Decontamination of Sludgelike Uranium-Bearing Wastes: Decontamination Feasibility Judgment Using Radon Emanation Coefficients and Development of Decontamination Methods

Sasaki, Tomozo; Imamura, Mitsutaka; Gunji, Yasuyoshi; Okuda, Takeshi; Fujiwara, Kenichi; Takai, Masakazu; Arai, Kazuhiro; MORIGAKI, Yoshin

doi:10.3327/jnst.45.464

Cited by 1 publication

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“…This is considered to be due to the partial aggregation of the uranium compounds with CaF 2 and the dissolution of CaF 2 itself. Decontamination of uranium-bearing sludge-like wastes up to the clearance level is difficult because the acid cannot penetrate into the small pores of the sludge where uranium is deposited [23]. However, it appears that this method is effective because the entire sludge is almost completely dissolved (99.8 wt%) in the presence of aluminum.…”

Section: Dissolution Of Caf 2 Sludgementioning

confidence: 99%

Technique for recovering uranium from sludge-like uranium-bearing wastes using hydrochloric acid

Ohashi

Nomura

Tsunashima

et al. 2013

Journal of Nuclear Science and Technology

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Sludge-like uranium-bearing wastes generated from uranium refining and conversion R&D facilities are stored at the Ningyo-toge Environmental Engineering Center of the Japan Atomic Energy Agency. So far, approximately 1500 t of uranium wastes with radioactivity levels exceeding 10,000 Bq/g have been generated. We have proposed an environmentally benign aqueous process for recovering uranium from wastes using hydrochloric acid (HCl). This makes it possible to dispose of the wastes easily, and to reclaim uranium as a resource. In this process, first, the uranium content in the calcium fluoride (CaF 2 ) sludge along with the entire sludge is dissolved almost completely in aqueous solutions containing HCl and aluminum chloride. The uranium species are then recovered as peroxide from the CaF 2 sludge solution. Their characteristics are similar to those specified for uranium ore concentrate. After recovering the uranium content, the uranium concentration in the solution is reduced to below 0.01 mg/L using an iminodiacetic chelating resin. Also, the uranium concentration of the precipitate generated by the neutralization of the barren solution falls below 1 Bq/g.

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Section: Dissolution Of Caf 2 Sludgementioning

confidence: 99%