%0Computer Program %TMastodon %XMASTODON has the capability to model stochastic nonlinear soil-structure interaction (NLSSI) in a dynamic probabilistic risk assessment framework. The NLSSI simulations include structural dynamics, time integration, dynamic porous media flow, nonlinear hysteretic soil constitutive models, geometric nonlinearities (gapping, sliding, and uplift). MASTODON is also the MOOSE based master application for dynamic PRA of external hazards. %AColeman, Justin %AVeeraraghavan, Swetha %ABolisetti, Chandrakanth %Rhttps://doi.org/10.11578/dc.20210416.86 %Uhttps://www.osti.gov/doecode/biblio/55053 %CUnited States %D2017 %GEnglish %2USDOE Office of Nuclear Energy (NE) %1AC07-05ID14517 2017-09-13