Nuclear Energy Research Initiative Research Articles

The Neutronics Design and Analysis of a 200-MW(electric) Simplified Boiling Water Reactor Core

A 200-MW(electric) simplified boiling water reactor (SBWR) was designed and analyzed under sponsorship of the U.S. Department of Energy Nuclear Energy Research Initiative program. The compact size of a 200-MW(electric) reactor makes it attractive for countries with a less well developed engineering infrastructure, as well as for developed countries seeking to tailor generation capacity more closely to the growth of their electricity demand. The 200-MW(electric) core design reported here is based on the 600-MW(electric) General Electric SBWR core, which was first analyzed in the work performed here in order to qualify the computer codes used in the analysis. Cross sections for the 8 × 8 fuel assembly design were generated with the HELIOS lattice physics code, and core simulation was performed with the U.S. Nuclear Regulatory Commission codes RELAP5/PARCS. In order to predict the critical heat flux, the Hench-Gillis correlation was implemented in the RELAP5 code. An equilibrium cycle was designed for the 200-MW(electric) core, which provided a cycle length of more than 2 yr and satisfied the minimum critical power ratio throughout the core life.

ICONE11-36542 LATE-PHASE MELT CONDITIONS AFFECTING THE POTENTIAL FOR IN-VESSEL RETENTION IN HIGH POWER REACTORS

If cooling is inadequate during a reactor accident, a significant amount of core material could become molten and relocate to the lower head of the reactor vessel, as happened in the Three Mile Island Unit 2 accident. In such a case, concerns about containment failure and associated risks can be eliminated if it is possible to ensure that the lower head remains intact so that relocated core materials are retained within the vessel. Accordingly, in-vessel retention (IVR) of core melt as a key severe accident management strategy has been adopted by some operating nuclear power plants and planned for some advanced light water reactors. However, it is not clear that currently proposed external reactor vessel colling (ERVC) without additional enhancements can provide sufficient heat removal for high power reactors (i.e., reactors with power levels above 1000 MWe). Consequently, a joint United States/Korean International Nuclear Energy Research Initiative (I-NERI) has been launched to develop recommendations to improve the margin for IVR in high power reactors. This program is initially focussed on the Korean Advanced Power Reactor-1400 MWe (APR1400) design. However, recommendations will be developed that can be applied to a wide range of existing and advanced reactor designs. The recommendations will focus on modifications to enhance ERVC (improved data, vessel coatings to enhance heat removal, and an enhanced vessel/insulation configuration to facilitate water ingress and steam venting) and modifications to enhance in-vessel debris coolability (enhanced in-vessel core catcher configuration, thickness, and material). In this paper, late-phase melt conditions affecting the potential for IVR of core melt in APR1400 were established as a basis for developing the I-NERI recommendations. The selection of 'bounding' reactor accidents, simulation of those accidents using the SCDAP/RELAP5-3D^[○!C]code, and resulting latephase melt conditions are presented.

Development of an Automated Approach to Control System Design

A research effort to develop methods for automated generation of control systems that can be traced directly to the design requirements is documented. This research is being conducted under the Nuclear Energy Research Initiative for the U.S. Department of Energy. The final goal is to allow the control designer to specify only high-level requirements and stress factors that the control system must survive (e.g., a list of transients or a requirement to withstand a single failure). To this end, the “control engine” automatically selects and validates control algorithms and parameters that are optimized to the current state of the plant, and that have been tested under the prescribed stress factors. The control engine then automatically generates the control software from validated algorithms. The automated design approach also lends itself to a control system structure that captures the design requirements and permits the optimum control solution to be maintained during the plant life.

Preliminary FRAPCON-3Th Steady-State Fuel Analysis of ThO2 and UO2 Fuel Mixtures

Recent investigations into the performance and economics of mixed thoria-urania (ThO2/UO2) fuel cycles in light water reactors indicate that there may be advantages to using these fuels at high burnups. The Idaho National Engineering and Environmental Laboratory (INEEL) modified FRAPCON-3, a U.S. Nuclear Regulatory Commission-sponsored software package developed by Pacific Northwest National Laboratory for use on mixed thoria-urania fuels. The modifications constituted the first stage of fuel performance evaluations supported by the Nuclear Energy Research Initiative (NERI) project titled Advanced Proliferation Resistant, Lower Cost, Uranium-Thorium Dioxide Fuels for Light Water Reactors. The goal of this NERI project is to develop mixed ThO2/UO2 fuels that can be operated to a relatively high burnup level in current and future commercial power reactors.This paper describes in detail the INEEL’s modifications to the FRAPCON-3 thermal conductivity subroutine FTHCON and the techniques used to validate the modifications. The paper presents the general fuel design criteria used to model mixed thoria-urania fuel and a steady-state analysis of a mock thoria-urania fuel using the FRAPCON-3Th code. The paper also presents the data analyses for the mock thoria-urania fuel and offers suggestions for future upgrades and improvements to the code.

