Reducing the Costs of Targets for Inertial Fusion Energy

G.E. Besenbruch, D.T. Goodin, J.P. Dahlburg, K.R. Schultz,A. Nobile1, E.M. Campbell

General Atomics, P.O. Box 85608, San Diego, California 92186-56081Los Alamos National Laboratory, Albuquerque, New Mexico

HAPL Project ReviewPleasanton, California

November 13-14, 2001(IFSA2001 Paper #1113)

Concept for “HILIFE-II” IFE 1000 MW(e) Power

Plant (Chamber radius = 3 meters)

Feasibility of economical target fabrication is a critical issue for IFE power plants

A number of power plant conceptual designs are available pulsed power systems that operate at ~6-10 Hz

Must supply about 500,000 targets per day with:- precision geometry, and cryogenic, layered DT fill

.... Cost reductions from about $2500 to about $0.25 per target are needed for economical electricity production

Preliminary target designs have been identified

LLNL Close-Coupled HI Target

NRL RadiationPreheat Target

Some Expected Direct Drive Specifications

Capsule Diameter 4 mmShell Wall Thickness 200 mFoam shell density 20-120 mg/ccOut of Round <1% of radiusNon-Concentricity <1% of wall thicknessShell Surface Finish 500 Angstroms RMSIce Surface Finish <2 m RMS

The heavy-ion driven target has a number of different regions

Regions of low-density foams

and unique materials

Nuclear Fusion 39(11)D. A. Callahan-Miller

and M. Tabak

Other Potential Direct Drive

Target Concepts

Empty Outer Foam

Thick Outer

Capsule

0.25 g/cc foam

Seal, DT

Dense ablator

Seal, DT

Cost reductions of four orders of magnitude are challenging - but feasible

GDP

PAMSGas cooled reactor fuel particle with 4

coating layersFuel particle scaleup experience is

encouraging for IFE

Inertial fusion energy target

~3500 µm

~1000 µm

Current cost~$2500/target

.... GA has previously used fluidized bed technology to reduce costs of coated nuclear fuel particles and produced over 1011 particles!

Technological improvements lead to dramatic changes in products (i.e. Moore's Law)

Technology Review, C. Mann, May/June 2000

.... The number of transistors on a chip increased 4 orders of magnitude from 1971 to 1999

Moore's law analogies can be applied directly to cost reductions

Year

Main memory cost per byte (pence)

The cost of computer memory decreased by 106 between 1970 and 1990. This was achieved through reductions in process costs and improvements in manufacturing technology.

Ref: http://www.cse.dmu.ac.uk/~cfi/Networks/WorkStations/Workstations5.htm

One can estimate IFE target production costs beginning with current experimental-target costs

One can find the approximate cost per current-day target byTotal Project Cost/ Number of Delivered Targets = ~$2500 (capsule only)

However, there are tremendous differences in the program requirements - and in the consequent approaches to manufacture

Item Experimental Program IFE ProgramProduction Rate Relatively Small (~2500 targets per year by GA) 500,000 per dayFOAK Costs Very high - targets always vary Essentially noneCharacterization Extensive - individual details needed Statistical samplingProduct Yield Low - product varies, small amounts needed HighBatch sizes Small - small amounts needed (<100) Large

Eliminating FOAK Costs

Reducing Characterization

Increasing Yield

Increasing Batch Sizes

… IFE target cost reductions will be achieved

by

Costs will be dramatically lower when targets are identical - eliminates First of a Kind (FOAK) costs

Currently delivered targets are nearly always unique - with most of the labor going to development and trial runs

We estimate the average FOAK labor now as hundreds of hours

These costs will be minimal for IFE production

Example - Dopants and wall thicknesses vary on each batch ordered for experiments.

Today, few targets are made more than once!

.... For IFE, a single type of target is repeatedly produced, and FOAK development costs are essentially eliminated

02468101214161820

Wal

l thi

ckne

ss, µ

m1 2 3 4 5 6 7 8 9 1011121314151617

target batch #

X-GDPM-X-GDPM-GDP GDPM=Metal X=Halogen

Large savings can be achieved in characterization and QC

Currently, shot-quality targets are highly characterized before delivery “pedigree” with detailed data on individual targets.

