Radionuclides from Nature to Nature: Recent Progress in Immobilization of High Level Nuclear Wastes in SYNROC

doi:10.15541/jim20200247

Abstract

Abstract:

The production of nuclear energy, the development of nuclear energy, and the development of nuclear weapons inevitably produce radioactive waste among which the existing high-level radioactive waste is one of the most difficult to deal with. With the implementation of “actively developing nuclear power” strategy in China, the safe and effective disposal of radioactive waste has become a key issue in addressing the sustainable development of nuclear power. SYNROC solidification is considered as the ideal medium material for the second generation of solidified high-level radioactive waste. Based on the review of the concept of synroc solidification and the classification of candidate mineral host, we mainly introduce the latest research progress in the rapid synthesis method of SYNROC, the nucleation mechanism, and the long-term stability evaluation, in the path that though the road is hindered and long, the line is approaching if striving forward. Finally, the existing weakness of SYNROC curing is pointed out, and the research direction and development trend that should be paid attention to in the future are proposed.

Key words: high-level radioactive waste, synthetic rock, immobilization, nuclide, long-term stability

CLC Number:

TQ174

DUAN Tao, DING Yi, LUO Shilin, ZHANG Shengtai, LIU Jian. Radionuclides from Nature to Nature: Recent Progress in Immobilization of High Level Nuclear Wastes in SYNROC[J]. Journal of Inorganic Materials, 2021, 36(1): 25-35.

