FÁRMACO
Es toda sustancia química purificada utilizada en la prevención, diagnóstico, tratamiento, mitigación y cura de una enfermedad; para evitar la aparición de un proceso fisiológico no deseado; o para modificar condiciones fisiológicas con fines específicos.
Un fármaco, de acuerdo con la farmacología, es cualquier sustancia que produce efectos medibles o sensibles en los organismos vivos y que se absorbe, puede transformarse, almacenarse o eliminarse.1
Esta definición se acota a aquellas sustancias de interés clínico, es decir aquellas usadas para la prevención, diagnóstico, tratamiento, mitigación y cura de enfermedades,2 y se prefiere el nombre de tóxico para aquellas sustancias no destinadas al uso clínico pero que pueden ser absorbidas accidental o intencionalmente; y droga para aquellas sustancias de uso social que se ocupan
para modificar estados del ánimo.
Los fármacos pueden ser sustancias creadas por el hombre o producidas por otros organismos y utilizadas por el hombre. De esta forma, hormonas, anticuerpos, interleucinas yvacunas son considerados fármacos al ser administrados en forma farmacéutica.3 En resumen, para que una sustancia biológicamente activa se clasifique como fármaco, debe administrarse al cuerpo de manera e
xógena y con fines médicos.
Los fármacos se expenden y utilizan principalmente en la forma de medicamentos, los cuales contienen el o los fármacos prescritos por un facultativo en conjun
to con excipientes.
Además de la denominación química de un fármaco, los fabricantes de productos farmacéuticos, en conjunto con instituciones científicas y académicas le asignan un nombre clave, llamado nombre genérico del fármaco. Sin embargo, muchas veces el fabricante lo comercializa con un nombre patentado, que puede variar entre distintas naciones, lo cual ha generado una gran confusión respecto de los nombres de los fármacos y medicamentos.
Para resolver esto, las distintas legislaciones han provisto de diversos sistemas de control de los nombres de los fármacos y los medicamentos que se expenden.
Medicamentos
Se entiende por medicamento al estado final bajo el cual se presenta un fármaco para su uso práctico, para la consideración del máximo beneficio terapéutico para el individuo y minimizando los efectos secundarios indeseables.
§ Líquidas:
Solución, jarabe, tintura, infusiones, aerosoles, colirio, inyectables e infusión parenteral, extracto, emulsión, enema, colutorios y gargarismos
§ Sólidas:
Polvos, granulados, tabletas, grageas, cápsula, píldoras o glóbulo homeopático.
§ Semisólidas:
Suspensión, emulsión, pasta, crema o pomada, ungüento, geles, lociones, supositorios, óvulos, jaleas y cremas anticonceptivos y linimentos.
§ Otras:
Nanosuspensión, emplasto, dispositivos transdérmicos, aspersores, inhaladores e implantes.
Los nombres comerciales de los medicamentos varían en muchos países aun cuando posean el mismo fármaco; es por eso que se recurre a utilizar el nombre del medicamento acompañado del nombre del fármaco.
Características de los fármacos
Los fármacos pueden ser sintetizados o extraídos de un organismo vivo, en este último caso, debe ser purificado y/o modificada químicamente, antes de ser considerado como tal. La actividad de un fármaco varia debido a la naturaleza de estos, pero siempre está relacionado con la cantidad ingerida o absorbida. Por ejemplo, los medicamentos oncológicos, que curan el cáncer, son conocidos como ingredientes activos altamente potentes (high potent active ingredients) y se usan en concentraciones muy pequeñas para curar un tipo especial de cáncer. Cada uno de estos causa muchos efectos secundarios y la sobredosis puede afectar negativamente a células sanas, tal es el caso del oxaliplatino, letrozol, cisplatino,anaztrazole, etc.
Fármacos naturales
En fármacos fitosanitarios a base de hierbas, el ingrediente activo puede ser el resultado de la interacción de una variedad de componentes que actúan tanto sobre un agente patógeno y en una variedad de sistemas del cuerpo que participan en la inmunidad. El ingrediente farmacéutico activo puede ser desconocido o podrán existir cofactores , a fin de lograr los objetivos terapéuticos. Una manera como los fabricantes lo han tratado de indicar es la normalización de un marcador compuesto. Sin embargo la normalización no se ha estandarizado aún: las diferentes empresas utilizan diferentes marcadores, o diferentes niveles de los marcadores de la misma, o diferentes métodos de ensayo para los compuestos marcador. Por ejemplo, laHierba de San Juan es a menudo normalizada a la hipericina que ahora se sabe que no es el "ingrediente activo" para el uso de antidepresivos. Otras empresas a normalizar hyperforin o ambos, aunque puede haber unos 24 conocidos activos posible. Muchos herbolarios creen que el ingrediente activo en una planta es la planta en sí.
