In situ experiments on the performance of near-field for nuclear waste repository at KURT

2012 ◽  
Vol 252 ◽  
pp. 278-288 ◽  
Author(s):  
Won-Jin Cho ◽  
Jin-Sub Kim ◽  
Changsoo Lee ◽  
Sangki Kwon ◽  
Jong-Won Choi
Keyword(s):  
Nuclear Waste ◽  
Near Field ◽  
Nuclear Waste Repository ◽  
In Situ Experiments ◽  
Waste Repository

scholarly journals Radiation Effects on Materials in the Near-Field of a Nuclear Waste Repository

2000 ◽  
Vol 663 ◽  
Author(s):  
B.X. Gu ◽  
L.M. Wang ◽  
S.X. Wang ◽  
R.C. Ewing
Keyword(s):  
Ion Exchange ◽  
Nuclear Waste ◽  
Radiation Effects ◽  
Ion Beam ◽  
Near Field ◽  
Energetic Electron ◽  
Layered Silicates ◽  
Nuclear Waste Repository ◽  
Layer Spacing ◽  
Waste Repository

ABSTRACTThe long-term radiation effects on materials in the near-field of a nuclear waste repository have been evaluated using accelerated laboratory experiments with energetic electron or ion beam irradiation. The materials studied include: zeolites, layered silicates (smectite clay and mica), as well as crystalline silicotitanate (CST) which is an important ion exchange material for the chemical separation of high-level liquid radioactive wastes.In situ transmission electron microscopy (TEM) during irradiation by energetic electrons and ions has shown that all of the studied materials are susceptible to irradiation-induced amorphization. At room temperature, complete amorphization was observed after ionizing doses of 1010 ∼ 1012 Gy or displacement doses on the order of 0.1 dpa (equivalent to doses received in 400-1,000 years for a high-loading nuclear waste form). Amorphization may be preceded or accompanied by dehydration, layer spacing reduction and gas bubble formation. In the case of zeolites, CST and some layered silicates, radiation effects are significantly enhanced at higher temperatures. Our experiments have shown that amorphization or even partial amorphization will cause a dramatic reduction in ion exchange and sorption/desorption capacities for radionuclides, such as Cs and Sr. Because the near-field or chemical processing materials (e.g. zeolites or CST) will receive a substantial radiation dose after they have incorporated radionuclides, our results suggest that radiation effects may, in some cases, retard the release of sorbed or ion-exchanged radionuclides.

scholarly journals Synthesis of Calcium Monouranate Particles via an Aqueous Route

MRS Advances ◽  
2016 ◽  
Vol 1 (62) ◽  
pp. 4123-4129 ◽  
Author(s):  
Weixuan Ding ◽  
Johannes A. Botha ◽  
Bruce C. Hanson ◽  
Ian T. Burke
Keyword(s):  
Nuclear Waste ◽  
Sol Gel ◽  
Local Solution ◽  
Nuclear Waste Repository ◽  
Thermal Curing ◽  
Calcium Loading ◽  
Precipitation Type ◽  
In Situ Formation ◽  
Waste Repository

ABSTRACTLarge stores of unstable waste uranic materials such as fluorides or nitrates exist internationally due to legacy civil nuclear enrichment activities. Conversion of these uranic materials to layered metal uranates prior to disposal is possible via aqueous quench - precipitation type reactions. Previous studies1 have shown facile in-situ formation of geologically persistent and labile uranate colloids2 under simulated nuclear waste repository conditions, though the effects of local solution metal-uranium ratios on uranate stoichiometry have yet to be covered. This affects our understanding of how key radionuclides present in repository porewaters such as strontium or caesium may be sequestered in these uranate structures. In this work, we demonstrate a synthesis reaction for calcium monouranate particles via rapid anhydrous curing of a sol-gel. We present some results showing aqueous nucleation of uranate nanoparticles and their phase transformations during thermal curing as well as the effects of solution phase calcium loading on uranate phase purity in the cured particles.

Implications of rock structure on the performance in the near field of a nuclear waste repository

1998 ◽  
Vol 49 (3-4) ◽  
pp. 195-200 ◽  
Author(s):  
Johan Andersson ◽  
Peter Robinson ◽  
Michael Impey
Keyword(s):  
Nuclear Waste ◽  
Near Field ◽  
Nuclear Waste Repository ◽  
Rock Structure ◽  
Waste Repository

A double-layered model for near-field temperature in a nuclear waste repository

2021 ◽  
Vol 133 ◽  
pp. 103646
Author(s):  
Yao Xue ◽  
De'an Sun ◽  
Lei Wang ◽  
Yongfu Xu
Keyword(s):  
Nuclear Waste ◽  
Near Field ◽  
Nuclear Waste Repository ◽  
Layered Model ◽  
Field Temperature ◽  
Waste Repository
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