Presentation on energy iter2017 january

“When we look up at night and view the stars, everything we see is shinning because of distant nuclear fusion ’’ -Carl Sagan

American astronomer cosmologist and astrophysicist

(1934-1996)

NUCLEAR FUSIONInternational Thermonuclear Experimental Reactor (ITER)

DEPARTMENT OF MATERIAL SCIENCE AND ENGINEERING

AFRICAN UNIVERSITY OF SCIENCE AND TECHNOLOGY, ABUJA

Cooper Kollie LACKAY

40447

Lecturer: Prof. Esidor NTSOENZOK JANUARY 26, 2017

TABLE OF CONTENTS

INTRODUCTION

FUNDAMENTALS OF THE PRODUCTION OF ENERGY BY FUSION

DESCRIPTION OF ITER

• State of art of ITER• The Tokamak

CHALLENGES AND SOLUTIONS• Material Issues• Proposed Solutions

FUTURE OF ITER

RECOMMENDATIONS

CONCLUSION

REFERENCES3

INTRODUCTION

The first fusion experiments in the 1930s, fusion physics laboratories were established in nearly every industrialized nation.

By the mid-1950s "fusion machines" were operating in the Soviet Union, the United Kingdom, the United States, France, Germany and Japan.

A major breakthrough occurred in 1968 in the Soviet Union. The Soviet machine was a doughnut-shaped magnetic

confinement device called a tokamak. The world's first tokamak device: the Russian T1 Tokamak at the Kurchatov Institute in Moscow. It was the first device to use a stainless steel liner within a copper vacuum chamber(Ostwald, 1993)

4

INTRODUCTION

ITER (International Thermonuclear Experimental Reactor) is the world's largest experimental nuclear fusion reactor which aim is to deliver nuclear fusion on a commercial scale, offering safe, limitless and environmentally responsible energy.

The particular magnetic configuration chosen for ITER is the Tokamak.

This choice was driven by the vast, successful experience with tokamak experiments around the world over the last forty years.

5

FUNDAMENTALS OF THE PRODUCTION OF ENERGY BY FUSION

Fusion is the process that powers the sun and the stars.

Deuterium is plentifully available in ordinary water.

Tritium can be produced by combining the fusion neutron with the abundant light metal lithium.

Fig:1. NUCLEAR-FUSION REACTION (Ostwald, 1993)

6

FUNDAMENTALS OF THE PRODUCTION OF ENERGY BY FUSION

First two hydrogen nuclei 1H+ (protons) fuse into a deuterium nucleus 2H+, releasing a positron e+ and an electron neutrino νe as one proton changes into a neutron:

The resulting deuterium nucleus reacts with another proton, resulting in the light helium isotope 3He2+ and a gamma ray photon  :

In the reaction of the pp I branch helium-4 comes from fusing two of the helium-3 nuclei produced:

The fusion of a deuterium and a tritium nucleus creates an alpha particle, a neutron and 17.6 MeV energy.

7

DESCRIPTION OF ITER MAIN PARAMETERS

Plasma Major Radius 6.2m Toroidal Field on Axis 5.3TPlasma Minor Radius 2.0m Fusion Power 500MWPlasma Volume 840m3 Burn Flat Top >400sPlasma Current 15.0MA Power Amplification >10x

Fig: 2.Schematic diagram of the components of the ITER tokamak– © ITER Organization 8

DESCRIPTION OF ITER

STATE OF ART OF ITER

Fig 3:ITER VIEW 9

DESCRIPTION OF ITER

STATE OF ART OF ITER

Fig 4: The decision to site the ITER Project in southern France was made by the ITER Members in June 2005.

10

The Tokamak

DESCRIPTION OF ITER

Tokamak is a toroidal apparatus for producing controlled fusion reactions in hot plasma.

