GENERATION Is nuclear power history? The awesome power of water... by Chris Meyer, technical journalist This is the 13th in a series of articles being published in Energize tracing the history of nuclear power throughout the world, and some key renewable alternatives. “It was the worst maritime disaster in U.S. repaired. Instead of “removing and replacing as part of the Los Angeles Aqueduct. Three history, more costly than even the April 14, the bulge in the boiler”, the ship’s captain minutes before midnight on March 12, 1928, 1912 sinking of the Titanic, when 1 517 people merely ordered “a patch of metal put over the dam catastrophically failed, and the were lost… It is scarcely remembered today.” the bulge”. This repair could be done “in one resulting flood killed more than 600 people.” National Geographic News (Ref. 3;1) day”, while proper repairs, which would have (Ref. 4; 1) taken “three to four days”, would have meant “It” was the sinking of the steamboat Sultana Until 1995, the failure of the St. Francis dam that other steamboats would have taken the almost 121 years to the day before the was thought to have been “the worst civil POWs home: and made a huge amount of Chernobyl disaster. Like Chernobyl, a massive engineering failure of the 20th century”. money (Ref. 3;2). steam explosion was the culprit. But, unlike However, we now know otherwise. The largest Chernobyl, the steam explosion that killed The result of all this was that, at 02h00 on the civil engineering disaster was unimaginably more than 1700 people shortly after 02h00 on morning of 27 April, more than 1700 ( some greater, and occurred not in the USA, or 27 April 1865 has long been forgotten. sources say, at least 1700) passengers died: the USSR, but in China, in 1975 (see next either from being burned to death in the huge section). Even today, twenty-one years after Chernobyl, fire after the explosion, or drowning in the icy accounts of the Sultana disaster are worth The dam, sited 64 km northeast of the waters of the Mississipi River (Ref. 1 and 2). reading, as they provide a graphic reminder American city of Los Angeles, California, of the awesome power of water: here, water The official cause of the disaster was later was built between 1924 and 1926 under in the form of steam. found not only to be failure to repair the boiler, the supervision of William Mulholland, chief but also “mismanagement of water levels in engineer and general manager of the Los The dismal and horrific tales of how “some the boiler, excerbated by careening”. This is Angeles Department of Water and Power 1700 people”, most of them former prisoners interesting from a technical point of view, and (LADWP). of war returning home after the end of the therefore merits an explanation. American civil war, died are not appropriate In the case of the St. Francis Dam, the cause here. Neither really is the cause of the steam Severely overloaded and top-heavy, the of the disaster was human error, largely from explosion, when “three of the steamship’s four Sultana “listed severely to one side and then a failure to understand that the type of rock boilers exploded”, although it is interesting the other” as the ship followed the “twists and around and beneath the dam was actually unsuitable for supporting it: even though it technically and is mentioned below. turns of the river”. As the ships’ four boilers were interconnected and connected side- appeared solid enough. Another finding was But the main cause of the disaster - corruption to-side, “water would tend to run out of the that only one man, Mulholland, had been and incompetence – is relevant. In other highest boiler” when the ship tipped sideways, responsible for designing and constructing words, the human factor. And, as we shall the dam. creating hot spots on the empty boiler. see in the following, most of the disasters and As the jury recommended, “the construction near-disasters relating to water and dams When the ship tipped the other way, “water and operation of a great dam should never can be traced to the human factor, not the rushing back into the empty boiler would hit be left to the sole judgment of one man, no technology itself. The worst dam disasters in the hot spots and flash instantly to steam, matter how eminent”. One error Mulholland the 20th century, both in the USA and China, creating a sudden surge in pressure” (Ref. made was “failure to compensate for the can both be traced to the human factor. 