ML19270F840

LER 78-040/03L-1 on 780422:review of Reactor Operator Log Determined That Group 5 Control Rods 100% Zone Ref Light Had Not Been Checked at Required Frequency.Caused by Personnel Error.Process Computer Reminder Program Developed

ML19270F840
Person / Time
Site:	Davis Besse
Issue date:	05/18/1978
From:	Marley J TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19270F837	List: ML19270F836 ML19270F840 ML19270F841
References
LER-78-040-03L, LER-78-40-3L, NUDOCS 7903270600
Download: ML19270F840 (2)

Text

NRC F ORM 366 (7 77)

LICENSEE EVENT REPORT

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CONTROL BLOCK: l

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l D l B l S l14 1 l@l LICENSEE CODE 15 0 ] 0 l - l LICENSE 0 l 0 lNuMBEH N l P l F l - l 025] 3 l@l 26 4LICENSE JU $ 7 C A T 58 CON'T 7

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bd 69 EVENT OATE 74 75 REPORT DATE 80 EVENT DESCRIPTION AND PROBABLE CONSEQUENCES h l o l 2 l l While reviewing the Reactor Operator Log on 4/22/78, it was discovered that the Group [

[olal l 5 Control Rods 100% Zone Reference Light had been last checked on 4/21/78 at 2220 [

o 4 I hours.

Since Group 5 was in asymmetric bypass, TS 3.1.3.3, Action a.2.b requires thatl o s Group 5 position be verified at least once every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. There was no danger to l The control rods of Group 5 g l o is l l the health and safety of the public or unit personnel.

O 7 l were not in an asymmetric Condition. (NP-33-78-50) l

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o s i 80 7 8 9 COMP. VALVE SYSTEU CAUSE CAUSE  %

CODE CODE SUBCODE COMPONENT CODE SUSCODE SU8 CODE lojol l Rl B j@ W@ l A l@ lI lN lS lT lR lU l@ l Zl@ W @

13 18 13 20 8 9 to it 12 7

OCCURRENCE REFORT REVISION SEQUENTI AL

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REPOHT NO. CODE TYPE No.

EVENT YE AR LER RO

@ gtar 17 8I l-l 23 1014l0[

24 26 l/l 27 l 0l 3 28 29 lLl 30 l-l 31 W32

_ 21 22 HOURS 22 S B IT FOH 9 UB. SU PPLI E MAN FA TL RFR Er7 A ON PL A T TH A T lZlh 1 0 l0 l0 9I40 Y

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33 34 35 J6 3/ di 42 43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS i o lThe apparent cause of this occurrence was personnel error. The operator inadvertently [

i i l failed to perform the required observation of the zone reference light. An operator [

at 2117 hours0.0245 days <br />0.588 hours <br />0.0035 weeks <br />8.055185e-4 months <br /> on April 22, 1978. A l

,,,7glwas dispatched to read the zone reference light

,,;3; l program has been developed for use by the process computer to aid operators in moni- l

,,g,j ltoring surveillance tests required at frequent intervals when the unit is in Statement.83 an Action l 7 8 9 oTHE R STATUS ISCOV R DISCOVERY DESCRIPTION A S *. PoWE R 4 l A [Ql Operator Log Review l li 15l W @ l 0l 6l@l NA l ACTIVITY CONTENT AMOUNT OF ACTIVITY LOCATION OF RELE ASE RELEASED OF RELE ASE NA l l

7 1 6 8 9 W @ lZ10 l@l NA 11 44 45 80 PERSONNEL E XPOSURES NUVHE R CESCRIPTION I

i 7 1010 0_j@lZ TYPE l @lNA '

' ' ' ,ERSONNEl'IN;unS

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~UveEn DESCniPTiON@ l NA 7

i R 8 9 1010 Ol@l 11 12 80 Loss OF On DAYAGE To F ACILITY TYPE DESCniPTION NA l i o

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Pumav 7 9 0 3 27 0 6cro sacosecyty

• I IIIIIIIIII!l,i 2 o ISSU

[jij E D@DE SCRIPTION l NA 68 69 63 3 7 8 9 to DVR 78-064 Y PHON E:

419-239-5000. Ext. 276 {

NAME OF PREPARER

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TOLEDO EDISON COMPANY I DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION i SUPPLEMENTAL INFORMATION FOR LER NP-33-78-50 DATE OF EVENT _: April 22, 1978 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE:

Failure to read zone reference light for Group 5 Control Rods when in asymmetric bypass e

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The unit was in Mode 1, with Power (MWT) = 1269 Conditions Prior to Occurrence:

and Load (MWE) = 385.

Description of Occurrence:

While reviewing the Reactor Operator Log on April 22, s 1978, it was discovered that the Group 5 Control Rods 100% Zone Reference Light had been last checked on April 21, 1978 at 2220 hours0.0257 days <br />0.617 hours <br />0.00367 weeks <br />8.4471e-4 months <br />. Since Group 5 was in asym-metric bypass, Technical Specification 3.1.3.3, Action a.2.b requires least that Group once 5

be maintained at 0%, 25%, 50%, 75% or 100% withdrawn and verified at every 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The position of Group 5 had not been verified by the 100% Zone Reference Light for approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Designation of Apparent Cause of Occurrence: The apparent cause of the occurrence was personnel error. The operator inadvertently failed to perform the required observation of the zone reference light.

Analysis of Occurrence: There was no danger to the health and safety of the public or unit personnel. The control rods of Group 5 were not in an asymmetric condition.

Only the Absolute Position Indication for one control rod was defective requiring operation in asymmetric bypass.

Corrective Action: As soon as it was discovered that the zone reference light had not been read, an operator was immediately dispatched to read the zone reference light at 2117 hours0.0245 days <br />0.588 hours <br />0.0035 weeks <br />8.055185e-4 months <br /> on April 22, 1978. A program has been developed for use by the 1 process computer to aid operators in monitoring surveillance tests required at fre-quent intervals when the unit is in an Action Statement.

Failure Data: This is not a repetitive occurrence.

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LER B78-040

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