El herborista y fabricante David Winston señala que cuando los diferentes compuestos elegidos son como "ingredientes activos" para las diferentes hierbas, existe la posibilidad de que los proveedores recibirán un lote inferior (baja de la composición química de marcadores) y mezclar con un lote superior en el deseado marcador para compensar la diferencia. Esto podría resultar en un producto que no tiene toda la gama de bienes que provendría de un bien seleccionadas y cosechadas a base de hierbas fuente.
Categorías terapéuticas
§ Analgésico (contra el dolor)
§ Anestésico (para adormecer a los pacientes en cirugía)
§ Ansiolítico (contra la ansiedad)
§ Antibiótico (contra las infecciones bacterianas)
§ Anticolinérgico (con efectos sobre el sistema nervioso)
§ Anticonceptivo (para prevenir el embarazo)
§ Anticonvulsivo (contra las convulsiones y otros síntomas de la epilepsia)
§ Antidepresivo (contra la depresión)
§ Antihelmíntico (contra las infecciones intestinales provocadas por gusanos y lombrices (helmintiasis))
§ Antihistamínico (contra las alergias)
§ Antineoplásico (contra los tumores (neoplasias))
§ Antiinflamatorio (contra la inflamación)
§ Antiparkinsoniano (contra los síntomas de la enfermedad de Parkinson)
§ Antimicótico (contra los hongos)
§ Antipirético (contra la fiebre)
§ Antipsicótico (contra los síntomas de diferentes tipos de psicosis y de otros padecimientos mentales/emocionales)
§ Antídoto (contra los efectos de los venenos)
§ Broncodilatador (para dilatar los bronquios; útiles en el tratamiento del asma y de la enfermedad pulmonar obstructiva crónica (EPOC))
§ Cardiotónico (para fortalecer el músculo cardíaco)
§ Citostático (o citotóxico o quimioterápico) (para interrumpir la división celular; de utilidad en el tratamiento del cáncer)
§ Hipnótico (para obtener relajación, sedación, tranquilidad o sueño en pacientes con ansiedad o con problemas para dormir)
§ Hormonoterápico (para resolver desequilibrios en el funcionamiento hormonal)
§ Quimioterápico (para el tratamiento de tumores cancerosos)
§ Relajante muscular (para la relajación y el alivio de dolores musculares)
PRINCIPIO ACTIVO
Es la sustancia que produce el efecto para el cual el medicamento fue creado (curar o prevenir enfermedades). Por ejemplo, cuando uno toma un jarabe para la tos, éste tiene una substancia que alivia ese malestar.
El principio activo Amoxicilina , empleado contra las infecciones bacterianas, se encuentra en el medicamento de marca Amoxil . En el caso de los medicamentos genéricos, como se explicará a continuación, adoptan el nombre del principio activo.
TRANSDUCTOR BIOLÓGICO
Estructura capaz de servir como un puente para transmisión de una señal, tal como un segundo mensajero.
MARIHUANA
Los términos cannabis y marihuana, entre muchos otros, hacen referencia a las sustancias psicoactivas que son consumidas de la planta Cannabis sativa con fines recreativos, religiosos y medicinales. De acuerdo con la Organización de las Naciones Unidas, es “la sustancia ilícita más utilizada en el mundo”.2 La regulación legal del cannabis varía dependiendo de los países, existiendo defensores de la despenalización de su consumo3 y, en oposición a estos, defensores de su prohibición.
De la o el cannabis generalmente se consumen las flores hembras que contienen la mayor cantidad de psicoactivos. La extración de laresina de las flores se conoce como hachís.
