IGNORING THE PERILS.

SCIENCE NUCLEAR POWER: GOVERNMENT IS By Our Scientific Correspondent, J. H. Bradley THE recent accident to a turbine at the Calder Hall extensions caused no radio-active dangér, since radioactive materials do not pass near the turbine.

It seems that the device which keeps the speed of the turbine constant must have failed, and it-speeded up so much that it flew apart.

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This could not have happened if it had been supplying power to the National Grid, for it would have had to speed up all the other power stations in the country. Obviously one turbine cannot give enough energy to do this.

Yet the incident shows that our power stations must be safe even in face of extensive damage. In those now being built the reactor is cooled by high-pressure carbon dioxide, a slightly poisonous gas which becomes only very minutely radio-active in the process.

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.The heat from the carbon dioxide is given up to steam in . devices called heat-exchangers, and the steam then drives turbines as in a-normal steam power station.

If one of the heat exchangers were so badly damaged that most of the carbon dioxide escaped in a few minutes, something like the Windscale catastrophe could result, only on a smaller scale.

Fuel’ rods might burst, or. become overheated and melt, and if air got in a serious fire could result.

Serious fire could result .

These things are very unlikely, but it is no use pretending they could not happen. It is almost impossible to say how great is the risk—or,.in scientific terms, how often it will happen—and a great deal can be done to cut down the risks.

But if it happens-once in a century the price will be well ‘worth while, for it means no less than the survival of Britain as an industrial nation whose coal reserves are running out very fast.

The decision to make plutonium for bombs in the new power stations is.far more dangerous, not to mention the cost. In order to make the plutonium-239 needed for bombs, fuel rods have to be replaced much more often than if the plutonium is to be used for future power stations.

The longer the rods stay in, the more of the useless uranium238 is converted to plutonium-239, but also the more plutonium-239 is converted to the. useless plutonium-240. :

A little plutonium-240 can be tolerated in a power station; but it makes the bombs of lower power.

There has been a debate in our cclumns about the real meaning of de Gaulle’s coming to power. We think it important that the debate should continue. Here is a reply by our Paris correspondent, Seymour Papert, to the letter from David Finch (see The Newsletter, June 21, p. 166) criticizing his views, and the first of four articles by John Archer putting forward another Now, apart from the dangers of a sudden pressure loss when changing fuel elements (just as if a heat exchanger were suddenly burst open), moving fuel elements with the reactor running is a ticklish affair. — Without pewer for hours Jf it should cause any of the reactor safety devices to turn off the power station, an intolerable strain would suddenly be thrown on other power stations in the area, and a large part of the country couid be without power for several hours.

Such things have been known before, when a failure in one station or a transmission line overloaded all the other stations. Back in the days of power cuts it used to happen quite often.

Then it can happen that a fuel rod gets jammed, breaks, or caiches fire.

This recently happened at the Canadian reactor NRX at Chalk River, and the whole building had to be cleaned far more carefully than any operating theatre. The reactor will not be working for several months.

A little bit of radio-activity even got outside the building, though not enough to be dangerous more than a hundred yards away. .

More fuel rods means more factories for their processing, and more people exposed to the risks of these factories. More transport of rods means greater risks on the road and railways.

All over the town A new, unused fuel rod is slightly poisonous but not radioactive. Some of them can catch fire in a very hot flame.

Just imagine, though, if a lorryload of used fuel rods met a paint of view. Readers are invited to jcin in the debate.

By 12, 1958 _ JUL petrol tanker, and the resulting fire blew radio-activity all over one of our big towns.

And just try finding a route from Somerset or Essex to north- . east Cumberland without going through a town.

Everybody has seen what a rail smash does to coaches. If a few fuel elements were mixed up in that twisted mess there would be an intolerable risk to rescuers and injured alike.

There is no sign that the necessary radiation monitors, or facilities for treatment, or protective clothing is available.

I know of no evidence that the problem has even been thought of in Whitehall.

All these risks will.come-in any civilian power plan, but the making of military plutonium will make them three or four times as common. ; :

Insurance companies are demurring Happily there seems to be one place where sanity may y=>t prevail. The insurance underwriters do not seem inclined to let nuclear powered ships. go sailing about just anyhow.. ‘ The bill for putting Southampton Docks, the Port of London, or the North Sea fishing grounds out of action for twenty or thirty years may seem nothing to the squanderers of the H-bomb. but the insurance companies do not seem to want to have to pay it.

Perhaps it is unreasonable to expect the question to cross the mind of a government which thinks it more important to be able to drop bombs on Moscow when most of our nation is dead than to: store up wheat, canned food, blood plasma, medical supplies and essential raw materials for those who might have some chance of survival.