Framatome Experience from Recent Nuclear Dismantling Projects in Germany

Abstract

With regard to the operating life of existing Nuclear Power Plants and the related needs for shut-down, modernization or new builds / technologies there is an increasing dismantling market expected worldwide within the next decades. In Germany, based on the nuclear power phase-out decision, the decommissioning of several sites has already started and will be continued in the upcoming years.

German nuclear dismantling projects are basically following a decommissioning strategy from “hot” to “cold” or from the inside to the outside. These concepts enable an early reduction of the radiological inventory. The overall sequence consists of the following main steps:

• Radiological evaluation and characterization of the systems for segmentation and package planning
• Full System Decontamination (FSD)
• Segmentation of the reactor pressure vessel (RPV) internals and packing of pieces into waste containers
• Segmentation of the RPV and packing of segments into waste containers
• Removal of other large components (e.g., steam generator, pressurizer)

The paper reflects Framatome experience from recent German nuclear dismantling projects focusing on the main dismantling activities of nuclear components. It includes some lessons learned gained during decommissioning of boiling water (BWR) and pressurized water reactors (PWR).

Combining and assessing the feedbacks and experience from the individual sub-projects is a valuable asset for optimization. It can exemplarily lead to a shortened overall decommissioning schedule and thus decreased decommissioning costs. Optimization of radiologic characterization, package planning and cutting sequence planning are additional preparatory measures for costs savings. This applies not only for new decommissioning projects but also for legacy waste sites.