HERMISTON -- Earlier this year, the company that runs Umatilla's chemical weapons incinerator investigated the plant and found haphazard planning and "a poorly designed leadership structure" had created "a constant state of . . . crisis management."

The February internal audit followed a string of mistakes that dramatically slowed the plant's work destroying rockets. The audit led the U.S. Centers for Disease Control and Prevention last month to call for improvements and another review of operations by year's end. It also troubled the U.S. Army, which stores weapons at Umatilla Chemical Depot near Hermiston.

"What I saw the first few months I believe to be significantly below what I wanted to see," said Don Barclay, the Army civilian who manages the project. "We had too many crises."

Officials responded by overhauling their planning and management, which Barclay said "significantly improved" the plant's efficiency.

But just as the pace improved, small explosions blew the work back off track. Since April 7, three rockets have burst into flames as a machine chopped them into pieces. Reinforced rooms contained the fires with little damage and no harm to people. Still, Oregon's Department of Environmental Quality suspended processing after the third blast, on May 18, while plant officials hunt for the cause. The $395 million incinerator remains shut down.

The fires have again clouded the future of Umatilla's incinerator, one of four sister factories destroying the aging U.S. stockpile of nerve agent and mustard gas. But Oregon's facility has had more rocket fires, and less success destroying weapons, than any.

Depot and DEQ officials were scheduled to meet today in Portland to review the investigations and plans for further studies, which could last for months. Oregon's DEQ might let the plant restart before all the new studies finish, said Sue Oliver, a specialist with the agency's Hermiston office. But "we've got to start with seeing what they're planning on doing" before deciding when processing can resume, she said.

The current shutdown joins several earlier delays that have put the plant well behind schedule. Rocket-processing lines have been quiet more than half the days since Sept. 8, when Umatilla processed its first warhead -- an event delayed for hours by an accidentally pressed "emergency stop" button.

So far, Umatilla has destroyed 14,530 of the 91,400 sarin-armed M55 rockets stored at the depot. In comparison, a sister plant in Pine Bluff, Ark., has destroyed more than 8,000 rockets since starting March 29. That averages to about 130 a day in Pine Bluff, about 55 a day at Umatilla.

"I expected to have twice as many rockets processed at this point as I do," Barclay said. "And there's a lot of reasons for that."

In the first months after the plant started, inadequate training, planning and management caused errors and delays. That includes a Sept. 14 accident in which two workers walked through the wrong door into "the Toxic Cubicle," a room that holds tanks of drained sarin. The workers were not wearing the full protective chemical suits needed for that room, but were not hurt.

On Dec. 1, two workers unbolted the wrong door on a system that filters plant air and let traces of sarin into the room where the worked. They also were underprotected but unhurt. Managers stopped processing for a 22-day "safety stand down" afterward.

"Any time there's an issue like that, yes, it's a concern," said Terry Tincher, an official with the CDC, which oversees safety for U.S. chemical weapons work. The CDC asked the plant to investigate those incidents after the December problem, Tincher said.

Barclay said he also wanted to address the mistakes and delays. He and officials from Washington Group, which contracts with the Army to run Umatilla and other incinerators, decided an internal audit would be most valued by plant workers.

The group's audit listed dozens of concerns, including a lack of a unified project schedule and leaders "struggling to establish a clear vision." There was a large work backlog, "little evidence of a true environmental compliance culture" and some safety concerns, including workers with limited protective gear using doors that should only be used by people in full chemical suits.

Overall, the managers and workers who spent years building the plant seem not to have adjusted to the new job of burning weapons -- or the safety risk that entailed, the report found. That likely played a role in incidents such as the Toxic Cubicle event, because workers often walked through that room before the plant started destroying weapons.

Barclay said managers are working to fix all 10 areas highlighted in the report. Many changes have already improved operations, he said, such as a new practice of planning work 16 weeks in advance. Barclay added that workers have more of "an appreciation for" dangers now. He said the audit "worked far beyond what I expected," that Washington Group now plans similar audits at its other chemical plants.

"A lot of work force retraining took place as a result of this," said Rick Kelley, Washington Group protocol manager for the Umatilla plant. "It's going to add safety to our employees. It's going to help us better serve our client."

Tincher said the investigation seemed thorough, but CDC has asked the Army for more details about some safety practices and a follow-up audit, focused on safety, in the next six months.

After the changes, workers regularly destroyed more rockets more quickly. In March, Washington Group won an Oregon Governor's Occupational Safety & Health award. In April, the Umatilla plant set a record for running U.S. chemical arms plants by destroying 563 rockets in one day.

The fires replaced that momentum with an Army-wide investigation of whether the 1960s-era rockets are growing less safe..

"These things are getting more and more unstable as time goes on," said Rodney Osgood, steward with International Union of Operating Engineers Local 701, which represents roughly 180 Umatilla incinerator workers. "Our concern is, how unstable is it?"

Osgood said more fires would not be a big problem if they only happen in the reinforced rooms where rockets are cut. But he worries more about a rocket catching fire elsewhere, especially in the "unpack room," where workers move rockets from storage pallets to automated conveyers.

The Army is also concerned, Barclay said, but has found no evidence yet that the rocket fires threaten workers or the public. Umatilla's fires all were contained in rooms where no people work. They did a few thousand dollars of damage to equipment, at most.

Investigators have not found a root cause for Umatilla's fires, but patterns point to the rockets as the culprit. The three recent fires ignited as a large blade made the first of three cuts through the M55's explosive propellant section, Barclay said. In each case, the propellant was from a lot made in October 1962.

A November fire at Umatilla happened during the final cut through the propellant. That propellant was made in 1960, Barclay said. Crews had blamed that fire on a problem with a spray nozzle that cools the blade, but are reconsidering in light of subsequent fires, he said.

All five of the Army's chemical weapons incinerators have had at least one rocket catch fire during the fifth or seventh cut, Barclay said. The Arkansas incinerator has had two fires in May that helped spur the Army-wide investigation. Arkansas regulators have not made that plant stop, and it is still processing weapons.

The Army's investigation has several parts, said an Army spokeswoman, Marilyn Daughdrill . Engineers have confirmed that the reinforced rooms where rockets are cut remain strong enough to withstand explosions. In coming weeks, workers will remove propellant from nine Umatilla rockets, and at least three Arkansas ones, for testing in New Jersey, she said. Scientists there will study how age is affecting the explosives and whether the October 1962 lot has special problems.

Meanwhile, engineers at Umatilla are changing the plant to reduce the chance a rocket will explode and to limit damage from fires. For instance, workers enhanced the fire-dousing "deluge system" before the May 18 fire, helping extinguish it in seconds.

Army officials and state regulators said studies may show that fires are a fact of life with aging rockets.

"I guess the conclusion might be that we're just going to have to live with sudden, low-order explosions," Oliver said. But the DEQ wants to be sure the plant has done everything it can to avoid the problem, she said.

Barclay said the plant could continue operating with occasional fires, though each would stop work for six to eight hours of investigation and cleanup. While that could put the plant further behind schedule, he said he worries about operating safely, not quickly.

"Am I disappointed" with the schedule? Barclay asked. "No, because no one's been hurt."

Andy Dworkin: 503-221-8239; andydworkin@news.oregonian.com