PAG MANUAL WORKSHOP

Presentation Transcript

PAG MANUAL WORKSHOP May 24, 2007 39th Annual National Conference on Radiation Control

PAG Workshop Elements Introduction PAG Update Summary Early Phase Intermediate Phase Drinking Water/Food PAGs Late Phase Conclusion/Summary

1992 EPA PAG Manual Included updates and modifications to past releases Based on Federal Guidance Report 11 philosophy (ICRP 26) Promised water and Late Phase PAGs

2007 Draft PAG Manual Clarifies the utilization of 1992 PAGs for episodes other than atomic power plant mischances Lowers anticipated thyroid measurements for KI Provides drinking water direction Includes direction for long haul site rebuilding Updates dosimetry from ICRP 26 to ICRP 60

What is a Protective Action Guide? PAG—An incentive against which to contrast the anticipated measurement with a characterized individual from an arrival of radioactive material at which a particular defensive activity to lessen or maintain a strategic distance from that dosage is justified. Anticipated measurement is a dosage that can be turned away by defensive activities.

Incident Response Phases Early Phase : Can last from hours to days until the discharge has ceased Intermediate Phase : Can last from seven days to months Late Phase : Can last from months to years

1992 Evacuation/Shelter 1-5 rem (10-50 mSv) KI 25 rem (250 mSv) thyroid measurement (grown-up) Worker 5, 10, 25+ rem (50, 100, 250+ mSv) Early Phase 2007 Evacuation/Shelter 1-5 rem (10-50 mSv) KI edge 5 rem (50 mSv) thyroid dosage (youngster) Worker 5, 10, 25+ rem (50, 100, 250+ mSv)

1992 Relocate populace ≥ 2 rem ( 20 mSv) (anticipated measurements) Apply measurement lessening systems < 2 rem (20 mSv) Food (FDA 1982) 0.5 rem (50 mSv) yearly dosage proportionate Drinking water Promised 2007 Relocate populace ≥ 2 rem (20 mSv) (anticipated dosage) Apply measurement decrease strategies < 2 rem (20 mSv) Food (FDA 1998): Act in view of most restricting of 0.5 rem (5 mSv) entire body or 5 rem (50 mSv) to most uncovered organ or tissue Drinking water 0.5 rem (5 mSv) first year CEDE Intermediate Phase

1992 1982 FDA direction NCRP 39 strategy Preventive PAG 0.5 rem entire body and 1.5 rem thyroid Emergency PAG 10 times higher, relies on upon effect Dose just, no action levels gave 2007 1998 FDA direction ICRP 56 & NRPB techniques One arrangement of PAGS 0.5 rem entire body measurements or 5 rem to most uncovered organ or tissue Dose and determined mediation levels (DILs) gave FDA Food PAGs

Drinking Water PAG 2007 Applicable to drinking water from any source EPA Safe Drinking Water Act levels after first year Doses will be significantly diminished in resulting years "Spanning dialect" to clarify FDA sustenance PAG (incorporates water) and EPA water PAG relationship 1992 Promised

Application to Terrorist Incidents Since 9/11, new danger of radiological fear mongering DHS reviewed the PAG Manual (Early and Intermediate PAGs) for application to RDDs or INDs and distinguished the requirement for Late Phase, or recuperation, direction Application of PAGs to IND occasions Scope and scale Priority on lifesaving and evasion of intense impacts Short reaction time allotment Unique aftermath rot bend Several tasks to address the requirement for extraordinary direction

Different Scenarios, Different Sequences Intermediate and Late Phase occasions will be comparative for RDD and NPP situations.

Late Phase Guidance 2007 DHS RDD/IND Consequence Management Workgroup drafted current direction ( January 3, 2006, Federal Register see) All radiological occasions secured (NPP/RDD/IND) Optimization 1992 Promised

Early Phase — Introduction Detailed portrayal of proposed PAG corrections Exposure pathways Crude figuring case for downwind dosage evaluate Evacuation and shielding Discuss KI organization Emergency specialist limits DCFs, DRLs Calculation case

Early Phase Initial Responses Notification of state as well as nearby experts Immediate departure/shielding (if important) before discharge data or estimations Monitoring of discharges and presentation rate estimations Estimation of dosage results Implementation of defensive activities in different zones, if vital

Early Phase Exposure Pathways Direct introduction Inhalation

Establish Exposure Patterns In the Early Phase, information are not adequate to precisely extend measurements Project dosage utilizing a mix of information and appraisals: Initial ecological estimations Source term gauges Previously watched barometrical transport under comparative meteorological conditions

Stability Class y A, B (light winds, sunlight) 2.0 C, D (wind>10 mph) 1.5 E, F (light winds@night) 1.0 Simple Exposure Rate Calculation If a site-particular model is not accessible, a straightforward technique can be utilized to compute the presentation rate at the tuft centerline at ground level (1 m stature). D 2 =D 1 (R 1/R 2 ) y D 1 and D 2 are estimations of presentation rates at the centerline of the tuft at separations R 1 and R 2 y is a steady that relies on upon environmental security

