GENERATION Is nuclear power history? The dream evaporates... by CM Meyer, technical journalist This is the 15th in a series of articles being published in Energize tracing the history of nuclear power throughout the world. “It was truly a case of life imitating art. has since been explained, much of the anti- those arguing that pressurised water reactors Last month, amid a burst of publicity, nuclear feeling in the USA can be ascribed to (the competing V VER design) were more Columbia Pictures released, in the United something not easily explained; an incredible dangerous, and strengthened the Soviet States its film "The China Syndrome. coincidence that a fictional movie about a commitment to continuing and modernizing The fictional tale deals with the near melt- nuclear accident was released just before a the RBMK [3; 239]. real nuclear accident happened. down of a nuclear reactor. Then last week it The Three Mile Island incident was basically almost happened in real life.”[10; 20] Three Mile Island; what happened? caused by a faulty valve. At about 04h00 on In actual fact, the Three Mile Island accident 28 March 1979, the main feedwater pumps of “In the two decades since Three Mile island, of 28 March 1979 was a real meltdown, the non-nuclear section of the plant stopped the plant has become a rallying symbol resulting in more than half of the reactor’s running, because of either a mechanical or for the anti-nuclear movement. But the core being permanently damaged. But electrical failure. This prevented the steam nuclear power industry, which has not built many people living near the damaged generators from removing heat. First the a single new plant in the United States since turbine, then the reactor automatically reactor in Pennsylvania were preoccupied 1979, says the incident shows that its safety shut down. Immediately, pressure in the with something much worse, an enormous systems worked, even in the most extreme primary system, that is, the nuclear part of cloud of radioactive fallout the size of circumstances” [13; 1]. the plant, started to increase, and a relief Pennsylvania that would soon be permanently valve opened to allow pressure to reach a uninhabitable [14; 3] [15; 1]. On 30 March When compared with Chernobyl, where lower level. So far, there wasn’t a problem, 1979, nearly 200 000 people fled their nearly 20-million curies of radioactive and all equipment functioned as originally homes, some for several weeks [12; 1]. materials and several million curies of inert designed until the relief valve failed to close, radioactive gases were released [3; 45], What happened and why? On 19 March, and signals available to the operator failed the actual radioactivity release by the Three 1979, the film “The China Syndrome” was to show that the valve was still open. The rest Mile Island (TMI) accident was miniscule. released for the movie-going public by is basically history. More and more coolant Approximately 43 000 curies of radioactive Columbia Pictures. The film dealt with a water continued to drain from the reactor, krypton was vented from the reactor more fictional near melt-down in a nuclear reactor. slowly exposing the core and leading to a than a year later in preparation for cleanup The title came from the idea that, “if an meltdown in which about one half of the crews to enter the reactor building [11; 4] American nuclear plant melts down, it will core melted. [12; 1]. This came after a significant release melt through the Earth until it reaches China” of radiation from the plant’s auxiliary building, Because of badly planned instrumentation, [14; 1]. Although intended as a joke, some performed to relieve pressure on the primary a crucial error was missed as no instrument viewers might well have believed this really system and avoid curtailing the flow of showed the level of coolant in the core, and would happen. But then came the actual coolant to the core on 30 March 1979. In the inadequately trained operators failed Three Mile Island accident. Nine days and simpler language, steam from the leaking to realise that the plant was experiencing more after the release of the movie, tens pilot-operated relief valve over-pressurised a a loss-of-cooling accident. The operators of millions of Americans could turn off the tank in the auxiliary building, and a bursting misunderstood what was happening, and evening news, walk down the street to the disc released it automatically into the turned off the emergency core cooling movie theatre and see a film version of what building. system. But, even though the plant suffered they had been watching on television all a severe core meltdown - the most week. [15; 1] And, not surprisingly, many got This release of radiation resulted in an average dangerous kind of nuclear power