Record radiation level detected inside damaged Fukushima reactor
– Japan Today
An official of the National Institute of Radiological Sciences said medical professionals have never considered dealing with this level of radiation in their work
A record radiation level has been detected inside the No. 2 reactor at the damaged Fukushima Daiichi nuclear complex, with the estimated reading of up to 530 sieverts per hour, the plant operator said Thursday.
The reading means a person could die from even brief exposure, highlighting the difficulties ahead as the government and Tokyo Electric Power Company Holdings Inc. grope their way toward dismantling all three reactors that melted down in the March 2011 nuclear disaster.
The plant operator also announced that based on an image analysis, a 1-square-meter hole has been found on a metal grating beneath the reactor pressure vessel, likely caused by melted nuclear fuel that fell through the vessel.
The new radiation level, described by some experts as “unimaginable,” far exceeds 73 sieverts per hour, the previously highest radiation reading monitored in the interior of the reactor.
An official of the National Institute of Radiological Sciences said medical professionals have never considered dealing with this level of radiation in their work.
According to TEPCO, the extremely high radiation level was detected inside the containment vessel, in the space around 2.3 meters away from the base of the reactor pressure vessel.
According to the institute, 4 sieverts of radiation exposure would kill one in two people.
Experts say 1,000 millisieverts, which equals 1 sievert, could lead to infertility, loss of hair and cataracts, while exposure to radiation doses above 100 millisieverts increases the risk of cancer.
The latest discovery spells difficulty in removing the fuel debris as part of decommissioning work at the plant. The government and TEPCO hope to locate the fuel and start removing it from a first reactor in 2021.
The debris is believed to have been created as nuclear fuel inside the reactor pressure vessel overheated and melted due to the loss of reactor cooling functions.”
…..Continue reading @ Japan Today
Radiation Levels Are Soaring Inside the Damaged Fukushima Nuclear Plant
“Radiation levels inside a damaged reactor at Japan’s Fukushima nuclear plant have hit a record high, and are the worst since the plant suffered a triple meltdown nearly six years ago. The latest readings now pose a serious challenge as officials prepare to dismantle the stricken facility.
Radiation levels inside the containment vessel of reactor No. 2 at Fukushima has reached 530 sieverts per hour—a figure described by experts as “unimaginable.” The readings, taken by Tokyo Electric Power Co. Holdings Inc. (Tepco), were taken near the entrance of a space immediately below the pressure vessel, which contains the reactor core.
The radiation level inside the plant now far exceeds the previous high of 73 sieverts per hour, which was recorded soon after the triple meltdown in March 2011. Tepco made the readings by analyzing electronic noise caused by the radiation in video images. The company says this technique has a margin of error of plus or minus 30 percent (so even at the extreme low ball, the levels are no lower than 370 sieverts per minute—but possibly as high as 690!).
These surging radiation levels are complicating plans to dismantle the plant.
According to the National Institute of Radiological Sciences, medical professionals aren’t prepared to treat patients who have been exposed to the levels of radiation currently experienced at the facility. This is a big problem for Tepco, which plans to remove fuel debris as part of the decommissioning process. The dismantling of Fukushima is scheduled to start in 2021 and could take nearly a half-century.
Officials with Tepco aren’t entirely sure why radiation levels are on such a dramatic upward trend. Either previous readings were insufficient or incorrect, or conditions inside the plant are changing. Problem is, the interior condition of the plant is still a big mystery. The high readings suggest that some of the melted fuel that escaped the pressure vessel is lingering nearby. Should this be confirmed, it would mark the first time that tainted debris has been found in any of the three reactors that suffered core meltdowns. Tepco has been unable to confirm the condition of the melted fuel owing to the extreme and inhospitable conditions inside.”
….Continue reading more @ Gizmodo
Highest radiation reading since 3/11 detected at Fukushima No. 1 reactor
– Japan Times
“The radiation level in the containment vessel of reactor 2 at the crippled Fukushima No. 1 power plant has reached a maximum of 530 sieverts per hour, the highest since the triple core meltdown in March 2011, Tokyo Electric Power Co. Holdings Inc. said.
Tepco said on Thursday that the blazing radiation reading was taken near the entrance to the space just below the pressure vessel, which contains the reactor core.
The high figure indicates that some of the melted fuel that escaped the pressure vessel is nearby.
At 530 sieverts, a person could die from even brief exposure, highlighting the difficulties ahead as the government and Tepco grope their way toward dismantling all three reactors crippled by the March 2011 disaster.
Tepco also announced that, based on its analysis of images taken by a remote-controlled camera, that there is a 2-meter hole in the metal grating under the pressure vessel in the reactor’s primary containment vessel. It also thinks part of the grating is warped.
The hole could have been caused when the fuel escaped the pressure vessel after the mega-quake and massive tsunami triggered a station blackout that crippled the plant’s ability to cool the reactors.
The searing radiation level, described by some experts as “unimaginable,” far exceeds the previous high of 73 sieverts per hour at the reactor.”
….Contine reading more @ Japan Times