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Contaminated water leak found at Ehime Pref. nuke plant

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In this file photo, the No. 3 reactor, center left, of Shikoku Electric Power Co. Ikata Nuclear Power Station is seen from a Mainichi Shimbun helicopter on March 28, 2017.
IKATA, Ehime — Water containing radioactive materials has leaked from a purification system inside of a stalled nuclear reactor here, Shikoku Electric Power Co. and the Ehime Prefectural Government announced on May 9.
The leak occurred in the auxiliary building of the No. 3 reactor at the Ikata Nuclear Power Station in the town of Ikata, Ehime Prefecture. According to the prefectural government and Shikoku Electric, the coolant water was found to be leaking from the pressure gauge stop valve for the purification system at around 2:10 a.m. on May 9.
The radiation level of the materials in the roughly 130 milliliters of escaped water measured 20 becquerels, far below the standard for filing a report to the central government. The utility and Ehime Prefecture said there is no reported leakage outside of the facility, nor was there any danger posed to employees or the surrounding environment. Regardless, the reason for the leak will be investigated thoroughly.
The No. 3 Reactor at the facility was restarted in August 2016. However, while the rector was undergoing a scheduled inspection in December 2017, a temporary injunction was handed down by the Hiroshima High Court that halted operation at the site.
(Japanese original by Aoi Hanazawa, Matsuyama Bureau)

 

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May 10, 2018 Posted by | Japan | , , | Leave a comment

Ohi No.4 reactor restarted

Japan’s 8th reactor is back online. Kansai Electric Power Company on Wednesday restarted a reactor at the Ohi plant in Fukui Prefecture, central Japan.
 
At the plant, workers pulled out the control rods that suppress atomic fission of the No.4 reactor.
 
The facility is expected to reach criticality early Thursday, begin power generation and transmission on Friday and go into commercial operation in early June.
 
The reactor had complied with new government regulations put in place following the 2011 Fukushima Daiichi nuclear accident.
 
Two months earlier, the utility reactivated the No.3 reactor at the plant. Two more reactors are running at its Takahama plant about 13 kilometers west of Ohi.
 
Although they all passed the government’s new regulations, attention is now focused on the threat of multiple accidents at these plants in the event of an earthquake and tsunami.
 
This summer, the government plans to hold its first drill based on a scenario that accidents have occurred simultaneously at the Ohi and Takahama plants.
 
In 2014, the Fukui District Court ruled against putting the No.3 and No.4 reactors at Ohi back online. It said estimated tremors of possible quakes at the plant are too optimistic. The ruling was appealed to a higher court, which has yet to decide the issue.
 

 

May 10, 2018 Posted by | Japan | , | Leave a comment

New Data for Unit 2’s Missing Fuel

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TEPCO published a Roadmap document right before leaving for Golden Week vacation. In this document is a 30+ page section of new data for unit 2’s missing fuel.
 
TEPCO has given varying explanations for unit 2’s meltdown and fuel location. Two muon scans have been completed for unit 2. The first found no fuel remaining in the RPV. A second scan by TEPCO claimed to have found some fuel in the bottom of the RPV, our analysis of the scan found otherwise. It is likely that all of the fuel inside the reactor vessel melted and all of it except for some residues is no longer in the RPV.
 
Fuel debris volume:
The volume of fuel debris inside unit 2 is difficult to calculate due to a number of factors. The debris is spread between multiple areas including the floor grate level, the pedestal floor and whatever debris may have burned down into the pedestal floor. The total volume of the fuel core is known for unit 2 but the exact size of the pedestal diameter is not known.
 
A fuel debris volume estimate was made for unit 1 based on known data and meltdown events at that reactor. Unit 1 is smaller than unit 2 in both fuel core size and size of the reactor structures. The general reactor building sizes and the fuel core sizes should be something that could roughly scale up for unit 2. Unit 1 estimate showed a fuel volume of all of the fuel and related melted structural materials as 60-100 cm deep.
 
Inside unit 2 about 50% of the pedestal floor was found to be covered with 70 cm of fuel debris. Additional fuel debris in an unknown volume is on the floor grate level. An unknown amount is burned down into the pedestal concrete basemat. Further fuel debris may be in lower reactor piping systems or the outer drywell floor. Unit 2’s fuel debris volume would also be reduced as the control rod drive array and bottom head of the reactor vessel are still intact. That large amount of metal structural material is known to not be part of the melted fuel debris in unit 2.
 
What has been found on inspection may be all of the fuel debris for unit 2 if a portion of the material is burned down into the pedestal basemat concrete. In most meltdown scenarios that is a given assumption unless the containment structure was heavily and repeatedly flooded with water at the time the fuel first dropped into the pedestal. With unit 2 that is an unlikely scenario.
 
