Cabri International Project (CIP)
Joint project

The Cabri International Project (CIP) began in March 2000 to study the behaviour of fuel rods, specifically cladding, during a reactivity-initiated accident (RIA) in a pressurised-water reactor (PWR).

CIP investigates the ability of both uranium dioxide (UO2) and mixed-oxide fuel (MOX) PWR fuels to withstand sharp power transients that would arise from rapid reactivity injection in the core, i.e. so-called RIA. The project stems from earlier Japanese and French tests conducted on high burn-up PWR fuel that, in a few instances, exhibited failure at relatively moderate levels of injected energy. CIP aims to extend the database for high burn-up fuel behaviour and, importantly, perform the majority of tests in conditions representative of PWR RIAs. The experimental programme is undertaken by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) at Cadarache, France, where the Cabri facility is located. The programme might also involve partner laboratories relating to fuel characterisation or post-irradiation examinations (PIEs).

CIP partners determine the test conditions where the experimental programme is regularly reviewed by the Technical Advisory Group and the project is overseen by the Steering Committee. CIP comprises twelve tests where the first two tests, CIP0-1 and CIP0-2, have been performed in the original sodium loop of the Cabri facility. The test matrix evolves as CIP progresses but an illustration is provided below.

  • Series S0: two tests, CIP0-1 and CIP0-2 (performed in the original sodium loop).
  • Series S1: two tests to provide a comparison with S0 tests (and pulse width effect).
  • Series S2: two tests on the behaviour of very high burn-up fuel.
  • Series S3: two tests on RIA phenomena and modelling.
  • Series S4: two tests on MOX fuel behaviour.
  • Series S5: two complementary tests to be specified.

In 2002, tests CIP0-1 and CIP0-2 were performed using fuel of very high burn-up with M5 and Zirlo claddings. Destructive PIEs in 2004 investigated, in particular, the effect of hydrogen on cladding properties. Since then, IRSN has been engaged in a programme of conversion to a water loop and substantial upgrading of the facility. Following the loading of new fuel in 2014, in October 2015 the French regulator authorised operation of the refurbished reactor and the first criticalities of the new core were produced a few days later. Low-power tests from October 2015 to June 2016 allowed complete neutronic characterisation of the core. In 2015-16, qualification of the experimental equipment was completed, in particular the imagery and spectroscopy measurement station as well as the hodoscope which recorded its first neutrons; the pressurised-water loop was also qualified at 280°C and 155 bars. In the last quarter of 2016, the new core achieved its first high-power plateaus, i.e. 5-23 MW, which allowed further instrument qualification including the neutron chambers that provide online measurement of reactor power. The final phase of testing was completed in 2017 where this concerned RIA-type power transients and included sixty power pulses of different magnitudes and durations. Authorisation of the CIP-Q test by the French regulator ASN was requested in late May 2017 and granted on 8 Feb. 2018; the CIP-Q test was successfully performed on 16 April 2018. IRSN expects to be in a position to perform two tests per year when rodlets for the first five tests have already been prepared.

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

See also: Cabri at IRSN

CIP members' area (password protected | reminder)


Czech Republic, Finland, France, Germany, Japan, Korea, Slovak Republic, Spain, Sweden, Switzerland, United Kingdom and United States

Project period

January 2016-March 2018


Initial cost of EUR 74 million