Industrial Application of Denitration of HLLW by Means of HCHO

Concentration of HLLW is an interim step between reprocessing and solidification process. The process using denitration by means of HCHO is composed of three main steps: receiving of solutions and feeding, concentration in a kettle type evaporator, and absorption of NOx. This process is operated semi-continuously: concentration is performed at constant level (with denitration and NOx absorption) and evaporator is emptied by batch to the storage. The industrial experience has been gained for nearly 30 years in three reprocessing plants. The safety of the chemical process reaches very high standard thanks to the appropriated operating mode and efficient process control. Only very few incidents have been recorded. No alternative to this process is envisaged today.