El compuesto químico psicoactivo predominante en el cannabis es el tetrahidrocannabinol, también conocido por sus siglas, THC. El cannabis contiene más de 400 compuestos químicos diferentes, entre ellos al menos 66 otros cannabinoides como el cannabidiol (CBD), el cannabinol (CBN) y la tetrahidrocannabivarina (THCV), los que tienen distintos efectos en sistema nervioso a los del THC.4
Se ha descubierto que el uso del cannabis data desde el III milenio a. C..5 En el 2004 las Naciones Unidas estimaron que aproximadamente el 4% de la población mundial adulta (162 millones de personas) consume marihuana anualmente, y alrededor del 0,6% (22,5 millones) lo consume a diario.6 A partir de la segunda mitad del siglo XX, el uso, la posesión y la venta de preparados con cannabis que contienen los canabinoides psicoactivos comenzaron a considerarse ilegales en la mayor parte del mundo.7 Desde ese entonces, algunos países han intensificado su control sobre la distribución de la sustancia.
COCAÍNA
La cocaína es un alcaloide que se obtiene de la planta de coca. Es un estimulador del sistema nervioso y supresor del hambre, era usado en medicina como anestésico, incluso en niños, específicamente en cirugías de ojos y nariz pero actualmente está prohibido. A nivel del sistema nervioso central, actúa específicamente como un inhibidor de la recaptación de serotonina-norepinefrina-dopamina, aumentando el efecto de estos neurotransmisores, causando diferentes acciones a nivel sistémico. En la mayoría de los países la cocaína es una droga prohibida.
Se extrae de la planta de la coca rkmn (quechua:kuka), una especie de singular importancia cuyas plantas son cultivadas en América del Sur (Bolivia, Colombia, Perú, norte de Argentina), así como en la isla de Java y en la India. Las hojas de la coca se mastican como estimulante para resistir diferentes inclemencias, tales como el apunamiento o soroche, también llamado mal de las alturas. Dichas hojas poseen 14 alcaloides naturales dentro de los cuales cabe distinguir la blobulina, es un cardiotónico que regula la carencia de oxígeno en el ambiente, mejorando la circulación sanguínea y, como se indicó antes, evitando así el mal de las alturas. Sin embargo, el alcaloide más conocido es la cocaína, el cual, consumido a través de masticar la coca, tiene propiedades anestésicas y analgésicas.
MORFINA
La morfina es una potente droga opiácea usada frecuentemente en medicina como analgésico. La morfina fue bautizada así por el farmacéutico alemán Friedrich Wilhelm Adam Sertürner en honor a Morfeo, el dios griego de los sueños.
La morfina es un alcaloide fenantreno del opio, siendo preparado el sulfato por neutralización con ácido sulfúrico. Es una sustancia controlada, opioide agonista utilizada en premedicación, anestesia, analgesia, tratamiento del dolor asociado a la isquemia miocárdica y para la disnea asociada al fracaso ventricular izquierdo agudo y edema pulmonar. Es un polvo blanco, cristalino, inodoro y soluble en agua.
Su estructura molecular es C17H19NO3 y su nomenclatura IUPAC es (5α, 6α)-Didehidro-4,5-epoxi-17-metilmorfinan-3,6-diol. Se administra en forma sulfatada, con una solubilidad de 60 mg/mL siendo su estructura (C17H19NO3)2 H2SO4 5H20.
ANFETAMINA
La anfetamina es un agente adrenérgico sintético, potente estimulante del sistema nervioso central. La dexanfetamina (dextro-anfetamina), surge de la separación del compuesto racémico (d, l-anfetamina) en sus dos configuraciones ópticas posibles, y la extracción de aquella que corresponda isómero óptico dextrógiro.
La expresión anfetamininas (forma plural de la anterior) tiene al menos dos acepciones posibles. La más restringida, se usa para referir la tríada formada por las sustancias: anfetamina, dexanfetamina y metanfetamina. En tanto que la más general alude también a losestimulantes de tipo anfetamínico (ATS: acrónimo inglés de Amphetamine-Type Stimulants). Los ATS son la familia farmacológica integrada por compuestos con estructura química análoga o derivada de la molécula de anfetamina, con propiedades clínicas similares, y con grado de actividad farmacológica (potencia) comparable. Esta acepción es más frecuente, y es la que utilizaremos en este artículo (salvo indicación en contrario). Habilita para incluir también en el grupo de las sustancias anfetamínicas a estimulantes como elmetilfenidato (análogo estructural) y el dexmetilfenidato; y a derivados químicos con propiedades entactógenas, como el MDMA; yanorexígenas, como el fenproporex, el dietilpropión (anfepramona), la fentermina, la benzfetamina, la fendimetrazina, siendo estas últimas las de menor potencia relativa.
lunes, 7 de noviembre de 2011
lunes, 6 de junio de 2011
History
In 1954, Japan budgeted 230 million yen for nuclear energy, marking the beginning of the program. The Atomic Energy Basic Law limited activities to only peaceful purposes.
