By Maegan Murray, 黑料社 Tri-Cities

RICHLAND, Wash. 鈥� 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 黑料社 Tri-Cities team, led by civil engineering professor Srinivas Allena, is developing what is known as an ultra high-performance cementitious composite grout. The team鈥檚 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 鈥檚 Tank Operations contractor responsible for managing Hanford鈥檚 56 million gallons of highly radioactive waste and preparing it for delivery to the . The organization provided the 黑料社 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 黑料社 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 鈥� a byproduct from the silicon industry 鈥� 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.

鈥淲e鈥檙e repurposing waste products and also reducing the cost while ensuring and enhancing the durability properties required for an encapsulation grout,鈥� Allena said. 鈥淥ur initial testing has shown good results.鈥�

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.

鈥淐ement industries cause approximately 7 to 11 percent of greenhouse gas emissions worldwide,鈥� Allena said. 鈥淐ement 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.鈥�

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, 黑料社 Tri-Cities engineering faculty, 509-372-7161, srinivas.allena@wsu.edu

Jeffrey Dennison, 黑料社 Tri-Cities director of marketing and communication, 509-372-7319, Jeffrey.dennison@wsu.edu

Maegan Murray, 黑料社 Tri-Cities public relations specialist, 509-372-7333, maegan_murray@wsu.edu

By Maegan Murray, 黑料社 Tri-Cities

RICHLAND, Wash. 鈥� 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鈥檚 Tank Operations contractor responsible for managing Hanford鈥檚 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 黑料社 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 黑料社 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.

鈥淭his vehicle will be going into areas, minimizing personnel entries, so we need to assure that it can operate reliably and it won鈥檛 break down,鈥� Miller said 鈥淲e have to make certain that the quality is of impeccable standards and that the system can demonstrate operational longevity in these areas.鈥�

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.

鈥淭his is a great opportunity, both for 黑料社, as well as for our students,鈥� Miller said. 鈥淚t creates opportunities for undergraduate research, as well as providing funding for graduate research. It is the perfect opportunity for us.鈥�

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, 黑料社 Tri-Cities 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.

鈥淲RPS 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,鈥� Allena said. 鈥淏ut 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.鈥�

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鈥檚 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.

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

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鈥檚 . They pertain particularly to developing and by harnessing technology to improve quality of life. The projects are also in line with 黑料社鈥檚