The U.S. Department of Energy announced Wednesday that it plans to ship more than 6 tons of weapons-grade plutonium more than 1,400 miles from a national laboratory in South Carolina to a nuclear waste dump in Southern New Mexico when the facility — shut down two years ago by a radiation leak — reopens for waste storage, possibly by the year’s end.

Despite the costly leak at the Waste Isolation Pilot Plant near Carlsbad that broke the facility’s promise to “start clean, stay clean,” and concerns about transporting the hazardous material across the nation, federal officials say WIPP is crucial to national security — and the cheapest place to put the plutonium.

South Carolina is fining the Department of Energy $1 million for each day it fails to remove the plutonium from the Savannah River Site, following a missed deadline this year. The department already faces more than $88 million in fines from the state.

Billions of dollars have been funneled into a still-unfinished Mixed Oxide Fuel Fabrication Facility at the South Carolina lab where the waste was set to be processed, and new estimates say it could cost up to $30 billion more to complete the project. The plan for “dilution and disposal” of the plutonium at WIPP is estimated to cost $400 million annually.

The plutonium will be blended with an oxide by workers at the Savannah River Site to dilute its potency, then packed inside large storage containers before shipment to WIPP.

In April 2015, Gov. Susana Martinez urged Energy Secretary Ernest Moniz to consider bringing new nuclear waste to the Carlsbad dump, saying it would “broaden their economic base.”

But since the radiation leak in February 2014 forced the storage site to close, questions have been raised about the ability of the U.S. Energy Department, the New Mexico Environment Department and Los Alamos National Laboratory — which improperly packaged the drum that burst and contaminated WIPP — to safely manage nuclear waste.

Undersecretary for Nuclear Security Frank Klotz signed the decision on the plutonium plan Wednesday, saying WIPP has a “proven process” for storing this type of waste stream. It already has received 5 metric tons of surplus plutonium from the Rocky Flats Plant in Colorado and the Hanford Site in Washington.

He called the new plan a “path forward.”

Cleanup work at WIPP from the radiation leak began earlier this year. In mid-February, remediation workers were evacuated and underwent medical evaluations after poor air quality was reported in the underground facility. Work continued at the site, but two areas of the facility were blocked off due to poor ventilation.

“The tension between shipping waste and reopening WIPP, versus protecting workers’ safety, is a really important issue,” New Mexico Environment Secretary Ryan Flynn said in an interview Wednesday.

Prior to the leak two years ago, he said, WIPP workers didn’t perform emergency response drills — they watched safety videos. And old facilities weren’t maintained, he said, adding that such oversight led to a truck fire at WIPP in 2014, shortly before the radiation leak. After a vehicle washing station was removed to save money, oil built up on the vehicle, causing the fire.

The decision to ship plutonium from the Savannah River Site to WIPP came on the same day that the New Mexico Environment Department released a draft of its new consent order outlining waste cleanup requirements at Los Alamos.

Under the existing consent order, signed by the state, the Department of Energy and the lab in 2005, all nuclear waste was to be removed from lab property by December 2015. That deadline came and went with barrels of waste still stacked at lab sites, in part because of the WIPP shutdown. In January, the watchdog group Nuclear Watch New Mexico filed a notice with the state Environment Department of its intent to sue over the missed deadline.

But the new consent order doesn’t create new deadlines for waste removal at the lab.

“I still want the waste from Los Alamos to be prioritized — over anything,” Flynn said Wednesday. “That is the waste that is sitting in my backyard, that is sitting in the backyard of the people I am representing.”

But the lab and the state’s interests are likely to be pushed aside as the federal government focuses on other nuclear waste priorities.

The National Nuclear Security Administration has said its plan to dispose of the Savannah River Site plutonium will meet WIPP’s standards and that workers will be protected from airborne emissions. The agency also said “no latent cancer fatalities are expected in the general public along the transportation routes and in the transportation crews” as the plutonium is shipped from South Carolina to New Mexico.

Jay Coghlan, director of Nuclear Watch New Mexico, said the ventilation problems at WIPP are worrisome and need to be resolved before the plutonium is stored there. “We don’t think they can do it without compromising workers safety,” he said of the plutonium plan.

Plutonium is highly carcinogenic when it’s inhaled, he said.

Greg Mello, director of the Los Alamos Study Group, echoed Coghlan’s concerns, but said he is in favor of the plan overall.

“It’s simple, it’s cheap and I think this is real cleanup,” he said. “After decades of not really having a pathway for surplus plutonium, I think we have to bite the bullet.”

Once the plutonium is safety stored in WIPP’s underground salt repository, Mello said, it has little risk of overheating or leaking liquids, and it is likely to be safely contained.

The larger issue, he said, is what to do with the waste that continues to pile up from current nuclear weapons work as more than 7 tons of surplus plutonium in the U.S. awaits action.

Both U.S. senators from New Mexico weighed in on the issue Wednesday.

“If DOE moves forward with this plan, the state of New Mexico and Congress will need assurances that this proposal fully complies with WIPP’s disposal criteria and with the Land Withdrawal Act,” Sen. Tom Udall, D-N.M., said in a statement to The New Mexican.

Udall recently questioned Undersecretary Klotz about plans to restart plutonium pit production at Los Alamos. The senator’s office said Wednesday that some of Udall’s questions have yet to be answered.

Both he and Sen. Martin Heinrich, D-N.M., stressed the importance of safety.

“We have to go above and beyond to ensure the safety of our workers, communities, and the environment,” Heinrich said in a statement. But he said the value of WIPP to national security goals and to New Mexico’s economy “cannot be understated.”

Contact Rebecca Moss at 505-986-3011 or