Introduction

Outline Issues for Calculations for 1. Fusion development ITER Fusion Reactor 2. Issues for neutronics calculations 3. Risø DTU reasons for participating in ITER Erik Nonbøl and Bent Lauritzen 4. Example of calculation on ITER-CTS Risø DTU, National Laboratory for Sustainable Energy diagnostics system Roskilde, Denmark

NSFS meeting Ålesund, Norway May 26-30, 2008

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Fusion development ITER to be build in France

ITER, International Thermonuclear Experimental Reactor

ITER TORE SUPRA Fusion CADARACHE at Research Aix-en Provence Center in France

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Fusion process Development of fusion designs The process involved is the following:

D + T → He4 + n + 17,6 MeV

14.1 MeV

3.5 MeV

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1 JET Major progress

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Next steps for fusion Design principle for a fusion plant

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Issues for fusion vc. fission neutronics calc.

• in fission is determined by a criticality

blanket modules iteration TF-magnet • Neutron source in fusion is prescribed by the test blanket port conditions – no iteration is needed • Different neutron energy spectra plasma chamber cryostat • Fission peak 1-2 MeV • Fusion peak 14 Mev divertor

vacuum vessel

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2 Neutron flux spectra: fusion vs. fission Fusion process and tritium breeding

1016

4 HFR Petten D + T → He + n + 17.6 MeV 15 ] 10 Demo first wall -1 u -1 s -2 6Li + n → T + 4He + 4.86 MeV 1014 7Li + n → T + 4He + n - 2.5 MeV

1013 9Be + n → 2n + 2 4He 1012 Neutron flux density [cm

1011 101 102 103 104 105 106 107 Neutron energy [eV]

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Neutronics calculations Neutronics calculations

Fusion Reactor Design Issues QA/QC •Blanket • Tritium breeding, power generation, (shielding) • Fusion Reactor Design relies on data provided by nuclear ⇒ assure tritium self-sufficiency, provide nuclear heating data for thermal- design calculations hydraulic layout • Qualified computational simulations are required • Shield • Attenuate radiation to tolerable level ⇒ Appropriate computational methods, tools (codes) and ⇒ assure sufficient protection of super-conducting magnet data (nuclear cross-sections) ⇒ avoid structural damage, helium gas production in steel structure ⇒ Validation • Safety & Environment, Maintenance • Material activation • Qualification through integral benchmark experiments. ⇒ minimise activation inventory with regard to short-term and long-term hazard potential ⇒ maintenance service during reactor shutdown (dose level)

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Risø DTU reasons for participating in ITER Monte Carlo calculations

• Experience in calculation of neutron and gamma fluxes and in fission reactors by means of the Monte • A simplified ITER 40 degree geometry input model for MCNP-5 Carlo code MCNP has been developed (about 300 cells) • Detailed geometric description of the CTS diagnostics system • Validation calculations performed for Forsmark Plant • Well suited for parametric studies – short CPU time

• Local Association Euratom/Risø DTU Plasma group, need for • The input model has been benchmarked against the (20 in-house neutronics calculation capabilities for designing the degrees) ITER FEAT reference model (about 3000 cells) Collective Thomson Scattering (CTS) diagnostics system

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3 Geometry of simple model vs. ITER FEAT model Risø’s CTS system Simple model ITER FEAT model • CTS: Collective Thomson Scattering • diagnostic of fast ions • alterations to inboard blanket • Neutronics: • Temperature increase in the TF coil magnets • Material damages due to fast

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Mirror 1 and Mirror 2 Blanket module

Fund. Wave- guides

Mirror #1 Blanket Module key Beam

Mirror #2

Horns Cooling manifold

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Blanket Cut-out CTS calculation with mirror cavity and slot

TF coil

Blanket #4

Slot + mirror cavity Vertical Gap = 10 mm Spacer (in yellow )= 8 mm

Mirror +cavity

Blanket #3

Blanket Cut-out Height = 28 mm Width front = 580 mm Width back = 410 mm Horizontal cross section Vertical cross section

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4 Nuclear heating of TF winding pack Fast neutron flux in TF coil insulator (epoxy)

Nuclear heating of TF winding pack Fast neutron flux (E>0.1 MeV) in TF coil insulator 4.00 1.2x10-4

Design limit = 1.4 x10-4 W/g 1.1x10-4 3.50 ] -4 1.0x10 -1 s

-2 3.00

-5

9.0x10 n cm

10 2.50 8.0x10-5

-5 2.00 7.0x10 Design limit

-5

Heat [W/g] deposition 6.0x10 1.50 Fast neutronflux [10 5.0x10-5 Cavity and slit 1.00 No cavity Cavity and slit -5 4.0x10 No cavity 0.50 3.0x10-5 020406010 30 50 010 204060 30 50 Slit height [mm] Slit height [mm]

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