Colin,
no not involved. I came across the reference in avia13/1239 at TNA. The ballistics trials at Woomera were to prove/calculate the ballistic properties of the RAF's inventory of air-dropped weapons. So "N" bomb drops would be inert. I don't know whether the "N" bombs ever entered service. I did wonder if interest in the Large Area Coverage concept (spraying the stuff from aircraft/ships) put the kibosh on bombs (which had rather limited cover in comparison). But I've never really gone into the subject in any detail.
rs