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Title: In-Situ Chemical Precipitation of Radioactive Liquid Waste - 12492

This paper presented in-situ chemical precipitation for radioactive liquid waste by using chemical agents. Results are reported on large-scale implementation on the removal of {sup 137}Cs, {sup 134}Cs and {sup 60}Co from liquid radioactive waste generating from Nuclear Research and Training Centre. Total amount of liquid radioactive waste was 35 m{sup 3} and main radionuclides were Cs-137, Cs- 134 and Co-60. Initial radioactivity concentration of the liquid waste was 2264, 17 and 9 Bq/liter for Cs-137, Cs-134 and Co-60 respectively. Potassium ferro cyanide was selected as chemical agent at high pH levels 8-10 according to laboratory tests. After the process, radioactive sludge precipitated at the bottom of the tank and decontaminated clean liquid was evaluated depending on discharge limits. By this precipitation method decontamination factors were determined as 60, 9 and 17 for Cs-137, Cs-134 and Co-60 respectively. At the bottom of the tank radioactive sludge amount was 0.98 m{sup 3}. It was transferred by sludge pumps to cementation unit for solidification. By in situ chemical processing 97% of volume reduction was achieved. Using the optimal concentration of 0.75 M potassium ferro cyanide about 98% of the {sup 137}Cs can be removed at pH 8. The Potassium ferro cyanide precipitationmore » method could be used successfully in large scale applications with nickel and ferrum agents for removal of Cs-137, Cs-134 and Co- 60. Although DF values of laboratory test were much higher than in-situ implementation, liquid radioactive waste was decontaminated successfully by using potassium ferro cyanide. Majority of liquid waste were discharged as clean liquid. %97.2 volumetric amount of liquid waste was cleaned and discharged at the original site. Reduced amount of sludge transportation in drums is more economical and safer method than liquid transportation. Although DF values could be different for each of applications related to main specifications of original liquid waste, this study shows that in-situ treatment of liquid waste by using potassium ferro cyanide is not only a cost effective method but also reduce radiological risks as well. (authors)« less
Authors:
 [1]
  1. Cekmece Nuclear Research and Training Centre, Istanbul (Turkey)
Publication Date:
OSTI Identifier:
22293712
Report Number(s):
INIS-US--14-WM-12492
TRN: US14V1368115236
Resource Type:
Conference
Resource Relation:
Conference: WM2012: Waste Management 2012 conference on improving the future in waste management, Phoenix, AZ (United States), 26 Feb - 1 Mar 2012; Other Information: Country of input: France; 14 refs.
Research Org:
WM Symposia, 1628 E. Southern Avenue, Suite 9-332, Tempe, AZ 85282 (United States)
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CESIUM 134; CESIUM 137; COBALT 60; CYANIDES; DECONTAMINATION; EFFICIENCY; HAZARDS; LIQUID WASTES; LIQUIDS; POTASSIUM; PRECIPITATION; RADIOACTIVE WASTES; RADIOACTIVITY; REMOVAL; SLUDGES