GENERATION Is history? From Montebello to ...

by Chris Meyer, technical journalist

This is the ninth of a series of articles being publishers in Energize tracing the history of nuclear energy throughout the world.

“We have to have this thing [the atom bomb] were: and the role played in all this by the given to the scientists working at the top- over here whatever it costs…we have got to man the Americans dubbed the “Smiling secret wartime laboratory in Los Alamos in have [the] bloody Union Jack on top of it” Killer”. 1944, and illustrated his abilities: analytical skill, expertise, effective communication, and, Ernest Bevin, Foreign Secretary, 1946, The “Smiling Killer” and the British bomb especially valuable in producing nuclear launching the development of nuclear “His presentation was in a scientific matter- weapons, translating results into practical weapons in the United Kingdom. (Ref. 6; 1) of-fact style, with his usual brightly smiling applications. On 3 October 1952, roughly one year after face; many of the Americans had not This made him an especially valuable the construction of first nuclear submarine been exposed to such a detailed and member of the team, amply demonstrated had begun in the United States and three realistic discussion of casualties, and he when he worked out a method to measure years after the arrest of Klaus Fuchs, the was nicknamed “the Smiling Killer” (Peierls, the energy of the blast from the first bomb first British atom bomb test took place. This 1985: 201) tested: a “number of wooden boxes was staged in a little-known group of islands The man Rudi Peierls was describing was prepared with circular holes of varying sizes, (Trimoulle Island, one of the MonteBello William G Penney, a British specialist in the covered with paper” (Peierls, 1985: 203). The Islands), just off the west coast of Australia. physics of hydrodynamic waves (which overpressure of the blast wave ruptured the The test took place underwater (2,7 m below included shock waves and ocean waves). paper of the larger holes, while the paper water), largely vaporising the ship holding the The presentation he gave that unnerved covering the smaller holes remained intact. bomb, the HMS Plym, with a few hot metal his American audience was on the effect By examining the size of the largest holes fragments causing fires on the nearby island of German bombing on England, and the still covered, Penney could calculate the ( Ref. 7, 1-6). casualties this caused. Penney’s talk was overpressure, the intensity of the blast wave, The idea of a ship-borne bomb was then a major concern to the British, and had first been raised by no less a person than Albert Einstein in late 1939. In his famous letter to President Roosevelt, which warned of the possibility of nuclear weapons being made and led to the starting of the Manhattan Project, Einstein had noted that a “single bomb of this type, carried by boat and exploded in a port, might very well destroy the whole port together with some of the surrounding territory” (Wheeler K, 1983:20).

At that time in 1939, nobody, even Einstein, had yet realised that a few kg of -235 or could be used to make a bomb light enough for an aircraft to carry. Initial calculations had shown that thousands of kg of natural uranium metal would be needed to make a , and a ship would thus be the only way to transport it.

Although the idea of a ship-borne bomb seems ridiculous in an age of missiles with nuclear warheads, the successful test was a major triumph for the United Kingdom’s nuclear energy programme.

Today, this test is all but forgotten. Also nearly forgotten is the role the nuclear programme played in establishing the peaceful uses of nuclear power in the United Kingdom, and how intertwined these two programmes then Sir Christopher Hinton, architect of the first British atomic power stations. Photo: Courtesy of UKAEA.

