Publications by authors named "Donald M Noronha"

Recovery of plutonium from aqueous carbonate waste solutions generated during the reprocessing of spent nuclear fuel is a key concern for sustainable nuclear energy programmes and the remediation of radioactive waste. Reported methods proceed through secondary waste generation caused by acidification of carbonate waste and make the recovery process cumbersome. Herein, we report a simple method for the recovery of Pu as solid PuO powder from carbonate waste solution in a two-step process.

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Interfacial coupled chemical reaction between U(iv) (formed at the electrode surface) and Pu(iv) (diffuses from the bulk towards the electrode) regenerates U(vi) at the electrode-solution interface and causes enhancement in the U(vi) reduction current, thus creating problems in the simultaneous voltammetric determination of U and Pu. Despite such interference between U(iv) and Pu(iv), the simultaneous voltammetric determination of U and Pu in FBTR Mark-1 fuel samples in sulfuric acid (1 M HSO) on a poly(3,4-ethylenedioxythiophene) (PEDOT)-poly(styrenesulfonate) (PSS)-modified glassy-carbon (GC) electrode (PEDOT-PSS/GC) has been reported. However, the reported method is applicable only for FBTR mark-1 fuel samples, in which the ratio [Pu]/[U] > 2 is always maintained.

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Uranium (U) and plutonium (Pu) contents in nuclear materials must be maintained to a definite level in order to get the desired performance of the fuel inside the reactor. Therefore, high accuracy and precision is an essential criterion for the determination of U and Pu. We already reported the voltammetric determination of Pu in the presence of U in fast-breeder-test-reactor (FBTR) fuel samples, but interfacial, coupled chemical reactions between U(IV) and Pu(IV) enhance the peak-current density of U(VI) reduction and thus make voltammetry unsuitable for the quantitative determination of U in the presence of Pu.

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A monoamide, N,N'-dioctyl, α-hydroxy acetamide, shows unusual extraction properties towards trivalent lanthanide and actinide ions above 3 M HNO3. The extracted ions could be quantitatively back extracted using 0.5 M HNO3.

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