1 / 52

Assessing Prolonged Exposures. The DRL Approach

8th Meeting of the EMRAS Tritium & C-14 Working Group. May 30 - June 1, 2007 - Bucharest, Romania. Assessing Prolonged Exposures. The DRL Approach. Bogdan Vamanu, MSc Valentin Acasandrei, MSc Dan Vamanu, PhD. National Institute for Physics and Nuclear Engineering, Bucharest, Romania.

dotty
Download Presentation

Assessing Prolonged Exposures. The DRL Approach

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 8th Meeting of the EMRAS Tritium & C-14 Working Group May 30 - June 1, 2007 - Bucharest, Romania Assessing Prolonged Exposures. The DRL Approach Bogdan Vamanu, MSc Valentin Acasandrei, MSc Dan Vamanu, PhD National Institute for Physics and Nuclear Engineering, Bucharest, Romania Department of Life- and Environmental Physics

  2. SITING SITING SITING SITING AUTHORIZATION MONITORING routine (tehnologically-normal) environmental releases resulting in prolonged exposures of the radiation workers (onsite) and the population (outside) DRL

  3. The DRL is defined as the radioactive release over a year that would expose members of the critical group to the regulatory dose limit. In general, nuclear power plants set their operating targets for releases of each radionuclide below 1% of the DRL. Technical Reports Series No. 42I Management of Waste Containing Tritium and Carbon-14 - IAEA radioactive release over a year critical group regulatory dose limit releases of each radionuclide below 1% of the DRL

  4. Derived Release Limit (DRL): A limit imposed by the AECB on the release of a radioactive substance from a licensed nuclear facility such that compliance with the DRL gives reasonable assurance that the regulatory dose limit is not exceeded. Radioactive Release Data from Canadian Nuclear Generating Stations 1990 to 1999. INFO-0210/REV. 10 Canadian Nuclear Safety Commission, October 2000 A limit imposed licensed nuclear facility reasonable assurance

  5. From 2002 to 2004, the annual public dose was calculated using emissions to air and emissions to sewer in a worst case scenario model (i.e., a person living at the fence line 24 hours per day, 365 days per year breathing perimeter air and drinking sewer water at ICRP “reference man” recommended rates). Information and Recommendations from Canadian Nuclear Safety Commission Staff In the Matter of Zircatec Precision Industries Inc. emissions to air emissions to sewer fence line perimeter

  6. When it approved the DRLs for each nuclear generating station, the AECB considered the environmental pathways through which radioactive material could reach the most exposed members of the public after being released from the facility. The most exposed members of the public are called the “critical group.”They are defined as those individuals who are expected to receive the highest dose of radiation because of such considerations as their age, diet, lifestyle and location. Radioactive Release Data from Canadian Nuclear Generating Stations 1990 to 1999. INFO-0210/REV. 10 Canadian Nuclear Safety Commission, October 2000 environmental pathways age, diet, lifestyle location

  7. Problem Statement What is… … that… Radioactive release over a year … is allowed to… Critical group Regulatory dose limit … so that the total dose aquired by an individual from the … Releases of each radionuclide below 1% of the DRL A limit imposed Licensed nuclear facility … selected based on … Reasonable assurance Emissions to air Emissions to sewer … , via all… Fence line Perimeter … would not exceed ( ) the… Environmental pathways ? Age, diet, lifestyle Location

  8. DRL What is… Radioactive release over a year … that… Licensed nuclear facility … is allowed to… Emissions to sewer Emissions to air What is the radioactive release over a year (Bq/year) that a nuclear facility is allowed to emit to environment (air, surface water, sewer) so that the total dose acquired by an individual (total effective dose equivalent – TEDE) from the critical group would not exceed (within reasonable assurance) the regulatory dose limit? … so that the total dose aquired by an individual from the … Releases of each radionuclide below 1% of the DRL A limit imposed Critical group … selected based on … Age, diet, lifestyle Location Perimeter Fence line … , via all… Environmental pathways … would not exceed ( ) the… Reasonable assurance Regulatory dose limit ?

  9. Ensure that the facility IS operated so that • Taking into account • All the individual installations, • All the nuclides released to environment, • All exposure pathways, The TOTAL EFFECTIVE DOSE EQUIVALENT – TEDE, POTENTIALLY acquired by an individual from the CRITICAL GROUP be less or equal to A FRACTION, P, NEGOCIABLE, of the regulatory dose limit. ! ?

  10. ?

  11. (…) provides a practical generic methodology for assessing the impact of radionuclide discharges in terms of the resulting individual and collective radiation doses. (…) procedure for application to radioactive discharges and is addressed to the national regulatory bodies and technical and administrative personnel responsible for performing environmental impact analyses.

