New Approach for Environmental Protection During Severe Accidents at Nuclear Power Plants

2009 ◽  
Author(s):  
S. A. Kulyukhin ◽  
N. B. Mikheev ◽  
L. N. Falkovskii ◽  
L. A. Reshetov ◽  
M. Ya. Zvetkova ◽  
...  
Keyword(s):  
Environmental Protection ◽  
Nuclear Power ◽  
Power Plants ◽  
Heat Removal ◽  
Passive Mode ◽  
Pressure Release ◽  
Spray System ◽  
Severe Accidents ◽  
Heat Removal System ◽  
New Generation

This paper reports new approaches for increasing environmental protection during severe accidents at NPPs. For NPPs with two protective shells and pressure release system such as WWER-1000 we suggest a new comprehensive, passive-mode environmental protection system of decontamination of the radioactive air-steam mixture from the containment and the intercontainment area, which includes the “wet” stage (scrubbers, etc.), the “dry” stage (sorption module), and also an ejector, which in a passive mode is capable of solving the multi-purpose task of decontamination of the air-steam mixture. For Russian WWER-440/V-230 NPPs we suggest three protection levels: 1) a jet-vortex condenser; 2) the spray system; 3) a sorption module. For modern designs of new generation NPPs, which do not provide for pressure release systems, we proposed a new passive filtering system together with the passive heat-removal system, which can be used during severe accidents in case all power supply units become unavailable.

Setup of the Supercritical CO2 Test Facility “SCARLETT” for Basic Experimental Investigations of a Compact Heat Exchanger for an Innovative Decay Heat Removal System

2018 ◽  
Vol 4 (3) ◽  
Author(s):  
Wolfgang Flaig ◽  
Rainer Mertz ◽  
Joerg Starflinger
Keyword(s):  
Heat Exchanger ◽  
Supercritical Co2 ◽  
Nuclear Power ◽  
Power Plants ◽  
Heat Removal ◽  
Test Facility ◽  
Experimental Investigations ◽  
Decay Heat ◽  
Heat Removal System ◽  
Removal System

Supercritical fluids show great potential as future coolants for nuclear reactors, thermal power, and solar power plants. Compared to the subcritical condition, supercritical fluids show advantages in heat transfer due to thermodynamic properties near the critical point. A specific field of interest is an innovative decay heat removal system for nuclear power plants, which is based on a turbine-compressor system with supercritical CO2 as the working fluid. In case of a severe accident, this system converts the decay heat into excess electricity and low-temperature waste heat, which can be emitted to the ambient air. To guarantee the retrofitting of this decay heat removal system into existing nuclear power plants, the heat exchanger (HE) needs to be as compact and efficient as possible. Therefore, a diffusion-bonded plate heat exchanger (DBHE) with mini channels was developed and manufactured. This DBHE was tested to gain data of the transferable heat power and the pressure loss. A multipurpose facility has been built at Institut für Kernenergetik und Energiesysteme (IKE) for various experimental investigations on supercritical CO2, which is in operation now. It consists of a closed loop where the CO2 is compressed to supercritical state and delivered to a test section in which the experiments are run. The test facility is designed to carry out experimental investigations with CO2 mass flows up to 0.111 kg/s, pressures up to 12 MPa, and temperatures up to 150 °C. This paper describes the development and setup of the facility as well as the first experimental investigation.

scholarly journals Urgent Problems in Thermal Physics of Design-Basis and Severe Accidents at Nuclear Power Plants

2016 ◽  
pp. 32-36
Author(s):  
I. Sharaievskii ◽  
N. Fialko ◽  
A. Nosovsky ◽  
L. Zimin ◽  
G. Sharaievskii
Keyword(s):  
Nuclear Fuel ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Heat Removal ◽  
Thermal Physics ◽  
Severe Accidents ◽  
Design Basis

The paper considers thermal and physical aspects in dynamics of design-basis and severe accidents at water-cooled nuclear power reactors with nuclear fuel damage. The most promising concepts of the corium confinement in the damaged reactor were analyzed. The main objective was to define the main areas to search and implement methods of efficient and safe heat removal in progression of emergencies.

Kinetic Study of Containment Retention Factor (CRF) for Large Dry Containment Under Radiation Load

2014 ◽  
Author(s):  
Khurram Mehboob ◽  
Kwangheon Park ◽  
Rehan Khan ◽  
Majid Ali ◽  
Raheel Ahmed
Keyword(s):  
Kinetic Study ◽  
Nuclear Power ◽  
Power Plants ◽  
Heat Removal ◽  
Fission Products ◽  
Retention Factor ◽  
Severe Accident ◽  
Spray System ◽  
Filtration System ◽  
Kinetic Dependency

The Nuclear Power Plants (NPPs) have been built on the concept of Defense in depth. The severe accident causes the failure of fission product barriers and let the fission products to escape into environment. The containment is the last barrier to the fission products. Thus, the containment is installed with engineering safety features (ESFs) i.e. spray system, heat removal system, recirculation filtration system; containment filtered venting system (CFVS), and containment exhaust filtration system. In this work, kinetic study of the containment retention factor (CRF) has been carried out for a large dry PWR containment considering 1000 MWe PWR. The computational modeling and simulation have been carried out by developing a kinetic code in MATLAB, which uses the fractions of activity airborne into the containment after the accident. The Kinetic dependency of CRF on containment filtration systems, spray system with caustic and boric acid spray has been carried out. For noble gases, iodine and aerosols, the CRF increases with the increase in exhaust rate. While, CRF for iodine first increases then start reducing with containment spray flow rate. The Kinetic dependency of CRF has also been studied for boric and caustic spray.

