Calculation of the gamma and neutron dose field inside JSI TRIGA Mark II reactor hallJazbec, Anže (Avtor) Snoj, Luka (Mentor) MCNPADVANTGdose rate fieldLOWETRIGAThis thesis describes the development of a stochastic method to calculate gamma and neutron dose rates for the JSI TRIGA reactor, which can be applied to normal and emergency operations. Knowing the dose rates during normal operation is essential to keep workers safe and in the design of appropriate shielding for new experiments while knowing the dose rates during a postulated accident scenario is necessary for developing an emergency response plan. A completely new MCNP model was designed containing the reactor core and the surrounding components within the concrete shield. Furthermore, the reactor platform, reactor hall, reactor basement and the control room were included in order to calculate the gamma and neutron dose fields within the radiation controlled area. Neutrons and prompt gamma rays were validated in the case where a beam tube was left open, and the reactor was at low power. In this way, neutron and gamma dose rate measurements could be taken around the beam port. The delayed gamma source was validated in the case where one of the irradiated fuel elements was placed in a transport cask, and the surrounding dose rates measured. The good agreement between the calculated and measured results meant the model could be used to predict dose rates during normal operation with newly designed shielding for the beam tube no. 5. Before the shield was constructed, its performance was evaluated by the methodology developed in this thesis. Furthermore, an accident scenario involving the loss of water (LOWE) in the reactor pool and the spent fuel pool were analysed using the same methodology. The LOWE scenario is one of several design-based accidents scenarios to be considered when operating the JSI TRIGA reactor, that was analysed for the first time by the same method. The LOWE for the reactor pool was previously analysed using deterministic methods. Provided results will be used for the next revision of the Safety Analysis Report of the JSI TRIGA Mark II research reactor.20202020-12-13 08:15:02Doktorsko delo/naloga122501VisID: 116707COBISS_ID: 49249795sl