Figures/Tables 8

References 74

[1]	HATCH L P . Ultimate disposal of radioactive wastes. Am. Sci., 1953,41(3):410-421.
[2]	RINGWOOD A, KESSON S, WARE N ,et al. Immobilisation of high level nuclear reactor wastes in SYNROC. Nature, 1979,278(5701):219-223.
[3]	SICKAFUS K E, MINERVINI L, GRIMES R W ,et al. Radiation tolerance of complex oxides. Science, 2000,289(5480):748-751.
[4]	RAK Z, EWING R C, BECKER U . Ferric garnet matrices for immobilization of actinides. J. Nucl. Mater., 2013,436(1/2/3):1-7.
[5]	CLARKE D R . Ceramic materials for the immobilization of nuclear waste. Annu. Rev. Mater. Sci., 1983,13(1):191-218.
[6]	ROBERT L E J . Radioactive Waste Management. Annu. Rev. Part Sci., 1990,40:79-112.
[7]	MONTEL J M . Minerals and design of new waste forms for conditioning nuclear waste. Cr. Geosci., 2011,343(2-3):230-236.
[8]	ZUR LOYE H C, BESMANN T, AMOROSO J ,et al. Hierarchical materials as tailored nuclear waste forms: a perspective. Chem Mater., 2018,30(14):4475-4488.
[9]	MORRISON G, SMITH M D, ZUR LOYE H C. Understanding the formation of salt-inclusion phases: an enhanced flux growth method for the targeted synthesis of salt-inclusion cesium halide uranyl silicates. J. Am. Chem. Soc., 2016,138(22):7121-7129
[10]	BURNS P C, EWING R C, NAVROTSKY A . Nuclear fuel in a reactor accident. Science, 2012,335:1184-1188
[11]	卢喜瑞, 董发勤, 段涛 . 钆锆烧绿石固化錒系核素机理及稳定性. 北京: 科学出版社, 2016.
[12]	顾忠茂 . 核废物处理技术. 北京: 原子能科学出版社, 2009.
[13]	ORLOVA A I, OJOVAN M I . Ceramic mineral waste-forms for nuclear waste immobilization. Materials, 2019,12:2638.
[14]	PROUST V, JEANNIN R, WHITE F D ,et al. Tailored perovskite waste forms for plutonium trapping. Inorg Chem., 2019,58(5):3026-3032.
[15]	FINKELDEI S, STENNETT M C, KOWALSKI P M ,et al. Insights into the fabrication and structure of plutonium pyrochlores. J Mater. Chem. A, 2020,8:2387-2403
[16]	ADEL, MESBAH, NICOLAS,et al. Incorporation of thorium in the zircon structure type through the Th₁-_xEr_x(SiO₄)₁-_x, 2016,55:11273-11282.
[17]	LI Y H, WANG Y Q, ZHOU M ,et al. Light ion irradiation effects on stuffed Lu₂(Ti₂. _xLu_x)O₇-_x_/2 (x=0, 0.4 and 0.67) structures Nucl. Instrum. Meth. B, 2011,269(18):2001-2005.
[18]	YANG D Y, XU C P, FU E G , , et al. Structure. Structure and radiation effect of Er-stuffed pyrochlore Er₂(Ti₂-_xEr_x)O₇-_x_/2(x=0-0.667). Nucl. Instrum. Meth. B, 2015, 356-357:69-74.
[19]	李玉红, 许春萍 . Ne离子束辐照引起Gd₂Ti₂O₇烧绿石体积肿胀效应研究. 原子核物理评论, 2011(3):68-72.
[20]	XU M, WU Y, WEI Y . Stable solidification of silica-based ammonium molybdophosphate absorbing cesium using allophane: mechenical property and leaching studies. J. Radioanal. Nucl. Ch., 2018,316:1313-1321.
[21]	WU Y, XU M, WEI Y ,et al. Stable solidification of silica-based ammonium molybdophosphate in ceramic matrices and its cesium- leaching properties. Chem Lett., 2018,47(2):179-182.
[22]	DING Y, LI Y J, JIANG Z D ,et al. Phase evolution and chemical stability of the Nd₂O₃-ZrO₂-SiO₂ system synthesized by a novel hydrothermal-assisted Sol-Gel process. J Nucl. Mater., 2018,510:10-18.
[23]	LI S, YANG X, LIU J ,et al. First-principles calculations and experiments for Ce ⁴+ effects on structure and chemical stabilities of Zr₁-_xCe_xSiO₄. J. Nucl. Mater., 2019,514:276-283.
[24]	LU X, SHU X, CHEN S ,et al. Heavy-ion irradiation effects on U₃O₈ incorporated Gd₂Zr₂O₇ waste forms. J Hazard Mater., 2018,357:424-430.
[25]	张魁宝, 冠军, 尹丹 , 等. 钙钛锆石的自蔓延高温合成与热力学分析. 原子能科学技术, 2016,50(3):418-423.
[26]	HUANG Y, ZHANG H, ZHOU X ,et al. Synthesis and microstructure of fluorapatite-type Ca_10-2_xSm_xNa_x(PO₄)₆F₂ solid solutions for immobilization of trivalent minor actinide. J Nucl. Mater., 2017,485:105-112.
[27]	YANG J W, TANG B L, LUO S G . Immobilization of simulated actinides in pyrochlore-rich synroc. Journal of Nuclear & Radiochemistry, 2000,22(3):178-183.
