Fish kill in Mississippi River blamed on Monticello nuclear plant shutdown

The shutdown of Xcel Power’s nuclear energy plant in Monticello to repair a leak of mildly radioactive water precipitated some collateral environmental harm: a fish kill within the Mississippi River.

Xcel Power reported that 230 fish died from thermal shock, not the tritium that has seeped into groundwater. The plant makes use of river water for cooling, after which sends warmed water again to the Mississippi. Because the plant powered down and the stream of heat water was reduce off, the sudden change in temperature proved deadly for bass, channel catfish, carp and sucker fish.

Pat Rivers, the deputy director of fish and wildlife for the Minnesota Division of Pure Sources, stated the occasion was “a reasonably small fish kill in relative phrases, however it’s nonetheless unlucky.”

Theo Keith, a spokesman for Xcel, wrote in an e mail that the utility tries to keep away from shutdowns “in winter months the place temperature variations are biggest.” He stated the utility powered down the plant slowly to attempt to reduce the impression.

The radioactive tritium that beforehand leaked on the plant has not reached the river, in response to a joint assertion from the Minnesota Air pollution Management Company and DNR.

Xcel and state companies first reported on March 16 that 400,000 gallons of tritiated water had seeped into the groundwater beneath the Monticello plant, and {that a} short-term repair had been put in place. Final week, Xcel stated its patch had failed, so it was going to close down the plant instantly for a restore, quite than ready for a deliberate outage subsequent month.

Tritium is a radioactive type of hydrogen that happens naturally and as a byproduct of nuclear energy era. It would not put up a well being threat except ingested, and state companies have repeatedly stated the tritium has not reached any consuming water sources.

Keith wrote that the leak has been completely mounted, and that the plant would start producing energy once more within the subsequent week, earlier than powering down once more April 15 for refueling.

There have been far bigger fish kills in Minnesota — final summer season, 2,500 lifeless fish, largely brown trout, have been present in a creek within the southeastern a part of the state. The state later decided that manure and pesticide runoff have been the most definitely causes of that die-off.

Rivers stated that hundreds of fish may also die in winter kills, when thick snow covers the ice on lakes and blocks daylight to the aquatic vegetation beneath. That stops photosynthesis, slicing off the out there oxygen.