Spent Fuel Revisited

Tad Cleavesthollandc@hotmail.com

Energy LawApril 26, 2006

Overview

World Demand for Electricity is Growing Nuclear Energy & Fuel Cycle Safety Environment Conclusions

Demand for Electricity is Growing Rapidly

Electricity Consumption will almost double in next two decades. Industrialization Population Expansion

Demand For “Energy” Growing

Oil – Up 50% Coal – Up 57% Natural Gas – Up 140%

Fossil Fuels are Kings of Electricity

Fossil Fuel: ~66% Nuclear: ~17% Hydro: ~17% Other: ~2%

Fuel Supplies are Dwindling

Inexpensive Petroleum Supply measured in terms of decades…

Natural Gas measured in decades to maybe a century…

Coal measured in centuries…

Inexpensive Uranium deposits measured in decades to maybe a century…

More Efficient Nuclear Fuel Cycle

Extend Present Reserves

Lower Carbon Emissions

General Information ~20 % of U.S. electrical

generation

50 % of Illinois electrical generation

Same principles as coal or natural gas plants

103 U.S. nuclear power plants 440 global power plants

All but 2 are Thermal Light Water Reactors

Nuclear Fuel

Thermal Pressurized Water Reactors are most common type of reactor

Start with enriched uranium In nature:

99.3% U238 “Fissionable” and “Fertile” .7% U235 “Fissile”

Enriched Uranium: ~5% U235

Pu239 by-product of neutron absorption. “Fissile”

10

Source of Heat: A Possible Reaction in a Reactor

n + 235U 141Ba + 92Kr + 3n

Masses: U = 235.043 924u

Ba = 140.909 241

Kr = 91.905 038

n = 1.008 665

236.053u 235.84u

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Mass Difference = E

236.053u 235.84u is a mass difference of 0.2123u

E = mc2

E = 0.2123 x c2

Yields ~ 197.757 MeV energy

Per atom, this is about 5,000,000 times!! the energy released in combustion of oxygen.

The Goal: Controlled Chain Reaction

Two Chain Reactions...Controlled Chain Reaction: Electricity

Uncontrolled Chain Reaction: Bad News…

Spent Fuel: Radioactive “Waste”

3 Classes of “Waste” Material1. Fission Products (5%)

– Mostly Cesium 137 and Strontium 90– Dangerous ~300 years

2. Uranium 238 (~94%)

3. Transuranics (1%)– Everything “heavier” than Uranium– Dangerous, long-lived isotopes.– 10,000+ year half-lives

Transuranics…

Once-Through Fuel Cycle

All of this material is considered “waste” Inefficient:

Only 5% of potentially fissionable atoms have been used!!

Only 10% of mined uranium is converted into fuel in enrichment process.

Bottom Line: Less that 1% of the ore’s total energy is

used to generate energy in once-through regime!

This “Waste” Can Still Power Reactors

Needs to be “Reprocessed” First France, Japan, Russia, and UK reprocess Jimmy Carter banned civilian reprocessing

in US in 1977Fear of weapons-grade Pu239 proliferation

Two types of reprocessing: PUREX and Pyro

PUREX

Plutonium URanium ExtractionDevised for weapons manufactureSynonymous with “reprocessing” when

reprocessing was banned in 1970s Extracts pure Pu239 from spent fuel

Pu239 is the isotope of Pu used for atomic weapons

PUREX for Electricity

Pu239 is used to power reactors in the form of metal oxides (MOX).Can be burned in thermal reactors

Total Energy Usage:6% of original reactor fuel energy is used 94% still unharnessedMassive amounts of waste left over.

The Pyrometallurgical Process

“Pyro” collects virtually all of the transuranics and much of the uranium Few transuranics in the

final waste stream

Pure Pu239 is never isolated

Based on electroplating

Problems with Pyro…

Basic principles have been demonstrated, but the technology is not ready for immediate commercial use.

The fuel extracted can be burned in Fast Reactors only.NOT usable in Thermal Light Water ReactorsOnly 2 Fast Reactors operating in the world…

“Fast” Refers to Neutron “Speed”

Light Water Reactors take advantage of “Slow,” thermal neutrons These neutrons can easily split unstable, fissile

atoms: Pu239, U235

Sometimes split other atoms: U238

High “capture cross section” Fast Neutrons

Have higher “fission cross section” Can split all actinides

Fission vs. Capture in PWR and Fast Reactor

Fast Reactor Designs

Energy Efficiency of Fast Reactors

Can recover 99% of energy in spent thermal reactor fuel

After thermal reactor fuel runs out, Fast reactors can burn depleted uranium.Depleted = Non-enriched U238

99% energy recovery MUCH GREATER YIELD

Fast Reactors In Operation

Not a new technology… Los Alamos, NM, 1946

Naval Applications Especially Soviet

US, France, Russia, and Japan have built FRs India is pursuing FRs

Only 2 in civilian operation France & Russia

Why are FRs not in use?

“Reprocessing” is a bad word. Out-dated bias

“Pyro” process also untested commercially No infrastructure at this point

Uranium is inexpensive Fuel is not significant portion of cost ~5% of total cost of nuclear generation is fuel Compared to ~75%-80% of cost of natural gas

generation. Easier keep loading the proven thermal reactors with

cheap uranium…

Greater Safety Issues?

No Safer than light water reactors

Operate at atmospheric pressureUse liquid metal coolant instead of waterHave more passive safety features

Strong track recordThe problems encountered (e.g. Monju, Japan)

have resulted in little more than big messes…No radiation released.

No Plutonium Proliferation

Fast Reactors efficiently consume plutonium.Light Water reactors are plutonium breeders

The only waste products are the “fission products”Nuclear Ash

No “Plutonium Mines”

Bad Presentation Timing…Chernobyl Disaster – 20 Years Ago, TODAY!

Cause Unauthorized testing that caused

the reactor to lose control Reactor lost control

Effect Steam explosion blew the top

containment off the reactor core Large contamination release

across a 20 square mile area LIFE: 48 deaths directly

Shady records… Thousand exposed to elevated

radiation

Other Energy Related Accidents

China Coal Mining Industry (11/05) Qitahe, China: 171 workers were killed

5,491 coal workers deaths in 2005 Unofficial statistics closer to 20,000 deaths…

2,900 reported accidents

Environmentally Superior

Emission free The only waste produced by FRs with this fuel

cycle is nuclear ash. 1,000 MWe FR would produce 1 ton of fission

products. (1% the “waste” of light water reactor) Only very small amounts of long-lived transuranics

FRs can burn the 30+ years-worth of stored spent fuel.

No need for long-term storage (Yucca Mountain)

Environmental Cost of Hydro

Before & After: Grand Coulee Dam

Everything has a price...

Conclusions

Need more researchPyro and FRs in large-scale production

Several Decades Required Huge upside

Produce electricity indefinitelyTransmutate nuclear wastePrice StabilityEnvironmentally sound

For more information: Decide the Nuclear Issues for Yourself Nuclear need not be

Unclear by J.A.L Robertson http://www.magma.ca/~jalrober/Decide.htm

The New Economics of Nuclear Power, World Nuclear Association, http://www.uic.com.au/neweconomics.pdf

The Path to Sustainable Nuclear Energy Basic and Applied Research Opportunities for Advanced Fuel Cycles, 2005, http://www.sc.doe.gov/bes/reports/files/PSNE_rpt.pdf

http://www.energy.gov/engine/content.do?BT_CODE=NUCLEAR

Smarter Use of Nuclear Waste by William Hannum

Questions??