Spent nuclear fuel storage pool thermal hydraulic analysis pdf

All nuclear plants have storage pools for spent fuel. Spent nuclear fuel storage pool thermal hydraulic analysis. Chapter 7 thermalhydraulic analysis the coolant in the pressure tube of the candu nuclear reactor core removes the thermal energy produced in the nuclear fuel. Nuclear fuel is operated under very inhospitable conditions thermal, radiation, mechanical and must withstand more than normal conditions operation. The hydraulic diameter, d h, is a commonly used term when handling flow in noncircular tubes and channels. To assess the safety of the spent fuel storage pools, a low probability accident can be postulated in which all of the water drains from the pool, leaving the storage racks and their contents exposed to the air. Analysis of the processes in spent fuel pools in case of loss of. Reducing the hazards from stored spent powerreactor fuel in the. Summary of separate effect tests on high temperature air oxidation. Heat transfer modeling of dry spent nuclear fuel storage facilities full record.

Pdf the safe storage of spent fuel assemblies in the spent fuel pools is very important. The thermalhydraulic processes in the storage of spent nuclear fuel snf, which includes a pool of water for storing canisters with spent fuel assemblies sfa filled with water, for reliable and safe operation of such storage facilities were modeled and simulated. It is important to recognize that, without exception, the wet storage of spent nuclear fuel precedes dry storage in all watercooled reactors, and that the duration of wet storage i. Our design can effectively manage the sfp temperature not to exceed 80 c. Nuclear energy institutes everett redmond, director of nonproliferation and fuel cycle policy, describes the purpose and design of a spent fuel pool to safely store used fuel at nuclear energy. Storage pool thermal hydraulic analysis 209 the cells in the spent fuel storage pool medium are assumed to contain cylindrical fuel rods enclosed in a rectangular channel. These facilities are licensed separately from a nuclear power plant and are considered independent even though they may be located on the site of another nrclicensed facility. Thermalhydraulic design and transient analysis of passive air cooling system for cpr spent fuel storage pool li ge, junli gou, jianqiang shan, bin zhang, bo zhang, zijiang yang school of nuclear science and technology, xian jiaotong university, no.

Over the past several decades, the inventory of commercial spent nuclear fuel in storage in the. The spent fuel dry storage system of hightemperature reactor pebblebed modules in china is simulated using the tacds to confirm the design basis and to analyze the transient behavior following an accident involving blower failure. Thermalhydraulic analysis of nuclear reactors zohuri, bahman on. Schematic illustration of thermalhydraulic conditions expe cted in the pre uncovery. Pdf spent fuel discharged from nuclear reactors must necessarily be. Spent fuel is stored either in the atreactor pool or in awayfromreactor wet facilities, where the fuel elements are maintained until submission to final disposal, or until the decay heat is low enough to allow migration to a dry storage facility. Analysis of lofa in bwr spent fuel storage pool nuclear society. In addition, appropriate boundary and initial conditions are required. If probabilistic analysis is of little help for evaluating the risks of terrorism, the nrc. With a strong focus on system thermal hydraulics sys th, the book provides a detailed, yet approachable, presentation of current approaches to reactor thermal hydraulic analysis, also. Guidance is provided on all stages in the lifetime of a spent fuel storage facility, from planning through siting and design to operation and decommissioning, and in particular. Investigation of spent nuclear fuel pool coolability.

The spent fuel pool will be a wet facility, and the fuel assemblies stored therein will be kept submerged in borated water. In many countries, the fuel assemblies, after being in the reactor for 3 to 6 years, are. Thermalhydraulic design and transient analysis of passive. And nuclear supervision service scientific and engineering centre for nuclear and radiation safety. Appendix b proposed spent nuclear fuel storage act of 1979 b1. Guidance on spent fuel pool modifications, entitled nrc. There must be confidence in the continued integrity of the fuel, its container, and the structure of the waste store, for example. Thermal analyses of spent nuclear fuel repository tiivistelma.

Pdf safety analysis of spent fuel pool in case of loca. The thermal hydraulic processes in the storage of spent nuclear fuel snf, which includes a pool of water for storing canisters with spent fuel assemblies sfa filled with water, for reliable and safe operation of such storage facilities were modeled and simulated. Status report on spent fuel pools under lossofcooling and loss. Abstractwe report the development of a thermalhydraulic analysis code called tacds. Analysis of the processes in spent fuel pools in case of. The safety guide is not intended to cover the storage of spent fuel if this is part of the operation of a nuclear power plant or spent fuel reprocessing facility.

