Workers isolate as COVID outbreak threatens giant Tomago aluminium smelter; CEO Matt Howell vows to keep operations open.

Australia's biggest aluminium smelter is in the midst of a growing COVID cluster and could be forced to scale back production as more staff go into isolation. 

Tomago Aluminium near Newcastle north of Sydney is struggling to keep the smelter open fearing that more workers might be exposed. 

Chief executive Matt Howell tells ABC's Peter Ryan closing the smelter is the last resort.