Plutonium mass content accurate determination by controlled potential coulometry at CETAMA

S. Picart (1) , Y. Davrain (1) , M. Crozet (1) , D. Roudil (1)

1 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

Controlled-potential coulometry is a method of choice for determining plutonium in solution because it is not related to chemical standards but only to physical parameters such as time and current which can be calibrated very accurately.The method is thus called a primary method and is of great interest for metrology laboratories providing certified reference materials of plutonium. Indeed, it allows to attain high trueness with bias close or below 0.1% on low sample amounts, typically a few milligrams of matter.But, coulometry of high degree of accuracy is still a difficult exercise because every step of the procedure, from sample preparation to the signal integration has to be carefully controlled and optimized.This paper describes the key points of the method and emphasizes on uncertainty budget calculations. This approach will allow us to think over the method and adapt the procedure in order to improve trueness and repeatability for plutonium alone but also to cope with measurement of plutonium in presence of uranium.

Mots clés: plutonium; coulometry; analysis; metrology

Domaines: Physique Nucléaire Expérimentale [nucl-ex]; Physique Nucléaire Théorique [nucl-th]

S. Picart, Y. Davrain, M. Crozet, D. Roudil. Plutonium mass content accurate determination by controlled potential coulometry at CETAMA. Plutonium Futures - The Science 2018, Sep 2018, San Diego, United States. ⟨cea-02339076⟩