ITER FUELING, PUMPING, WALL CONDITIONING SYSTEMS AND FUEL DYNAMICS ANALYSIS

In this paper, the status of the ITER fuelling, pumping and wall condi tioning systems design and the results of fuel dynamics analysis will be presented. The fuelling system consists of both gas and pellet inje ction. The max. DT gas fuelling rate is 500 Pa m(3) s(-1) during a pla sma density rise and 200 Pa m(3) s(-1) during steady state DT burn. Th e maximum pellet fuelling rate is 100 Pa m(3) s(-1) (DT) and 50 Pa m(3 ) s(-1) (T-2) during DT burn. The primary pumping system comprises two major subsystems: the high vacuum pumping system and the torus roughi ng system. The former consists of 16 batch regenerating cryopumps loca ted inside the divertor ports with 12 in operation and four in regener ation mode. The net pumping speed of 12 pumps is similar to 200 m(3) s (-1). The latter consists of two sets of mechanical pumps, each contai ning an inlet Roots blower backed by two Roots blower/mechanical pisto n pumps. For wall conditioning, baking and glow discharge cleaning for zero-magnetic field, and electron cyclotron resonance discharge clean ing for high-magnetic field are being examined. Development of a fuel dynamics simulation code including the complete fuel cycle (fuelling, vacuum pumping and tritium plant systems) is in progress for an optimi sation of the fuel cycle. (C) 1998 Elsevier Science S.A. All rights re served.