l**t
发帖数: 6971 | 1 http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
Possible Nuclear Fission Detected at Fukushima Plant
Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
Fukushima atomic power plant in northern Japan, raising the risk of more
radiation leaks. The situation is under control, officials said.
The company, known as Tepco, began spraying boric acid on the No. 2 reactor
at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
may have found xenon, which is associated with nuclear fission, while
examining gases taken from the reactor, according to an e-mailed statement
today.
“Given the signs, it’s certain that fission is occurring,” Junichi
Matsumoto, a general manager at Tepco who regularly talks to the media, told
reporters in Tokyo today. There’s been no large-scale or sustained
criticality, he said.
The discovery of an atomic reaction that can produce a nuclear explosion
comes amid rising concerns about possible contamination after another
radioactive hot spot was discovered in Tokyo on Oct. 29. It’s possible
there are similar reactions occurring in the No. 1 and No. 3 reactors, the
other cores damaged at the station, Matsumoto said.
“Melted fuel in the No. 2 reactor may have undergone a sustained process of
nuclear fission or re-criticality,” Tetsuo Ito, the head of Kinki
University’s Atomic Energy Research Institute, said by phone. “The nuclear
fission should be containable by injecting boron into the reactor to absorb
neutrons.”
Loss of Cooling
Shares of Tepco declined as much as 6.8 percent, the biggest intraday loss
since Oct. 21, and traded 1 percent lower at 307 yen at 12:58 p.m. on the
Tokyo Stock Exchange. The benchmark Nikkei 225 Stock Average was down 1.6
percent.
Eight months after the March 11 earthquake and tsunami wrecked the Fukushima
Dai-Ichi plant, causing a loss of cooling and the meltdowns of three
reactors, Tepco is trying to prevent leakage of radiation that has spread
across the world.
The incident, the worst atomic disaster since Chernobyl in 1986, was
responsible for the biggest discharge of radioactive material into the ocean
in history, according to a study from a French nuclear safety institute.
“We are evaluating whether there are many reactions or not or whether its
stopped, Matsumoto said. The incident won’t affect its schedule of bringing
the plant under control by the end of this year, Matsumoto said.
Yasuhiro Sonoda, a member of the ruling Democratic Party of Japan, on Oct.
31 drank a glass of filtered water from the Fukushima plant to demonstrate
the situation is being brought under control.
Publicity Stunt
Sonoda denied reporters’ claims it was a publicity stunt. ‘‘I drank it
because there shouldn’t be any concerns about the water,” he said. “I
didn’t intend to say it’s completely safe by drinking it.”
No significant changes in temperatures and pressures of the reactor and
radiation levels at the site have been detected, said Hiroyuki Usami, a
spokesman for Tepco.
Should fissioning have occurred the injection of boron will have stopped it,
said Tadashi Narabayashi, a former reactor safety researcher at Toshiba
Corp. (6502) and now a nuclear engineering professor at Hokkaido University.
Fissioning involves the splitting of atoms, which, in the case of certain
uranium isotopes, can lead to an uncontrolled reaction.
Tepco and the government have said they are on track to bring the damaged
reactors into a safe state known as cold shutdown by the end of the year.
The company has been mixing boron with cooling water in the reactors to
prevent accidental chain reactions.
Core Meltdowns
Tepco and the Japan Atomic Energy Agency are reexamining the gases, said
Toshiyuki Koganeya, a spokesman for the Nuclear and Industrial Safety Agency
, the government regulator.
Even if Tepco’s analysis is correct, nuclear fission would be taking place
in a “very restricted part” of the reactor, said Koganeya. The regulator
believes fuel accumulated at the bottom of the pressure vessel and
containment vessel is unlikely to start melting again, he said.
Fukushima has sustained major damage at four of its six reactor buildings at
the Dai-Ichi plant, including the three core meltdowns and possible damage
to a spent fuel pool.
The radioactive cesium that flowed into the sea from the plant was 20 times
the amount estimated by Tepco, according to the Institute for Radiological
Protection and Nuclear Safety, which is funded by the French government.
The oceanic study estimates 27,000 terabecquerels of radioactive cesium 137
leaked into the sea from the plant.
To contact the reporters on this story: Tsuyoshi Inajima in Tokyo at
t******[email protected]; Yuji Okada in Tokyo at y*****[email protected]
To contact the editor responsible for this story: Teo Chian Wei at cwteo@
bloomberg.net | a******o
发帖数: 16625 | 2 小日本国运不济了。
reactor
it
【在 l**t 的大作中提到】
: http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
: Possible Nuclear Fission Detected at Fukushima Plant
: Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
: Fukushima atomic power plant in northern Japan, raising the risk of more
: radiation leaks. The situation is under control, officials said.
: The company, known as Tepco, began spraying boric acid on the No. 2 reactor
: at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
: may have found xenon, which is associated with nuclear fission, while
: examining gases taken from the reactor, according to an e-mailed statement
: today.
| l**t
发帖数: 6971 | 3 http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
Possible Nuclear Fission Detected at Fukushima Plant
Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
Fukushima atomic power plant in northern Japan, raising the risk of more
radiation leaks. The situation is under control, officials said.
