05000346/LER-1979-080-03, /03L-0 on 790716:safety Features Actuation Sys Containment Radiation Detector Re 2005 Spiked & Tripped Channel 2 Containment Radiation Bistable.Caused by Component Failure.Detector Will Be Relocated Outside Containment

/03L-0 on 790716:safety Features Actuation Sys Containment Radiation Detector Re 2005 Spiked & Tripped Channel 2 Containment Radiation Bistable.Caused by Component Failure.Detector Will Be Relocated Outside Containment

ML19242D607
Person / Time
Site:	Davis Besse
Issue date:	08/10/1979
From:	Eldred D TOLEDO EDISON CO.
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
Shared Package
ML19242D606	List: 05000346/LER-1979-080, Forwards LER 79-080/03L-0 05000346/LER-1979-080-03, /03L-0 on 790716:safety Features Actuation Sys Containment Radiation Detector Re 2005 Spiked & Tripped Channel 2 Containment Radiation Bistable.Caused by Component Failure.Detector Will Be Relocated Outside Containment
References
DVR-79-112, LER-79-080-03L, LER-79-80-3L, NUDOCS 7908150504
Download: ML19242D607 (2)

LER-1979-080, /03L-0 on 790716:safety Features Actuation Sys Containment Radiation Detector Re 2005 Spiked & Tripped Channel 2 Containment Radiation Bistable.Caused by Component Failure.Detector Will Be Relocated Outside Containment

Event date:
Report date:
3461979080R03 - NRC Website

text

U.S. NUCLE AR HEGULATORY COMMI I RC FORM 366

. /)

LICENSEE EVENT REPORT CONTROL BLOCK: l l

l l

l l

l (PLEASE PRINT OR TYPE ALL REQUIRED INFORMATION) 6 l0 lH lD lB lS l1 hl 0\\ 0l -l 0l @l Nl Pl Fl -l 0l 3l@l4 l1 l1 l1 l1 l@l l@

I 23 26 LICENSE TY PE JO Si L A T 58 3

1 LICENSE NUM8EH 8 9 LICENSEE CODE 14

~5

$RCE lL hl0l510l-[0i3l4 l6 @ l0 l7 il 16 l7 19 @l0 l 8 l 1 l 0 CON'T 80 14 75 REPORT DATE 3

1 66 63 EVENT DATE 60 61 COC A ET N#.*d E R 8

EVENT DESCRIPTION AND PROB ABLE CONSEQUENCES h the Safety Features Actuation System (SFAS)

'ntainment i

l On 7/16/79 at 0613 hours0.00709 days <br />0.17 hours <br />0.00101 weeks <br />2.332465e-4 months <br />, o

2 Radiation Detector RE 2005 spiked, tripping the SFAS Channel 2 Containment Radiation o

3i l At 0613 hours0.00709 days <br />0.17 hours <br />0.00101 weeks <br />2.332465e-4 months <br />, I The indication of RE 2005 immediately returned to normal.

o 4

l Bistable.

in Action State =ent of Technical RE 2005 was declared inoperable placing the unit I

o 5 l Specification 3.3.2.1.b9.

The bistable was lef t in the tripped condition. There was jno io e

e r so nnel.

The other thrae j danger to the health and safety of the public or station 1

io 7

l (NP-33-79-92) 1 SFAS containment radiation instrument strings were operable.

30

o a l CCVP.

VALVE 7

8 9 SYST EM

CAUSE

CAUSE CODE CODE SUBCODE COMPONENT CODE SUBCODE SU8 CODE 11B lh Ch l Elh l T l N l S l T f l U l h (E_j h I Zl h o

9 18 13 20 7

8 9

to 11 12 13 REVISION CL. uR R E NCE REPORT SEQUENTI AL CODE TYPE N o.

O,ay?S I7191 M

10 18 10 l W

1013I IL I B

10 I hEPORT NO.

_ EVENT YEAR LE R cRO

_ 21 22 2J 24 26 27 23 29 30 J1 32 E

ATTACHVENT NF R O-4 PR1VE COUP.

COVPON E N T TAKEN ACTION ON PL ANT VETHCD HOURS SU S N*t TT E D FOR*Adub.