2;2). additional height added to the dam’s And, as we shall also see, the human factor Therefore, had the captain added water to design”, when he twice added 3 m to and hydropower also played a strange the boilers, the water levels in the Sultana the dam’s original height, to increase the role in influencing the events leading up to might have been high enough to eliminate Chernobyl. water capacity. Perhaps more serious was hot spots forming: and the steamer just might, his interpretation of water leaking from the In the case of the Sultana disaster, the against all odds, have made it. dam, even on the day before the disaster, human factor was greed, and government as normal for a dam of that size. But, as we now know, at 02h00 on the morning incompetence. Some 2300 Union prisoners of 27 April 1865, like at Chernobyl more than of war were allowed onto the steamer, leaving But Mulholland was not alone in misjudging a century later, a sudden and massive surge it dangerously overcrowded, so that the what he saw. Two of the world’s leading in steam pressure made history. operators could make a huge profit (at $5 geologists of the time also “ found no fault with the San Francisquito rock” on which the a head in government payouts), in ferrying The failure of the St Francis dam, and the dam was built: even though we know the dam the men home. Taum Sauk reservoir collapse was built “squarely over the San Francisquito Greed further came into the picture when “The St Francis Dam was a concrete gravity- earthquake fault”: a very dangerous practice a leak in one of the boilers was not properly arch dam, designed to create a reservoir in an earthquake-prone area. energize - December 2007 - Page 34 GENERATION At the beginning of August 1975, a very unusual set of weather conditions in China gave rise to exceptionally severe flooding, statistically described as a “1 in 2000 year flood”. Historically, China has been plagued since time immemorial by severe floods of its rivers that have taken hundreds of thousands of lives, but the circumstances of early August 1975 were exceptionally bad. Firstly, the warm, moist air of Typhoon Nina (that is, Pacific Hurricane Nina) moved in from the South China coast, passed through Fujian province on the coast, and then continued north to Henan province. Typhoons often enter China, causing devastation and flooding when they move inland, but then Typhoon Nina collided with a cold front, something weather forecasts has failed to predict. Aerial oblique view of the St Francis Dam failure. The landslide that caused the dam to fail is clearly visible on the right. Photo: Spence Aerial Photo Collection, UCLA. By kind courtesy of The result was “a set of storms that dropped Prof. David Rogers, University of Missuori-Rolla, USA. a metre of water in three days”. That, on its own would have been a tragedy, and And, what neither the geologists nor million gallons racing down the 530 m high the cause of yet more floods, devastation Mulholland could know was that rock the mountain. and heavy loss of life from China’s rivers, but dam had been built on was actually a Despite all the advances in design since for one fact. The massive floods fell on two huge, ancient landslide, technically a 1928, technical issues and the human factor large dams, the Banqiao and Shimantan “paleomegalandslide”. In fact, so little was were still the cause of the failure in 2005. Dams, built in the early fifties and later that known about this type of rock that dynamite same decade “reinforced and expanded was being used to blast a new road on the Because of “improperly maintained and using Soviet expertise”, and thought to be eastern side of the dam, “much of it right next installed water monitors” (Ref. 6;1), the indestructable (Ref.12;29). Before Typhoon to the unstable abutment” (Ref. 5; 3). The last automatic pumps that filled the reservoir at Nina arrived, officials ignorant of the technical inspection carried out the same day the dam night failed to turn off, “causing water to flow consequences had recently added a “1,9 m collapsed revealed that “the roadbed had over the concrete walls… erode the earthen high earthen embankment” to the Shimantan sagged five feet” (Ref. 4; 3). dam on the other side, eventually causing the wall to fail and the entire reservoir to collapse dam, and also increased the Banqiao dam’s To sum up, the disaster was human error, under cascading pressure” (Ref. 8;1). capacity by 32-million m3 more than its caused by a lack of understanding of the designed safe capacity (Ref.12;32,37). technical issues involved. As Prof. JD Rogers Normally, ever since it was completed in has pointed out in his far more detailed and 1963, water pumped up during the night And not only did the floods fall on these two technical analysis of the disaster (see Ref would be released during the day down a 2 large dams, but on sixty other smaller dams, 5a), the “ancient bedrock landslide which 300 m shaft and tunnel, to spin turbines and many that had been constructed against composed the dam’s entire left abutment” generate electricity (Ref.