Creep Comparison Between Type 316 Stainless Steel and Nimonic PE-16 Used as the First Wall in a Fusion Reactor

Damage caused by neutrons in the first wall of fusion reactor is studied in detail for two different structural materials (Type 316 stainless steel and Nimonic PE-16) in the Princeton fusion power plant design. The first-wall neutron spectrum is calculated by the ANISN code, and a dosimetric analysis is performed for both materials. Moreover, a complete study of damage (swelling and creep) during reactor life is done for Type 316 stainless steel. On the basis of a 1% creep strain, the lifetime of a Type 316 stainless steel first wall is calculated to be ∼2 yr, compared with the ∼22-yr lifetime obtained for Nimonic in the Princeton design. In this way, the economic advantage of a superalloy, compared to stainless steel, has been confirmed.