Leaching Behavior and Mechanism of Ceramic Waste Forms

doi:10.15541/jim20180374

Abstract

Abstract:

The radionuclides in high-level radioactive waste (HLW) forms may be leached out over geological time and enter the human environment with groundwater circulation after deep geological disposal. This is likely the potential way for radionuclides to enter the biosphere. Therefore, the long-term chemical durability of HLW waste forms is the key issue for selecting suitable waste forms. Ceramic waste forms, regarded as the second generation of HLW forms, are of long-range ordered structures, whose physical properties can be easily characterized quantitatively. It is of great importance and significance to study the leaching mechanism of ceramic waste forms. However, not only the studies of leach mechanisms, but also the evaluation methods of ceramic waste forms are in their infancy. There is also lack of the standards of ceramic waste forms received by the repository. The present paper summarizes the research methods and key points of chemical durability, reviews the research status of hydrothermal alteration of related ceramics, and analyzes the leaching rate of radionuclides. In addition, the paper also discusses the influencing factors and their influencing modes, and finally concludes the leaching mechanisms and existing problems.

Key words: chemical durability, waste form, leaching mechanism, review

CLC Number:

TL94

Ya-Ping SUN, Hong-Long WANG, Jian CHU, Xu WANG, She-Qi PAN, Ming ZHANG. Leaching Behavior and Mechanism of Ceramic Waste Forms[J]. Journal of Inorganic Materials, 2019, 34(5): 461-468.

