analysis on the potential implications of a terrorist attack at u.s. spent nuclear fuel storage...

ANALYSIS ON THE POTENTIAL ANALYSIS ON THE POTENTIAL IMPLICATIONS OF A TERRORIST IMPLICATIONS OF A TERRORIST

ATTACK AT U.S. SPENT NUCLEAR ATTACK AT U.S. SPENT NUCLEAR FUEL STORAGE FACILITIESFUEL STORAGE FACILITIES

Derek Favret, Michael Stabin, Frank Parker, Jim Clarke and David Kosson

IntroductionIntroduction

September 11, 2001September 11, 2001

Nuclear Industry Nuclear Industry targetedtargeted

Successful attack Successful attack would potentially would potentially cause devastating cause devastating release of radioactive release of radioactive materialmaterial

(Source: http://en.wikipedia.org/wiki/Image:WTC_attack_9-11.jpg)

HeadlinesHeadlines

“…“…could cause contamination problems could cause contamination problems significantly worse than those from significantly worse than those from Chernobyl”Chernobyl”

“…“…could release up to 20 times the could release up to 20 times the 137137Cs Cs released from Chernobyl”released from Chernobyl”

“…“…disaster of catastrophic proportions”disaster of catastrophic proportions”

BackgroundBackground

Circles represent sites with one reactor, squares represent plants with two, and stars represent three. Open symbols represent sites with at least one shutdown reactor (Source: Alvarez, et al., Reducing the Hazards from Stored Spent Power-Reactor Fuel in the United States, 2003).

Light Water ReactorsLight Water Reactors

(Source: National Academies, “Safety and Security of Commercial Spent Nuclear Fuel Storage, 2006)

Spent Fuel Pool (SFP)Spent Fuel Pool (SFP)

““Pool within Pool” Pool within Pool”

Building: Industrial-type Building: Industrial-type designdesign

Steel superstructure Steel superstructure above poolabove pool

Pool depth: 12-15mPool depth: 12-15m

Pool volume: ~4000mPool volume: ~4000m33

No drains or low-level No drains or low-level pathwayspathways

(Source: NRC, Spent Fuel Pool, 2003)

REALISTIC THREATREALISTIC THREAT

““Severe consequences Severe consequences and unpredictability of and unpredictability of terrorists”terrorists”

National Academies:National Academies: ““difficult but possible”difficult but possible” ““additional analysis additional analysis

needed” needed”

UNREALISTIC THREATUNREALISTIC THREAT

““Robust construction Robust construction and stringent security and stringent security requirements”requirements”

““Critics overestimate Critics overestimate consequences and consequences and underestimate ability underestimate ability to cool fuel in to cool fuel in damaged pool”damaged pool”

Probability of Successful AttackProbability of Successful Attack

ScenarioScenario

Loss of Coolant Event – “Zirconium Fire”Loss of Coolant Event – “Zirconium Fire”

““Realistic” worst-case analysisRealistic” worst-case analysis

SFP located in rural and urban areasSFP located in rural and urban areas

Dispersion ModelingDispersion Modeling

Defense Threat Defense Threat Reduction AgencyReduction Agency

CBRNE modeling toolCBRNE modeling tool

Gaussian Puff model Gaussian Puff model “SCIPUFF”“SCIPUFF”

Joined with RASCAL and Joined with RASCAL and climatology database for climatology database for Nuclear Reactor Nuclear Reactor modelingmodeling

HPAC Incident ModelsHPAC Incident Models

Chemical/Biological Chemical/Biological Facility Damage Facility Damage

Chemical/Biological Chemical/Biological WeaponWeapon

Industrial FacilityIndustrial Facility

Industrial Industrial TransportationTransportation

Nuclear WeaponNuclear Weapon

Nuclear Weapon Nuclear Weapon Accident/IncidentAccident/Incident

Radiological Weapon Radiological Weapon IncidentIncident

Missile InterceptMissile Intercept

HPACHPAC

High-resolution High-resolution weather, terrain, and weather, terrain, and land cover dataland cover data

Surface and Upper air Surface and Upper air climatologyclimatology

Historical, real-time or Historical, real-time or forecast weather forecast weather optionsoptions

HPAC ParametersHPAC Parameters

Spent Fuel ReleaseSpent Fuel Release Zirconium FireZirconium Fire Fuel Cladding FailureFuel Cladding Failure

Worst-case settingsWorst-case settings

Historical WeatherHistorical Weather

Parameters Parameters (cont.)(cont.)

