Misplaced Pages

#213786

65-518: Vemork is a hydroelectric power plant outside the town of Rjukan in Tinn Municipality in Telemark county, Norway . The plant was built by Norsk Hydro and opened in 1911, its main purpose being to fix nitrogen for the production of fertilizer. At opening, it was the world's largest power plant with a capacity of 108 megawatts (145,000  hp ). Vemork was later the site of

130-745: A greenhouse gas . According to the World Commission on Dams report, where the reservoir is large compared to the generating capacity (less than 100 watts per square metre of surface area) and no clearing of the forests in the area was undertaken prior to impoundment of the reservoir, greenhouse gas emissions from the reservoir may be higher than those of a conventional oil-fired thermal generation plant. In boreal reservoirs of Canada and Northern Europe, however, greenhouse gas emissions are typically only 2% to 8% of any kind of conventional fossil-fuel thermal generation. A new class of underwater logging operation that targets drowned forests can mitigate

195-463: A low-head hydro power plant with hydrostatic head of few meters to few tens of meters can be classified either as an SHP or an LHP. The other distinction between SHP and LHP is the degree of the water flow regulation: a typical SHP primarily uses the natural water discharge with very little regulation in comparison to an LHP. Therefore, the term SHP is frequently used as a synonym for the run-of-the-river power plant . The largest power producers in

260-449: A BBC documentary series and book called The Real Heroes of Telemark giving a more realistic view of the difficulties encountered in the mission to sabotage the heavy-water power plant. In 2015, Håkon Anton Fagerås made a statue in bronze of Joachim Rønneberg on commission. It was unveiled by Princess Astrid in Ålesund. In May 2016, a book by Neal Bascomb , The Winter Fortress: The Epic Mission to Sabotage Hitler's Atomic Bomb ,

325-469: A different habitat in a different part of the country. The programme was a rating success, regularly featuring in the top 30 watched programmes of the week. 2013 also saw Mears write My Outdoor Life , which was a Sunday Times bestseller. In 2014, he presented Wilderness Walks , where he visited six areas of natural beauty across the United Kingdom. Each episode would see Mears spend day in

390-421: A flood and fail. Changes in the amount of river flow will correlate with the amount of energy produced by a dam. Lower river flows will reduce the amount of live storage in a reservoir therefore reducing the amount of water that can be used for hydroelectricity. The result of diminished river flow can be power shortages in areas that depend heavily on hydroelectric power. The risk of flow shortage may increase as

455-494: A hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel -powered energy plants. However, when constructed in lowland rainforest areas, where part of the forest is inundated, substantial amounts of greenhouse gases may be emitted. Construction of a hydroelectric complex can have significant environmental impact, principally in loss of arable land and population displacement. They also disrupt

520-809: A large natural height difference between two waterways, such as a waterfall or mountain lake. A tunnel is constructed to take water from the high reservoir to the generating hall built in a cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway. A simple formula for approximating electric power production at a hydroelectric station is: P = − η   ( m ˙ g   Δ h ) = − η   ( ( ρ V ˙ )   g   Δ h ) {\displaystyle P=-\eta \ ({\dot {m}}g\ \Delta h)=-\eta \ ((\rho {\dot {V}})\ g\ \Delta h)} where Efficiency

585-451: A larger amount of methane than those in temperate areas. Like other non-fossil fuel sources, hydropower also has no emissions of sulfur dioxide, nitrogen oxides, or other particulates. Reservoirs created by hydroelectric schemes often provide facilities for water sports , and become tourist attractions themselves. In some countries, aquaculture in reservoirs is common. Multi-use dams installed for irrigation support agriculture with

650-465: A location exploring the local wildlife and offering advice on how to find wild food and make the most of natural resources. In 2015 he presented Wild River , a one-off episode where he explores the wildlife around the River Wye. 2016 saw him present Wild Australia where he explored the wildlife of several locations both on land and in the sea, coming across several iconic Australian species, such as

