Reactors Daniel Cooper Department of Materials Science and - - PowerPoint PPT Presentation

Daniel Cooper

Department of Materials Science and Engineering The University of Sheffield

Supervisors: Mark Rainforth

(University of Sheffield, Department of Materials Science and Engineering)

Mark Ogden

(University of Sheffield, Department of Chemical Engineering)

Karl Whittle

(University of Liverpool, Centre for Materials and Structures)

Tim Abram

(University of Manchester, School of Mechanical, Aerospace and Civil Engineering)

Daniel Cooper

Department of Materials Science and Engineering The University of Sheffield

Supervisors: Mark Rainforth

(University of Sheffield, Department of Materials Science and Engineering)

Mark Ogden

(University of Sheffield, Department of Chemical Engineering)

Tim Abram

(University of Manchester, School of Mechanical, Aerospace and Civil Engineering)

Karl Whittle

(University of Liverpool, Centre for Materials and Structures)

Doctoral Academy Conference 2016, Sheffield – 21st June 2016

Materials for Molten Salt Nuclear Reactors

Contents

• The need for nuclear power
• How can we improve nuclear power?
• What is a molten salt nuclear reactor?
• Materials challenges
• Corrosion of materials
• What do I do?

2

Correlation of GDP per capita and power consumption

3 David J. C. MacKay, Sustainable Energy – Without the Hot Air, 2008, p.231

Worldwide Greenhouse Gas Emissions

4 David J. C. MacKay, Sustainable Energy – Without the Hot Air, 2008, p.12

Why Nuclear Power?

5

One uranium fuel pellet in today’s reactors provides the same energy as about one ton of coal

Higher energy density ⇒ less land & less waste

“But Dan, what about nuclear waste?”

The really bad waste, the stuff that lasts thousands of years, from all past and future nuclear power in the UK is enough to fill just 95 double decker buses…

6 NDA, DECC, 2013 UK Radioactive Waste Inventory: Waste Quantities from all Sources, 2013

Current Nuclear Reactors – Water-cooled

7

Disadvantages of Water-cooled Reactors

8 Top Left: EPA/TEPCO. Bottom Right: Olander, Journal of Nuclear Materials, 389, 1-22 (2009)

Right: Fuel rods, before and after Solid fuel ⇒ premature removal, lower fuel use and added cost Pressurisation ⇒ Safety risk and added cost Left: Fukushima Dai-ichi underwent rapid pressure loss as a result

• f a hydrogen explosion.

What should we change?

9

Design the reactor so that in an accident it shuts down naturally

This will make it cheaper and safer

Use a liquid fuel to avoid the problems with solid fuel

This will allow the fuel to stay in the reactor longer

Design our reactors so that they can utilise waste material as fuel

Molten Salt as a Coolant

10

Change coolant from water to molten salt – no need to pressurise

H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O H2O

Air Solution

Na+ Na+ Cl- Cl- Na+ Na+ Cl- Na+ Na+ Cl- Na+ Cl- Cl- Cl- Cl-

Weaker Hydrogen Bonds Stronger Ionic Bonds

GIF-002-00, “A Technology Roadmap for Generation IV Nuclear Energy Systems”, December 2002.

Molten Salt Reactors

11

History of molten salt reactors

Change of policies, funding lost because other projects were further developed

12

Left: Proving the Principle by Stacy, Susan M., U.S. Department of Energy, Idaho Operations Office. ISBN 0-16-059185-6, chapter 13. Right: ORNL Photo 67051-64.

Aircraft Reactor Experiment (ARE), 1954 Molten Salt Reactor Experiment (MSRE), 1965-1969

Materials Requirements

13 Ignatiev and Surenkov, “Material Performance in Molten Salts”, Comprehensive Nuclear Materials, 2012, pp. 221-250.

Materials requirements

High melting point High- temperature mechanical strength Corrosion resistant Resistant to radiation damage

Which materials?

14

Plastic?

✗High melting point ✗ Mechanical properties ✗Radiation damage resistant ~ Corrosion Resistant

Glass?

~ High melting point ✗ Mechanical properties ✓ Radiation damage resistant ✓ Corrosion Resistant

Ceramic?

✓ High melting point ~ Mechanical properties ✓ Radiation damage resistant ✓ Corrosion Resistant

Metal?

✓ High melting point ✓ Mechanical properties ✓ Radiation damage resistant ✓ Corrosion Resistant

Basics of Corrosion

15

• E. McCafferty, Introduction to Corrosion Science, 2010.

Corrosion in Molten Salts

• Oxygen and water removed to prevent corrosion
• Use argon gas to maintain pressure, chemically

unreactive

• Still get corrosion driven by fuel, waste and salt

movement

16

𝑃2(𝑕) + 4𝑓−⇌2𝑃2− 𝐼2𝑃 + 2𝑌−⇌𝑃2− + 2𝐼𝑌 𝐼2𝑃 + 𝑌−⇌𝑃𝐼− + 𝐼𝑌

What do I do?

• 2. Prepare

samples of materials

• 3. Expose to

molten salts

• 4. Create

electrical circuits to understand reactions

• 5. Examine

materials after corrosion

• 1. Use

understanding

• f properties

to drive material choice

17

• Mechanical alloying
• Spark plasma

sintering

• Micropreparation

Metals, Binary Carbides and Mn+1AXn Phases

18

Transition Metal

e.g. Titanium

Metal Carbide

e.g. Titanium Carbide

Mn+1AXn Phase

e.g. Titanium Aluminium Carbide

Ceramic Metallic Strong Ductile High temperature

• xidation resistant

Machinable High temperature corrosion resistant Thermally and electrically conductive Creep resistant Thermal shock resistant Mn+1AXn Phases – Structure and Properties

19 Whittle et al., 2010, Acta Mater., 58, 13, 4362.

n = 1 ⇒ 211 n = 2 ⇒ 312 n = 3 ⇒ 413

What is the impact of this research?

20

Effect Application My Work

Chemical properties of MAX phases Molten Salt Nuclear Reactors Cheaper, more efficient nuclear power High- temperature chemical processing Longer material lifetime, reduced cost Jet Turbine Blades Improved fuel efficiency for air travel