Intervention for Chronic and Emergency Exposure SituationsIntervention for Chronic and Emergency Exposure Situations

Module IX Module IX Basic Concepts for Emergency Basic Concepts for Emergency preparedness and Response for a nuclear preparedness and Response for a nuclear

accident or radiological emergencyaccident or radiological emergency

Emergency Threat CategoriesEmergency Threat Categories LectureLecture

IAEA Post Graduate Educational Course in Radiation Protection and Safety of Radiation Sources

Module IX.3 - Basic Concepts 2

Assessment of ThreatsAssessment of Threats

The nature and extent of emergency The nature and extent of emergency arrangements arrangements have tohave to be commensurate be commensurate with the potential magnitude and nature of with the potential magnitude and nature of the hazard associated with the facility or the hazard associated with the facility or activityactivity

The threat assessment The threat assessment mustmust be be periodically reviewed to take into account periodically reviewed to take into account changes in to the threats within and changes in to the threats within and outside the outside the countrycountry and the experience and the experience and lessons from previous events and lessons from previous events involving relevant practices and sourcesinvolving relevant practices and sources

Module IX.3 - Basic Concepts 3

Assessment of Threats (cont’d)Assessment of Threats (cont’d)

The threat assessment The threat assessment has tohas to identify identify installations, sources, practices, on-site areas, installations, sources, practices, on-site areas, off-site areas or locations for which nuclear or off-site areas or locations for which nuclear or radiological emergencies could warrant:radiological emergencies could warrant: precautionaryprecautionary urgent protective actions to urgent protective actions to

prevent severe deterministic health effectsprevent severe deterministic health effects urgent protective actions to reduce stochastic urgent protective actions to reduce stochastic

effectseffects agricultural and ingestion countermeasures agricultural and ingestion countermeasures

and long term protective measures and long term protective measures protection for the workers undertaking an protection for the workers undertaking an

interventionintervention

Module IX.3 - Basic Concepts 4

Threat CategoriesThreat Categories

Nuclear and radiation threats are grouped Nuclear and radiation threats are grouped according to the five threat categoriesaccording to the five threat categories Categories I through IV represent decreasing Categories I through IV represent decreasing

levels of threat and therefore decreasing levels of threat and therefore decreasing emergency preparedness and response emergency preparedness and response requirementsrequirements

Category IV is the minimum level of threat Category IV is the minimum level of threat assumed to exist everywhere and thusassumed to exist everywhere and thus always always appliesapplies possibly along with other categories possibly along with other categories

Category V is a special category and Category V is a special category and may may applyapply along with other categories along with other categories

Module IX.3 - Basic Concepts 5

Threat Category IThreat Category I

Nuclear installations for which events that Nuclear installations for which events that could give rise to severe deterministic could give rise to severe deterministic health effects off-site are postulated or health effects off-site are postulated or have occurred in similar installations, have occurred in similar installations, including very low probability eventsincluding very low probability events

Module IX.3 - Basic Concepts 6

Threat Category IIThreat Category II

Installations for which events that can Installations for which events that can give rise to off-site doses warranting give rise to off-site doses warranting urgent protective actions consistent with urgent protective actions consistent with international standards are postulated or international standards are postulated or have occurred in similar installationshave occurred in similar installations This category (as opposed to category I This category (as opposed to category I

threats) has no credible events threats) has no credible events postulated that could give rise to off-postulated that could give rise to off-site doses resulting in severe site doses resulting in severe deterministic health effectsdeterministic health effects

Module IX.3 - Basic Concepts 7

Threat Category IIIThreat Category III

Installations for which events that could Installations for which events that could give rise to doses on-site resulting in give rise to doses on-site resulting in severe deterministic health effects are severe deterministic health effects are postulated or have occurred within similar postulated or have occurred within similar installationsinstallations This category (as opposed to category II This category (as opposed to category II

threats) has no credible events threats) has no credible events postulated for which urgent off-site postulated for which urgent off-site protective actions are warrantedprotective actions are warranted

Module IX.3 - Basic Concepts 8

Threat Category IVThreat Category IV

Minimum level of threat assumed for all Minimum level of threat assumed for all countriescountries and jurisdictions and jurisdictions

Module IX.3 - Basic Concepts 9

Threat Category VThreat Category V

Areas that have a significant probabilityAreas that have a significant probability of of being contaminated to levels being contaminated to levels necessitating food restrictions consistent necessitating food restrictions consistent with international standards as a result of with international standards as a result of events at installations in threat categories events at installations in threat categories I or II, including installations in other I or II, including installations in other countriescountries

Module IX.3 - Basic Concepts 10

Introduction - Requirements (GS-R-2) Are Established Introduction - Requirements (GS-R-2) Are Established for Threat Categoriesfor Threat Categories

Threat Threat CategoryCategory Radiological ThreatRadiological Threat

II Severe deterministic health effects off-siteSevere deterministic health effects off-site

IIIIWarranting urgent protective actions off-site, Warranting urgent protective actions off-site, deterministic health effects on-sitedeterministic health effects on-site