715-462: A non-fiction account of the operation by one of its operatives, Knut Haukelid, Skis Against the Atom , was published by Willian Kimber, later revised by Fontana Books in 1973, and then by North American Heritage Press in 1989. In 1965, director Anthony Mann made a rather less accurate film version of the story entitled The Heroes of Telemark , starring Kirk Douglas and Richard Harris . In 1975,

SECTION 10

#1732797155214

780-514: A non-fiction book by Thomas Gallagher called Assault in Norway was published by Harcourt Brace Jovanovich . The book's cover states that the book is "the true story of the secret mission that blasted Hitler's dream of an atomic bomb." Swedish metal band Sabaton put the song "Saboteurs" on the Coat Of Arms album in 2010 which tells the story In 2003, British survival expert Ray Mears made

845-592: A positive risk adjusted return, unless appropriate risk management measures are put in place. While many hydroelectric projects supply public electricity networks, some are created to serve specific industrial enterprises. Dedicated hydroelectric projects are often built to provide the substantial amounts of electricity needed for aluminium electrolytic plants, for example. The Grand Coulee Dam switched to support Alcoa aluminium in Bellingham, Washington , United States for American World War II airplanes before it

910-548: A relatively constant water supply. Large hydro dams can control floods, which would otherwise affect people living downstream of the project. Managing dams which are also used for other purposes, such as irrigation , is complicated. In 2021 the IEA called for "robust sustainability standards for all hydropower development with streamlined rules and regulations". Large reservoirs associated with traditional hydroelectric power stations result in submersion of extensive areas upstream of

975-540: A result of climate change . One study from the Colorado River in the United States suggest that modest climate changes, such as an increase in temperature in 2 degree Celsius resulting in a 10% decline in precipitation, might reduce river run-off by up to 40%. Brazil in particular is vulnerable due to its heavy reliance on hydroelectricity, as increasing temperatures, lower water flow and alterations in

1040-753: A seven part series, where he visited a range of habitats and looked at several iconic animals, including Snow Leopards and Giants Pandas . Mears met his first wife, Rachel, in 1992 when she attended one of his five-day survival courses. The couple lived in Eastbourne , East Sussex with her two adult children and married in 2005, after Rachel was diagnosed with breast cancer . Rachel died in 2006, aged 50, and her ashes are scattered in Ashdown Forest near their home. Mears married again in 2009 to Ruth. They live in Sussex with her stepson. In 2019 he

1105-448: A small TV/radio). Even smaller turbines of 200–300 W may power a few homes in a developing country with a drop of only 1 m (3 ft). A Pico-hydro setup is typically run-of-the-river , meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before returning it to the stream. An underground power station is generally used at large facilities and makes use of

1170-455: A source of low-cost renewable energy. Alternatively, small hydro projects may be built in isolated areas that would be uneconomic to serve from a grid, or in areas where there is no national electrical distribution network. Since small hydro projects usually have minimal reservoirs and civil construction work, they are seen as having a relatively low environmental impact compared to large hydro. This decreased environmental impact depends strongly on

1235-414: A start-up time of the order of a few minutes. Although battery power is quicker its capacity is tiny compared to hydro. It takes less than 10 minutes to bring most hydro units from cold start-up to full load; this is quicker than nuclear and almost all fossil fuel power. Power generation can also be decreased quickly when there is a surplus power generation. Hence the limited capacity of hydropower units

1300-581: A total of 1,500 terawatt-hours (TWh) of electrical energy in one full cycle" which was "about 170 times more energy than the global fleet of pumped storage hydropower plants". Battery storage capacity is not expected to overtake pumped storage during the 2020s. When used as peak power to meet demand, hydroelectricity has a higher value than baseload power and a much higher value compared to intermittent energy sources such as wind and solar. Hydroelectric stations have long economic lives, with some plants still in service after 50–100 years. Operating labor cost

1365-498: A year's worth of rain fell within 24 hours (see 1975 Banqiao Dam failure ). The resulting flood resulted in the deaths of 26,000 people, and another 145,000 from epidemics. Millions were left homeless. The creation of a dam in a geologically inappropriate location may cause disasters such as 1963 disaster at Vajont Dam in Italy, where almost 2,000 people died. Ray Mears (author) Raymond Paul Mears (born 7 February 1964)

