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92-464: Monju was a sodium cooled , MOX -fueled, loop-type reactor with three primary coolant loops, designed to produce 280  MWe from 714  MWt . It had a breeding ratio of approximately 1.2. The plant is located on a site that spans 1.08 km (267 acres), the buildings occupy 28,678 m (7 acres), and it has 104,680 m of floor space. An accident in December 1995, in which a sodium leak caused

184-471: A flame test , sodium and its compounds glow yellow because the excited 3s electrons of sodium emit a photon when they fall from 3p to 3s; the wavelength of this photon corresponds to the D line at about 589.3 nm. Spin-orbit interactions involving the electron in the 3p orbital split the D line into two, at 589.0 and 589.6 nm; hyperfine structures involving both orbitals cause many more lines. Twenty isotopes of sodium are known, but only Na

276-423: A phase-transfer catalyst . Sodium content of samples is determined by atomic absorption spectrophotometry or by potentiometry using ion-selective electrodes. Like the other alkali metals, sodium dissolves in ammonia and some amines to give deeply colored solutions; evaporation of these solutions leaves a shiny film of metallic sodium. The solutions contain the coordination complex [Na(NH 3 ) 6 ] , with

368-503: A raising agent , and sodablasting . Along with potassium, many important medicines have sodium added to improve their bioavailability ; though potassium is the better ion in most cases, sodium is chosen for its lower price and atomic weight. Sodium hydride is used as a base for various reactions (such as the aldol reaction ) in organic chemistry. Metallic sodium is used mainly for the production of sodium borohydride , sodium azide , indigo , and triphenylphosphine . A once-common use

460-533: A compound of sodium with the Latin name of sodanum was used as a headache remedy. The name sodium is thought to originate from the Arabic suda , meaning headache, as the headache-alleviating properties of sodium carbonate or soda were well known in early times. Although sodium, sometimes called soda , had long been recognized in compounds, the metal itself was not isolated until 1807 by Sir Humphry Davy through

552-524: A corner of our 60 m room farthest away from the apparatus, we exploded 3 mg of sodium chlorate with milk sugar while observing the nonluminous flame before the slit. After a while, it glowed a bright yellow and showed a strong sodium line that disappeared only after 10 minutes. From the weight of the sodium salt and the volume of air in the room, we easily calculate that one part by weight of air could not contain more than 1/20 millionth weight of sodium. The Earth's crust contains 2.27% sodium, making it

644-427: A defective weld point, allowing several hundred kilograms of sodium to leak out onto the floor below the pipe. Upon contact with air, the liquid sodium reacted with oxygen and moisture in the air, filling the room with caustic fumes and producing temperatures of several hundred degrees Celsius. The heat was so intense that it warped several steel structures in the room. An alarm sounded around 7:30 p.m., switching

736-416: A fast breeder program of some kind, essential if Japan's stockpile of some 50 tonnes of plutonium is to be disposed of. Jōyō is a test fast breeder reactor located in Ōarai, Ibaraki . The reactor was built in the 1970s for the purpose of experimental tests and the development of FBR technologies. The successor to Monju was expected to be a larger demonstration plant to be completed around 2025, built by

828-567: A high affinity for the sodium ion; derivatives of the alkalide Na are obtainable by the addition of cryptands to solutions of sodium in ammonia via disproportionation . Many organosodium compounds have been prepared. Because of the high polarity of the C-Na bonds, they behave like sources of carbanions (salts with organic anions ). Some well-known derivatives include sodium cyclopentadienide (NaC 5 H 5 ) and trityl sodium ((C 6 H 5 ) 3 CNa). Sodium naphthalene , Na [C 10 H 8 •] ,

920-415: A high neutron flux in the reactor. The high boiling point of sodium allows the reactor to operate at ambient (normal) pressure, but drawbacks include its opacity, which hinders visual maintenance, and its strongly reducing properties. Sodium will explode in contact with water, although it will only burn gently in air. Radioactive sodium-24 may be produced by neutron bombardment during operation, posing

1012-403: A kilometer from the reactor site, and would constitute a hazard for the reactor safety. One of the experts, Chiba University professor Takahiro Miyauchi, did not take part in the two-day survey, but would visit the site afterwards. On Thursday 18 July Kunihiko Shimazaki told reporters, that his team could not yet reach a conclusion, further research was needed. Another acoustic survey of the grounds

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1104-407: A major fire, forced a shutdown. A subsequent scandal involving a cover-up of the scope of the accident delayed its restart until May 6, 2010, with renewed criticality reached on May 8, 2010. In August 2010 another accident, involving dropped machinery, shut down the reactor again. As of June 2011, the reactor had only generated electricity for one hour since its first testing two decades prior. As of