Interim storage of used or spent nuclear fuel february 2008 background for position statement 76 american nuclear society outreach program 708 3526611 federal affairs 708 3526611. Untr08001np, spent and new fuel storage analyses for. Introduction in a research project named sinabel security of wet storage facility for spent fuel new knowledges of the thermalhydraulic phenomena in the storage pool are to be acquired. Spent fuel storage pool and spent fuel cooling system.

This report summarizes preliminary thermal hydraulic scoping analysis and model development associated with the k basin spent fuel mco draining and vacuum drying system. The rate and form of energy transfer from the nuclear fuel through the cladding and to the coolant is strongly depend ent upon the local thermal and hydraulic conditions. Spent fuel storage is one of the important stages in the nuclear fuel cycle and stands among. Nuregcr6441, analysis of spent fuel heatup following loss of. Thermalhydraulic analysis code for drystorage system. Air, as with any gas, has too low density and a speci. For example temperatures in the centre of fuel pellets reach more than c. In the bottom 14 feet are storage racks designed to hold fuel assemblies removed from the reactor. Spent nuclear fuel is removed from the reactor and placed in the spent fuel pool for storage.

Thermalhydraulics of water cooled nuclear reactors 1st. The author does not deny the possibility of slightly prolonging the boiling with other designs. Article pdf available in science and technology of nuclear installations. The spent fuel drystorage system of hightemperature reactor pebblebed modules in china is simulated using the tacds to confirm the design basis and to analyze the transient behavior following an accident involving blower failure. Development of a thermalhydraulic analysis code tacds. Turkey point spent fuel storage cask pit rack pla analyses criticality criteria per 10 cfr 50. Nuregcr6441, analysis of spent fuel heatup following. Pdf analysis of the processes in spent fuel pools in case of loss. Then the transient analysis of the cpr sfp with designed passive cooling system is carried out in station blackout sbo accident by the bestestimate thermalhydraulic system code relap5. Organisation for economic cooperation and development. Plans for a geologic repository have gone unrealized, so many operating nuclear power plants have begun storing spent fuel at independent spent fuel storage installations at or near the plants. These facilities are licensed separately from a nuclear power plant and are considered independent even though they.

Using this term, one can calculate many things in the same way as for a round tube. An important safety issue is how to establish the safety of the facilities for longterm storage of spent fuel. Also, the accident mitigation measure, the late injection of water was evaluated. Technical study of spent fuel pool accident risk at. An independent spent fuel storage installation, or isfsi, is a facility that is designed and constructed for the interim storage of spent nuclear fuel. Virtually all power reactors have some form of spent fuel pools associated with. Following discharge from a nuclear reactor, spent fuel has to be stored in water pools at the reactor site.

It is no longer useful in sustaining a nuclear reaction in an ordinary thermal reactor and depending on its point along the nuclear fuel cycle, it may have considerably different isotopic constituents. System analysis and isothermal separate effect experiments. Mar 28, 2011 nuclear energy institutes everett redmond, director of nonproliferation and fuel cycle policy, describes the purpose and design of a spent fuel pool to safely store used fuel at nuclear energy. Isl supports domestic and international clients in nuclear reactor safety, security, regulatory and environmental assessment with a focus on thermalhydraulic analysis and probabilistic risk assessment. Assessment of thermal behavior of spent nuclear fuel. Abstract this report contains the temperature dimensioning of the kbs3v type 1 or 2panel repository based on the rock properties measured from the olkiluoto investigations. Storage of foreign spent power reactor fuel april 1980 u. Modeling the thermal and chemical response of spent fuel assemblies to the. Safety and security of commercial spent nuclear fuel storage. Computational fluid dynamics for nuclear power plants. This report documents a study of spent fuel pool sfp accident risk at decommissioning nuclear power plants. Abstractwe report the development of a thermal hydraulic analysis code called tacds. Spent nuclear fuel, occasionally called used nuclear fuel, is nuclear fuel that has been irradiated in a nuclear reactor usually at a nuclear power plant. Schematic illustration of thermal hydraulic conditions expe cted in the pre uncovery.

Dynamic impact force behavior of spent fuel pool using. Improved hydraulic manipulators are useful to handle radioactive material under water. Request pdf thermal hydraulics analysis on a simplified model of spent fuel pool the spent fuel still has massive decay heat and is temporarily stored in the spent fuel pool, after unloaded. This paper proposes a design of passive cooling system for cpr spent fuel pool sfp. Jan 03, 2020 division of systems safety and analysis office of nuclear reactor regulation u. Thermal analysis of stored casks thermal optimization studies of cask arrangements hvac analysis of spent fuel handling and storage facilities fire dynamics simulations tunnel fires other forms of pool fires use of nist fire dynamics simulator and other commercial codes computational fluid dynamics for spent fuel storage. Mathematical model of the processes was considered. This analysis was used to guide the development of global response models to examine the thermalhydraulic behavior of an entire spent fuel pool. Heat transfer modeling of dry spent nuclear fuel storage. Design characteristics of spent fuel pool used in the analysis. Spent fuel pool probabilistic risk assessment modeling. Used fuel assemblies removed from the reactor will be stored.