SECTION 20

#1732797155214

1430-452: Is hydroelectric power on a scale serving a small community or industrial plant. The definition of a small hydro project varies but a generating capacity of up to 10 megawatts (MW) is generally accepted as the upper limit. This may be stretched to 25 MW and 30 MW in Canada and the United States. Small hydro stations may be connected to conventional electrical distribution networks as

1495-736: Is a British woodsman, instructor, businessman, author and TV presenter . His TV appearances cover bushcraft and survival techniques . He is best known for the TV series Ray Mears' Bushcraft , Ray Mears' World of Survival , Extreme Survival , Survival with Ray Mears , Wild Britain with Ray Mears and Ray Mears Goes Walkabout . Mears grew up on the North Downs , in Southern England. He attended Downside Preparatory School in Purley and then Reigate Grammar School , where he

1560-635: Is also usually low, as plants are automated and have few personnel on site during normal operation. Where a dam serves multiple purposes, a hydroelectric station may be added with relatively low construction cost, providing a useful revenue stream to offset the costs of dam operation. It has been calculated that the sale of electricity from the Three Gorges Dam will cover the construction costs after 5 to 8 years of full generation. However, some data shows that in most countries large hydropower dams will be too costly and take too long to build to deliver

1625-470: Is highest in the winter when solar energy is at a minimum. Pico hydro is hydroelectric power generation of under 5 kW . It is useful in small, remote communities that require only a small amount of electricity. For example, the 1.1 kW Intermediate Technology Development Group Pico Hydro Project in Kenya supplies 57 homes with very small electric loads (e.g., a couple of lights and a phone charger, or

1690-445: Is initially produced during construction of the project, and some methane is given off annually by reservoirs, hydro has one of the lowest lifecycle greenhouse gas emissions for electricity generation. The low greenhouse gas impact of hydroelectricity is found especially in temperate climates . Greater greenhouse gas emission impacts are found in the tropical regions because the reservoirs of power stations in tropical regions produce

1755-471: Is more than all other renewable sources combined and also more than nuclear power . Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once

1820-462: Is not an energy source, and appears as a negative number in listings. Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that only the water coming from upstream is available for generation at that moment, and any oversupply must pass unused. A constant supply of water from a lake or existing reservoir upstream is a significant advantage in choosing sites for run-of-the-river. A tidal power station makes use of

1885-452: Is not generally used to produce base power except for vacating the flood pool or meeting downstream needs. Instead, it can serve as backup for non-hydro generators. The major advantage of conventional hydroelectric dams with reservoirs is their ability to store water at low cost for dispatch later as high value clean electricity. In 2021, the IEA estimated that the "reservoirs of all existing conventional hydropower plants combined can store

1950-410: Is often higher (that is, closer to 1) with larger and more modern turbines. Annual electric energy production depends on the available water supply. In some installations, the water flow rate can vary by a factor of 10:1 over the course of a year. Hydropower is a flexible source of electricity since stations can be ramped up and down very quickly to adapt to changing energy demands. Hydro turbines have

2015-679: The Bonneville Dam in 1937 and being recognized by the Flood Control Act of 1936 as the premier federal flood control agency. Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as "white coal". Hoover Dam 's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; it was eclipsed by the 6,809 MW Grand Coulee Dam in 1942. The Itaipu Dam opened in 1984 in South America as

Vemork - Misplaced Pages Continue

2080-806: The International Exhibition of Hydropower and Tourism , with over one million visitors 1925. By 1920, when 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land and water. As the power stations became larger, their associated dams developed additional purposes, including flood control , irrigation and navigation . Federal funding became necessary for large-scale development, and federally owned corporations, such as

2145-633: The Tennessee Valley Authority (1933) and the Bonneville Power Administration (1937) were created. Additionally, the Bureau of Reclamation which had begun a series of western US irrigation projects in the early 20th century, was now constructing large hydroelectric projects such as the 1928 Hoover Dam . The United States Army Corps of Engineers was also involved in hydroelectric development, completing

