Japan Reactor Building is Tilting but Is Not a Risk, Operator Says

Posted in 原発事故, 放射能汚染 by shiro on 2012年6月28日

Japan Reactor Building is Tilting but Is Not a Risk, Operator Says |



Posted in 原発事故, 放射能汚染 by shiro on 2011年6月20日


Posted in 原発事故, 放射能汚染 by shiro on 2011年6月19日

[汚染水浄化システム | Photo

Tepco Halts Filtering of Tainted Water at Japanese Plant |

Filtering Water at Fukushima Nuclear Plant in Japan |

The new filtration system still faces many hurdles. The companies operating it, including Areva from France and Kurion from the United States, have little experience working with seawater. And Tepco must still dispose of the radioactive material that is being sifted out of the wastewater; it is mixed with a chemical agent to create a toxic sludge.

汚染水浄化、5時間で停止=装置で高線量、放射能の泥か-1週間以内の再開目指す | 時事ドットコム

【緊急提言】小出裕章さん 高濃度汚染水の処理方法 | YouTube

UN nuclear report shows Japan safety flaws | Al Jazeera English

IAEA の専門家はどんな報告をしたか

Posted in 原発事故 by shiro on 2011年6月2日

IAEA Expert Mission to Japan: Preliminary Summary | IAEA
IAEA調査団暫定的要旨(仮訳) | 外務省
〈IAEA 調査団報告書の全文〉

The results of this mission will be reported to the IAEA Ministerial Conference on Nuclear Safety at IAEA headquarters in Vienna from 20-24 June 2011. This is a preliminary summary report to provide immediate feedback to the Government of Japan.


• The Japanese Government, nuclear regulators and operators have been extremely open in sharing information and answering the many questions of the mission to assist the world in learning lessons to improve nuclear safety.


• The response on the site by dedicated, determined and expert staff, under extremely arduous conditions has been exemplary and resulted in the best approach to securing safety given the exceptional circumstances. This has been greatly assisted by highly professional back-up support, especially the arrangements at J-Village to secure the protection of workers going on sites.

・非常に困難な状況下において,サイトの運転員による非常に献身的で強い決意を持つ専門的対応は模範的であり,非常事態を考慮すれば,結果的に安全を確保する上で最善のアプローチとなった。 これは,非常に高度な専門的な後方支援,就中,サイトで活動している作業員の安全を確保するためのJビレッジにおける対応が大きな助けとなっている。[外務省仮訳]

• The Japanese Government’s longer term response to protect the public, including evacuation, has been impressive and extremely well organized. A suitable and timely follow-up programme on public and worker exposures and health monitoring would be beneficial.


• The tsunami hazard for several sites was underestimated. Nuclear designers and operators should appropriately evaluate and provide protection against the risks of all natural hazards, and should periodically update these assessments and assessment methodologies in light of new information, experience and understanding.


International Fact-Finding Mission Updates | IAEA

IAEA 問題点の詳細分析へ | NHKニュース

IAEA報告案 組織の「限界」が露呈した[社説] | 新潟日報社

6月1日 IAEAの本当の意図 小出裕章 (MBS) | 小出裕章 (京大助教) 非公式まとめ


Posted in 原発事故 by shiro on 2011年5月31日


Posted in 原発事故 by shiro on 2011年5月26日

Company Believes 3 Reactors Melted Down in Japan |

The plant’s operator also said that it was possible that the pressure vessels in the three stricken reactors, which house the uranium fuel rods, had been breached as well. But most of the fuel remained inside the vessels, the company said — far from a more severe nuclear meltdown in which molten fuel penetrates the ground, a calamity known as the “China Syndrome.”

Last week Tokyo Electric for the first time acknowledged that the fuel at one of the reactors, Unit 1, had most likely melted and fallen to the bottom of the reactor’s inner pressure vessel.

On Tuesday, Tokyo Electric said that meltdowns probably occurred at Units 2 and 3.

But many of the details of how the accident unfolded still remain murky. The 18-person team from the International Atomic Energy Agency includes experts from the United States, China, Britain and Russia. They will interview officials at Tokyo Electric, as well as Japanese nuclear regulators, before drafting a preliminary report next month.

Later speaking to reporters, Mr. Weightman expressed some understanding for the severe circumstances workers at the plant faced in the early hours of the crisis.