The tokamak is a nearly axisymmetric torus The principal non-symmetric aspect is the set of

discrete magnetic field coils which generate the dominant toroidal magnetic field

Fig 5: Tokamak 11

CHALLENGES AND SOLUTIONS

CHALLENGESIMPURITY DESORPTION Light impurities like C, N, H2O, and O are frequently adsorbed

on chamber walls. Surface impurities come from residual gases present in the chamber, redeposition of sputtered atoms, and segregation of the surface of impurities present in the wall material.

BLISTERING Blistering can be a source of plasma contamination when the

heat flux is high, shortening the lifetime of plasma facing components. Blistering can occur when the critical helium concentration occurs inside the metal before it occurs at the surface. Blistering and flaking may be a problem in cases where sputtering rates are low, most of the alphas are at 3.5MeV, and the alpha flux is high.

AUSTENITE Austenitic stainless steel currently used.

12

CHALLENGES AND SOLUTIONSOLUTIONS

The position solution to impurity desorption is to bake out the vacuum chamber which will helps to clean most of the adsorbed mono-layers of light impurities. Plasma discharges are often repeated for days on large experiments to clean the chamber walls. Plasma particles and photons striking the walls may stimulate desorption to remove impurities.

BLISTERING: If the alpha flux is low, if the alphas are more uniformly distributed in energy, or if sputtering rates are high, then, blistering is not likely to be a serious problem.

For austenitic stainless steel, the inner surface should be replace every few years

13

FUTURE OF ITER EXPERIMENT

The ITER experiment’s baseline mode of operation targets of the thermonuclear gain parameter Q (Pfus/Pin)= 10 with Pfus= 500 MW and a pulse length of about 400 s .

An extended mode of operation at Q = 5 (Pfus = 300 MW) with a pulse length of 1000s is also planned.

ITER’s principal parameters are largely determined by these objectives and a handful of relations derived from engineering requirements and the tokamak database. Those parameters are R = 6.2m, a = 2.0m, Ip = 15MA, and BT (magnetic flux density)= 5.3T. The total plasma volume is about 850 m3; the energy in the toroidal field magnets at full strength is about 41 GJ.

14

FUTURE OF ITER

The experimental fusion reactor, known as ITER, will bring us closer to:

Harnessing the power of a clean, safe and inexhaustible source of energy

No greenhouse gases Suitable for large scale power production Relatively small amounts of radioactive waste on Relatively short time scales (<100 years) No transport of radioactive material No possibility for runaway reaction

These will also serve as great opportunities for research institutions as well as for industry.

There is therefore a brighter future for ITER.

15

RECOMMENDATIONS

Environmental SafetyThe environment should be well secured and guided against the waste or nuclear materials/ radiation that might be generated from the reactor.

FundingGovernment, private companies, and individuals should not stop funding the project, as funding is contingent on continued and sustained progress on the project.

Security There should be increased transparency of the ITER project risk management process.

16

CONCLUSION

ITER will be the essential reactor needed in fusion research towards an energy source.

After the completion of the engineering design activities, technical preparations are well advanced to turn the design of ITER into technical reality.

The ITER project offers a wide variety of fusion development activities for the worldwide scientific community.

During operation, scientists will participate remotely in experiments (e.g., operating diagnostics, analysing data, making proposals for the experimental programme) from many locations in the world.

17

REFERENCES

C. L. Smith, The fast track to fusion power (2004), presented at the 20th IAEA Fusion Energy Conference, Vilamoura, Portugal, November 1 – 6, 2004.

International Fusion Research Council, Nucl. Fusion 45, A1–A28 (2005).

R. H. Socolow, and S. W. Pacala, Sci. Am. 295, 50–57 (2006).

I. T. B. Editors, Iter technical basis, Tech. Rep. ITER EDA Documentation Series No. 24, IAEA, Vienna (2002); see also http://www.iter.org.

ITER Physics Basis Editors, Nucl. Fusion 39, 2137–2638 (1999).

D. Reiter, et al., “The role of atomic and molecular processes in magnetic fusion plasmas,” in Atomic and Molecular Data and Their Applications, AIP Conf. Proc. 771, American Institute of Physics,2005, New York. 18