2210-583: The Vulcan Street Plant , began operating September 30, 1882, in Appleton, Wisconsin , with an output of about 12.5 kilowatts. By 1886 there were 45 hydroelectric power stations in the United States and Canada; and by 1889 there were 200 in the United States alone. At the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas. Grenoble , France held

2275-506: The potential energy of dammed water driving a water turbine and generator . The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head . A large pipe (the " penstock ") delivers water from the reservoir to the turbine. This method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand,

2340-773: The BBC with the result that he was not offered the opportunity to present wildlife programmes. Mears was a guest on BBC Radio 4 's Desert Island Discs in January 2014. In 2009, he was awarded the prestigious Mungo Park Medal . In July 2010, Mears was asked by Northumbria Police to help them track fugitive killer Raoul Moat , after he fled his temporary tent-based shelter in the village of Rothbury . Between 2010 and 2013 he presented three series of Wild Britain on ITV. The first series consisted of six 45 minute episodes, while series two and three had ten episodes of programmes lasting half an hour. Each programme would see Mears visit

2405-463: The IEA released a main-case forecast of 141 GW generated by hydropower over 2022–2027, which is slightly lower than deployment achieved from 2017–2022. Because environmental permitting and construction times are long, they estimate hydropower potential will remain limited, with only an additional 40 GW deemed possible in the accelerated case. In 2021 the IEA said that major modernisation refurbishments are required. Most hydroelectric power comes from

2470-462: The Red Kangaroo and Platypus. He then presented six episodes of Wild France , travelling around the country and looking at its wildlife. Following the same format as his previous series, each programme focused on a different environment. He returned to Australia in 2017, presenting the seven part-series Australian Wilderness with Ray Mears. In 2021, he presented Wild China with Ray Mears ,

2535-464: The ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation. Siltation can fill a reservoir and reduce its capacity to control floods along with causing additional horizontal pressure on the upstream portion of the dam. Eventually, some reservoirs can become full of sediment and useless or over-top during

2600-595: The balance between stream flow and power production. Micro hydro means hydroelectric power installations that typically produce up to 100 kW of power. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks. There are many of these installations around the world, particularly in developing nations as they can provide an economical source of energy without purchase of fuel. Micro hydro systems complement photovoltaic solar energy systems because in many areas water flow, and thus available hydro power,

2665-445: The crew who was badly hurt. In 2009, Mears was approached by ITV to present a planned revival of the nature documentary series Survival . The resulting three-part series was rebranded Survival with Ray Mears and broadcast on ITV1 in 2010. Each episode followed Mears as he used his tracking skills to locate bears, wolves and leopards. In a Radio Times interview to promote the series, Mears complained of being typecast by

Vemork - Misplaced Pages Continue

2730-404: The daily rise and fall of ocean water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, can also be dispatchable to generate power during high demand periods. Less common types of hydro schemes use water's kinetic energy or undammed sources such as undershot water wheels . Tidal power is viable in a relatively small number of locations around

2795-505: The dams, sometimes destroying biologically rich and productive lowland and riverine valley forests, marshland and grasslands. Damming interrupts the flow of rivers and can harm local ecosystems, and building large dams and reservoirs often involves displacing people and wildlife. The loss of land is often exacerbated by habitat fragmentation of surrounding areas caused by the reservoir. Hydroelectric projects can be disruptive to surrounding aquatic ecosystems both upstream and downstream of

2860-705: The effect of forest decay. Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned. In 2000, the World Commission on Dams estimated that dams had physically displaced 40–80 million people worldwide. Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, natural disasters or sabotage can be catastrophic to downriver settlements and infrastructure. During Typhoon Nina in 1975 Banqiao Dam in Southern China failed when more than