The New Generation of High-Pressure Heaters for Steam Turbine Units at Nuclear Power Plants

2021 ◽  
Vol 68 (4) ◽  
pp. 285-294
Author(s):  
V. M. Zorin ◽  
A. S. Shamarokov ◽  
S. B. Pustovalov
Keyword(s):  
High Pressure ◽  
Steam Turbine ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
New Generation

scholarly journals Seismic safety evaluation during site selection for the nuclear power plants in Bangladesh

2018 ◽  
Vol 4 (4) ◽  
pp. 251-256 ◽  
Author(s):  
Sergey Shcheklein ◽  
Ismail Hossain ◽  
Mohammad Akbar ◽  
Vladimir Velkin
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Spent Nuclear Fuel ◽  
Heat Removal ◽  
Good Time ◽  
Diagnostics System ◽  
Seismic Impacts

Bangladesh lies in a tectonically active zone. Earlier geological studies show that Bangladesh and its adjoining areas are exposed to a threat of severe earthquakes. Earthquakes may have disastrous consequences for a densely populated country. This dictates the need for a detailed analysis of the situation prior to the construction of nuclear power plant as required by the IAEA standards. This study reveals the correlation between seismic acceleration and potential damage. Procedures are presented for investigating the seismic hazard within the future NPP construction area. It has been shown that the obtained values of the earthquake’s peak ground acceleration are at the level below the design basis earthquake (DBE) level and will not lead to nuclear power plant malfunctions. For the most severe among the recorded and closely located earthquake centers (Madhupur) the intensity of seismic impacts on the nuclear power plant site does not exceed eight points on the MSK-64 scale. The existing predictions as to the possibility of a super-earthquake with magnitude in excess of nine points on the Richter scale to take place on the territory of the country indicate the necessity to develop an additional efficient seismic diagnostics system and to switch nuclear power plants in good time to passive heat removal mode as stipulated by the WWER 3+ design. A conclusion is made that accounting for the predicted seismic impacts in excess of the historically recorded levels should be achieved by the establishment of an additional efficient seismic diagnostics system and by timely switching the nuclear power plants to passive heat removal mode with reliable isolation of the reactor core and spent nuclear fuel pools.

scholarly journals Simulation of Steady States of Helium Loop at Long Time Scenarios

2020 ◽  
Vol 328 ◽  
pp. 01009
Author(s):  
František Világi ◽  
Branislav Knížat ◽  
Róbert Olšiak ◽  
Marek Mlkvik ◽  
Peter Mlynár ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Natural Circulation ◽  
Heat Removal ◽  
Iteration Process ◽  
Heat Accumulation ◽  
Proposed Model ◽  
Long Time ◽  
Convection Cooling

The natural circulation helium loop is an experimental facility designed for the research of the possibility of utilizing natural convection cooling for the case of decay heat removal from a fast nuclear reactor. This concept would bring an improved automated safety system for future nuclear power plants operating a gas-cooled reactor. The article presents a new possibility of direct use of energy conservation laws in a 1D simulation of natural circulation loops. The calculation is performed by a triple iteration process, nested into each other. The results of the calculations showed good agreement with the measurements at steady state. A calculation with the proposed model at unsteady state is not yet possible, especially because of the exclusion of heat accumulation into the material.

scholarly journals Spreading of Excellence in SARNET Network on Severe Accidents: The Education and Training Programme

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Sandro Paci ◽  
Jean-Pierre Van Dorsselaere
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Training Programme ◽  
Education And Training ◽  
Severe Accident ◽  
Research Network ◽  
Safety Issues ◽  
Severe Accidents ◽  
Management Procedures ◽  
And Training

The SARNET2 (severe accidents Research NETwork of Excellence) project started in April 2009 for 4 years in the 7th Framework Programme (FP7) of the European Commission (EC), following a similar first project in FP6. Forty-seven organisations from 24 countries network their capacities of research in the severe accident (SA) field inside SARNET to resolve the most important remaining uncertainties and safety issues on SA in water-cooled nuclear power plants (NPPs). The network includes a large majority of the European actors involved in SA research plus a few non-European relevant ones. The “Education and Training” programme in SARNET is a series of actions foreseen in this network for the “spreading of excellence.” It is focused on raising the competence level of Master and Ph.D. students and young researchers engaged in SA research and on organizing information/training courses for NPP staff or regulatory authorities (but also for researchers) interested in SA management procedures.

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