SU PP LI E R VANUFACTURER ACTION FUTURE EFFECT SHUTDOWN

[ XJgl34A l g l35Z lg l36Z l@l 0] O O

l l Y lg l2Y l(g l A l@

lVl1l1l5l@

31 40 41 4

43 44 47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS h 33 failure of the detector, which is located within the j l The apparent cause is component i

o The root cause Uf this occurrence cannot be determined as the detector

]

l1 111 ] containment.

The detector will be relocated outside of

,l is inaccessible during power operation.

, 7 l

78-306.

j conta incent under Facility Change Request 3

l i

i 4

l 80 7

8 9 Of SCoVERY DESCRIPTION ST A S

% POWER oTHER STATUS SO RY Aj@l Operator observation

}

li is l ]@ l 0l 9 l 5 l@l NA ACTiv 4 TY CO TENT LOCATION OF RELE ASE RELEASED CF RELE ASE AVOUNT OF ACTivlTV l

l l

NA l1 l6l W @ W@l NA 80 44 45 7

8 9 10 11 PERSONNEL E XPOSUR ES I

NUVBE R

DESCRIPTION

1010 01@l ZTYPE @l NA 80 i

7 PERSONNE L IN BES NUV8E R D E SCR t P TION l

ITT l l 0 I 0101@l NA LOSS OF CR OAVAGE To FACILITY O 5 C3 7908150 fCl/

f 7

8 9 11 T2 6

l TYPE

DESCRIPTION

(Z_J@lNA g

1 9 7

8 9 10 l

lllll!lIIf IIl#

ISSUE @DESCRIPTtON lm a ;

u o 7

8 9 m

N'Ut-237 f, David T. Eldred PHONE

- 2 N A*.'E OF PREP ARER

TOLEDO EDISON COMPANY DAVIS-BESSE NUCLEAR POWER STATION UNIT ONE

_ SUPPLEMENTAL INFORMATION FOR LER NP-33-79-92 DATE OF EVENT:

July 16, 1979 FACILITY: Davis-Besse Unit 1 IDENTIFICATION OF OCCURRENCE:

Safety Features Actuation System (SFAS) Channel 2 Containment Radiation Detector RE 2005 spiked Conditions Prior to Occurrence:

The unit was in Mode 1, with Power (MWT) = 2625, and Load (Gross MWE) = 874.

Description of occurrence: On July 16, 1979, at 0613 hours0.00709 days <br />0.17 hours <br />0.00101 weeks <br />2.332465e-4 months <br />, SEAS Channel 2 Contain-ment Radiation Detector RE 2005 spiked (tripping the SFAS Channel 2 Containment Radia-tion Bistable) and returned to normal. Several prior spikes and resulting Channel 2 Containment Radiation Bistable trips had occurred in the late evening of July 15, 1979, and the morning of July 16, 1979.

In each case, the indication of RE 2005 returned to normal and the trip was manually reset. Upon receiving the trip at 0613 hours0.00709 days <br />0.17 hours <br />0.00101 weeks <br />2.332465e-4 months <br /> on July 16, 1979, RE 2005 was declared inoperable. This placed the unit in Action Statement of Technical Specification 3.3.2.1.b9 which requires the operability of all four SFAS contai, ment radiation instrument strings in all modes. The SFAS Channel 2 containment radiacion bistable was left in the tripped state as required by the Action Statement.

The containment radiation instrunent s :cings associated with the other three SFAS channels were operable, meeting the minimum operational requirements-Designation of Apparent Cause of Occurrence: The apparent cause of this occurrence is component failure of the detector.

The detector is located inside the containment and is therefore inaccessible during power operation so the exact mode of failure can-not be determined at this tbne.

Analysis of Occurrence:

There was no danger to the health and safety of the public or to station personnel.

The containment radiation monitoring instrument strings associated with the other three SFAS channels are operable.

RE 2005 ialled in the high (safe) direction.

Corrective Action

The containment radiation bistable of SFAS Channel 2 remains in the tripped state as detector RE 2005 is inaccessible during power operation. Main-tenance Work Order IC-344-79 has been written to replace the detector when contain-ment access becomes possible.

Facility Change Request 78-306, which will relocate the detect. ors outside containment to allow access during power operation is presently being implemented.

Failure Data: A previous failure of RE 2005 was reported in Licensee Event Report NP-33-78-140.

LER #79-080 t

f.,

u oG& iO