2925-399: The excess generation capacity is used to pump water into the higher reservoir, thus providing demand side response . When the demand becomes greater, water is released back into the lower reservoir through a turbine. In 2021 pumped-storage schemes provided almost 85% of the world's 190 GW of grid energy storage and improve the daily capacity factor of the generation system. Pumped storage

2990-553: The first plant in the world to mass-produce heavy water developing from the hydrogen production then used for the Haber process . During World War II , Vemork was the target of Norwegian heavy water sabotage operations. The heavy water plant was closed in 1971, and in 1988 the power station became the Norwegian Industrial Workers Museum . A new power plant was opened in 1971 and is located inside

3055-501: The largest amount for the region since 1990. Meanwhile, globally, hydropower generation increased by 70 TWh (up 2%) in 2022 and remains the largest renewable energy source, surpassing all other technologies combined. Hydropower has been used since ancient times to grind flour and perform other tasks. In the late 18th century hydraulic power provided the energy source needed for the start of the Industrial Revolution . In

3120-750: The largest, producing 14 GW , but was surpassed in 2008 by the Three Gorges Dam in China at 22.5 GW . Hydroelectricity would eventually supply some countries, including Norway , Democratic Republic of the Congo , Paraguay and Brazil , with over 85% of their electricity. In 2021 the International Energy Agency (IEA) said that more efforts are needed to help limit climate change . Some countries have highly developed their hydropower potential and have very little room for growth: Switzerland produces 88% of its potential and Mexico 80%. In 2022,

3185-616: The late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand arising from the Industrial Revolution would drive development as well. In 1878, the world's first hydroelectric power scheme was developed at Cragside in Northumberland , England, by William Armstrong . It was used to power a single arc lamp in his art gallery. The old Schoelkopf Power Station No. 1 , US, near Niagara Falls , began to produce electricity in 1881. The first Edison hydroelectric power station,

3250-488: The mid-1700s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique , which described vertical- and horizontal-axis hydraulic machines, and in 1771 Richard Arkwright 's combination of water power , the water frame , and continuous production played a significant part in the development of the factory system, with modern employment practices. In the 1840s, hydraulic power networks were developed to generate and transmit hydro power to end users. By

3315-471: The mountain behind the old power plant. In 1906, the then newly founded Norsk hydro-elektrisk Kvælstofaktieselskab started construction of what was to be the world's largest hydroelectric power plant. The 108-megawatt (145,000 hp) Vemork power station at the Rjukan Falls was the world's largest power plant when it opened in 1911, after four years of construction. The project was so expensive that

SECTION 50

#1732797155214

3380-651: The natural ecology of the river involved, affecting habitats and ecosystems, and siltation and erosion patterns. While dams can ameliorate the risks of flooding, dam failure can be catastrophic. In 2021, global installed hydropower electrical capacity reached almost 1,400 GW, the highest among all renewable energy technologies. Hydroelectricity plays a leading role in countries like Brazil, Norway and China. but there are geographical limits and environmental issues. Tidal power can be used in coastal regions. China added 24 GW in 2022, accounting for nearly three-quarters of global hydropower capacity additions. Europe added 2 GW,

3445-633: The plant site. Generation of hydroelectric power changes the downstream river environment. Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks. The turbines also will kill large portions of the fauna passing through, for instance 70% of the eel passing a turbine will perish immediately. Since turbine gates are often opened intermittently, rapid or even daily fluctuations in river flow are observed. Drought and seasonal changes in rainfall can severely limit hydropower. Water may also be lost by evaporation. When water flows it has

3510-670: The production of heavy water by means of electrolysis. The company built a unit for producing high concentrations of heavy water at the Vemork plant at Rjukan , although for what purpose was not stated. Production started in December 1934. In 1940, the French Government purchased the entire stock, then available, of heavy water from Norway. The Germans had also offered to purchase it, but the Norwegian Government

3575-450: The rainfall regime, could reduce total energy production by 7% annually by the end of the century. Lower positive impacts are found in the tropical regions. In lowland rainforest areas, where inundation of a part of the forest is necessary, it has been noted that the reservoirs of power plants produce substantial amounts of methane . This is due to plant material in flooded areas decaying in an anaerobic environment and forming methane,