1196-444: A neutron and more likely to undergo fission on neutron absorption than isotopes with an even number of neutrons. Plutonium-241 is a beta emitter with a half-life of 14.3 years, corresponding to a decay of about 5% of Pu nuclei over a one-year period. This decay has a Q-value of 20.78 ± 0.17 keV and a mean of 5.227 ± 0.043 keV , and does not emit gamma rays . The longer spent nuclear fuel waits before reprocessing ,

1288-466: A nutrient for animals including humans. Sodium is an essential element for all animals and some plants. Sodium ions are the major cation in the extracellular fluid (ECF) and as such are the major contributor to the ECF osmotic pressure . Animal cells actively pump sodium ions out of the cells by means of the sodium–potassium pump , an enzyme complex embedded in the cell membrane , in order to maintain

1380-528: A rare alpha decay branch to uranium-237 , occurring in about 0.002% of decays. With a Q-value of 5.055 ± 0.005 MeV , it can emit Auger electrons and associated X-rays, unlike the beta-decay process. Americium has lower valence and lower electronegativity than plutonium, neptunium or uranium , so in most nuclear reprocessing , americium tends to fractionate with the alkaline fission products – lanthanides , strontium , caesium , barium , yttrium – rather than with other actinides. Americium

1472-888: A result, sodium usually forms ionic compounds involving the Na cation. Metallic sodium is generally less reactive than potassium and more reactive than lithium . Sodium metal is highly reducing, with the standard reduction potential for the Na /Na couple being −2.71 volts, though potassium and lithium have even more negative potentials. Sodium compounds are of immense commercial importance, being particularly central to industries producing glass , paper , soap , and textiles . The most important sodium compounds are table salt (Na Cl ), soda ash (Na 2 CO 3 ), baking soda (Na HCO 3 ), caustic soda (NaOH), sodium nitrate (Na NO 3 ), di- and tri- sodium phosphates , sodium thiosulfate (Na 2 S 2 O 3 ·5H 2 O), and borax (Na 2 B 4 O 7 ·10H 2 O). In compounds, sodium

1564-495: A result, the committee has established Adequate Intake (AI) levels instead, as follows. The sodium AI for infants of 0–6 months is established at 110 mg/day, 7–12 months: 370 mg/day; for children 1–3 years: 800 mg/day, 4–8 years: 1,000 mg/day; for adolescents: 9–13 years – 1,200 mg/day, 14–18 years 1,500 mg/day; for adults regardless of their age or sex: 1,500 mg/day. Sodium chloride ( NaCl ) contains approximately 39.34% of elemental sodium ( Na )

1656-421: A roughly ten-times higher concentration of sodium ions outside the cell than inside. In nerve cells , the sudden flow of sodium ions into the cell through voltage-gated sodium channels enables transmission of a nerve impulse in a process called the action potential . Sodium at standard temperature and pressure is a soft silvery metal that combines with oxygen in the air, forming sodium oxides . Bulk sodium

1748-416: A senior NRA official, told NHK at the beginning of a 3-week regular safety check that he could not say when test runs would be permitted to start. He would first need to examine how safety checks are conducted and whether adequate measures are in place to avoid a repeat of earlier problems. JAEA had hoped the ban would be lifted by the end of March 2015. On 5 March 2012 a group of seismic researchers revealed

1840-461: A slight radiation hazard; the radioactivity stops within a few days after removal from the reactor. If a reactor needs to be shut down frequently, NaK is used. Because NaK is a liquid at room temperature, the coolant does not solidify in the pipes. In this case, the pyrophoricity of potassium requires extra precautions to prevent and detect leaks. Another heat transfer application is poppet valves in high-performance internal combustion engines;

1932-408: A strong reducing agent, forms upon mixing Na and naphthalene in ethereal solutions. Sodium forms alloys with many metals, such as potassium, calcium , lead , and the group 11 and 12 elements. Sodium and potassium form KNa 2 and NaK . NaK is 40–90% potassium and it is liquid at ambient temperature . It is an excellent thermal and electrical conductor. Sodium-calcium alloys are by-products of

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2024-486: A visit to the plant, nuclear disaster minister Goshi Hosono said that scrapping the Monju-fast-breeder reactor was an option that would be given serious thought. Politicians and private sector experts of the ruling Democratic Party of Japan made proposals for a thorough operational and budgetary review in the government's energy policy screening session earlier in the week before his visit. On 21 December 2016,