The first nuclear reactor in Japan was built by the UK's GEC. In the 1970s the first Light Water Reactors were built in cooperation with American companies. These plants were bought from U.S. vendors such as General Electric or Westinghouse with contractual work done by Japanese companies, who would later get a license themselves to build similar plant designs. Developments in nuclear power since that time has seen contributions from Japanese companies and research institutes on the same level as the other big users of nuclear power.
Robert Jay Lifton has asked how Japan, after its experience with the atomic bombings of Hiroshima and Nagasaki, could "allow itself to draw so heavily on the same nuclear technology for the manufacture of about a third of its energy". He says:
There was resistance, much of it from Hiroshima and Nagasaki survivors. But there was also a pattern of denial, cover-up and cozy bureaucratic collusion between industry and government, the last especially notorious in Japan but by no means limited to that country. Even then, pro-nuclear power forces could prevail only by managing to instill in the minds of Japanese people a dichotomy between the physics of nuclear power and that of nuclear weapons, an illusory distinction made not only in Japan but throughout the world.
Japan's nuclear industry was not hit as hard by the effects of the Three Mile Island accident (TMI) or the Chernobyl disaster as some other countries. Construction of new plants continued to be strong through the 1980s, 1990s, and up to the present day. However, starting in the mid-1990s there were several nuclear related accidents and cover-ups in Japan that eroded public perception of the industry, resulting in protests and resistance to new plants. These accidents included the Tokaimura nuclear accident, the Mihama steam explosion, cover-ups after an accidents at the Monju reactor, among others, more recently the Chūetsu offshore earthquake aftermath. While exact details may be in dispute, it is clear that the safety culture in Japan's nuclear industry has come under greater scrutiny.
Canceled plant orders include:
• The Maki NPP at Maki, Niigata (Kambara)—Canceled in 2003
• The Kushima NPP at Kushima, Miyazaki—1997
• The Ashihama NPP at Ashihama, Mie—2000
• The Hōhoku NPP at Hōhoku, Yamaguchi—1994
• The Suzu NPP at Suzu, Ishikawa—2003
Note that the Suzu NPP plant proposal is said to be "frozen", meaning that it may continue sometime in the future if economic factors turn more in its favor, though there has been no sign of this happening.
These cancellations reflect to some degree the safety concerns that surfaced after the Monju cover-up (1995) and the Tokaimura accident (1999) and could be compared to the situation in the United States where there was a large number of plant order cancellations after TMI and the Chernobyl disaster. However, it is important to note that most cancellations in Japan are a result of 10, 15, or more years of postponed work and poor support. Through the same time period there were also some new plants connected to the grid, and as of 2007, construction is in progress on several other plants. Japan has thus yet to see a complete break in the construction of new nuclear plants, which has happened in the United States and France.
The Japanese government has maintained strong support for nuclear power. After the Tokaimura accident, many reorganizations of the government funded research organizations occurred and stricter controls were enforced, but the size and scope of research in nuclear power topics has continued to expand. While the number of reactors is expected to increase, the focus of new developments will shift to the advanced fuel cycle and next generation plants. Japan plans to be a major player in the Global Nuclear Energy Partnership and has joined the ITER project. Furthermore, a United States-Japan Joint Nuclear Energy Action Plan has also been created, which is indicative of the commitment the Japanese government has to new nuclear technologies.
In March 2008, Tokyo Electric Power Company announced that the start of operation of four new nuclear power reactors would be postponed by one year due to the incorporation of new earthquake resistance assessments. Units 7 and 8 of the Fukushima Daiichi plant would now enter commercial operation on October 2014 and October 2015, respectively. Unit 1 of the Higashidori plant is now scheduled to begin operating in December 2015, while unit 2 will start up in 2018 at the earliest.
As of September 2008, Japanese ministries and agencies were seeking an increase in the 2009 budget by 6%. The total requested comes to 491.4 billion Japanese yen (4.6 billion USD), and the focuses of research are development of the fast breeder reactor cycle, next-generation light water reactors, the Iter project, and seismic safety.
