ML19343C354
| ML19343C354 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 05/29/1974 |
| From: | JERSEY CENTRAL POWER & LIGHT CO. |
| To: | US ATOMIC ENERGY COMMISSION (AEC) |
| References | |
| AO-50-219-74-31, NUDOCS 8103120365 | |
| Download: ML19343C354 (2) | |
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OYSTER CREEK NUCLEAR GENERATING STATION FORKED RIVER, NEW JERSEY 08731 Abnormal Occurrence Report No. 50-219/74/31 Report Date May 29, 1974 Occurrence Date May 19, 1974 Identification of Occurrence Inoperability of two Bergen-Paterson hydraulic shock and sway arrestors located on Core Spray System II and on Containment Spray System I in the reactor build-ing. This event is considered to be an abnormal occurrence as defined in the Technical Specifications, paragraph 1.15D.
Conditions Prior to Occurrence The plant was shut down for refueling.
Description of Occurrence During an inspection of the snubbers in the reactor building, two inoperable units and five leaking units, all Bergen-Paterson Type HSSA-10, were found.
The defective snubbers were identified as follows:
Unit System Condition Elevation 477287 Containment Spray I Inoperable
-19' 469873 Containment Spray II Leaking 23' 469903 Shutdown Cooling Leaking 51' 469846 Core Spray II Leaking 75' 469855 Core Spray II Inoperable 75' 487465 B Emergency Cond.
Leaking 75' 477170 A Emergency Cond.
Leaking 75' Apparent Cause of Occurrence The cause of this occurrence is attributed to seal failure. The inoperability of the snubbers was due to a loss of the hydraulic fluid. The core spray unit had never been rebuilt with ethylene propylene (EP) seals. The containment spray glos /2 03W
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Abnormal Occurrence No. 50-219/74/31 Page 2 unit had been partially rebuilt with EP material following an inspaction on February 28, 1974. The particular snubber series involved cannot be fully. re-built with EP material. Several seals peculiar to the series are no longer fabricated by the snubber manufacturer.
Analysis of Occurrence The safety significance of this occurrence was a partial loss of the seismic restraining ability for the affected systems. Had the plant suffered a design basis earthquake, the prcaability that these systems would have suffered structural damage was increased.
Corrective Action The immediate corrective action was to replace the seven faulty units with units which are equipped with EP seals and have been pressure tested to 4000 psig.
The monthly inspection of all hydraulic snubbers located outside of the primary containment vill be adhered to regardless of plant status. Those units which require maintenance and are found to contain other than EP seals will, to the extent possible, be replaced with units having all EP seals. Eventually, any tmit which cannot be fully equipped with EP seals will be retired.
The Generation Engineering Department is currently evaluating mechanical snubbers as possicle replacements for hydraulic snubbers.
Failure Data Manufacturer:
Bergen-Paterson Type:
HSSA-10
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