2116-634: Is a chemical element ; it has symbol   Na (from Neo-Latin natrium ) and atomic number  11. It is a soft, silvery-white, highly reactive metal . Sodium is an alkali metal , being in group 1 of the periodic table. Its only stable isotope is Na. The free metal does not occur in nature and must be prepared from compounds. Sodium is the sixth most abundant element in the Earth's crust and exists in numerous minerals such as feldspars , sodalite , and halite (NaCl). Many salts of sodium are highly water-soluble: sodium ions have been leached by

2208-460: Is an isotope of plutonium formed when plutonium-240 captures a neutron . Like some other plutonium isotopes (especially Pu), Pu is fissile , with a neutron absorption cross section about one-third greater than that of Pu, and a similar probability of fissioning on neutron absorption, around 73%. In the non-fission case, neutron capture produces plutonium-242 . In general, isotopes with an odd number of neutrons are both more likely to absorb

2300-457: Is dissolved in ammonia solution, it can be used to reduce alkynes to trans- alkenes . Lasers emitting light at the sodium D line are used to create artificial laser guide stars that assist in the adaptive optics for land-based visible-light telescopes. Liquid sodium is used as a heat transfer fluid in sodium-cooled fast reactors because it has the high thermal conductivity and low neutron absorption cross section required to achieve

2392-456: Is less electropositive than sodium, no calcium will be deposited at the cathode. This method is less expensive than the previous Castner process (the electrolysis of sodium hydroxide ). If sodium of high purity is required, it can be distilled once or several times. The market for sodium is volatile due to the difficulty in its storage and shipping; it must be stored under a dry inert gas atmosphere or anhydrous mineral oil to prevent

2484-531: Is seen in any whose surfaces are cool enough for sodium to exist in atomic form (rather than ionised). This corresponds to stars of roughly F-type and cooler. Many other stars appear to have a sodium absorption line, but this is actually caused by gas in the foreground interstellar medium . The two can be distinguished via high-resolution spectroscopy, because interstellar lines are much narrower than those broadened by stellar rotation . Sodium has also been detected in numerous Solar System environments, including

2576-462: Is stable. Na is created in the carbon-burning process in stars by fusing two carbon atoms together; this requires temperatures above 600 megakelvins and a star of at least three solar masses. Two radioactive , cosmogenic isotopes are the byproduct of cosmic ray spallation : Na has a half-life of 2.6 years and Na, a half-life of 15 hours; all other isotopes have a half-life of less than one minute. Two nuclear isomers have been discovered,

2668-549: Is the principal source of sodium ( Na ) in the diet, and is used as seasoning and preservative in such commodities as pickled preserves and jerky ; for Americans, most sodium chloride comes from processed foods . Other sources of sodium are its natural occurrence in food and such food additives as monosodium glutamate (MSG), sodium nitrite , sodium saccharin, baking soda (sodium bicarbonate), and sodium benzoate . The U.S. Institute of Medicine set its tolerable upper intake level for sodium at 2.3 grams per day, but

2760-534: Is therefore not recycled into nuclear fuel unless special efforts are made. In a thermal reactor , Am captures a neutron to become americium -242, which quickly becomes curium -242 (or, 17.3% of the time, Pu) via beta decay . Both Cm and Pu are much less likely to absorb a neutron, and even less likely to fission; however, Cm is short-lived (half-life 160 days) and almost always undergoes alpha decay to Pu rather than capturing another neutron. In short, Am needs to absorb two neutrons before again becoming

2852-622: Is to melt them together and another is to deposit sodium electrolytically on molten lead cathodes. NaPb 3 , NaPb, Na 9 Pb 4 , Na 5 Pb 2 , and Na 15 Pb 4 are some of the known sodium-lead alloys. Sodium also forms alloys with gold (NaAu 2 ) and silver (NaAg 2 ). Group 12 metals ( zinc , cadmium and mercury ) are known to make alloys with sodium. NaZn 13 and NaCd 2 are alloys of zinc and cadmium. Sodium and mercury form NaHg, NaHg 4 , NaHg 2 , Na 3 Hg 2 , and Na 3 Hg. Because of its importance in human health, salt has long been an important commodity. In medieval Europe,

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2944-628: Is usually ionically bonded to water and anions and is viewed as a hard Lewis acid . Most soaps are sodium salts of fatty acids . Sodium soaps have a higher melting temperature (and seem "harder") than potassium soaps. Like all the alkali metals , sodium reacts exothermically with water. The reaction produces caustic soda ( sodium hydroxide ) and flammable hydrogen gas. When burned in air, it forms primarily sodium peroxide with some sodium oxide . Sodium tends to form water-soluble compounds, such as halides , sulfates , nitrates , carboxylates and carbonates . The main aqueous species are

