Workers inspect a valve at the "C" tank farm during a media tour of the Hanford Nuclear Reservation in July 2014 near Richland, Wash. (Ted S. Warren/AP)

A nearly completed government facility intended to treat the radioactive byproducts of nuclear weapons production is riddled with design flaws that could put the entire operation at risk of failure, according to a leaked internal report.

A technical review of the treatment plant on the grounds of the former Hanford nuclear site identified hundreds of “design vulnerabilities” and other weaknesses, some serious enough to lead to spills of radioactive material.

The draft report is the latest in a series of blows to the clean-up effort at Hanford, the once-secret government reservation in eastern Washington state where much of the nation’s plutonium stockpile originated. Engineers have struggled for years to come up with a safe method for disposing of Hanford’s millions of gallons of high-level radioactive waste, much of which is stored in leaky underground tanks.

Energy Department officials have spent tens of millions of dollars to design and construct the site’s Low-Activity Waste Facility, intended to convert some of Hanford’s radioactive waste into a glasslike product that could be stored underground in the future. Although the plant is regarded as one of Hanford’s most successful projects, the internal report identified serious flaws in its design.

The 2014 report is marked “predecisional draft,” and no final version has been publicly released. The document was leaked to a nonprofit watchdog group, Hanford Challenge, which provided a copy to The Washington Post.

“Unless resolved in a timely manner, these vulnerabilities are expected to result in unacceptable risk to the overall project mission,” stated the report, prepared by a team of scientific and technical experts under Energy Department oversight.

The report cites fundamental lapses in multiple areas, ranging from ventilation of waste-
handling areas to the plant’s backup electricity supply. The reviewers found numerous problems with the system that “vitrifies” waste by turning it into glass, noting that the engineers miscalculated how long it would take for the radioactive end-product to cool. “When a container full of molten glass is lifted, there is a chance that the container lifting flange will fail because it has not cooled enough to regain its strength,” the document states.

An Energy Department spokesman said that the report was a “very early draft” that contained a number of factual inaccuracies.

“The Department is committed to designing, building and safely operating” the waste facility, spokeswoman Yvonne Levardi said. “While the draft report has not been finalized, it does not identify any unknown major technical issues with the Low Activity Waste Facility.”

Hanford Challenge Director Tom Carpenter called the report “alarming,” suggesting a “safety-last culture” at the clean-up site.

“This plant is so riddled with design . . . nuclear safety and worker health threats that it is hard to see how this plant could ever open without very significant and expensive rework,” Carpenter said.

He said the document was released by a Hanford engineer who was afraid to go public for fear of losing his job. Carpenter released a statement in which the unidentified engineer said he had grown frustrated over the government’s failure to release the report.

“Some of the issues, if not resolved, will result in millions of dollars of cost to the tax payer, and could possibly result in injuries to the future workers,” the engineer said in the statement. “This is simply unacceptable.”

Robert Alvarez, a former senior Energy Department official during the Clinton administration, said the problems documented in the report reflect the unique challenges involved in the Hanford cleanup, which Alvarez described as the “largest, riskiest and most expensive nuclear project undertaken by the United States” and perhaps the world.

“[The Energy Department] has proven to be incapable of managing a project of this magnitude and importance,” Alvarez said. “The agency has shown a long-standing intolerance for whistleblowers while conducting faith-based management of its contractors regardless of poor performance. This has bred a culture in which no safety misdeed goes unrewarded.”