CHARACTERISATION OF NON-NUCLEAR WASTE AND ITS SOURCES

Transcription

1 CHARACTERISATION OF NON-NUCLEAR WASTE AND ITS SOURCES NEA Workshop on the Management of Non- Nuclear Radioactive Waste 2-4 May 2017 Presented by: Dr. Douglas Chambers May 2017

2 TYPES OF NON-FUEL CYCLE RAD WASTES NORM Industrial Medical and Research Arcadis

3 Mining and Mineral Processing All soils and minerals have natural radioactivity In some cases natural levels can be elevated, in others, levels can be increased by processing Elevated radioactivity levels can affect operations and mine closure Arcadis

4 What is NORM? Naturally Occurring Radioactive Material, not subjected to regulations under the Atomic Energy Act, disturbed or altered from natural settings, or present in a technologically enhanced state due to human activities, which may result in a relative increase in radiation exposure and risk to public above background radiation level. [HPS] Arcadis

5 Risks from NORM Minerals In the majority of situations, the NORM concentrations do not pose potential problems to the environment or human health But Processing of ores can lead to further enhancement of the radioactivity in the products, by-products, residues or wastes Arcadis

6 TENORM The physical, chemical, radiological properties and concentrations of NORM have been altered such that there exists a potential for: Redistribution and contamination of environment media (soil, water, and air); Increased environmental mobility in soils and groundwater; Incorporation of elevated levels of radioactivity in products and construction material; Improper disposal or use of disposal methods that could result in unnecessary and relative high exposure to individuals and populations via any environmental pathway medium. [HPS] Arcadis

7 NORM Sources Identified by UNSCEAR 2008 Annex B Metal mining and smelting Phosphate industry Coal mining and power production from coal Oil and gas drilling Rare earth and titanium oxide industries Applications of radium and thorium (historic contaminated sites) Other water treatment and other NORM wastes Arcadis

8 Concentration Ranges of Uranium and Thorium Series Radionuclides Non-optimum use of regulatory resources Optimum use of regulatory resources Uranium ores, U-238 Monazite, Th-232 Pyrochlore, Th-232 Zircon, U-238 Ilmenite, Th-232 Rutile, U-238 Phosphates, U-238 Bauxite Other metal ores, U-238 or Th-232 Soil, U-238 Soil, Ra-226 Data from UNSCEAR 2000 After Wymer, 2008 Soil, Th Activity concentration (Bq/g) Arcadis

9 Phosphogypsum Stacks More than 10 9 tons of PG in North America Can be managed as waste or as useful by-product Current world-wide initiative Stack Free to develop safe uses of PG Arcadis

10 Phosphate NORM Main contributors to dose related to phosphate: external gamma radiation from Ra-226 in soil inhalation of radon (and RDP) Radioactivity was already existing and its distribution has changed. At some locations more accessible for exposure Arcadis

11 Tanatalum Raw Materials All electronic devices with capacitors contain tanatalum Tantalum raw materials contain radioactivity uranium and thorium Denial of shipment of raw materials to processing sites can be a problem An IAEA CRP examined transport of NORM materials Arcadis

12 Activity Concentrations (Bq/g) in Tantalum Raw Materials Radionuclide Material Type Number of Shipments Mean (Bq/g) Max. (Bq/g) Proportion > 10 Bq/g (%) Th-232 Slag Th-232 Tantalite U-238 Slag U-238 Tantalite Total Slag Total Tantalite Arcadis 2017

13 Radionuclides from Coal Power Plants Naturally Occurring Radioactive Materials (NORM) are part of the mineral content and become concentrated in the ash When concentrated, the NORM becomes TENORM - Technologically Enhanced Naturally Occurring Radioactive Material gas phase as airborne effluents (primarily radon, some particulates) solid combustion products (U, Th, Ra and progeny) Average ash yield of coal burned ~10% by weight quantity depends on mineral content of coal and boiler type (varies from 3-30%) Accordingly, the concentration of radionuclides in coal ash TENORM can be 10x greater than in the coal Arcadis