3036-469: Is usually stored in oil or an inert gas. Sodium metal can be easily cut with a knife. It is a good conductor of electricity and heat. Due to having low atomic mass and large atomic radius, sodium is third-least dense of all elemental metals and is one of only three metals that can float on water, the other two being lithium and potassium. The melting (98 °C) and boiling (883 °C) points of sodium are lower than those of lithium but higher than those of

3128-698: The Japan Atomic Energy Agency applied for approval of its decommissioning plan by the Nuclear Regulation Authority . Decommissioning and dismantling are planned to be completed by 2047 and is expected to cost ¥ 375 billion. On December 8, 1995, the reactor suffered an accident rated level 1 on the International Nuclear Event Scale (INES). Intense vibration caused a thermowell inside a pipe carrying sodium coolant to break, possibly at

3220-611: The Mihama Nuclear Power Plant and the Monju fast breeder reactor could also be affected by a possible earthquake caused by the Urazoko fault. On 17 July 2013 a commission of five experts led by NRA commissioner Kunihiko Shimazaki started the investigations on the geological activity of 8 zones of crushed rock under the reactor. Whether these old faults could move in conjunction with the active fault situated half

3312-529: The Shinkansen in turn for the restart of the plant. Monju achieved criticality on May 8, at 10:36 AM JST. Test runs were to continue until 2013, at which point the reactor could have started to feed power into the electric grid, beginning "full fledged" operation. On August 26, 2010, a 3.3- tonne "In‐Vessel Transfer Machine" fell into the reactor vessel when being removed after a scheduled fuel replacement operation. On October 13, 2010, an unsuccessful attempt

3404-595: The Sun . The line was first studied in 1814 by Joseph von Fraunhofer during his investigation of the lines in the solar spectrum, now known as the Fraunhofer lines . Fraunhofer named it the "D" line, although it is now known to actually be a group of closely spaced lines split by a fine and hyperfine structure . The strength of the D ;line allows its detection in many other astronomical environments. In stars, it

3496-472: The electrolysis of sodium hydroxide . In 1809, the German physicist and chemist Ludwig Wilhelm Gilbert proposed the names Natronium for Humphry Davy's "sodium" and Kalium for Davy's "potassium". The chemical abbreviation for sodium was first published in 1814 by Jöns Jakob Berzelius in his system of atomic symbols, and is an abbreviation of the element's Neo-Latin name natrium , which refers to

3588-467: The exospheres of Mercury and the Moon , and numerous other bodies. Some comets have a sodium tail , which was first detected in observations of Comet Hale–Bopp in 1997. Sodium has even been detected in the atmospheres of some extrasolar planets via transit spectroscopy . Employed in rather specialized applications, about 100,000 tonnes of metallic sodium are produced annually. Metallic sodium

3680-558: The sixth most abundant element on Earth and the fourth most abundant metal, behind aluminium , iron , calcium , and magnesium and ahead of potassium. Sodium's estimated oceanic abundance is 10.8 grams per liter. Because of its high reactivity, it is never found as a pure element. It is found in many minerals, some very soluble, such as halite and natron , others much less soluble, such as amphibole and zeolite . The insolubility of certain sodium minerals such as cryolite and feldspar arises from their polymeric anions, which in

3772-523: The Egyptian natron , a natural mineral salt mainly consisting of hydrated sodium carbonate. Natron historically had several important industrial and household uses, later eclipsed by other sodium compounds. Sodium imparts an intense yellow color to flames. As early as 1860, Kirchhoff and Bunsen noted the high sensitivity of a sodium flame test , and stated in Annalen der Physik und Chemie : In

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3864-570: The JAEA in August 2010. Before this he was a professor at the University of Tokyo and the chairman of the former Nuclear Safety Commission. Yonezo Tsujikura, vice president of the JAEA, served as acting president until a successor was chosen. At the end of the fiscal year 2011, a budget of US$ 29 million was requested to continue the Monju project. This money would cover the costs of maintenance and

3956-529: The JAEA, with safety as a top priority. Former functions of Matsuura: Present functions: During safety inspections conducted by the NRA between 3 and 21 June 2013, it was revealed that the safety inspections on another 2,300 pieces of equipment had been omitted by JAEA. In 2014 more uninspected equipment was discovered, and more than 100 improper corrections to inspection records found, leading to concerns that inspection reports were being falsified. Again in 2015 it

4048-597: The Japanese government confirmed the closure and decommissioning of the Monju reactor, with the suggestion that this would cost at least ¥375 billion. The decommissioning of Monju is planned to take 30 years. The Japanese regulator, the Nuclear Regulation Authority , accepted the plan in March 2018. The phases of the plan are: Despite its intention to close the Monju facility, the Cabinet appeared to reaffirm its commitment to

