Radiological Dispersal Devices (RDDs)
Radiological Dispersal Devices (RDDs):
Dirty Bomb, Other Dispersal Methods
- Radiological Dispersal Device (RDD) is any device that causes the purposeful dissemination of radioactive material without a nuclear detonation.
- Dispersion methods can be
- "Dirty Bomb" = Explosive method of dispersion (See Figure 1)
- Explosion produces radioactive and nonradioactive shrapnel and radioactive dust
- Explosion causes
- Radiation contamination, commonly (Animations)
- Radiation exposure only in certain circumstances (Animations)
- Physical injury
- Burns
- Panic, fear
Figure 1. Dirty Bomb: Radiological Dispersal Device Using Explosive
- Other Dispersal Methods
- Passive or active dispersion of unsealed radioactive sources, e.g., deposit in soil or water, drop from airborne device (See Figure 2)
- Radioactive sources can be solid, aerosol, gas, or liquid
- Contamination of people may occur via air, water, soil, or food
Figure 2. Dispersal of Radioactive Material by Aircraft
- Explosive RDDs cannot cause mass casualties on the scale of a nuclear explosion. All or most fatalities or injuries will probably due to explosion itself.
- While large numbers of people in a densely populated area around the detonation of a RDD might become contaminated and require decontamination, few if any will be contaminated to a level that requires medical treatment.
- Local health authorities will have to assess the persons who were very close to the point of release for the need for medical intervention.
- The health and environmental consequences from RDDs, will depend on
- The design of the device
- Type and quantity of radioactive material
- The pattern of dispersion following the release
- RDDs may affect
- Small, localized areas (e.g., a street, single building, or city block)
- Large areas, up to several square miles, depending on the nature of the dispersion and the amount and type of radioactive material
- Other hazards may also be present
- Fire, smoke, shock, shrapnel (from an explosion)
- Industrial chemicals
- Secondary device
- Radioactive decontamination of persons and areas affected may be required.
References:
- Harper FT, Musolino SV, Wente WB. Realistic radiological dispersal device hazard boundaries and ramifications for early consequence management decisions. Health Phys. 2007 Jul;93(1):1-16. [PubMed Citation]
- Smith JM, Ansari A, Harper FT. Hospital management of mass radiological casualties: reassessing exposures from contaminated victims of an exploded radiological dispersal device. Health Phys. 2005 Nov;89(5):513-20. [PubMed Citation]
- Musolino SV, Harper FT. Emergency Response Guidance for the First 48 Hours after the Outdoor Detonation of an Explosive Radiological Device. Health Physics 2006 Apr;90(4):377-85. [PubMed Citation]
- Management of Terrorist Events Involving Radioactive Material, National Council on Radiation Protection and Measurements, NCRP Report No. 138, Bethesda, MD, 2001.
- Management of Persons Accidentally Contaminated with Radionuclides, National Council on Radiation Protection and Measurements, NCRP Report No. 65, Bethesda, MD, 1980.
- Handbook for responding to a radiological dispersal device first responders's guide — the first 12 hours (PDF - 4.26 MB). (Conference of Radiation Control Program Directors, Inc., September 2006)
- Department of Homeland Security Working Group on Radiological Dispersal Device (RDD) Preparedness, Medical Preparedness and Response Sub-Group, 12/09/03 Version (PDF - 335 KB).
- Radiological Dispersal Device (PDF - 380 KB) (Human Health Fact Sheet, Argonne National Laboratory, August 2005)
- FAQs About Dirty Bombs (HHS/CDC, 05/10/2006)
- Backgrounder on Dirty Bombs (NRC)
- Tochner ZA,Lehavi O,Glatstein E, Radiation Bioterrorism, in Harrison's Principles of Internal Medicine, 16th Edition, Kasper DL, et al. (Eds.), New York, McGraw-Hill, 2004, pp. 1294-1300.
- Patient Decontamination: Recommendations for Hospitals (PDF - 124 K) (The Hospital and Healthcare System Disaster Interest Group and the California Emergency Medical Services Authority, July 2005, EMSA #233, Radiological Contamination, pages 11-16)
- Marcus CS, Siegel JA, Sparks RB. Medical Management of Radiocontaminated Patients (PDF - 1.36 MB) (Los Angeles County Department of Health Services, Emergency Medical Services Agency, June 2006)
- Marcus, CS. Administration of decorporation drugs to treat internal radionuclide contamination: medical emergency response to radiologic incidents. RSO Magazine, 2004;9(5):9-15. (PDF - 34 KB)
- Radiological Attack — Radiological Dispersal Devices (PDF - 127 KB) (The California Emergency Medical Services Authority)
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Potential Isotopes Used in RDDs
Basic Radiological Properties of RDD Isotopes
Basic Radiological Properties of Nine Key Radionuclides for RDDs |
|---|
Isotope |
Half-Life
(years) |
Specific Activity
(Ci/g) |
Decay Mode |
Radiation Energy (MeV) |
Alpha
(α) |
Beta
(β) |
Gamma
(γ) |
Americium-241 |
430 |
3.5 |
α |
5.5 |
0.052 |
0.033 |
Californium-252 |
2.6 |
540 |
α (SF, EC) |
5.9 |
0.0056 |
0.0012 |
Cesium-137 |
30 |
88 |
β, IT |
- |
0.19, 0.065 |
0.60 |
Cobalt-60 |
5.3 |
1,100 |
β |
- |
0.097 |
2.5 |
Iridium-192 |
0.2 (74 d) |
9,200 |
β, EC |
- |
0.22 |
0.82 |
Plutonium-238 |
88 |
17 |
α |
5.5 |
0.011 |
0.0018 |
Polonium-210 |
0.4 (140 d) |
4,500 |
α |
5.3 |
- |
- |
Radium-226 |
1,600 |
1.0 |
α |
4.8 |
0.0036 |
0.0067 |
Strontium-90 |
29 |
140 |
β |
- |
0.20, 0.94 |
- |
SF = spontaneous fission;
IT = isomeric transition;
EC = electron capture.