There is an alternative possibility that a large amount of the radioactive materials in the fuel vaporized during the meltdown and escaped containment. This concept requires more investigation to confirm vaporization but this possibility for unit 2 is not completely ruled out. Fused microparticles containing nuclear fuel and other meltdown related materials have been found over a wide swath of Fukushima and beyond. Unit 2’s refueling floor blow out panel and reactor well containment gasket are one escape path for micro materials, steam and other gasses. Unit 2’s venting attempts are another concern. TEPCO has claimed the direct drywell venting of unit 2 didn’t work and the rupture disc for this system did not break as intended. TEPCO has provided no conclusive proof of this claim such as photos, video or other tangible evidence for this claim. Due to this, there is still the possibility that unit 2’s venting released some of these fused microparticles of fuel.
 
Radiation levels:
The radiation levels found in unit 2’s pedestal including a reading close to the fuel debris pile were between 7-8 Sieverts/hour. The high reading found along the CRD rail in 2017 was between 200-300 Sieverts/hour. These pedestal readings are drastically lower than what would be expected near an unshielded large pile of fuel debris.
By comparison, radiation levels along the outer containment wall in 2012 were within a similar range of the lower readings found on the CRD rail in 2017.
 
The elephant’s foot at Chernobyl, measured within the first year of the disaster, converted to Sieverts was 100 Sievert/hour.
 
Underwater readings in unit 1’s torus room near what is suspected fuel debris, taken in 2012 were 100,000 to 1 million Sieverts/hour.
 
Radiation levels near the fuel debris indicate that the top layers of debris may be mostly metallic materials with little fuel.
 
Radiation levels indicate that fuel bearing debris is not in the visible layer in the pedestal. (other possible locations – vaporized/vented, beneath the metallic layer, sml amounts in piping).

Roadmap document, section on unit 2:
http://www.tepco.co.jp/nu/fukushima-np/roadmap/2018/images1/d180426_08-j.pdf#page=3

TEPCO photo page for unit 2 findings:
http://photo.tepco.co.jp/date/2018/201804-j/180426-01j.html

May 10, 2018 Posted by | Fukushima 2018 | , , | Leave a comment

Fukushima ETHOS: Post-Disaster Risk Communication, Affect, and Shifting Risks

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26 May 2017
Abstract
ETHOS Fukushima is a risk communication (RC) program organized after the Fukushima nuclear accident by the International Commission on Radiological Protection and other international organizations supported by the Japanese government.
ETHOS has been hailed as a model RC that is participatory and dialogue-based. Yet the critical and feminist literature has shown the need for analyzing the power relations in participatory projects, and for analyzing affect as a target of management by neoliberal governmentality.
The affective work of ETHOS is characterized by narratives of self-responsibility, hope and anticipation, and transnational solidarity with Chernobyl victims. These resonate with the affective regime under neoliberalism that privileges self-responsibility, anticipation, maximization of emotional potential, and cosmopolitan empathy.
This particular regime of affect has been integral in shifting risk from the nuclear industry and the government to individual citizens. ETHOS Fukushima has supported continued residence in contaminated areas.
It has helped portray the reduction of government/industry responsibility as morally defensible, and the decision to stay in Fukushima as a free choice made by hopeful and determined citizens.
At the same time, ETHOS has helped characterize the state’s and the nuclear industry’s roles in cleaning up and compensating the victims as restricting individual freedom and demoralizing the local people.
The recent RC literature increasingly argues for a positive assessment of emotion, but this argument warrants careful analysis, as emotion is socially regulated and entangled in power relations.
Moreover, deploying affective tropes is a crucial technique of neoliberal governmentality, especially because of affect’s seemingly oppositional and external relationship to neoliberalism.

May 10, 2018 Posted by | Fukushima 2018 | , , , | 5 Comments

TEPCO offers virtual tour of Fukushima No. 1 plant on website

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May 5, 2018
Explanations are provided if the questions are clicked when passing through elevated land in front of the No. 1 reactor. (Captured from Tokyo Electric Power Co. website)
FUKUSHIMA–The crippled Fukushima No. 1 nuclear power plant is open for all to explore in a virtual tour on operator Tokyo Electric Power Co.’s website.
TEPCO released the “Inside Fukushima Daiichi” feature, only available on personal computers, so visitors can feel as if they are touring the decommissioning venue by car.
The service is aimed at helping more people understand the current state of the plant, also known as Fukushima Daiichi, after the nuclear crisis triggered by the 2011 Great East Japan Earthquake and tsunami.
While visitors can tour the plant grounds on the website, the radiation level around the displayed area is shown in the lower left portion of the monitor.
Front and side views of the No. 1 to No. 4 reactors, which suffered serious damage, can be seen up close.
In some sections, images taken both recently and immediately after the disaster are shown to offer comparisons. Explanations of the plant are provided in Q&A format for some areas as well.
A 360-degree view of the inside of the No. 5 reactor building, which has almost the same structure as the No. 1 to No. 4 reactors, and other facilities is also offered.
TEPCO is looking to provide an English-language version in the future.

May 10, 2018 Posted by | Fukushima 2018 | , | Leave a comment