4140-487: The Monju reactor. This decision was met with resistance by the public, resulting in a series of court battles. On January 27, 2003, the Nagoya High Court's Kanazawa branch made a ruling reversing its earlier 1983 approval to build the reactor, but then on May 30, 2005, Japan's Supreme Court gave the green light to reopen the Monju reactor. The nuclear fuel was replaced for the restart. The original fuel loaded

4232-405: The NRA would block the reactivation of the reactor. In reaction to this Suzuki told reporters, "It takes nearly one year for preparation and it is physically quite difficult (to restart the reactor before March 2013)." Because the criticism of the NRA on the sloppy safety controls Atsuyuki Suzuki resigned as President of JAEC on 17 May. Although the resignation was accepted by the government, the move

4324-786: The Science and Technology ministry explained their decision not to start the test run at meetings in the city of Tsuruga and Fukui Prefecture . The local Fukui edition of the Asahi Shinbun reported on June 22, 2012 that the reactor would restart in July 2012. After it was revealed in November 2012, that regular safety checks had been omitted, the Nuclear Regulation Authority ordered JAEA to change its maintenance rules and inspection plans. JAEA had failed to perform periodical safety checks on nearly 10,000 out of 39,000 pieces of equipment at

4416-469: The action of water from the Earth's minerals over eons, and thus sodium and chlorine are the most common dissolved elements by weight in the oceans. Sodium was first isolated by Humphry Davy in 1807 by the electrolysis of sodium hydroxide . Among many other useful sodium compounds, sodium hydroxide ( lye ) is used in soap manufacture , and sodium chloride ( edible salt ) is a de-icing agent and

4508-689: The aquo complexes [Na(H 2 O) n ] , where n = 4–8; with n = 6 indicated from X-ray diffraction data and computer simulations. Direct precipitation of sodium salts from aqueous solutions is rare because sodium salts typically have a high affinity for water. An exception is sodium bismuthate (NaBiO 3 ), which is insoluble in cold water and decomposes in hot water. Because of the high solubility of its compounds, sodium salts are usually isolated as solids by evaporation or by precipitation with an organic antisolvent, such as ethanol ; for example, only 0.35 g/L of sodium chloride will dissolve in ethanol. A crown ether such as 15-crown-5 may be used as

4600-572: The authorities, but the next day the Nuclear Regulation Authority and local governments were informed about the incident. However it was not made public. On 31 May 2013 science and technology minister Hakubun Shimomura announced that Shojiro Matsuura, (77 years) the former chairman of the Nuclear Safety Commission, would be the next president of JAEA on Monday 3 June. In this function he would reorganize

4692-715: The average person in the United States consumes 3.4 grams per day. The American Heart Association recommends no more than 1.5 g of sodium per day. The Committee to Review the Dietary Reference Intakes for Sodium and Potassium, which is part of the National Academies of Sciences, Engineering, and Medicine, has determined that there isn't enough evidence from research studies to establish Estimated Average Requirement (EAR) and Recommended Dietary Allowance (RDA) values for sodium. As

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4784-555: The calls to abolish this reactor were growing after the nuclear accident at Fukushima. As the accident at the Fukushima Daiichi power plant made it difficult, if not impossible, to build new nuclear power plants, the government panel would also review subsidies for localities with atomic power plants as well as functions of related entities such as the Japan Atomic Energy Agency. On 27 November, after

4876-423: The case of feldspar is a polysilicate. In the universe, sodium is the 15th most abundant element with a 20,000 parts-per-billion abundance, making sodium 0.002% of the total atoms in the universe. Atomic sodium has a very strong spectral line in the yellow-orange part of the spectrum (the same line as is used in sodium-vapour street lights ). This appears as an absorption line in many types of stars, including

4968-402: The costs of the test run, planned in the summer of 2012. On 20 November a seven-member Japanese government commission decided that the future of the Monju reactor should be thoroughly reviewed before a decision could be made for this 2012 budget. Some members of the commission thought that there would be little public support for restarting the fast breeder project, and that it was uncertain that

5060-719: The coverup, Shigeo Nishimura, committed suicide by leaping from the roof of a Tokyo hotel. Nishimura was deputy general manager of the general affairs department of the Power Reactor and the Nuclear Fuel Development Corporation, the Government concern that ran the country's prototype fast-breeder reactor. Officials said Nishimura was not involved in the cover-up but was distressed by evidence he had unearthed. On November 24, 2000, Japan Atomic Energy Agency announced their intention to restart

