Japan items - Nitrogen injection stops again , reactor radiation at unit 2 disables robot in two hours , debris plans / schemes to spread the contamination abound

Nitrogen injection stopped again

Posted by Mochizuki on April 7th, 2012 · No Comments

Nitrogen injection for reactor 1~3 stopped again, Tepco reported on 4/7/2012.
They started the back-up unit one hour later, but still the reason is not verified.
Tepco states, it might be because of the clogging filter.

Nitrogen injection stopped 3 times only in one month. Including the leakage of highly contaminated water, troubles are happening almost everyday.

Source

窒素注入装置また停止＝１カ月で３度目、東電「調査中」
東京電力福島第１原発事故で、東電は７日、１～３号機の格納容器と圧力容器に窒素を注入する装置が停止したと発表した。１時間後に予備機を起動し、窒素注入は再開されたが、原因は分かっていない。同社は「調査中だが、フィルターの目詰まりも推定される」としている。
この１カ月で窒素注入装置の停止は３回目。汚染水の漏れなども含め、福島第１原発では連日のようにトラブルが続いている。（2012/04/07-19:39）

and....

Robot destroyed within 2 hours in reactor 2

Posted by Mochizuki on April 7th, 2012 · No Comments

Following up this article..73Sv/h in container vessel

In this level of radiation, even a disaster dealing robot is collapsed within less than 2 hours.
In Fukushima plants, robot called Quince is used, which is developed by Chiba institute of technology and Tohoku university. Assistant professor Mizutani from Tohoku university states,
“The bottle neck to develop a robot for radioactive circumstances is the semiconductor.Semiconductor is extremely sensitive for radiation. Semiconductor parts of robot used in space are shielded by lead, which is against gamma ray, but lead can’t be used for Quince because it kills cavalry.Technical specification requires Quince to stand only over 3Sv/h. In total, it’s just over 100Sv.”

With this level of the specification, Quince can’t last longer than 2 hours in reactor2. If it’s 3Sv/h to stand, Quince can’t last longer than 1 hour and 20 minutes.

2号機格納容器内の線量ではロボットですら2時間で破壊されることが分かりました。
現在、福島ではクインスと呼ばれる災害対応ロボットが使われていますが、開発段階で放射線に耐える能力を評価した東北大大学院の水谷圭司准教授はこう言います。
「高放射線下で動くロボットを開発する上で一番の障害になるのはロボットを制御する半導体部分です。半導体は放射線に著しく弱い。放射線が強い宇宙空間で使われる半導体はガンマ線から守るために厚い鉛で遮蔽されていますが、クインスでは機動性が落ちてしまうので鉛が使われていません。
放射線に耐える能力として、技術仕様ではたった毎時3シーベルト以上、累計で100シーベルト（100グレイ）となっています。」

2号機格納容器では73Sv/hが検出されましたが、この技術仕様では2時間ももたないことになります。
仮に技術仕様で求められる3Sv/hぎりぎりだとすると、わずか1時間20分で破壊されてしまいます。

and....

Aichi Prefecture will accept up to 1 million tons of rubble from earthquake and tsunami-ravaged areas of northeastern Japan.

Aichi is one of 35 prefectures that responded to a central government request by April 6 to accept debris from the Tohoku region.

Aichi's decision came 13 months after the magnitude-9.0 Great East Japan Earthquake.

The central government is seeking to secure agreements from prefectural authorities across Japan to accept some 4 million tons of wreckage from Iwate and Miyagi prefectures.

The government on March 16 sent letters in Prime Minister Yoshihiko Noda's name to 35 prefectures and 10 major cities that had yet to make clear whether they would accept rubble.

In asking for their cooperation, the letters set April 6 as the deadline for a response.

More areas are leaning to helping out, while some are determined not to take part.

In Kyoto Prefecture, five cities and towns, including Maizuru, said they are considering the government's request.

Sapporo rejected the request on grounds the central government is unable to offer guarantees that radiation levels are safe.

Tokushima Prefecture said no municipalities under its jurisdiction intend to accept rubble. It criticized the government for not offering a sufficient explanation.

The government late last month asked eight prefectures and eight major cities that had indicated a willingness to dispose of debris to accept 910,000 tons of rubble.

Tokyo already plans to dispose of 500,000 tons.

and...

Hosono makes new debris plea to Fukushima towns

Kyodo

Environment Minister Goshi Hosono repeated his request Saturday for temporary storage sites to be built in towns around the crippled Fukushima No. 1 plant for radiation-tainted soil and debris before its eventual disposal.

If you build it, they won't come: Environment Minister Goshi Hosono addresses officials from Naraha, Fukushima Prefecture, on Saturday in the town of Iwaki over the central government's plan to build a storage facility for irradiated soil. KYODO

But representatives of Naraha, one of the three towns targeted, refused to budge, according to people who attended a meeting Saturday in Iwaki, Fukushima Prefecture. Naraha's municipal authorities have been based in Iwaki since the nuclear crisis began.

Hosono said the final dump site will be built outside the prefecture, telling Naraha's officials that "this is an issue that has to be resolved by nationwide efforts."

But that wasn't enough to convince them. "How could our children live in such an environment?" one official asked. "Is there any guarantee that government will secure the location for the final dump site?"

Naraha's municipal assembly has unanimously adopted a resolution to oppose the construction of such a storage site in the town.

40,000 tons U.S.-bound

The Environment Ministry said more than 40,000 tons of debris from the March 2011 tsunami are expected to reach North America's West Coast by February 2013.

The debris is part of the 1.33 million tons washed into the ocean from Iwate, Miyagi and Fukushima prefectures.

"Japan is not obligated to recover debris under international law, but we will hold talks with the U.S. and Canada to prevent it from causing problems, such as endangering ships," a ministry official said Friday.

According to ministry estimates, 1.2 tons of half-submerged debris will reach the West Coast around October.