First-Order and Second-Order Sensitivity Studies of ARCON96 for Ground Release Mode

ARCON96 is the latest USNRC-recommended relative atmospheric concentration calculation program for design basis control room radiological habitability assessments at nuclear power plants. In order to thoroughly evaluate ARCON96 and to provide guidance for ARCON96 implementation, both first and second order systematical sensitivity studies were performed to ARCON96 for ground level release mode. A deterministic Taylor series approximation approach was utilized to analyze the sensitivity of ARCON96 model to wind speed and the distance from the release point to the intake. The sensitivity of ARCON96 was investigated with all atmospheric stability classes for complete evaluation. The results of this study reveal that the sensitivity of ARCON96 is primarily dominated by first-order sensitivity. And the behavior of sensitivity for wind speed and distance is quite different. The computed variance proves the robustness of ARCON96 model in presence of input parameter perturbation.