scholarly journals Individual Effective Dose and Nuclear Emergency Planning for Muntok NPP Area using TMI-2 Source Term

2020 ◽  
Vol 22 (2) ◽  
pp. 65
Author(s):  
Sunarko Sunarko ◽  
Zaki Su'ud
Keyword(s):  
Nuclear Power ◽  
Source Term ◽  
Meteorological Data ◽  
Ground Level ◽  
Particle Dispersion ◽  
Air Concentration ◽  
Release Point ◽  
Loss Of Coolant Accident ◽  
Accident Data ◽  
Dry Conditions

Probabilistic dose analysis from a postulated nuclear accident is performed for the Muntok area in the western Bangka region. Three-Mile Island unit 2PWR-type Nuclear Power Plant (TMI-2) source-term is compiled and used as accident data. The accident is also known as the Small-break Loss of Coolant Accident (SB-LOCA) accident. The isotopes used in the simulation are Kr-88, I-131, Xe-133, and Cs-137. The release point is a 50 m stack. Lagrangian particle dispersion method (LPDM) is used along with a 3-dimensional mass-consistent wind-field. Surface-level time-integrated air concentration and spatial distribution of ground-level total dose were obtained for dry conditions. Meteorological data is taken from hourly records obtained from an on-site meteorological tower in Muntok area for the 2014-2015 period. Effluent is released at a uniform rate during a 6-hour period and the dose is integrated for 12 hours from the beginning of the release until most of the plume left the model boundaries. The regulatory limit for the general public of 1 mSv was detected in an area located 2.5 km from the release point. Radioactive plume is spread from the postulated plant location to uninhabited areas consisted of bushes and farming areas in the SE-SSE direction and to W-NW direction to the Bangka Sea.

scholarly journals Probabilistic Dose Assessment from SB-LOCA Accident in Ujung Lemahabang Using TMI-2 Source Term

2017 ◽  
Vol 2017 ◽  
pp. 1-8
Author(s):  
Sunarko ◽  
Zaki Su’ud ◽  
Idam Arif ◽  
Syeilendra Pramuditya
Keyword(s):  
Source Term ◽  
Meteorological Data ◽  
Atmospheric Condition ◽  
Ground Level ◽  
Particle Dispersion ◽  
Dose Assessment ◽  
Air Concentration ◽  
Reactor Accident ◽  
3 Dimensional ◽  
Java Sea

Probabilistic dose assessment and mapping for nuclear accident condition are performed for Ujung Lemahabang site in Muria Peninsula region in Indonesia. Source term is obtained from Three-Mile Island unit 2 (TMI-2) PWR-type SB-LOCA reactor accident inverse modeling. Effluent consisted of Xe-133, Kr-88, I-131, and Cs-137 released from a 50 m stack. Lagrangian Particle Dispersion Method (LPDM) and 3-dimensional mass-consistent wind field are employed to obtain surface-level time-integrated air concentration and spatial distribution of ground-level total dose in dry condition. Site-specific meteorological data is obtained from hourly records obtained during the Site Feasibility Study period in Ujung Lemahabang. Effluent is released from a height of 50 meters in uniform rate during a 6-hour period and the dose is integrated during this period in a neutrally stable atmospheric condition. Maximum dose noted is below regulatory limit of 1 mSv and radioactive plume is spread mostly to the W-SW inland and to N-NE from the proposed plant to Java Sea. This paper has demonstrated for the first time a probabilistic analysis method for assessing possible spatial dose distribution, a hypothetical release, and a set of meteorological data for Ujung Lemahabang region.

Assessment of Control Room Radiological Habitability of High-Temperature Reactor Pebble-Bed Module in Shidao Bay Multi-Reactor Nuclear Power Site

2018 ◽  
Author(s):  
Xinpeng Li ◽  
Sheng Fang
Keyword(s):  
High Temperature ◽  
Nuclear Power ◽  
Source Term ◽  
Meteorological Data ◽  
Dose Calculation ◽  
Dose Assessment ◽  
Specific Information ◽  
Control Room ◽  
Pebble Bed ◽  
High Temperature Reactor

The control room radiological habitability (CRRH) is important for staff safety in a nuclear power plant, which is also a licensing requirement of the High-temperature Reactor Pebble-bed Module (HTR-PM) in China. Meanwhile, the complexity of the dose assessment increases for the multi-reactor site, which put forward higher requirements for building layout. The CRRH is investigated comprehensively for the multi-reactor site at Shidao Bay in this study. For a large-break loss of coolant accident of HTR-PM and CAP1000 in Shidao Bay nuclear power site, this study estimates doses of body, thyroid and skin due to three exposure pathways using NRC-recommended ARCON96 and dose calculation method in RG 1.195. To perform a realistic evaluation, the latest design and site-specific information are utilized as the input parameters, including the unique accidental source term of HTR-PM and the RG1.183-recommended source term of CAP1000, the release and ventilation parameters, the final layout and the meteorological data in a whole year. The evaluation results demonstrate that the individual dose level of staff in the control room is far below the requirement of the regulatory guide, which guarantees the CRRH of HTR-PM. The contribution of primary radionuclides suggests that tellurium and iodine are primary contributors of the inhalation dose of body and thyroid, which is worthy of paying particular attention to the CRRH design in HTR-PM.