IIIIIINo urgent protective actions off-site are warranted, No urgent protective actions off-site are warranted, severe deterministic health effects on-sitesevere deterministic health effects on-site

IVIV Minimum level of threat – all countriesMinimum level of threat – all countries

VVFood contamination due to transboundary Food contamination due to transboundary contamination necessitating food restrictionscontamination necessitating food restrictions

Module IX.3 - Basic Concepts 11

The Safety Requirements (GS-R-2) The Safety Requirements (GS-R-2)

Sets requirements for dangerous sources and Sets requirements for dangerous sources and defines: defines:

““Dangerous source” “could, if not under Dangerous source” “could, if not under control, give rise to exposure sufficient to cause control, give rise to exposure sufficient to cause severe deterministic effects”severe deterministic effects”

“ “Severe deterministic effect” that “is fatal or Severe deterministic effect” that “is fatal or life threatening or results in a permanent injury life threatening or results in a permanent injury that decreases the quality of life” that decreases the quality of life”

Module IX.3 - Basic Concepts 12

Severe Deterministic EffectSevere Deterministic Effect

Reduces the quality of life Reduces the quality of life

Module IX.3 - Basic Concepts 13

Threat AssessmentThreat Assessment

Threat categories of facilities and practices based on:Threat categories of facilities and practices based on:- Reactor power levelsReactor power levels- Spent fuel inventoriesSpent fuel inventories- Activity/D value ratiosActivity/D value ratios- Dose rates at 1 meterDose rates at 1 meter- Potential for criticalityPotential for criticality- Probability of encounteringProbability of encountering

an uncontrolled sourcean uncontrolled source- Scrap metal dealersScrap metal dealers- Border crossingBorder crossing

Module IX.3 - Basic Concepts 14

Threat AssessmentThreat Assessment

As an example criteria for threat category II if: As an example criteria for threat category II if:

• Reactor power level > 2 and < 100 MW(th)Reactor power level > 2 and < 100 MW(th)

• Spent fuel requiring active coolingSpent fuel requiring active cooling

• A/D ratios 10 times the D2 values of material A/D ratios 10 times the D2 values of material that can be released that can be released

• Potential for criticality within 0.5 km of site Potential for criticality within 0.5 km of site boundary boundary

Module IX.3 - Basic Concepts 15

Threat AssessmentThreat Assessment

As an example criteria for threat category IV As an example criteria for threat category IV • Mobil source dose rates at 1 meter of > 10 Mobil source dose rates at 1 meter of > 10

mGy/hmGy/h• A/D value ratios > 1A/D value ratios > 1• Facilities with a significant probability of Facilities with a significant probability of

encountering an uncontrolled sourceencountering an uncontrolled source• Scrap metal dealersScrap metal dealers• Border crossingBorder crossing

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Threat AssessmentThreat Assessment

List typical threat categories for List typical threat categories for various practices:various practices: Industrial, medical and Industrial, medical and

scientific use scientific use Sealed sourcesSealed sources Fuel cycleFuel cycle ReactorsReactors TransportTransport Other Other

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Threat AssessmentThreat Assessment

List typical threat categories for List typical threat categories for various practicesvarious practices

ExamplesExamples

Hospital - possible category IIIHospital - possible category III severe deterministic effects severe deterministic effects

possible possible on site from on site from medical sources medical sources e. g. from teletherapy unit

Module IX.3 - Basic Concepts 18

Threat AssessmentThreat Assessment

Source exampleSource example Radiography cameras Radiography cameras

are in threat category IIIare in threat category III possible severe possible severe

deterministic effects if deterministic effects if control is lost control is lost

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Areas are also associated with a Threat Areas are also associated with a Threat CategoryCategory

Threat category Threat category Local jurisdiction Local jurisdiction

II Urgent protective actions in PAZ/UPZ for Urgent protective actions in PAZ/UPZ for

category Icategory I

IIII Urgent protective actions for PAZ for Urgent protective actions for PAZ for category II category II

IIIIII Emergency services for category III facilityEmergency services for category III facility

IVIV AllAll

VV With farming or food processing near With farming or food processing near category I or II facilitycategory I or II facility

Module IX.3 - Basic Concepts 20

Jurisdiction Jurisdiction

UPZ(Cat II, IV & V)

Facility(Cat I, II or III)

National border

Module IX.3 - Basic Concepts 21

Where to Get More InformationWhere to Get More Information

IAEA, Preparedness and Response for a IAEA, Preparedness and Response for a Nuclear or Radiological Emergency, Safety Nuclear or Radiological Emergency, Safety Standards Series No. GS-R-2, IAEA, Vienna Standards Series No. GS-R-2, IAEA, Vienna (2002)(2002)

IAEA, Method for Developing Arrangements IAEA, Method for Developing Arrangements for Response to a Nuclear or Radiological for Response to a Nuclear or Radiological Emergency, EPR-Method, IAEA, Vienna Emergency, EPR-Method, IAEA, Vienna (2003), (Updating TECDOC-953) (2003), (Updating TECDOC-953)