International cooperation
The nuclear industry in Japan has been highly affected by its U.S. counterpart. Through the late 1990s to present day, the industry has become confident that the United States would see construction of new nuclear plants. Hoping to take advantage of that, along with other opening markets, joint venture agreements between the major nuclear fuel vendors occurred in 1999, 2006, and 2007, following from the legacy of co-operation that began when Japan imported Western technology to jump start its nuclear fleet.
On April 18, 2007, Japan and the United States signed the United States-Japan Joint Nuclear Energy Action Plan, aimed at putting in place a framework for the joint research and development of nuclear energy technology. Each country will conduct research into fast reactor technology, fuel cycle technology, advanced computer simulation and modeling, small and medium reactors, safeguards and physical protection; and nuclear waste management.
In 1954, Japan budgeted 230 million yen for nuclear energy, marking the beginning of the program. The Atomic Energy Basic Law limited activities to only peaceful purposes.
The first nuclear reactor in Japan was built by the UK's GEC. In the 1970s the first Light Water Reactors were built in cooperation with American companies. These plants were bought from U.S. vendors such as General Electric or Westinghouse with contractual work done by Japanese companies, who would later get a license themselves to build similar plant designs. Developments in nuclear power since that time has seen contributions from Japanese companies and research institutes on the same level as the other big users of nuclear power.
Robert Jay Lifton has asked how Japan, after its experience with the atomic bombings of Hiroshima and Nagasaki, could "allow itself to draw so heavily on the same nuclear technology for the manufacture of about a third of its energy". He says:
There was resistance, much of it from Hiroshima and Nagasaki survivors. But there was also a pattern of denial, cover-up and cozy bureaucratic collusion between industry and government, the last especially notorious in Japan but by no means limited to that country. Even then, pro-nuclear power forces could prevail only by managing to instill in the minds of Japanese people a dichotomy between the physics of nuclear power and that of nuclear weapons, an illusory distinction made not only in Japan but throughout the world.
Japan's nuclear industry was not hit as hard by the effects of the Three Mile Island accident (TMI) or the Chernobyl disaster as some other countries. Construction of new plants continued to be strong through the 1980s, 1990s, and up to the present day. However, starting in the mid-1990s there were several nuclear related accidents and cover-ups in Japan that eroded public perception of the industry, resulting in protests and resistance to new plants. These accidents included the Tokaimura nuclear accident, the Mihama steam explosion, cover-ups after an accidents at the Monju reactor, among others, more recently the Chūetsu offshore earthquake aftermath. While exact details may be in dispute, it is clear that the safety culture in Japan's nuclear industry has come under greater scrutiny.
Canceled plant orders include:
• The Maki NPP at Maki, Niigata (Kambara)—Canceled in 2003
• The Kushima NPP at Kushima, Miyazaki—1997
• The Ashihama NPP at Ashihama, Mie—2000
• The Hōhoku NPP at Hōhoku, Yamaguchi—1994
• The Suzu NPP at Suzu, Ishikawa—2003
Note that the Suzu NPP plant proposal is said to be "frozen", meaning that it may continue sometime in the future if economic factors turn more in its favor, though there has been no sign of this happening.
These cancellations reflect to some degree the safety concerns that surfaced after the Monju cover-up (1995) and the Tokaimura accident (1999) and could be compared to the situation in the United States where there was a large number of plant order cancellations after TMI and the Chernobyl disaster. However, it is important to note that most cancellations in Japan are a result of 10, 15, or more years of postponed work and poor support. Through the same time period there were also some new plants connected to the grid, and as of 2007, construction is in progress on several other plants. Japan has thus yet to see a complete break in the construction of new nuclear plants, which has happened in the United States and France.
The Japanese government has maintained strong support for nuclear power. After the Tokaimura accident, many reorganizations of the government funded research organizations occurred and stricter controls were enforced, but the size and scope of research in nuclear power topics has continued to expand. While the number of reactors is expected to increase, the focus of new developments will shift to the advanced fuel cycle and next generation plants. Japan plans to be a major player in the Global Nuclear Energy Partnership and has joined the ITER project. Furthermore, a United States-Japan Joint Nuclear Energy Action Plan has also been created, which is indicative of the commitment the Japanese government has to new nuclear technologies.
