The Department of Energy will delay calculating a new cost and schedule for Hanford's huge vitrification plant until more technical issues that could affect the safe and efficient operation of the plant are addressed.

The announcement came Tuesday from DOE headquarters as DOE released a report on a Differing Professional Opinion filed by a Hanford DOE scientist that concluded his concerns about erosion and corrosion in the plant have merit.

DOE already is preparing for a large scale test to make sure waste in the plant's tanks will remain adequately mixed. Now, testing on erosion and corrosion will be added to that project, said David Huizenga, DOE's senior adviser for the Office of Environmental Management in a media conference call after congressional leaders were briefed Tuesday.

The cost of testing has not been figured, but it will cost tens of million of dollars and will take more than a year to complete, he said.

"We're trying to address technical issues head on and realistically," Huizenga said.

The plant is being built to turn up to 56 million gallons of radioactive waste into a stable glass form for disposal. The waste, now held in underground tanks, is left from past production of plutonium for the nation's nuclear weapons program.

Until the technical path forward is clear, DOE will not develop a new baseline -- a total cost report and schedule for completing the plant.

The plant is legally required to start operating in 2019 and is projected to cost $12.2 billion, but DOE will not be able to finish it by then and at that price.

DOE had instructed its contractor Bechtel National in February to propose a new cost and schedule for the vitrification plant, which was due in August.

But with technical questions to be addressed for parts of the plant that will handle large quantities of high-level radioactive waste, Bechtel will proceed only with a cost and schedule revision for the plant's Low Level Waste Facility, the Analytical Laboratory and about 20 support facilities.

When testing is finished, it then can address additional cost and schedule information for the vit plant's High Level Waste Facility and Pretreatment Facility.

Those two buildings have areas called "black cells" that will be too radioactively hot for workers to safely enter after the plant begins operating for maintenance or to make repairs.

Construction at those facilities already has been ramped down and no further layoffs are anticipated because of Tuesday's announcement. From fall 2011 to this spring, Bechtel laid off about 550 construction workers and it also announced this spring that it would cut another 200 to 300 nonconstruction positions by the end of the year.

The project still will require $690 million annually, including money to address the technical issues, Huizenga said.

However, DOE will need to make the case to Congress that it should receive that budget level with construction slowed on key facilities and no final cost and schedule.

It's been just two years since DOE agreed to a court-enforced consent decree for new deadlines for the plant, said Rep. Doc Hastings, R-Wash. The technical issues are not new, making it especially frustrating that the project has reached the point at which DOE is stopping work at two of the plant's facilities, he said.

"It's unacceptable that after all this time -- and despite additional funding beyond $690 million in recent years -- there is no real plan or budget in place to resolve these issues," he said. "Congress will require these details, as well as updates on the total project cost and schedule."

Most importantly, construction on the Pretreatment Facility and High Level Waste Facility must not be stopped indefinitely, he said.

DOE will need to enter talks with the state of Washington, a regulator on the project, to explain issues and negotiate a new timetable, Huizenga said. The state also places a high priority on finishing the plant, which will allow waste to be removed from aging underground tanks, protecting the ground water and the Columbia River.

A new building is being built at Washington State University Tri-Cities for large scale testing of mixing at the plant. High-level radioactive waste must be kept well mixed within the vit plant's black cell tanks to keep plutonium particles from settling out and building up, creating a small chance of a criticality.

In addition, concerns have been raised about whether metal pipes and vessels in black cells will be damaged by decades of mixing particles and moving them through pipes.

Don Alexander, a DOE scientist, raised questions regarding erosion and corrosion in piping and tanks in black cells within the plant in September in a Difference of Professional Opinion report, disagreeing with scientific opinion accepted by DOE.

It was the third set of issues he'd raised in an ongoing Difference of Professional Opinion.

DOE addressed his concerns with a panel of technical experts that concluded his concerns are legitimate, and now DOE is planning testing that will be done in conjunction with already planned mixing testing to resolve them, Huizenga said.

"I think this demonstrates if people raise issues, we are willing to make tough decisions to address them," Huizenga said.

The Defense Nuclear Facilities Safety Board and the DOE Office of Health, Safety and Security have questioned whether workers feel free to raise technical issues that could affect future safe operations at the plant and whether those issues are addressed.

Among the recommendations in the report on the Differing Professional Opinion are performing more analysis, performing more testing, using conservative measures to reduce uncertainty and possibly considering changes to the materials used or construction processes used.

The panel also recommends a comprehensive approach to monitoring potential damage.

The testing is intended to give additional confidence that the plant can operate for the full 40 years planned, Huizenga said. By acknowledging issues now, the plant will not end up with unanticipated costs and maintenance issues in the future, he said.

"We're all, frankly, disappointed that this waste stream is so complicated and it's causing us these kind of issues and these kind of problems," Huizenga said.

-- Annette Cary: 582-1533; acary@tricityherald.com