A leading anti-nuclear figure has cast doubts over the integrity of radiation screening in Port Kembla, saying the tests were grossly inadequate.Dr Helen Caldicott made the comments after tests on a ship full of cars from Japan returned negative readings.Two Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) inspectors boarded the Trans Future 7 yesterday morning to test 102 of the ship's 800 new and used vehicles.The tests were conducted only after Port Kembla dock workers raised concerns they could be exposed to radiation from the earthquake and tsunami-ravaged Fukushima nuclear plant.Dr Caldicott has spent four decades warning of the dangers of nuclear energy and is considered an expert on the subject.The Nobel Peace Prize nominee said the best way to properly detect radiation in vehicles was to remove and test engine and passenger compartment air filters.Inspectors tested the engine filter of only one car yesterday instead relying on hand-held monitors to scan the external and internal surfaces of the 102 vehicles."ARPANSA is trying to cover this up and say 'look, we know what we're doing' but they don't," Dr Caldicott said."If they don't do these [air filter] tests they're scientifically negligent."This is very serious. As a physician and paediatrician I can't tell you how concerning this is to me."ARPANSA acting chief executive officer Professor Peter Johnston told the Mercury filters would have to be destroyed if they were tested."Our exercise [yesterday] was one primarily of reassurance," he said. "Our guidance remains that such inspections and screening aren't strictly necessary."The nuclear safety regulator has decided there is no need to screen any more sea or air cargo arriving from Japan, including that aboard another ship due in Port Kembla today."There are some people out there who are interested in maintaining this issue in the media and that's their right [but] I don't think it should impact on our risk-based assessment of where we should expend our radiation detection resources," Prof Johnston said."We can be accused of many things by many people and if that's their view, that's their view."Maritime Union of Australia assistant national secretary Warren Smith also said he had reservations about the rigour of yesterday's tests.