Caesium is a chemical element with the symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of 28.5 °C (83.3 °F), which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoric and reacts with water even at −116 °C (−177 °F). It is the least electronegative element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. Caesium-137, a fission product, is extracted from waste produced by nuclear reactors. It has the largest atomic radius of all elements whose radii have been measured or calculated, at about 260 picometers.
Francium is a chemical element with the symbol Fr and atomic number 87. It is extremely radioactive; its most stable isotope, francium-223, has a half-life of only 22 minutes. It is the second-most electropositive element, behind only caesium, and is the second rarest naturally occurring element. Francium's isotopes decay quickly into astatine, radium, and radon. The electronic structure of a francium atom is [Rn] 7s1; thus, the element is classed as an alkali metal.
Prachinburi province is one of Thailand's seventy-seven provinces (changwat), it lies in eastern Thailand. Neighboring provinces are Nakhon Ratchasima, Sa Kaeo, Chachoengsao, and Nakhon Nayok.
The Goiânia accident[ɡojˈjɐniɐ] was a radioactive contamination accident that occurred on September 13, 1987, in Goiânia, Goiás, Brazil, after an unsecured radiotherapy source was stolen from an abandoned hospital site in the city. It was subsequently handled by many people, resulting in four deaths. About 112,000 people were examined for radioactive contamination and 249 of them were found to have been contaminated.
Nuclear fission products are the atomic fragments left after a large atomic nucleus undergoes nuclear fission. Typically, a large nucleus like that of uranium fissions by splitting into two smaller nuclei, along with a few neutrons, the release of heat energy, and gamma rays. The two smaller nuclei are the fission products..
Caesium chloride or cesium chloride is the inorganic compound with the formula CsCl. This colorless salt is an important source of caesium ions in a variety of niche applications. Its crystal structure forms a major structural type where each caesium ion is coordinated by 8 chloride ions. Caesium chloride dissolves in water. CsCl changes to NaCl structure on heating. Caesium chloride occurs naturally as impurities in carnallite, sylvite and kainite. Less than 20 tonnes of CsCl is produced annually worldwide, mostly from a caesium-bearing mineral pollucite.
Caesium (55Cs) has 40 known isotopes, making it, along with barium and mercury, one of the elements with the most isotopes. The atomic masses of these isotopes range from 112 to 151. Only one isotope, 133Cs, is stable. The longest-lived radioisotopes are 135Cs with a half-life of 2.3 million years, 137
Cs
with a half-life of 30.1671 years and 134Cs with a half-life of 2.0652 years. All other isotopes have half-lives less than 2 weeks, most under an hour.
Caesium-137, cesium-137 (US), or radiocaesium, is a radioactive isotope of caesium that is formed as one of the more common fission products by the nuclear fission of uranium-235 and other fissionable isotopes in nuclear reactors and nuclear weapons. Trace quantities also originate from spontaneous fission of uranium-238. It is among the most problematic of the short-to-medium-lifetime fission products. Caesium-137 has a relatively low boiling point of 671 °C (1,240 °F) and easily becomes volatile when released suddenly at high temperature, as in the case of the Chernobyl nuclear accident and with atomic explosions, and can travel very long distances in the air. After being deposited onto the soil as radioactive fallout, it moves and spreads easily in the environment because of the high water solubility of caesium's most common chemical compounds, which are salts. Caesium-137 was discovered by Glenn T. Seaborg and Margaret Melhase.
Environmental radioactivity is produced by radioactive materials in the human environment. While some radioisotopes, such as strontium-90 (90Sr) and technetium-99 (99Tc), are only found on Earth as a result of human activity, and some, like potassium-40 (40K), are only present due to natural processes, a few isotopes, e.g. tritium (3H), result from both natural processes and human activities. The concentration and location of some natural isotopes, particularly uranium-238 (238U), can be affected by human activity.
General elections were held in Thailand on 23 December 2007. They were the first elections after the Council for National Security, a military junta, had overthrown Thailand's elected government and abrogated the constitution on 19 September 2006. The junta had canceled general elections scheduled for October 2006 and promised new elections within 12 months. The Constitutional Tribunal then outlawed the Thai Rak Thai party, the largest political party in Thailand, and banned TRT executives from contesting in the elections for five years. After their political party had been dissolved, the former TRT members regrouped under the band of People's Power Party (PPP) led by Samak Sundaravej, a seasoned politician. Following its formation, the junta issued a classified order to suppress the activities of the PPP and to frame it for lèse majesté. The order was leaked to the public, leading to a complaint towards the Election Commission from the PPP. However, the Election Commission dismissed the complaint on the grounds that the Council for National Security (CNS) had granted itself immunity in the 2007 Constitution of Thailand.
