Das Projekt "Demonstration of explosive dismantling techniques of the biological shield of the Niederaichbach nuclear power plant (KKN)" wird vom Umweltbundesamt gefördert und von Battelle-Institut e.V. durchgeführt. Objective: This project aims at demonstrating explosive dismantling techniques on the biological shield of the nuclear power plant Niederaichbach (KKN), which was operated from 1972 to 1974 and is foreseen to be completely removed. The radioactive inventory of the shield is estimated in the order of 3.7E9 Bq (0.1 Ci). The level of activation is estimated to be in the order of 10 Bq/g, and the associated dose rates in the order of 10 micro Sv/h. Within this contract, blast peeling of the activated concrete from a 30C sector of the biological shield will be performed. This technique will be applied as one of 2 main techniques (hydraulic hammer besides blast peeling) for the dismantling of the whole biological shield of KKN; for this, the licensing authorities have already given their agreement. This demonstration project will be conducted according to the guidelines of the ongoing total dismantling of KKN. In particular, the generation of specific data on costs, working hours and job doses as well as on the amount of created secondary waste is considered as an important objective of this project. This will facilitate the application of this technology and acceptance from the safety point of view in future large-scale decommissioning operations. The project is a follow-up of small-scale work on inactive samples performed jointly under contracts FI1D0011 and FI1D0012. The work programme will be implemented jointly by three main contractors: Battelle Europe e.V./Frankfurt (BE), acting as coordinator, Noell/Würzburg (Noell) and Siemens/KWU (Siemens), as well as Stangenberg, Schnellenbach and Partner (SSP) as sub-contractor. Further cooperation is foreseen with TUV Bayern for the assessment of air filter systems. General Information: WORK PROGRAMME: 1. Preparatory planning and design work for on-site equipment and regulatory requirements (BE, Noell); 1.1. Layout of blasting patterns and of bore holes charging, according to the area of application (BE); 1.2. Design of blasting schemes according to the area of application (BE); 1.3. Definition of blasting area sub containments for the retention of dust, including associated filter systems (Noell, BE); 2. Demonstration blasting on the KKN shield by manual handling (BE, Noell); 2.1. Site preparation for the installation of tools and measuring devices (BE, Noell); 2.2. Assessment and implementation of auxiliary techniques such as bore hole drilling, cutting of the reinforcement by hydraulic shears, use of a hydraulic ram (Noell); 2.3. Main operation and concrete removal, consisting of a sequence of about 10 individual blasts, including pre- and post-blast working (BE, Noell); 2.4. Assessment of blasting performance, with respect to predetermined criteria such as concrete removal rate, safety aspects, integrated doses and generation of secondary waste (BE, Noell); 3. Assessment of dust retention by industrial filter systems with respect to efficiency and safety of handling (Noell, BE); 4. Assessment of ...