Operational evaluation of volcanic source terms (volcanic ash and SO2) from inverse modelling for aviation

2020 ◽  
Author(s):  
Mariëlle Mulder ◽  
Delia Arnold ◽  
Christian Maurer ◽  
Marcus Hirtl
Keyword(s):  
Source Term ◽  
Dispersion Model ◽  
Meteorological Data ◽  
A Priori ◽  
Radar Data ◽  
Particle Dispersion ◽  
Volcanic Emissions ◽  
Volcanic Source ◽  
Computational Resources ◽  
Different Sources

<p>An operational framework is developed to provide timely and frequent source term updates for volcanic emissions (ash and SO<sub>2</sub>). The procedure includes running the Lagrangian particle dispersion model FLEXPART with an initial (a priori) source term, and combining the output with observations (from satellite, ground-based, etc. sources) to obtain an a posteriori source term. This work was part of the EUNADICS-AV (eunadics-av.eu), which is a continuation of the work developed in the VAST project (vast.nilu.no). The aim is to ensuring that at certain time intervals when new observational and meteorological data is available during an event, an updated source term is provided to analysis and forecasting groups. The system is tested with the Grimsvötn eruption of 2011. Based on a source term sensitivity test, one can find the optimum between a sufficiently detailed source term and computational resources. Because satellite and radar data from different sources is available at different times, the source term is generated with the data that is available the earliest after the eruption started and data that is available later is used for evaluation.</p>

scholarly journals Detailed source term estimation of the atmospheric release for the Fukushima Daiichi Nuclear Power Station accident by coupling simulations of an atmospheric dispersion model with an improved deposition scheme and oceanic dispersion model

2015 ◽  
Vol 15 (2) ◽  
pp. 1029-1070 ◽  
Author(s):  
G. Katata ◽  
M. Chino ◽  
T. Kobayashi ◽  
H. Terada ◽  
M. Ota ◽  
...  
Keyword(s):  
Dose Rate ◽  
Nuclear Power ◽  
Source Term ◽  
Dispersion Model ◽  
Atmospheric Dispersion ◽  
Air Concentration ◽  
Power Station ◽  
Release Rates ◽  
Surface Deposition ◽  
Fukushima Daiichi

Abstract. Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident and their atmospheric and marine dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. In this paper, we estimate the detailed atmospheric releases during the accident using a reverse estimation method which calculates the release rates of radionuclides by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric and oceanic transport, dispersion and deposition models. The atmospheric and oceanic models used are WSPEEDI-II (Worldwide version of System for Prediction of Environmental Emergency Dose Information) and SEA-GEARN-FDM (Finite difference oceanic dispersion model), both developed by the authors. A sophisticated deposition scheme, which deals with dry and fog-water depositions, cloud condensation nuclei (CCN) activation, and subsequent wet scavenging due to mixed-phase cloud microphysics (in-cloud scavenging) for radioactive iodine gas (I2 and CH3I) and other particles (CsI, Cs, and Te), was incorporated into WSPEEDI-II to improve the surface deposition calculations. The results revealed that the major releases of radionuclides due to the FNPS1 accident occurred in the following periods during March 2011: the afternoon of 12 March due to the wet venting and hydrogen explosion at Unit 1, midnight of 14 March when the SRV (safety relief valve) was opened three times at Unit 2, the morning and night of 15 March, and the morning of 16 March. According to the simulation results, the highest radioactive contamination areas around FNPS1 were created from 15 to 16 March by complicated interactions among rainfall, plume movements, and the temporal variation of release rates. The simulation by WSPEEDI-II using the new source term reproduced the local and regional patterns of cumulative surface deposition of total 131I and 137Cs and air dose rate obtained by airborne surveys. The new source term was also tested using three atmospheric dispersion models (Modèle Lagrangien de Dispersion de Particules d'ordre zéro: MLDP0, Hybrid Single Particle Lagrangian Integrated Trajectory Model: HYSPLIT, and Met Office's Numerical Atmospheric-dispersion Modelling Environment: NAME) for regional and global calculations, and the calculated results showed good agreement with observed air concentration and surface deposition of 137Cs in eastern Japan.

