Every year in the United States alone, there are more than 1,000 officially acknowledged accidents in nuclear facilities. Of these, between 50 and 100 are in the "serious" category.

Each U.S nuclear power plant is forced to shut down for repairs on average ten times per year as a result of mechanical or human failure.

Nobody knows precisely how many mishaps there have been so far - many go unreported, and the military reactors are immune from public scrutiny - but the following is a list of just some of the many publicised and fully reported near misses:-

1957 Hanford - United States

The waste from the military plutonium production facilities at Hanford is stores in 150 huge tanks, some of which are leaking already. Over half a million gallons are lost. Ironically, though these wastes must be stores for thousands of years, the leaks are blamed on "old Tanks"

1957 Windscale No. I U.S.

The Windscale No. 1 Plutonium reactor was destroyed by an internal fire caused when un unexpected surge of heat ignited fuel and graphite in the air coolant. Only air filters, installed on the coolant discharge stacks in the preceding months as a belated safety precaution, prevented a disastrous spread of radioactivity over the surrounding countryside. Many thousands of gallons of milk contaminated with radioactive iodine 131 had to be poured into the sea, and the plume of radioactivity was detected by instruments in London, a few thousand miles away.

1961 United States

Three operators were killed in a burst of radiation as an experimental reactor in Idaho goes out of control. The reactor core is destroyed, and a full week goes by before shielded clean-up workers can enter the building to recover the bodies.

1966 Enrico Fermi No. I U.S.

A piece of sheet metal - added as an after thought safety device deep inside the core cooling complex tears loose, blocking the flow of coolant. The temperature of the reactor core soars beyond the reach of the mechanisms on hand to control it. There is a partial melt down and for several agonised hours, officials face the prospect of having to order the complete evacuation of Detroit. The first Sodium cooled Fast Breeder Reactor to be built for a new generation of commercial electricity is now in ruin, deserted by all except permanent security guards. It is decided to close down and dismantle this, the Enrico Fermi No. I reactor - the trouble is that over a decade later nobody knows how to

1968 San Onofre U.S.

At the San Onofre nuclear plant in southern California a turbine blade breaks, causing alarmed operators to turn off the reactor too quickly. This activates a back up cooling system which should have been turned off. As a plant spokesman later says: "Someone forgot". This causes a drop in pressure thus causing the emergency core cooling system to turn on; however, there is no place for the emergency cooling water to go. This causes both the plant and its emergency core cooling system to be damaged by the resulting vibrations, and the plant is shut down for months.

1972 Robert Ginna U.S.

Fuel elements discharge from the Robert Ginna reactor in Rochester, New York, and prove to have undergone serious deformation during irradation. The fuel pin cladding is crushed and crumpled, and upon examination is found to be partially empty. Nobody knows how this happened - but similar types of fuel are being used in several factors now in operation in the United States Worries are being expressed that a wholly new phenomenon has been discovered, not necessarily confined to this type of fuel element.

1973 Oak Ridge U.S.

Hijackers sieze a Southern Airways jet and threaten to crash it into the dale Ridge Nuclear power station in Tennessee. U.S. fighter planes stand by to shoot it down and the station (since nothing else can be done) is evacuated.

1973 United States

861 "safety-related" accidents are officially reported in the AEC's annual report on nuclear facilities. Several nuclear utilities are discovered to have failed to report additional accidents.

1973 - McMurdo - New Zealand

In 1962 the U.S. Navy install a nuclear power station at McMurdo Sound, in the Ross Sea dependency of Antarctica (administrated by N.Z.) It gives a lot of technical trouble and is finally shut down in 1973. The official U.S. publications state the reasons for the final shutdown as suspected cracks in a coolant pipe and the pressure vessel. (Incidentally, the reactor did not have an Emergency Core Cooling System.) But the Superintendent of N.Z.'s D.S.I.R. Antarctic Research Station, Mr R.B. Thomson, claims that it was shut down for "purely economic reasons".

1973 Oyster Creek U.S.

An operator's mistake causes 50,000 gallons of radioactive water to be emptied into the basement of the Oyster Creek nuclear plant in New Jersey, causing it to close down.

1973 Vermont Yankee U.S.

The Vermont Yankee plant experiences 17 major shut-downs in its first 19 months of "operation", and it is learned that the devices critically important in controlling the nuclear reaction were installed upside down.

1973 Atucha Argentina

A nuclear power station nearing completion in Argentina is seized by guerillas.

1974 Shevchenko Russia

American observation satellite detects a dosium flare at the Russians' East Breeder reactor at Shevchenko on the Caspian Sea. This is thought to indicate a release of several hundred litres of liquid sodium coolant, which reacted explosively with water, certainly one, and probably two similar accidents have already occured at Shevchenko.

1974 United States

A January, 1974 AEC study reports that 5 U.S. nuclear plants built by General Electric have "broken or bent hanger bolts, no lock nuts, improper bolts" and other deficiencies which "could negate the operability of the ECCS".

1974 U.S

All four fuel reprocessing plants in the USA are shut down The plant at the West Valley, New York, is emitting more than the permissible levels of radioactivity. To date, none of the plants are back in operation.

1975 Browns Ferry U.S.

At the twin-reactor nuclear power station at Browns Ferry an electrician is using a candle to detect air leaks in the pressurised cable ducts under the control room. The candle touches the "flame-retardant" plastic foam in the wall and sets it alight. The resultant cable fire disables, at a single stroke, five supposedly independent emergency core cooling systems, the remote controls for the several vital valves and diesel generators, and burns out of control for several hours. The incident is called a "Comedy of Errors", and exposes numerous equipment and operator failures. It has since been stated that there was one chance in ten trillion years of reactor operation that such an incident could have occured.

1975 U.K.

British nuclear power stations are threatened with bombing by the I.R.A.

West Germany

At the Biblis(a) nuclear power station - the worlds largest - a man suceeds in walking through the security checks and room. He carried with him a bazooka capable of blasting a four inch hold in the pressure valve.

1975 France

The Fessenhein nuclear power plant is blasted by two bombs, causing sufficient damage to the reactor core to put back construction work for three months. Responsibility is claimed by an anti-nuclear "commando" group linked to the Red Army Faction, or Bader-Meinhof Gang.

1975 France

A month later tow charges explode simultaneously in the suburbs of Paris at offices and factories belonging to a French-American nuclear power company. One charge destroys experimental reactor valves at Argenteuil, the other heavily damaged the company's computer at Courbevoie. Resposibility is claimed by another terrorist "commando" group, inspired by the Fessenheim attack.

In Brittany, the Mont Aree nuclear power station is bombed, causing its immediate shut down. The attack is attributed to the Breton Liberation Front, a separatist movement.

March 1976 United States

Nuclear waste storage pits on the shores of Biscayne Bay are reported to be leaking at a rate of more than 90 gallons an hour. Both the company and the NCR have known about the leak for some years, but repair efforts are proving difficult due to radioactivity so intense that it is impossible for men to work in the pits.