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Entergy Corp.—owner and operator of the Indian Point nuclear power plant located in Buchanan, N.Y.—announced on February 6 that it had discovered elevated levels of tritium in samples from three of its groundwater monitoring wells at the facility.

The samples were taken as part of the plants ongoing comprehensive groundwater-monitoring program. Although the company said that the effect of the elevated values was less than 0.1% of federal reporting guidelines, it voluntarily notified the Nuclear Regulatory Commission (NRC), state agencies, and key stakeholders of the test results.

In a statement, Gov. Andrew Cuomo—who has been a vocal critic of the plant—said: “The company reported alarming levels of radioactivity at three monitoring wells, with one well’s radioactivity increasing nearly 65,000 percent. The facility reports that the contamination has not migrated off site and as such does not pose an immediate threat to public health.”

History of Leaky Piping

It’s not the first time Indian Point has had to deal with water leaking into unintended areas. In February 2009, Entergy plant operators discovered water leaking from a buried section of piping associated with the condenser hotwell reject line to the Unit 2 condensate storage tank.

Entergy determined that much of the leakage had gone through the plant’s storm drain system and flowed to its discharge canal. To correct the problem, the area around the leak location was excavated, the affected pipe section was replaced, and the system was returned to normal in a little less than a week’s time.

The company’s root cause investigation concluded that the protective external pipe coating that was applied at the time of original construction had failed, resulting in external corrosion in a localized area. A potential contributing factor was that backfill—placed around the pipe during installation—contained rocks up to eight inches in diameter. Investigators suspected that the large rocks likely damaged the pipe coating during installation, allowing corrosion mechanisms to act on the unprotected metal surfaces.

In that instance, the section of piping was also at a low point, which was close to the water table. Damp or wet conditions may have accelerated general corrosion of exposed carbon steel.

One of the company’s first corrective actions was to update the backfill specification. The company also implemented a buried piping and tank inspection program, including the use of improved inspection techniques.

Tag(s) : #Nuclear
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