The U.S. Department of Energy on Friday contested more than $54 million in fines, the largest penalty levied by New Mexico for numerous violations that resulted in the indefinite closure of the nation's only underground nuclear waste repository.

The Energy Department and the contractors paid to operate the Waste Isolation Pilot Plant and Los Alamos National Laboratory said that they want a hearing on the matter, according to a statement.

Federal officials described the penalty as "capricious" and want it to be either reduced or forgiven. But the Energy Department also expressed a desire for more hearings about how to address operational issues at both facilities.

"We look forward to addressing the underlying causes that led to the compliance orders and to developing a positive path forward for the re-opening of WIPP and the resumption of transuranic waste operations at LANL," the Energy Department said in its written statement.

Discussions of a settlement have been ongoing since the violations were disclosed last month, New Mexico Environment Department spokesman Jim Winchester said.

"The parties will continue to engage in settlement discussions as the legal process moves forward," Winchester said in a statement. "However, we will not agree to back down on any of the problematic issues we identified in the compliance orders."

The state Environment Department delivered a pair of compliance orders to Energy Secretary Ernest Moniz on Dec. 6. In the orders, the state alleges more than 30 violations took place at the Waste Isolation Pilot Plant in southeastern New Mexico and the Los Alamos National Laboratory.

On. Feb. 5, a truck hauling salt at the nuclear dump caught fire. Nine days later, a canister of waste from Los Alamos leaked in one of the nuclear dump's storage rooms. More than 20 workers were contaminated, and the facility was forced to close, putting in jeopardy efforts around the nation to clean up tons of Cold War-era waste.

The state accuses Los Alamos of mixing incompatible waste, treating hazardous waste without a permit and failing to notify regulators about changes in the way waste was being handled.