Poseidon Nickel Ltd (ASX:POS, OTC:PSDNF) CEO Peter Harold tells Proactive Investors they're continuing to de-risk operations for the restart of its Black Swan nickel project, 50 kilometres northeast of Kalgoorlie in Western Australia. Two underground rigs are currently testing the potential down-plunge extensions and infilling existing inferred resources at the Silver Swan underground mine within the Black Swan project.