The canisters were pushed into place through the front of the reactor-- known as the charge face-- and once the neutrons had worked their magic and turned a good portion of the metallic uranium into plutonium, they were pushed out through the back into a water duct for cooling. The reactor itself was cooled by way of a fan-driven air duct which forced air over the reactor core and out the 400-foot-tall discharge stacks. As a last-minute modification, and at a great effort and expense, a filtering system was added to the top of each chimney at the insistence of a physicist named Sir John Cockcroft. These filters came to be known as "Cockcroft's Folly" due to their engineering difficulty and questionable value.
It was not understood during the plant's construction that graphite which is subjected to neutron bombardment has a tendency to store that energy within dislocations in its crystalline structure. This stored energy is called Wigner energy, named after physicist Eugene Wigner who discovered the effect during his own experiments. Left unchecked, graphite has a tendency to spontaneously release its accumulated Wigner energy in a powerful burst of heat. This was made apparent after two years of operation, at which time unexpected temperature increases were observed in the cores. On one occasion this occurred while the reactor was shut down.
To combat the Wigner energy buildup, the operators at Windscale instituted a process whereby the accumulated energy was allowed to escape by heating the graphite bricks to 250+ degrees Celsius, a process called annealing. At such temperatures the crystalline structure of the graphite expands enough to allow the displaced molecules to slip back into place and release their stored energy gradually, causing a uniform release which then spreads throughout the core. These annealing cycles were executed every few months, and they were performed while the reactor was fully loaded with its 35,000 cannisters of metallic uranium.
For a time, annealing succeeded in preventing the excessive buildup of Wigner energy. But the reactors and their attendant instrumentation were not designed with annealing in mind, therefore the monitoring equipment tended to provide misleading feedback to the reactor operators. The cycles were also notoriously unpredictable, releasing the pent-up energy at temperatures which varied from one instance to the next. In 1957, Windscale operators modified their procedures to require annealment every 40,000 Megawatt-days rather than every 30,000. They were growing concerned with the observation that higher temperatures were required each time, and that unexpected pockets of excessive Wigner energy were lingering in the graphite piles between cycles.
On 7 October of that year, the operators of Windscale Atomic Pile Number 1 began what would turn out to be its final annealing cycle. After the initial heating of the reactor core, the control rods were re-inserted to slow down the fission process and allow the reactor to cool. The temperature monitors, however, indicated a premature dwindling of temperature in the core, leading the operators to believe that the annealing had not been successfully initiated. Unbeknowsnt to the workers, the readings produced by their equipment were inaccurate due to a combination of improperly placed instruments and uneven heat distribution caused by higher-than-normal pockets of Wigner energy.
Based on this misleading information, the operators made a fateful decision-- they restarted the annealing process by heating the reactor once more. When the control rods were withdrawn to allow the fission reactions to increase, the temperature inside the graphite stack increased to dangerous levels. The heat became so extreme within the core that one of the canisters containing uranium or magnesium/lithium isotopes ruptured, spilling its contents and causing oxidation. The blocks of graphite-- a substance which cannot burn in the air except under extreme conditions-- began to smolder.
Early in the fourth day of the annealing process, operators felt that something was amiss when some instruments indicated the core temperature was not slowly falling as expected, but actually increasing. Their fears quickly compounded as they realized that the needles were pegged on the radiation meters at the top of the discharge stacks. The shift foreman declared an emergency. When the operators attempted to examine the pile with a remote scanner, much to their frustration the mechanism jammed. The reactor manager's deputy Tom Hughes and another operator then made their way to the charge face of the reactor wearing protective gear to make a visual inspection of the core. A fuel channel inspection plug was opened, and as Hughes later recounted, "We saw to our complete horror, four channels of fuel glowing bright cherry red."
The reactor had been burning for nearly forty-eight hours. Plant manager Tom Tuohy climbed eighty feet to the top of the reactor building clad in full protective equipment and breathing apparatus, and examined the rear discharge face while standing on the reactor lid. He saw a red luminescence lighting up the space between the back of the reactor and the rear containment wall.
