NEA Cabri Water Loop Project

The CABRI Water-Loop Project is investigating the ability of high burn-up fuel to withstand sharp power peaks that can occur in power reactors due to rapid reactivity insertion in the core. These are referred to as reactivity-initiated accidents (RIA). The project stems from previous Japanese and French tests conducted on high burn-up pressurized-water reactor (PWR) fuel that, in a few instances, exhibited failure at relatively moderate energy deposition levels. The CABRI project aims to extend the database for high burn-up fuel performance in RIA conditions and, more importantly, perform relevant tests in coolant conditions representative of PWRs.

The project began in March 2000 and intends to run until 2021 (this is a further extension from 2015 approval of which is in progress). The experimental work will be carried out by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in Cadarache, France, where the CABRI reactor is located. Programme execution may also involve laboratories in partner organizations (e.g., in relation to fuel characterisation or post-irradiation examinations).

Twelve tests are proposed (two of which have been performed) as a basis for co-operation among the CABRI Water Loop Project partners: these experiments include R&D tests combined with suitable tests to validate the extrapolation to a broad spectrum of reactor cases. The experimental programme is reviewed by the project steering bodies and consists (in principle) of the following series of tests:

The S0 tests were carried out in 2003 in the original sodium loop using fuel with very high burn-up and modern cladding materials: subjected to energy injection beyond what is expected for power-reactor cases, the two test fuel rods did not fail during these tests. Post-irradiation examinations involving destructive examinations of the S0 rods were undertaken in 2004 and investigated, in particular, the effect of hydrogen on cladding properties. The planning of future tests continues with the aim of developing a consistent set of objectives and identifying suitable fuel specimens. Progress on the refurbishment of the CABRI test facility and the water-loop conversion (requiring several years) is complete. Currently (mid-2015), a first test in the water loop is planned to be performed by the end of 2016 and, subsequently, the operator will be in a position to perform 2 tests per year where rods for the first five tests are already prepared.

The CABRI tests are complemented by supplementary pulse-irradiation tests performed in JAEA’s Nuclear Safety Research Reactor (NSRR), e.g., Fuketa et al., (2006), J. Nucl. Sci. Technol. 43(9).

Project data

The data abstract is public.

Participating organisations

Project period

January 2000 to December 2015


~ EUR 74 million

Related links


Martin Kissane:

Last reviewed: 20 July 2015