Figures/Tables 8

References 48

[1]	WANG J, SU R, CHEN W M , et al. Deep geological disposal of high-level radioactive wastes in China. Chinese Journal of Rock Mechanics & Engineering, 2006,25(4):649-658. DOI URL
[2]	EWING R C . Long-term storage of spent nuclear fuel. Nature Materials, 2015,14(3):252-257. DOI URL PMID
[3]	谭宏斌, 李玉香 . 放射性废物固化方法综述. 云南环境科学, 2004,23(4):1-3. DOI URL
[4]	CHEN F Y, JIE W Q, DELBERT E D . Corrosion property of iron phosphate simulated HLW melts. Journal of Inorganic Materials, 2000,15(4):653-659. DOI URL
[5]	EWING R C . Nuclear waste forms for actinides. Proc. Nat. Acad. Sci., 1999,96(7):3432-3439. DOI URL PMID
[6]	WANG L L, XIE H, CHEN Q Y , et al. Synthesis and charaterization of thorium-doped Nd₂Zr₂O₇ pyrochlore. Journal of Inorganic Materials, 2015,30(1):81-86.
[7]	DONALD I W, METCALFE B L, TAYLOR R N J . The immobilization of high level radioactive wastes using ceramics and glasses. Journal of Materials Science, 1997,32(22):5851-5887. DOI URL
[8]	何涌 . 高放废液玻璃固化体和矿物固化体性质的比较. 辐射防护, 2001,21(1):43-47. DOI URL
[9]	HAYWARD P J, CECCHETTO E V . Development of sphene-based glass ceramics tailored for canadian waste disposal conditions. Mater. Res. Soc. Symp. Proc., 1981,6:91-97. DOI URL
[10]	盛嘉伟, 罗上庚, 汤宝龙 . 高放废液的玻璃固化及固化体的浸出行为与发展情况. 硅酸盐学报, 1997,25(1):83-88.
[11]	张华 . 高放固化体处置条件下的浸出和模型研究. 北京: 中国原子能科学研究院博士学位论文, 2004.
[12]	MENDEL J E . Nuclear Waste Materials Characterization Center. Topp S V, Semiannual progress report, PNL-5683 America, 1985: 1-54.
[13]	C1285-02, Standard test methods for determining chemical durability of nuclear, hazardous, and mixed waste glasses and multiphase glass ceramics: The product consistency test (PCT).
[14]	吴萍萍, 张骋, 徐海芳 , 等. 玻璃固化体抗浸蚀性能实验研究进展. 现代技术陶瓷, 2010,31(3):28-34. DOI URL
[15]	EJ/1186-2005, 放射性废物体和废物包的特性鉴定.
[16]	KÖHLER S J, HAROUIYA N, CHAÏRAT C , et al. Experimental studies of REE fractionation during water-mineral interactions: REE release rates during apatite dissolution from pH 2.8 to 9.2. Chem. Geol., 2005,222(3/4):168-182. DOI URL
[17]	ICENHOWER J P, STRACHAN D M, LINDBERG M J , et al. Dissolution kinetics of titanate-based ceramic waste forms: results from single-pass flow tests on radiation damaged specimens. United States: N.p., DOI: 10.2172/15003935.
[18]	HAYWARD P J, WATSON D G, MCILWAIN A K , et al. Leaching studies of sphene ceramics containing substituted radionuclides. Nuclear and Chemical Waste Management, 1986,6(1):71-80. DOI URL
[19]	GEISLER T, PIDGEON R T, KURTZ R , et al. Experimental hydrothermal alteration of partially metamict zircon. Am. Mineral., 2003,88(10):1496-1513.
[20]	TOULHOAT N, TOULHOAT N, MONCOFFRE N , et al. Enhancement of zirconolite dissolution due to water radiolysis . MRS Proceedings, 2006, 985: 0985-NN09-04. DOI URL
[21]	BERGER A, GNOS E, JANOTS E , et al. Formation and composition of rhabdophane, bastnäsite and hydrated thorium minerals during alteration: implications for geochronology and low-temperature processes. Chem. Geol., 2008,254(3):238-248. DOI URL
[22]	张华, 杨建文, 李宝军 , 等. 富烧绿石在模拟处置条件下的浸出行为研究. 核化学与放射化学, 2004,26(2):65-70. DOI URL
[23]	FRUGIER P, MARTIN C, RIBET I , et al. The effect of composition on the leaching of three nuclear waste glasses: R7T7, AVM and VRZ.[J]. Nucl. Mater., 2005,346(2/3):194-207. DOI URL
[24]	PIRLET V. Influence of the near-field conditions on the mobile concentrations of Np and Tc leached from vitrified HLW. MRS Proceedings, 2004, 824: CC7. 5.
[25]	李鹏, 丁新更, 杨辉 , 等. 钙钛锆石玻璃陶瓷体的晶化和抗浸出性能. 硅酸盐学报, 2012,40(2):324-328.
[26]	盛嘉伟, 罗上庚, 汤宝龙 , 等. 90-19/U模拟高放玻璃固化体的浸出特性评价. 核化学与放射化学, 1995,17(1):1-6. DOI URL
[27]	SHIN H Y, PARK H, YOO K . The effect of temperature on the leaching of monazite obtained from heavy mineral sands. Geosystem Engineering, 2012,15(2):118-122. DOI URL
[28]	HAWTHORNE F C, GROAT L A, RAUDSEPP M , et al. Alpha- decay damage in titanite. Am. Mineral., 1991,76(3/4):370-396.
[29]	滕元成, 曾冲盛, 任雪潭 , 等. 合成榍石的化学稳定性. 原子能科学技术, 2010,44(1):14-19.
[30]	GEISLER T, ZHANG M SALJE E K H, ., Recrystallization of almost fully amorphous zircon under hydrothermal conditions: an infrared spectroscopic study.[J]. Nucl. Mater., 2003,320(3):280-291. DOI URL
[31]	RIZVANOVA N G, GAIDAMAKO I M, LEVCHENKOV O A , et al. Interaction of metamict zircon with fluids of various composition. Geochemistry International, 2007,45(5):465-477. DOI URL
[32]	TRIBET M, TOULHOAT N, MONCOFFRE N , et al. Leaching of a zirconolite ceramic waste-form under proton and He ²+ irradiation . Radiochimica Acta, 2008,96(9/10/11):619-624.
[33]	PÖML P, GEISLER T, COBOS-SABATÉ J , et al. The mechanism of the hydrothermal alteration of cerium- and plutonium-doped zirconolite.[J]. Nucl. Mater., 2011,410(1):10-23.
[34]	PÖML P, MENNEKEN M, STEPHAN T , et al. Mechanism of hydrothermal alteration of natural self-irradiated and synthetic crystalline titanate-based pyrochlore. Geochim . Cosmochim Acta., 2007,71(13):3311-3322. DOI URL
[35]	MITAMURA H, MATSUMOTO S, STEWART M W A , et al. α-Decay damage effects in curium-doped titanate ceramic containing sodium-free high-level nuclear waste.[J]. Am. Ceram. Soc., 1994,77(9):2255-2264. DOI URL
[36]	EWING R C, HAAKER R F, LUTZE W . Leachability of zircon as a function of alpha dose. MRS Online Proceeding Library, 1980,11(1):389-397. DOI URL
[37]	BEGG B D, HESS N J, WEBER W J , et al. Heavy-ion irradiation effects on structures and acid dissolution of pyrochlores.[J]. Nucl. Mater., 2001,288(2):208-216. DOI URL
[38]	GEISLER T, TRACHENKO K, RÍOS S , et al. Impact of self-irradiation damage on the aqueous durability of zircon (ZrSiO₄): implications for its suitability as a nuclear waste form. Journal of Physics Condensed Matter, 2003,15(37):1597-1605. DOI URL
[39]	SALJE E K H, CHROSCH J, EWING R C . Is “metamictization” of zircon a phase transition? Am. Mineral., 1999,84(7/8):1107-1116.
[40]	TRACHENKO K, DOVE M T, SALJE E K H . Reply to comment on 'large swelling and percolation in irradiated zircon'. Journal of Physics Condensed Matter, 2003,15(15):6457-6471. DOI URL
[41]	TROCELLIER P, DELMAS R . Chemical durability of zircon. Nuclear Inst and Methods in Physics Research B, 2001,181(1):408-412.
[42]	GEISLER T, PIDGEON R T, BRONSWIJK W V , et al. Transport of uranium, thorium, and lead in metamict zircon under low- temperature hydrothermal conditions. Chem. Geol., 2002,191(1):141-154. DOI URL
[43]	GEISLER T, RASHWAN T, RAHN A A , et al. Low-temperature hydrothermal alteration of natural metamict zircons from the eastern desert, Egypt. Mineralogical Magazine, 2003,67(3):485-508. DOI URL
[44]	GEISLER T, SCHALTEGGER U, TOMASCHEK F . Re-equilibration of zircon in aqueous fluids and melts. Elements, 2007,3(1):43-50.
[45]	ZHANG M, MADDRELL E R, ABRAITIS P K , et al. Impact of leach on lead vanado-iodoapatite [Pb₅(VO₄)₃I]: an infrared and Raman spectroscopic study. Materials Science & Engineering B, 2007,137(1):149-155. DOI URL
[46]	GEISLER T, PÖML P, STEPHAN T , et al. Experimental observation of an interface-controlled pseudomorphic replacement reaction in a natural crystalline pyrochlore. Am. Mineral., 2005,90(10):1683-1687. DOI URL
[47]	GEISLER T, ULONSKA M, SCHLEICHER H , et al. Leaching and differential recrystallization of metamict zircon under experimental hydrothermal conditions. Contrib. Mineral. Petrol., 2001,141(1):53-65.
[48]	LIAN J, ZU X T, KUTTY K V G , et al. Ion-irradiation-induced amorphization of La₂Zr₂O₇ pyrochlore. Phys. Rev. B, 2002, 66(66): 054108-1-5.

