assessment of the risks and uncertainties in eliminating nuclear material stockpiles f....

Assessment of the Risks and Uncertainties in Eliminating Nuclear Material Stockpiles

F. STEINHÄUSLERDiv. of Physics and Biophysics

University of SalzburgA 5020 Salzburg

AustriaEmail: friedrich.steinhaeusler@sbg.ac.at

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Topics

1. Source terms and policy issues2. The need to act 3. Technical options4. Security aspects5. Conclusions & recommendations

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1. SOURCE TERMS AND POLICY ISSUES

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SOURCES OF MILITARY HEU and Pu

1. Operational weapons2. Weapon-grade material outside

operational weapons3. Fuel- and thermal-grade Pu in

store

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MILITARY INVENTORY: HEU/Pu(central estimate (t) in 2003, SIPRI)

US: 635/47.5 Russia: 470/100 UK:15/3.2 France: 24/5 China: 20/4 India: “little”/0.31 Pakistan: 0.69/0.005 Israel: ?/0.51 Total: 1 165/160

Production rate: up to 250 kg/GW(th), a

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MILITARY DECLARED SURPLUS: HEU/Pu(central estimate (t) in 2003, SIPRI)

US: 174/52.5 Russia: 500/34 UK:0/4.4

France, China, India, Pakistan, Israel: 0/0

Total: 674/91

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UNDER IAEA SAFEGUARDS: HEU/Pu(central estimate (t) in 2003, SIPRI)

US: 10/2 Russia: 0/0 UK:0/0.1

France, China, India, Pakistan, Israel:0/0

Total: 10/2.1

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DISPOSED: HEU/Pu(central estimate (t) in 2003, SIPRI)

Russia: 96/0

China, France, India, Pakistan,Israel, UK, US: 0/0

Total: 96/0

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CIVILIAN Pu INVENTORY

In spent nuclear fuel Separated in store In fast-reactor fuel cycle In thermal MOX fuel cycle

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Civilian Pu Production Typical annual Pu production rate in

nuclear power reactors: 180 kg /GW(e) Civilian facilities in UK and France can

reprocess fuel elements of all nuclear power plants in EU and Japan

6-10 kg Pu/t of spent fuel

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CIVILIAN OWNERSHIP:HEU/Pu(central estimate (t) in 2003, SIPRI)

US: 5-10/4-5 Russia: …/30.3 UK: ca. 4/59.8 France: ca. 5/40.3 China: …/0 India: …/0.7

Pakistan: …/- Israel: …/- Others: …/59.4 Total:

16-22/195

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Past, Present and Future Pu Stockpiles (central estimates)

257

122

250

180

241

257

0

100

200

300

400

500

t

1990 1999 2010

Weapon Plutonium Separated Civilian Plutonium

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Weapon-usability ofReactor Pu*

- Higher rate of spontaneous fission

- Increased heat production- Higher probability for pre-detonation

explosive yield: 1 to several kt **

* E. Kankeleit, C. Kuppers, U. Imkeller, Report on the weapon-usability of reactor plutonium, IANUS-Arbeitsbericht 1/1989

** Compacting speed of 2-4 km/s

Theft of separated Pu, whether weapons-grade or reactor-grade, is a major

security risk

US National Academy of Sciences,Management and Disposition of Excess Plutonium,

Vol. 1+2, National Academy Press, Washington, D.C.,

1994 and 1995

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2. THE NEED TO ACT

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Inadequate protection

States can no longer claim to be able to protect 100% military nuclear material stockpiles:

US: Force-on-Force exercises (>50% success rate)

FSU: several hundred illicit trafficking incidents since 1991 (at least 27 cases involving weapons-usable fissile material)

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Vulnerability of US DOE Pu Storage Sites*

Interim Pu storage (26 t) for 10 to 20 a Pu stored in 166 facilities at 35 sites** 299

vulnerabilities identified at 13 sites:Inadequate facility conditionsIncomplete safety analysisDegradation of Pu packaging, etc.

