Upstream cycle
The Nuclear Fuel Cycle - General Introduction

New fuel is the end product of upstream cycle operations. These first involve the preparation of the raw material, based on ²³⁵U and ²³⁸U for light water reactors, and then the manufacture of the fuel assembly.

The long-term supply of natural uranium is ensured by contracts whose primary objective is to guarantee its security. In 2012, EDF and Areva signed two contracts for the supply of around 30,000 t over the period 2014-2035.

The preparation of the raw material involves the following successive stages:

• extraction of uranium ore from underground mines, open-pit quarries or by leaching ;

• concentration of the U_nat from the ore (which often contains less than 1% uranium) by chemical means, on the extraction site itself, resulting in yellow cake containing 60 to 70% uranium ;

• conversion (fluorination)...