The reactor physics group works on the issue of innovative reactor development for future nuclear energy. Concerning nuclear data measurements, the group is at present involved in fission product yield measurements at the Lohengrin spectrometer at ILL. In the early 2000 years, the lab built a slowing-down time spectrometer coupled to a neutron source, creating the PEREN platform (Plateforme d'Etude et de Recherche sur l'Energie Nucléaire) which allowed in particular the access to first data on neutron elastic scattering on carbon and fluor, data of main interest for MSR (Molten Salt Reactor). This platform added a "molten salt" facility in 2005, in order to process fluoride materials, and is the place where bubbling experiments now take place (FFFER), a technique investigated for molten salt reactor as it allows the on-line cleaning of the salt by removing some fission products from the fuel.  This new reactor core concept was the subject of many simulations which contributed to the definition of conditions for exploiting the thorium cycle with good safety and breeding abilities for different neutron energy spectra. The different ways to produce the fissile fuel required for starting breeder reactors, fed afterwards with fertile thorium or uranium 238 fuel (1 ton per GWe.year) were calculated and gave birth to deployment scenarios by the end of the century, taking into account the world situation of energy consumption. Other short term scenarios are also under study.
ADSs (Accelerators Driven Systems), studied for their possible ability to incinerate long-lived and high activity nuclear waste, are the subject of a demonstrator construction project (MYRRHA) led by the SCK-CEN (Belgium). Since the 90's our group works on the issue of on-line reactivity control of an ADS, a crucial issue for the system safety. It was one of the objectives of the MUSE program, completed in 2004, performed at the MASURCA reactor coupled to the pulsed neutron source GENEPI, designed and built by the LPSC. This project led to a new step in the validation of the methodolodgies we investigated, the GUINEVERE project, which consists in coupling the Belgian reactor VENUS (SCK-CEN), turned to a fast neutron reactor, with a new neutron source GENEPI-3C, allowing operation in both continuous and pulsed modes, designed and constructed by a CNRS/IN2P3 collaboration, coordinated by the LPSC. Started in the frame of the EUROTRANS-IP project, this program is still going on in the FREYA project (2011-2016), with additional objectives aiming at preparing the MYRRHA reactor construction.