Ex-nuclear engineer’s proposal Mar23

A former nuclear power plant engineer Yuzo Uehara continues to raise his voice to act immediately to solve the crisis at Fukushima Daiichi Nuclear Power Station.
These are some of the tweets he made today.

福島原発への低減0730;4日前から発信のカルバート工法はコンクリートでなくコンテナを並べる・積む・ひとつでもあれば高線量の遮蔽・低減、除染がで き並べてアクセス通路に。鉛を外装・内装すれば高い線量現場に近接して設置できる。そこに大口径配管ラーダをもうければ注水が大量で精度よい。

Proposal 0730: In the culvert method, I’ve been proposing since 4 days ago, use not concrete but containers and line them up, then pile them up. Even if there were only one, it can block, reduce, and decontaminate radiation. Line them up and make accessing paths. If you install lead outside and inside, you can install them near the high radiation sites. If you put a large diameter pipe ladder there, you can pour water in large amount and precisely.

福島原発231840;好転するが、被ばく遮蔽と低減を図からねば。注水と復旧工事もっと迅速化できる。安全最優先すると同時に工事進捗できるカル バート工法(コンクリート又はコンテナ利用)。鉛等装着すれば極めて高い線量でも対応できる。現地復旧工事がもっと多方向から着手できせめられる。

Proposal 231840: The situation would get better, but we have to do something to block and reduce radiation. We can make pouring water and recovery work quicker. With the culvert method (using concrete or containers), we can give safety the first priority as well as make progress in work. If lead and such were installed, we can work under higher radiation. Recovery work at the site can get done from the various directions.


From the beginning of the disaster, as an ex-nuclear plant designer, I calculated and proposed a specific idea that gets every manpower and equipment together into the site with the culvert method using containers or such and the Carrier/Cask Handling System. The culvert method is effective now. I want those who involved get an idea like this quickly.

福島原発232030;遮風壁は建物の1,5倍の高さで遮風壁内の風速は三分の一に。サイトの陸側離れた場所にたてば外部への汚染限定。定期にサイト内を ヘリ散水。サイト地面線量あがるがカルバート内でアクセス。海に流れぬよう溝必要。遮風壁は網でよく高さ60m。ヤマセ対策みよ。

Proposal 232030: If wind block walls were 1.5 times higher than a building, the wind speed decreases to 1/3 with in the walls. If they were set up somewhere in the inland side and away from the site, we can limit contamination to the outside. Regularly pour water from a helicopter at the site. Ground radiation at the site would go up, but we can access through the culvert. Ditches are required to prevent water from flowing out to the sea. Wind block walls can be nets with 60m high.

I urge the international community to endorse his proposal or present better ideas to solve the crisis NOW.


Proposal transaltion 191345

Yuzo Uehara’s proposal (tweet 191345)


(rough translation)
191345: For workers of electric work, equipment adjustment, and welding&piping work at the site, build lead houses in locals to make absolutely sure the protection against radiation.

Proposal transaltion 181150

Yuzo Uehara’s proposal (tweet 181150)

福島原発への提言181150;予備変圧器活きて朗報。 さて念のためカルバート工法最終。ユニット最終端は鉛隔壁厚さ1m。真ん中直径50センチ機材搬出ハッチ、配管直径15センチ、配線直径3センチの貫通穴各1個のためペネトレーシヨン装置を設け外部に機材・配管・配線がだせる。(終)

(rough translation)
181150: Just in case, here’s the last part of the culvert method. The unit’s end has the lead bulkhead with 1m thick. In the center, install a penetration equipment for a equipment hatch with 50cm in diameter, a pipeline with 15cm in diameter, and a penetration hole for wiring with 3cm in diameter, then we can put equipment, a pipeline, and wiring outside. (End)


  • I’m not translating parts that are not related to his proposed method. He sometimes made some comments about the situation in Fukushima Daiichi at the time of tweeting.
  • Proposal transaltion 1830

    Yuzo Uehara’s proposal (tweet 1830)


    (rough translation)
    1830: For the curved part, an elbow unit is used. In places where the jack cannot be used because of high radiation, use a bulldozer whose cockpit is armed with 10cm thick lead and make it easy to install. When radiation gets higher, install lead blocks on the outside of the unit accordingly.

    Proposal transaltion 1820

    Yuzo Uehara’s proposal (tweet 1505)

    福島原発への提言1820;カルバートユニットの延長にはヘリコプターは効率的、線量高いと限界ある。カルバートユニットは油圧ジャッキ押し出し 工法にて延長。平地なので容易。線量高くなるに従いユニット内部に鉛ブロックで壁天井にはり、かつ積む。内部空間幅60高さ120センチは確保。

    (rough translation)
    1820: Foe the culvert unit extension, helicopters are effective, but it could be limited if radiation were high. The culvert unit is extended by the an oil pressure jack pushing system. Easy because it’s flat. When radiation gets higher, install lead blocks on the walls and the ceiling inside of the unit accordingly. The inside space should be at lease 60cm wide and 120cm high.

    Proposal transaltion 1803

    Yuzo Uehara’s proposal (tweet 1803)

    福島原発への提言1803;コンクリートカルバートユニット長さ3mの300m敷設のスタート点は5・6号側護岸。海上クレーン100トン位で船から カルバートユニットを水切りし設置。同ユニットの先端に油圧ジャッキを付け前に置いたユニットを油圧ジャッキと接ぎ手で押し次々に延長していく。

    (rough translation)
    1803: The starting point of the 300m installation of the 3m long concrete culvert unit is at the bank protection of the Unit 5 & 6. By a 100-ton-class sea crane, the culvert unit is weathered and installed. At the top of this unit, an oil pressure jack is installed, and the unit placed in front is pushed and extended by the jack and a coupling.

    Proposal transaltion 1525

    Yuzo Uehara’s proposal (tweet 1525)


    (rough translation)
    1525: Because lead blocks placed inside of the culvert unit, if it were extended to 250m, it would reach to the high radiation point, and there would be a small space left for workers passing through. The top part is 1m thick lead wall; and manhole, pipelines, and ventilation are installed in the center part for penetration. (cont.)