Decommissioning, clearance levels and acceptance criteria requirements and standards

Transcription

1 Universität für Bodenkultur Wien Department für Wald- und Bodenwissenschaften Decommissioning, clearance levels and acceptance criteria requirements and standards Franz Josef Maringer Low-Level Counting Laboratory Arsenal, Vienna 1

2 Decommissioning - examples 1 Ignalina, Lithuania, 3rd unit, aerial view 2 Chapelcross, UK cooling towers blasting 3 Yankee, Connecticut, USA NURIS 2015 FJ Maringer: Decomissioning, clearance levels and acceptance criteria

3 Risc radiation protection Science (doses and risks) UNSCEAR Philosophy and Policy ICRP Regulatory Practicalities IAEA 3

4 ICRP International Basic Safety Standards

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6 Detriment ICRP 60(1990) ICRP 103 (2007) q T ( ) = qmin + kt 1 q min 6

7 ICRP 103(2007) 7

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9 Requirement 5: Responsibilities of the regulatory body for decommissioning Establishing requirements relating to the criteria for safety, protection of workers and the public, and protection of the environment during the decommissioning of facilities, including criteria for clearance of material from regulatory control in accordance with national policy; (2014) 9

10 Concepts of exclusion, exemption and clearance 10

11 Internat. Basic Safety Standards

12 Internat. Basic Safety Standards 2014 (2005) General dose criteria Definition of exposure scenarios & radioecological modelling Derived activity concentrations 12

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15 Development of standardised traceable measurement methods for solid radioactive waste free release (clearance levels verification) and for acceptance of solid radioactive wastes to repositories (acceptance criteria verification), according to international recommendations (EC and IAEA): as well as design of measurement facilities, software, calibration and testing methods. Development of novel instruments and methods for in-situ measurements: this includes improved on-site radiochemical analysis, rapid in-situ screening techniques for alpha, beta and gamma emitters and measurement of activity at varying depth. 15

16 Development of a gaseous effluent monitor/sampler for stored wastes. Rapid, sensitive methods are required to determine rates of bulk gas production, chemical composition (CH 4, CO 2 or H 2 ) and activity concentrations of key radionuclides (e.g. H-3, C-14, Rn-222). Development of standards and spiked or characterised real reference materials for ensuring accurate, traceable radio-assays of materials from sites (concrete, steel, aluminium, cables, wood, insulator and others). Improvements to decay data for selected radionuclides present in nuclear wastes, focusing on half-life measurements of long-lived fission and activation products. 16

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20 Applied Radiation and Isotopes 81 (2013)

21 Nuclear decommissioning Shutdown reactors and facilities (August 2013): power reactors: 89 EU, 143 worldwide research reactors: 46 EU, 142 worldwide fuel facilities: 31 EU, 96 worldwide Operating reactors and facilities (August 2013): power reactors: 137 EU, 437 worldwide research reactors: 61 EU, 246 worldwide fuel facilities: 76 EU, 332 worldwide More than one third of the 137 reactors currently operating in the EU will need to be shut down by GlobalData s report shows that the European commercial nuclear decommissioning market value stands at more than 60,000 million EUR. 21

22 Conclusions Actions need in Expertise in sustainable decommissioning Risk assessment in decommissioning Reliable / traceable measurement methods Appropriate exposure scenarios International / European harmonization of standards Science practice experience improvement 22