PPPL-5351
Overview of the Fusion Nuclear Science Facility, a Credible
Break-in Step on the Path to Fusion Energy
Authors: C.E. Kessel, A. Khodak, G. H. Neilson,
P. Titus, K. Young
Abstract:
The Fusion Nuclear Science
Facility is examined
here as part
of a two step program
from ITER to commercial power plants. This
first step is considered mandatory to establish the materials and
component database in the real fusion
in-service environment before proceeding to larger electricity
producing facilities. The FNSF can be shown
to make tremendous advances beyond ITER, toward a power plant,
particularly in plasma duration and fusion
nuclear environment. A moderate FNSF
is studied in detail, which does not generate net electricity, but
does reach
the power plant
blanket operating temperatures. The full poloidal DCLL blanket is
chosen, with
alternates being the HCLL
and HCCB/PB. Several
power plant relevant
choices are made in order
to follow the philosophy
of targeted technologies. Any fusion core component must be
qualified by fusion relevant
neutron testing and
highly integrated non-nuclear testing before
it can be installed on the
FNSF in order
to avoid the high probability of constant failures in
a plasma-vacuum system. A range of missions
for the FNSF,
or any fusion nuclear facility on the path toward fusion power
plants, are established and
characterized by several metrics. A
conservative physics strategy is pursued to accommodate the
transition to ultra-long plasma pulses,
and parameters are chosen to represent the power plant regime to
the extent
possible. An operating space
is identified, and from this
one point is chosen
for further detailed analysis, with:
The space is shown to be robust to parameter
variations. A program is established for the FNSF to show how
the missions for
the facility are met, with a He/H, a DD and 5 DT phases. The
facility requires
- 25 years to complete its DT operation, including 7.8 years of
neutron
production, and the remaining spent on inspections and
maintenance. The DD
phase is critical to establish the ultra-long plasma pulse
lengths. The blanket
testing strategy is examined, and shows that many sectors have
penetrations for
H/CD, diagnostics, or TBMs. The hot cell is a critical facility
element in
order for the FNSF to perform its function of developing the
in-service
material and component database. The pre-FNSF R&D is laid
out in terms of
priority topics, with the FNSF phases driving the time-lines for
R&D
completion. A series of detailed technical assessments of the
FNSF operating
point are reported in this issue, showing the credibility of
such a step, and
more detailed emphasis on R&D items to pursue. These include
nuclear analysis,
thermo-mechsnics and thermal-hydraulics, liquid metal
thermohydraulics,
transient thermo-mechanics, tritium analysis, maintenance
assessment, magnet
specification and analysis, materials assessments, core and
SOL/divertor plasma
examinations.
Submitted to: Fusion Engineering and Design
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