A gas stripper system for purification of a primary coolant contaminated in cooling a nuclear reactor, the gas stripper system comprising: a gas stripper column adapted to receive the liquid phased contaminated primary coolant, the gas stripper column defining top, bottom and middle sections, the gas stripper column having, a distributor member disposed inside the top of the gas stripper column and adapted to evenly distribute the liquid phased contaminated primary coolant flowing from the top to bottom of the column, a re-boiler member adapted to heat the primary coolant to a gaseous phase, the gaseous phased coolant raises counter current to the liquid phased contaminated primary coolant from the bottom to the top of the column, and a separation member disposed inside the middle section of the column having a structured packing so as to enable maximum contact of the liquid phased primary coolant with the gaseous phased primary coolant raising counter current to liquid phased contaminated primary coolant to be dissolved to obtain vapour phased; and a condenser arrangement provided in communication with the interior of the gas stripper column to receive and condense the vapour phased primary coolant so as to enable non-condensable gases to be discharged and return of the condensate to the gas stripper column, characterized in that the distributor member is adapted to receive the primary coolant from the nuclear reactor, a return line is provided between the bottom of the column and the distributor member, wherein a pump, a heat exchanger, a cooler and a three way valve are provided in the return line wherein the three-way valve is adapted for the primary coolant free from impurities to make exit from the return line via the three-way valve, and the re-boiler member is disposed inside the bottom of the gas stripper column, whereas the separation member is disposed between the distributor and the re-boiler member. a gas stripper column adapted to receive the liquid phased contaminated primary coolant, the gas stripper column defining top, bottom and middle sections, the gas stripper column having, a distributor member disposed inside the top of the gas stripper column and adapted to evenly distribute the liquid phased contaminated primary coolant flowing from the top to bottom of the column, a re-boiler member adapted to heat the primary coolant to a gaseous phase, the gaseous phased coolant raises counter current to the liquid phased contaminated primary coolant from the bottom to the top of the column, and a separation member disposed inside the middle section of the column having a structured packing so as to enable maximum contact of the liquid phased primary coolant with the gaseous phased primary coolant raising counter current to liquid phased contaminated primary coolant to be dissolved to obtain vapour phased; and a distributor member disposed inside the top of the gas stripper column and adapted to evenly distribute the liquid phased contaminated primary coolant flowing from the top to bottom of the column, a re-boiler member adapted to heat the primary coolant to a gaseous phase, the gaseous phased coolant raises counter current to the liquid phased contaminated primary coolant from the bottom to the top of the column, and a separation member disposed inside the middle section of the column having a structured packing so as to enable maximum contact of the liquid phased primary coolant with the gaseous phased primary coolant raising counter current to liquid phased contaminated primary coolant to be dissolved to obtain vapour phased; and a condenser arrangement provided in communication with the interior of the gas stripper column to receive and condense the vapour phased primary coolant so as to enable non-condensable gases to be discharged and return of the condensate to the gas stripper column,