Radiological Characterization of the Hot Cells in the 327 Building

The 327 Building, located in the 300 Area of the Hanford Site, is currently undergoing a stabilization and deactivation project for the purpose of placing it in a safe and stable configuration. The stabilization/deactivation project will remove, reduce, and/or stabilize the industrial, radiological, and chemical hazards within the 327 Building. This paper will describe the suite of instruments developed to perform radiological characterization of the hot cells. The 327 Building contains significant quantities of high-dose-rate nuclear material and waste requiring storage or disposal outside the 300 Area. The building's ten shielded hot cells and their ancillary equipment are the primary contributors to this inventory of radioactive material hold-up. One task to be completed during this project is the disposition of these hot cells. The current technical baseline for deactivation of these hot cells is to remove the radiological inventory, decontaminate, size reduce/dismantle, package, load-out, and ship for ultimate disposal. An alternative approach for disposal of these hot cells consists of monolithic disposal. This alternative would require the ability to coordinate in-situ characterization with laboratory analysis of the hot cells. Due to the difficulty in accessing the interior of the hot cells, high background radiation, and extensive levels of contamination, a single conventional characterization method is not sufficient. A graded approach, combining a number of integrated non-destructive in-situ, characterization techniques coupled with standard laboratory sampling and analyses will be used to characterize the cells and provide a waste designation for the hot cells. The suite of equipment and/or techniques used for the radiological characterization of the hot cells consists of the following instruments. 1. An ISOCS characterized BEGE detector. 2. A Canberra CARTOGAM gamma camera. 3. Copper foils to detect neutrons. 4. Conventional destructive sampling. 5. A neutron pod detector. The identified technologies form a complete suite of instruments that provides fast and accurate information on the quantity and location of TRU material in the hot cells. This technique is expected to save several million dollars over the current technical baseline for the disposal of the hot cells.