Status of the neutronic analyses for the electron cyclotron-heating upper launcher of ITER

The ITER tokamak is a thermonuclear D-T fusion reactor of 500 MW fusion power of which 400 MW is released by neutrons which leads to a total neutron flux of some 1014 cm-2 s-1 at the first wall (FW) surrounding the plasma chamber. The paper reports the latest results in the neutronic modelling and analyses of the electron cyclotron resonance heating upper launcher (ECHUL) installed in the ITER upper port. The neutronic calculations have been performed for the ITER reference front steering launcher design. The aim of the paper is to present results for nuclear responses such as neutron flux, heating and helium production which are important with regard to the nuclear criteria specified for ITER. The Monte Carlo N-particle (MCNP) code was used for the radiation transport calculation with a 3D geometry model of the launcher integrated into the ITER MCNP model. For the conversion from the CAD to MCNP geometry of the launcher the automated interface program McCad was used. In this work the methodology of the performed calculations is first introduced in section 2, followed by a summary of the ECHUL concept and recent changes to the launchers geometry in section 3. The analysis regarding the nuclear responses is presented in section 4. A conclusion of the results is given in section 5. (orig.)