搜尋結果
The Chernobyl disaster [a] began on 26 April 1986 with the explosion of the No. 4 reactor of the Chernobyl Nuclear Power Plant near the city of Pripyat in the north of the Ukrainian SSR, close to the border with the Byelorussian SSR, in the Soviet Union. [1] It is one of only two nuclear energy accidents rated at seven—the maximum severity ...
- Reactor design and operator error
- INES Level 7 (major accident)
- 26 April 1986; 37 years ago
The Tiananmen Square protests, known in China as the June Fourth Incident, [1] [2] [a] were student-led demonstrations held in Tiananmen Square, Beijing, China, lasting from 15 April to 4 June 1989. After weeks of unsuccessful attempts between the demonstrators and the Chinese government to find a peaceful resolution, the Chinese government ...
- 15 April – 4 June 1989, (1 month, 2 weeks and 6 days)
- See Death toll
- Causes
- Light-Water Reactors
- Other Reactor Types
- Soviet Union–Designed Reactors
- Effects
- Reactor Design
- China Syndrome
- See Also
- External Links
Nuclear power plants generate electricity by heating fluid via a nuclear reaction to run a generator. If the heat from that reaction is not removed adequately, the fuel assemblies in a reactor core can melt. A core damage incident can occur even after a reactor is shut down because the fuel continues to produce decay heat. A core damage accident is...
Before the core of a light-water nuclear reactorcan be damaged, two precursor events must have already occurred: 1. A limiting fault (or a set of compounded emergency conditions) that leads to the failure of heat removal within the core (the loss of cooling). Low water level uncovers the core, allowing it to heat up. 2. Failure of the emergency cor...
Other types of reactors have different capabilities and safety profiles than the LWR does. Advanced varieties of several of these reactors have the potential to be inherently safe.
RBMKs
Soviet-designed RBMK reactors (Reaktor Bolshoy Moshchnosti Kanalnyy), found only in Russia and other post-Soviet states and now shut down everywhere except Russia, do not have containment buildings, are naturally unstable (tending to dangerous power fluctuations), and have emergency cooling systems (ECCS) considered grossly inadequate by Western safety standards. The reactor involved in the Chernobyl disasterwas an RBMK. RBMK emergency core cooling systems only have one division and little re...
MKER
The MKERis a modern Russian-engineered channel type reactor that is a distant descendant of the RBMK, designed to optimize the benefits and fix the serious flaws of the original. Several unique features of the MKER's design make it a credible and interesting option. The reactor remains online during refueling, ensuring outages only occasionally for maintenance, with uptime up to 97-99%. The moderator design allows the use of less-enriched fuels, with a high burnup rate. Neutronics characteris...
VVER
The VVERis a pressurized light-water reactor that is far more stable and safe than the RBMK. This is because it uses light water as a moderator (rather than graphite), has well-understood operating characteristics, and has a negative void coefficient of reactivity. In addition, some have been built with more than marginal containments, some have quality ECCS systems, and some have been upgraded to international standards of control and instrumentation. Present generations of VVERs (starting f...
The effects of a nuclear meltdown depend on the safety features designed into a reactor. A modern reactor is designed both to make a meltdown unlikely, and to contain one should it occur. In a modern reactor, a nuclear meltdown, whether partial or total, should be contained inside the reactor's containment structure. Thus (assuming that no other ma...
Although pressurized water reactors are more susceptible to nuclear meltdown in the absence of active safety measures, this is not a universal feature of civilian nuclear reactors. Much of the research in civilian nuclear reactors is for designs with passive nuclear safety features that may be less susceptible to meltdown, even if all emergency sys...
The China syndrome (loss-of-coolant accident) is a nuclear reactor operations accident characterized by the severe meltdown of the core components of the reactor, which then burn through the containment vessel and the housing building, then (figuratively) through the crust and body of the Earth until reaching the opposite end, presumed to be in "Ch...
Annotated bibliography on civilian nuclear accidents from the Alsos Digital Library for Nuclear IssuesViviparus georgianus, commonly known as the banded mystery snail, is a species of large freshwater snail in the family Viviparidae, the river snails. It is native to North America, generally found from the northeastern United States to Florida and the Gulf of Mexico, and thrives in eutrophic lentic environments such as lakes, ponds and some low ...
A convoy of fire engines in the tsunami zone. The aftermath of the 2011 Tōhoku earthquake and tsunami included both a humanitarian crisis and massive economic impacts. The tsunami created over 300,000 refugees in the Tōhoku region of Japan, and resulted in shortages of food, water, shelter, medicine and fuel for survivors. 15,900 deaths have ...
e. The Union of Soviet Socialist Republics (USSR) was dissolved on 26 December 1991 by Declaration № 142-Н of the Soviet of the Republics of the Supreme Soviet of the Soviet Union, formally establishing the dissolution of the Soviet Union as a sovereign state and subject of international law. [1] It also brought an end to the Soviet Union's ...
What links here Related changes Upload file Special pages Permanent link Page information Cite this page Get shortened URL Download QR code The region today: Israel, the West Bank, the Gaza Strip and the Golan Heights The history of the Israeli–Palestinian conflict traces back to the late 19th century when Zionists sought to establish a homeland for the Jewish people in Ottoman-controlled ...