accident, confused between the conflicting accounts dose to about 2-million people in the area of the containment vessel held and virtually no of what they were seeing in the news with about 1 millirem, less than that for a full set of radioactivity was released. Unlike Chernobyl, the fictional explanations of the film. Small chest x-rays (about 6 millirem). The maximum there was no actual explosion, by steam wonder then that, when the Governor Dick dose to someone at the site boundary would or otherwise. A major concern in a core- Thornborough advised an estimated 3 500 have been less than what one would have meltdown scenario is that the core will melt pregnant women and children living within received from natural background radiation through the pressure vessel and start to attack five miles of the plant to evacuate the area, in the area during a year, about 100 to the concrete container. This did not begin to many more people responded with alacrity. 125 millirem per year [11; 2 – 3]. Ironically, happen. Two results of the accident were that Not surprisingly, the enthusiasm the American there was a link to Chernobyl. Soviet nuclear Generation II reactors (the type then in use) public had for nuclear power dropped energy planners studied the incident, but and practices were modified to make them considerably after the Three Mile Island sincerely believed that the RBMK design was much safer, while Generation III reactors accident. While what actually happened actually safer. The TMI incident actually served (e.g. the EPR and AP 1000, contenders for energize - April 2008 - Page 44 GENERATION Eskom’s nuclear programme) must be able and with it went Harwell’s livelihood. The USA Hinton’s words, written in 1958 during the to accommodate core meltdown. took much the same decision when it shut heyday of nuclear power now have an ironic down the integral fast reactor program in ring to them: “British supplies of coal are While a large hydrogen bubble was found 1994, at a time when the price of oil was little running short. All of our oil is imported. From in the core, the absence of oxygen in the more than $10 per barrel. Like the American the outset we realized that we would need pressure vessel meant that it could not decision, the British decision has proved nuclear power and need it soon.” [6; 35]. explode. Plant operators later managed to to be equally short-sighted. After 1992, greatly reduce the bubble’s size [11; 1-2]. Chernobyl: the hidden conflict the British North Sea oilfield had practically But, unlike the hydrogen bubble, public fear been exhausted. Once again, a means of “If it had not been for the atomic bomb, exploded. While steps were taken to correct using nuclear reactors as a source of electric sustainably using energy was obliterated by the instrumentation and improve training of energy would probably still be in the research the short-term lure of fossil fuels. The ironic operators, all further nuclear plants in the US stage. The technology is far too expensive difference is that this time it was not solar were put on hold. Exhaustive public hearings, for civilian use alone” [3; 226] power or wind power that was affected, but delays, and consequent huge increases in the best and most promising means of using If you mention the word “Chernobyl”, many will costs were now associated with all plans nuclear power economically. automatically associate it with the ill-starred for nuclear power plants, and after the Chernobyl disaster, any positive sentiments for nuclear power seemed to have disappeared forever. In the United Kingdom, Chernobyl came after an even bigger blow to nuclear power; the discovery of oil in the nearby North Sea. Harwell versus North Sea Oil “In that same year (1969) oil and gas deposits were discovered off the Norwegian coast and in 1975 in UK waters. By 1981, the UK had become a net exporter of oil and with energy costs falling to an all time low, the nuclear power dream evaporated.” [2; 116] When Calder Hall, the first British nuclear power station opened on 17 October 1956, [6;29], nuclear power was seen as the solution to the United Kingdom’s energy problems. In 1956, the UK government White Paper planned for twelve nuclear power stations, totalling 2000 MW, to produce electricity at a price cheaper than burning oil [2; 107]. After the Suez crisis of late 1956 this target was revised to 6 000 MW (halved two years later) and the golden age of nuclear power had seemingly arrived [2; 108]. In the 1980s the British government began to cut back on funding for nuclear research. For the first time ever, some researchers at Harwell, the world-renowned atomic energy research establishment that had virtually developed British nuclear power technology from scratch, faced the grim prospect of redundancy.