ML19257B375

Suppl to ROs 50-219/79/10-3L & 50-219/79/26-3L:radioactivity from Pipe Leaks Contained within Area of Excavation.Concrete Floor & Walls of Vault Enclosure Poured,Ensuring Containment of Radioactivity in Case of Leaks

ML19257B375
Person / Time
Site:	Oyster Creek
Issue date:	01/15/1980
From:	JERSEY CENTRAL POWER & LIGHT CO.
To:
References
RO-50-219-79-26, NUDOCS 8001150626
Download: ML19257B375 (1)

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SUPPLEMENT TO REPORTABLE OCCURRENCE REPORT NO. 50-219/79/10-3L AND NO. 50-219/79/26-3L ANALYSIS OF Prior to any digging in the area, core samples were.taken at OCCURRENCE: varying depths. Sample analyses showed no activity above normal background. Samples of soil and water taken during the initial excavation showed detectable activity in the immediate area of the DWEDT line. As excavation continued, sampling and analysis of the soil shmed Co60 and Csl37 to be present in trace amounts.

Since no effo' sas made to segregate the dirt during the excava-tion, it was ns. possible to determine how localized the activity was. Accurate assessment of contamina* bn was hampered by the discovery of another leak on August 7,1979.

When excavation reached the level of the water table, dewatering was started. Theinitialwatg7.amplestakenduringthisoperation s

showed detectable Co 60 and Cs This is somewhat attributable to residual contamination in the hole from the digging. It was also realized that sample bottles frcm the chemistry laboratory were used to collect samples. These had previously been used for radioactive samples. As dewatering continued, only scattered trace activity was detected at background levels. Sampling and low level analysis at the plant is severely limited due to the close proximity to sources of contamination as well as counting instrument background. The background levels observed in water samples support the belief that radioactivity from the pipe leaks did not get into the water table. This was further substar.tiated by analysis of water from the Oyster Creek domestic water well during this period which showed no detectable. levels of radioactivity.

At completion of excavat' ion, several soil samples were obtained from the bottom of the pit. They showed no detectable lev tls of activity. From the sampling and analysis performed during the project, it is concluded that radioactivity released from the pipe leaks was contained within the area of the excavation. It actually was highly localized in the vicinity of the leaks and only found at other points as a result of the excavation and repair work being performed in the area.

CORRECTIVE Following the analysis of the final soil samples, the concrete ACTION: floor and walls of the vault enclosure were poured. This insured containment of radioactivity in the event of any further pipe leaks.

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