New insights to containment management in TRR during severe accident by spray and fan cooler measures

The corium behavior and its effects on containment behaviors along with mitigation measures are investigated for Tehran Research Reactor (TRR) by using the MELCOR and CONTAIN codes during a Severe Accident (SA). According to obtained results, the SAs analysis for the research reactor shows different behavior compared with power reactors. This behavior can be can be investigated in two phases; the initial phase: before the concrete ablation initiation up to 119 days and secondary phase: initiation concrete ablation from 119 to 125 days. During the initial phase, the containment pressure increases at a rate of 0.016 Pa/s and reaches 0.1138 MPa (the maximum pressure of the containment) during about 24 h. In this phase, the effects of the corium initial temperature, corium mass and relative humidity on the containment behavior are not significant. During the secondary phase, the average containment pressure increasing rate is about 12 times more than initial phase. Results show that containment management systems are need to maintain containment integrity. The suggested systems are to use a fan cooler (minimum power capacity 3 kW, coolant flow rate and temperature 0.05 Lit/s and 298 K) or spray (maximum spray droplet temperature 298 K with minimum spray flow 0.001 Lit/s) to mitigate SA.