Development of iron phosphate ceramic waste form to immobilize radioactive waste solution

ABSTRACTIt has been shown that between 10 and 20% of a simulated PW–4b radwaste composition can be incorporated into a single nhase with the NZP (= ‘MaZr2 P3 o12’) structure. By changing the P/Na and Zr/Na molar ratios (i.e., adjusting the crystal chemical model of where each ion is located in the structure) it has been possible to outline a very ‘forgiving’ compositional regime both at the 10% and the 20% waste loading level within which one obtains one ([NZP]) or two ([NZP] and [monazite]) phases. We have also succeeded in substituting Tio2 for Zro2 in making a TiO2-rich [NTP] waste form analogous to the [NZ]] materials.Thus we have succeeded in creating monophasic and diphasic ceramic waste forms which can be sintered below 1000° C. Only preliminary leach data have been obtained at 25° and 300°C, and they place this material with good ceramic forms.

Download Full-text

Generalized Titanate Ceramic Waste Form Developed for Processing Radioactive Waste with Various Compositions

MRS Bulletin ◽

10.1557/mrs2001.169 ◽

2001 ◽

Vol 26 (8) ◽

pp. 597-601

Author(s):

Cora Lind

Keyword(s):

Radioactive Waste ◽

Waste Form ◽

Ceramic Waste ◽

Titanate Ceramic

Download Full-text

Study of Natural Minerals of U-Ryrochlore-Type Structure as Analogues of Plutonium Ceramic Waste-form

MRS Proceedings ◽

10.1557/proc-713-jj2.2 ◽

2002 ◽

Vol 713 ◽

Cited By ~ 1

Author(s):

Roman V. Bogdanov ◽

Yuri F. Batrakov ◽

Elena V. Puchkova ◽

Andrey S. Sergeev ◽

Boris E. Burakov

Keyword(s):

Chemical Shifts ◽

Pyrochlore Structure ◽

Type Structure ◽

Waste Form ◽

X Ray ◽

Ceramic Waste ◽

Natural Minerals ◽

The Us ◽

Pyrochlore Type

ABSTRACTAt present, crystalline ceramic based on titanate pyrochlore, (Ca,Gd,Hf,Pu,U)2Ti2O7, is considered as the US candidate waste form for the immobilization of weapons grade plutonium. Naturally occuring U-bearing minerals with pyrochlore-type structure: hatchettolite, betafite, and ellsworthite, were studied in orders to understand long-term radiation damage effects in Pu ceramic waste forms. Chemical shifts (δ) of U(Lδ1)– and U(Lβ1) – X-ray emission lines were measured by X-ray spectrometry. Calculations were performed on the basis of a two-dimensional δLá1- and δLδ1- correlation diagram. It was shown that 100% of uranium in hatchettolite and, probably, 95-100% of uranium in betafite are in the form of (UO2)2+. formal calculation shows that in ellsworthite only 20% of uranium is in the form of U4+ and 80% of the rest is in the forms of U5+ and U6+. The conversion of the initial U4+ ion originally occurring in the pyrochlore structure of natural minerals to (UO2)2+ due to metamict decay causes a significant increase in uranium mobility.

Download Full-text

A Description of the Ceramic Waste Form Production Process from the Demonstration Phase of the Electrometallurgical Treatment of EBR-II Spent Fuel

Nuclear Technology ◽

10.13182/nt01-a3200 ◽

2001 ◽

Vol 134 (3) ◽

pp. 263-277 ◽

Cited By ~ 28

Author(s):

Michael F. Simpson ◽

K. Michael Goff ◽

Stephen G. Johnson ◽

Kenneth J. Bateman ◽

Terry J. Battisti ◽

...

