AUTORIDAD REGULATORIA NUCLEAR (ARN) Radon Measurements in Argentina Juan Pablo Bonetto a, Analia Canoba, Fabio López Gerencia de Apoyo Científico técnico ARN a E-mail: jbonetto@arn.gob.ar
Introduction National Atomic Energy Comission (CNEA) 1997 - Nuclear Activity National Law () CNEA and others: Regulated institutions ARN Independent body: regulation and control of the nuclear activity in Argentina, in relation with radiological and nuclear safety, physical protection and safeguards. radiochemical, physical and biological laboratories Assessment to inspectorate Environmental control (NORM advicing, but no regulation) (Radon measurements Lab)
Measurement techniques Kernforschungszentrum Karlsruhe (KfK) provided Makrofol material, holders, etching equipment and training in the early s. 1 m 3 acrylic glove-box KFK + CR-39 detector Big cup + Makrofol detector Makrofol Lucas cell with Ludlum flask counter and scaler ratemeter. mm Air inlet Filter Air inlet 5 mm Makrofol 5 mm
Measurement techniques SST Electret Short-term measurements (-7 days) Activated charcoal vial Long-term measurements (3- months) Radosys system (RSKS detector)
Radon in dwellings of Argentina Province Average Rn concentration (Bq.m -3 ) Max Number of measurements Meas. method a Mendoza 9 5 1 1,,3, Corrientes 7 19 1 Buenos Aires 33 39 1,,3, Chaco 9 13 35 1 Santa Fe 3 119 1 1 San Luis 9 1, 3, Chubut 7 3 1,3, Sant. del Estero 7 1 Rio Negro 35 1 73 1, Córdoba 5 35 39 1, Entre Ríos 79 137 17 Tierra del Fuego 7 7 Salta 7 17 Santa Cruz 11 1 193 to 11 Earliest meas.: Lucas Cells Latest: CR-39 At first: dwellings near U mining/milling sites (Mendoza, Córdoba) and dwellings of relatives & friends (Buenos Aires) Later: other interested parties included (Chubut, Santa Cruz) Argentina (weighted) 317 a 1- Makrofol, - SST Electrets, 3- Activated charcoal, - CR-39.
Radon in dwellings of Argentina Frequency 1 9 7 5 3 1 1 measurements F =,37 1 1 1 1 Rn- concentration in dwellings (Bq m -3 ) Lots of experience gained 3 Bq m -3 (under revision) Higher... but, only a Radiological Safety Basic Norm AR 1.1.1 rev 3 Screening Lots of things to correct Selection of cities and dwellings, number of measurements. More representative methods. Data collected (construction materials, rooms measured, flooring, etc) and data analysis. Logisitcs
Radon in U mining/milling facilities But, by law, our main duty is controlling nuclear fuel cycle facilitites Occupational monitoring (by request of inspectorate) U mining/milling Environmental monitoring Revise and approve operators environ. monitoring plans Design and carry out our own verification monitoring Rn concentration in surrounding dwellings (and comparison with sites perimeter values) Rn exhalation from tailings Verify tailings condition Compare pre- vs post-remediation rates Dose modelling
1 Radon exhalation rate - Facility A 1 1 97_1 97_ 97_3 97_ 99_1 99_ 99_3 1_1 1 1 _ 3_1 3_ 5_1 5 1 7_1 _1 9_1 1_1 11_1 1_1 13_1 13_ B q.m -.s -1 1 1 1 Radon exhalation rate - Facility B 95_1 95_ 95_3 9_1 9_ 9_3 9 1 3 _1 1 _1 1 1_1 1_1 Bq.m -.s -1 1 Radon exhalation rate - Facility C 1 1 95_1 95_ 95_3 9_1 9_ 9_3 9_ 9_5 9_1 9_ 9_3 9_ 99_1 99_ 99_3 _1 3 1_1 1 1 3 3_1 3_ 3_3 5_1 5 1 _ 7_1 _1 9_1 1_1 11_1 1_1 13_1 Bq.m -.s -1 1 1 1 Radon exhalation rate - Facility D 9_1 9_1 9 1 _ 5_1 1_1 B q.m -.s -1 Exhalation rates from U tailings
1 Radon exhalation rate - Facility E 1 1 9_1 99_1 99 1 _ 7_1 1_1 Bq.m -.s -1 1 1 1 Radon exhalation rate - Facility F 3_1 _1 13_1 B q.m -.s -1 1 Radon exhalation rate - Facility G 1 1 9_1 9_ 97_1 9_1 9_ 9_3 9 1 _ 3_1 7_1 Bq.m -.s -1 1_1 1 1 1 Radon exhalation rate - Facility H 97_1 97 1 _ 7_1 1_1 Bq.m -.s -1 Exhalation rates from U tailings
Exhalation rates from U tailings Values relatively stable over the years Variations mainly due to short-period measurements ( hs) affected by soil moisture content? (Facility C: tailings disturbance for relocation) Higher values than US EPA recommended value of.7 Bq m - s Non-remediated tailings: Natural vegetative cover in some cases Higher values in tailings from higher U content mineral (facility H Vs Facility D)
Radon in perimeter of mining/milling facilities Determine tailings Rn influence on nearby dwellings Long-period passive detectors CR-39 with KfK holders RSKS detectors (Radosys) Outline the facilities perimeters, select sampling points and locate nearby dwellings. Locate sources of Rn within the site, record wind direction and frequency, estimate distance from sampling points to source. Determine high indoor values and compare with outside-dwellings values. Compare also outside-dwellings values with perimeter and source values.
Radon in perimeter of mining/milling facilities Facility B (Far from population) Radon in air (Bq m -3 ) * Sampling point 1 13 Sampling point 1 13 P1 53 3.3 In Na Na D5 P 3 3 Out Na <DL P3 1 <DL In 15 <DL D P 1 <DL Out 1 9. D1 In 35 9.3 In 3 15 D7 Out 7 <DL Out 1 <DL D In 79 1.1 In 3.7 D Out 9 <DL Out 7 <DL D3 In Na 1.5 In 31 <DL D9 Out Na <DL Out 19 <DL D In 5. In 7 <DL D1 Out 39 1.1 Out <DL P = Perimeter; D = Dwelling; Na = Not available; DL = Detection Limit: 9 Bq m -3 Closer to source Facility C (Close to population) Radon in air (Bq m -3 ) * Sampl. point 1 13 Sampl. point 1 13 P1 31 In 3. D5 P 7 Out Na 1.9 P3 33 7.5 In 17. D P <DL 3.7 Out Na <DL P5.3 In 7. D7 P 57 5. Out 5.5 P7 <DL 1.3 In Na 33. D P 13 <DL Out <DL <DL D1 In Na Na In Na 11 D9 Out Na Na Out <DL <DL D In 1 1 In 11. D1 Out 71 1 Out Na <DL D3 In Na 17. In. D11 Out Na 1. Out Na <DL D In Na 11.3 In 1 1.7 D1 Out Na <DL Out na <DL P = Perimeter; D = Dwelling; Na = Not available; DL = Detection Limit: 9 Bq m -3
NORM measurements ARN is not the competent authority regarding NORM regulation ( but has experience on the subject) NORM survey project Workers exposure to NORM in the oil and gas industry, non-u underground mines, tourist caverns and thermal spas. Canoba AC (1) NORM survey in Argentina. Annals of the ICRP 1:35-37
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