An introduction to the thermalhydraulic aspects of nuclear power reactors. Nuclear regulatory commission washington, dc 205550001. This study contains the results of the nrc staffs evaluation of the potential accident risk in a spent fuel pool at decommissioning plants in the united states. The phenomena, taking place during such accident, are discussed. Modeling of the thermal processes in repository of the. The analysis was performed for the ignalina npp unit 2 spent fuel pool, using system thermal hydraulic code for severe accident analysis athletcd. Thermal hydraulics analysis on a simplified model of spent. In section 2 the development of analytical methods for the thermalhydraulic analysis of spent fuel pools is chronicled, leading up to a discussion of the gflow. Summary of spent fuel pool chemistry, radiochemistry.

Storage pool thermal hydraulic analysis 225 the above sensitivity study indicates that con solidated fuel bundles with the same total heat generation rate per rack storage location would only have a few degrees fahrenheit increased exit tempera ture over normal fuel assemblies. Spent fuel is stored in water pool until its decay heat decreases. Heat transfer modeling of dry spent nuclear fuel storage facilities title. Safety and security of commercial spent nuclear fuel. Technical meeting on the phenomenology simulation and modelling of accidents in spent fuel pools 25 september 2019, ieae, vienna, austria assessment of thermal behavior of spent nuclear fuel storage pool in the exsiccation accident. Pdf the daya bay spent fuel pool was chosen as the analysis object and the best estimate system thermal hydraulic code relap5mod3. New technology plans for using a nuclear airbrayton as a storage system for a low carbon grid are presented along with updated component sizes and performance criteria for small. According to nuclear plant safety specialists, the chances of criticality in a spent fuel pool are very small, usually avoided by the dispersal of the fuel assemblies, inclusion of a neutron absorber in the storage racks and overall by the fact that the spent fuel has too low an enrichment level to selfsustain a. Good practices for water quality management in research. Thermal hydraulic analysis code for dry storage system. Thermal hydraulic design and transient analysis of passive air cooling system for cpr spent fuel storage pool li ge, junli gou, jianqiang shan, bin zhang, bo zhang, zijiang yang school of nuclear science and technology, xian jiaotong university, no. Computational fluid dynamics for spent fuel storage and. Thermal hydraulic fundamentals, second edition provides an indepth introduction to nuclear power, with a focus on thermal hydraulic design and analysis of the nuclear core.

Melcor to examine five configurations of fuel storage in spent fuel pools. The report describes first the development of a calculation methodology for the thermal analysis of a. Concrete casks that rely on conductive heat transfer have more thermal. Spent fuel pools are typically 40 or more feet deep.

Lower plenum flow analysis thermal analysis of spent fuel casks intermediate heat exchanger flow and thermal analysis detailed componentlevel modeling of reactor sections and parts numerical study of spent fuel storage facilities particulate flow analyses for nuclear applications. The purpose of the draining and drying system is to remove all free water from the interior of the mco, baskets, and fuel prior to back filling with inert gas and transfer to the hot conditioning process. Reducing the deadly risks of storage by robert alvarez the price of fixing americas nuclear vulnerabilities may be high, but the price of doing too little is incalculable. Fuel storage racks in the spent fuel pool exhibited sliding, rotation, and tip over phenomena due to seismic loads.

The spent nuclear fuel is stored either wet in pools of water or dry in storage systems that typically consist of stainless steel canisters within protective casks. Operation and maintenance of spent fuel storage and. Over the past several decades, the inventory of commercial spent nuclear fuel in storage in the united states has grown to about 72,000 metric tons. Thermal analysis of spent nuclear fuels repository author. Division of systems safety and analysis office of nuclear reactor regulation u. Isl supports domestic and international clients in nuclear reactor safety, security, regulatory and environmental assessment with a focus on thermal hydraulic analysis and probabilistic risk assessment. Spent fuel storage in pools at nuclear energy plants. The hydraulic diameter transforms noncircular ducts into pipes of equivalent diameter. It is assumed for purposes of analysis that this foreign fuel will eventually be disposed of as waste in a u. A methodology for predicting spent fuel heatup in the. Spent fuel pools contain enormous amounts of water and are strong structures constructed of very thick steel. A close examination of new developments in nuclear systems, this book will help readers. Written by leading experts from mit, nuclear systems volume i. Research article analysis of the processes in spent fuel.