scholarly journals Real-time use of inverse modeling techniques to assess the atmospheric accidental release from a nuclear power plant

2020 ◽  
Vol 55 (2) ◽  
pp. 107-115
Author(s):  
O. Saunier ◽  
I. Korsakissok ◽  
D. Didier ◽  
T. Doursout ◽  
A. Mathieu
Keyword(s):  
Inverse Modeling ◽  
Nuclear Power ◽  
Source Term ◽  
Atmospheric Dispersion ◽  
Air Concentration ◽  
Fukushima Accident ◽  
Modeling Tool ◽  
Modeling Techniques ◽  
Atmospheric Dispersion Models ◽  
Key Issues

The assessment of the source term including the time evolution of the release rate into the atmosphere and its distribution between radionuclides is one of the key issues in the understanding of the consequences of a nuclear accident. Inverse modeling methods, which combine environmental measurements, and atmospheric dispersion models have been proven to be efficient in assessing the source term due to an accidental situation. We developed our own tool, which has been applied to the Fukushima accident by using dose rate measurements and air concentration measurements. The inverse modeling tool has been implemented and tested during exercises implying fictitious radioactive releases with the aim of testing this method for emergency management. The exercises showed the relevance of the inverse modeling tool and it is a rewarding experience, which helped us to identify the required developments for the purpose of an operational use.

Study on Emergency Planning Zone Determination for CAP200 Small Modular Reactor

2018 ◽  
Author(s):  
Wang Xuan ◽  
Du Fenglei ◽  
Sun Dawei ◽  
Tang Te
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Source Term ◽  
Meteorological Data ◽  
Emergency Planning ◽  
Constraint Factor ◽  
Study Sites

Determination of the SMR emergency planning zone (EPZ) is one of the important external constraint factor of its marketing and application, which means that it is very important to formulate appropriate classification criteria and establish proper size range. In China, due to the requirement of “Criteria for emergency planning and preparedness for nuclear power plants: Part 1, The dividing of emergency planning zone.” (GB/T 17680.1-2008), for PWR nuclear power plant, its external plume EPZ should be within 7km–10km, and its internal plume EPZ should be within 3km∼5km. However, the scope of the standard for the emergency planning area is currently limited to conventional nuclear power plants, and for the current SMR, its emergency planning size is not included. In this paper, we will analyze 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. Three typical nuclear power plant sites in China are chosen as CAP200 case study sites, including two inland nuclear power plant sites and one coastal site. The three sites can represent most of the meteorological and terrain characters of China nuclear power plants. According to the CAP200 source term and meteorological data of the sites, MACCS2 computer program is used to calculate the severe accidents consequence. Conclusions show that for the CAP200 SMR, the accident cutoff probability can be 1.0E−08 to 1.0E−07 per reactor per year, and its project dose exceeding probability in the three sites boundary is far below 30%, which directs that for CAP200 SMR, its plume and ingestion emergence planning zone is limited to the on-site area, and its off-site emergency response can be simplified.

Evaluation of Iodine Source Term in PWR under Loss of Coolant Accident

2012 ◽  
Vol 482-484 ◽  
pp. 1115-1119 ◽  
Author(s):  
Khurram Mehboob ◽  
Xin Rong Cao
Keyword(s):  
Nuclear Power ◽  
Source Term ◽  
Fission Products ◽  
Retention Factor ◽  
Severe Accident ◽  
Loss Of Coolant Accident ◽  
Loss Of Coolant ◽  
Term Evaluation ◽  
Computer Based ◽  
Instantaneous Release

During the severe accident in nuclear power plant (NPP), large amounts of fission products are released with accident progression, including In-vessel and Ex-vessel release. Thus, the Source term evaluation is essential for the probability risk assessment (PRA) and is still imperative for the licensing and operation of NPPs. Iodine is one of the most reactive fission products emitting in a large amount to containment and have a severe impact on health and sounding environment. Therefore, the iodine source term has been evaluated for 1000MW Reactor, by considering the TMI-2 as the reference reactor. The modeling and simulation of released radioactivity have been carried out by developing a MATLAB computer-based program. For post 1100 operation days, with the instantaneous release of radioactivity to the containment has been studied under LOCA. The dependency of radioiodine on ventilation exhaust rates has been studied in normal, emergency and isolation mode of containment. Moreover, the containment retention factor is also evaluated in said states of containment.

Sign in / Sign up

Export Citation Format

Share Document