5152-431: The electrolytic production of sodium from a binary salt mixture of NaCl-CaCl 2 and ternary mixture NaCl-CaCl 2 -BaCl 2 . Calcium is only partially miscible with sodium, and the 1–2% of it dissolved in the sodium obtained from said mixtures can be precipitated by cooling to 120 °C and filtering. In a liquid state, sodium is completely miscible with lead. There are several methods to make sodium-lead alloys. One

5244-419: The end of 2010, total funds spent on the reactor amounted to ¥1.08 trillion. An estimated ¥160–170 billion would be needed to continue to operate the reactor for another 10 years. As of 2014, the plant had cost ¥ 1 trillion ($ 9.8 billion). A final decision on the project (e.g. to decommission or extend funding) was due by end 2016, and a decision to close the facility was made in December 2016. In December 2017

5336-420: The formation of a surface layer of sodium oxide or sodium superoxide . Though metallic sodium has some important uses, the major applications for sodium use compounds; millions of tons of sodium chloride , hydroxide , and carbonate are produced annually. Sodium chloride is extensively used for anti-icing and de-icing and as a preservative; examples of the uses of sodium bicarbonate include baking, as

5428-452: The go ahead from both entities, JAEA started criticality testing, after which it took some months before commercial operation could resume – as for any new nuclear plant. Operators started withdrawing control rods on May 6, 2010, marking the restart of the plant. The Fukui Prefecture governor, Issei Nishikawa asked the METI for additional stimulus to the prefecture including an expansion of

5520-435: The heavier alkali metals potassium, rubidium, and caesium, following periodic trends down the group. These properties change dramatically at elevated pressures: at 1.5  Mbar , the color changes from silvery metallic to black; at 1.9 Mbar the material becomes transparent with a red color; and at 3 Mbar, sodium is a clear and transparent solid. All of these high-pressure allotropes are insulators and electrides . In

5612-621: The length of the Urasoko fault to 35 km. Computer simulations calculating the length of a fault based on its displacement, showed the Urasoko fault to be 39 km long, a result close to the length estimated by the sonic survey data, and the fault could cause some 5 meter displacement when activated together with other faults. Yuichi Sugiyama, the leader of this research group of the National Institute of Advanced Industrial Science and Technology, warned that – as other faults on

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5704-517: The longer-lived one being Na with a half-life of around 20.2 milliseconds. Acute neutron radiation, as from a nuclear criticality accident , converts some of the stable Na in human blood to Na; the neutron radiation dosage of a victim can be calculated by measuring the concentration of Na relative to Na. Sodium atoms have 11 electrons, one more than the stable configuration of the noble gas neon . The first and second ionization energies are 495.8 kJ/mol and 4562 kJ/mol, respectively. As

5796-434: The more Pu decays to americium-241 , which is nonfissile (although fissionable by fast neutrons ) and an alpha emitter with a half-life of 432 years; Am is a major contributor to the radioactivity of nuclear waste on a scale of hundreds or thousands of years. In its fully ionized state, the beta-decay half-life of Pu decreases to 4.2 days, but only bound-state beta decay is possible. Plutonium-241 also has

5888-466: The need for large quantities of sodium. A related process based on the reduction of sodium hydroxide was developed in 1886. Sodium is now produced commercially through the electrolysis of molten sodium chloride (common salt), based on a process patented in 1924. This is done in a Downs cell in which the NaCl is mixed with calcium chloride to lower the melting point below 700 °C. As calcium

5980-529: The newly formed Mitsubishi FBR Systems company. However, in 2014 Japan agreed to cooperate in developing the emergency reactor cooling system, and in a few other areas, with the French ASTRID demonstration sodium-cooled fast breeder reactor, which was subsequently cancelled in August 2019. As of 2016, France was seeking the full involvement of Japan in the ASTRID development. Sodium Sodium

6072-620: The oceanic faults were not taken into account by NISA and JAP in the assessment of the safety of the Tsuruga nuclear power plant. Analysis of sonic survey and other data provided by Japan Atomic Power analysed by a panel of experts of Nuclear and Industrial Safety Agency showed the presence of multiple faults existing within 2 to 3 km from the Urasoko fault . According to Sugiyama, a member of this group of scientists, these faults were highly likely to be activated together, and this would extend

6164-435: The plant before the deadlines were met. Half May 2013 not all details were worked out, and under the rules set by the NRA, it was not allowed to change nuclear fuel rods or move the control rods. Therefore, the restart of the reactor was not permitted. On 16 May 2013 the NRA ordered JAEA President Atsuyuki Suzuki to comply with their decisions and planned a meeting on 23 May to explain their reasoning, making it very likely that

6256-402: The plant repurposed into a research centre for handling spent nuclear fuel . On 29 May 2013, the NRA announced that JAEA was prohibited from restarting the fast breeder reactor, describing the safety culture at the plant as "deteriorated", because the problems at the plant were not addressed, and the staff were aware of the delayed inspections. The NRA said that before it could plan a restart of

