OAK RIDGE, Tenn. – Fresh on the heels of demolishing the Bulk Shielding Reactor and Low Intensity Test Reactor over the past year, EM crews at Oak Ridge are now working to remove a third reactor at Oak Ridge National Laboratory (ORNL).
The Oak Ridge Research Reactor was an isotope production and irradiation facility from 1958 through 1987. It was permanently shut down in July 1987 and defueled.
The Oak Ridge Office of Environmental Management (OREM) and contractor UCOR are preparing the reactor for demolition. This is another in a line of projects transforming ORNL’s central campus by clearing away old excess, contaminated facilities.
Using a large diamond wire saw, UCOR safely removed the top portion of the 32-foot-tall reactor vessel located in the reactor facility. Crews will remove a second portion of the reactor after eliminating the remaining reactor connections. The final portion of the reactor is embedded in cement, and workers will remove it during the facility’s demolition.
“Demolishing this structure presents unique challenges,” said Don Gagel, UCOR project manager. “The upper section is being removed in two sections based on its radiation dose. The very top section was lower dose, but the next section requiring removal is higher dose. Segmenting these two sections results in more efficient, cost-effective transportation, and safe disposal.”
This work comes nearly a decade after employees first began work in the building after discovering water seepage from the reactor pool. To address the issue, workers placed concrete shielding and containment panels over the pool, drained it and injected a fixative to keep contamination in place.
A bright green color added to the fixative helped crews confirm that the fixative covered the entire pool’s surface. However, when water was added in the pool to begin deactivation efforts, the dye leached into the water and greatly reduced visibility in the pool.
EM crews responded by developing an ultraviolet light and hydrogen peroxide treatment skid that eliminated the green dye and cleared the pool, providing visibility to conduct deactivation tasks.
“The project team continues to solve problems associated with removing the Oak Ridge Research Reactor, allowing continued safe progress with this challenging job,” UCOR Area Project Manager Larry Brede said. “The workforce’s diligent efforts are paying dividends as evidenced by this first reactor section removal.”
Other hazardous materials removed from the reactor pool are being cut into smaller pieces and placed into waste transfer baskets underwater. Once full, these waste transfer baskets will be lifted, dried and loaded into cask liners for disposal.
Crews are slated to remove the next portion of the reactor vessel in January. Its removal is the first step required prior to deactivation in the remainder of the facility to prepare it for near-term demolition.
-Contributor: Carol Hendrycks
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