www.isramart.com
The discovery of radioactive gas known to be the by-product of nuclear fission at the Fukushima nuclear plant could delay efforts to shut down its crippled reactors safely.
Operator Tepco announced this morning that low densities of xenon-133 and xenon-135 had been detected in gas samples taken from Reactor 2, one of the three at the Japanese plant to melt down following the tsunami and earthquake in March.
Both substances have half-lives of around five days and nine hours, respectively, which indicates nuclear fission activity could still be taking place in the damaged core, previously thought to be near a stable shutdown.
"Given the signs, it is certain that fission is occurring," Junichi Matsumoto, a general manager at Tepco, told reporters.
Tepco said there has been no increase in temperature or pressure in the core or radiation levels outside it, and dismissed the potential for a "major criticality accident". Japan's nuclear safety agency also said the situation was stable and the small amounts of material present would not put public health at risk.
While the company has not ruled out a false reading, workers are now pumping boric acid into the reactor to suppress fission.
Tepco spokesman Osamu Yokokura told Associated Press the incident would not derail plans to make the entire plant sage by the end of the year.
He said: "We have confirmed the reactor is stable and don't believe this will have any impact on our future work."
Decommissioning the plant may take up to 30 years, while nearby residents have been warned the areas closest to the plant could remain dangerous for even longer.
In October, Tepco said the level of radiation being emitted from the complex had halved from the previous month.
The discovery of radioactive gas known to be the by-product of nuclear fission at the Fukushima nuclear plant could delay efforts to shut down its crippled reactors safely.
Operator Tepco announced this morning that low densities of xenon-133 and xenon-135 had been detected in gas samples taken from Reactor 2, one of the three at the Japanese plant to melt down following the tsunami and earthquake in March.
Both substances have half-lives of around five days and nine hours, respectively, which indicates nuclear fission activity could still be taking place in the damaged core, previously thought to be near a stable shutdown.
"Given the signs, it is certain that fission is occurring," Junichi Matsumoto, a general manager at Tepco, told reporters.
Tepco said there has been no increase in temperature or pressure in the core or radiation levels outside it, and dismissed the potential for a "major criticality accident". Japan's nuclear safety agency also said the situation was stable and the small amounts of material present would not put public health at risk.
While the company has not ruled out a false reading, workers are now pumping boric acid into the reactor to suppress fission.
Tepco spokesman Osamu Yokokura told Associated Press the incident would not derail plans to make the entire plant sage by the end of the year.
He said: "We have confirmed the reactor is stable and don't believe this will have any impact on our future work."
Decommissioning the plant may take up to 30 years, while nearby residents have been warned the areas closest to the plant could remain dangerous for even longer.
In October, Tepco said the level of radiation being emitted from the complex had halved from the previous month.
Posts
