US LaCrosseSolutions, a subsidiary of nuclear waste disposal company EnergySolutions, announced on 12 March that it had detected elevated levels of tritium in a monitoring well near a former reactor building in Genoa, Wisconsin. Dairyland, which operated the 50MWe La Crosse Boiling Water Reactor from 1967 to 1987, transferred the site licence to LaCrosseSolutions in 2016 to complete decommissioning process, which was expected to be completed later this year at the cost of about $85m.
According to EnergySolutions spokesman Mark Walker, a reading of 24,200 picocuries per litre was recorded on 14 February in a monitoring well 25 feet below ground. Although the measurement was below the Environmental Protection Agency’s drinking water limit of 25,000 picocuries per litre, EnergySolutions notified the Wisconsin Department of Natural Resources and the US Nuclear Regulatory Commission (NRC). Walker said off-site wells had not been tested because the contamination appears to be contained in shallow water on site. Environmental consulting firm Haley & Aldrich has been contracted to assist in further testing and to develop a groundwater monitoring plan.
LaCrosseSolutions stopped dismantling the containment tower while inspectors investigate the cause of the leak, but Walker said other decommissioning activities are continuing. The reactor vessel was removed in 2007, and in 2012 the spent fuel rods were transferred to dry storage casks. Under the decommissioning agreement, LaCrosseSolutions is to remove everything down to three feet below ground.