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Natural circulation data and methods for advanced water cooled nuclear power plant designs. Proceedings of a technical committee meeting

Abstract

The complex set of physical phenomena that occur in a gravity environment when a geometrically distinct heat sink and heat source are connected by a fluid flow path can be identified as natural circulation (NC). No external sources of mechanical energy for the fluid motion are involved when NC is established. Within the present context, natural convection is used to identify the phenomena that occur when a heat source is put in contact with a fluid. Therefore, natural convection characterizes a heat transfer regime that constitutes a subset of NC phenomena. This report provides the presented papers and summarizes the discussions at an IAEA Technical Committee Meeting (TCM) on Natural Circulation Data and Methods for innovative Nuclear Power Plant Design. While the planned scope of the TCM involved all types of reactor designs (light water reactors, heavy water reactors, gas-cooled reactors and liquid metal-cooled reactors), the meeting participants and papers addressed only light water reactors (LWRs) and heavy water reactors (HWRs). Furthermore, the papers and discussion addressed both evolutionary and innovative water cooled reactors, as defined by the IAEA. The accomplishment of the objectives of achieving a high safety level and reducing the cost through the reliance on NC mechanisms,  More>>
Authors:
"NONE"
Publication Date:
Apr 01, 2002
Product Type:
Technical Report
Report Number:
IAEA-TECDOC-1281
Resource Relation:
Conference: Technical committee meeting on natural circulation data and methods for advanced water cooled nuclear power plant designs, Vienna (Austria), 18-21 Jul 2000; Other Information: Refs, figs, tabs; PBD: Apr 2002
Subject:
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; ECONOMICS; FLUID FLOW; HEAT TRANSFER; HEAVY WATER COOLED REACTORS; LEADING ABSTRACT; NATURAL CONVECTION; REACTOR COOLING SYSTEMS; REACTOR SAFETY; WATER COOLED REACTORS; MEETINGS
OSTI ID:
20246455
Research Organizations:
International Atomic Energy Agency, Vienna (Austria)
Country of Origin:
IAEA
Language:
English
Other Identifying Numbers:
TRN: XA0201507018369
Availability:
Available from INIS in electronic form
Submitting Site:
INIS
Size:
252 pages
Announcement Date:

Citation Formats

Natural circulation data and methods for advanced water cooled nuclear power plant designs. Proceedings of a technical committee meeting. IAEA: N. p., 2002. Web.
Natural circulation data and methods for advanced water cooled nuclear power plant designs. Proceedings of a technical committee meeting. IAEA.
2002. "Natural circulation data and methods for advanced water cooled nuclear power plant designs. Proceedings of a technical committee meeting." IAEA.
@misc{etde_20246455,
title = {Natural circulation data and methods for advanced water cooled nuclear power plant designs. Proceedings of a technical committee meeting}
abstractNote = {The complex set of physical phenomena that occur in a gravity environment when a geometrically distinct heat sink and heat source are connected by a fluid flow path can be identified as natural circulation (NC). No external sources of mechanical energy for the fluid motion are involved when NC is established. Within the present context, natural convection is used to identify the phenomena that occur when a heat source is put in contact with a fluid. Therefore, natural convection characterizes a heat transfer regime that constitutes a subset of NC phenomena. This report provides the presented papers and summarizes the discussions at an IAEA Technical Committee Meeting (TCM) on Natural Circulation Data and Methods for innovative Nuclear Power Plant Design. While the planned scope of the TCM involved all types of reactor designs (light water reactors, heavy water reactors, gas-cooled reactors and liquid metal-cooled reactors), the meeting participants and papers addressed only light water reactors (LWRs) and heavy water reactors (HWRs). Furthermore, the papers and discussion addressed both evolutionary and innovative water cooled reactors, as defined by the IAEA. The accomplishment of the objectives of achieving a high safety level and reducing the cost through the reliance on NC mechanisms, requires a thorough understanding of those mechanisms. Natural circulation systems are usually characterized by smaller driving forces with respect to the systems that use an external source of energy for the fluid motion. For instance, pressure drops caused by vertical bends and siphons in a given piping system, or heat losses to environment are a secondary design consideration when a pump is installed and drives the flow. On the contrary, a significant influence upon the overall system performance may be expected due to the same pressure drops and thermal power release to the environment when natural circulation produces the coolant flow. Therefore, the level of knowledge for the thermal-hydraulic phenomena for the specific geometric conditions and governing heat transfer conditions should be deeper when NC is involved. In addition, the lower driving forces for natural circulation systems might lead to quite large equipment for which the role of 3D phenomena is essentially increased. Within nuclear technology the renewed interest in NC is a consequence of the above, in combination with the potential for cost savings from increased use of NC mechanisms in plant designs. Relevant experiments directed to the characterization of NC have been carried out in the past because of the importance of the related mechanisms for the safety of existing reactors. Similarly, thermal-hydraulic system codes have been qualified through the comparison of predicted results and experimental data. The quality of recorded experimental data and the precision level of the available system codes, or the expected uncertainty in these predictions, are generally evaluated as satisfactory for the needs of the current reactors. However, the exigencies posed by the more extensive use of the NC in the design of evolutionary and innovative water cooled reactors require a re-evaluation of the experimental data and of the code capabilities considering the new phenomena and conditions involved. This report provides an overview of the current state of the art of natural circulation data and methods, and discusses potential benefits of an integrated future effort directed toward the achievement of the two aforementioned objectives. The main attention in this report is paid to the design basis accident phenomena; severe accident issues are considered briefly in their relation to the protection of the containment as the last safety barrier.}
place = {IAEA}
year = {2002}
month = {Apr}
}