http://cnews.canoe.ca/CNEWS/World/2011/11/02/18913236.html
“But it is worth noting that even if the fuel is cooled, there is still a small amount of residual natural fission of the large amount of uranium fuel in the core. ...As with other reports, this one does not appear to show any new radiological hazard from the disaster.”
Tepco, which was widely criticized for its slow release of information in the early days of the disaster, said it was still assessing the find but that it believes any criticality was temporary and finished.
The amount of detected xenon was small and the nuclear fuel in the No 2 reactor was unlikely to have melted down again, Tepco said.
The fuel rods in the No 2 reactor and two other reactors melted down early in the crisis after the tsunami knocked out the plant’s cooling system.
“We think there won’t be an impact on the surrounding environment even if criticality did take place, given that there is no change to parameters from the plant,” said an official at the Nuclear Industrial Safety Agency, Japan’s nuclear watchdog.
“The amount of detected xenon is so low to have an effect, although we are still in the process of fully analysing the situation,” he said.
Tepco said the temperature and pressure at the No 2 reactor remained stable.
The company has succeeded in bringing down the temperatures at the three damaged reactors from levels considered dangerous and hopes to declare a cold shutdown — when temperatures are stable below boiling point — this year.
Tepco said in October that the amount of radiation being emitted from the complex had halved from a month earlier in the latest sign that efforts to bring the facility under control are progressing.