14 TENORM in Coal Ash ppm Uranium (7-20 pci/g) similar to granite and phosphate rocks and black shales TENORM Activity in Coal Ash Arcadis

15 NORM in Oil and Gas Industry (1) NORM present at varying concentrations in formations from which oil and gas are produced Most NORM contains radionuclides from uranium and thorium decay chains Primary radioactive isotopes of concern include: - Radium-226 (Ra-226) - Radium-228 (Ra-228) - Radon-222 (Rn-222) - Lead-210 (Pb-210) - Polonium-210 (Po-210) Arcadis

16 NORM in Oil and Gas Industry (2) Radioactive elements brought to surface with production fluids and typically stay with water phase Radon follows gas production stream Longer-lived radon progeny found in pumps, tanks and product lines associated with ethane/propane processing During pigging, pig scrapes along interior wall of pipeline and material pushed in front of pig and collected by pig trap Resulting material in trap may contain elevated levels of NORM from U-238 decay series, specifically Pb-210, Po-210 & Bi-210 Arcadis

17 NORM in Oil and Gas Industry (3) Arcadis

18 USEPA (1973) Radon Concentration in NG Distribution Line Radon-222 Concentration (pci/l) Area Average Range Chicago New York City Denver West Coast Colorado Nevada New Mexico Houston Overall 23 Arcadis

19 Plating and Implications (1) Arcadis

20 Plating and Implications (2) Lead 210 will plate onto surfaces in natural gas, ethane, and propane lines Polonium 210, Bismuth 210 accumulate over time as Lead 210 decays All three radionuclides will be difficult to detect from the outside of equipment and pipes Arcadis

21 NORM in Oil and Gas Industry Arcadis

22 Shale Plays in Lower 48 States Arcadis

23 Marcellus Shale - Observations Treated frac H 2 0 sludge: mr/h Treated frac H 2 0 sludge: BG - 3,000 pci/g Gas Well Environs, 45 Pennsylvania sites Background: 9.0 mr/h Well Pads: 8.7 mr/h Well Pits: 9.3 mr/h [some mr/h] Radon in Natural Gas: 37 pci/l [1-79 pci/l] Arcadis

24 Source: Radiation Level [pci/g] low average high Soils of the United States 0.2 NA 4.2 Geothermal Energy Production Wastes (fact sheet) Oil and Gas Production Wastes (fact sheet) Produced Water [pci/l] 0.1 NA 9,000 Pipe/Tank Scale <0.25 <200 >100,000 NORM Waste and By-products Drinking Water Treatment Wastes (fact sheet) Treatment Sludge [pci/l] ,686 Treatment Plant Filters NA 40,000 NA Waste Water Treatment Wastes (fact sheet) Treatment Sludge [pci/l] Treatment Plant Ash [pci/l Aluminum Production Wastes (fact sheet) Ore (Bauxite) 4.4 NA 7.4 Product 0.23 Production Wastes NA NA Coal Ash (fact sheet) Bottom Ash Fly Ash Copper Mining and Production Wastes (fact sheet) Note: Unless otherwise noted, the radiation level of each waste is shown in the units pci/gram. For comparison purposes, the average level of radium in soil ranges from less than 1 to slightly more than 4 pci/gram. "NA" indicates data is not available Arcadis

25 Source: Radiation Level [pci/g] low average high Fertilizer and Fertilizer Production Wastes (fact sheet) Ore (Florida) Phosphogypsum Phosphate Fertilizer Gold and Silver Mining Wastes (fact sheet) Rare Earths (Monazite, Xenotime, Bastnasite) Extraction Wastes (fact sheet) 5.7 NA 3224 NORM Waste and By-products cont d Titanium Production Wastes (fact sheet) Rutile 19.7 NA Ilmenite NA 5.7 Wastes Uranium Mining Wastes (fact sheet) Uranium Mining Overburden low Uranium In-Situ Leachate Evaporation Pond Solids Zircon Mining Wastes (fact sheet) Note: Unless otherwise noted, the radiation level of each waste is shown in the units pci/gram. For of radium in soil ranges from less than 1 to slightly more than 4 pci/gram. "NA" indicates data is not available Wastes Arcadis