3640-586: The trademarking of the name "Ray Mears". Mears first appeared on television in 1994 presenting the BBC series Tracks and then, in 1997, Ray Mears' World of Survival . In 2003, he presented the BBC documentary Ray Mears' Real Heroes of Telemark about the Norwegian heavy water sabotage mission during World War II . In 2003, Mears won The Ness Award . While filming a documentary in Wyoming , US in 2005, Mears

3705-472: The works had to be financed by overseas sources. The plant became the corporate precursor to Norsk Hydro. Ten 6- megawatt (8,000  hp ) T/G sets were supplied by Voith and AEG (units 1–5) and Escher Wyss and Oerlikon (units 6–10). In 1911, construction was complete. The plant itself, was built to power a factory producing artificial fertilizer by a new method invented by Kristian Birkeland . Later, Norsk Hydro developed and realized another project:

3770-524: The world are hydroelectric power stations, with some hydroelectric facilities capable of generating more than double the installed capacities of the current largest nuclear power stations . Although no official definition exists for the capacity range of large hydroelectric power stations, facilities from over a few hundred megawatts are generally considered large hydroelectric facilities. Currently, only seven facilities over 10 GW ( 10,000 MW ) are in operation worldwide, see table below. Small hydro

3835-539: The world. The classification of hydropower plants starts with two top-level categories: The classification of a plant as an SHP or LHP is primarily based on its nameplate capacity , the threshold varies by the country, but in any case a plant with the capacity of 50 MW or more is considered an LHP. As an example, for China, SHP power is below 25 MW, for India - below 15 MW, most of Europe - below 10 MW. The SHP and LHP categories are further subdivided into many subcategories that are not mutually exclusive. For example,

3900-655: Was a member of the Royal Navy section of the Combined Cadet Force . Mears's ambition was to join the Royal Marines , but he could not meet the eyesight requirements for entry. After taking A-levels , Mears briefly worked in an office in the City of London . In 1983, Mears founded Woodlore, a company that offers bushcraft-related courses and paraphernalia. It became so successful that it soon led to

3965-586: Was allowed to provide irrigation and power to citizens (in addition to aluminium power) after the war. In Suriname , the Brokopondo Reservoir was constructed to provide electricity for the Alcoa aluminium industry. New Zealand 's Manapouri Power Station was constructed to supply electricity to the aluminium smelter at Tiwai Point . Since hydroelectric dams do not use fuel, power generation does not produce carbon dioxide . While carbon dioxide

SECTION 60

#1732797155214

4030-403: Was involved in a serious accident. The helicopter in which he and his camera crew were travelling hit the ground during a steep low level turn, and broke apart, rolling to a stop. The fuel tank was ruptured in the accident and escaping fuel covered Mears and the crew. No fire occurred, and Mears was able to escape the wreckage uninjured and assist in the rescue and administer first aid to one of

4095-550: Was later discovered that the Germans were not as close to making an atomic bomb as had been initially feared. Today, the original power plant is an industrial museum. Its exhibitions cover both the heavy-water sabotage operations and the early Norwegian labor movement. A Norwegian movie about the sabotage operation against the heavy water power plant was made in 1948, starring several of the original saboteurs, titled Operation Swallow: The Battle for Heavy Water (USA). In 1954,

4160-470: Was published by Houghton Mifflin Harcourt . Bascomb also wrote a young adult book, Sabotage: The Mission to Destroy Hitler's Atomic Bomb , published May 2016 by Arthur A. Levine Books. Hydroelectricity Hydroelectricity , or hydroelectric power , is electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity , almost 4,210 TWh in 2023, which

4225-545: Was told of its possible military use and gave it to a French agent, who smuggled it to France via England. That supply eventually went back to England. (see Tube Alloys#Paris Group ) During the German occupation of Norway in World War II , the production of heavy water was judged to be a serious enough threat that at least five separate attacks were launched in order to prevent the Germans from making an atomic bomb . It

#213786