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Published date

August 08, 2019

External detection and measurement of hydrogen gas inside the piping


【Current situation】
In the south area of Fukushima Daiichi Nuclear Power Station Unit 1 R/B ground floor, securing enough working areas for PCV investigation and fuel debris retrieval are very difficult since there are places where the dose is extremely high due to contamination of the inside of the Atmospheric Control (AC) piping, etc.
We would like to cut and remove the piping that is the radiation source.
However, it is assumed that some of the piping contains hydrogen gas.
So it is required to select the appropriate method to cut and remove it after confirming the existence/absence of hydrogen gas and the stagnant flow rate.

※ “absence” represents the situation where the hydrogen gas concentration is well below the Lower flammable limit (4%).

▲ The image of the environment around the piping taken by γ camera

① The detection and measurement of hydrogen must be done from outside the piping, without cutting. The basic information of the piping is below:
- Piping material : mainly carbon steel, stainless steel etc.
- Piping wall thickness : about 3mm to 20mm
- piping diameter : about 25mm to 350mm

② The target area is highly radioactive. The equipment must work under high radiation environment and be able to be operated remotely. The assumed environment is as below:
- Air radiation dose in the south area of R/B ground floor: about 1200 mSv/h at high area

【Our needs】
In order to solve the above-mentioned problems, we are seeking for non-destructive technologies and devices that can detect and measure the existence/absence of hydrogen gas in the piping from the outside. In addition, since the usage environment is a highly radioactive, the technologies and devices with radiation resistance is desirable.

【Detailed information】
○Applicable / Inapplicable proposals
*Applicable proposals
We accept proposals that satisfy all the following requirements.
・It must work under high radiation environment(Maximum1200mSv/h)
・Remotely operated
・Small enough to be carried through the area of the piping (narrow passage with a height of about 2m and a width of about 1m)

*Inapplicable proposals
The proposals that don’t comply with all requirement in “Applicable proposals” are not being called for at this time.

・In order to safely install the equipment in the target area, the equipment should be able to move and set itself on its own; or placed by remote control; or be carried by a small remote controlled machine that can carry up to around 70 kg.

○Development Level
The proposal must be at level 4 or 5 of the following development levels.
▶︎4.efficiency verified through feasibility study
 3.feasibility study phase
 2.planning & development phase
 1.idea phase

【Submission deadline】
November 30, 2019 (JST)
*Application period and contents are subject to change without notice.
*After submission we may ask you additional questions during the above period.

● Please make sure you read and understand the “Constraints” before your submission. Only proposals that comply with these “Constraints” will be submitted to TEPCO.
● If mandatory questions are not answered or not appropriately answered, the proposal will not be submitted to TEPCO.
● Please move to the submission form from the "Submit" button at the bottom of this page and fill in your proposal.

※ This offering is only open to organizations such as companies or research institutes. Please understand that proposals from individuals are not called for.

When you propose your ideas, TEPCO CUUSOO account is needed.
* Please be aware of the submission deadline.

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