6348-441: The positive charge counterbalanced by electrons as anions ; cryptands permit the isolation of these complexes as crystalline solids. Sodium forms complexes with crown ethers, cryptands and other ligands. For example, 15-crown-5 has a high affinity for sodium because the cavity size of 15-crown-5 is 1.7–2.2 Å, which is enough to fit the sodium ion (1.9 Å). Cryptands, like crown ethers and other ionophores , also have

6440-490: The possibility of a 7.4M (or even more potent) earthquake under the Tsuruga Nuclear Powerplant. Before this date the Japanese governmental Earthquake Research Committee and Japan Atomic Power had calculated that the Urasoko fault under the plant, combined with other faults connected to it, was around 25 km long. and could cause a 7.2M quake and a 1.7 meter displacement. On top of this, the presence of

6532-456: The pressure increases. By itself or with potassium , sodium is a desiccant ; it gives an intense blue coloration with benzophenone when the desiccate is dry. In organic synthesis , sodium is used in various reactions such as the Birch reduction , and the sodium fusion test is conducted to qualitatively analyse compounds. Sodium reacts with alcohols and gives alkoxides , and when sodium

6624-545: The reactor could be taken into commercial service in 2050 as originally planned. Other members said that the Monju project should be stopped completely, and that all efforts should be put into the international fusion reactor project ITER instead. Decisions about the 2012 budget would be taken after the discussions in a panel of cabinet members about the nuclear policy of Japan, including the fast breeder reactor project, would be complete. Reports in 2012 indicated that plans to generate electricity at Monju would be abandoned, and

6716-532: The reactor's auxiliary building; in August 2009 it was announced that restart might be in February 2010. In February 2010, JAEA obtained official approval to restart the reactor from the Japanese Government . The restart was definitely scheduled for the end of March. In late February, JAEA requested Fukui Prefecture and Tsuruga City for deliberations aimed at resuming test operation. Having obtained

6808-415: The reactor, JAEA must allocate appropriate funds and human resources to rebuild a maintenance and management system to prevent the recurrence of coolant leakages and other problems. The NRA also announced that an assessment would be made of whether geologic faults at the location of the Monju facility are active. It had similar plans for surveys at six facilities all over Japan. On 2 March 2015 Noboru Hirose,

6900-672: The reactor, in which the reactor's output would be raised to 40 percent of its capacity by the end of March 2012, was postponed on September 29, 2011, by the Japanese Government because the uncertainty over the future of nuclear energy. After the disaster in Fukushima , the Atomic Energy Commission of Japan made a start with a review of Japan's long term energy policy. An outline of this policy would be published within 12 months. On September 30, officials of

6992-403: The sodium heater, which keeps the sodium molten as a secondary coolant, ceased operating for half an hour from about 4:30 p.m. The power supply was checked, but insufficient information in the service manual caused the heater to stop, causing a fall of about 40 C from 200 C of the sodium temperature. Under the internal rules of JAEA, the failure was regarded a too minor incident to report it to

7084-499: The south side of the Urasoko fault could become activated together – "The worst case scenario should be taken into consideration" According to the experts there were many other faults located under one reactor on the west side of the Urasoku fault that could move also simultaneously. If this would be confirmed, the location of the Tsuruga nuclear plant would be disqualified. On 6 March 2012 NISA asked Japan Atomic Power Co. to reassess

7176-460: The system over to manual operations, but a full operational shutdown was not ordered until around 9:00 p.m., after the fumes were detected. When investigators located the source of the spill they found as much as three tons of solidified sodium. The leak occurred in the plant's secondary cooling system, so the sodium was not radioactive . However, there was massive public outrage in Japan when it

7268-459: The three emergency generators unusable. During the monthly testing of the emergency diesel generators, staff forgot to close six of the twelve valves they had opened before testing, releasing thick black smoke. JAERI reported it to the Nuclear Regulation Authority as a breach of security regulations. On Monday 16 September 2013 before 3 a.m. the data transmission of the reactor stopped to the government's Emergency Response Support System. Whether this

7360-600: The total mass. This means that 1 gram of sodium chloride contains approximately 393.4 mg of elemental sodium. For example, to find out how much sodium chloride contains 1500 mg of elemental sodium (the value of 1500 mg sodium is the adequate intake (AI) for an adult), we can use the proportion: Solving for x gives us the amount of sodium chloride that contains 1500 mg of elemental sodium: This mean that 3812.91 mg of sodium chloride contain 1500 mg of elemental sodium. Plutonium-241 Plutonium-241 ( Pu or Pu-241 )