  12. Special cases: 3H, 14C Specific Activity Models…

  13. INTERNATIONAL COMMISSION ON RADIOLOGICAL PROTECTION, Age-dependent Doses to Members of the Public from Intake of Radionuclides, Part 5, Compilation of Ingestion and Inhalation Dose Coefficients, ICRP Publication No. 72, Pergamon Press, Oxford and New York (1996). WATER AIR 3H 3H2O the dose rate (Sv/a) for 3H to the body of a representative member of the critical group; the steady state concentration of 3H in atmospheric water vapour (Bq/L) at location x1 resulting from airborne releases, the fraction of the total water intake that is derived from atmospheric water vapour at location x1 steady state concentration of 3H in water at location x2 resulting from releases to the aquatic environment (Bq/L) the concentration of 3H in air at location x1 (Bq/m3) the absolute humidity of the atmosphere the fraction of the total water intake of the potentially exposed person that is derived from water at location x2 that has been contaminated with aquatic discharges of tritiated water the dose rate conversion factor (Sv/a per Bq/L of human body water content).

  14. KILLOUGH, G.G., ROHWER, P.S., A new look at the dosimetry of 14C released to the atmosphere as carbon dioxide, Health Phys. 34 (1978) 141–159. 14C 14CO2 the effective dose rate (Sv/a) the specific activity (Bq 14C per gram of C) to which food products at location x will be chronically exposed the fraction of total dietary carbon derived from location x by the representative member of the critical group the effective dose rate factor that relates the annual dose rate (Sv/a) to the concentration of 14C per gram of carbon in people (Bq/g). the concentration of 14C in air at location x (Bq/m3) the concentration of airborne carbon, assumed to be 1.8 × 10–1 g/m3, corresponding to an average atmospheric CO2 concentration of 330 ppm

  15. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. 3 Wrapping-up DRL{g; r, p, s, n} - g: critical group identifier; - r: receptor identifier; - p: pathway identifier; - s: source identifier; - n: nuclide The Conformity criterion* - L(p,s,n): current emission level (Bq/s); - g: critical group identifier; - r: receptor identifier; - p: pathway identifier; - s: source identifier; - n: nuclide

  16. Illustrative Examples Example 1 One Source, One Receptor, One Nuclide Example 2 Multiple Sources, Multiple Receptors, Multiple Nuclides The cases are purely fictitious; the assessment is performed in a ‘blind run’ philosophy, using model’s default input values.

  17. Example 1One Source, One Receptor, One Nuclide No. of Sources: 1 No. of Receptors: 1 Released Nuclide(s):3H Release Pathway: air

  18. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 1One Source, One Receptor, One Nuclide Site Map Description: Northern Latitude (deg): 44.3592277 Western Longitude (deg): 26.0336333 Latitude Span (deg): 0.0185129 Longitude Span (deg): 0.0311861

  19. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 1One Source, One Receptor, One Nuclide Source #1 Latitude (deg.): 44.3514298 Longitude (deg.): 26.0473757

  20. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 1One Source, One Receptor, One Nuclide RECEPTOR #1 Latitude (deg): 44.3565349 Longitude (deg): 26.0428868

  21. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, p, s, n} Example 1One Source, One Receptor, One Nuclide Source: Source #1 Receptor: Receptor #1 Source to Receptor Distance (km): 0.67131475 Receptor Sector No. (1 to 12): 12 Nuclide: H-3 Release to AIR DOSE CRITERIA Maximum Admissible Dose from Source, to population, (Sv in 1a): 0.00001 Maximum Admissible Dose from Source, to workers (Sv in 1a): 0.00005 ======================== D.40. The DERIVED RELEASE LIMIT based on Infant Dose (Bq/s): 923077.477 D.41. The DERIVED RELEASE LIMIT based on Adult Dose (Bq/s): 923077.477 D.42. The DERIVED RELEASE LIMIT based on Workers Dose (Bq/s): 4615387.38 ======================== C O N C L U S I O N D.43. THE RECOMMENDED DERIVED RELEASE LIMIT FOR THE ......ANNUAL AVERAGE DISCHARGE RATE TO ATMOSPHERE of H-3, Qi (Bq/s), is: 923077.477 ......The consequent admissible Total Annual Discharge to Atmosphere ..... of H-3 is: 2.91101713e13 Bq, i.e 786.761387 Ci. ......DERIVED RELEASE LIMIT FACTOR, Infants, DRLFi (1/Sv): 9.23077477e10 ......DERIVED RELEASE LIMIT FACTOR, Adults, DRLFa (1/Sv): 9.23077477e10

  22. 3 Wrapping-up The Conformity criterion* Example 1One Source, One Receptor, One Nuclide

  23. What is it good for… AUTHORIZATION OPERATION REJECTED Estimated Release Quantity of 3H 3.5 * 1013 [Bq per a] C[1,1] = 1.2023288

  24. AUTHORIZATION OPERATION REJECTED Estimated Release Quantity of 3H APPROVED 3.5 * 1013 [Bq per a] 2.3 * 1013 [Bq per a] C[1,1] = 1.2023288 C[1,1] = 0.7901018

