29th Symposium on Fusion Technology (SOFT 2016)

P2.004 ITER oriented neutronics benchmark experiments on neutron streaming and shutdown dose rate at JET

6 Sep 2016, 14:20

1h 40m

Foyer 2A (2nd floor), 3A (3rd floor) (Prague Congress Centre)

Board: 4

Poster A. Experimental Fusion Devices and Supporting Facilities P2 Poster session

Speaker

Rosaria Villari (EUROfusion Consortium)

Description

Neutronics benchmark experiments are conducted at JET for validating the neutronics codes and tools used in ITER nuclear analyses to predict quantities such as the neutron flux along streaming paths and dose rates at the shutdown due to activated components. In particular, in the frame of subproject NEXP of JET-3 program, several activities are performed within EUROfusion Consortium devoted to the preparation of neutronics experiments for the future Deuterium-Tritium operations (DTE-2 campaign). During plasma operations, neutron fluence and dose measurements will be performed using thermoluminescent dosimeters (TLDs) and activation foils located in several positions inside and outside the Torus Hall. At the shutdown, decay gamma dose rates will be measured using passive and active dosimeters installed inside and outside JET vessel. Decay gamma dose in-vessel measurements will be performed with TLDs and high-sensitive, low activation, spherical ionization chambers will be used to measure the dose rate versus time after irradiation in two ex-vessel positions on the side-port of Octant 1 close to radial neutron camera and in Octant 2 on the top of ITER-like antenna. The results of the measurements will be compared with three-dimensional calculations carried-out with MCNP5 and MCNP6 Monte Carlo Codes as well as with ADVANTG hybrid code. Shutdown dose rate measurements will be used to validate recent versions of three-dimensional MCNP-based Rigorous-Two Steps and Direct-One Step European tools used in ITER analyses. The experimental assembly has been accurately designed so far and careful analyses have been performed for the selection of the detectors as well as the experimental positions and operative conditions. Measurements and analyses are in progress in the current Deuterium-Deuterium (DD) campaign. This work is devoted to present the status-of-art of neutronics experiments including selection and detectors’ assembly, irradiation tests performed in neutron and gamma facilities, calibration, pre-analyses and recent results during DD operations.