*Related to safety, environment and health (Nov. 1994)**Excluding Pantex Plant, Texas

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Imperfect state security networks

States cannot rely exclusively on less than perfect state security networks to protect military and civilian Pu stockpiles:

Corruption of security forces, customs and politicians (www.transparency.org)

Politically/religiously/financially motivated insider threat (extremism, blackmail)

Criminal nuclear supply networks (Pakistan-Malaysia-Libya)

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Personnel performance and misuse of new equipment* at

Russian nuclear facilities

9 sites investigated; three of them had inter alia the following deficiencies:

Gate to central facility left open and unattended

Nuclear material portal monitor not operational

No access control at nuclear material storage site

* Security-related activities, February 2001

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Personnel performance and misuse of new equipment* at

Russian nuclear facilities

No response when metal detector was set off upon entry

Wide spread drug and alcohol related problems

* Security-related activities, February 2001

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Potential for political instability

1. Internal political stability of nuclear weapon states is not guaranteed (Pakistan?)

2. Act of despair: deployment of nuclear weapon as the last resort (Israel?)

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Strong Man Policy

Failed international crisis management, using the Strong Man-Global Policeman Policy, e.g., identification of an external enemy, who will be threatened or contained with a nuclear weapon (DOD Nuclear Posture Review*)

*US Strategic Nuclear Forces (2003): 14 Trident Submarines, 450 Minuteman III ICBM,

66 B-52H bombers, 20 B-2 Stealth bombers

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3. TECHNICAL OPTIONS

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Disposition Programme: Short-term Objectives

Make it harder for individuals to steal the material

Increase the difficulty for rogue nations and terrorists to reuse the material

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Disposition Programme: Long-term Objectives

Prevent contamination of the environment and uncontrolled radiation exposure of man

Signal to others that there is a path to the irreversible reduction of materials stockpiled

Progress towards nuclear arms reduction

Disposition Principle(e.g., for surplus weapon-grade Pu) :

Create a substantial barrier to the recovery of the nuclear

material

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Weapon-grade Pu *

Pu 238: 0.01Pu 239: 93.80Pu 240:

5.80

Pu 241: 0.13Pu 242: 0.02Am 241: 0.22

*Age: 20 years in percent (by weight)

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4 Theoretical Disposition Options, only 2 Realistic Choices

1. Pu dilution in oceans (environmental risk?)

2. Pu transport into space (risk of major accident?)

3. Immobilization of Pu4. Reactor/accelerator

methods using Pu

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17 Evaluation criteria:

1. Operational time scale

2. Material throughput

3. Physical security4. Self-protection 5. Long-term

stability

6. Criticality issues7. Safeguards &

Proliferation resistance

8. Suitability for final depository

9. State of development

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17 Evaluation criteria:

10.Costs for start up11. Costs for routine

operation12. Long-term

neutron stability13. Long-term

chemical durability

14.Environmental impact

15. Local acceptance16. National

acceptance17. International

acceptance

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Example for Open Issues: Proliferation Resistance

Are all the technical methods deployed proliferation resistant?

Does the method allow the pursuit of weapon-relevant technology options?

Is it possible to covertly divert nuclear material?

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Example for Open Issues: Operational time scale

How long does the Pu have to remain in an interim storage area?

When will the industrial-scale version of the disposition method be available?

What is the time period required to totally eliminate Pu?

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Example for Open Issues: Costs

Costs for R & D? Investment costs for constructing

the facilities in US/Russia/EU? Operational costs of facility? Costs for final deposition of resulting

waste products?

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IMMOBILIZATION OF Pu

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Immobilization technologies Direct glass

vitrification Direct ceramic

vitrification Can-in-canister

vitrification

Geologic disposal Electro-

metallurgical treatment

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Direct glass vitrification:Principle

Pu and n-absorbing material*, mixed with molten glass** and high level radwaste

Pu concentration: about 5 to 8% (by weight)

Cooled into large logs (weight: 2 t; height: 3 m)

Large base of experience for industrial scale vitrification (B, F, UK since 1986 or longer)

*e.g., gadolinium ** lanthanide borosilicate

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Direct glass vitrification:Open technical issues

Optimal glass formulation for not immobilized Pu?

Optimal level of solubility of Pu in glass? Prevention of accumulation of critical

mass in processing equipment? Solubility of n absorber potentially higher

than that of Pu, i.e., criticality possible after 10³ years?

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Direct glass vitrification:Open technical issues

Radiation creates helium and oxygen bubbles in glass, increasing the volume: impact of additional cracks?

There is no natural analog of glass containing alpha-emitters: long-term material behavior expose to internal alpha radiation exposure?

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Direct glass vitrification:Open security issues

Is subsequent Pu recovery from glass feasible?

