Start of the large-scale pre-treatment of radioactive waste from Hanford

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Hanford is about to begin its first large-scale pre-treatment of the millions of gallons of radioactive waste that has been stored at the site for decades.

In about two months it could be up and running 24/7, Prepare waste to be directed to $ 17 billion vitrification facility to turn it into a sturdy glass shape for disposal.

Hanford officials say this will be a historic moment.

“It’s pretty exciting to be about to begin the first large-scale tank waste treatment at the Hanford site,” said John Eschenberg, president of Hanford’s tank waste contractor Washington River Protection Solution.

The Department of Energy announced on Tuesday that the construction and readiness assessment of the tank-side cesium removal would take place. or TSCR, the Hanford system was complete.

“What a lot of people don’t realize is that starting tank waste treatment actually begins with the start of TSCR operations. Therefore, in just a few months, we will be treating waste on an industrial scale for the first time in the history of the site, ”said Brian Vance, manager of DOE Hanford.

The system, which was placed next to an underground Hanford waste storage tank, was developed over three years as a workaround for the pre-treatment facility, which is 12 stories high and covers an area larger than a soccer field in the glazing facility.

The pre-treatment facility was designed to separate waste into low-level and high-level waste streams for treatment, but construction of the building was suspended after potential technical problems related to high-level waste were identified in 2012.

The DOE changed course and decided to start low-level radioactive waste treatment first and postpone high-level radioactive waste treatment for more than a decade.

It estimates that about 90% of the waste could be treated in underground tanks and disposed of as low activity waste in a lined landfill in Hanford.

the Hanford Nuclear Reserve adjacent to the Tri-Cities in East Washington 56 million gallons of tank garbage left over from WWII and the Cold War to produce about two-thirds of the country’s plutonium for its nuclear weapons program.

The current concern is that some of the underground storage tanks are prone to leakage.

How waste is pretreated

“Hanford tank waste management is one of the most important elements of the overall cleanup, and the TSCR system is a critical piece of the puzzle,” said David Reeploeg, executive director of Hanford Communities and vice president of federal programs for the Tri-City Development Council.

“We are pleased to see further progress being made on the path to tank waste treatment,” he said.

TSKR.png
A bird’s eye view of the process housing of the tank-side cesium removal system in the tank farm of a nuclear reserve in Hanford. The construction and readiness assessments have been completed.

TSCR can take the liquid portion of Hanford waste – the waste also includes sludge and salt cake – and separate highly radioactive components from it.

Low-activity radioactive waste is primarily liquid, but suspended, undissolved solids and radioactive cesium dissolved in the liquids are referred to as high-level radioactive waste and must be removed if the waste is treated as low-level waste.

The system filters the liquid to remove solids and uses an ion exchange system to remove cesium.

The system fits into three enclosures near a waste tank, the largest of which is the size of a land-to-sea shipping container.

Eschenberg has no doubts that the small system will work.

“We are all very enthusiastic about the technology and the simplicity of the system,” he said.

He led work to commission a near-identical system to prepare radioactive waste for vitrification at DOE’s Savannah River, SC site.

And simplified ion exchange systems have been used in the purification of contaminated water for a decade after the nuclear disaster in Fukushima, Japan.

Hanford waste is more complex and contains a lot of radioactive and chemical contaminants from various plutonium production methods that have been used at the Hanford site for decades.

Batches of tank waste must be extensively examined, sampled and characterized to ensure that they are compatible with the vitrification treatment in the vitrification facility, Eschenberg said.

Treatment start

TSCR is expected to start preparing waste for vitrification in January.

Although operations could start a few weeks early, the start of new projects at Hanford is often postponed until after the holiday season to ensure workers are available and not distracted.

This year adds the added stress of a controversial COVID-19 vaccine mandate that requires federal employees to be fully vaccinated or a waiver approved. The deadline for fulfilling the mandate is expected to be extended from December 8th.

The vitrification facility is not expected to begin vitrifying low-level radioactive waste until the end of 2023.

But work on processing waste with TSCR for feeding the plant starts almost two years earlier.

Hanford’s goal is to store one of its 27 double-shell, underground tanks with 1 million gallons of pre-treated waste for the vitrification plant when the plant comes on stream.

Since the vitrification plant can vitrify waste faster than TSCR can process it for the plant, the stored waste helps with the start and continuation of the treatment process.

The 1 million gallons and waste that TSCR will continue to pre-treat after the vitrification facility is commissioned will keep the facility for the first four years of operation for low-activity vitrification waste.

TSCR will be evaluated in the first year of operation to help determine whether to add another TSCR at Hanford terminals or develop a larger treatment capacity.

The future of the giant pre-treatment facility in Hanford is part of negotiations between Washington State and the federal government on the future of waste treatment at Hanford, including pre-treatment of high-level radioactive tank waste.

Supervisors

The Nuclear Defense Security Council, in a weekly report from its inspectors in October, expressed concern about TSCR, which it believed was an important issue.

Hanford workers discovered that the threaded connection that was used to discharge waste into the ion exchange system had seized after friction damaged the thread and possibly compromised the connection.

The security board said it was a possible risk of leakage from radioactive waste.

However, Eschenberg said the contractor found that the connection problem was caused by workers putting the feed line up and down several times during training in preparation for operations.

A re-evaluation of the design and materials used in the compound did not reveal any problems, he said. When the waste feed line is hooked up to the ion exchange system, the focus is on proper assembly techniques, he said.

The Washington State Department of Ecology, a Hanford tank waste regulator, has reviewed TSCR documents and inspected TSCR on-site and determined that it meets state permit requirements.

“We look forward to the tank-side cesium removal system becoming an important part of the successful commissioning and operation of the low-activity waste treatment facility at Hanford,” said the agency in a statement.

Washington River Protection Solutions was able to complete TSCR on schedule as its employees did much of the work during the COVID-19 pandemic.

The terminal contractor designed the system and managed the construction and installation through subcontractors AVENTech, Atkins Nuclear Secured, Fowler General Construction and Apollo.

“Completing the TSCR building this year was a top priority for the Department of Energy’s environmental management office,” said Vance.

“For the first time we will be able to treat a significant portion of Hanford’s tank waste. This is an exciting and historic time, ”he said.

This story was originally published November 16, 2021 12:42 p.m.

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Senior writer Annette Cary covers Hanford, Energy, Environment, Science, and Health for the Tri-City Herald. She has been a news reporter in the Pacific Northwest for more than 30 years.


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