Single-shell tank at Hanford found to be leaking waste

Tri-City HeraldFebruary 16, 2013 

An underground single-shell tank at Hanford is leaking up to 300 gallons of radioactive waste a year, Washington Gov. Jay Inslee said Friday.

"I am alarmed and deeply concerned by this news," Inslee said in a press conference. "This is a problem we thought was under control."

Tank T-111 is the first of Hanford's 149 single-shell tanks to apparently leak since pumpable liquids were removed from the last of those tanks in 2004. As many as 67 of the tanks are believed to have leaked in the past.

The tanks contain a mix of high-level radioactive and hazardous chemical waste left from chemically processing fuel irradiated at Hanford reactors to remove plutonium for the nation's nuclear weapons program.

"Washington state has a zero tolerance policy on radioactive leaks," the governor said. "We will not tolerate any leaks of this material into our environment."

The state is willing to take legal action if needed, but that will not be necessary if Congress does its job and meets the nation's legal and moral obligation to clean up Hanford, he said.

The Department of Energy said Friday that liquid levels are decreasing in Hanford Tank T-111 at an estimated rate of 150 to 300 gallons a year, or a half gallon to a gallon a day. Although the most likely cause is a leak, DOE Hanford officials have not confirmed that. DOE said it still is determining the specific cause.

There is no immediate risk to the public, Inslee said. An estimated 1 million gallons of radioactive waste have leaked from Hanford's underground tanks in the past.

Some of that contamination has reached the groundwater in central Hanford, but any movement of the contaminated groundwater toward the Columbia River is slow, according to DOE and the state, which is a Hanford regulator.

But the state is concerned about not just Tank T-111, but the condition of other single-shell tanks used to hold waste from the past production of plutonium.

Tank T-111 was one of 64 tanks built in 1943 and 1944.

"This is one leaker, but we have got a bunch of old tanks out there," Inslee said.

A legacy of leaks

Evidence suggests this leak at Tank T-111 may have been going on for several years, Inslee said.

Previous leaks were identified in 1979 and again in 1994, with an estimated loss of less than 1,000 gallons of waste, said Cheryl Whalen, cleanup section manager for the Washington State Department of Ecology.

In 1995 pumpable liquids were removed, but about 38,000 gallons of liquid remained among the solids in the tank. The tank has a 530,000 gallon capacity and 447,000 gallons of waste remained. DOE described the remaining sludge, a mixture of solids and liquids, as having a mud-like consistency.

Last year an assessment of routine measurements in Hanford's single-shell tanks found that the level of waste might be slowly rising in 52 tanks. DOE has been inserting video cameras into the enclosed underground tanks to inspect for potential sources of water intrusion, particularly from rainfall and snow melt.

Those inspections helped find the suspected leak in Tank T-111.

By January, three tanks had been inspected. DOE found a slow drip into one of the tanks from a concrete drain pit that may be adding up to 200 gallons of water a year. Underground concrete pits covered with removable concrete blocks were used when waste was being moved into or among tanks when Hanford still was producing plutonium.

Tank T-111 was the fourth tank inspected, and possible evidence was found that water had leaked into the tank in the past. Water leaking into the tank may have masked the liquid waste leaking out into the soil, Inslee said.

In November and December, the waste level in the tank fell below the normal range.

Measuring the level of waste in tanks can be difficult, because they are so large that a change of even a couple of hundred gallons of waste can be difficult to detect.

The levels can fluctuate as air pockets build up or dissipate. And the top of the waste can have peaks and valleys, which can make measurements vary.

DOE is working to empty the single-shell tanks of the sludge and salt cake that remains. The waste is being transferred into newer double-shell tanks for storage until the vitrification plant starts operating to glassify the waste for disposal. The plant is required to begin operating in 2019.

DOE believes it has emptied 10 of 149 single-shell tanks to regulatory standards. Work is concentrated now on the C Tank Farm, where DOE must meet a court-enforced consent decree to have all 16 tanks emptied by September 2014. No work has been done to empty solids from any of the 16 tanks in the group called T Tank Farm, which includes Tank T-111.

Work to design, fabricate and install systems to remove waste from a tank can take more than a year.

Multiple challenges

Energy Secretary Steven Chu called Inslee on Friday about Tank T-111. They plan to meet next week about the response.

The state needs to send a clear message to Congress that even in this time of tight federal budgets, the state of Washington will not let the federal government waver in the commitment to clean up Hanford, Inslee said.

"With an active leak of high-level waste into the environment, money cannot be allowed to be an excuse for inaction," he said. "The proposed sequestration we are facing could not come at a worse time."

Earlier this week, House Appropriations Committee Democrats said automatic federal budget cuts known as "sequestration" could lead to a slowdown in emptying Hanford's single-shell tanks after March 1 and six weeks of unpaid leave for 1,000 Hanford workers.

Hanford has multiple challenges, including the vitrification plant and its double-shell tank farms, Inslee said. DOE has said technical issues that must be resolved at the vit plant have put legal deadlines at risk of not being met and could increase costs.

In October, DOE confirmed that it had found its first leak from the inner shell of an underground double-shell tank.

Inslee said at the end of January that more double-shell tanks must be built. More storage space is needed -- not only because of the double-shell tank leak, but also because tanks will be needed to prepare waste for treatment at the vitrification plant.

The leak announced Friday adds to the storage need, he said.

"We are not going to allow ourselves to be trapped into a dead end of arguing about prioritizing these challenges," he said. "We will not allow the federal government to play the single-shell problem off against the vitrification plant. Both need to proceed on an accelerated schedule."

The Tank T-111 leak is a wakeup call to the federal government to redouble its Hanford cleanup efforts, he said.

"I have met with my legal team and asked them to develop new legal options to enforce the U.S Department of Energy's current obligations to clean up Hanford," Bob Ferguson, the new Washington attorney general, said in a statement.

More video inspections

DOE will continue to monitor the waste in Tank T-111. Monitoring wells in the T Tank Farm have not identified significant changes in concentrations of chemicals or radionuclides in the soil, according to DOE.

Plans made before the issue with Tank T-111 was discovered call for video inspections of eight more single-shell tanks this year because of concerns about water getting into the tanks. DOE also does routine monitoring for leaks from tanks.

DOE has taken steps to prevent tank waste that has leaked in central Hanford from reaching the Columbia River.

The largest groundwater treatment system in the DOE environmental cleanup complex started treating contaminated groundwater in central Hanford last year, removing several radioactive and chemical contaminants. The groundwater there is contaminated by chemical processing facilities and tank leaks.

Contaminated water is pumped out of the ground by a system of wells that can be expanded or moved if conditions change, such as if new sources of contamination are found.

In addition, DOE finished installing a 70,000-square-foot cap of dirt and plastic over part of the T Tank Farm in 2008.

It's meant to stop rain and snow melt from spreading contamination deeper into the soil, at least until cleanup decisions are made for contaminated soil there.

The cap's main purpose is to stop the spread of contamination from Tank T-106, which is believed to have previously leaked 115,000 gallons of waste into the soil.

However, the cap also extends over a portion of Tank T-111.

Tri-City Herald is pleased to provide this opportunity to share information, experiences and observations about what's in the news. Some of the comments may be reprinted elsewhere in the site or in the newspaper. We encourage lively, open debate on the issues of the day, and ask that you refrain from profanity, hate speech, personal comments and remarks that are off point. Thank you for taking the time to offer your thoughts.

Commenting FAQs | Terms of Service