Ground glass, dissolve in nitric acid, remove Pu (PUREX process)

Bench-top solvent removal process extracts about 25% of Pu analog from a glass host

Covert operation requires little additional equipment, no obvious new activity noticeable

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Direct ceramic vitrification:Principle

Pu and n-absorber mixed in ceramic material with high level radwaste

Pu concentraion: <10% (by weight) Radioactive ceramic material placed

inside steel canister Limited large-scale industrial

experience

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Direct ceramic vitrification:Open technical and security issues

Remaining technical and security issues:

Similar to glass vitrification

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Can-in-canister vitrification:Principle

Pu and n-absorbing material mixed with molten glass or ceramic material in steel cans (2.5 kg of Pu/can)

20 stainless steel cans loaded onto a rack within a larger steel canister(3 m long)

Filled with molten, glassified high level radwaste from reprocessing

Cooled (weight: 2 t)

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Can-in-canister vitrification:Open technical and security issues

Technical issues: similar to glass vitrification Security issues:

- 1 spent fuel assembly from BWR/PWR: 1.5/4.2 kg Pu

- 1 canister (20 cans): 12.5 kg Pu*canister contains 400% more Pu than

spent fuel assembly* Equivalent to 3 nuclear weapon pits

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Geologic Disposal:Principle

Deep borehole (several km) Enclose Pu or Pu mixed with high level

radwaste within physical barrier (e.g., glass, ceramics)

Transport enclosed pure Pu or mixture to borehole

Close borehole to (a) minimize direct access; (b) allow defined access at a later stage

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Geologic Disposal:Open technical and security issues

Pu leaching models: Pu solubility is low (10E-8 g/cm³) and glass surface area increases by a factor of 5 due to fracturing

Fracturing due to quenching 10 times higher?* Does crack growth continue throughout lifetime of

glass(water, tectonic stress)? Intentional “Pu Mining” desirable at a later stage? *B. Grambow (Materials Research Soc. Symp. Proc. 333,

167-180 (1994)

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Electrometallurgical treatment:Principle

Pu mixed with monolithic mineral form

Result: glass-bonded zeolite (GBZ)

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Electrometallurgical treatment:Open Technical and Security Issues

Less technically mature than other disposition methods

Several key steps not demonstrated yet at industrial scale

Political concerns due to its similarity to nuclear fuel reprocessing

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REACTOR/ACCELERATOR TECHNOLOGIES USING Pu

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Transmutation:Principle

Origin: in the 1970’s Concept: using high n fluxes, long-

lived isotopes, particularly transuranics, can be transmuted

Product: stable or relatively short-lived radioactive substances

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Transmutation:

Open technical and security issues

High energy linear accelerator needed (p(GeV)

High n flux required (>10E16 n/cm²,s) over Pb or Bi spallation target

High R&D risk: accelerator technology chemical separation methods

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Transmutation:

Open technical and security issues

High energy consumption Low throughput High cost Radioactive waste unavoidable Dual use option (Pu disposition + Tritium

production) Lack of industrial scale demonstration

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Mixed Oxide Fuel (MOX ):Principle

Large industrial facility needed for multi-stage MOX fuel production:

metal Pu converted into Pu oxide powder

grinding & mixing with U sieving/sintering/cutting/polishing

into pellets pellets filled into fuel elements

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Mixed Oxide Fuel (MOX ):Principle

Mixture of natural U with Pu-Oxide, irradiated as fuel in commercial reactors

MOX suitable reactors in Europe: F(20), D(12), CH(3), B(2)

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Mixed Oxide Fuel (MOX ): Open technical and security issues

MOX fuel in fast breeder: 15-35% Pu MOX fuel in LWR: 3-5% Pu 1 GW(e): 25-30 t MOX fuel/a 1 Reactor: only 1.2 to 1.5 t of Pu/a

to meet schedule: full MOX core is needed

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Mixed Oxide Fuel (MOX):Open technical and security issues

“Full core MOX operation”: difficult reactor safety controls safe and secure management of

MOX fuel over period of decades?

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Mixed Oxide Fuel (MOX):Open technical and security issues

Once disposition campaign completed: still 15 to 25 a remaining lifetime of facility left: MOX as the precursor for a

Pu fuel cycle? Use of military Pu in commercial reactors:

undermining nonproliferation interests?

Use of MOX facility for fuel production of military reactors?

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Mixed Oxide Fuel (MOX):Open technical and security issues

Utilities expect higher operating costs: Higher in-core n production rates* Higher heat output* Difficulties of using and storing MOX

What incentives fees to be paid to utilities?

* Compared to ordinary reactor fuel

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4. SECURITY ASPECTS

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Diversion due to measurement uncertainties?

