Comments on Speed-up of HAPL Approach to Fusion

1
Comments on Speed-up of HAPL Approach to Fusion

• John Sheffield
• JIEE
• November 2005

2
High Volume Plasma Based Neutron Source

• The IEA study, UCLA-ENG-95-111,
• Abdou et al, gives a well reasoned set of
  arguments about what is needed for nuclear
  testing and development of reliable blankets to
  meet the availability of an MFE DEMO reactor.
• Without a Volume Neutron Source in MFE, it is
  essentially impossible to do adequate testing -
  even with the original extended- performance ITER
  and IFMIF!

3
IFE Needs for Nuclear Testing

• Interestingly, the IFE requirements are less
  stringent than for an MFE DEMO.
• Either there will be a flowing lithium blanket
  or, in the case of a dry wall, the wall will be
  operated at lower neutron flux to handle the
  blast.
• Nevertheless, volume testing of nuclear
  components may well set the critical path to
  realization of an IFE DEMO. An VNS is essential

4
Neutron Fluence Required for HAPL Power Plant

• Assume HAPL DEMO fusion power is 1750 MW, 50
  availability and 70 of it hits the walls as
  neutrons i.e., 1225 MWn.
• Wall at 10.5m, av. neutron flux 0.88 MW/ m2.
• The average neutron fluence 0.44 MW.yr/ m2.
• If the Demo runs for 10 to 20 years, required
  chamber material lifetime negligible swelling
  requires testing to gt 4.4 MW.yr/ m2.
• Surface may need regular damage repair.

5
VNS Neutron Flux and Fluence

• Initial operation 25 MW, with 17.5 MWn.
• 1 year commissioning, 2 years at 20 capacity
  factor, and 3 years at 40 capacity factor.
• Ultimately operation at 150 MW.
• Assuming 2 years to rebuild after shutting down
  the first version - Remember it is now a highly
  activated facility!
• 1 years commissioning, 1 year at 25 capacity
  factor and then 50 capacity factor.

6
VNS Integrated Neutron Fluence
Year8 MW.yr/ m2 At 1 meter MW.yr/ m2 At 2 meters
2014 0.28 0.07
2015 0.56 0.14
2016 1.12 0.28
2017 1.68 0.42
2018 2.24 0.56
2019 Upgrade to 150 MW Upgrade to 150 MW
2020 Upgrade to 150 MW Upgrade to 150 MW
2021 4.3 1.1
2022 8.5 2.1
2023 12.7 3.2
2024 16.9 4.3
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Tritium Usage

• In the initial phase at 25 MW and 40 capacity
  factor the demand would be
• 0.56 kg/yr.
• At 150 MW and 50 capacity factor.
• Tritium usage 4.2 kg/yr.
• Substantial tritium breeding will be needed.

8
What VNS

• Heresy, but what ever can be done fastest is
  needed to speed-up nuclear testing.
• However, each approach to IFE will need its own
  repetitively pulsed D-T facility to develop
  required capabilities for DEMO.
• Ergo, need more than one Facility.