D 2 =D 1 (R 1/R 2 ) y D 2 =500(100/2000) 1 D 2 = 25 mR/hr Calculation Example The RDD detonated at 8:30 am (air soundness Class E, winds of around 5 miles for every hour). A radiation screen 100 meters from the impact site recorded fluctuating readings over the initial a hour that arrived at the midpoint of 500 mR/hr. What might the gauge of introduction rate be at a separation of 2 kilometers (closest government funded school) from the impact area? This data ought to be dissected in conjunction with crest source-term projections and airborne radioactivity focuses to figure out whether clearing or sanctuary set up is suitable. R 1 = 100 m R 2 = 2000 m D 1 = 500 mR/hr y = 1

Evacuation Same as 1992 PAG Manual Primary target is to keep away from introduction by moving far from the way of the crest Can be 100% powerful if finished before crest landing Exposure diminishment happens if departure goes before crest section

Sheltering Use of promptly accessible, close-by structures Sheltering choices ought to be founded on material discharged and presentation pathway For respectable gasses, outside presentation is the predominant pathway Consideration for inward breath pathway Ventilation control Seal airs out and openings shields after crest entry to ventilate

Potassium Iodide Actions FDA proposals for Early Phase KI organization is a multi-pronged approach: Children 0-18 years: Projected measurement to thyroid is 5 rem (50 mSv) or more noteworthy Pregnant and lactating ladies: Projected dosage to thyroid is 5 rem (50 mSv) or more prominent Adults up to 40 years: Projected dosage to thyroid is 10 rem (100 mSv) or more noteworthy Adults more than 40 years: Projected dosage to thyroid is more than 500 rem (5 Sv) [preventing hypothyroidism] EPA proposes a streamlined approach: Provide KI to open if 5 rem (50 mSv) youngster thyroid measurements anticipated This is a supplemental activity where clearing is the essential insurance

Guidance for Emergency Workers

Dose Conversion Factors Dose transformation elements (DCFs) are helpful for presentation to various radionuclides. H = Dose DCF = Dose Conversion Factor for radionuclide i C = Time-incorporated convergence of radionuclide i

DCP Example A mischance at a mechanical office brought about the arrival of radioactive iodine that was scattered into the air. A populated zone outside of the site limit encountered the accompanying radionuclide fixations: 2E-8 µCi/cm 3 Tm-170 DCP = 3.2E+4 4E-9 µCi/cm 3 Cs-134 DCP = 7.6E+4 1E-7 µCi/cm 3 I-131 DCP = 2.7E+4 (DCF in units of rem-cm 3 for every h-µCi, Table 2-5 in PAG Manual) H = ( 2E-8 x 3.2E+4 ) + ( 4E-9 x 7.6E+4 ) + ( 1E-7 x 2.7E+4 ) = 0.004 rem/hr 0.004 rem/hr x 96 hours = 0.4 rem For a four-day presentation period, a clearing PAG of 1 rem TEDE would not be surpassed.

Conclusion Questions or remarks on the Early Phase PAGs?

Break

Intermediate Phase — Introduction Detailed depiction of proposed PAG amendments Exposure pathways Relocation and dosage lessening Dose projection (with figuring illustrations) External (gamma) presentation Internal presentation (inward breath dosage) Exposure confines Longer term destinations for Intermediate Phase PAGs

Intermediate Phase Period that starts after the source and discharges have been brought under control Environmental estimations are accessible as bases for choices May cover Early and Late Phases Exposure pathways are basically entire body outside measurement and inner dosage from inward breath or ingestion

Protective Actions

Response Areas Priorities Protect all people from measurements that could bring about intense wellbeing impacts Establish a system for migration Recommend straightforward decon strategies and investing however much energy inside as could reasonably be expected Evacuation Area Relocation Area Deposition Area Shelter Area Plume Direction

Sequence of Events Identify high measurement rate ranges Relocate populace from high dosage rate territories Allow return of evacuees to noncontaminated zones Establish movement regions Establish methods for diminishing presentation of nonrelocated populace Perform itemized ecological checking Decontaminate basic offices and courses Begin recuperation exercises

Example — Total Dose Due to Deposition

External Dose

Inhalation Dose

Example: 239 Pu or 137 Cs in RDD What are the aggregate measurement parameters for the principal year for stored tainting coming about because of the situations where a RDD has kept either 239 Pu or 137 Cs on a populated territory (accept weathering)?

239 Pu 1 st year time stage TDP_Dp = 6.73E-5 mrem per pCi/m 2 Initial Dose Rate External Exposure Factor = 4.43E-12 mrem/hr per pCi/m 2 137 Cs (with 137 Ba) 1 st year time stage TDP_Dp = 4.77E-5 mrem per pCi/m 2 Initial Dose Rate External Exposure Factor = 6.01E-9 mrem/