“In these severe circumstances, when roads, electricity, communications are severely disrupted, how do you manage to have an effective response?” he said.

Venting Failure in the Nuclear Reactors at Fukushima Daiichi |


Posted in 原発事故 by shiro on 2011年5月19日


U.S. Was Warned on Vents Before Failure at Japan’s Plant |

Five years before the crucial emergency vents at the Fukushima Daiichi nuclear plant were disabled by an accident they were supposed to help handle, engineers at a reactor in Minnesota warned American regulators about that very problem.

Five years before the crucial emergency vents at the Fukushima Daiichi nuclear plant were disabled by an accident they were supposed to help handle, engineers at a reactor in Minnesota warned American regulators about that very problem.

The Fukushima plant was designed by General Electric, and the venting systems that failed in Japan exists at similar plants designed by G.E. in the United States.

In a statement, James Klapproth, the nuclear energy chief consulting engineer at GE Hitachi, said that his company believed that the venting system would have operated in an accident within the “design basis” of the plant,” but that the Fukushima disaster was worse than what the plant was designed for. He said that the industry in this country had considered passive systems “at one time.”

Venting Failure in the Nuclear Reactors at Fukushima Daiichi |

@Daily Kos: Emergency vents in 31 U.S. … | Twitter

In Japan Reactor Failings, Danger Signs for the U.S. |


Posted in アメリカ, 原発事故 by shiro on 2011年5月17日

US NRC Makes Announcement From Washington: Fukushima Daiichi Situation Has “Definitely Improved” | YouTube]

Japan: U.S. Agency to Stop Monitoring Nuclear Plant |

“The conditions at the Japanese reactors are slowly stabilizing,” said William Borchardt, the agency’s chief staff official. “As conditions have continued to improve and the Japanese continue to implement their recovery plan, the N.R.C. has determined that it is time to adjust our response,” he said.

米NRC、福島第一原発の24時間監視を解除 | 読売新聞


Posted in 原発事故 by shiro on 2011年5月17日

小出裕章助教(京大原子炉実験所) 2011年4月1日 | Web Iwakami



Posted in 原発事故 by shiro on 2011年5月13日

Japanese Nuclear Reactor Damage Is Worse Than First Thought |

One of the most startling findings announced Thursday was that water levels in the reactor vessel, which houses the fuel rods, appeared to be about three feet below where the bottom of the fuel rods would normally stand. Ever since the reactor shut down, workers’ primary task has been to keep pouring water into the reactors to ensure the nuclear fuel remained covered so that it would not melt. But the new information suggests the fuel was uncovered for at least some time, probably early in the crisis.

That indicated that the exposed fuel has probably melted and slumped to the bottom of the vessel in little pellets, Junichi Matsumoto, a Tepco spokesman, said Thursday at a news conference.

David Lochbaum of the Union of Concerned Scientists, a nonprofit group usually critical of the nuclear industry, agreed that the temperature readings were a good sign.

He said he believed that the damage to the fuel at Reactor No. 1 was already finished, and that even if some fuel rods were still standing — and therefore exposed — they were no longer hot enough to keep melting.

“As bad as things are,” Mr. Lochbaum said, “they’re getting better.”

At the Nuclear Regulatory Commission in Washington, R. William Borchardt, the top staff official, briefed the five members of the commission on Thursday morning about the new disclosures, but did not describe them as major developments. Over all, he described the status of the Fukushima complex as “not exactly stable, but you might say that they’re static.”

原子炉で想定以上の水漏れ、燃料落下の可能性―福島第1原発 | WSJ日本版

Nuclear fuel rods may have mostly melted | The Daily Yomiuri

Fukushima: Er, Sorry…Worse Than We Thought. |

5月12日 メルトダウンだが最悪シナリオ回避 小出裕章 | 小出裕章 (京大助教) 非公式まとめ

メルトダウンは3月11日…初動の遅れ裏付け | 読売新聞

東日本大震災:福島第1原発事故 1号機空だき10時間以上 専門家「公表遅すぎる」 | 毎日新聞

5月16日 溶けた燃料で格納容器に穴 小出裕章 | 小出裕章 (京大助教) 非公式まとめ

【放射能漏れ】1号機、地震16時間後にメルトダウン 4号機の爆発は3号機の水素逆流が原因か | MSN産経ニュース

2号機と3号機の炉心も損傷―福島第1原発 | WSJ日本版