Professor and Recent Graduate Pursue Research at Hanford
Qin Ma and Nathan Reeves Study Glass Decomposition
By: Camlynne Waring
Nathan Reeves doesn’t like to be idle. In June, he graduated from Walla Walla University with majors in history, engineering, and mathematics, and Sept. 2, he will start classes at Harvard Law School. Until then, Reeves will be employing his engineering skills working on a project at Pacific Northwest National Laboratory in Richland, Wash. with WWU engineering professor Qin Ma. According to Reeves, the opportunity to work with Ma and the laboratory, a contractor for Hanford Nuclear Reservation, was too good to pass up.
As part of the Visiting Faculty Program, Ma and Reeves are working with a team to research how glass dissolves in water. Though glass dissolving in water may not be a concern in daily life, it is very important when the glass is storing nuclear waste.
“Any used radioactive materials must be ‘jailed’ so they will not be able to move around, especially if ground water is present when they are buried,” said Ma. Currently, a special kind of glass called waste-form glass is used to store radioactive material. Researchers expect that radioactive material must be immovable for thousands, and maybe even millions, of years. Can glass confine the hazardous material for that long? Questions on the methods and speed of glass decomposition must be answered quantitatively, said Ma.
Ma and Reeves’ project is a small piece of the puzzle. Using a glass that dissolves quickly, they are determining if glass with sharps, or jagged edges, decomposes at a different rate than glass without sharps. “It’s possible because there is some stress in the glass, it may decompose faster,” said Reeves.
To examine this, the team hammered a sheet of glass into tiny pieces. “If it’s wrong at the particle level, it’s going to be wrong at the bulk level,” Reeves said.
In addition to experiments, the team is using modeling techniques. Reeves wrote a program to create a two-dimensional model, which utilizes the “shrinking core model,” he says. The model may be used to simulate how a piece of glass may be dissolved in water. Reeves compared the model technique to moving a lawn around the edges, shrinking the boundary of the uncut grass with each pass or round.
“There is an international community studying glass decomposition,” said Reeves. Ma and Reeves hope that their research will shed some light on questions in the field. On Aug. 17, the two will end their work, though the project will be far from over. Ma will use his research knowledge to enhance his teaching, and Reeves will enter a new chapter in his life, trading Hanford for Harvard.