Going Underground: Safe Disposal of Nuclear Waste

Burton Richter

Pigott Professor in the Physical Sciences, Emeritus

Stanford Energy Seminar

January 23, 2012

Nuclear Energy Issues

• It is too expensive

• It is not safe

• We don’t know what to do with very radioactive spent fuel

Lifecycle Emissions for Various Electricity

Generation Technologies

Comparison of Life Cycle Emissions in Metric Tonnes of CO2e per GW-hour for various modes of

Electricity Production; P.J. Meier, Life-Cycle Assessment of electricity Generation Systems with

Applications for Climate Change Policy Analysis,

Ph.D. dissertation, University of Wisconsin (2002); S. White, Emissions form Helium-3, Fission and Wind

Electrical Power plants, Ph.D. Dissertation, University of Wisconsin (1998); M. K. Mann and P. L. Spath,

Life Cycle Assessment of a Biomass Gasification Combined-Cycle System,

(1997), www.nrel.gov/docs/legosti/fy98/23076.pdf (ref 33).

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4

Spent Fuel – Love It or Hate It We Have It:

What to Do With It Is the Issue

• We have about 60,000 tonnes now

• Current reactors will produce 60,000 tonnes more over their lifetimes

• Disposal costs are built into nuclear electricity costs at 0.1 cent/KW-hr ($20 B in fund now)

The Nuclear Fuel Cycle – Today's LWRs

• Natural uranium has about 0.7% U-235

• Enrichment increases U-235 to about 4.5%

• Fuel spends about 4 years in a reactor

• On removal used fuel spends about 4 years in a water pool

• Storage can then be in dry casks

• Long term isolation from the environment is the issue

Component Uranium Fission

Fragments

Long-Lived

Component

Percent Of Total 95 4 1

Radioactivity Negligible Intense Medium

Untreated Required

Isolation Time

(years)

0 500 1,000,000

Elements of Spent Fuel

Radioactivity of Used Fuel

Rules of the Game

• Spent reactor fuel must be safely isolated for as long as it is dangerous

• Must be retrievable for 50 years after emplacement

• Required time for untreated spent fuel is hundreds of thousands of years

• It is known to be possible

• The natural reactor at Oklo in Gabon, Africa started 1.7 billion years ago, burned for hundreds of thousands of years and its long lived radioactive elements have only moved a short distance

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A Bit of History

• 1982 – Congress says spent fuel disposal is a federal responsibility, sets an amount utilities have to pay, tells DOE to find a site

• 1987 DOE comes up with 3 (Texas, Washington state, and Nevada)

• Texas and Washington have lots of political muscle; Nevada (Yucca Mt.) gets it without any say in the matter

• Nevada has fought it ever since while DOE did 20 years of R&D at a cost of $10 billion and submitted an application for construction approval to the NRC in 2008

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Current Situation

• Yucca Mountain was supposed to open in 1998

• Utilities have paid into the waste fund; have contacts with DOE; courts have said DOE is in default and has to pay for temporary storage at reactor sites

• No problem (except money) in storing spent fuel at reactors

• The Obama administration withdraws the application to license Yucca Mt. in 2009 and creates the blue ribbon commission in 2010 to recommend what to do and how to do it

The Future of Spent Fuel Disposal

• This is a big political component and a smaller technical one

• 1987 – Congress forced repository on Nevada

• Other countries have used a consent-based system (Sweden, Finland, France)

• Blue ribbon commission recommends a consent-based system

• We have a working repository in New Mexico – WIPP (Waste Isolation Pilot Project)

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Radiotoxicity of LWR Spent Fuel

1.E-03

1.E-02

1.E-01

1.E+00

1.E+01

1.E+02

1.E+03

1.E+04

1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

Time, years

Re

lati

ve

CD

Ha

za

rd

Total Actinides

Total FP

Np-237

Pu-239

Pu-240

Am-241

Used Fuel Assembly From a PWR

Yucca Mountain

Yucca Mountain Repository Layout

Sweden’s System

Finland Follows Sweden

France

• Disposal in alkaline clay

• Site selected with local agreement

• Fission fragments an long lived actinides in glass logs

BRC Recommendations www.brc.gov

• Focus on granite clay or salt

• Negotiate an agreement with the state and locality

• Set up a semi-private company to develop and manage the project

• Give the state a large financial incentive

• Take Congress out of the loop on spending from the waste disposal fund

An Alternative for Disposition of Pu And “Minor” Actinides

Nuclear Answer: Use nuclear reactors to

“burn” or reduce inventories of plutonium

and “minor” actinides in MOX or inert matrix

fuels.

Geologic Answer: Geologic disposal of

spent nuclear fuel and/or immobilization of

actinides in durable solids.

24 CISAC February 25th, 2009

An Alternative – Closing the Fuel Cycle

Plutonium recycling

Spent Fuel Direct disposal

Uranium Ore (mine)

Time (years)

P&T of MA

Pu + MA + FP

MA + FP

FP

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(a) Transmutation Schematics with LWR

Recycle

(b) Without LWR Recycle

LWR Reprocessed

Fuel

Separation Plant

Fast System

(one for every 7 - 8 LWRs)

Plutonium “MOX” fuel U&FF

Separation Plant

U&FF Actinides

LWR

Fast System

Separation Plant

U&FF Actinides

References

• BRC home page: www.brc.gov

• BRC Disposal Subcommittee

• http://www.brc.gov/sites/default/files/documents/draft_disposal_report_06-01-11.pdf

•Sweden’s Repository

•http://www.skb.se/Templates/Standard____24109.aspx

BACKUP

Material Approximate

Quantity

(metric tons)

Number of sites

Total

commercial

spent fuel

storage

54,000 65 nuclear plant sites with 103 operating reactors

9 nuclear plant sites with no operating reactors

1 commercial interim storage site (Morris in Illinois)

2 DOE sites (Ft. St. Vrain in Colorado and Idaho

National Laboratory)a

Pool storage 47,000 65 operating sites

1 centralized site (Morris in Illinois)

9 nuclear plant sites with no operating reactors

Cask storage 7,000 35 at nuclear plant sites

2 DOE sites (Ft. St. Vrain in Colorado and Idaho

National Laboratory) a

US commercial spent fuel quantities and storage

locations in 2005

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Nuclear Fuel Cycles: Geologic Perspective

1,000,000-yr Dose to “Average”

Individual at 20 km

Yucca Mountain Viability Assessment (1998)

Radiotoxicity

Hedin (1997) SKB Report 97-13

Inventory of Decay Heat

Wigeland et al. (2006) Nuclear Technology

Thermal Power of Used Nuclear Fuel 7% of full power at moment after shutdown