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HEAVY-METAL NUCLEAR POWER: Could Reactors Burn Radioactive Waste to Produce Electric

Power and Hydrogen? Eric P. Loewen, Ph.D.

President, American Nuclear Society

August 24, 2011 Presentation to Colorado School of Mines

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About ANS

Professional organization of engineers and scientists devoted to the applications of nuclear science and technology

11,500 members come from diverse technical backgrounds

Dedicated to improving the lives of the world community within government, academia, research laboratories and

private industry

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Times Square, 2010

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Careful What You Do Your R&D On

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Our Journey Together

Heavy Metal Fast Reactor Physics LBE Corrosion Issues Polonium Issues Basic Reactor Design Four Metal Reactor Missions

Once Through Fertile-Free TRU Burner Fertile-Free MA Burner Fertile TRU Burner

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Heavy Metal Fast Reactor

Physics 7

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The Waste

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Spent Reactor Fuel

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Metal Cooled Reactors: A Fast History

Soviets heavy-metal program began in the 50s

Culminated with a reactor in an attack submarine

Seeking to apply military technology to commercial use

Russia’s experience sparked interest here for US metal cooled reactors

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Fast Reactors:

Produce hard neutrons that maintain a high velocity as they strike lead

High velocity neutrons explode fissile atoms into two fragments

Transmutation = large radioactive atomic species converted into a smaller, radioactive atom

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Differences With Fast Reactors

Operate at higher temperatures Neutrons are traveling at relatively high

speeds Reactor can consume its waste and waste

from other reactors Addresses the waste problem It’s a sustainable energy source

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Fission Energy: Fast and Slow Neutrons

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Spent Fuel & Transmutation

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Neutron Speeds

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Neutron Physics: Cross Sections

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0.2

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Fiss

ion

s p

er

Ab

sorp

tio

n

Actinide

Thermal

Fast

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LBE Corrosion Issues

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Dissolution Precipitation Heat

out

Heat in

Collaboration

Pipe wall Hot Cold

Pb flow + O2

Ni

Fe

CR

PbO

Ni

Fe

CR

Oxide layer

INEEL - Commercial materials

- Chemical composition

MIT - Advanced materials

- Development of materials

Mass Transfer Corrosion

Oxygen

Potential

Surface morphology

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INEEL Testing Apparatus

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Corrosion Control Requires Control Requires O2 Control

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316 SS Cross Section Exp: 500°C, 100 h

Lead

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As & Sb

Oxidation Reduction FeAs

FeAs

Pb

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HT9 SEM

Results

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Polonium Issue

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The Polonium Issue in LBE-Cooled Reactors

Po Production PbPoBinBi

daystdayst

206

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210

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210209

2/12/1

Po chemical form in LBE: 99.8% PbPo, 0.2% elementary Po

Po

Extraction

CORE

Po Release

- PbPo evaporation

- PbPo+H2OH2Po+PbO

Accidental Pb-Bi spill.

Po Deposition

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Alkaline Experimental Steps

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Two Different NaOH Sampling Methods

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Basic Reactor Design

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Basic Reactor Design

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The Heavy Metal Reactor

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LBE Reactors

Lead-bismuth eutectic safety advantages: Higher specific heat Higher density Lower neutron absorption Higher scattering High boiling point

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LBE Reactors

Heavy-metal liquid’s high boiling point, heat of vaporization, reduces the possibility of coolant loss and catastrophic core melting Lead remains liquid and only boils at 1,750° C Lead-cooled system can be operated at atmospheric pressures preventing common light-water reactor accidents

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Additional LBE Safety Features:

Passive residual heat-removal system limits maximum temperature to 600 degrees below boiling point

Nuclear fuel is highly soluble in the coolant, density higher than nuclear fuel

Can naturally shut down fission reactions Reactor might operate totally on natural

circulation

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Heavy Metal Reactor Missions

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Four Heavy Metal Reactors

1. Once through 2. Fertile-Free TRU Burner 3. Fertile-Free MA Burner 4. Fertile TRU Burner

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#1 Once Through

Cheaper electricity Has harder neutron spectrum with in-

core breeding and excellent safety characteristics

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Once-Through Scheme

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Burning Waste: Fertile vs. Non-Fertile

Traditional reactors have fertile material Thorium becomes uranium Uranium becomes plutonium

Replacing fertile material with waste changes the reactor’s performance

Control is more difficult, economic penalties

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#2: Fertile-Free Transuranics Burner

Achieve maximum burning of transuranic

waste Recycling usually done in 18-month

increments but can be extended Security advantage: virtually impossible

to produce fissile material for weapons

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#2: Fertile-Free Reactors (con’t.)

Most promising for burning old and existing radioactive waste:

700-megawatt-thermal modular reactor could burn 0.2 MT TRU/yr

Represents 2/3 annual output of a large 3,000 megawatt light-water reactor How many to break down existing waste? Need 35-50 small reactors running for 40

years

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#2: Fertile-Free Reactors, (con’t.)

Multi-pass: 99.9% reduction in long-lived

transuranics-waste inventory Would reduce the radiotoxicity of

consolidated final waste stream to comparable amount of uranium ore would emit in 300 – 600 years

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#3: Fertile-Free Minor Transuranics Burner

Fertile-Free Minor Transuranics Burner Designed to maximize the rate minor

transuranics are destroyed without destroying plutonium

Plutonium is separated and burned in light water reactor

Minor transuranics burned in heavy reactor

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#3: Fertile-Free Minor Transuranics Burner (con’t.)

Fertile-Free Minor Transuranics Burner, con’t. Fewer heavy-metal reactors would be

needed 0.8 percent plutonium, 0.1 percent minor

transuranics in light water reactor spent fuel

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#4: Fertile TRU Burner

To produce economical electricity and burn transuranics

Would employ thorium Creates supplemental fuel, improves reactor

performance and stability Thorium is three-times more abundant

than uranium Thorium takes up more room where

transuranics reside so more reactors are needed

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Reduce, Reuse, Recycle -- Safely

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Multi-Cycle Scheme

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What Now?

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Join ANS!

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Thank You!

For more information contact the ANS Public Outreach department at 800-323-3044 or visit

ww.ans.org. 48

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Information Source

This presentation is derived from an ANS Special Issue of Nuclear Technology, September, 2004

and

“Heavy-Metal Nuclear Power: Could an unconventional

coolant enable reactors to burn radioactive waste and produce both electric power and hydrogen? American Scientist, Volume

92, 2004 November-December

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