7452-476: The valve stems are partially filled with sodium and work as a heat pipe to cool the valves. In humans, sodium is an essential mineral that regulates blood volume, blood pressure, osmotic equilibrium and pH . The minimum physiological requirement for sodium is estimated to range from about 120 milligrams per day in newborns to 500 milligrams per day over the age of 10. Sodium chloride , also known as edible salt or table salt (chemical formula NaCl ),

7544-612: The worst-case scenario for earthquakes at the Tsuruga Nuclear Power Plant . What damage this could do to the buildings on the site, because the Urazoko fault, running around 250 meters from the reactor buildings, could have a serious impact on the earthquake resistance of the power plant. NISA was also planning to send similar instructions to two other nuclear power plant operators in the Fukui area: Kansai Electric Power Company , and Japan Atomic Energy Agency . Because

7636-530: Was a surprise, because on May 16 Susuki had spoken on a meeting in the Japanese parliament, the Diet, and to the NRA secretariat and had pleaded to restore the public's trust in the JAEC. The NRA commented, that Suzuki's resignation had not solved fundamental problems and that there was a need to restructure the JAEA as an organization. Suzuki (born 1942) was an authority on the nuclear fuel cycle, and became President of

7728-433: Was caused by Typhoon Man-yi , the powerful typhoon that went through Japan that day, was unknown. At that moment it was not possible to restore the connection, because the reactor site in Tsuruga was inaccessible due to mudslides and fallen trees caused by the typhoon. On August 3, 2016, it was discovered that an alert triggered on November 19, 2015, when the quality of the water in a spent nuclear fuel rod pool deteriorated,

7820-473: Was discovered that regular degradation assessments measuring the thickness of sodium cooling pipes had not been carried out since 2007. On 16 February 2012 NISA reported that a sodium-detector malfunctioned. About 3 p.m local time the alarm went off. Additionally, a ventilator that should cool a pipe stopped. According to NISA no leakage was found, and there was no damage to the environment. Repairs were planned. On 30 April 2013 an operating error rendered two of

7912-519: Was first produced commercially in the late nineteenth century by carbothermal reduction of sodium carbonate at 1100 °C, as the first step of the Deville process for the production of aluminium: The high demand for aluminium created the need for the production of sodium. The introduction of the Hall–Héroult process for the production of aluminium by electrolysing a molten salt bath ended

8004-400: Was ignored until April 2016 and rectified only the next month. In September 2011 the ministry of education, science and technology asked for the fiscal year of 2012 only 20 to 30 percent of the budget to maintain and manage the Monju reactor for the year 2011. The uncertainty about Japan's future energy policy caused the ministry to conclude that the project could not proceed. The test run of

8096-484: Was made to retrieve the machine. The JAEA tried to recover the device used in fuel exchange but failed as it had become misshaped, preventing its retrieval through the upper lid. The JAEA began preparatory engineering work on May 24, 2011 to set up equipment to be used to retrieve the IVTM that fell inside the vessel. The fallen device was successfully retrieved from the reactor vessel on June 23, 2011. On Sunday 2 June 2012

8188-422: Was mixed plutonium-uranium oxide with plutonium content of around 15–20%, but by 2009, due to natural radioactive decay, the fuel had only half of the original plutonium-241 content. This made achieving criticality impossible, requiring fuel replacement. The restart was scheduled for October 2008, having been moved back five months. A restart date of February 2009 was again delayed due to the discovery of holes in

8280-484: Was planned by Japan Atomic Energy Agency and a geological examination to determine the age of the clay and stones in the faults. This could take a couple of months to finish, The assessment was planned at the end of August 2013. On 21 October 2011 the Japanese government appointed a commission to study ways to cut wasteful expenditures, one possibility being decommissioning the Monju prototype fast breeder reactor. The Government Revitalization Unit took up this issue, because

8372-458: Was revealed that Power Reactor and Nuclear Fuel Development Corporation (PNC), the semi-governmental agency then in charge of Monju, had tried to cover up the extent of the accident and resulting damage. This coverup included falsifying reports and the editing of a videotape taken immediately after the accident, as well as issuing a gag order that aimed to stop employees revealing that tapes had been edited. The official in charge of investigating

8464-554: Was the making of tetraethyllead and titanium metal; because of the move away from TEL and new titanium production methods, the production of sodium declined after 1970. Sodium is also used as an alloying metal, an anti-scaling agent , and as a reducing agent for metals when other materials are ineffective. Note the free element is not used as a scaling agent, ions in the water are exchanged for sodium ions. Sodium plasma ("vapor") lamps are often used for street lighting in cities, shedding light that ranges from yellow-orange to peach as

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