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and thus the energy released by the bomb But none of this would have been possible But unlike GLEEP, which is now in the process (Peierls,1985: 203). He also worked with Fuchs without plutonium, and the man assigned to of being decommissioned (Ref.9;1-2), on the implosion problem, central to the coordinate its production, Christopher Hinton. the F-1 is still reportedly being used, to building of the plutonium bomb. He was also And, as we shall see, it was no coincidence calibrate flux detectors. When in involved in planning the height the bombs that Hinton designed the first nuclear power use, between 1947 and 1990, GLEEP had should be dropped on their targets. station in Britain, Calder Hall (Ref. 7;1-6). a typical power output of 3 kW, slightly more than that of an electric kettle. Despite this On 27 April 1945, Penney was the only Briton GLEEP, the first reactor in Europe low power level, this research reactor was on the ten-man Target Committee that drew “GLEEP (Graphite Low Energy Experimental very successful at its key function, namely up the list of potential targets in Japan for the Pile)…was the first built in calibrating instruments and testing the atom bomb. Later he moved to Tinian, one Europe, established in 1947, but its uses were purity of materials being used for larger, of the Malvinas islands, to assist in planning not all peaceful.” The Guardian, 2 June, 2004 more powerful reactors. On its “time off”, and debriefing the bombing missions to (Ref. 10; 1-3) Hiroshima and Kokura. Nagasaki was only on week-ends, GLEEP was used to make radioactive isotopes. bombed because the aiming point in Kokura At the time GLEEP was being built in 1946, was obscured by smoke (Wheeler,K. 1983: another reactor was being built whose uses GLEEP even had a small railway running 99-101). were far from peaceful. In Moscow, the first through the lower part of the reactor’s core. Penney was on an aircraft that witnessed the reactor to go critical in the USSR started The “Danger Coefficient Train” was used bombing of Nagasaki. Later, together with operating on 25 December 1946 (see “The to measure “the purities of uranium fuels, some American specialists, he spent days Road to Chernobyl: Kurchatov, the F-1 and boron, and cadmium control rods” and walking the streets of Hiroshima and Nagasaki, Chelyabinsk-40”). This reactor, called F-1, several “hundreds of tons of graphite” used studying the damage and collecting samples was used to test materials and operating to construct reactors in the UK. procedures used in Cheliabinsk-40, the of the destruction for later study. Building GLEEP, the first reactor in Europe, was industrial-scale production reactor built later no easy job, especially in post-war Britain in On 1 January 1946, he was appointed to produce plutonium for the Soviet nuclear 1947, where many materials (even steel) “Caesar” (CSAR, chief superintendent of programme. Armament Research), a post which he was then in short supply. So important was knew would soon carry the responsibility for Like F-1, GLEEP was also used to test the GLEEP considered that the then British prime developing Britain’s atomic bomb. This he materials and operating procedures for a minister, Clement Atlee, ordered reinforcing did with great distinction, later supervising larger production reactor, (then being built steel bars intended for repairing the Houses the development of Britain’s first hydrogen at Windscale), to produce plutonium. Both of Parliament (damaged by German air raids bomb. GLEEP and the F-1 did not produce electricity. in World War II) to be diverted to GLEEP.

