Differential Lead Retention in Zircons: Implications for Nuclear Waste Containment

Gentry, Robert V.; Sworski, Thomas J.; McKown, H.S.; Smith, David H.; Eby, R.E.; Christie, W. H.

doi:10.1126/science.216.4543.296

Cited by 39 publications

(9 citation statements)

References 6 publications

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“…The propensity to incorporate actinides and its durability have lead to the suggestion that zircon be used to immobilize actinides (36)(37)(38). Based on the ability of natural zircon to retain Pb, Gentry et al (39) suggested that materials, like zircon, could effectively retain radioactive waste. This early suggestion was prescient but did not evaluate the extent of solid-solution of actinides in zircon and did not consider the much greater radiation damage that would occur in such a radioactive waste form (40).…”

Section: Zircon As An Actinide Waste Formmentioning

confidence: 99%

Nuclear waste forms for actinides

Ewing

1999

Proc. Natl. Acad. Sci. U.S.A.

406

217

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The disposition of actinides, most recently 239 Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239 Pu and 237 Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The ''mineralogic approach'' is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium.

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Section: Zircon As An Actinide Waste Formmentioning

confidence: 99%

Nuclear waste forms for actinides

Ewing

1999

Proc. Natl. Acad. Sci. U.S.A.

406

217

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“…1, The zircon structure (after Speer 1982) ide-host phase (Harker and Flintoff 1984;Ewing 1981); the a-decay event damage in natural zircons of great age has been compared to the damage observed in Pu-doped zircon (Weber 1990) and ionbeam irradiated zircon (Wang and Ewing 1992;Wang et al 1993). Radionuclide loss from nuclear waste forms has been evaluated using models for Pb-loss from zircon (Gentry et al 1984;Ludwig et al 1984). Finally, damaged regions in ion beam irradiated zircons can be used to study track formation (Bursill and Braunshausen 1990) and to make optic wave guides in zircon (Babsail et al 1991).…”

Section: Introductionmentioning

confidence: 99%

Energetics of radiation damage in natural zircon (ZrSiO4)

1994

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Abstract. Transposed temperature drop calorimetry at 1000 ~ was performed on natural zircons (ZrSiO4) from Sri Lanka that were partially to completely metamict due to e-decay event damage (0.06 to 11.7x l02s e-decay events/mg). The enthalpy of annealing at room temperature (AH ..... 1) varies sigmoidally as a function of radiation dose. AH ..... l reaches a saturation plateau at radiation doses greater than 5 x 1015 a-decay events/mg. The annealing of several samples to a crystalline structure with broadened diffraction peaks does not significantly affect the enthalpy of annealing. The large magnitude of the enthalpy of annealing plateau, -59 __ 3 kJ/mol, suggests that the damage to the structure is pervasive on the scale of ~ngstroms, consistent with the loss of mid-range order characteristic of a glass. The energetics are consistent with, but do not require, chemical heterogeneity caused by micro-domains of amorphous SiO2-rich and ZrO2-rich regions in the metamict state.

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“…They publish in, and review papers for standard professional journals. Some even have rather impressive publication records and CV's that are very much worth envying; the work of geophysicist John Baumgarder, for example, is known and respected internationally (Chandler 1997), and physicist Robert Gentry is the principal author of 12 papers in Science and Nature (plus numerous other publications) (Gentry 1967(Gentry , 1968(Gentry , 1970(Gentry , 1971(Gentry , 1974(Gentry , 1978a(Gentry , b, 1992Gentry et al 1973Gentry et al , 1974Gentry et al , 1976Gentry et al , 1982.…”

Section: Resources Of Contemporary 'Radical' Creationismmentioning

confidence: 97%