The Instant Harbour

Press, Volume CIX, Issue 31923, 26 February 1969, Page 16

The Instant Harbour

The proposal to make a deep-water harbour at Cape Keraudren, Western Australia, by using nuclear explosives is attractive as an engineering expedient, but its benefits are open to question. The Atomic Energy Commission, which under Project “ Plough- “ share ” is studying the feasibility of the plan, has said, not very comfortingly, that there would be no vast contamination of Australian beaches. Some contamination clearly cannot be avoided; and the question becomes one of degree.

Radioactive fall-out could be completely avoided by making the nuclear excavation inland. The area would be decontaminated before the wall separating it from the sea was breached by some conventional means. But the trouble and cost of decontamination would be so heavy as virtually to rule out this method. The method most likely to be favoured is the underwater explosion of “ clean ” bombs — hydrogen devices which do not produce such dangerous contaminants as strontium 90. There would still be some fall-out because each “clean” bomb—five or six might be used —would have to be detonated by a bomb of the conventional atomic type similar to, and about the size of, those dropped on Hiroshima and Nagasaki. Residue radiation from such bombs would be insignificant Those who suffered from radiation in the two Japanese cities are believed to have been exposed to the radiation at the time of the explosion and not from the contamination of their environment.

But the “clean” bomb would produce another contaminant, tritium, a radioactive substance which would become a constituent of water and thus enter the life-cycle of plants, fish, animals, and humans. Tritium is one of the least harmful of the radioactive substances; but its full effects on life are not yet known. Some scientists regard the use of “ dirty ” atomic devices for excavations as preferable to the unpredictable consequences of tritium. Scientific opinion is still divided on whether tritium will become diluted sufficiently quickly for its effect on life to be negligible. Enough is known about tritium, however, for consideration to have been given to the problems it will present as a by-product of the proliferating nuclear power stations, which must be considered in relation to the general question of the constant pollution, by nuclear as well as other means, of the earth’s surface. Tritium will retain half its radioactivity after 12 years, and a quarter after 24 years. What will happen in those 12 or 24 years? Will other hydrogen blasts have raised the level of radioactivity on the earth significantly? No-one knows. The disquietude that must be felt about the use of hydrogen bombs in this part of the world cannot be allayed by physicists, engineers, and chemists alone; ecologists and biochemists should form part of the team studying this project The advantages and disadvantages of using nuclear explosives to build a harbour must be assessed in terms ‘of life as well as of technology.