ML19347C802
| ML19347C802 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 01/23/1974 |
| From: | Rone A JERSEY CENTRAL POWER & LIGHT CO. |
| To: | |
| References | |
| AO-50-219-74-6, NUDOCS 8103040596 | |
| Download: ML19347C802 (3) | |
Text
___---.
Initici Telcph::ns Deta cf
, Report Dato:
1fi f4 Occurr:.nca:
1/22/74
- Initial Written
' Time of Report Date:
1/23/74 0.ccurrence:
1000 OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/ 6 ICENTIFICATION Violation of the Technical Specifications, paragraph 3.5.A.6 OF OCCURRENCE:
Twenty-four hours after placing the mode selector switch into RUN, the torus atmosphere contained 6.2% 0, which is above 2
the limit,of S.0% 0 -
2
'Ihis event is considered to be an abnormal occurrence as de-fined in the Technical Specifications, paragraph 1.158 CONDITIONS PRIOR TO OCCURRENCE:
Steady State Power Routine Shutdown Hot Standby Operation
, Cold Shutdown Load Changes During Refueling Shutdown Routine Power Operation y
Routine Startup Other (Specify)
Operation i
Reactor Power
- 1075 MWt =340 MWe E
- 7.4 X 10 Recirculation Flow
- 3.8 X 10' gpm lb/hr Feedwater Flow Feedwater Temperature - 275 F Reactor Pressure
- 1020 psig Reactor Water Level
- 78" Yatvay c
DESCRIPTION At 2030 on January 21, 1974, the primary containment inerting OF OCCURRENCE:
process was initiated by first performing a calibration on the torus /drywell 02 analyzer, as per the operating procedure. The torus atmosphere was then inerted with nitrogen to 4.8% 02 as indicated in the drywell/ torus oxygen recorder and drywell inerting was then co[nmenced.
During this process, a "zero check" on the analyzer showed that the instrument "zero" was low. Correcting this condition brought the indicated 02 level 7to3ofo6%
i Abntraal Occurrznca Report No. 50-219/74/ 6 Page 2 in the torus to 6.2%.
Since drywell inerting was already in j
progress, it was decided to reinert the torus after drywell inerting.was complete.
Due to a misunderstanding on the part of the duty Shift Foreman, an attempt was made to inert the dry-
'well to less than 1% 02 content.
Prior to attaining this con-dition, the plant nitrogen supply reached a level where further consumption in the inerting process would have exhausted the operational supply needed for the nitrogen / air system in the drywell.
An orderly plant shutdown was started 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after going into the RUN mode at 1000 on January 22,1974 at a 30 MNe/hr. rate.
Power was reduced to 292 hWe at which time a temporary Techni-cal Specification change was obtained which allowed operation at 50% reactor power with greater than 5% 02 concentration in the primary containment until 1230 on January 24, 1974.
APPARENT CAUSE Design Procedure OF OCCURRENCE:
Manufacture Unusual Service Condition Installation /
Inc. Environmental Construction Component Failure
~~
X Operator Other (Specify)
The duty Shift Foreman in charge of this operatior, misjudged the capacity of the plant nitrogen system.
In addition, the Foreman was informed that a nitrogen truck was enroute and would arrive Tuesday morning with the additional nitrogen needed to complete the inerting process.
Unfortunately, due to internal problems, the nitrogen vendor was unable to meet the required delivery time.
n Abn:rmal Occurrsnca Report No'. 50-219/74/ 6 Paga 3 ANALYSIS OF The significance of this event lies in operating the reactor OCCURRENCE:
at power with an inadequately inerted containment which, under design bases LOCA conditions, would have created a condition whereby the probability of experiencing an explosive concen-tration of oxygen and hydrogen in the containment would have been increased.
CORRECTIVE ACTION.
Corrective action to prevent recurrence of this event is to be determined after the appropriate review process by the Plant Operations Review Committee.
FAILURE DATA.
Not applicable.
4 9
9 Prepare d by:
Md Date:
/
79