Parameters	Glass	Ceramic
Loading of waste/wt%	10-30	15-30
Density/(g·cm^-3)	2.5-2.8	3.0-5.8
Leach rate/(g·cm^-2·d^-1)	10^-4-10^-7	10^-6-10^-10
Anti-pressure ability	Low	High
Radiation tolerance/Gy	10^-9	~10^-9

Parameters	Glass	Ceramic
Loading of waste/wt%	10-30	15-30
Density/(g·cm^-3)	2.5-2.8	3.0-5.8
Leach rate/(g·cm^-2·d^-1)	10^-4-10^-7	10^-6-10^-10
Anti-pressure ability	Low	High
Radiation tolerance/Gy	10^-9	~10^-9

Mineral	Formula	Immobilized nuclide^a
Zircon	ZrSiO₄	An
Titanite	CaTiSiO₅	Ln, An
Apatite	Ca₅(PO₄)₃(OH, F, O)	U, Th, REE, I, Cs
Monazite	CePO₄	Ce, La, Eu, Gd, U, LREE
Xenotime	YPO₄	HREE
Pyrochlore	CaUTi₂O₇	Ln, An
Baddeleyite	ZrO₂	Ln, An
Perovskite	CaTiO₃	Sr, REE, Fe, Na, An
Zirconolite	CaZrTi₂O₇	Ln, An, Fe, Ni, Cr, Zr
Brannerite	UTi₂O₆	Ln, An
Rutile	TiO₂	Zr
Alkali Psilomelane	BaA1₂Ti₆O₁₆	Cs, Sr, Ba, Rb, A1

Mineral	Formula	Immobilized nuclide^a
Zircon	ZrSiO₄	An
Titanite	CaTiSiO₅	Ln, An
Apatite	Ca₅(PO₄)₃(OH, F, O)	U, Th, REE, I, Cs
Monazite	CePO₄	Ce, La, Eu, Gd, U, LREE
Xenotime	YPO₄	HREE
Pyrochlore	CaUTi₂O₇	Ln, An
Baddeleyite	ZrO₂	Ln, An
Perovskite	CaTiO₃	Sr, REE, Fe, Na, An
Zirconolite	CaZrTi₂O₇	Ln, An, Fe, Ni, Cr, Zr
Brannerite	UTi₂O₆	Ln, An
Rutile	TiO₂	Zr
Alkali Psilomelane	BaA1₂Ti₆O₁₆	Cs, Sr, Ba, Rb, A1

Sample	State	Temperature/ ℃	(SA/V)/ (m^-1·g^-1)	Duration time/d
MCC-1	Static	40, 70, 90	10	3, 7, 14, 28
MCC-2	Static	150, 200, 250	10	3, 7, 14, 28
MCC-3	Static	90, 150	680
MCC-4	Dynamic	75
PCT-A	Static	90	1000	7
PCT-B	Static	90	1000^b	28
PCT-C	Static	40, 70, 90	1000^b	28
PCT-D	Static	90	1000^b	56, 182, 364…
PCT-E	Static	40, 70, 90	1000^b	56, 182, 364…