The level of water inside reactor 1 at the Fukushima No. 1 nuclear plant may be alarmingly lower than Tepco’s current estimates, the Japan Nuclear Energy Safety Organization has calculated.
Tokyo Electric Power Co. claims the water level in the primary containment vessel is about 1.9 meters deep, but the organization’s nuclear experts said Tuesday it may actually be as low as 40 cm, increasing the risk that melted fuel may be exposed.
The organization, under the industry ministry, believes the water may be leaking from a 2 cm hole in a section of the reactor connecting the primary container and the suppression pool.
However, they conceded there are “uncertainties” in the analysis and also did not dispute that coolant water being injected into the crippled reactor is leaking.
Also Tuesday, Tepco spokesman Junichi Matsumoto said the utility hopes to insert an endoscope into the unit by year’s end to determine the precise water depth, but declined comment on the analysis. When Tepco inserted an endoscope into the crippled No. 2 reactor, it found a lower-than-expected 60-cm level.
Matsumoto would only say that the reactor’s nuclear fuel remains submerged and at a cool temperature. “We believe that the fuel is being cooled,” he said, referring to temperature readings.
The analysis was based on the assumption that the primary container is filled with steam created by coolant water being pumped in to cool the fuel rods, and nitrogen injections to prevent hydrogen explosions. The calculations assumed that the coolant water is leaking from the container’s lower part and gas from the upper part.
Oi towns oppose restart
Only two of the 11 municipalities within a 30-km radius of the Oi nuclear plant in Fukui Prefecture are in favor of restarting two idled reactors at the facility, according to a recent poll.
While Prime Minister Yoshihiko Noda is expected to soon make a final decision on whether to restart the two Kansai Electric Power Co. reactor units, the poll by Kyodo News indicates he has failed to make any headway in persuading the municipalities affected to grant consent.
Of the 11 local governments polled, only the towns of Takahama and Mihama, which host other nuclear plants run by Kepco, supported putting the Oi reactors back online — on condition that the prefecture and the town of Oi give prior approval.