Keyword(s):

Production Process ◽

Waste Form ◽

Spent Fuel ◽

Ceramic Waste

Download Full-text

Aging Studies of Pu-238 and -239 Containing Calcium Phosphate Ceramic Waste-forms

MRS Proceedings ◽

10.1557/opl.2013.926 ◽

2013 ◽

Vol 1518 ◽

pp. 73-78 ◽

Cited By ~ 1

Author(s):

Shirley K. Fong ◽

Brian L. Metcalfe ◽

Randall D. Scheele ◽

Denis M. Strachan

Keyword(s):

Calcium Phosphate ◽

Accelerated Aging ◽

Waste Form ◽

Calcium Phosphate Ceramic ◽

Ceramic Waste ◽

Waste Forms ◽

Aging Studies ◽

Flow Through ◽

Pyrochemical Reprocessing

ABSTRACTA calcium phosphate ceramic waste-form has been developed at AWE for the immobilisation of chloride containing wastes arising from the pyrochemical reprocessing of plutonium. In order to determine the long term durability of the waste-form, aging trials have been carried out at PNNL. Ceramics were prepared using Pu-239 and -238, these were characterised by PXRD at regular intervals and Single Pass Flow Through (SPFT) tests after approximately 5 yrs.While XRD indicated some loss of crystallinity in the Pu-238 samples after exposure to 2.8 x 1018 α decays, SPFT tests indicated that accelerated aging had not had a detrimental effect on the durability of Pu-238 samples compared to Pu-239 waste-forms.

Download Full-text

The Oak Ridge National Laboratory Hydrofracture Process for the Disposal of Radioactive Waste

MRS Proceedings ◽

10.1557/proc-15-565 ◽

1982 ◽

Vol 15 ◽

Author(s):

Herman Weeren ◽

Earl Mcdaniel

Keyword(s):

Radioactive Waste ◽

National Laboratory ◽

Waste Solution ◽

Oak Ridge ◽

Operational Costs ◽

Disposal Facility ◽

Oak Ridge National Laboratory ◽

Shale Formation ◽

Radionuclide Activity

ABSTRACTThe hydrofracture process is currently being used at Oak Ridge National Laboratory (ORNL) for the permanent disposal of locally generated radioactive waste solutions. In this process, the waste solution is mixed with a blend of cement and other solid additives; the resulting grout is then injected into an impermeable shale formation at a depth of 200 to 300 m (700 to 1000 ft). The grout sets a few hours after completion of the injection, fixing the radioactive waste in the shale formation.Between 1966 and 1979, ORNL has used hydrofracture to dispose of more than 8 million L (2 million gal) of waste grout containing more than 600,000 Ci of radionuclide activity. Calculations show that operational costs are on the order of $0.16/L ($0.60/gal). Construction of a new hydrofracture disposal facility has been completed, and operational injections were initiated in June 1982.

Download Full-text

Progress on Ongoing Waste form HIP projects at ANSTO

MRS Advances ◽

10.1557/adv.2018.328 ◽

2018 ◽

Vol 3 (20) ◽

pp. 1059-1064 ◽

Cited By ~ 1

Author(s):

Eric R. Vance ◽

Dorji T. Chavara ◽

Daniel J. Gregg

Keyword(s):

Spent Nuclear Fuel ◽

Technology Development ◽

Hot Isostatic Pressing ◽

Waste Form ◽

Process Technology ◽

Ceramic Waste ◽

Waste Forms ◽

Produce Glass ◽

Form Development ◽

Year 2000

Abstract:Since the year 2000, Synroc has evolved from the titanate full-ceramic waste forms developed in the late 1970s to a hot isostatic pressing (HIP) technology platform that can be applied to produce glass, glass–ceramic, and ceramic waste forms and where there are distinct advantages over vitrification in terms of, for example, waste loading and suppressing volatile losses. This paper describes recent progress on waste form development for intermediate-level wastes from 99Mo production at ANSTO, spent nuclear fuel, fluoride pyroprocessing wastes and 129I. The microstructures and aqueous dissolution results are presented where applicable. This paper provides perspective on Synroc waste forms and recent process technology development in the nuclear waste management industry.

Download Full-text