"It's not so much for the veterans, but the children and grandchildren of the veterans, because of the health issues that the majority of veterans have and recorded medical problems with their children."
Mr O'Donnell was a stoker on the Canterbury and said major health issues were reported by 350 of the ships' companies who had been in contact with the group.
Six weeks ago, the Hastings businessman, 61, had a tumour removed from his back. It was twice the size of a cancerous tumour taken out in a previous operation.
"I'm keeping myself positive working for the vets to get something that's going to look after the welfare of my children," he said.
Veterans Affairs Minister Michael Woodhouse has said the Government would be open to considering a study if it had evidence, and the group is trying to gather information on health problems in three generations.
About 550 New Zealand Navy men witnessed nine British nuclear blasts during Operation Grapple at Christmas Island and in the Malden Islands in Kiribati in 1957 and 1958.
Mr Woodhouse said that despite no study establishing health problems resulting from Mururoa, a presumptive list of disabilities existed for veterans of Operation Grapple and Mururoa.
If a veteran was diagnosed with a presumptive condition, that could not be ruled out as being attributable to their service.
Veterans were entitled to free medical treatment in relation to each disability on the list.
The Veterans Affairs Ministry said 84 Mururoa veterans were receiving the War Disablement Pension as at June 30, up from 79 the year before.
