Although FinFET devices present attractive properties to control the radiation-induced soft errors, an accurate evaluation is important to ensure more reliable circuits, mainly at the near-threshold regime. This paper provides an evaluation of the SET sensitivity trends for a circuit-level benchmark, exploring different supply voltages using FinFET technology. Also, the adoption of decoupling cells, as a radiation-hardening technique, is evaluated to reduce the soft error susceptibility. Results show that near-threshold operation increases the fault rate in at least 53.2%. In this benchmark, the use of decoupling cells as a hardening technique is more efficient at 0.6V and 0.7V, reaching up to 10.4% on fault rate reduction.