TBP 용매추출에 의한 잔존 우라늄 제거공정 평가

이일희; 김광욱; 임재관; 권선길; 유재형

Journal of the Korean Industrial and Engineering Chemistry, Vol.9, No.2, 232-237, April, 1998

Evaluation of A Removal Process for the Residual Uranium from the Simulated Radwaste Solution by Solvent Extraction with TBP

이일희, 김광욱, 임재관, 권선길, 유재형

초록

본 연구에서는 19계 성분 원소들이 함유된 모의 방사성 용액으로부터 미량 잔존하고 있는 U을 분리하기 위한 최적 조건 설정 및 연속공정으로의 구성을 최적화하기 위한 공정 평가를 수행하였다. 실험은 TBP에 의한 용매추출 공정을 선정하여 총 18단 2조의 연속식 용매추출 장치인 혼합정치조를 이용하였다. U, Np, 및 Tc의 추출율은 각각 99.2%, 32.1%, 및 99.9%이며, 기타 원소들은 1∼4% 전도가 추출되었다. U의 경우 다성분계 회분식에서 얻어진 Nd나 Fe와 같은 공존원소의 영향으로 인하여 U이 약 80% 정도만이 추출된다는 기존 보고를 능가하는 것으로, 이는 다단 연속추출 장치의 특성에 기인하는 것 같다. 그리고 Np의 추출율 감소는 질산용액에 존재하는 다양한 산화가 상태에 기인하며, Tc의 경우는 Tc과 공존하고 있는 Zr 또는 U과의 착물 형성에 의해 추출율이 증가된 것으로 사료된다. 한편 유기상으로 추출된 모든 원소들은 0.01M의 질산에 의해 99% 이상이 수용상으로 역추출되었다. 이상의 결과로부터 TBP에 의한 잔존 U 제거 공정은 별 문제가 없다. 다만 Np이 추잔상과 U 생성물로 각각 분배되어 있으므로 방사성 핵종의 확산방지 측면에서 이를 한 공정에서 총괄 처리할 수 있는 공정 개발이 요구된다.

This study was carried out to find the optimal operating conditions for separation of residual uranium from the simulated radwaste solution containing 19 elements, and to evaluate the validity of the process. The selected process was based on the solvent extraction with TBP(tributyl phosphate). As an extractor, two miniature mixer-settlers with a total of 18 stages were used. Extraction yield of U, Np and Tc was about 99.2%. 32.1%, and 99.9%, respectively. The other elements were coextracted in the range of 1∼4%. Extraction yield of U exceeded those of the previous work performed with batch system, which resulted in the low extractability of U(about 80%) according to the coexisting element such as Nd and Fe. It was due to the characteristics of multi-stage extractor. On the other hand, low extractability of Np was caused by various oxidation states in the nitric acid medium. In the case of Tc, its high extractability may be attributed to the complex formation with Zr and U, which is not well proved yet. All elements extracted with TBP were stripped into aqueous phase more than 99% by 0.01M HNO₃. From the results, this process has no problem with respect to in the same step was required, because Np was distribution in the raffinate and U product, respectively.

[References]

