Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*

Gebhart III, Trey; Baylor, Larry; Ericson, Milton; Meitner, Steven; Qualls, A L.; Rasmussen, David

doi:10.1088/1741-4326/ac1bc4

Title: Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*

Abstract

Shattered pellet injection (SPI) has been selected as the baseline technology for the disruption mitigation (DM) system for ITER. Typical SPI utilizes cryogenic cooling to desublimate low pressure (<100 mbar) gases onto a cold zone within a pipe gun barrel, forming a cylindrical pellet. Pellets are dislodged from the barrel and accelerated using either a gas driven mechanical punch or high-pressure light-gas delivered by a fast-opening valve. SPI technology developed at Oak Ridge National Laboratory is currently deployed and operational on DIII-D, JET, and KSTAR. These SPI systems are used in experiments for physics scaling to ITER thermal mitigation and runaway electron dissipation/avoidance. The pellet sizes used for these machines are in the range of 4 to 12.5 mm in diameter with length to diameter ratios (L/D) of ~1.5. The current plan for ITER SPI is to utilize pellets that are 28.5 mm in diameter with an L/D of ~2. Furthermore, the large pellet sizes, high steady-state magnetic fields, and limitations of operating in a radiation environment render much of the current technology unusable. In addition to technology improvements, a deeper understanding of pellet material properties, formation, and release is being developed for implementation in future SPI designs, specifically ITER.

Authors:

^[1];

^[1]; Rasmussen, David ^[1]

Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Publication Date:: Thu Sep 02 00:00:00 EDT 2021

Research Org.:: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:: USDOE Office of Science (SC)

OSTI Identifier:: 1820806

Grant/Contract Number:: AC05-00OR22725

Resource Type:: Accepted Manuscript

Journal Name:: Nuclear Fusion

Additional Journal Information:: Journal Volume: 61; Journal Issue: 10; Journal ID: ISSN 0029-5515

Publisher:: IOP Science

Country of Publication:: United States

Language:: English

Subject:: 70 PLASMA PHYSICS AND FUSION TECHNOLOGY

Citation Formats


                    Gebhart III, Trey, Baylor, Larry, Ericson, Milton, Meitner, Steven, Qualls, A L., and Rasmussen, David. Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*.  United States: N. p., 2021. 
Web.  doi:10.1088/1741-4326/ac1bc4.

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                    Gebhart III, Trey, Baylor, Larry, Ericson, Milton, Meitner, Steven, Qualls, A L., & Rasmussen, David. Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*.  United States.  https://doi.org/10.1088/1741-4326/ac1bc4

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                    Gebhart III, Trey, Baylor, Larry, Ericson, Milton, Meitner, Steven, Qualls, A L., and Rasmussen, David. Thu .  
"Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*".  United States.  https://doi.org/10.1088/1741-4326/ac1bc4.  https://www.osti.gov/servlets/purl/1820806.

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@article{osti_1820806,

  title        = {Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*},

  author       = {Gebhart III, Trey and Baylor, Larry and Ericson, Milton and Meitner, Steven and Qualls, A L. and Rasmussen, David},

  abstractNote = {Shattered pellet injection (SPI) has been selected as the baseline technology for the disruption mitigation (DM) system for ITER. Typical SPI utilizes cryogenic cooling to desublimate low pressure (<100 mbar) gases onto a cold zone within a pipe gun barrel, forming a cylindrical pellet. Pellets are dislodged from the barrel and accelerated using either a gas driven mechanical punch or high-pressure light-gas delivered by a fast-opening valve. SPI technology developed at Oak Ridge National Laboratory is currently deployed and operational on DIII-D, JET, and KSTAR. These SPI systems are used in experiments for physics scaling to ITER thermal mitigation and runaway electron dissipation/avoidance. The pellet sizes used for these machines are in the range of 4 to 12.5 mm in diameter with length to diameter ratios (L/D) of ~1.5. The current plan for ITER SPI is to utilize pellets that are 28.5 mm in diameter with an L/D of ~2. Furthermore, the large pellet sizes, high steady-state magnetic fields, and limitations of operating in a radiation environment render much of the current technology unusable. In addition to technology improvements, a deeper understanding of pellet material properties, formation, and release is being developed for implementation in future SPI designs, specifically ITER.},

  doi          = {10.1088/1741-4326/ac1bc4},

  journal      = {Nuclear Fusion},

  number       = 10,

  volume       = 61,

  place        = {United States},

  year         = {Thu Sep 02 00:00:00 EDT 2021},

  month        = {Thu Sep 02 00:00:00 EDT 2021}

}

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Works referenced in this record:

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journal, September 2010

Commaux, N.; Baylor, L. R.; Jernigan, T. C.
Nuclear Fusion, Vol. 50, Issue 11
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Herfindal, J. L.; Shiraki, D.; Baylor, L. R.
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Park, SooHwan; Lee, KunSu; Baylor, Larry R.
Fusion Engineering and Design, Vol. 154
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Experimental Pellet Shatter Thresholds and Analysis of Shatter Tube Ejecta for Disruption Mitigation Cryogenic Pellets
journal, June 2020

Gebhart, T. E.; Baylor, L. R.; Meitner, S. J.
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Li, Y.; Chen, Z. Y.; Wei, Y. N.
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Similar Records

Title: Recent progress in shattered pellet injection technology in support of the ITER disruption mitigation system*

Abstract

Citation Formats

Demonstration of rapid shutdown using large shattered deuterium pellet injection in DIII-D journal, September 2010

Injection of multiple shattered pellets for disruption mitigation in DIII-D journal, September 2019

Analysis of the Shattered Pellet Injection Fragment Plumes Generated by Machine Specific Shatter Tube Designs journal, December 2020

Experimental results of multiple shattered pellet injection systems in KSTAR journal, March 2021

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Deployment of multiple shattered pellet injection systems in KSTAR journal, May 2020

Experimental Pellet Shatter Thresholds and Analysis of Shatter Tube Ejecta for Disruption Mitigation Cryogenic Pellets journal, June 2020

A new disruption mitigation valve (DMV) and gas flow in guiding tubes of different diameter journal, March 2011

Design of a shattered pellet injection system on J-TEXT tokamak journal, October 2018

Demonstration of rapid shutdown using large shattered deuterium pellet injection in DIII-D
journal, September 2010

Injection of multiple shattered pellets for disruption mitigation in DIII-D
journal, September 2019

Analysis of the Shattered Pellet Injection Fragment Plumes Generated by Machine Specific Shatter Tube Designs
journal, December 2020

Experimental results of multiple shattered pellet injection systems in KSTAR
journal, March 2021

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journal, June 2016

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journal, June 2020

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journal, October 2018