Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. This paper describes the GSAK approach, while Part II presents the test results.
Gamma-ray spectrometry combined with acceptable knowledge (GSAK) is a technique for the characterization of certain remote-handled transuranic (RH-TRU) wastes. GSAK uses gamma-ray spectrometry to quantify a portion of the fission product inventory of RH-TRU wastes. These fission product results are then coupled with calculated inventories derived from acceptable process knowledge to characterize the radionuclide content of the assayed wastes. GSAK has been evaluated and tested through several test exercises. This paper describes these tests and their results; while the former paper in this issue presents the methodology, equipment and techniques.
Authors:W. Sandoval, M. Cournoyer, L. Bustos, D. Quintana, and L. Ortega
As part of the technical support CST-12 provides for a wide variety of defense and nondefense programs within Los Alamos National
Laboratory (LANL) and the Department of Energy (DOE) complex, new waste minimization technique is under development for radiological
volatile organic analysis (Hot VOA). Currently all Hot VOA must be run in a glovebox. Several types of samples contain TRU
radiological waste in the form of particulates. By prefiltering the samples, through a 1.2 micron syringe and counting the
radioactivity, it has been found that many of the samples can be analyzed outside of a glovebox. In the present investigation,
the types of Hot VOA samples that can take advantage of this new technique, the volume and types of waste reduced, and the
experimental parameters will be discussed. Overall, the radioactive waste generated is minimized.
The Savannah River Site (SRS) Burial Ground had a container labeled as Box 33 for which they had no reliable solid waste stream designation. The container consisted of an outer box of dimensions 48″ × 46″×66″
and an inner box that contained high density and high radiation dose material. From the outer box Radiation Control measured
an extremity dose rate of 22 mrem/h. With the lid removed from the outer box, the maximum dose rate measured from the inner
box was 100 mrem/h extremity and 80 mrem/h whole body. From the outer box the material was sufficiently high in density that
the Solid Waste Management operators were unable to obtain a Co-60 radiograph of the contents. Solid Waste Management requested
that the Analytical Development Section of Savannah River National Laboratory perform a γ-ray assay of the item to evaluate
the radioactive content and possibly to designate a solid waste stream. This paper contains the results of three models used
to analyze the measured γ-ray data acquired in an unusual configuration.
Authors:A. Plionis, S. Garcia, E. Gonzales, D. Porterfield, and D. Peterson
Lead is a hazardous substance, making it a disposal and industrial hygiene problem. The potential for creating mixed waste
or mixed TRU waste exists if the lead becomes contaminated. The disposal of either waste stream is extremely difficult and
costly. Bismuth is a non-hazardous material with shielding characteristics similar to lead. An HPGe was characterized using
detector shielding composed of lead and polyethylene-based-bismuth to compare the shielding efficacy of both materials. Polymer-bismuth
bricks may be recommended as gamma spectrometer shielding for sensitive low-energy measurements.
The characterization of radioactive hazardous waste, also known as transuranic "mixed waste" has to be completed before it can be classified for proper treatment (incinerator, mechanical compaction or thermal treatment), packing, and transport. The characterization of the TRU mixed waste is not only complex process but rather an expensive undertaking. The process knowledge is the basic foundation of characterization. It is the documented knowledge of processes and materials that generated the waste. The transuranic waste Quality Assurance Program Plan (QAPP) defines the Data Quality Objectives (DQO's) and provides the scope of analytical parameters and methods required to accurately characterize the radioactive mixed waste. Based on the historical data and process knowledge a sampling and analysis plan can be developed to characterize the radioactive hazardous waste. Based on the characterization, an assessment of the regulatory status can be made before the waste could be accepted for disposal at the WIPP facility. The Waste Acceptance Criteria (WAC) developed by WIPP defines the parameters for receiving and final disposal of the TRU waste. The sets of criteria, such as: heat generated, fissile gram equivalent (FGE), plutonium-equivalent (PE) curies, and specifications of a dose rate have to be met before the waste is accepted for deep geological disposal. The characterization of radioactive waste becomes even more complex due to the presence of iron base metals/alloys, aluminum base metals/alloys, organic, chelating agents that are mixed with plastic, rubber, cellulose, soils and cement. Some of the modern characterization technologies that are under development and currently used for TRU mixed wastes are: nondestructive examination, nondestructive assay, headspace gas analysis, and drum coring for Resources Conservation Recovery Act (RCRA) sampling.