ANALYSIS ON THE POTENTIAL IMPLICATIONS OF A TERRORIST ATTACK AT

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					  ANALYSIS ON THE POTENTIAL
 IMPLICATIONS OF A TERRORIST
ATTACK AT U.S. SPENT NUCLEAR
   FUEL STORAGE FACILITIES




    Derek Favret, Michael Stabin, Frank Parker,
           Jim Clarke and David Kosson
              Introduction
September 11, 2001

Nuclear Industry
targeted

Successful attack
would potentially
cause devastating
release of radioactive
material
                   (Source: http://en.wikipedia.org/wiki/Image:WTC_attack_9-11.jpg)
             Headlines
“…could cause contamination problems
significantly worse than those from
Chernobyl”

“…could release up to 20 times the 137Cs
released from Chernobyl”

“…disaster of catastrophic proportions”
                           Background




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 Reactors




(Source: National Academies, “Safety and Security of Commercial Spent Nuclear
Fuel Storage, 2006)
             Spent Fuel Pool (SFP)
                                       “Pool within Pool”
                                       Building: Industrial-type
                                       design
                                       Steel superstructure
                                       above pool
                                       Pool depth: 12-15m
                                       Pool volume: ~4000m3
(Source: NRC, Spent Fuel Pool, 2003)   No drains or low-level
                                       pathways
Probability of Successful Attack
UNREALISTIC THREAT       REALISTIC THREAT


“Robust construction     “Severe consequences
and stringent security   and unpredictability of
requirements”            terrorists”

“Critics overestimate
                         National Academies:
consequences and
                          “difficult but possible”
underestimate ability
to cool fuel in           “additional analysis

damaged pool”              needed”
              Scenario

Loss of Coolant Event – “Zirconium Fire”

“Realistic” worst-case analysis

SFP located in rural and urban areas
        Dispersion Modeling
Defense Threat
Reduction Agency

CBRNE modeling tool

Gaussian Puff model
“SCIPUFF”

Joined with RASCAL and
climatology database for
Nuclear Reactor
modeling
      HPAC Incident Models
Chemical/Biological   Nuclear Weapon
Facility Damage
                      Nuclear Weapon
Chemical/Biological   Accident/Incident
Weapon
                      Radiological Weapon
Industrial Facility   Incident

Industrial            Missile Intercept
Transportation
HPAC
   High-resolution
   weather, terrain, and
   land cover data

   Surface and Upper air
   climatology

   Historical, real-time or
   forecast weather
   options
             HPAC Parameters

Spent Fuel Release
   Zirconium Fire
   Fuel Cladding Failure


Worst-case settings

Historical Weather
           Parameters (cont.)

Release Height – effective release height

Buoyancy
   Vertical Exhaust Velocity
   Temperature above Ambient (20oC)
   Exhaust Area
RESRAD
    Argonne National Lab

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

    Pathway Analysis
RESRAD: Pathway Analysis
                RESRAD Scenarios
Pathway                    Resident   Suburban   Industrial   Recreationist
                            Farmer    Resident    Worker

External gamma               Yes        Yes         Yes           Yes
exposure
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 Parameters
Default parameters

Radionuclides
determined by HPAC

Soil density =1.5 g cm-3

Contamination depth =
0.1 m
RESULTS
                      HPAC
RURAL SCENARIO                URBAN SCENARIO
April, May & December         January yielded area of
yielded areas of              contamination ~ 202 km2
contamination ~ 560 km2       (0.037 GBq m-2 contour)
(0.037 GBq m-2 contour)
                              January yielded area of
April yielded area of         contamination ~ 14 km2
contamination ~ 55 km2        (0.37 GBq m-2 contour)
(0.37 GBq m-2 contour)
Majority of plumes released   Majority of plumes released
in generally Northern         in generally Northern-
direction                     Eastern direction

April represents worst-case   January represents worst-
dispersion                    case dispersion
                  Rural Scenario       Ground Deposition
N
                                       37 GBq m-2
                                       3.7 GBq m-2
                                       0.37 GBq m-2
                                       0.037 GBq m-2


                                         Urban Scenario
                                   N
    Annual Dose Rate:
    70 Sv y-1
    7 Sv y-1
    700 mSv y-1
    70 mSv y-1
                        HPAC
Total Activity Released =
4.8E+08 GBq (13 MCi)

Radionuclides
contributing to ground
deposition:
 
     137Cs = 33.08%
 
     134Cs = 17.69%

 
     90Sr = 1.54%

 
     106Ru = 0.26%

 
     125Sb = 0.22%

 
     144Ce = 0.08%

 
     147Pm = 0.02%




NOTE: (Noble Gases = 12.31%, external dose contribution only)
        Activity Release (GBq):
                HPAC vs. Chernobyl


HPAC Scenarios (Mean)         Chernobyl

 137Cs   = 1.48E+08         137Cs    = 8.50E+07

 134Cs   = 7.96E+07         134Cs    = 5.40E+07

 90Sr   = 7.03E+06          90Sr   = 1.00E+07
       RESRAD: Dose




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




Urban Scenario: 0.37 GBq m-2 (10 mCi m-2) contour
 Protective Action Guidelines (PAG)
  Phase          Protective Action                        PAG
             - Limit Emergency Worker
   Early         Exposure                           0.05 Sv (5 rem)
                                                0.01-0.05 Sv (1-5 rem)
             - Sheltering of Public                  projected dose
                                                0.01-0.05 Sv (1-5 rem)
             - Evacuation of Public                  projected dose

Intermediate - Limit Worker Exposure               0.05 Sv (5 rem) y-1
             - Relocation of General        0.02 Sv (2 rem) projected dose
                Public                                   first year

   Late      - Final Cleanup Actions            based on “Optimization”
           Source: Federal Registrar, Vol 71, No. 1, 3 Jan 06
       RESRAD: Dose




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




Urban Scenario: 0.037 GBq m-2 (1 mCi m-2) contour
RESRAD: 137Cs contributions to Dose




      Rural Scenario: 0.037 GBq m-2 (1 mCi m-2) contour
RESRAD: 90Sr contributions to Dose




       Rural Scenario: 0.037 GBq m-2 (1 mCi m-2)
       contour
      Headlines in Review
“…could cause contamination problems
significantly worse than those from
Chernobyl”

“…could release up to 20 times the 137Cs
released from Chernobyl”

“…disaster of catastrophic proportions”
                Conclusions
HPAC analysis of worst-case incident results in
contamination levels in general agreement with
Chernobyl.
RESRAD analysis shows potential for acute effects
are unlikely.
Dose levels in the worst case analysis are high in
some zones, showing that restrictions on worker
access and temporary relocation of some populations
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:

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


RESRAD

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

				
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posted:11/29/2011
language:English
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