A hyphen means not applicable.
The radiation energies for cesium-137 include the
contributions of barium-137 metastable (Ba-137m),
and those for strontium-90 include the contributions
of yttrium-90.
|
Adapted from Radiological Dispersal Device (PDF - 380 KB) Human Health Fact Sheet, Argonne National Laboratory, August 2005
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Potential RDD Effects
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Radiation Response Worker Exposure Guides (PAGs) in the Early Phase
Explaining protective actions and guides (PAGs) | Phases of response: early, intermediate, late
Total Effective Dose Equivalent (TEDE)
Guideline |
Worker Activity |
Condition |
5 rem (0.05 Sv) |
All occupational exposures |
- All reasonably achievable actions have been taken to minimize dose.
|
10 rem (0.1 Sv) |
Protecting valuable property necessary for public welfare (e.g., a power plant) |
- All appropriate actions and controls have been implemented; however exceeding 5 rem is unavoidable.
- Responders have been fully informed of the risks of exposures they may experience.
- Dose > 5 rem is on a voluntary basis.
- Appropriate respiratory protection and other PPE is provided and used.
- Monitoring is available to project or measure dose
|
25 rem (0.25 Sv) |
Lifesaving or protection of large populations
RDD incident: this dose level unlikely to be reached for response workers
IND incident: this dose level is conceivable for response workers
|
- All appropriate actions and controls have been implemented; however exceeding 5 rem is unavoidable.
- Responders have been fully informed of the risks of exposures they may experience.
- Dose > 5 rem is on a voluntary basis.
- Appropriate respiratory protection and other PPE is provided and used.
- Monitoring is available to project or measure dose.
|
1 Adapted from Planning Guidance for Protection and Recovery Following Radiological Dispersal Device (RDD) and Improvised Nuclear Device (IND) Incidents (PDF - 394 KB) (DHS/FEMA, published in Federal Register, August 1, 2008, Z-RIN 1660-ZA02)
2 In the intermediate and late phases, standard worker protections, including the 5 rem occupational dose limit, would normally apply.
3 Other decision points for restricting response workers' activities have been recommended by various other agencies, as noted in table below.
Agency |
Summary Information |
Original Document |
|---|
National Council on Radiation Protection and Measurement (NCRP) |
NCRP Radiation Protection Guidelines: Control of Radiation Dose in the Control Zones |
Key Elements of Preparing Emergency Responders for Nuclear and Radiological Terrorism (NCRP Commentary No. 19, December 2005, page 19, purchase required; see Free Overview (PDF - 219 KB)) |
International Atomic Energy Agency (IAEA) |
IAEA Emergency Worker Turn-back Dose Guidance |
Manual for First Responders to a Radiological Emergency (PDF - 2.2 MB) (CTIF, IAEA, PAHO, WHO, October 2006, page 41) |
Conference of Radiation Control Program Directors, Inc. (CRCPD) |
CRCPD Turn-back Exposure Rates and Dose Guidelines |
Handbook for Responding to a Radiological Dispersal Device (Dirty Bomb): First Responder's Guide: The First 12 Hours (CRCPD Publication 06-6) (PDF - 4.26 MB), page 28. Conference of Radiation Control Program Directors, Inc. Frankfort, Kentucky, 2006. |
International Commission on Radiological Protection (ICRP) |
ICRP Guidance for Occupational Exposure |
Protecting People Against Radiation Exposure in the Event of a Radiological Attack (International Commission on Radiological Protection, ICRP Publication 96, 2005, page 51) |
4 Because each incident is unique, it is impossible to develop a single turn-back dose level for all responders in all events. Therefore, the 5, 10, and 25 rem guidelines this table should not be viewed as absolute standards applicable to the full range of incidents covered in this guidance, but rather serve as decision points for making worker protection decisions during emergencies. Incident Commanders should use the "as low as reasonably achievable (ALARA)" principle. During planning and training, managers and responders should acquire the knowledge necessary to understand the acute and chronic risks of exposure, especially at higher radiation levels.
5 By agreement with the Environmental Protection Agency (EPA), guidance in this August 1, 2008 Federal Register document will be incorporated without change into the currently ongoing revision of the 1992 EPA Manual of Protective Actions for Nuclear Incidents (the PAG Manual). This Federal Register notice of final guidance will therefore, sunset upon publication of the new EPA PAG Manual.
6 For potential doses >10 rem, special medical monitoring programs should be employed, and exposure should be tracked in terms of the unit of absorbed dose (rad) rather than TEDE (rem).
See also:
Personal Protective Equipment (PPE)
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