  25. AUTHORIZATION OPERATION REJECTED Current Release Status of 3H 2.51546 * 1013 [Bq] 0.5 * 1013 [Bq] 3.01546 * 1013 C[1,1] = 1.0358784

  26. AUTHORIZATION OPERATION REJECTED Current Release Status of 3H 2.51546 * 1013 [Bq] APPROVED 0.5 * 1013 [Bq] 0.3 * 1013 [Bq] 2.81546 * 1013 C[1,1] = 1.035784 C[1,1] = 0.9671739

  27. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides No. of Sources: 2 No. of Receptors: 3 Released Nuclide(s):

  28. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides Source #1 Latitude (deg.): 44.3514298 Longitude (deg.): 26.0473757 Source #2 Latitude (deg.): 44.3507566 Longitude (deg.): 26.0489113

  29. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides Source #1 Latitude (deg.): 44.3514298 Longitude (deg.): 26.0473757 Source #2 Latitude (deg.): 44.3507566 Longitude (deg.): 26.0489113

  30. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides RECEPTOR #2 Latitude (deg): 44.3528043 Longitude (deg): 26.0392247 RECEPTOR #1 Latitude (deg): 44.3565349 Longitude (deg): 26.0428868 RECEPTOR #3 Latitude (deg): 44.3432393 Longitude (deg): 26.051077

  31. 1 Pre-Assessment Build the Situation Map Acquire image maps; Geo-reference the maps; Build source pattern; Build receptor pattern. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides

  32. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n)

  33. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;10,1,a,n)

  34. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;10,1,a,n) DRL(g;6,1,a,n)

  35. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;12,2,a,n) DRL(g;10,1,a,n) DRL(g;6,1,a,n)

  36. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;12,2,a,n) DRL(g;10,1,a,n) DRL(g;11,2,a,n) DRL(g;6,1,a,n)

  37. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;12,2,a,n) DRL(g;10,1,a,n) DRL(g;11,2,a,n) DRL(g;6,1,a,n) DRL(g;7,2,a,n)

  38. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides DRL(g;12,1,a,n) DRL(g;12,2,a,n) DRL(g;10,1,a,n) DRL(g;11,2,a,n) DRL(g;6,1,a,n) DRL(g;7,2,a,n)

  39. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides

  40. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides

  41. 2 Assessment For each critical group, source, nuclide, receptor, and pathway - compute the DRL. DRL{g; r, s, p, n} Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides

  42. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides 3 Wrapping-up The Conformity criterion* Receptor #1

  43. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides 3 Wrapping-up The Conformity criterion* Receptor #2

  44. Example 2Multiple Sources, Multiple Receptors, Multiple Nuclides 3 Wrapping-up The Conformity criterion* Receptor #3

  45. OPERATION 131I 2B Relesed: 210000 Bq Receptor #1 Current Release Status of The Compund [Receptor #1] 0.75 All but 131I, Source #1 L(1,a,131I)=4000000 Max adm. 16830586.3 131I, Source #1 [Bq] 0.23766 Receptor #2 Current Release Status of The Compund [Receptor #2] 0.65 All but 131I, Source #1 L(1,a,131I)=3000000 Max adm. 16830545.7 131I, Source #1 0.17824 Receptor #3 Current Release Status of The Compund [Receptor #3] 0.70 All but 131I, Source #1 131I, Source #1 L(1,a,131I)=4000000 Max adm. 16832996.0 0.23763

  46. OPERATION 131I 2B Relesed: 210000 Bq Wind from Source #1 towards Receptor #1 (sector 12) Receptor #1 Current Release Status of The Compund [Receptor #1] 0.75 All but 131I, Source #1 >1 L(1,a,131I)=4210000 Max adm. 16830586.3 131I, Source #1 [Bq] 0.25014 Receptor #2 Current Release Status of The Compund [Receptor #2] 0.65 All but 131I, Source #1 L(1,a,131I)=3000000 Max adm. 16830545.7 131I, Source #1 0.17824 Receptor #3 Current Release Status of The Compund [Receptor #3] Res 0.25010 0.70 All but 131I, Source #1 131I, Source #1 L(1,a,131I)=4000000 Max adm. 16832996.0 0.23763

  47. OPERATION 131I 2B Relesed: 210000 Bq Wind from Source #1 towards Receptor #1 (sector 12) Wind from Source #1 towards Receptor #2 (sector 10) Receptor #1 Current Release Status of The Compund [Receptor #1] 0.75 All but 131I, Source #1 >1 L(1,a,131I)=4210000 Max adm. 16830586.3 131I, Source #1 [Bq] 0.25014 Receptor #2 Current Release Status of The Compund [Receptor #2] 0.65 All but 131I, Source #1 <1 L(1,a,131I)=3210000 Max adm. 16830545.7 131I, Source #1 0.19072 Receptor #3 Current Release Status of The Compund [Receptor #3] 0.70 All but 131I, Source #1 131I, Source #1 L(1,a,131I)=4000000 Max adm. 16832996.0 0.23763

More Related