Release Height – effective release height Release Height – effective release height

BuoyancyBuoyancy Vertical Exhaust Velocity Vertical Exhaust Velocity Temperature above Ambient (20Temperature above Ambient (20ooC)C) Exhaust AreaExhaust Area

RESRADRESRAD

Argonne National LabArgonne National Lab

Calculates site-specific Calculates site-specific residual radiation levels, residual radiation levels, lifetime dose and excess lifetime dose and excess lifetime cancer risks to lifetime cancer risks to chronically exposed on-chronically exposed on-site residentssite residents

Pathway AnalysisPathway Analysis

RESRAD: Pathway AnalysisRESRAD: Pathway Analysis

RESRAD ScenariosRESRAD Scenarios

Pathway Resident Farmer

Suburban Resident

Industrial Worker

Recreationist

External gamma exposure

Yes Yes Yes Yes

Inhalation of dust Yes Yes Yes Yes

Radon inhalation Yes Yes Yes Yes

Ingestion of plant foods Yes Yes No No

Ingestion of meat Yes No No Yes

Ingestion of milk Yes No No No

Ingestion of fish Yes No No Yes

Ingestion of soil Yes Yes Yes Yes

Ingestion of water Yes No No No

RESRAD ParametersRESRAD Parameters

Default parametersDefault parameters

Radionuclides Radionuclides determined by HPACdetermined by HPAC

Soil density =1.5 g cmSoil density =1.5 g cm-3-3

Contamination depth = Contamination depth = 0.1 m0.1 m

RESULTSRESULTS

HPACHPACRURAL SCENARIORURAL SCENARIO

April, May & December April, May & December yielded areas of yielded areas of contamination ~ 560 kmcontamination ~ 560 km2 2

(0.037 GBq m(0.037 GBq m-2-2 contour) contour)

April yielded area of April yielded area of contamination ~ 55 kmcontamination ~ 55 km2 2

(0.37 GBq m(0.37 GBq m-2-2 contour) contour)

Majority of plumes released Majority of plumes released in generally Northern in generally Northern directiondirection

April represents worst-case April represents worst-case dispersiondispersion

URBAN SCENARIOURBAN SCENARIO

January yielded area of January yielded area of contamination ~ 202 kmcontamination ~ 202 km2 2

(0.037 GBq m(0.037 GBq m-2-2 contour) contour)

January yielded area of January yielded area of contamination ~ 14 kmcontamination ~ 14 km22 (0.37 GBq m(0.37 GBq m-2-2 contour) contour)

Majority of plumes released Majority of plumes released in generally Northern-in generally Northern-Eastern directionEastern direction

January represents worst-January represents worst-case dispersioncase dispersion

N

N

Rural Scenario

Annual Dose Rate:

70 Sv y-1

7 Sv y-1

700 mSv y-1

70 mSv y-1

Urban Scenario

Ground Deposition

37 GBq m-2

3.7 GBq m-2

0.37 GBq m-2

0.037 GBq m-2

HPAC HPAC

Total Activity Released = Total Activity Released = 4.8E+08 GBq (13 MCi)4.8E+08 GBq (13 MCi)

Radionuclides Radionuclides contributing to ground contributing to ground deposition: deposition:

