The panel members conducted its second phase of inspection yesterday and checked if the pollution monitoring equipment at the unit was working properly.
Later they gave the green signal for the operation of the plant and the oxygen plant of the unit was started around six PM. Full-fledged working of the plant is expected to commence in a few days, maximum one week, when production would start, officials said.
Officials said the team inspected the plant ahead of production by the unit and it is expected to stay during the unit's running to see if there is any impact on the environment.
The TNPCB had on May 29 ordered closure of the plant on complaints that it was emitting toxic sulphur dioxide. The NGT then set aside the TNPCB order and allowed Sterlite Industries Ltd to resume operation of its copper smelting unit.
The TNPCB then moved the Supreme Court seeking quashing of the green panel's order but the apex court refused to stay the NGT order allowing Sterlite Industries Ltd to resume operation of its smelting plant in Tamil Nadu's Tuticorin district under an expert committee's supervision.