PORT GIBSON — An unknown amount of radioactive water was released accidentally into the Mississippi River late last week at the Grand Gulf Nuclear Station.

The Nuclear Regulatory Commission is investigating the incident, but suggests the release poses no public health hazard.

Entergy Nuclear, which operates Grand Gulf, filed a report with the NRC explaining that crews located standing water at the plant last week after the area experienced heavy rains.

Water was found Thursday at the Unit 2 turbine building — which is an abandoned, partially constructed building — and began pumping the water into the river.

An alarm apparently alerted workers to the presence of tritium, a byproduct of the nuclear reactor processes. The pumps were turned off stopping the flow. Investigators are not certain why tritium was in the storm water or how it got there.

“Although the concentrations of tritium exceeded EPA drinking water limits, the release should not represent a hazard to public health because of its dilution in the river,” said Lara Uselding, public affairs officer with the U.S. Nuclear Regulatory Commission, Region IV.

Tritium has several uses, including being a component in triggering mechanisms on thermonuclear weapons systems. The substance is often used in conjunction with phosphor material to create permanent illumination for items such as wristwatch dials and night-sights for firearms.

Information from the United States Environmental Protection Agency suggests exposure to tritium increases the risk of developing cancer, because tritium emits low-energy radiation and is processed through the human body quickly, it is considered one of the least dangerous radionuclides.