Intervention for Chronic and Emergency Exposure Situations Module IX Basic Concepts for Emergency preparedness and Response for a nuclear accident or radiological emergency Emergency Threat Categories Lecture IAEA Post Graduate Educational Course in Radiation Protection and Safety of Radiation Sources

Module IX.3 - Basic Concepts2 Assessment of Threats l The nature and extent of emergency arrangements have to be commensurate with the potential magnitude and nature of the hazard associated with the facility or activity l The threat assessment must be periodically reviewed to take into account changes in to the threats within and outside the country and the experience and lessons from previous events involving relevant practices and sources

Module IX.3 - Basic Concepts3 Assessment of Threats (cont’d) l The threat assessment has to identify installations, sources, practices, on-site areas, off-site areas or locations for which nuclear or radiological emergencies could warrant: n precautionary urgent protective actions to prevent severe deterministic health effects n urgent protective actions to reduce stochastic effects n agricultural and ingestion countermeasures and long term protective measures n protection for the workers undertaking an intervention

Module IX.3 - Basic Concepts4 Threat Categories l Nuclear and radiation threats are grouped according to the five threat categories n Categories I through IV represent decreasing levels of threat and therefore decreasing emergency preparedness and response requirements n Category IV is the minimum level of threat assumed to exist everywhere and thus always applies possibly along with other categories n Category V is a special category and may apply along with other categories

Module IX.3 - Basic Concepts5 Threat Category I l Nuclear installations for which events that could give rise to severe deterministic health effects off-site are postulated or have occurred in similar installations, including very low probability events

Module IX.3 - Basic Concepts6 Threat Category II l Installations for which events that can give rise to off-site doses warranting urgent protective actions consistent with international standards are postulated or have occurred in similar installations n This category (as opposed to category I threats) has no credible events postulated that could give rise to off- site doses resulting in severe deterministic health effects

Module IX.3 - Basic Concepts7 Threat Category III l Installations for which events that could give rise to doses on-site resulting in severe deterministic health effects are postulated or have occurred within similar installations n This category (as opposed to category II threats) has no credible events postulated for which urgent off-site protective actions are warranted

Module IX.3 - Basic Concepts8 Threat Category IV l Minimum level of threat assumed for all countries and jurisdictions

Module IX.3 - Basic Concepts9 Threat Category V l Areas that have a significant probability of being contaminated to levels necessitating food restrictions consistent with international standards as a result of events at installations in threat categories I or II, including installations in other countries

Module IX.3 - Basic Concepts10 Introduction - Requirements (GS-R-2) Are Established for Threat Categories Threat Category Radiological Threat I Severe deterministic health effects off-site II Warranting urgent protective actions off-site, deterministic health effects on-site III No urgent protective actions off-site are warranted, severe deterministic health effects on-site IV Minimum level of threat – all countries V Food contamination due to transboundary contamination necessitating food restrictions

Module IX.3 - Basic Concepts11 The Safety Requirements (GS-R-2) l Sets requirements for dangerous sources and defines: n “Dangerous source” “could, if not under control, give rise to exposure sufficient to cause severe deterministic effects” n “Severe deterministic effect” that “is fatal or life threatening or results in a permanent injury that decreases the quality of life”

Module IX.3 - Basic Concepts12 Severe Deterministic Effect Reduces the quality of life

Module IX.3 - Basic Concepts13 Threat Assessment Threat categories of facilities and practices based on: - Reactor power levels - Spent fuel inventories - Activity/D value ratios - Dose rates at 1 meter - Potential for criticality - Probability of encountering an uncontrolled source an uncontrolled source - Scrap metal dealers - Border crossing

Module IX.3 - Basic Concepts14 Threat Assessment As an example criteria for threat category II if: Reactor power level > 2 and 2 and < 100 MW(th) Spent fuel requiring active cooling Spent fuel requiring active cooling A/D ratios 10 times the D2 values of material that can be released A/D ratios 10 times the D2 values of material that can be released Potential for criticality within 0.5 km of site boundary Potential for criticality within 0.5 km of site boundary

Module IX.3 - Basic Concepts15 Threat Assessment As an example criteria for threat category IV Mobil source dose rates at 1 meter of > 10 mGy/h Mobil source dose rates at 1 meter of > 10 mGy/h A/D value ratios > 1 A/D value ratios > 1 Facilities with a significant probability of encountering an uncontrolled source Facilities with a significant probability of encountering an uncontrolled source Scrap metal dealers Scrap metal dealers Border crossing Border crossing

Module IX.3 - Basic Concepts16 Threat Assessment l List typical threat categories for various practices: n Industrial, medical and scientific use n Sealed sources n Fuel cycle n Reactors n Transport n Other

Module IX.3 - Basic Concepts17 Threat Assessment l List typical threat categories for various practices Examples l Hospital - possible category III n severe deterministic effects possible on site from medical sources se. g. from teletherapy unit

Module IX.3 - Basic Concepts18 Threat Assessment l Source example l Radiography cameras are in threat category III n possible severe deterministic effects if control is lost

Module IX.3 - Basic Concepts19 Areas are also associated with a Threat Category Threat category Local jurisdiction I Urgent protective actions in PAZ/UPZ for category I II Urgent protective actions for PAZ for category II III Emergency services for category III facility IVAll V With farming or food processing near category I or II facility

Module IX.3 - Basic Concepts20 Jurisdiction

Module IX.3 - Basic Concepts21 Where to Get More Information l IAEA, Preparedness and Response for a Nuclear or Radiological Emergency, Safety Standards Series No. GS-R-2, IAEA, Vienna (2002) l IAEA, Method for Developing Arrangements for Response to a Nuclear or Radiological Emergency, EPR-Method, IAEA, Vienna (2003), (Updating TECDOC- 953)