26 NORM Regulation in Canada NORM is exempt from the application of the Nuclear Safety and Control Act (NSCA). Except: when NORM is associated with the development, production or use of nuclear energy. when NORM is imported into Canada or exported from Canada. the transport of NORM when the specific activity is greater than 70 Bq/g (70 kbq/kg). Arcadis

27 NORM Regulation in Canada cont d Arcadis 2017 NORM is regulated by the provincial and territorial governments, each having its own specific regulations on the handling and disposal of the material (other than for transport which is federally regulated). Canadian Guidelines for the Management of Naturally Occurring Radioactive Materials have been developed by the Federal Provincial Territorial Radiation Protection Committee (FPtrPC)to harmonize standards throughout the country and ensure appropriate control over NORM. 27

28 IAEA Safety Standards/Reports Arcadis

29 ICRP Document Arcadis

30 Industrial Sources There are numerous types of sources Scrap metal contaminated with NORM or other rad wastes Industrial irradiation(c0-60, Cs-137) - Sterilization of medical and pharmaceutical products, food preservation, polymer synthesis Industrial radiography -non destructive testing (Cs-137, Co-60) Radioisotope production (I-131, cyclotron production of PE radionuclides for PET imaging) Well logging (rad sources gamma (Cs-137) and neutron (Am241Be source), or x-rays), sometimes sources are lost in wells Luminizing (e.g., gunsights, exit signs ) Space travel (RTGs, Po-210, Pu-238, ) Smoke detectors Arcadis

31 INDUSTRIAL (GAUGES) Fixed and portable Gauges may be transferred back to the supplier, to another licensee or to a waste disposal organization licensed by the CNSC. The inventory should be adjusted accordingly to reflect any transfers. Currently most sealed sources from gauges are transferred to CNL (formerly AECL) in Canada. Arcadis

32 Level Gauges Arcadis

33 Measuring Thickness Arcadis

34 Medical and Research Pharmaceutical Nuclear medicine Laboratory Accelerators Education Arcadis

35 Medical Waste Nuclear Medicine Commonly Used Isotopes in Nuclear Medicine are: I-123 I-131 Tc-99 m F-18 Y-90 microspheres(and many more) In Canada, all radioactive waste disposals must be managed and handled as per the CNSC s Nuclear Substances and Radiation Devices Regulations. Arcadis

36 LABORATORY WASTE Radioactive waste is segregated accordingly to halflives at most Universities and Research Facilities. Based on the isotope s half-life waste is segregated and the nuclear substance is usually stored in a licensed localized storage facility. Short-lived isotopes such Tc-99m, P-32, P-33, S-35 are delay decayed for 10 half-lives prior to disposal. If short-lived isotopes are to be disposed of in the normal waste stream their residual activity has to be measured and recorded by the institution prior to disposal usually done in consultation with the Radiation Safety Officer (RSO). Arcadis

37 LABORATORY WASTE Long-lived radionuclides are segregated by their half-life and are disposed of accordingly. Commonly used Long-lived radionuclides such as C-14 and H-3 are transferred to specialized licensed waste contractors. Arcadis

38 Accelerators Much of the radioactive waste material is bulky solid materials (especially metals) Unlike nuclear power wastes, rad wastes from accelerators Generally produce little alpha activity (except for special target materials) Less neutron rich radioactive species A large array of radionuclides The main waste streams are Operational - maintenance replacements, decontamination materials Decommissioning - residual operational wastes, structural concrete, shielding materials Arcadis

39 Concluding Remarks There are very many kinds of radioactive wastes arising from non-fuel cycle activities These wastes have a wide variety of radiological, chemical and physical forms Waste management requirements can lead to costly solutions In Canada there are few options for commercial disposal of radioactive wastes that cannot be managed by storage and decay Arcadis

40 Thank you! Arcadis 2017

41 Questions/Discussion Arcadis 2017