Current manual characterization - ~8 hours per shell

Future automated system for dimensional

inspection of IFE target foam shells

For the IFE Target Fabrication Facility, the cost of QC is reduced by:- reduced precision in IFE target designs- statistical sampling for process control- only periodic in-depth checks- automated characterization equipment

.... Major characterization cost reductions can be achieved

Process development focusing on routine production will result in high product yields

First-of-a-kind thin walled capsules have low yield (imploded

during solvent extraction)

After R&D and applying the science to process conditions, implosions are

almost eliminated.

FOAK batches: low yields (1-5%)

High Yields (like chemical industry

processes) of >95% but same operations cost

Target Fabrication

Process Development

Programs

9" ID nuclear fuel coater

IFE target development programs must provide the technology basis for batch size increases and high yields

aq DropletgenerationAir dry Non aqueouspolymer solutionAqueous phaseSolid shellAqAqAq Loss oforganic solventAq

Microencapsulation is inherently a high-volume production process

Scaleable ProcessesMicroencapsulation (shells)Fluidized bed coatings (shells)Interfacial polycondensation (seal coats)Sputter-coating (high-Z coatings)Casting (foams, hohlraum cases)Assembly (hohlraums, cryogenic, remote)

Example - bounce-pan holds 4-100

shells for coating

Bounce Pan

Coating

Example - two 9" diameter fluidized

bed coaters can produce 500,000 particles per day

MOVING

CRYOSTAT

LA CAVE

MOVING CRYOSTAT TRANSPORT CART

ROOM 157

UR TRITIUM

FILLING

STATION

DT HIGH

PRESSURE SYSTEM

GLOVEBOX

MOVING CRYOSTAT ELEVATOR

LOWER PYLON

UPPER PYLON

TARGET

CHAMBER

FILL/TRANSFER

STATION

Glovebox

Target filling and layering methods must be scaled to high throughputs

The first full target supply system is

at OMEGA 4 filled/layered

targets/day

36 " I.D. X 40 " Tall, 8 trays,290,000 targets

Pressure cell with traysCOLD HELIUM

FLUIDIZED BED WITH

GOLD PLATED (IR

REFLECTING) INNER WALL

INJECT IR

Fluidized BedConcept for

Capsule Layering

ASSEMBLED HOHLRAUMS ARE STAGED IN VERTICAL TUBES WITH PRECISE TEMPERATURE CONTROL

Tube Layering Concept for Hohlraums

.... Basic premise: develop processes so small crews can operate

Anticipated target injection and tracking costs are low

HYLIFE-II power plant concept showing basic injector components

SpringTarget

Target injection critical issues1) Withstand acceleration during injection2) Survive thermal environment3) Accuracy and repeatability, tracking

Must supply about 500, 000 targets per day for a 1000 MW(e) power plant1) Injection placement accuracy to ±5 mm2) Indirect/direct drive tracking and beam steering to less than ±200/20 m

Direct drive target sabot

.... Additional work will be needed to define injection costs

Major steps to reduce IFE target manufacturing costs

Current Cost ProductionCost Item Per Shell ($) Cost ($) CommentTotal Cost ~$2752 $0.083 Per "shot-quality" target

EliminateFOAK (R&D) $1200 ~0 Produce a fixed target design

ReduceCharacterization- Support R&D 225 ~0 No R&D support- Pedigree 1200 <$0.05 Process control

ManufacturingCost $0.013-Labor (yield, batch size) 125-Materials Cost 2 $0.02

The vast majority of the cost reductions come from

eliminating R&D and the QC “pedigree” for each target.

.... Additional work will be needed to define filling, layering, and injection costs

Summary and conclusionsCurrent experimental-target fabrication costs need to be reduced about four orders of magnitude for economical IFE power production

Cost reductions of 104 or more from early fabrication to mass-production are common in high-tech industries

Reductions from the current cost will be achieved by: - eliminating first-of-a-kind and development efforts inherent in today's

experimental-targets- reducing the cost of QC by implementing statistical process control and

automating inspection processes- developing equipment and processes for large batch sizes and/or continuous

production- conducting the development programs necessary to achieve high product yields

.... A significant development program is needed to provide low-cost mass-production of IFE targets