atw - International Journal for Nuclear Power | 2.2024

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54 Environment and Safety In 2015, NuScale Power developed a method for establishing the technical basis for plume exposure EPZ at NuScale SMR facilities and drafted a Licensing Topic Report (LTR), however this method therein described in this LTR is redacted in the filed version. The LTR presents the design-specific EPZ sizing method for the NuScale SMR, and this method is based on the NEI risk- informed EPZ method and extends it to address the issue of assessing the appropriate accident sequences to be considered [61] . A safety evaluation of this report was performed later in 2022 by the USNRC and subsequently, the LTR was approved by the USNRC [62] . The criteria for determining the EPZ for SMRs is typically defined by regulatory authorities and considers various factors to ensure the safety and protection of the public in the event of an emergency. Some of the criteria and corresponding approaches that are commonly considered for determining the EPZ for SMRs are shown in the following Table 9 [63] . Several researchers have also worked on EPZ methodology for SMRs, and their work is summarized in the following Table 10 and 11. Criteria Safety Analysis System analysis Accident Analysis Atmospheric Dispersion Models Atmospheric conditions Dose figure of merit Approach Deterministic or Probabilistic Reference SMR consideration Worst case scenario Diffusion of Plume Site specific, plant specific conditions plus atmospheric stability classes Total Effective Dose Equivalent (TEDE) Tab. 9. Guiding criteria for EPZ determination methods [63] Author (s) and Title Year Code Reactor type Methodology Main area of focus K. Kim et al, A study for establishment of Korean SMR EPZ Based on US SMR Approach [64], [65] 2021 MACCS2 SMART NEI EPZ setup methodology. PSA of source term categories J.C. de la Rosa Blul, Determination of Emergency Planning Zone Distances and scaling based criteria for downsized nuclear power plants [63] 2021 N/A iPWR SMR Scaling based criteria Use of plant specific data for dose consequence calculation Inverse method of extrapolating EPZ distances of reference, large NPP down to the SMR Plume pathway and it focused on accident analysis and PSA Comparison of radioactive releases from a large reactor and a small modular reactor T.S. Carless et al, Risk and regulatory con siderations for small modular reactor emergency planning zones based on passive decontamination potential [66] 2018 RASCAL Monte Carlo simulations iPWR Surry AP1000 Radionuclide Inventory and Plant specifications Decontamination factors in containment Atmospheric dispersion This study focused on comparison of radioactive release from different reactor types and their overall impact to the environment U.S. NRC Performance-based emergency preparedness for SMRs, Non-Light-Water Reactors, and Non-Power Production or utilization facilities [67] 2020 N/A SMR Non LWR D.W. Hummel et al. Radiation dose consequences of postulated limiting accidents in small modular reactors to inform emergency planning zone size requirements [68] 2019 ADDAM code HTGR MSR LFR iPWR Regulatory guide Radiation dose consequences Identifies methods and procedures the staff of the USNRC considers acceptable for SMR to demonstrate compliance with performance-based emergency preparedness requirements. Radiation dose conse quences arising from limiting accidents of various types of SMRs and study the dispersion of radionuclides to the atmosphere H. Ding et al. Development of Emergency Planning zone for high temperature gas-cooled reactor [55] 2017 MACCS- MELCOR Accident Consequence Code System HTR-PM Based on NUREG-0396 RG1.145 The principles that should be applied during EPZ development are deter mined by considering regulations and practice. the methodology follows NUREG-0396 Ausgabe 2 › März
Environment and Safety 55 Author (s) and Title Year Code Reactor type Methodology Main area of focus D. Mitrakos Radiological impact and emergency zones for small iPWR with different approaches for source term estimation [69] 2022 Solution of the lumped aerosol concentration equation in the containment iPWR Source term estimation Atmospheric dispersion model The first approach is based on US NRC, 2000. The second and third approaches are loosely considered as hybrid options in the sense of the suggestions in NEI (2012) Y. Lee, C. Kang, J.Moon. Reduction of EPZ Area for APR1400 and its public acceptance” [70] 2004 N/A APR1400 Based on NUREG 0396 The study performed a public poll to assess the degree of public acceptance to a reduction in the EPZ area and to identify the means of implementing