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