4 Dec (NucNet): France’s Institut de Radioprotection et de Sûreté Nucléaire (IRSN) has announced a new research programme to investigate the ageing of concrete in nuclear reactor containment buildings.
IRSN said the project, named Odoba, aims to develop a predictive tool to estimate the durability of reactor containment buildings in order to determine their lifetime.
IRSN, an independent research agency which reports to ministers and offers technical support to the French nuclear regulator ASN (Autorité de Sûreté Nucléaire), said the experimental part of the project will involve the construction of buildings using concrete similar to that used in the containments of French nuclear reactors. The structures will be subjected to an accelerated ageing process designed to simulate several decades of ageing of the materials.
Bernard Chaumont, deputy director for safety research at IRSN, told NucNet these “massive structures” will be built at the French Alternative Energies and Atomic Energy Commission (Commissariat à l'énergie atomique et aux énergies alternatives; CEA) research centre at Cadarache, southern France.
Several auxiliary buildings and a platform to support the structures will be built in 2015. The first test structures are also expected to be built in 2015, Mr Chaumont said.
Mr Chaumont said the experiments will also include small-scale tests and modelling to perform calculations for real structures. These experiments will take place at various academic institutions.
The project will benefit from scientific cooperation with the French and foreign nuclear industries and with specialised R&D organisations, IRSN said.
IRSN is also instigating “a discussion at the national and international levels” to find partners for the project. Possible partners include Belgium’s BelV, a subsidiary of the Federal Agency for Nuclear Control, and the US Nuclear Regulatory Commission, Mr Chaumont said.
IRSN said the project will run parallel to the assessment of plans by Electricité de France (EDF), France’s nuclear power station operator, to extend the operational lifetime of reactors in the French fleet beyond their design-based lifetime of 40 years.
The Odoba project will provide IRSN with independent tools for the assessment of licensee safety reports. Results will be produced in line with IRSN's needs for the analysis of lifetime extension safety reviews for French reactors. The first results are expected in 2018.
The project is expected to end in 2025 and will cost about €1 million (about US$1.25 million) a year.
The reactor containment building plays a crucial role in the event of an accident. The ageing of materials, such as corrosion of the metal rebar and cement swelling, can degrade the containment’s mechanical strength or leak-tightness, resulting in cracking and jeopardising its capabilities, IRSN said.
France has 58 commercially operational nuclear reactors, many of which came online in the late 1970s and early 1980s.
