Approximately 2.32 million cubic feet and 154 thousand curies of low-level radioactive waste were disposed of in 2022. When storing low-level radioactive waste long-term, the leach resistance of solid forms of radioactive waste is of major importance in determining the release rate of radioisotopes. ANSI/ANS-16.1-2019 (R2024): Measurement Of The Leachability Of Solidified Low-Level Radioactive Wastes By A Short-Term Test Procedure provides a simple method for the quantitative comparison of the leach resistance of different radionuclides from different low-level radioactive materials.
Is Low-Level Radioactive Waste Harmful?
Low-level waste is radioactively contaminated industrial or research waste that is not high-level waste, transuranic waste, or uranium or thorium mill tailings. The wastes generally do not pose severe risks from their radiation fields, and there are disposal facilities that specialize in the near-surface disposal of low-level waste. Like all radioactive material, radioactive wastes will naturally decay over time and once they do, the waste is no longer hazardous. The time it will take for the radioactive material to decay, however, will range from a few hours to hundreds of millions of years.
The proper management of safely containing low-level waste is critical because there is risk associated with radionuclides migrating into the environment and entering the food chain through air, food, or water. Consuming food contaminated with radionuclides in a nuclear or radiological emergency will increase the amount of radioactivity in the body and could increase the health risks associated with exposure to radiation. The level of risk will depend on which radionuclides have been ingested and the amount of radioactivity that has been incorporated.
What Is ANSI/ANS-16.1?
ANSI/ANS-16.1-2019 (R2024) provides a procedure to measure and index the release rates of non-volatile radionuclides from low-level radioactive waste forms in demineralized water over a test period. The procedure can be applied to any material from which test specimens can be prepared by casting or cutting into a shape for which the surface area and volume can be determined. This American National Standard provides a rapid and economical means for screening optional materials, formulations, and processing methods to develop and select waste forms for more extensive testing. It was designed principally for comparisons of solid monolithic low-level radioactive waste forms generated from non-self-heating radioactive fluid (e.g., liquids, slurries, free-flowing powders) waste streams.
The standard’s method is not intended to provide information suitable for assessing waste form performance or qualification for disposal. The test method described in ANSI/ANS-16.1-2019 (R2024) cannot be used for performance assessment of waste forms because it does not address the radionuclide release mechanisms or effects of environmental conditions on the test response. Instead, it provides an economical and rapid method for comparing the leachability of alternative waste forms.
How Is Low-Level Nuclear Waste Dealt With?
Low-level waste includes items that have become contaminated with radioactive material or have become radioactive through exposure to neutron radiation. A variety of industries, hospitals and medical institutions, educational and research institutions, private or government laboratories, and nuclear fuel cycle facilities generate low-level nuclear waste. This waste typically consists of contaminated protective shoe covers and clothing, cleaning rags, medical tubes, hypodermic syringes, wiping rags, mops, filters, reactor water treatment residues, equipment/tools, luminous dials, swabs, injection needles, syringes, laboratory animal carcasses, and tissues.
Current management of low-level waste has much improved containment. Historically, management of the wastes involved shallow burial in unconsolidated materials (e.g., sand), often in unlined trenches. Now, low-level waste is typically stored on-site by licensees, either until it has decayed away and can be disposed of as ordinary trash, or until amounts are large enough to warrant a shipment to a low-level waste disposal site in containers approved by the Department of Transportation.
ANSI/ANS-16.1-2019 (R2024): Measurement Of The Leachability Of Solidified Low-Level Radioactive Wastes By A Short-Term Test Procedure is available on the ANSI Webstore.