After a truck fire and a leaking drum of radioactive waste shut down the nation’s only underground nuclear waste facility near Carlsbad in February 2014, the Department of Energy said that by March 2016, it could cleanup and safely reopen the critical site.

The agency knew it had only a 1 percent chance of meeting that deadline, according to an audit released this week by the Government Accountability Office, an investigating arm of Congress.

In 2015, the agency admitted it couldn’t safely reopen the Waste Isolation Pilot Plant, even for limited operations, until at least December 2016 — and at a higher cost. Now auditors say even the revised cost estimate was flawed. The agency “did not follow all best practices for cost and schedule estimates,” federal auditors found, including having an independent analyst review them.

The report says the Energy Department also admitted in May 2015 that the pressure to meet the March 2016 deadline “contributed to poor safety practices in WIPP recovery efforts.”

The result of missteps in the process of reopening the facility, according to auditors, was a nine-month delay and a price tag $64 million higher than the original cleanup estimate. The Energy Department initially estimated it would cost $242 million to restore WIPP for limited waste disposal and an additional $77 million to $309 million to install a new ventilation system critical to providing clean air to workers. The delays led to an additional $61.4 million in operating costs at WIPP, and the cost to prepare the facility for limited activity went up another $2 million.

The Energy Department now says it is 80 percent confident that it will meet the December 2016 deadline to reopen on a limited basis.

But Don Hancock, a nuclear waste expert with the nonprofit Southwest Research and Information Center, is skeptical. He thinks it could take several million dollars more and a few more years to fully reopen WIPP.

“DOE was overly optimistic about scheduling and overly optimistic about costs,” Hancock said. “Unfortunately, DOE continues to not learn from its past. This is not unique to WIPP.”

GAO auditors agreed with Hancock’s assessment. “DOE has a history of exceeding its cost and schedule estimates and then creating new baselines,” they wrote in the report.

The department had to move back its deadline and revise costs for the WIPP recovery because it failed to take into account contingencies for numerous delays, like a piece of ventilator equipment that arrived at the site damaged and had to be sent back to the manufacturer, the auditors said.

In another issue, auditors found that the Energy Department didn’t consistently define the airflow and life expectancy of a critical ventilator system for contractors before the firms proposed alternatives for the agency to consider. That oversight makes it unclear whether the new ventilation system will meet the facility’s needs, according the report.

Fixing the problems at WIPP, a facility located in salt caverns more than 2,000 feet underground, with containers of radioactive waste stacked inside rooms, isn’t simple or cheap.

But Hancock said he thinks a rush to reopen the waste site by the original deadline and a desire to keep Congress happy with a realistic price tag and timeline led the Energy Department to fudge estimates. “Sometimes not following best practices is intentional,” Hancock said.

Carlsbad Mayor Dale Janway said the Energy Department has already admitted to many of the issues raised in the report.

“We support all efforts, including this report by the GAO, in making sure that the WIPP recovery effort is handled safely and in a manner that is fiscally responsible to the public,” Janway said.

Hancock thinks the Energy Department is still underestimating costs and doesn’t think WIPP will reopen by December. “The facility is not close to being ready to reopen and operate in a safe manner,” he said.

Part of the problem, Hancock said, is that the two accidents that shut WIPP down in the first place were never supposed to happen.

“So,” he said, “they are figuring out some of this as they go along.”

Contact Staci Matlock at 505-986-3055 or Follow her on Twitter @StaciMatlock.