[28]	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. 中国原子能科学研究院年报, 2004,26(2):65-70.
[29]	朱鑫璋, 罗上庚, 汤宝龙 , 等. 富钙钛锆石型人造岩石固化模拟锕系废物研究(Ⅰ). 核科学与工程, 1999(2):182-186.
[30]	周慧, 张传智, 李宝军 , 等. 人造岩石固化模拟锝核素废物研究[C]// 第七届全国核化学与放射化学学术讨论会论文摘要集. 2005.
[31]	ZHAO X F, TENG Y C, YANG H ,et al. Comparison of microstructure and chemical durability of Ce_0.9Gd_0.1PO₄ ceramics prepared by hot-press and pressureless sintering. Ceram Int., 2015,41(9):11062-11068.
[32]	TU H, DUAN T, DING Y ,et al. Preparation of zircon-matrix material for dealing with high-level radioactive waste with microwave. Mater Lett., 2014,131:171-173.
[33]	BARINOVA T V, PODBOLOTOV K B, BOROVINSKAYA I P ,et al. Self-propagating high-temperature synthesis of ceramic matrices for immobilization of actinide-containing wastes. Radiochemistry, 2014,56(5):554-559.
[34]	WANG L, SHUA X Y, YIA F C ,et al. Rapid fabrication and phase transition of Nd and Ce co-doped Gd₂Zr₂O₇ ceramics by SPS. J Eur. Ceram. Soc., 2018,38(7):2863-2870.
[35]	LIU X F, NINA F, MARKUS A . Salt melt synthesis of ceramics, semiconductors and carbon nanostructures. Chem. Soc. Rev., 2013,42:8237-8265.
[36]	APURV D, ROBERT V, OLIVIER G ,et al. Molten salt shielded synthesis of oxidation prone materials in air. Nat Mater., 2019,18:465-470.
[37]	LI Y B, SHAO H, LIN Z F ,et al. A general Lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte. Nat Mater., 2020, DOI: 10.1038/ s41563-020-0657-0.
[38]	HU Z M, XIAO X, JIN H Y ,et al. Rapid mass production of two-dimensional metal oxides and hydroxides. via the molten salts method. Nat Commun., 2017,8:15630-15638.
[39]	WU Y J, HONG R Y, WANG L S ,et al. Molten-salt synthesis and characterization of Bi-substituted yttrium garnet nanoparticles. J Alloys Compd., 2009,481(1-2):96-99.
[40]	MATTHEW R . GILBERT. Molten salt synthesis of titanate pyrochlore waste-forms. Ceram. Int., 2016,42(4):5263-5270.
[41]	HAND M L, STENNETT M C, HYATT N C . Rapid low temperature synthesis of a titanate pyrochlore by molten salt mediated reaction. J. Euro. Ceram. Soc., 2012,32(12):3211-3219.
[42]	ADEL M, STEPHANIE S, NICOLAS C ,et al. Coffinite, USiO₄, is abundant in nature: so why is it so difficult to synthesize. Inorg Chem., 2015,54(14):6687-6696.
[43]	WEBER W J . Self-radiation damage and recovery in Pu-doped zircon. Radiat. Eff. Defec. S, 1991,115(4):341-349.
[44]	BURAKOV B E, ANDERSON E B, ROVSHA V S , et al. Synthesis of Zircon for Immobilization of Actinides. MRS Proceedings: Cambridge University Press, 1995,412:33.
[45]	SZENKNECT S, COSTIN D T, CLAVIER N ,et al. From uranothorites to coffinite: a solid solution route to the thermodynamic properties of USiO₄. Inorg Chem., 2013,52(12):6957-6968.
[46]	PROUST V, JEANNIN R, WHITE F D ,et al. Tailored perovskite waste forms for plutonium trapping. Inorg Chem., 2019,58(5):3026-3032.
[47]	DING Y, DAN H, LI J J ,et al. Structure evolution and aqueous durability of the Nd₂O₃-CeO₂-ZrO₂-SiO₂ system synthesized by hydrothermal-assisted Sol-Gel route: a potential route for preparing ceramics waste forms. J Nucl. Mater., 2019,519:217-228.
[48]	WANG C, PING W, BAI Q ,et al. A general method to synthesize and sinter bulk ceramics in seconds. Science, 2020,368:521-526.
[49]	LU F, YAO T, XU J ,et al. Facile low temperature solid state synthesis of iodoapatite by high-energy ball milling. RSC Advances, 2014,4(73):38718.
[50]	CAO C, CHONG S, THIRION L ,et al. Wet chemical synthesis of apatite-based waste forms-a novel room temperature method for the immobilization of radioactive iodine. J Mater. Chem. A, 2017,5(27):14331-14342.