Unsure of how to deal with a fire of this nature, operators tried turning the cooling fans to full power in order to bleed off heat, but the oxygen provided by this effort only fueled the fire. Tuohy suggested removing fuel cartridges from the heart of the fire manually by forcing them from their channels and into the cooling ponds using scaffolding poles. The effort was valiant, but the poles were unable to withstand the punishment. They were red hot as as they were withdrawn from the nuclear furnace, and the ends were dripping with molten radioactive uranium. As one of the men battling the unique fire described the exposed fuel channels, "It was white hot, it was just white hot. Nobody, I mean, nobody, can believe how hot it could possibly be."
Next the men borrowed twenty-five metric tons of liquid carbon dioxide from the newly-built gas-cooled Calder Hall reactors next door. Equipment was rigged to deliver the carbon dioxide to the charge face, but the heat from the fire was so intense that the oxygen was liberated from the carbon atoms upon contact, feeding the blaze into a renewed intensity.
By the morning of Friday 11 October, eleven tons of uranium were burning. Equipment was registering temperatures of 1,300 degrees Celsius in the reactor, and climbing at a rate of 20 degrees per minute. The cement containment around the burning reactor was in severe danger of collapse due to the extreme heat. Having no other viable options, the operators decided to attempt to extinguish the fire with water. This was a very risky proposition, as molten metal oxidizes when in contact with water. The oxidation would create copious amounts of free hydrogen in the highly heated environment, possibly creating an explosion upon mixing with incoming air.
The workers used scaffolding poles to direct their hoses into fuel channels about a meter above the heart of the fire. As the cooling and ventilating air were shut off, Tuohy ordered the evacuation of everyone except himself and the fire chief. Tuohy scaled the reactor shielding one final time and ordered the water turned on. As the hoses sprayed the charge face, he listened carefully for any signs of a hydrogen reaction as the hoses sprayed the graphite core. Several more times he scaled up and down the reactor and reported how the flames slowly died away, "I went up to check several times until I was satisfied that the fire was out. I did stand to one side, sort of hopefully, but if you're staring straight at the core of a shut down reactor you're going to get quite a bit of radiation."
After twenty-four hours, the fire inside the reactor was finally extinguished. Astonishingly, only about 20,000 curies of radioactive material were released into the environment. It was determined that the amount of harmful radiation would have been far greater were it not for the "Cockcroft's Folly" filters. While no citizens were evacuated from the surrounding areas due to the accident, there was some worry about milk from nearby dairy farms becoming contaminated with Iodine-131, which the human body will collect in the thyroid and which can result in thyroid cancer. As a safety precaution, for about a month all milk from the surrounding 500 square kilometers was diluted and dumped into the sea.
Though some radiation was leaked over the countryside, it didn't lead to any immediate death or injury to any of the reactor staff or members of the surrounding community. Reactor Manager Tom Tuohy-- thought to have been exposed to
the most radiation during the event-- is now in his mid-80s and is living with his wife in the USA. One study conducted in 1987 estimated that as many as thirty-three people may eventually die from cancers as a result of this accident, though the Medical Research Council Committee concluded that "it is in the highest degree unlikely that any harm has been done to the health of anybody, whether a worker in the Windscale plant or a member of the general public." In contrast, Chernobyl caused forty-seven immediate deaths and as many as 9,000 may die from related cancer.
Today, some areas of Cumbria still prompt a few clicks from Geiger counters due to lingering caesium-137 isotopes. While the Windscale reactors have been in the process of being decommissioned since the 1980s, the core of Windscale Pile 1 still contains roughly fifteen tons of warm and highly radioactive uranium, and the cleanup is not expected to finish until 2060.
Ultimately the unnecessary incident could have been avoided with a bit of knowledge from the Manhattan project. Had the American government opted to share the nuclear knowledge which the British had helped to gain, the mishap could have been avoided altogether. Fortunately the foresight of Sir John Cockcroft and the valor of men like Tom Tuohy and Tom Hughes prevented this minor disaster from flaring into a national catastrophe.