137137Cs = 33.08%Cs = 33.08% 134134Cs = 17.69%Cs = 17.69% 9090Sr = 1.54%Sr = 1.54% 106106Ru = 0.26%Ru = 0.26% 125125Sb = 0.22%Sb = 0.22% 144144Ce = 0.08%Ce = 0.08% 147147Pm = 0.02%Pm = 0.02%

NOTE: (Noble Gases = 12.31%, external dose contribution only)(Noble Gases = 12.31%, external dose contribution only)

Activity Release (GBq):Activity Release (GBq): HPAC vs. Chernobyl HPAC vs. Chernobyl

HPAC Scenarios HPAC Scenarios (Mean)(Mean)

137137Cs = 1.48E+08Cs = 1.48E+08

134134Cs = 7.96E+07Cs = 7.96E+07

9090Sr = 7.03E+06Sr = 7.03E+06

ChernobylChernobyl

137137Cs = 8.50E+07Cs = 8.50E+07

134134Cs = 5.40E+07Cs = 5.40E+07

9090Sr = 1.00E+07Sr = 1.00E+07

RESRAD: DoseRESRAD: Dose

Rural Scenario: 0.37 GBq m-2 (10 mCi m-2) contour

RESRAD: DoseRESRAD: Dose

Urban Scenario: 0.37 GBq m-2 (10 mCi m-2) contour

Protective Action Guidelines (PAG)Protective Action Guidelines (PAG)

Phase Protective Action PAG

Early- Limit Emergency

Worker Exposure 0.05 Sv (5 rem)

  - Sheltering of Public0.01-0.05 Sv (1-5 rem)

projected dose

  - Evacuation of Public0.01-0.05 Sv (1-5 rem)

projected dose

Intermediate - Limit Worker Exposure 0.05 Sv (5 rem) y-1

 - Relocation of General

Public0.02 Sv (2 rem) projected dose

first year

Late - Final Cleanup Actions based on “Optimization”

Source: Federal Registrar, Vol 71, No. 1, 3 Jan 06

RESRAD: DoseRESRAD: Dose

Rural Scenario: 0.037 GBq m-2 (1 mCi m-2) contour

RESRAD: DoseRESRAD: Dose

Urban Scenario: 0.037 GBq m-2 (1 mCi m-2) contour

RESRAD: RESRAD: 137137Cs contributions to DoseCs contributions to Dose

Rural Scenario: 0.037 GBq m-2 (1 mCi m-2) contour

RESRAD: RESRAD: 9090Sr contributions to DoseSr contributions to Dose

Rural Scenario: 0.037 GBq m-2 (1 mCi m-2) contour

Headlines in ReviewHeadlines in Review

“…“…could cause contamination problems could cause contamination problems significantly worse than those from significantly worse than those from Chernobyl”Chernobyl”

“…“…could release up to 20 times the could release up to 20 times the 137137Cs Cs released from Chernobyl”released from Chernobyl”

“…“…disaster of catastrophic proportions”disaster of catastrophic proportions”

ConclusionsConclusionsHPAC analysis of worst-case incident results in HPAC analysis of worst-case incident results in contamination levels in general agreement with contamination levels in general agreement with Chernobyl.Chernobyl.

RESRAD analysis shows potential for acute effects RESRAD analysis shows potential for acute effects are unlikely.are unlikely.

Dose levels in the worst case analysis are high in Dose levels in the worst case analysis are high in some zones, showing that restrictions on worker some zones, showing that restrictions on worker access and temporary relocation of some populations access and temporary relocation of some populations will be necessary.will be necessary.

Although significant, an incident that results in a zirconium fire at a SFP may not be as catastrophic as

suggested.

For More Information:For More Information:

HPACHPAC

http://www.dtra.mil/toolbox/directorates/td/programs/ http://www.dtra.mil/toolbox/directorates/td/programs/ acec/hpac.cfmacec/hpac.cfm

RESRADRESRAD

http://web.ead.anl.gov/resrad/home2http://web.ead.anl.gov/resrad/home2