On 11 March 2011, a nuclear accident occurred at the Fukushima Daiichi Nuclear Power Plant in Ōkuma, Fukushima, Japan. The proximate cause of the disaster was the Tōhoku earthquake and tsunami, which remains the most powerful earthquake ever recorded in Japan. The earthquake triggered a powerful tsunami, with 13- to 14-meter-high waves damaging the nuclear power plant's emergency diesel generators, leading to a loss of electric power. The result was the most severe nuclear accident since the Chernobyl disaster in 1986, classified as level seven on the International Nuclear Event Scale (INES) after initially being classified as level five, and thus joining Chernobyl as the only other accident to receive such classification.
The radiation effects from the Fukushima Daiichi nuclear disaster are the observed and predicted effects as a result of the release of radioactive isotopes from the Fukushima Daiichii Nuclear Power Plant following the 2011 Tōhoku 9.0 magnitude earthquake and tsunami. The release of radioactive isotopes from reactor containment vessels was a result of venting in order to reduce gaseous pressure, and the discharge of coolant water into the sea. This resulted in Japanese authorities implementing a 30-km exclusion zone around the power plant and the continued displacement of approximately 156,000 people as of early 2013. The number of evacuees has declined to 49,492 as of March 2018. Large quantities of radioactive particles from the incident, including iodine-131 and caesium-134/137, have since been detected around the world. Substantial levels have been seen in California and in the Pacific Ocean.
A radiation accident occurred in Samut Prakan Province, Thailand in January–February 2000. The accident happened when an insecurely stored unlicensed cobalt-60 radiation source was recovered by scrap metal collectors who, together with a scrapyard worker, subsequently dismantled the container, unknowingly exposing themselves and others nearby to ionizing radiation. Over the following weeks, those exposed developed symptoms of radiation sickness and eventually sought medical attention. The Office of Atomic Energy for Peace (OAEP), Thailand's nuclear regulatory agency, was notified when doctors came to suspect radiation injury, some 17 days after the initial exposure. The OAEP sent an emergency response team to locate and contain the radiation source, which was estimated to have an activity of 15.7 terabecquerels (420 Ci), and was eventually traced to its owner. Investigations found failure to ensure secure storage of the radiation source to be the root cause of the accident, which resulted in ten people being hospitalized for radiation injury, three of whom died, as well as the potentially significant exposure of 1,872 people.
Unit 3 of the Fukushima Daiichi Nuclear Power Plant was one of the reactors in operation on 11 March 2011, when the plant was struck by the tsunami produced by the Tohoku earthquake. In the aftermath, the reactor experienced hydrogen gas explosions and suffered a partial meltdown, along with the other two reactors in operation at the time the tsunami struck, unit 1 and unit 2. Efforts to remove debris and coolant water contaminated with radiation are ongoing and expected to last several decades.
Radioactive waste water has been discharged into the Pacific Ocean since the Fukushima Daiichi nuclear disaster, triggered by the 2011 Tōhoku earthquake and tsunami on 11 March 2011 in Japan. Most of the radioactive materials came from immediate leaks into the atmosphere, 80% of which eventually deposited over the Pacific. Leakage to groundwater has persisted since the disaster and was only first admitted by the nuclear plant in 2013. Water treatment began that year as the "Advanced Liquid Processing System" became operable, which is capable of removing most radionuclides except notably tritium. In 2021, the Japanese cabinet approved the dumping of radioactive water into the Pacific over a course of 30 years. The move faces concerns and criticism from other countries and international organisations.
Military circles of Thailand are subdivisions of the Royal Thai Army. Each military circle governs and supports all military units and personnel in its area. Several military circles are grouped into a military region. A military circle can cover one or more civil provinces.
Following is a list of events and scheduled events in the year 2023 in Thailand. The year 2023 is reckoned as the year 2566 in Buddhist Era, the Thai calendar.
Sometime between 10 and 16 January 2023, a radioactive capsule containing caesium-137 was lost from a truck in Western Australia. The capsule was being transported 1,400 kilometres (870 mi) from Rio Tinto's Gudai-Darri iron ore mine near Newman to a depot in the Perth suburb of Malaga. The Department of Fire and Emergency Services announced to the public on 27 January that the capsule had gone missing, and that the capsule was potentially deadly and could cause burns and radiation sickness. It was discovered on the side of the road near Newman on 1 February.
