Review of tritium permeation barriers l.jpg
This presentation is the property of its rightful owner.
Sponsored Links
1 / 8

Review of Tritium Permeation Barriers PowerPoint PPT Presentation


  • 108 Views
  • Uploaded on
  • Presentation posted in: General

Materials & Engineering Sciences Center. Atoms to Continuum. Review of Tritium Permeation Barriers. Rion Causey Sandia National Laboratories Livermore, CA 94550 Presented at: ITER TBM Project Meeting, UCLA February 23-25, 204. Materials & Engineering Sciences Center.

Download Presentation

Review of Tritium Permeation Barriers

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Review of tritium permeation barriers l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

Review of Tritium Permeation Barriers

Rion Causey

Sandia National Laboratories

Livermore, CA 94550

Presented at: ITER TBM Project Meeting, UCLA

February 23-25, 204


Non replenishing tritium permeation barriers do not work well l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

Non-Replenishing Tritium Permeation Barriers Do Not Work Well!!

For various reasons, permeation barriers have not provided the reduction

in permeation that has been desired.

Barriers that have provided Permeation Reduction Factors (PRF’s) of 1000 or greater in the laboratory, have later provided PRF’s of 10 or less in the real application.

Most of the permeation barriers that have provided PRF’s of 1000 or greater consist of oxide layers. The primary reasons for the reduction in PRF’s during the application include chemical erosion or cracking of the barrier.


Some materials naturally have lower permeabilities for hydrogen isotopes l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

Some materials naturally have lower permeabilities for hydrogen isotopes

Tungsten has a very low

permeability, but is too heavy.

Aluminum also has a low

permeability, but it has no

strength at 500oC.

At 500oC, copper is about 30 times lower than Manet


What amounts of tritium would be released based on these permeation coefficient l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

What amounts of tritium would be released based on these permeation coefficient??

Consider the following hypothetical situation (provided to me by Dai Kai)

The heat exchanger will operate at a temperature of 500oC.

The surface area of the heat exchanger will be 10,000 m2.

The pressure of tritium in the heat exchanger will be 1 Pa.

Assume a wall thickness of 2 mm.


The release rates are high l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

The release rates are HIGH!!

Permeation coefficient for Manet is about 3x10-6 cc(stp)/(s-cm-atom1/2)

The permeation rate is approximately 100 grams/day

Using a duplex coextruded steel/copper tube reduces the effective permeation coefficient by about 30, yielding about 3 grams/day (30,000 Ci/day)

Even with a permeation barrier on the Manet tubes (and the achievement of a PRF of 1000) still yields a permeation rate of 0.1 grams/day (1000 Ci/day)


As recommend by dai kai i have looked into a product by alon processing inc l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

As recommend by Dai Kai, I have looked into a product by Alon Processing Inc.

Alon Processing Inc. produces heat exchanger tubes that have aluminum diffused into the base steel.

Aluminum at concentrations of approximately 20at% exist for the first 0.5 to 1.0 mm. They claim this is not a coating, but a material that has an alloyed region quite deep into the steel.


Hydrogen permeation has been measured for these alonized tubes l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

Hydrogen permeation has been measured for these alonized tubes

In the permeation experiments, a mixture of water, acetic acid, sodium chloride with hydrogen sulfide added was used at the hydrogen source.

For the alonized layer on the inside only, a PRF of 100 was achieved.

When the alonized layer was placed on both inside and outside, a PRF of 500 was achieved.


Conclusions l.jpg

Materials & Engineering

Sciences Center

Atoms to Continuum

Conclusions

In future tritium burning fusion devices, holding the tritium permeation rates to reasonable values is going to be very difficult.

It is likely that a double tube design or an intermediate heat exchanger will be required.

The material produced by Alon Processing Inc. appears very interesting and should be tested again for hydrogen permeation with appropriate gas pressures.


  • Login