In March 2008, Tokyo Electric Power Company announced that the start of operation of four new nuclear power reactors would be postponed by one year due to the incorporation of new earthquake resistance assessments. Units 7 and 8 of the Fukushima Daiichi plant would now enter commercial operation on October 2014 and October 2015, respectively. Unit 1 of the Higashidori plant is now scheduled to begin operating in December 2015, while unit 2 will start up in 2018 at the earliest.
As of September 2008, Japanese ministries and agencies were seeking an increase in the 2009 budget by 6%. The total requested comes to 491.4 billion Japanese yen (4.6 billion USD), and the focuses of research are development of the fast breeder reactor cycle, next-generation light water reactors, the Iter project, and seismic safety.
International cooperation
The nuclear industry in Japan has been highly affected by its U.S. counterpart. Through the late 1990s to present day, the industry has become confident that the United States would see construction of new nuclear plants. Hoping to take advantage of that, along with other opening markets, joint venture agreements between the major nuclear fuel vendors occurred in 1999, 2006, and 2007, following from the legacy of co-operation that began when Japan imported Western technology to jump start its nuclear fleet.
On April 18, 2007, Japan and the United States signed the United States-Japan Joint Nuclear Energy Action Plan, aimed at putting in place a framework for the joint research and development of nuclear energy technology. Each country will conduct research into fast reactor technology, fuel cycle technology, advanced computer simulation and modeling, small and medium reactors, safeguards and physical protection; and nuclear waste management.
NUCLEAR POWER IN JAPAN
Since 1973, nuclear energy has been a national strategic priority in Japan, as the nation is heavily dependent on imported fuel, with fuel imports accounting for 61% of energy production. There has been concern about the ability of Japan's nuclear plants to withstand seismic activity. The Kashiwazaki-Kariwa Nuclear Power Plant was completely shut down for 21 months following an earthquake in 2007.
Following an earthquake, tsunami, and the failure of cooling systems at the Fukushima I Nuclear Power Plant on March 11, 2011, a nuclear emergency was declared. This was the first time a nuclear emergency had been declared in Japan, and 140,000 residents within 20 km of the plant were evacuated. The amount of radiation released is unclear, as the crisis is ongoing
On 6 May 2011, Prime Minister Naoto Kan ordered the Hamaoka Nuclear Power Plant be shut down as an earthquake of magnitude 8.0 or higher is likely to hit the area within the next 30 years. Kan wanted to avoid a possible repeat of the Fukushima disaster.
Nuclear power plants
There are 55 operating nuclear reactors in Japan with a number of others in construction or being planned. For a list, see List of nuclear reactors or List of power stations in Japan. Following the Fukushima I nuclear accidents Prime Minister Naoto Kan has announced that all 6 of the reactors at the Fukushima I Nuclear Power Plant will be decommissioned. The plant operators had previously stated that reactors 1 to 4 would never operate again.
Nuclear accidents
In terms of consequences of radiation release, worker exposure, and core damage the Fukushima I nuclear accidents in 2011 were the worst experienced by the industry in addition to ranking among the worst civilian nuclear accidents. The Tokaimura reprocessing plant fire in 1999 has 2 worker deaths, one more exposed to radiation levels above legal limits and over 660 others received detectable radiation doses but below permissible levels. The Mihama Nuclear Power Plant experienced a steam explosion in one of the turbine buildings in 2004 where 4 workers were killed and seven others injured.
2011 accidents
A map showing epicenter of earthquake and position of nuclear power plantsMain article: 2011 Japanese nuclear accidents
There have been many nuclear shutdowns, failures, and partial meltdowns which were triggered by the 2011 Tōhoku earthquake and tsunami.
Plant description Accident descriptions
Fukushima I Nuclear Power Plant Fukushima I nuclear accidents
Timeline of the Fukushima nuclear accidents
Fukushima II Nuclear Power Plant Fukushima II nuclear accidents
Onagawa Nuclear Power Plant Onagawa Nuclear Power Plant incidents
Tōkai Nuclear Power Plant Tōkai Nuclear Power Plant incidents
Rokkasho Reprocessing Plant Rokkasho Reprocessing Plant incidents
Fukushima 1 accidentsAccording to the Federation of Electric Power Companies of Japan, "by April 27 approximately 55 percent of the fuel in reactor unit 1 had melted, along with 35 percent of the fuel in unit 2, and 30 percent of the fuel in unit 3; and overheated spent fuels in the storage pools of units 3 and 4 probably were also damaged". The accident has surpassed the 1979 Three Mile Island accident in seriousness, and is comparable to the 1986 Chernobyl disaster.The Economist reports that the Fukushima disaster is "a bit like three Three Mile Islands in a row, with added damage in the spent-fuel stores", and that there will be ongoing impacts:
Years of clean-up will drag into decades.
