Mumbai: Bhabha Atomic Research Centre (BARC) has designed and developed the first of its kind advanced automation system for transfer of spent fuel bundle of Pressurised Heavy Water Reactors for nuclear reprocessing plants.

"Introduction of this automation system for reprocessing plant is aimed at transferring  the fuel bundles directly from fuel handling area (FHA) of storage pool to the dissolver cell in an automated way, without the necessity  of using charging cask," Director of Remote Handling and Robotics and Design, Manufacturing and Automation Group of BARC Manjit Singh said.

"This contributes in eliminating dependency on skilled man-power and thus reduction of man-rem (radiation dose) consumption by workers," Singh said.

A preliminary safety analysis report (PSAR) has been reviewed and approved by the BARC Safety Council and the first automated system for spent fuel nuclear reprocessing plant will be set at Tarapur in Maharashtra soon and work in that direction has already begun, he said.

Singh also pointed out that the system design is such that it can easily be adopted to handle fuel from 220MW PHWR as well as from 550 MW / 700 MW with minimum changes. Provision has also been kept for manual changing of spent fuel in case of non-availability of automation system, he added.

The spent fuel bundles from nuclear power reactors (in this case PHWRs) are stored under water at reactor site. After allowing it to cool down for given period, spent fuel bundles from reactor site are transferred to underwater storage facility at the nuclear fuel reprocessing plant site, D N Badodkar of the Division of Remote Handling and Robotics, who developed the design, said.

The spent fuel bundles are stored in an array of trays from ease of handling consideration and currently the spent fuels from storage pool are transferred to the reprocessing plant manually which includes –lowering of cask, transfer of fuel bundles (11 bundles weighing about 200 kg) from the storage tray to the charging cask using manually operated single or multiple underwater gripper assembly. The fuel bundles are pushed (total pushing stroke of about 7m) manually in stages one after the other after lifting of cask out of the pool and its alignment to shielded transfer port of the chopper cell.

"This operation requires dependency and availability of trained and skilled manpower. During the handling of fuel bundles from pool to the chopper unit (through charging cask) also results sometimes in spillage of contaminated water all around on the floor and this new automated system could solve many of these problems being faced in the current  system of manual operation,"  Singh added.

(Agencies)