By Maegan Murray, ���سԹ�

RICHLAND, Wash. – After seeing initial success in developing an ultra high-performance grout to potentially encapsulate solid secondary waste at the Hanford Site, (WRPS) is providing a Washington State University Tri-Cities professor and his research team with more than $300,000 to further the research.

The ���سԹ� team, led by civil engineering professor Srinivas Allena, is developing what is known as an ultra high-performance cementitious composite grout. The team’s final formulation will use industrial byproducts such as coal ash and steel slag that have the potential to reduce costs compared to commercially available and prepackaged high-performance grouts, while reducing the impact on the environment. The solid secondary waste it would encapsulate could include items such as used or broken equipment, contaminated tools and equipment that require stabilization and encapsulation prior to disposal.

WRPS is the ’s Tank Operations contractor responsible for managing Hanford’s 56 million gallons of highly radioactive waste and preparing it for delivery to the . The organization provided the WSU team last year with more than $140,000 to develop a grout to encapsulate solid secondary wastes from tank farms and future Waste Treatment Plant operations, and the team came up with several formulations. Now, the WSU team is further optimizing those formulations to produce a cost-effective and sustainable grout formulation.

The end formulation has to be able to handle large physical stresses while proving resistant to rapid freezing and thawing cycles, low porosity and long-term durability.

For one of their formulations, Allena and his team showed success in replacing a typical ingredient in commercially available encapsulation grouts, known as silica fume – a byproduct from the silicon industry – with a substance known as fly ash, which is a remnant product from burning coal in thermal power plants. The fly ash, often a waste product, would serve as a cheaper and locally sourceable option, in addition to reducing the amount of coal-based ash that is sent to landfills or returned to coal mines for disposal.

For another formulation, the team plans to replace fine sand typically used in encapsulation grouts with locally-sourced, larger-particle sand, which would not require a sieving process. The removal of the sieving process saves on cost and previous results have shown that the large sand-containing formulation holds the needed strength and low porosity required for an encapsulation grout.

The technique, though promising, is in the proof-of-concept phase. Any future use at Hanford would still need to meet disposal criteria for any given waste stream and undergo regulatory approval and any applicable permitting processes.

“We’re repurposing waste products and also reducing the cost while ensuring and enhancing the durability properties required for an encapsulation grout,” Allena said. “Our initial testing has shown good results.”

The team also plans to partially replace regular cement with blast furnace slag, which is a byproduct powder from steel industries. Using slag would help reduce greenhouse gas emissions.

“Cement industries cause approximately 7 to 11 percent of greenhouse gas emissions worldwide,” Allena said. “Cement is made from the burning of limestone and leads to the release of a lot of carbon dioxide. Reducing the demand on cement by using slag will therefore reduce cement production and the associated greenhouse gas emissions.”

Allena said if they are successful with their end formulation, their grout has the potential to be used in a variety of applications, such as bridge construction, and has large commercial potential.

 

Media contacts:

Srinivas Allena, ���سԹ� engineering faculty, 509-372-7161, srinivas.allena@wsu.edu

Jeffrey Dennison, ���سԹ� director of marketing and communication, 509-372-7319, Jeffrey.dennison@wsu.edu

Maegan Murray, ���سԹ� public relations specialist, 509-372-7333, maegan_murray@wsu.edu

By Maegan Murray, ���سԹ�

RICHLAND, Wash. – Two teams at Washington State University Tri-Cities have partnered with Washington River Protection Solutions to procure and program an autonomous vehicle and develop a form of ultra high-performance concrete to help protect workers in radioactive areas at the Hanford Site and safely immobilize solid secondary wastes.

WRPS is the U.S. Department of Energy’s Tank Operations contractor responsible for managing Hanford’s 56 million gallons of highly radioactive waste and preparing it for delivery to the Waste Treatment Plant on the site. The partnership for the projects will provide WRPS with customized technology to fit their needs, in addition to further improving the safety capabilities of its employees and environmental impact stemming from the tank farms at the Hanford Site.

Robotics to analyze radioactive vapors

WRPS provided a WSU team with an initial contract to procure and program an autonomous vehicle that would be used for measuring vapors, or chemical gases, within the tank farms.

The WSU team consists of Akram Hossain, vice chancellor for research, graduate studies and external programs; Scott Hudson, professor of electrical engineering; John Miller, associate professor of computer science; and Changki Mo, associate professor of mechanical engineering.

The team plans to purchase a pre-fabricated, compact and programmable vehicle, which has the capacity to hold 40-50 pounds of equipment. The team will then eventually outfit, customize and program the vehicle for its desired purpose within the tank farms. The vehicle must be able to follow a defined path, dock itself to charge its battery, withstand long-term use, be able to run autonomously, as well as allow manual override operations.

“This vehicle will be going into areas, minimizing personnel entries, so we need to assure that it can operate reliably and it won’t break down,” Miller said “We have to make certain that the quality is of impeccable standards and that the system can demonstrate operational longevity in these areas.”

The design of the autonomous vehicle marks the first phase of what will potentially turn into a multi-phase project. WRPS has also expressed interest in having the robot detect obstacles in a changing environment, change filters at the site and monitor radiation. Miller said those challenges will most-likely be addressed in future phases of the project.

“This is a great opportunity, both for WSU, as well as for our students,” Miller said. “It creates opportunities for undergraduate research, as well as providing funding for graduate research. It is the perfect opportunity for us.”

The team plans to have the first phase of the autonomous vehicle completed and demonstrated to WRPS in the next few months. The team will conduct demonstrations and additional phases of development over the course of the year. When fully developed, the autonomous vehicle would be deployed in tank farms to support construction and operations.

Ultra high-performance concrete to encapsulate nuclear waste

Srinivas Allena, ���سԹ� associate professor of civil and environmental engineering, received a contract to develop an ultra-high performance cementitious

material to potentially be used as a grout to encapsulate solid secondary waste from the Hanford tank farms.

“WRPS is currently using a grout that they obtain from a local concrete supplier, which uses a regular cement mix with sand and some other chemical additives,” Allena said. “But the goal with our research is to use locally available materials to create a composite with low permeability, superior durability and greater stability that would perform at the same level as the commercially available pre-packaged ultra high-performance concrete.”

Allena said there is currently limited types of ultra high-performance concrete available on the market with high operational costs associated with use of the material. He said by using locally available materials and by optimizing mixture constituents with those that are more environmentally friendly with his team’s composite, however, they would be able to keep the costs low, while maintaining the same quality in the concrete and reducing the impact to the environment.

“We will be able to compare our grout materials with properties that WRPS is currently using and show the improved properties,” he said. “The goal is to provide a cheaper, more environmentally friendly option that will compete with the best product on the market.”

The team plans to have initial mixtures ready with their mechanical and durability properties evaluated by September.

The projects are a part of solving some of the world’s . They pertain particularly to developing and by harnessing technology to improve quality of life. The projects are also in line with WSU’s