the simplification of EPZ that would be most acceptable to the public. SMR Emergency Planning Zone Detection [80], [81], [82], [83], [84], [85] ting the proper size of the Emergency Planning Tab. 10. Literature review summary Approaches Probabilistic Safety Analysis (PSA) Accident Analysis/ Used Simulation Software Monte Carlo N-particle Simulation ASTEC code, Geiger Muller density, dispersion models, radiation dose limits, meteorological conditions, possible hazard releases, and other relevant factors are frequently considered while applying this method for EPZ determination [74], [75], [76] . System Code Counter, RASCAL Atmospheric PC Cosyma, HYSPLIT 5.2 Probabilistic Approaches Dispersion Analysis dispersion code, GIS software Various possible accident scenarios and their corresponding Tab. 11. probability are considered while estima Zone (EPZ) in the context of nuclear reactors using probabilistic approaches. Factors including population density, release characteristics, accident probability, and possible radiation exposure effects are included in these techniques [74] . Decommissioning nuclear facilities also necessitates the creation of emergency planning zones. When a nuclear facility is being decommissioned, the EPZ criterion states that the dosage value in the vicinity of the plant and the EPZ boundary must be less than 10 mSv, even with extremely cautious release methods and pathways [71] . Additionally, research reactors also require a defined Emergency Planning Zone size. In 2020, M. Hussain and his co-authors [72] did a research study to determine the Emergency Planning Zone for a nuclear research reactor using the plume code dispersion code for hypothetical accident scenarios at a 10 MW nuclear research reactor. The authors considered different accident scenarios with different release characteristics and environmental conditions to study the effect of the parameters including release height, heat content, release time, atmospheric stability. W. Xuan and co-authors also conducted a study to determine the EPZ for the Chinese CAP200 SMR where they analyzed the classification method of SMR EPZ based on the traditional Nuclear Power Plants feedback experience, including selection of source term, accident cutoff probability, determination method of the plume EPZ and the ingestion EPZ [73] . 5.1 Deterministic Approaches The deterministic method of estimating the size of an Emergency Planning Zone (EPZ) operates by applying predetermined standards and formulas. Population 5.3 Source Term Estimation and Atmospheric Dispersion models Source term estimation and atmospheric dispersion modeling techniques are frequently used to evaluate the possible release of hazardous substances and their dispersion in the atmosphere while establishing the radius of an Emergency Planning Zone (EPZ) for a nuclear facility. These techniques are crucial for determining the proper size of the EPZ and aid in estimating the possible impact‘s extent. It is also important to note the relevance of Atmospheric dispersion models because they simulate the spread and dilution of released radioactive materials in the atmosphere [76], [77], [78] . 5.4 Consequence Assessment Consequence assessment methods are techniques that evaluate the potential radiological impacts of a nuclear accident on the public and the environment. They involve the use of computer codes that simulate the physical processes of the accident, such as the release of radioactive material, the transport and dispersion of the plume, and the exposure pathways for the Vol. 69 (2024)
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ISSN: 1431-5254 (Print) | eISSN: 29
Page 4 and 5: 4 Contents Inhalt Editorial Abschie
Page 6 and 7: 6 Calendar Kalender 2024 07.03.2024
Page 8 and 9: 8 Feature: Energy Policy, Economy
Page 18 and 19: 18 Energy Policy, Economy and Law
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Page 52 and 53: 52 Environment and Safety Emergenc
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Page 58 and 59: 58 Environment and Safety [38] A.
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Page 68 and 69: 68 Research and Innovation replace
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Page 74 and 75: 74 Research and Innovation [12] Po
Page 76 and 77: 76 Spotlight on Nuclear Law auf Ko
Page 78 and 79: 78 KTG-Fachinfo KTG-Fachinfo 02/202
Page 80 and 81: 80 KTG-Fachinfo Regierungsbericht v
Page 82 and 83: 82 Vor 66 Jahren Ausgabe 2 › Mä
Page 88 and 89: 88 Kerntechnik 2024 Technical Sess
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atw - International Journal for Nuclear Power | 2.2024

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