National Aerosol Facility

The pilot scale plant – National Aerosol Facility (https://home.iitk.ac.in/~snt/naf/index.html) built from scratch by Dr. Tripathi in collaboration with Reactor Safety Division (RSD) and Radiological Physics and Advisory Division (RP&AD) of BARC and AERB is an integrated facility with provisions for aerosol generation from plasma torch, aerosol mixing in a reaction chamber, aerosol transport through 550 m of the piping network and vessels for a wide range of parameters relevant to Indian PHWR nuclear plant in dry and wet conditions. The plant is equipped with heaters for maintaining temperatures (0-350 ◦C), compressors for pressure (0.5 – 5 bar) and an industry scale boiler (300 kg per hour) for steam generation. Parameters including temperature, pressure and aerosols and droplets can be measured online using sensors installed at critical locations and controlled remotely by programmable logical controller using SCADA system.

NAF is indeed a first of its kind in an Asian University and it has two phases of study involving four entities of Department of Atomic Energy (DAE). A series of investigations have already been completed related to understanding of nuclear aerosol behaviour (deposition, charging, hygroscopic growth and nucleation) (Kumar, Tripathi et al., 2025; Mishra, Tripathi et al., 2025; Kumar, Tripathi et al., 2022; Mariam, Tripathi et al., 2022; Dwivedi, Tripathi et al., 2020; Mishra, Tripathi et al., 2020; Ghosh, Tripathi et al., 2020; Dwivedi, Tripathi et al, 2019; Mishra, Tripathi et al., 2019; Ghosh, Tripathi et al., 2017). Pilot experiments (scaled down Large Aerosol Experiment) in straight as well as curved test piping sections were already carried out by a combined team of Prof Tripathi’s group and BARC scientists.

Two new projects soon to commence will focus on characterizing aerosols generated during postulated reactor accidents to improve inputs for source term in numerical codes, with emphasis on measuring particle charge, shape, and size distribution and support and examine aerosol retention under severe accident conditions. The data generated from experiments performed is being used by Indian Atomic Energy agencies for safety evaluation of their nuclear plants. In future the plant can be reconfigured to measure aerosol leakage from chemical industries for environmental safety analysis.