h 10 l 2 l l On November 26, 1979, a low oil level alarm for Reactor Coolant Pump (RCP) 1-2 was l
6 o l3l l received.
Reactor power was reduced and the RCP was tripped. The Shift Foreman in-l O l4 l l structed personnel to reduce the Reactor Protection System (RPS) high flux setpoint l
l i
o l s t l to 78. 5% of full power. During a log review at 0800 hours on 11/27/79, it was found l
l o l6 l l that the value of 78.5% was in excess of the 78.3% value allowed by Technical Specifi ;
o l1] l cation 2.2.1 for three RCP operation. There was no danger; the ectual setpoints ex-l o is l l ceeded the tech spec value by 0.08% of the allowed value.
(NP-33-79-135) l 8 9 80 SYSTEM
 
==CAUSE==
CAUSE COMP.
VALVE CODE CODE SUBLOOE COMPONENT CODE SUSCODE SUBCODE 019]
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8 9
10 II 12 13 13 19 20 SEQUENTIAL OCCURRENCE REPORT REVISloN EVENT YEAR REPORT NO.
CCDE TYPE N O.
O" y"LE R < RO l7l9l
[ _j l1 l1 l8l l -l l0 l3 l lL l 9
W tugAT
_ 21 22 23 24 26 27 28 29 30 31 32 iX N ACT ON ON PLANT T
HOURS 22 5 B IT FoR B.
SUPPLIE MAN 1ATRE3lg l E lglJ4G lg l Z lg lZl@
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i 33 33 36 J/
40 4i 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h ilall The setpoints were readjusted to within the allowable value by 0850 hours on 11/27/79.l t
gl The cause of the incorrect setpoint setting has been attributed to procedural defici-!
gl encies in that correct and concise information was not provided. Appropriate pro-l
,13l l cedure modifications have been prepared to correct these deficiencies.
ital l l
8 9 80 SA S
% POWER oTHER STATUS DIS O RY DISCOVERY DESCRIPTION iTs1 l El@ l 0l 6 l 8 l@l NA l
lB [gl Routine log review l
ACTIVITY CO TENT r"N m.!?MO Or nt Lt.ot AMOUNT OF ACTIVITY LCCM.o.10F RELEASE @
iTel U @ l zl@l NA l
i NA 7
l 8 9 to 11 44 45 80 TERSONNEL EXPOSURES NUMBER TYPE
 
==DESCRIPTION==
iTl 1 01 el el@Lz J@l "A
I PERSONNEt INJURIES NUMBER
 
==DESCRIPTION==
g l 0l 0l 0l@l NA l
8 9 11 12 80 LOSS OF OR DAMAGE To FACILtTV TY/E
 
==DESCRIPTION==
LL9.J LzJ@l NA l
8 9 10 80 ISSUE
 
==DESCRIPTION==
E LN_j @ l NA l
llllllllll lll5 8 9 10 68 69 80 ;;
VR 79-178 &nRQ7 Men Kods W4WN M N {
PREPAREn
: pgogg, 8006120%r7
 
TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR PO'<!ER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-79-135 DATE OF EVENT:
November 26, 1979 FACILITY:
Davis-Besse Unit 1 8
IDENTIFICATION OF OCCURRENCE: After tripping Reactor Coolant Pump (RCP) 1-2, the flux trip setpoint was readjusted to a value slightly in excess of technical opecifications Conditions Prior to Occurrence: The unit was in Mode 1, with Power (MWT) = 1885 cnd Load (Gross MWE) = 638.
Description of Occurrence:
At 2145 hours on November 26, 1979, a motor lower bearing oil level alarm low (L808) for RCP 1-2 was received in the control room. As dictated by the immediate action of EP 1202.16 RCP and Motor Emergency Procedure, reactor power was reduced and RCP 1-2 was tripped.
Instrument and Control personnel were then called to lower the flux trip setpoint corresponding to three RCP operation.
By 0000 hours on November 27, 1979, the new flux trip setpoint value was obtained from the Shif t Foreman and the trip bistables were reset.
During log review at 0800 hours on November 27, 1979, the 78.5% setpoint value ob-teined from the Shif t Foreman was discovered to be in excess of 78.3% which is the maximum allowed per the Technical Specification 2.2.1 for three RCP operation.
An cdditional setpoint adjustment was completed by 0858 hours on November 27, 1979, to lower the trip bistable setpoint within technical specification requirements.
?
(
Designation of Apparent Cause of Occurrence: The cause for incorrectly setting the flux trip setpoint has been attributed to procedure deficiencies in that correct and concise 3
information was not provided.
The EP 1202.16, RCP and Motor Emergency Procedure used during the trip of RCP 1-2 does not relate a need for resetting the trip setpoints to
'cny value or specify the value.
Analysis of Occurrence: There was no danger to the health and safety of the public cr to station personnel.
By the procedure, trip voltages set into the bistable may h;ve a tolerance of (+) 0.000 VDC to (-) 0.060 VDC with respect to the percent rated thermal pow'er desired. This maintains tapt the actual setpoint applied may be more c:nservative than that specified.
In this case, the actual voltage to which the bistables were set corresponds to 78.46% of rated thermal power.
This value exceeds tschnical specifications (by.08% of the allowable value) which is. expected to be within safety margins.
Carrective Action: Modifications will be prepared to the RCP and Motor Emergency
. Procedure EP 1202.16 and Power Operation PP 1102.04 to reflect technical specifica-tisn requirements for three RCP operation flux trip setpoints.
Failure Data: There have been no previously reported procedural difficulties con-c;rning reactor protection system high flux trip setpoint.
i LER #79-118
~
}}
 
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Latest revision as of 23:01, 3 January 2025