ML19323D435

LER 80-037/03L-0:on 800418,steam Generator Level Transmitter LTSP9A6 & LTSP9B6 to Steam & Feedwater Rupture Control Sys Found Out of Calibr.Caused by Zero Shift on Instruments Coupled W/Tightening of Tolerances.Instruments re-calibr

ML19323D435
Person / Time
Site:	Davis Besse
Issue date:	05/16/1980
From:	Trautman D TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19323D423	List: ML19323D422 ML19323D435
References
LER-80-037-03L, LER-80-37-3L, NUDOCS 8005210558
Download: ML19323D435 (3)

Text

_

U.S. NUCLE AR REGULATORY COMMISSION NRC FORM 766 (7 ??)

LICENSEE EVENT REPORT n

h CONTROL BLOCK: l l l l l l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) lo ltl l0 lH lD lB lS l1 l@l0 l0 l0 l0LICENSE l0 l0NUMBER l0 l0 l0 l0 l025l@l 26 4lLICENSE 1l 1lTYljPE1]@l Jo l

57 CAT 68 l@

7 8 9 LICENSEE CODE 14 15

' CON'T lolil 7 8 5$n"CE 60 l L l@l 0 l 5 l 0 l- l 0 l 369l 4 EVENT 61 DOOKET NUMBER 68 l 6 l@l DATE 0 l4 l1 l8 l8 l0 l@l0 l 5 l1 l 618 74 75 REPORT DATE 6J EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l o l 2 ] l (NP-33-80-46) On 4/18/80 at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> during Steam Generator Level to Steam and Feed- l 5031.16, Steam Generator l o 3 l water Rupture Control System (SFRCS) Refueling Calibration ST A check of the other l o 4 l Level Transmitter LTSE9A6 was found to be out of calibration.

J O J s j j seven revealed that only one additional level transmitter was out of calibration. Be-l o c ling in Mode 5, the station did not enter the action statement of Technical Specifica- l 10171 I tion 3.3. 2.2. There was no danger to the health and safety of the public or station l l

lo18l l personnel. Only two of the eight were out of tolerance.

DE CODE SUBC E COMPONENT CODE SUSC dE SU E l0l9l8 l C lH l@ y@ lG l@ l Il Nl S j T j Rl U[@ lT'l@ lZ l@

13 18 19 20 9 IO ti 12 7

OCCURRENCE REPORT REVISION SC - CNTI AL REPOR1 NO. CODE TYPE NO.

EVENT YE AR

@ su=R'Ro LE at 18101 823 10 13 17 l 24 26 W27 10131 28 29 IL 30 I l-l 31 W

32

_ 21 22 tET HOURS 22 S8 IT FOR1 S. SUPPL MANUFA TURER TAK ACTON ON PL NT

] g l Ylg l N jg [ N lg l Rl 3 l 6 l 9lg

[E 33 jg[34Z jg l35Z lg 36 3l7 0] 0] 0l -40 l 41 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h lilollThe cause was a zero shift on the two above mentioned instruments coupled with a tightqn-i i ling of tolerances a - a direct result of the recent change in steam generator low level ]

, 7 l bistable setpoints on 11/17/79, see LER NP-32-79-12 (79-105). On 4/18/80, LTSP9A6 wasl j

, 3 lrecalibrated per ST 5031.16. On 5/1/80, LTSP9B6 was recalibrated under Maintenance l

ii g4 i l Work Order IC361-80 to within specification. 80 y 7 8 9

% POWER OTHER STATUS is O RY DISCOVERY OESCRIPTION A S lB [glSurveillanceTestST 5031.16 i s y @ l0l 0l 0l@lNA l l ACTIVITY CO TENT AMOUNT OF ACTIVITY LOCATION oF RELEASE 1 s y ASED@OF RELE ASE[Z_jgl NA RELE l l NA l PERSONNEL EXPOS ES

~uM ER TYPE oESCRiPTiO~ @

, E 1010101@LZ' l@l _

NA l

,ERSO~NELimV4ES

! ~UMeER oESCRiPnON@ j NA FITl8 l9e l 0101@l12 7 11 80 LOSS OF OR DAMAGE TO FACILITY

, , ggl '5;"(" " 800521055% i 80 7 8 9 10 .

DESCntPTION 2 o ISSU E LN_. hl NA l. l l l l l l l l l I l l-l8035 10 68 65 7 8 9 Dadel hautman 419-259-5000, Ext. 235 2 DVR 80-069 runrts112refARJR< PHONE:

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE SUPPLEMENTAL INFORMATION FOR LER NP-33-80-46 PATE OF EVENT: April 18, 1980 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE: Steam Generator Level Transmitter LTSP9A6 and LTSP9B6 to Steam and Feedwater Rupture Control System (SFRCS) Out of Calibration Conditions Prior to Occurrence: The unit was in Mode 5, with Power (MRT) = 0 and Load (Gross MRE) = 0.

Description of Occurrence: On' April 18, 1980 at 1500 hours0.0174 days <br />0.417 hours <br />0.00248 weeks <br />5.7075e-4 months <br /> during Steam Generator Level to SFRCS Refueling Calibration Surveillance Test ST 5031.16, Steam Generator Level Transmitter LTSP9A6 was found to be out of calibration. At an applied differ-ential pressure of 359.4 inches differential pressure, which corresponds to the low level and trip setpoint, the output from Analog Amplifier AA01 in Steam Generator Level 7

j Instrument Cabinet Channel 1 was found to be 0.8338 volts DC, whereas the maximum amount allowed was .8245 volts DC.

I Further evaluation on April 27, 1980 of the maximum allowed amount showed an error in the calculation. As a result of this evaluation, one other Steam Generator Level Transmitter LTSP9B6 was found to be out of tolerance at this specific level.

~

Neither occurrence placed the unit in the action statement of Technical Specification 3.3.2.2 since it required the inoperable channel to be placed in the tripped condition within one hour in Modes 1, 2, and 3 only. The unit was in Mode 5 at the time of the occurrence. ,

l Designation of Apparent Cause of Occurrence: The apparent cause of the occurrence was determined to be a zero shift on the two above mentioned instruments coupled with a tightening of tolerances as a direct result of the recent change in steam generator low level bistable setpoints on November 17, 1979, see Licensee Event Report NP-32-79-12.

Analysis of Occurrence: There was no danger to the health and safety of the public or to station personnel. Of the total of eight steam generator level transmitters to the SFRCS, two of the eight were found to be out of the allowed tolerance. The actual levels displayed based on instrument tolerance and applied differential pressure were 4

rore conservative than the levels that would have been achieved on steam generator low l

level trips prior to changes made to _ steam generator low level bistable setpoints on November 17, 1979, s'e Licensee Event Report NP-32-79-12. The results of the safety avaluation performed based'on previous steam generator low level bistable setpoints have shown no cause for a safety concern.

LER #80-037 i ,

• . e

, - - - - ~ -

,c e ,- , . c -

1 ,

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE PAGE 2 SUPPLEMENTAL INFORMATION FOR LER NP-33-80-46 a

Corrective Action: On April 18, 1980, Level Transmitter LTSP9A6 was recalibrated per i

Surveillance Test ST 5031.16 to within specification. On May 1, 1980, Level Trans-mitter LTSP9B6 was recalibrated under Maintenance Work Order IC-361-80 to within apectfIcatLon.

Failure Data: There have been no previous occurrences of calibration problems with 4

l analog amplifiers.

LER #80-037 I

i h

l l

t i

I l

i J

.I I

l i

i .

. .,