According to police, the incident took place in S S Organics factory situated at the outskirts of Aroor village under Sadasivpet police station limits.
However, there were no casualties in the incident.
The mishap took place after smoke began emanating from the sodium filled reactor, prompting the authorities to evacuate the factory before the reactor caught fire.
Firemen are still fighting the flames. The cause of the blaze is still not known and further probe is on.