[51]	HASSAN M U, RYU H J . Cold sintering and durability of iodate- substituted calcium hydroxyapatite (IO-HAp) for the immobilization of radioiodine. J. Nucl. Mater., 2019,514:84-89.
[52]	YANG J H, PARK H S, AHN D H ,et al. Glass composite waste forms for iodine confined in bismuth-embedded SBA-15. J Nucl. Mater., 2016,480:150-158.
[53]	MINERVINI L, GRIMES R W, SICKAFUS K E ,et al. Disorder in pyrochlore oxides. J. Am. Ceram. Soc., 2004,83(8):1873-1878.
[54]	LIAN J, HELEAN K B, KENNEDY B J ,et al. Effect of structure and thermodynamic stability on the response of lanthanide stannate pyrochlores to ion beam irradiation. J. Phys. Chem. B, 2006,110(5):2343-2350.
[55]	TU H, DUAN T, DING Y, LU X R ,et al. Phase and micro- structural evolutions of the CeO₂-ZrO₂-SiO₂ system synthesized by the sol-gel process. Ceram. Int., 2015,6(41):8046-8050.
[56]	DING Y, LONG X G, PENG S M ,et al. Phase evolution and chemical durability of Nd-doped zircon ceramics designed to immobilize trivalent actinides. Ceram. Int., 2015,487:279-304.
[57]	CHAPMAN N A , MCKINLEY. The geological disposal of nuclear waste. London: Wiley&Sons, 1999.
[58]	STRACHAN D, TURCOTTE R, BARNES B . MCC-1: A standard leach test for nuclear waste forms. Nucl. Technol., 1982,56(2):306-312.
[59]	JANTZEN C M, BIBLER N E, BEAM D C , et al. Nuclear waste glass product consistency test (PCT): Version 7.0. Revision 3. Technical Report, Westinghouse Savannah River Co., Aiken, SC(United States), 1994.
[60]	SINGH D, MANDALIKA V, PARULEKAR S ,et al. Magnesium potassium phosphate ceramic for ⁹⁹Tc immobilization. J. Nucl. Mater., 2006,348(3):272-282.
[61]	GRIFFITH C S, SEBESTA F, HANNA J V ,et al. Tungsten bronze- based nuclear waste form ceramics. Part 2: Conversion of granular microporous tungstate-polyacrylonitrile (PAN) composite adsorbents to leach resistant ceramics. J. Nucl. Mater., 2006,358(2/3):151-163.
[62]	FAN L, SHU X, LU X ,et al. Phase structure and aqueous stability of TRPO waste incorporation into Gd₂Zr₂O₇ pyrochlore. Ceram. Int., 2015,41(9):11741-11747.
[63]	LI S Y, LIU J, YANG X ,et al. Effect of phase evolution and acidity on the chemical stability of Zr₁-_xNd_xSiO₄-_x_/2 ceramics. Ceram. Int., 2019,45(3):3052-3058.
[64]	NIKOLAEVA E V, BURAKOV B E . Investigation of Pu-doped ceramics using modified MCC-1 leach test. Mater. Res. Soc. Symp. Proc., 2002,713:429-432.
[65]	WEBER W J, WANG L, HESS N J ,et al. Radiation effects in nuclear waste materials. OSTI Tech. Rep., 1998,32(1-4):453-454.
[66]	LI Y H, WANG Y Q, VALDEZJ A ,et al. Swelling efects in Y₂Ti₂O₇ pyrochlore irradiated with 400 keV Ne ²+ ions. Nucl. Instrum. Meth. B, 2012,274:182-187.
[67]	LI Y H, WANG Y Q, XU C P ,et al. Microstructural evolution of the pyrochlore compound Er₂Ti₂O₇ induced by light ion irradiations. Nucl. Instrum. Meth. B, 2012,286:218-222.
[68]	SICKAFUS K E, GRIMES R W, VALDEZJ A ,et al. Radiation induced amorphization resistance and radiation tolerance in structurally related oxides. Nat. Mater., 2007,6(3):217-223.
[69]	UTSUNOMIYA S, YUDINTSEV S, EWING R . Radiation effects in ferrate garnet. J. Nucl. Mater., 2005,336(2/3):251-260.
[70]	DING Y, JIANG Z D, LI Y J ,et al. Effect of alpha-particles irradIation on the phase evolution and chemical stability of Nd-doped zircon ceramics. J. Alloys Compd., 2017,729:483-491.
[71]	YANG X Y, WANG S A, LU Y ,et al. Structures and energetics of point defects with charge states in zircon: a first-principles study. J. Alloys Compd., 2018,759:60-69.
[72]	FINCH R J, HANCHAR J M . Structure and chemistry of zircon and zircon-group minerals. Rev. Miner. Geochem., 2003,53:1-25.
[73]	GALUSKINA I O, GALUSKIN E V, ARMBRUSTER T , et al. Bitikleite-(SnAl) and bitikleite-, 2010,95(7):959-967.
[74]	卢海萍, 王汝成, 陆现彩 . 锆石的结构与化学稳定性: 核废料处置矿物类比物研究. 地学前缘, 2003,10(2):403-409.

