ML20083Q956
| ML20083Q956 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek, 05000000 |
| Issue date: | 08/22/1972 |
| From: | Finfrock I JERSEY CENTRAL POWER & LIGHT CO. |
| To: | Anthony Giambusso US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML20083Q951 | List: |
| References | |
| NUDOCS 8303310147 | |
| Download: ML20083Q956 (2) | |
Text
-
f\\
. 46. -
- G V
P[' M s
y D
Tr, Jersey Central PogVtu? & Light Company klh I
M ADISON AVENUE AT PUNCH DoWL RO AD e MORRISTOWN, N.J. 07960 e 539-6111 i
August 22, 3972 js
'M
.[
l Mr. A. Giambusso
./g l
Deputy Director for Reactor Projects
) _. 4 Directorate of Licensing
["
q.
l United States Atomic Energy Commission A
Washington, D. C. 20545
\\/
//
\\<,
w7
Dear Mr. Giambusso:
/yi i
u
,w
Subject:
Oyster Crock Station Docket No. 50-219 lnoperability of 1 solation Condensors I
The purpose of this letter is to advise you of a failure of the isolation condenser system to function properly during'a recent plant cooldown.
' On August 9,1972, a plant cooldown ws in progress when, l
l at apptoximately 140 psig and 3600F, the main steam isolation valves were closed and an attempt was made to place the "A" isolation condenser in service. The condensate return valve opened but the "A"
isolation condenser rupture alarm was annunciated'and the condenser was automatically isolated./ Then, when an attempt was made to place the "B" isolation condenser in service, the condon-l sate return valve, V-14-35, would not open.
i Investigation of the incident revealed that the needle on the differential pressure gage for condensate line break sensor 1Bil, Al for the "A" isolation condenser was caught on the indicator over-travel stop, apparently having ranged upscale upon initiation of the l
condenscrs. The full scale deflection was due to the fact that n (f
enubber, which had been removed from the high side sensing.line for l'
sensors 1Bil Al and A2 to permit flou testing of the associated excess l
flow check valve, had not beer. replaced 7 Had the needle not caught l
on the stop, the sensor would have responded, as did its counterpart,
[
1Dil A2, and the isolation would not have occurred. The problem with
- ff.10 the "B" isolation condenser condensate return valve, V-14-35, was that_
p-the valve uns closed too tightly on its seat which caused the. breaker i.
to trip on overload when the valve was called upon to'open.
l lh The glass front cover was removed from sensor 1Bil Al', and the needle' removed from the pointer over-travel stop. When the needic moved downscale, the rupture alarm" reset. A calibration check was then performed on both condensate line break sensors for the "A" g/A inolation condcaser and the condenser returned ' to snrvice. The 3[o 0
4667
~
COPY SENT REGION 't
(- -
O 9
~
9
/
(['q
(
1 f
Q,'
Mr. A. Ciambuss'o Page II August 22, 1972 breaker for the "B" isolation condenser was checked and no abnormality was found. The setting of the breaker overloads was checked and found to be proper. The valve was operated and the various torque and limit switches were found to function properly.
At the time of this incident, the station was being shut down; thus, the action taken was consistent with Technical Specification requirements. The following actions are being taken to assure against a recurrence of this event:
1.
The snubbers from the instrument header sensing lines are being relocated to the individual sensing line connection for each differential pressure instrument. This modification will then permit flow testing of the associated excess flow check valves free from the effects of any snubber.
2.
A test at operating temperature and pressure has been conducted to determine that the magnitude and duration of the differentini
~
pressure transient sensed by the differential pressure instrumentation upon initiation of the isolatien condenser will not inadvertently trip the system.
3.
Isolation condenser valve operability tests, l
normally conducted at monthly intervals, are being conducted weekly during the next month l
to gain reassurance that the isolation con-denser will function when required.
l Uc are enclosing forty copics of this letter.
(
Very truly yours,
(/mf Of &
{
Ivan R. Finfr,ock,/ r.
Manager, Nuclear Generating Stations IRF/pk Enclosures I
cc: Mr. J. P. O'Reilly, Director Directorate of Regulatory Operations, Region 1
_j