Objective THE OBJECTIVE OF THIS RESEARCH IS TO STUDY THE LONG-TERM PERFORMANCE OF STRUCTURES COMPRISING NUCLEAR POWER PLANTS. THE TIME PERIOD OF INTEREST FOR THIS STUDY IS 140 YEARS (THIS FIGURE IS BASED ON MAXIMUM PERIODS OF 40 YEARS FOR OPERATION AND 100 YEARS OF STORAGE). PARTICULAR ATTENTION WILL BE GIVEN TO THOSE PARTS OF THE PLANT FOR WHICH LEAK TIGHTNESS AND STRUCTURAL INTEGRITY ARE REQUIRED, BOTH DURING OPERATION AND FOR LONG PERIODS AFTER FINAL SHUTDOWN. THIS RESEARCH WILL BE EXECUTED IN CLOSE COOPERATION WITH TAYLOR WOODROW CONSTRUCTION LTD. THE SPECIFIC AIM OF THIS RESEARCH IS TO INVESTIGATE THE BEHAVIOUR OF COMPLEX COMPOSITE STRUCTURES, TAKING AS A BASIS THE LONG-TERM BEHAVIOUR OF MATERIALS. THE POSSIBLE SUSCEPTIBILITY TO LONG-TERM DAMAGE WILL ALSO BE ASSESSED, AND THE AREAS MOST PRONE TO SUCH DAMAGE WILL BE IDENTIFIED. FURTHER CONSIDERATION WILL BE GIVEN TO THE POSSIBLE INTERACTION BETWEEN SEALING STEEL COMPONENTS (STEEL CONTAINMENTS, STEEL LINERS) AND LOAD BEARING CONCRETE STRUCTURES. THIS BUILDING SURVEY WILL BE CARRIED OUT ON STRUCTURAL ELEMENTS OF ACTUAL PWR STATIONS (E.G. EMSLAND-LINGEN) AND BWR STATIONS (E.G. GUNDREMMINGEN B AND C). CONSIDERATION WILL BE GIVEN TO THE VALIDITY OF THE INVESTIGATIONS FOR RELEVANT STRUCTURES OF OTHER COMMERCIAL NUCLEAR POWER PLANTS IN THE EUROPEAN COMMUNITY. THIS INVESTIGATION WILL INCLUDE THE SHUT-DOWN BWR STATION OF GARIGLIANO IN ITALY. The main elements of reinforced concrete and prestressed concrete structures of reator buildings were investigated concerning their long term performance, a period of about 100 years after decommissioning. As reference plants 2 German nuclear power plants were chosen, one pressurized water reactor (PWR) type and one boiling water reactor BWR type.A survey of the general long term behaviour of the structural elements, and especially of their components, concrete and reinforcement steel, was made. The development of strength and the influence of carbonation on the concrete were evaluated. As far as the reinforcement is concerned, the corrosion mechanism is important.The monitoring procedures that are proposed, depend on the importance and on the range of utilization of the materials under dead load. No severe effect on the stability of the concrete structures of the plants was expected if the durability of anchorage elements or bearings would not last for the regarded time after decommissioning. It is recommended for all inner structural elements and especially those which are located in nonaccessible areas to maintain unchanged carbonation retarding and corrosion retarding climatic conditions. The stability of the reference plants is expected to endure at least 100 years after decommissioning.It is essential to guarantee leak tightness of the steel containment or steel liner and to assure integrity of important structures up to ultimate demolition of the plant. For the 100 year period in question after decommissioning, the type and extent of corrosion damage are discussed for areas classified as potential risk areas and measures to assure enclosure are recommended with monitoring and conservation measures.Long term examinations of silicon sealing materials used in safety related areas were performed. On the basis of the test results and additional literature studies an attempt was made to evaluate the long term suitability of this silicon material as sealing material.Nondestructive tests using the ultrasonic test technique were performed on a component and on calibration blocks in order to detect corrosion in nonaccessible areas. On the basis of these test results it was possible to confirm corrosion in these areas.1. INVESTIGATION ON REINFORCED CONCRETE AND PRESTRESSED CONCRETE STRUCTURES. 1.1. SELECTION OF STRUCTURAL ELEMENTS CONSIDERED IMPORTANT WITH REGARD TO THE INTEGRITY OF LONG-TERM CONTAINMENT. 1.2. LITERATURE STUDY ON MATERIAL BEHAVIOUR COVERING LONG-TERM PROPERTIES. 1.3. ANALYSIS OF THE LONG-TERM BEHAVIOUR OF THE SELECTED STRUCTURAL ELEMENTS. 2. INVESTIGATION OF STEEL CONTAINMENTS. 2.1. SELECTION OF ELEMENTS SUSCEPTIBLE TO DAMAGE, IN PARTICULAR PLASTIC SEALINGS WITH CONCRETE AND STEEL. 2.2. ASSESSMENT OF DAMAGE (STATE OF MATERIAL, TYPES OF CORROSION, FORMATION OF CONDENSED MOISTURE, PERMEABILITY OF THE CONCRETE, ETC.). 2.3. OPTIMIZATION OF ULTRASONIC TESTING TECHNIQUES (ANGULAR SOUND, WEAKENING, CREEP WAVE, ETC.) AND APPLICATION OF THE SELECTED TECHNIQUES TO DECOMMISSIONED NIEDERAICHBACH AND GUNDREMMINGEN I NUCLEAR POWER PLANTS. 3. RECOMMENDATIONS FOR MONITORING AND ENHANCING LONG-TERM INTEGRITY OF REINFORCED AND PRESTRESSED CONCRETE AND FOR ASSESSMENT OF IN-SITU CORROSION OF STEEL ELEMENTS. Fields of science humanitieslanguages and literatureliterature studiesengineering and technologyother engineering and technologiesnuclear engineeringnatural scienceschemical sciencesinorganic chemistrymetalloids Programme(s) FP1-DECOM 2C - Research programme (Euratom) concerning the decommissioning of nuclear installations, 1984-1988 Topic(s) Data not available Call for proposal Data not available Funding Scheme CSC - Cost-sharing contracts Coordinator Zerna, Schnellenberg und Partner GmbH EU contribution No data Address 4630 Bochum Germany See on map Total cost No data Participants (2) Sort alphabetically Sort by EU Contribution Expand all Collapse all Taylor Woodrow Construction Ltd United Kingdom EU contribution No data Address Taywood House 345 Ruislip Road UB1 2QX Southall See on map Links Website Opens in new window Total cost No data Technischer Überwachungsverein Bayern eV Germany EU contribution No data Address Westendstraße 199 80686 München See on map Total cost No data