A permanent exclusion zone could end up stretching beyond the plant’s perimeter. Seriously exposed workers may be at increased risk of cancers for the rest of their lives...
On March 24, 2011, Japanese officials announced that "radioactive iodine-131 exceeding safety limits for infants had been detected at 18 water-purification plants in Tokyo and five other prefectures". Officials said also that the fallout from the Dai-ichi plant is "hindering search efforts for victims from the March 11 earthquake and tsunami".
Other accidentsMain article: Nuclear accidents by country
See also: Lists of nuclear disasters and radioactive incidents
Other accidents of note include:
1981: almost 300 workers were exposed to excessive levels of radiation after a fuel rod ruptured during repairs at the Tsuruga Nuclear Power Plant.
December 1995: the fast breeder Monju Nuclear Power Plant sodium leak. State-run operator Donen was found to have concealed videotape footage that showed extensive damage to the reactor.
March 1997: the Tokaimura nuclear reprocessing plant fire and explosion, northeast of Tokyo. 37 workers were exposed to low doses of radiation. Donen later acknowledged it had initially suppressed information about the fire.
1999: a fuel loading system malfunctioned at a nuclear plant in the Fukui Prefecture and set off an uncontrolled nuclear reaction and explosion.
September 1999: the criticality accident at the Tokai fuel fabrication facility. Hundreds of people were exposed to radiation, three workers received doses above legal limits of whom two later died.
2000: Three Tokyo Electric Power Co. executives were forced to quit after the company in 1989 ordered an employee to edit out footage showing cracks in nuclear plant steam pipes in video being submitted to regulators.
August 2002: a widespread falsification scandal starting in that led to the shut down of all Tokyo Electric Power Company’s 17 nuclear reactors; Tokyo Electric's officials had falsified inspection records and attempted to hide cracks in reactor vessel shrouds in 13 of its 17 units.
2002: Two workers were exposed to a small amount of radiation and suffered minor burns during a fire at Onagawa Nuclear Power Station in northern Japan.
9 August 2004: four workers were killed after a steam explosion at the Mihama-3 station; the subsequent investigation revealed a serious lack in systematic inspection in Japanese nuclear plants, which led to a massive inspection program.
2006: A small amount of radioactive steam was released at the Fukushima Dai-ichi plant and it escaped the compound.
16 July 2007: a severe earthquake (measuring 6.8 on the Richter scale) hit the region where Tokyo Electric's Kashiwazaki-Kariwa Nuclear Power Plant is located and radioactive water spilled into the Sea of Japan; as of March 2009, all of the reactors remain shut down for damage verification and repairs; the plant with seven units was the largest single nuclear power station in the world.
Following an earthquake, tsunami, and the failure of cooling systems at the Fukushima I Nuclear Power Plant on March 11, 2011, a nuclear emergency was declared. This was the first time a nuclear emergency had been declared in Japan, and 140,000 residents within 20 km of the plant were evacuated. The amount of radiation released is unclear, as the crisis is ongoing
On 6 May 2011, Prime Minister Naoto Kan ordered the Hamaoka Nuclear Power Plant be shut down as an earthquake of magnitude 8.0 or higher is likely to hit the area within the next 30 years. Kan wanted to avoid a possible repeat of the Fukushima disaster.
Nuclear power plants
There are 55 operating nuclear reactors in Japan with a number of others in construction or being planned. For a list, see List of nuclear reactors or List of power stations in Japan. Following the Fukushima I nuclear accidents Prime Minister Naoto Kan has announced that all 6 of the reactors at the Fukushima I Nuclear Power Plant will be decommissioned. The plant operators had previously stated that reactors 1 to 4 would never operate again.
