COLUMBIA — Nuclear watchdogs received a rare tour of a partially built plutonium recycling facility at South Carolina’s federal nuclear site this week.

Speaking at the Statehouse Wednesday following their visit the day before, anti-nuclear and environmental groups claimed efforts to repurpose a mothballed nuclear fuel plant on the site into a facility to replace the plutonium cores of bombs, known as pits, in the country’s nuclear arsenal amount to a drain on taxpayer dollars.