(eng): The environmental code HARP (HAzardous Radioactivity Propagation) estimates consequences of accidental radioactivity releases from a nuclear facility and on basis of simulation of dispersion in atmosphere, deposition of radionuclides on the ground and further propagation through the food chains towards human body. Classical Gaussian approach in the form of hybrid puff-plume segmented model SGPM is introduced for simulation of pollution dissemination in the atmosphere. The ingestion pathway is modeled dynamically. The system architecture consists of the inner kernel designated for deterministic calculations and outer probabilistic shell, which ensures application of probabilistic approach in the consequence assessment. Propagation of uncertainties through the model towards the output values of interest is realized through the multiple recalling procedure of the inner kernel, which is optimized for such intensive Monte Carlo (MC) computations.