ARIES-ST safety design and analysis

Activation and safety analyses were performed for the ARIES-ST design. The ARIES-ST power plant includes a water-cooled copper centerpost. The first wall and shield are made of low activation ferritic steel and cooled with helium. The blanket is also made of ferritic steel with SiC inserts and Li17Pb83 breeder. The divertor plate is made of low activation ferritic steel and uses a tungsten brush as plasma facing component. The power plant has a lifetime of 40 full power years (FPY). However, the centerpost, first wall, inboard shield and blanket were assumed to be replaced every 2.86 FPY. Neutron transmutation of copper resulted in the production of several nickel, cobalt and zinc isotopes. The production of these isotopes resulted in an increase of the time-space average electrical resistivity of the centerpost by about 6% after 2.86 FPY. All of the plant components met the limits for disposal as Class C low-level waste. The off-site doses produced at the onset of an accident are caused by the mobilization of the radioactive inventory present in the plant. Analysis of a loss of coolant accident (LOCA) indicated that the centerpost would reach a maximum temperature of about 1000 8C during the accident. In the meantime, the first wall and shield would reach a maximum temperature of about 800 8C. A similar divertor LOCA analysis indicated that the front tungsten layer would also reach a maximum temperature of about 800 8C. The calculated temperature profiles and available oxidation-driven volatility experimental data were used to calculate the dose at the site boundary under conservative release conditions. The current design produces an effective whole body early dose of 1.88 mSv at the site boundary. In addition, a divertor disruption would only produce an effective whole body early dose of 7.68 mSv at the site boundary. # 2002 Elsevier Science B.V. All rights reserved.