SYNROC	Component mass fraction/%							Waste package capacity/%
SYNROC	TiO₂	UO₂	ZrO₂	Al₂O₃	SiO₂	BaO	CaO	Waste package capacity/%
SYNROC-B	74.1	-	6.6	5.4	-	5.6	11.0	-
SYNROC-C	57.1	-	5.4	4.4	-	4.4	8.9	30.0
SYNROC-D	18.8	-	6.6	-	6.6	-	5.3	62.7~65.0
SYNROC-E	87.6	-	3.0	-	-	-	2.2	7.0
SYNROC-F	40.6	47.6	-	0.9	1.1	9.5	-	50.0

SYNROC	Component mass fraction/%							Waste package capacity/%
SYNROC	TiO₂	UO₂	ZrO₂	Al₂O₃	SiO₂	BaO	CaO	Waste package capacity/%
SYNROC-B	74.1	-	6.6	5.4	-	5.6	11.0	-
SYNROC-C	57.1	-	5.4	4.4	-	4.4	8.9	30.0
SYNROC-D	18.8	-	6.6	-	6.6	-	5.3	62.7~65.0
SYNROC-E	87.6	-	3.0	-	-	-	2.2	7.0
SYNROC-F	40.6	47.6	-	0.9	1.1	9.5	-	50.0

Irradiation method	Experimental program	Advantage	Disadvantage
Ion irradiation	Heavy ion beam bombardment	Irradiation damage at low level	Suppress vacancy defects
Electron irradiation	Accelerated voltage induction	Observe defect formation	Complex and expensive equipment
Neutron irradiation	Reactor irradiation	Large dosage, short time	Difficult to control temperature and dosage

Irradiation method	Experimental program	Advantage	Disadvantage
Ion irradiation	Heavy ion beam bombardment	Irradiation damage at low level	Suppress vacancy defects
Electron irradiation	Accelerated voltage induction	Observe defect formation	Complex and expensive equipment
Neutron irradiation	Reactor irradiation	Large dosage, short time	Difficult to control temperature and dosage

SYNROC	Typical components	Density /(g·cm^-3)	Strength	Long-term stability	Package capacity/wt%	Thermal conductivity /(W·m^-1·℃^-1)	Leaching rate /(g·cm^-2·d^-1)
Calcined product	CaF₂ Al₂O₃ ZrO₂	1.0-1.7	Powder	Unstable	High	0.13-0.20	0.1-10
Borosilicate glass	SiO₂ B₂O₃ Na₂O Al₂O₃	2.5-2.8	Hard and brittle	Yellow phase is formed, and there is a tendency to crystallize	15-30	1.00-1.50	10^-6-10^-4
Phosphate glass	P₂O₅ Al₂O₃ Na₂O	2.5-3.0	Hard and brittle	Large tendency to crystallize	15-30	1.00-1.50	10^-5-10^-3
Synroc	TiO₂ ZrO₂ CaO Al₂O₃ BaO	4.0-5.8	Hard	Stable	15-30	2.50-3.50	10^-8-10^-5