MUF at nuclear material processing site:

Plant holdup (tanks, pipes, drains, etc.) Wide variations of material matrix Statistical variations Accidental spills Recording, reporting, rounding errors Honey pot syndrome

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Uncertainties/Fraud

Nuclear material storage site: Statistical uncertainty of measurement

during non-destructive testing of container content

Covert faking of “intact”container seals Checking of container presence only

(without verifying content)

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US Cumulative Pu Inventory Difference (1944-1994) in kg

Hanford: + 1 266 Argonne West: -3.4 Lawrence L.: +5.5 Idaho NE: -5.6+ = decrease from book

inventory

Rocky Fl.: + 1 192 Los Alamos: +48 Savannah R.: + 232 Other sites: + 17- = increase from book

inventory

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Security Risks during Transport

Transport = moving target is generally at higher security risk than stationary target

Rail/road transport: 4 highly damaging attack modes possible*

Sea transport: continuous navy escort required

* NATO Expert Group “Terrorist attacks on nuclear power plants and nuclear material transports”, Rep. SST.CLG.978964(July 2004)

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Countering Transport Security Risks

Specially designed Super-containers necessary for transport of nuclear warheads

Kevlar-based blankets needed to protect containers with dismantled nuclear weapon components

Heavy-duty manipulators required for remote handling of nuclear warheads

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Spent Fuel Standard (SFS): adequate security?

Radiation barrier decays with t½ ~ 30 a: minimal deterrent after 300 a (Pu mining)

Cans embedded in radioactive glass or ceramic: technically feasible to remove cans from external radiation barrier (re-start of reprocessing)

Suicide terrorist not incapacitated (max. -radiation dose rate 6 Sv/20 min)

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5. CONCLUSIONS & RECOMMENDATIONS

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Comparative assessment of Pu elimination methods (1)

MOX fuel, vitrification and geologic depository can only delay reprocessing

MOX will require about 250 a of reactor operation/100 t Pu

MOX require the operation of many installations (= extensive transport of Pu-fuel and radwaste)

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Comparative assessment of Pu elimination methods (2)

Pu storage in deep boreholes requires minimum operations, easy to supervise (e.g., CCTV + satellite)

Vitrification: simultaneous elimination of high level radwaste and Pu

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Comparative assessment of Pu elimination methods (3)

Irreversible Pu destruction only by transmutation

Supervision of spallation units depends on design (e.g., operation as dual use facility feasible)

Transmutation requires assurance of proliferation resistance

Transmutation requires the operation of many installations (= extensive transport)

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Comparative assessment of Pu elimination methods (4)

R&D requirements: minimum – Pu storage in deep boreholesmaximum – transmutation

Cost estimates (for elimination of 400 t Pu):*vitrification/borehole – EURO 2-7 billiontransmutation – EURO 70 billion

* for comparison: total cost US nuclear weapon development programme: EURO 3 000 billion

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Comparative assessment of Pu elimination methods (5)

Can-in-canister: shortest start-up and completion time of all Pu disposition methods*: 7a, resp. 18 a**

MOX implementation: 25 – 30 a ***

*except deep borehole storage**assumption: 5 t Pu/a*** assuming European MOX facilities as interim solution

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Comparative assessment of Pu elimination methods (6)

SYNROC is superior to glass vitrification:

chemical stability n stability resistance to Pu recovery

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Recommendations1. There is no single, perfect method of

eliminating nuclear material stockpiles: each method has its pros and cons

2. Overall immobilization is superior to reactor/accelerator approach:

Nonproliferation Timing Cost Security

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Recommendations

3. Establish an international register of inventories and production capabilities for all relevant nuclear materials

4. Demand detailed material balances5. End discrimination between

military and civilian Pu stockpiles

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Recommendations

6. Strengthen the existing international monitoring system:

Kr 85 monitoring Tagging techniques Tamper-proof seals

Excess weapon grade Pu poses a clear and present danger to

national and international security

US National Academy of Sciences,Management and Disposition of Excess

Plutonium,Vol. 1+2, National Academy Press, Washington,

D.C., 1994 and 1995

The fate of the Russian 130 to 160 t of Pu is not only of interest with regard to disarmament, but

represents a global interest in survival, which requires from us

solutions, or at least a minimization of risks.

Joschka FISCHER,Minister of Foreign Affairs,

Germany,Sept. 1, 2000

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Benefits of Pu disposition programmes should not be exaggerated:

US and Russia can reconstitute Cold War sized arsenals with remaining, non-surplus Pu stocks

Disposition is only an important first step toward a more comprehensive campaign

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Governmental leadership is needed in bringing together the non-

proliferation community, industrial participants and the public on a

common agenda to rid the world of surplus weapons material

as soon as possible.

Nuclear Energy Institute, March 11, 1998