Nuclear accidents
In terms of consequences of radiation release, worker exposure, and core damage the Fukushima I nuclear accidents in 2011 were the worst experienced by the industry in addition to ranking among the worst civilian nuclear accidents. The Tokaimura reprocessing plant fire in 1999 has 2 worker deaths, one more exposed to radiation levels above legal limits and over 660 others received detectable radiation doses but below permissible levels. The Mihama Nuclear Power Plant experienced a steam explosion in one of the turbine buildings in 2004 where 4 workers were killed and seven others injured.
2011 accidents
A map showing epicenter of earthquake and position of nuclear power plantsMain article: 2011 Japanese nuclear accidents
There have been many nuclear shutdowns, failures, and partial meltdowns which were triggered by the 2011 Tōhoku earthquake and tsunami.
Plant description Accident descriptions
Fukushima I Nuclear Power Plant Fukushima I nuclear accidents
Timeline of the Fukushima nuclear accidents
Fukushima II Nuclear Power Plant Fukushima II nuclear accidents
Onagawa Nuclear Power Plant Onagawa Nuclear Power Plant incidents
Tōkai Nuclear Power Plant Tōkai Nuclear Power Plant incidents
Rokkasho Reprocessing Plant Rokkasho Reprocessing Plant incidents
Fukushima 1 accidentsAccording to the Federation of Electric Power Companies of Japan, "by April 27 approximately 55 percent of the fuel in reactor unit 1 had melted, along with 35 percent of the fuel in unit 2, and 30 percent of the fuel in unit 3; and overheated spent fuels in the storage pools of units 3 and 4 probably were also damaged". The accident has surpassed the 1979 Three Mile Island accident in seriousness, and is comparable to the 1986 Chernobyl disaster.The Economist reports that the Fukushima disaster is "a bit like three Three Mile Islands in a row, with added damage in the spent-fuel stores", and that there will be ongoing impacts:
Years of clean-up will drag into decades.
A permanent exclusion zone could end up stretching beyond the plant’s perimeter. Seriously exposed workers may be at increased risk of cancers for the rest of their lives...
On March 24, 2011, Japanese officials announced that "radioactive iodine-131 exceeding safety limits for infants had been detected at 18 water-purification plants in Tokyo and five other prefectures". Officials said also that the fallout from the Dai-ichi plant is "hindering search efforts for victims from the March 11 earthquake and tsunami".
Other accidentsMain article: Nuclear accidents by country
See also: Lists of nuclear disasters and radioactive incidents
Other accidents of note include:
1981: almost 300 workers were exposed to excessive levels of radiation after a fuel rod ruptured during repairs at the Tsuruga Nuclear Power Plant.
December 1995: the fast breeder Monju Nuclear Power Plant sodium leak. State-run operator Donen was found to have concealed videotape footage that showed extensive damage to the reactor.
March 1997: the Tokaimura nuclear reprocessing plant fire and explosion, northeast of Tokyo. 37 workers were exposed to low doses of radiation. Donen later acknowledged it had initially suppressed information about the fire.
1999: a fuel loading system malfunctioned at a nuclear plant in the Fukui Prefecture and set off an uncontrolled nuclear reaction and explosion.
September 1999: the criticality accident at the Tokai fuel fabrication facility. Hundreds of people were exposed to radiation, three workers received doses above legal limits of whom two later died.
2000: Three Tokyo Electric Power Co. executives were forced to quit after the company in 1989 ordered an employee to edit out footage showing cracks in nuclear plant steam pipes in video being submitted to regulators.
August 2002: a widespread falsification scandal starting in that led to the shut down of all Tokyo Electric Power Company’s 17 nuclear reactors; Tokyo Electric's officials had falsified inspection records and attempted to hide cracks in reactor vessel shrouds in 13 of its 17 units.
2002: Two workers were exposed to a small amount of radiation and suffered minor burns during a fire at Onagawa Nuclear Power Station in northern Japan.
9 August 2004: four workers were killed after a steam explosion at the Mihama-3 station; the subsequent investigation revealed a serious lack in systematic inspection in Japanese nuclear plants, which led to a massive inspection program.
2006: A small amount of radioactive steam was released at the Fukushima Dai-ichi plant and it escaped the compound.
16 July 2007: a severe earthquake (measuring 6.8 on the Richter scale) hit the region where Tokyo Electric's Kashiwazaki-Kariwa Nuclear Power Plant is located and radioactive water spilled into the Sea of Japan; as of March 2009, all of the reactors remain shut down for damage verification and repairs; the plant with seven units was the largest single nuclear power station in the world.
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