Treatability study on the use of by-product sulfur in Kazakhstan for the stabilization of hazardous and radioactive wastes

The Republic of Kazakhstan generates significant quantities of excess sulfur from the production and refining of petroleum reserves. In addition, the country also produces hazardous, and radioactive wastes which require treatment/stabilization. In an effort to find secondary uses for the elemental sulfur, and simultaneously produce a material which could be used to encapsulate, and reduce the dispersion of harmful contaminants into the environment, BNL evaluated the use of the sulfur polymer cement (SPC) produced from by-product sulfur in Kazakhstan. This thermoplastic binder material forms a durable waste form with low leaching properties and is compatible with a wide range of waste types. Several hundred kilograms of Kazakhstan sulfur were shipped to the U.S. and converted to SPC (by reaction with 5 wt% organic modifiers) for use in this study. A phosphogypsum sand waste generated in Kazakhstan during the purification of phosphate fertilizer was selected for treatment. Waste loading of 40 wt% were easily achieved. Waste form performance testing included compressive strength, water immersion, and Accelerated Leach Testing. 14 refs., 7 figs., 6 tabs

Sorption (K d ) Measurements in Support of Dose Assessments for Zion Nuclear Station Decommissioning -14228

ABSTRACT The Zion Nuclear Power Station is being decommissioned. ZionSolutions proposes to leave much of the below grade structures in place and to fill them with "clean" concrete demolition debris from the above grade parts of the facility. The Brookhaven National Laboratory (BNL) conducted a study commissioned by ZionSolutions to provide site-specific data for performance assessment calculations to support the request to terminate the NRC license and allow unrestricted use of the facility. Specifically, the distribution coefficient (K d ) for five radionuclides of concern using site-specific soils and groundwater was measured by following ASTM C1733-10, Standard Test Methods for Distribution Coefficients of Inorganic Species by the Batch Method. The radionuclides of concern are Fe-55, Co-60, Ni-63, Sr-90, and Cs-137. In the testing, Sr-85 was used as an analogue for Sr-90 because it behaves similarly with respect to sorption and has a gamma emission that is easier to detect than the beta emission from Sr-90. Site-specific soils included disturbed sand (sand removed during construction and used as backfill), native sand, silt/clay and silt. In addition, two concrete cores from the Unit-1 Containment Building and the Crib House were broken into particles less than 2 mm in size and tested to obtain distribution coefficients for the five nuclides. For Fe-55 and Co-60, the soils and the concretes removed almost all of these radionuclides in solution. For Ni-63, K d values in the soils ranged from 62 to 331 with the disturbed sand having the highest sorption for Ni. The results indicate values of K d much greater than 1000 for Ni-63 exposed to concrete. Strontium-85 exhibited very little sorption in all media with K d values ranging from 2 to 6 in the soils and 10 to 20 in the concretes. Cesium-137 exhibited substantial sorption in the soils with K d values ranging from 500 to 3000 in the soils. The high K d value for Cs occurred in the silty/clay soil. Clay is known to have a high affinity for Cs. The sorption for Cs was far lower in the concrete with K d values ranging from 45 to 85

Efforts to Reduce Radioactive Wastes at High Flux Advanced Neutron Application Reactor (HANARO) in Korea -9190

ABSTRACT The High-flux Advanced Neutron Application Reactor (HANARO) has the equipment to treat the gaseous radioactive waste generated within itself but it does not have proper ways to treat the waste in either a liquid or solid form. For the last 5 years, every effort has been made to reduce the radioactive wastes in HANARO. Improvements of the equipment and operating procedures regarding the generation of radioactive waste in the field have resulted in an effective reduction of the radioactive waste. In addition, as an outgrowth of the research efforts in connection with the demand in the field, several new methods have been developed to effectively treat the radioactive waste. Efforts to reduce and treat the radioactive waste in HANARO will continue and that will contribute greatly to an improvement of the reliability and safety of HANARO