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Another material in very short supply was Calder Hall, the world’s first commercial to ensure that there is sufficient duplication uranium, so “the outer part of the core, power station? and diversity in the cooling systems to ensure weighing 26 tonnes, was made up of that coolant loss is effectively impossible: “It must be realised that Calder Hall was built aluminium cans containing uranium dioxide something Rickover’s designers of pressurised essentially for the production of plutonium, pellets wrapped in paper.” The central core water reactors had learned to do by the time and that electrical power was generated contained twelve tonnes of uranium, made the ‘Nautilus’ was launched in 1955. only as a by-product” (Hinton, 1958:33) up of “one inch [diameter uranium] bars The core of a gas-cooled reactor will also one foot long”. At first, these bars were not Depending on what source you consult, melt if its coolant is lost. However, there is no covered by metal cladding. no fewer than three nuclear power stations risk there in overheating of water suddenly are recorded as being the first to produce However, there were concerns that, if GLEEP expanding ca 2000 times in volume as it turns electricity for commercial use: Obninsk 5 were to be used at its full design power of to steam and causing an explosion. Largely MWe, USSR (27 June 1954), Calder Hall 4 x 50 100 kW on weekends to make radioisotopes, for this reason, Hinton opted for gas-cooled MWe, UK (17 October,1956), and Shippingport then unclad uranium rods might “produce reactors in his designs. 60 MWe (December 1957, USA). But the first highly radioactive fission products that could actual demonstration (in the USA) of nuclear- Soon after GLEEP had become operational contaminate the surrounding air”. generated electricity was in 1951, when four and the first Magnox cladding designed, Klaus Fuchs was asked to check the light bulbs were lit by electricity from the EBR-1 Hinton made a second discovery: “We came calculations (done by a Dr. Littler, see below), (Experimental -1), operated to the conclusion that, by putting cooling fins and he agreed something should be done. by the Argonne National Laboratory (Ref 5; on the fuel-element cans and compressing The solution was to shot-blast the uranium 1-3). our coolant gas, we could design gas- rods, spray them with aluminium paint “to a cooled, graphite-moderated reactors which But how exactly does one define “electricity for thickness of three thousandths of an inch”, would not only produce plutonium but would commercial use”? Does this mean the reactor and then replace them in the core. The at the same time generate electrical power” must be designed primarily to produce aluminium paint was later replaced by proper (Hinton, 1958; 30). electricity, (with perhaps some plutonium aluminium cladding (Ref. 8; 1-6). eventually coming from reprocessing its However, to do this, “the temperature of the When GLEEP was commissioned (on 15 uranium fuel elements) or does it include gas leaving the reactor” had to be “reasonably August 1947), it was some two years since reactors designed primarily to produce high”, and this would involve “more research Christopher Hinton had been assigned the plutonium, with electricity as a by-product? than we had time for”(Hinton, 30). Therefore, job of setting up “an organisation to design the first reactors built at Windscale by 1950 For the first reactors producing electricity in and operate industrial atomic-energy to produce plutonium for the British nuclear the USSR and the UK undoubtedly produced establishments” (Hinton, 1958:29): and programme were air-cooled, and did not plutonium first and electricity second (Ref.10; oversee the production of plutonium. generate electricity. In one incident, the 1-2). It was only once the UK had produced caught fire in October 1957, From GLEEP to Magnox its first hydrogen bomb in May 1957 (and built and involved a major release of radioactivity up an arsenal of 200 atom bombs before “This is where it started. This is like the mother into the atmosphere, “about 20 000 curies 1957 (Ref.7; 1-6) that plutonium production of nuclear power, or nuclear energy, in this of iodine-131, 600 curies of cesium-137, became less of a priority and research country (the UK). And it all started here.” 80 curies of strontium-89, and 2 curies of shifted to building commercial nuclear John Buffery, senior project manager, UKAEA, strontium-90” ) ( Medvedev, ZA,1979;144-145) power plants. commenting on GLEEP (Ref 9; 2) or “some 20 kCi of iodine-131 and 13 kCi of From the very beginning, when Hinton and other radionuclides” (Ref.12; 5) (roughly about GLEEP was an air-cooled reactor, moderated his initial staff of 16 first started on 6 February 0,04% of radioactivity released at Chernobyl). by graphite, and its fuel elements consisted of 1946 to design GLEEP and other nuclear This accident, which happened after Calder uranium metal in sheaths (cladding) of pure reactors that could produce plutonium, his Hall had started operating, underscored the aluminium. Those involved in reactor design thoughts were on using gas as a coolant and correctness of Hinton’s decision to use high- and development very soon discovered the not, as the Americans had done, water. pressure carbon dioxide gas as a coolant for importance of using very pure materials, as the first of the Magnox reactors, Calder Hall very low levels of impurities in the graphite, There were two main reasons for this. Firstly, and subsequent ones (Hinton, 1958; 29-35). uranium or cladding absorbed and thanks to the MacMahon Act and the fallout interfered with the workings of the reactor. from Klaus Fuchs, the United States was in The beginning of the end, or the end of no mood to share the knowledge Rickover the beginning? This led Dr. Derrik Littler, one of the researchers was then building up on pressurised-water working on GLEEP, to make an important “Obviously, when a power plant has a high reactors. discovery. He found that “a special capital cost and a low fuel cost it is most aluminium alloy, containing magnesium But there was another reason. The huge economical to keep it in operation on full and beryllium”could be used as a cladding reactor complex built in Hanford, USA, to load for as many hours as possible during for uranium fuel elements (Ref. 8; 1-6l). When produce plutonium was moderated by the year” (Hinton, 1958; 35) fins were added to this cladding, it was later graphite and cooled by water: and was Today, more than forty years after the first found to be suitable to for use in gas-cooled especially prone to instabilities caused by Magnox reactors were built, a process of reactors. xenon-135 which, at the time, were not very decommissioning these early reactors well understood. Thus it was that the first British reactors used to has already started: Calder Hall among generate electric power came to be called All water-cooled reactors are inherently them. Is this the beginning of the end for Magnox reactors, named after their fuel’s unstable, in that, if the water coolant is lost, nuclear power, or merely the end of the cladding. then the reactor core will melt. The trick is beginning? While encouraging statements

