Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Commissariat a L'energie Atomique

Jacques De Sanoit

Charles Madic

Emmanuel Scorsone

Raphael Kiran

Christine Mer-Calfati

Michal Pomorski

Emilie Vanhove

Raphaël Kiran

A method for electrochemically activating a doped diamond electrode by bringing the electrode into contact with an aqueous solution containing an electrolyte and applying at least one electrical pulse to the electrode. This method may be used to restore the electrochemical reactivity of a doped diamond-based electrode, the activation of the electrode in some cases possibly being done in the same aqueous solution containing an electrolyte in which the electrode lost its electrochemical reactivity.

Method of activating a doped diamond electrode

An in situ method for detecting alpha particles contained in a liquid medium, which uses a system which includes a counter-electrode and an alpha particle detector including a substrate made of an intrinsic semiconductor material sandwiched between two electrical contacts, wherein the contact intended to be in contact with the liquid medium is made of boron-doped diamond. By forming a particular electrolyteand by causing a current to flow between counter-electrode and the boron-doped diamond contact in contact with the liquid medium, actinides or polonium present in the liquid medium may be concentrated on the boron-doped diamond contact, and by this means the detection limit of the alpha emitters may be lowered.

Detection method using an electrochemically-assisted alpha detector for nuclear measurement in a liquid medium

The present invention relates to a process for activating a diamond-based electrode, which includes a step consisting in subjecting, in the presence of an aqueous solution containing an ionic electrolyte, said electrode to an alternately cathodic and anodic polarization potential, of increasing amplitude so as to obtain an anodic and cathodic current density of between 10 &#x3bc;A/cmand 1 mA/cm. The present invention also relates to a diamond-based electrode activated by said process and to the uses thereof.

Process for activating a diamond-based electrode, electrode thus obtained and uses thereof

The invention relates to an ammonium plutonate uranate, its preparation process and its use for producing the mixed oxide (U,Pu)O.sub.2. The ammonium plutonate uranate of formula [Cu,Pu)O.sub.3 ].sub.2 [NH.sub.3 ].sub.x [H.sub.2 O].sub.y in which x and y have a value from 0 to 5 with x+y=5, is prepared by neutralization with ammonia of an aqueous solution of uranium VI and plutonium VI salts, e.g. uranyl and plutonyl nitrates. This solution can be prepared by oxidizing a solution of plutonium IV and uranyl nitrate. By calcining under a reducing atmosphere the ammonium plutonate uranate precipitate formed, a mixed oxide (U,Pu)O.sub.2 is obtained having a solubility in 11N HN O.sub.3 without fluoride of at least 99.9%.

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Rungis, France

Jacques De Sanoit