Originally published 07 May 2007
http://dam.mn/the-windscale-disaster/
Project Babylon: Gerald Bull's Downfall (1958 AD)
Gerald Bull is a prime example of a man who created his own luck--unfortunately for him most of it was bad. A brilliant and distinguished artillery engineer, Bull spent much of his life in the upper echelons of government-funded weapons research. Though his career took him down a convoluted and often difficult path, he devoted his professional life to a single-minded pursuit of his dream: to build a gun large enough to shoot satellites into orbit.
Bull nearly single-handedly resurrected the science of supergun artillery, and in so doing played a major role in 2 wars. But Bull's confrontational style and brusque manner won him very few friends within the governments for which he worked. His poor networking skills combined with a near total disregard for the dangerous politics in which he meddled led to heavy fines, a short stint in prison, and ultimately, to his assassination.
Gerald Bull was born in Ontario, Canada in 1928 and earned his PhD from the University of Toronto in 1951--the youngest ever to do so. He spent his early career working for the Canadian and US governments doing research in supersonic flight as well as supergun artillery.
His first job was working for the Canadian Armament and Research Development Establishment (CARDE) research facility where he suggested that large artillery be used to test models at supersonic speeds. He argued that because supersonic wind tunnels were expensive to build and operate, a large gun would accomplish the task much more efficiently. His project was funded, built, and operated until its cancellation in 1956. Despite later being promoted to head of the aerospace department in 1958, he was forced to leave CARDE in 1960 because of a variety of both public and private conflicts with his superiors.
Bull moved next to McGill University where he quickly interested the US government in his ideas. With money from both the Pentagon and the Canadian government, Bull established the High Altitude Research Project (HARP). Over the next seven years, HARP built a succession of larger and larger guns with ever-increasing capabilities. By the time the Canadian government pulled out of HARP in 1967 in protest of the Vietnam War, Bull had managed to launch shells more than 60 miles into sub-orbital space.
Embittered by what he viewed as premature cancellations of two very promising projects, Bull went into business for himself. He managed to transfer the HARP gun to his private company, the Space Research Corporation (SRC), on the Quebec/Vermont border before leaving the government project entirely. Bull and the SRC limped along on a variety of small US and Canadian arms contracts until, in the mid-1970s, their first big contract came along.
With the help of the CIA, Bull landed a contract to supply the South African government with 30,000 artillery shells, artillery barrels, and plans for an advanced Howitzer called the GC-45. His help was considered by some to be vital in South Africa's ultimate victory over Angola in that war. But, after President Carter came to office in 1976 Bull was arrested by the UN in South Africa for illegal arms dealing and, as per the terms of his plea, served six months in a US penitentiary in 1980.
After his release, Bull continued to improve his Howitzer designs for the South African company Armscor. The end product was the G5 Howitzer that is capable of firing rounds over 30 miles. It was then--and remains today--one of the most advanced pieces of artillery in the world. But at home in Quebec, he was again sued and fined $55,000 for international arms dealing. After the suit he emigrated from Canada and set up shop in Brussels with a subsidiary of the SRC.
His success on the G5 won the attention of both Iraq and China. He built and sold advanced artillery to both nations through an Austrian outfit throughout the 1980s. Having developed something of a personal rapport with Iraqi dictator Saddam Hussein, Bull finally saw an opportunity to realize his ultimate goal. He convinced Hussein that, like Israel, Iraq needed the ability to launch satellites into orbit if it were ever to become a true regional power.
Work began on Project Babylon with a prototype of the supergun in the mid-1980s. This gun, named Baby Babylon, had a bore diameter of about 1 foot, and was approximately 100 feet long. It was mounted horizontally for test purposes, and was believed to have been constructed solely to develop the technology needed for Big Babylon. Nevertheless, Baby Babylon would have had a range of over 400 miles if properly mounted.
The appropriately named Big Babylon was so large that it had to be dug into a hillside for support. Its bore was 3 feet in diameter, and was over 500 feet long. Once completed it would have been capable of launching over 2 tons into orbit--about the size of a small reconnaissance satellite.