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made recently in the United Kingdom, including some talk of a higher temperatures) will be justified if they lead to the higher temperatures “nuclear renaissance”, now suggest that nuclear power has a which make possible improved thermal efficiencies and more compact definite future, anti-nuclear sentiment remains strong in Europe, units of lower capital cost.”(Hinton, 1958; 35). particularly in Germany. A detailed analysis of this would way In the next article in this series, we shall see how these same four points noted beyond the scope of this article. by Hinton are crucial in arguments used by advocates of the PBMR (Pebble But one can point out four surprising observations made by the Bed Modular Reactor), currently under development in South Africa. architect of Calder Hall and the British programme to generate References plutonium. Hinton, with his remarkably clear thinking, foresaw an economic crisis coming for nuclear power. His argument was an [1] Hinton, Sir Christopher. 1958. “Atomic power in Britain”. Scientific American. economic one (for his prediction of a Chenobyl-type scenario, Vol 198 No 3, 29-35. see the third article in this series), and went as follows. As the use [2] Peierls R, 1985. Bird of passage. Princeton: Princeton University Press. of nuclear power became more widespread, nuclear power [3] Wheeler K, and the editors of Time-Life Books. 1983. The fall of Japan. stations would be forced away from their most economical Chicago: Time-Life Books. mode of operation (running continuously at full load), and [4] Medvedev ZA, 1979. Nuclear disaster in the Urals. London: Angus and become more expensive to operate relative to other options. Robertson. In practice, this never materialised, although cost overruns in [5] “Early reactors in the United States and Russia”.(2006). (http://www. building nuclear plants did make many investors nervous about nucleartourist.com/basics/early.htm) [Accessed May 2006]. building nuclear plants. [6] “History of AWE”.2006. (http://www.awe.co.uk/main_site/about_awe/history/ index.html). Another of his points was more telling: the then declining cost of [7] “Britain’s Nuclear Weapons. From MAUD to Hurricane”. 2002. (http:// coal and other fossil fuels, making nuclear plants less competitive nuclearweaponarchive.org/Uk/UKOrigin.html) [Accessed January 2006]. options than power plants fired by fossil fuels. Obviously, the [8] Personal Communication (2006) from Nick Hance, PRO at Harwell. reverse of his argument also holds true, although it was not considered at the time: if the cost of coal and other fossil fuels [9] Rush J, 2004. “Dismantling the dream”. 20 March 2004. Channel 4 television. (http://channel4.co.uk/news/2004/03/week_3/20_gleep.html) were to increase, then nuclear power would become more [Accessed January 2006]. competitive. Thirdly, Hinton also touched on another key point: [10] Brown P, 2004. “Fission vision”. 2 June 2004. The Guardian newspaper. that nuclear reactors would only be truly economic if they could (http://society.guardian.co.uk/environment/story/0,14124,1229080,00.html) produce a by-product that could be sold. [Accessed January 2006]. Although he had in mind the Magnox reactors, with their [11] Brown M, 2003. “First to close”, 21 March uneconomic fuel cycle designed mainly to produce plutonium, 2003. The Guardian newspaper.(www.guardian.co.uk/nuclear/ article/0,2763,918724,00.html) [Accessed April 2006]. his comments also touch on all uranium-fuelled reactors, namely that “these first-stage reactors can only be economical if a buyer [12] FAO. “Radioactive fallout in soils, crops and food.” (www.fao.org/docrep/ T0228E/T0228E03.htm) [Accessed July 2006]. can be found for their by-product: plutonium”. Here, Hinton envisaged plutonium being used to fuel a fast-neutron reactor [13] 21 December 2005. “Early reactors in the United States and Russia”. which would not need a moderator. At the time, nobody had (www.nucleartourist.com/basics/early.htm) [Accessed July 2006]. v thought seriously of the heat generated by reactors as a valuable, saleable by-product to offset running costs. Heat was considered as a waste product: even though the very first Soviet plant at Obninsk had shown its waste heat could serve a useful; purpose: district heating (Ref.13; 1).

And last, but certainly not least, was the fourth point: the need to operate at higher temperatures. In his words, “in the long run reduction in capital cost of nuclear power plants must arise (as it has in the case of conventional power plants) from the use of higher temperatures in the gas cycle” (Hinton, 1958; 35).

In other words, if the reactor could operate at higher temperatures, it would be more efficient thermally, and thermodynamically.

The problem Hinton notes is that “as we try to take more heat from the fuel elements [here, uranium metal encased in Magnox cladding] we run into difficulties within the uranium itself…we find that the temperature in the centre of the uranium is dangerously high”(Hinton, 1958; 35). To get around this problem, fuel elements “with a smaller cross section” containing , would be needed. These would be more expensive and, to justify costs, would have to be capable of being left in the reactor for longer periods of time to achieve “high burn-ups” (that is, using as much as possible of the enriched uranium fuel. Hinton then notes that using “uranium in a ceramic form” might be an answer, although it would further increase costs. Here, he was probably thinking of ceramic uranium oxide, as later used in AGRs (Advanced Gas Reactors) and LWRs (Light Water Reactors). These were built after the Magnox reactors.

Hinton then goes on to conclude that “all these expenses (involving more expensive fuel elements that can be operated at

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