Interested in a career in engineering? Check out the ABET-accredited and nationally recognized 厙ぴ勛圖 engineering programs at��tricities.wsu.edu/engineering.

By Maegan Murray, 厙ぴ勛圖

RICHLAND, Wash. ��� A team of Washington State University Tri-Cities student mechanical engineers partnered with Washington River Protection Solutions (WRPS) to design a prototype of an instrument that could one day be implemented to assess the exact location, amount and arrangement of solid radioactive waste in Hanford tanks.

The device could solve a significant challenge out at the site, providing engineers and scientists at Hanford with a three-dimensional and much more reliable picture of the layout of solid waste. The device would allow them to better assess and prepare for situations at the site in the future, as compared with their current methods.

Currently, WRPS use devices that measure only one location in the tanks. They use either a sludge weight or other device that must sink down to the bottom of the liquid level of the waste in the tanks to determine the level of the solid waste. The current devices, however, do not provide information about the solids level at other locations in the tanks, the students said.

For their senior design capstone project, the student group, comprised of Bryan Chronister, Tanner Reyff, Rayce Barnes and Tomokazu Hager, designed a deploying system known as SLIM, or Solid Liquid Interface Monitor, that resists radioactive contamination and decay, and can be telescoped to different depths of the tank that uses a sonar device to get an accurate picture of the tank. The device could be left in the tanks and serve as a long-term solution in creating a reliable picture of the placement of the waste in the tanks, Reyff said.

���Currently, we have a 35-foot design from grade level, which is ground level, where it is submerged into the liquid level of the waste, and takes about five minutes to do a full scan of the tank with the sonar device,��� Hager said. ���Essentially, it creates a topographical scan of the full tank, which can be used for a range of future uses out at the Hanford Site.���

Developing the design

The student group spent their first semester developing four different designs, which they consolidated into one seamless design.

The team���s final design uses a winch to lower a telescoping tube into the supernatant, or liquid waste, that contains an existing sonar device that has been proven to withstand radioactive exposure. The tubing is encapsulated in a chamber that protects the outside environment from radioactive contamination. When the device is removed, it has a high-impact spray system that washes the tubing as it is being removed and also further reduces potential for contamination.

���We created a rigid design that provides control to the depth that is required and a stable insertion that would produce an accurate image of the solid waste within the tanks,��� Reyff said. ���The goal was to minimize the amount of radiation exposure that is also remotely operated.���

Supporting students to invest in the future

WRPS��� primary goal is to reduce the environmental risk posed by 56 million gallons of radioactive and chemical waste stored in 177 underground tanks at the Hanford Site that dates back to as early as World War II. The organization partners with WSU to develop technology to support that mission, as most technology must be specifically tailored to their needs due to the unique origins of the site as the home of the first large-scale nuclear reactor in the world.

Kayle Boomer, manager of the Technology Management and Field Solution group with WRPS��� Chief Technology Office, said he is impressed with the student���s design and that is has potential for out at Hanford.

���The team worked well together,��� Boomer said. ���They were very diligent and tried to ensure that the design addressed as many design requirements as possible. The other Hanford engineers working with them thought they were developing a workable design for the tank farm.���

WRPS provided the student group, as well as one additional student engineering group, with a total of $10,000 to develop prototypes that could one day be applied out at the Hanford Site. The other student group, which is comprised of students Anthony Jenkins, Melissa Rivas, Oleg, Tyshchuk and Michelle Wheeler, developed a device to sample any interface within the Hanford tanks.

���It was a great experience working with the WSU senior engineering students on their senior design project,��� said Jon Barnes, design services engineer for WRPS.�� ���Their energy and creativity was infectious. I���m hoping I���ll see them again in the engineering work world, and perhaps get a change to work together as peers.���

Jason Vitali, chief technology officer for WRPS, said the solutions identified by the students during their capstone project are extremely creative, thorough, and have the potential for resolving some of the challenges they encounter in the high-hazard environment.

���It is important that the students continue to tackle real-world challenges during their education so they are able to transition after school and make contributions early in their professional careers,��� he said.

 

Interested in a career in engineering? Check out the ABET-accredited and nationally recognized 厙ぴ勛圖 engineering programs at��tricities.wsu.edu/engineering.

By Maegan Murray, 厙ぴ勛圖

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 厙ぴ勛圖 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, 厙ぴ勛圖 engineering faculty, 509-372-7161, srinivas.allena@wsu.edu

Jeffrey Dennison, 厙ぴ勛圖 director of marketing and communication, 509-372-7319, Jeffrey.dennison@wsu.edu

Maegan Murray, 厙ぴ勛圖 public relations specialist, 509-372-7333, maegan_murray@wsu.edu