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Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
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ANS Student Conference 2025
April 3–5, 2025
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General Kenneth Nichols and the Manhattan Project
Nichols
The Oak Ridger has published the latest in a series of articles about General Kenneth D. Nichols, the Manhattan Project, and the 1954 Atomic Energy Act. The series has been produced by Nichols’ grandniece Barbara Rogers Scollin and Oak Ridge (Tenn.) city historian David Ray Smith. Gen. Nichols (1907–2000) was the district engineer for the Manhattan Engineer District during the Manhattan Project.
As Smith and Scollin explain, Nichols “had supervision of the research and development connected with, and the design, construction, and operation of, all plants required to produce plutonium-239 and uranium-235, including the construction of the towns of Oak Ridge, Tennessee, and Richland, Washington. The responsibility of his position was massive as he oversaw a workforce of both military and civilian personnel of approximately 125,000; his Oak Ridge office became the center of the wartime atomic energy’s activities.”
Ho Seok, Hee Cheon No, Sung Jae Cho, Sang Doug Park, Hwang Young Jun, Yong Kwan Lee
Nuclear Technology | Volume 106 | Number 3 | June 1994 | Pages 384-396
Technical Paper | Reactor Operation | doi.org/10.13182/NT94-A34968
Articles are hosted by Taylor and Francis Online.
A workstation-based real-time simulator for two-loop pressurized water reactor plants is developed for classroom training in support of a full-scale simulator, on-site transient analysis, and engineering studies. The present simulator consists of three functional modules: plant module, graphic module, and man-machine interaction module. The plant module includes models for the core kinetics, reactor coolant system, steam generator, main steam line, balance of plant, and control and protection system. Each of the models is optimized to obtain the capability of real-time simulation. For simulating the thermal-hydraulic behavior of the reactor coolant system in the plant module, a fully-implicit safety analysis-2/workstation (FISA-2 /WS) is developed, which adopts implicit algorithms for their inherent stability and efficiency in solving the stiff set of equations that resulted from component models. It allows the use of a larger time step than the Courant limit without any numerical instability, and it also guarantees reasonable accuracy. And the level tracking logic and the peak cladding temperature calculation model on the basis of the simple analytical model are used to track the two-phase water level in the core and to predict the cladding temperature in the uncovered region of the core under accidents, respectively. The graphic module is designed to provide the user with more information at a glance by dynamically displaying schematic diagrams of the systems, symbols indicating the operating status of each component, trend curves, and the main control room. Especially, the CONTROL ROOM menu is designed to enable the user to perform his specific actions through the schematic diagrams of the main control panels in a way similar to which operators do them in the main control room for the KO-RI Nuclear Power Plant Unit 2. In each schematic diagram of five sections, the indicators and alarms display the various operating parameters, alarm signals, and trip signals, and the user can control the various components by operating the corresponding switches in each section through the mouse. Also, the user can initiate his actions through various system diagrams. As tools for the man-machine interface, the man-machine interaction model uses a color cathode ray tube monitor, a standard keyboard, and the mouse. The interactive communication module receives parameters from the user via the keyboard and mouse, and transfers them to the plant module so as to enable the user to perform his specific actions. This module provides the user with various initiating events (malfunctions and manual controls) through SYSTEM, CONTROL ROOM, and ACCIDENTS menus, and thus a wide range of nuclear steam supply system transients can be easily simulated. This module also enables the user to select one of the menu-driven graphic displays. The FISA-2/WS is verified through comparisons with analytical solutions, separated tests and integral tests, and predictions by RETRAN-2 and RELAP5/MOD3. Through the various tests of FISA-2/WS, it is convincing that FISA-2/WS can simulate most transients of the KO-RI Unit 2 with reasonable accuracy in real time.