Bull was not entirely blind to the implications of Project Babylon, and according to some sources, he briefed several intelligence agencies including Britain's MI5 and Israel's Mossad on the ultimate aims of the project. Because it was completely immobile, slow to fire, and highly visible, Bull argued that Big Babylon was not a direct military threat to Israel or anyone else.
In 1990, the political winds shifted again; Iraq invaded Kuwait. Bull now found himself in the very difficult position of working for a dictator who was suddenly an enemy in the eyes of the entire world. Even worse, Bull had been working for years to improve Iraq's Scud missile in exchange for Hussein's funding of Project Babylon.
In early 1990, Bull's apartment in Brussels was broken into several times over the course of a few months. Each time, items would be purposefully rearranged or carefully ransacked. In retrospect, these break-ins were probably a warning to Bull that went unheeded. In March 1990, Bull was shot five times in the back of the neck while entering his apartment. No one heard the shots, and no one saw the shooter.
There are a number of theories as to who killed Bull. Israel's Mossad is the prime suspect, but there are rumors that the CIA wanted to prevent Bull from talking about its activities in South Africa during the war. Iraq and Iran are both suspects as well; Bull may have been suspected by Hussein of being an agent of the Western governments, and Bull's help in the Iraq-Iran war of the 1980s had meant the deaths of thousands of Iranian troops.
Gerald Bull's story is a fascinating one full of intrigue and tragedy. Like very few others, his fate was tied to events on the world stage. Yet his ill luck owed much to his personality and insensitive pursuit of his dream. After the fall of Iraq in Operation Desert Storm, Project Babylon was dismantled entirely and shipped back to the UK where most of its parts had originated. Brilliant and cagey, Bull carried most of his expertise to the grave. Because of this loss of knowledge, along with his ultimate failure and spectacular downfall, supergun artillery may have forever perished with him.
Originally published 26 May 2006
http://dam.mn/project-babylon-gerald-bulls-downfall/
Rider on the Storm (1959 AD)
In the summer of 1959, a pair of F-8 Crusader combat jets were on a routine flight to Beaufort, North Carolina with no particular designs on making history. The late afternoon sunlight glinted from the silver and orange fuselages as the US Marine Corps pilots flew high above the Carolina coast at near the speed of sound. The lead jet was piloted by 39-year-old Lt Col William Rankin, a veteran of both World War 2 and the Korean War. In another Crusader followed his wingman, Lt Herbert Nolan. The pilots were cruising at 47,000 feet to stay above a large, surly-looking column of cumulonimbus cloud which was amassing about a half mile below them, threatening to moisten the officers upon their arrival at the air field.
Mere minutes before they were scheduled to begin their descent towards Beaufort, William Rankin heard a decreasingly reassuring series of grinding sounds coming from his aircraft's engine. The airframe shuddered, and most of the indicator needles on his array of cockpit instruments flopped into their fluorescent orange “something is horribly wrong” regions. The engine had stopped cold. As the unpowered aircraft dipped earthward, Lt Col Rankin switched on his Crusader's emergency generator to electrify his radio. “Power failure,” Rankin transmitted matter-of-factly to Nolan. “May have to eject.”
Unable to restart his engine, and struggling to keep his craft from entering a near-supersonic nose dive, Rankin grasped the two emergency eject handles. He was mindful of his extreme altitude, and of the serious discomfort that would accompany the sudden decompression of an ejection; but although he lacked a pressure suit, he knew that his oxygen mask should keep him breathing in the rarefied atmosphere nine miles up. He was also wary of the ominous gray soup of a storm that lurked below; but having previously experienced a bail out amidst enemy fire in Korea, a bit of inclement weather didn't seem all that off-putting. At approximately 6:00 pm, Lt Col Rankin concluded that his aircraft was unrecoverable and pulled hard on his eject handles. An explosive charge propelled him from the cockpit into the atmosphere with sufficient force to rip his left glove from his hand, scattering his canopy, pilot seat, and other plane-related debris into the sky. Bill Rankin had spent a fair amount of time skydiving in his career—both premeditated and otherwise—but this particular dive would be unlike any that he or any living person had experienced before.
Unsettling May Have Occurred: Occasionally Uncomfortable Obscure True Stories from Human History Page 16