Cains PW, Marples JAC, Walmsley D, "A Review of Alternative Waste Forms and Processes for Future Solidification of HLLW Waste," AERE/R 1130 (1986)
Bush RP, Mills AL, "Some Implication of the Partitioning of Actinides from HLLW," RECOD '94, London, U.K. (1994)
Song C, Glatz JP, He X, Bokelund H, Koch L, "Actinide Partitioning by Means of the TRPO Process," RECOD '94, London, U.K. (1994)
Madic C, Blanc P, Berthon L, "Actinide Partitioning from HLLW using the DIAMEX Process," RECOD '94, London, U.K. (1994)
ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part I (1978)
ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part II (1980)
ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part III (1981)
Kim KW, Lee EH, Shin YJ, Yoo JH, Park HS, J. Korean Ind. Eng. Chem., 6(1), 102 (1995)
Kim KW, Lee EH, Shin YJ, Yoo JH, Park HS, J. Korean Ind. Eng. Chem., 6(3), 397 (1995)
Kim KW, Lee EH, Shen YJ, Yoo JH, Park HS, Sep. Sci. Technol., 30(17), 3351 (1995)
Schulz WW, "Science and Technology of Tributyl Phosphate," CRS Press, Florida (1990)
Benedit M, Pigford TH, "Nuclear Chemical Engineering," 2nd ed., McGraw-Hill Book Co. (1981)
Vlasov VS, "Computer Programs for Calculation of the Cascade of Mixer-Settler," Personnel Communication (1995)
Escure H, Gourisse D, Lucas J, J. Inorg. Nucl. Chem., 33, 1871 (1971)
Morita Y, Kubota M, "The Recovery of Np (Literature Survey)," JAERI-M 84-043 (1984)
Adloff JP, Lieser KH, Pruett DJ, Wolf AP, "Radiochemica Acta-International Journal for Chemical Aspects of Nuclear Science and Technology," R. Oldenbourg Verlag, Munchen, Germany, 63 (1993)
Kolarik Z, Dressler P, Solvent Extr. Ion Exch., 7, 625 (1989)
Pruett DJ, "The Solvent Extraction of Heptavalent Tc and Re by TBP," ORNL/TM-8668 (1984)
Jassim TN, Lijenzin JO, Lundqvist R, Persson G, Sol. Extr. Ion Exch., 2, 405 (1984)
Apostolidis C, Glatz JP, Molinet R, "Recovery of MA from Irradiated SUPERFACT Fuels," Global 1995, Versailles, France, 2, 1027 (1995)
Tommasi J, Delpech M, "Nuclear Science Technology," Part III, Eur-17485 (1996)

[Referenced By]

[1] Cains PW, Marples JAC, Walmsley D, "A Review of Alternative Waste Forms and Processes for Future Solidification of HLLW Waste," AERE/R 1130 (1986)

[2] Bush RP, Mills AL, "Some Implication of the Partitioning of Actinides from HLLW," RECOD '94, London, U.K. (1994)

[3] Song C, Glatz JP, He X, Bokelund H, Koch L, "Actinide Partitioning by Means of the TRPO Process," RECOD '94, London, U.K. (1994)

[4] Madic C, Blanc P, Berthon L, "Actinide Partitioning from HLLW using the DIAMEX Process," RECOD '94, London, U.K. (1994)

[5] ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part I (1978)

[6] ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part II (1980)

[7] ICRP, "Limits for Intake of Radionuclides by Workers," ICRP Publication, Part III (1981)

[8] Kim KW, Lee EH, Shin YJ, Yoo JH, Park HS, J. Korean Ind. Eng. Chem., 6(1), 102 (1995)

[9] Kim KW, Lee EH, Shin YJ, Yoo JH, Park HS, J. Korean Ind. Eng. Chem., 6(3), 397 (1995)

[10] Kim KW, Lee EH, Shen YJ, Yoo JH, Park HS, Sep. Sci. Technol., 30(17), 3351 (1995)

[11] Schulz WW, "Science and Technology of Tributyl Phosphate," CRS Press, Florida (1990)

[12] Benedit M, Pigford TH, "Nuclear Chemical Engineering," 2nd ed., McGraw-Hill Book Co. (1981)

[13] Vlasov VS, "Computer Programs for Calculation of the Cascade of Mixer-Settler," Personnel Communication (1995)

[14] Escure H, Gourisse D, Lucas J, J. Inorg. Nucl. Chem., 33, 1871 (1971)

[15] Morita Y, Kubota M, "The Recovery of Np (Literature Survey)," JAERI-M 84-043 (1984)

[16] Adloff JP, Lieser KH, Pruett DJ, Wolf AP, "Radiochemica Acta-International Journal for Chemical Aspects of Nuclear Science and Technology," R. Oldenbourg Verlag, Munchen, Germany, 63 (1993)

[17] Kolarik Z, Dressler P, Solvent Extr. Ion Exch., 7, 625 (1989)

[18] Pruett DJ, "The Solvent Extraction of Heptavalent Tc and Re by TBP," ORNL/TM-8668 (1984)

[19] Jassim TN, Lijenzin JO, Lundqvist R, Persson G, Sol. Extr. Ion Exch., 2, 405 (1984)

[20] Apostolidis C, Glatz JP, Molinet R, "Recovery of MA from Irradiated SUPERFACT Fuels," Global 1995, Versailles, France, 2, 1027 (1995)

[21] Tommasi J, Delpech M, "Nuclear Science Technology," Part III, Eur-17485 (1996)