Transmutation of Used Nuclear Fuel Workshop

Currently, the United States has over 90,000 MT of spent nuclear fuel that is primarily stored at the waste generation sites. One of ARPA-E’s goals is to develop technologies that improve the management, cleanup, and disposal of radioactive waste and spent nuclear fuel. Transmutation of this spent nuclear fuel to reduce the radiotoxicity, waste heat, storage volume, and storage time is an attractive solution to this challenging issue. Workshop participants lent their expertise to help define focus areas and metrics to shape a successful research program.

Workshop presentations covered the current state of the art in transmutation and implementation strategies for all transmutation-enabling technologies (current and advanced reactors, accelerator-driven systems, and non-neutron sources). Focused breakout sessions also addressed facility design, performance metrics, and economic factors guiding the success of a potential project.

Agenda: Tuesday, August 1st, 2023



8:00 – 8:30 AM

Registration, Breakfast, and Networking

8:30 – 8:35 AM

Welcome and Introduction to ARPA-E

David Tew, ARPA-E

8:35 – 8:55 AM

Workshop Introduction

Bill Horak, ARPA-E

8:55 – 9:30 AM

Participant Introductions

9:30 – 9:45 AM


9:45 – 10:15 AM

TPBARS Target Design

Guest Speaker: David Senor, Pacific Northwest National Laboratory

10:15 – 10:45 AM

Non-neutron Transmutation of Used Nuclear Fuel

Guest Speaker: Temitope Taiwo, Argonne National Laboratory

10:45 – 11:45 AM

Transmutation in Advanced Reactors

Moderator: Bob Ledoux, ARPA-E

Panelists: Pat Everett, Oklo, Inc.

Ed Pheil, Exodys Energy

Bret van den Akker, Ultra Safe Nuclear Corporation

11:45 AM - 1:00 PM


1:00 – 1:30 PM

Driven Subcritical Systems: SHINE’s Experience and Lessons Learned

Guest Speaker: Ross Radel, SHINE

1:30 – 1:45 PM

Introduction to the Breakout Sessions

Bill Horak, ARPA-E

1:45 – 3:00 PM

Parallel Breakout Sessions: Transmutation Enabling Technologies

  • Breakout Group 1, Current Generation Reactors
  • Breakout Group 2, Advanced Reactors
  • Breakout Group 3, Accelerators I
  • Breakout Group 4, Accelerators II
3:00 - 3:30 PM Break/Networking
3:30 - 4:45 PM

Parallel Breakout Sessions: Targets

  • Breakout Group 1, Transmutation Targets for Critical Systems
  • Breakout Group 2, Transmutation Targets for Sub-critical Systems
  • Breakout Group 3, Fuel Considerations
  • Breakout Group 4, Spallation Target Considerations
4:45 - 5:00 PM Summary of first day and closing

Day 2: Wednesday, August 2nd, 2023



7:30 – 8:30 AM


8:30 – 9:00 AM

Day 2 Welcome & Brief Recap of Day 1

Bill Horak, ARPA-E

9:00 – 9:30 AM

Transmutation Fuels

Guest Speaker: Todd Allen, University of Michigan

9:30 – 10:00 AM


Chris Vandervort, ARPA-E

10:00 – 10:30 AM


10:30 – 10:45 AM

Introduction to the Breakout Sessions

Bill Horak, ARPA-E

10:45 AM – 11:45 AM

Parallel Breakout Sessions: Performance Metrics

  • Metrics

11:45 – 12:00 PM



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