The company, known as Tepco, began spraying boric acid on the No. 2 reactor
at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
may have found xenon, which is associated with nuclear fission, while
examining gases taken from the reactor, according to an e-mailed statement
today.
“Given the signs, it’s certain that fission is occurring,” Junichi
Matsumoto, a general manager at Tepco who regularly talks to the media, told
reporters in Tokyo today. There’s been no large-scale or sustained
criticality, he said.
The discovery of an atomic reaction that can produce a nuclear explosion
comes amid rising concerns about possible contamination after another
radioactive hot spot was discovered in Tokyo on Oct. 29. It’s possible
there are similar reactions occurring in the No. 1 and No. 3 reactors, the
other cores damaged at the station, Matsumoto said.
“Melted fuel in the No. 2 reactor may have undergone a sustained process of
nuclear fission or re-criticality,” Tetsuo Ito, the head of Kinki
University’s Atomic Energy Research Institute, said by phone. “The nuclear
fission should be containable by injecting boron into the reactor to absorb
neutrons.”
Loss of Cooling
Shares of Tepco declined as much as 6.8 percent, the biggest intraday loss
since Oct. 21, and traded 1 percent lower at 307 yen at 12:58 p.m. on the
Tokyo Stock Exchange. The benchmark Nikkei 225 Stock Average was down 1.6
percent.
Eight months after the March 11 earthquake and tsunami wrecked the Fukushima
Dai-Ichi plant, causing a loss of cooling and the meltdowns of three
reactors, Tepco is trying to prevent leakage of radiation that has spread
across the world.
The incident, the worst atomic disaster since Chernobyl in 1986, was
responsible for the biggest discharge of radioactive material into the ocean
in history, according to a study from a French nuclear safety institute.
“We are evaluating whether there are many reactions or not or whether its
stopped, Matsumoto said. The incident won’t affect its schedule of bringing
the plant under control by the end of this year, Matsumoto said.
Yasuhiro Sonoda, a member of the ruling Democratic Party of Japan, on Oct.
31 drank a glass of filtered water from the Fukushima plant to demonstrate
the situation is being brought under control.
Publicity Stunt
Sonoda denied reporters’ claims it was a publicity stunt. ‘‘I drank it
because there shouldn’t be any concerns about the water,” he said. “I
didn’t intend to say it’s completely safe by drinking it.”
No significant changes in temperatures and pressures of the reactor and
radiation levels at the site have been detected, said Hiroyuki Usami, a
spokesman for Tepco.
Should fissioning have occurred the injection of boron will have stopped it,
said Tadashi Narabayashi, a former reactor safety researcher at Toshiba
Corp. (6502) and now a nuclear engineering professor at Hokkaido University.
Fissioning involves the splitting of atoms, which, in the case of certain
uranium isotopes, can lead to an uncontrolled reaction.
Tepco and the government have said they are on track to bring the damaged
reactors into a safe state known as cold shutdown by the end of the year.
The company has been mixing boron with cooling water in the reactors to
prevent accidental chain reactions.
Core Meltdowns
Tepco and the Japan Atomic Energy Agency are reexamining the gases, said
Toshiyuki Koganeya, a spokesman for the Nuclear and Industrial Safety Agency
, the government regulator.
Even if Tepco’s analysis is correct, nuclear fission would be taking place
in a “very restricted part” of the reactor, said Koganeya. The regulator
believes fuel accumulated at the bottom of the pressure vessel and
containment vessel is unlikely to start melting again, he said.
Fukushima has sustained major damage at four of its six reactor buildings at
the Dai-Ichi plant, including the three core meltdowns and possible damage
to a spent fuel pool.
The radioactive cesium that flowed into the sea from the plant was 20 times
the amount estimated by Tepco, according to the Institute for Radiological
Protection and Nuclear Safety, which is funded by the French government.
The oceanic study estimates 27,000 terabecquerels of radioactive cesium 137
leaked into the sea from the plant.
To contact the reporters on this story: Tsuyoshi Inajima in Tokyo at
t******[email protected]; Yuji Okada in Tokyo at y*****[email protected]
To contact the editor responsible for this story: Teo Chian Wei at cwteo@
bloomberg.net | a******o
发帖数: 16625 | 4 小日本国运不济了。
reactor
it
【在 l**t 的大作中提到】
: http://www.bloomberg.com/news/2011-11-01/tepco-says-nuclear-fis
: Possible Nuclear Fission Detected at Fukushima Plant
: Tokyo Electric Power Co. detected signs of nuclear fission at its crippled
: Fukushima atomic power plant in northern Japan, raising the risk of more
: radiation leaks. The situation is under control, officials said.
: The company, known as Tepco, began spraying boric acid on the No. 2 reactor
: at 2:48 a.m. Japan time to prevent accidental chain reactions. Tepco said it
: may have found xenon, which is associated with nuclear fission, while
: examining gases taken from the reactor, according to an e-mailed statement
: today.
| z********e
发帖数: 8818 | |
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