THE PCAST ENERGY STUDIES: Toward a National Consensus on Energy Research, Development, Demonstration, and Deployment Policy

▪ Abstract During the period 1995–1999, the President's Committee of Advisors on Science and Technology (PCAST) produced three major energy studies, at President Clinton's request. The panels that conducted these studies were broadly constituted from the academic, industrial, and NGO (nongovernmental organization) sectors, and their recommendations were unanimous. These efforts (a) helped lay the foundation for several major energy initiatives of the second Clinton term, including the Climate Change Technology Initiative, the Nuclear Energy Research Initiative, and the International Clean Energy Initiative; (b) helped launch energy R&D activities on methane hydrates and geological sequestration of carbon dioxide; and (c) strengthened related activities, such as the Partnership for a New Generation of Vehicles, the Partnership for Advancing Technologies in Housing, the fossil power Vision-21 Program, and the National Bioenergy Initiative. Federal budgets for research, development, demonstration, and deployment of advanced energy technologies have increased substantially over the past four years, but they still fall short of PCAST's recommendations; and a number of the PCAST recommendations on matters other than budget have yet to be fully implemented. The PCAST energy studies demonstrate the possibility of forging consensus around key energy issues and provide a foundation on which, it is hoped, the continuing pursuit of a coherent national policy on energy innovation will be able to build.

Considering the next generation of nuclear power plants

Nuclear power will be needed for future energy demands, which are expected to grow at different rates around the world. The opportunities for building new nuclear power plants around the world will be depend on need, energy demand growth, and issues related to global warming and climate change. However, four major barriers exist for the expansion of nuclear power: economics, proliferation, safety, and wate. These issues must be addressed in the ongoing research and development of nuclear energy technology and applications. The evolution of nuclear power plant technology is presented as four distinct design generations: (1) prototypes, (2) current operating plants, (3) advanced light water reactor technology, and (4) revolutionary design concepts (i.e., Generation IV) that are now under development. The U.S. DOE Nuclear Energy Research Initiative (NERI) program is focused on the research and development of Generation IV designs that are safe, economic, proliferation-resistant, and will address current waste issues. NERI provides grants for independently peer-reviewed proposals from universities, national laboratories and industry for advanced nuclear research and development. Several NERI projects awarded in 1999 are described in terms of how they remove barriers to nuclear power plant expansion. Another DOE effort, the Accelerator Transmutation of Waste program, will seek to reduce and ameliorate civilian reactor waste. The Accelerator Transmutation of Waste program will involve a six-year science-based research plan to define key technical issues. Finally, the need for international collaboration is stressed for fourth-generation nuclear power technology development.

DOE to Review Nuclear Grant

U.S. Department of Energy (DOE) officials this week announced that a special review panel will take a fresh look at the science underpinning a $100,000 award that is intended to test a new method of transforming radioactive waste into harmless byproducts--a project which critics complain is based on the questionable principles of cold fusion. The restudy represents a potentially embarrassing stumble for the department9s new $19 million Nuclear Energy Research Initiative, which DOE officials pledged would use top-notch external reviewers to pick the best projects.

原子力 新世紀の基軸エネルギーへの復活 米国ＮＥＲＩ（Ｎｕｃｌｅａｒ Ｅｎｅｒｇｙ Ｒｅｓｅａｒｃｈ Ｉｎｉｔｉａｔｉｖｅ）の活動

U.S. President's Committee of Advisors on Science and Technology (PCAST) recommended in its recent report to the President that U.S. Department of Energy should establish the Nuclear Energy Research Initiative (NERI) to provide the funding for investigator-initiated ideas to address the issues confronting nuclear energy. This paper summarizes the current status of the U.S. nuclear energy based on the PCAST report and other reports published in the last two years in the United States, and discusses consequences and meanings of NERI to Japan's research and development for nuclear energy. Utilizing the currently available resources in a more competitive, objective, and cooperative manner, Japan could have a NERI-like program, which could make substantial cantribution to, and impact on, improvement of globai energy and environment issues.

New DOE Research Program to Boost Sagging Industry

NUCLEAR POWERA $19 million competitive grants program of the Department of Energy called the Nuclear Energy Research Initiative (NERI) is aimed at developing new technologies and reinvigorating the nuclear science community, which has seen its numbers and funding dwindle in recent years. Supporters hope the program will eventually lead to technologies that prevent nuclear weapons proliferation and form the basis for cheaper, safer reactors that generate less waste. Critics, however, charge that NERI represents a handout to a mature industry that can afford its own research.