ML19329B630
| ML19329B630 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 06/11/1977 |
| From: | Batch S, Lingenfetter J TOLEDO EDISON CO. |
| To: | |
| Shared Package | |
| ML19329B551 | List: |
| References | |
| NUDOCS 8002050746 | |
| Download: ML19329B630 (2) | |
Text
.
--O
'
.
.. .. .
.h ; ,
LICENSEE EVENT RET' ORT
.
t
\
-
J. .
.\p' CoNsnoteLoCa. j i i lj -
.
c m.w
.
..a , ~.. ... ' ,n.~e ,n .~,- \
@jolH I DIB I S ilj G jij- 010 ! !!! ? iF I -10 l 3l lj l 1 1 1g 1 p]
-
CA, co.e m : :.= ;; .,o c . . . . . . . .N....... ...o.,o-,.
(o i Co*'t._JQ 1 SJ w LTJh2 1.LJ w l01 68 5 ! C i ._! c i 34i 1 6 64 1 to i 512 I817:7 69 Je I36.toisitil17 g c, t ytNT Uf SCaiPT'CN . .
g i While recalibrating RCS pressure bistables. a simulated pressure signal
_
!
es , s
@ l rose: HV-Dilli s,troked closed. Operations immediately tripped Decay Heat :
> ss -a
[jg[ Pump. HV-DHil was re-opened. Decay Heat Pump restarted and 3000 gpa fle r s ee a
[ojg i to the RCS re-established. NP-32-77-3. !
s u EL
'
__
'
-
- Iuo.." 'c'nTc' c n-~, . C o o, 'd5.6;" I,50:;'c /"',
o n iz i z.! LDj i zi z i zi z iz i z i z iziziz izi , ,,g, . . ..
i e s iu n u o . .. .i o
.
'
- -
Caust otscaietion t The calibration _pr_ocedure did not provide instructions for jurpering out i
_
ae
@j)[ this int,arlock to prevent closing'of HV-DH11 (procedure inadecuacy). N 1 is iG
\ eel - '
7 89 oJ
)
Se US s e' owe e ovest a s? Atus ues oIt a v Disc ovt a v :1HC asetsom ii I B_j [0lO!Ol I NA. l (zj NA f 7 G s to I2 33 e4 41 -[d a 40 2:e eYw e g..,
- t ae r mtAtASto os ns (45g amoums or activetv toc Alto *e or et LL ASC
,@ LZ_J . 1_Z j ! NA I l NA l 1 8 s 10 ft 44 46 a.J P( A$o*#Ntt (IPC$Unt$
seuw.se e 1 w et cf SC SI8?'or.
I sesLO i 0:u0 1 oil i NA )
i2 a P( A$QNN(t ar4 Junt($
P.vu o t eL C*t %C 8 88 f 8 N 8 1e301010! o
! uNA I s, a Of F187t
'
, EE.( "^ con 5touf NCES
.
l LOSloM O AwaG170 8 ActLaty
- evre euc a.. ion I "
P D,yu LNA . .J .
PuollClf v
- 81 s es NA -
i
. u 400illoNat s aCTUAS *
- I NA -
l eo u (G )
E.DeaL y
% Jacque Lingenfelter/Stan Batch (4197 ' 259-5000. E:(t . 251
.
l
~
8 0 02 05014b - . . ..
-, . - ,--
-. ,, .
.
. .s
.-
S *
\
TOLEDO EDISON COMPA!N DAVIS-BESSE UNIT ONE NUCLEAR POWER STATION
- SUPPLEMENTAL INFORMATION FOR LER NP-32-77-3 DATE OF EVENT: May 28, 1977 FACILITY: Davis-Besse Unit 1 -
~
IDENTIFICATION OF OCCURRENCE: 'While recalibrating SFAS Channel 4, a simulated pressure signal rose above setpoint 433 psig; HV-DHil stroked closed and Decay Heat Punp 1-2 tripped causing a situation in violation of Technical Specifica-
- tion 3.4.1.
I Conditions Prior to Occurrence: The plant was in Mode 5. Power (MRI)0 - Power
! (MWE)D. RCS Pressure less than 200 psig.
.
.
Description of Occurrence: At 0045 Hours, May 28, 1977, an I&C mechanic was i
'
workfag on SFAS Channel 4, recalibrating the RCS pressure bistables. As the simulated pressure rose, KV-DH11 stroked closed at its setpoint of 433 psig.
Oper.stions immediately tripped decay heat pump. ,
i
\s_ / Designation of Anoarent Cause of Occurrence: This event has been determined to have been caused by'a procedural inadequacy in Maintenance Instruction I 1-1701 Analysis of 'ccurrence:
O The closing of DH 11 and subsequent de-energi:ation of Decay Heat Pump 1-2 caused decay heat flow to be less than 2800 gpm for three minutes. Since flow was not needed for decay heat removal and Decay Heat Pump
'
l-2 was re-started, no threat resulted to the health and safety of the public or station personnel.
Corrective Action: I&C mechanic i= mediately reset the bistable, operator re-opened HV-DH11, restarted Decay Heat Fump and re-established 3000 gpm flow to RCS. Maintenance Instruction I l-1701 was modified to defeat the DH 11 valve logic by utilizing a jumper across the ' interlock.
Failure Deta: DH 11 was inadvertently closed on May 27,1977 (LER NP-32-77-2) ,
but the cause was a wiring installation error, not a procedure error as caused this occurrence.
.
%/
)
! .
.
'
,
.
. I
- - - - .
_- , , _ .