The Relative Radiation Resistance of Zirconolite, Pyrochlore, and Perovskite to 1.5 MeV Kr+ Ions

1997 ◽  
Vol 506 ◽  
Author(s):  
Katherine L. Smith ◽  
Nestor J. Zaluzec ◽  
Gregory R. Lumpkin
Keyword(s):  
Risk Assessment ◽  
Rare Earth ◽  
Radioactive Waste ◽  
Rare Earth Elements ◽  
Radiation Damage ◽  
Radiation Resistance ◽  
Predictive Modelling ◽  
High Level Radioactive Waste ◽  
High Level

ABSTRACTZirconolite (CaZrTi2O7), pyrochlore (vIIIA2VIB2IVx6y) and perovskite (CaTiO3) are candidate phases for the immobilisation of rare earth elements (REEs) and actinides (ACTs) in various high level radioactive waste (HLW) forms [1]. The effect of radiation damage on the structure and consequently on the durability of these phases is important to predictive modelling of their behaviour in the repository environment and risk assessment

TEM Study of Neutron Irradiated Synroc

1997 ◽  
Vol 506 ◽  
Author(s):  
Katherine L. Smith ◽  
Mark G. Blackford ◽  
Gregory R. Lumpkin
Keyword(s):  
Risk Assessment ◽  
Radioactive Waste ◽  
Radiation Damage ◽  
Alpha Particle ◽  
Predictive Modelling ◽  
High Level Radioactive Waste ◽  
Particle Damage ◽  
High Level ◽  
Over Time ◽  
Titanate Ceramic

ABSTRACTSynroc is a candidate waste form for the immobilisation of high level radioactive waste (HLW)[1]. It is polyphase titanate ceramic principally comprised of zirconolite, hollandite perovskite and rutile (nominally CaZrTi2O7, (BaxCsy)[(Ti3+, Al)2x+y(Ti4+)8−2x−y]O16), CaTiO3 and TiO2 respectively). Waste species substitute into the three former phases. In particular, actinides (ACTs) substitute onto the Ca and Zr sites in zirconolite and the Ca site in perovskite. Consequently over time, these phases will suffer alpha-recoil and alpha particle damage while hollandite and rutile will suffer alpha particle damage. The effect of radiation damage on the structure and consequently on the durability of Synroc's constituent phases is important to predictive modelling of Synroc's behaviour in the repository environment and risk assessment.

scholarly journals Magnesium Potassium Phosphate Compound for Immobilization of Radioactive Waste Containing Actinide and Rare Earth Elements

2018 ◽  
Author(s):  
Sergey E. Vinokurov ◽  
Svetlana A. Kulikova ◽  
Boris F. Myasoedov
Keyword(s):  
Rare Earth ◽  
Radioactive Waste ◽  
Rare Earth Elements ◽  
Liquid Radioactive Waste ◽  
Hydrolytic Stability ◽  
Research Work ◽  
Dynamic Test ◽  
Potassium Phosphate ◽  
High Level Waste ◽  
High Level

The problem of effective immobilization of liquid radioactive waste (LRW) is key to the successful development of nuclear energy. The possibility of using magnesium potassium phosphate (MKP) compound for LRW immobilization on the example of nitric acid solutions containing actinides and rare earth elements (REE), including high level waste (HLW) surrogate solution is considered in the research work. Under the study of phase composition and structure of the MKP compounds obtained by the XRD and SEM methods, it was established that the compounds are composed of crystalline phases - analogues of natural phosphate minerals (struvite, metaankoleite). The hydrolytic stability of the compounds was determined according to the semi-dynamic test GOST R 52126-2003. Low leaching rates of radionuclides from the compound are established, including a differential leaching rate of 239Pu and 241Am - 3.5 × 10-7 and 5.3 × 10-7 g/(cm2∙day). As a result of the research work it was concluded that the MKP compound is promising for LRW immobilization and can become an alternative material combining the advantages of easy implementation of the technology like cementation and the high physical and chemical stability corresponding to a glass-like compound.

Immobilization of High Level Nuclear Reactor Wastes in Synroc: A Current Appraisal

1981 ◽  
Vol 6 ◽  
Author(s):  
V.M. Oversby ◽  
A.E. Ringwood
Keyword(s):  
Radioactive Waste ◽  
Radiation Damage ◽  
Single Phase ◽  
Low Dose ◽  
Nuclear Reactor ◽  
Natural Mineral ◽  
High Level Radioactive Waste ◽  
High Level ◽  
A Current

ABSTRACTResults are presented for leach testing at 95°C and 200°C of SYNROC containing 9% and 20% simulated high level radioactive waste, synthetic hollandite and pervoskite samples, and natural zirconolite and pervoskite samples. Single phase synthetic minerals show much higher leach rates than natural mineral samples and polyphase SYNROC samples. Natural zirconolite samples with low radiation damage have leach rates at 200°C based on U which are identical to those measured on SYNROC samples. Natural zirconolites with very large accumulated α dose and radiation damage have leach rates at 200°C which are only 5 times higher than those of low dose samples.

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