Tokamak dust in ITER - Safety issues and R&D supporting dust limits

Tokamak dust is an important contributor to the source term in ITER safety analyses. In this paper we present results of R&D at the INEEL and North Ca rolina State University to characterize tokamak dust. These results were us ed to set safety limits on dust for ITER. We present the results of analysi s of particulate collected from three operating tokamaks: DIII-D at General Atomics, TFTR at Princeton Plasma Physics Laboratory, and Alcator C-MOD at Massachusetts Institute of Technology, and analysis of particulate produce d in SIRENS, a disruption simulator at North Carolina State University. Ana lyses done include characterization of particulate to produce particle size distributions, chemical analysis, and measurement of effective surface are a. The safety limits on dust in ITER have evolved during the EDA as more da ta have become available. The safety limits specified in NSSR-2 envelope th e majority of the data, and provide conservatism to account for the uncerta inty in extrapolation of the data to ITER.