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Xcel Energy to begin construction on underground barrier at Monticello nuclear plant

Underground wall to be installed at Xcel nuclear plant
Underground wall to be installed at Xcel nuclear plant 00:26

MONTICELLO, Minn. -- Xcel Energy says it is set to begin construction this weekend on an underground wall meant to impede interaction between river water and groundwater at its Monticello plant.

This comes nearly a year after a leak was discovered at the nuclear plant that allowed 400,000 gallons of water containing tritium into the groundwater beneath the plant.

Following the leak, Xcel has been working with the Nuclear Regulatory Commission, Minnesota Department of Health and Minnesota Pollution Control Agency to monitor groundwater in the area for tritium.

RELATED: What exactly is tritium? And when is it a health concern?

So far, no tritium has been detected in the Mississippi River, Xcel reports. The closest water sample to detect tritium is about 30 feet from the river and is far below Safe Drinking Water Act standards.

The 600-foot-long tunnel made out of interlocking metal sheets will extend about 40 feet deep and will be placed around 20 feet from the river.

Xcel Energy says constructing the barrier is another step it is taking to ensure that the small amount of tritium still present in the groundwater remains within the boundaries of the plant.

Construction work will primarily take place during daylight hours on typical working day but work may also take place on the weekend as well, the company says. The project s expected to last four to eight weeks.

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