ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Thermal Hydraulics
The division provides a forum for focused technical dialogue on thermal hydraulic technology in the nuclear industry. Specifically, this will include heat transfer and fluid mechanics involved in the utilization of nuclear energy. It is intended to attract the highest quality of theoretical and experimental work to ANS, including research on basic phenomena and application to nuclear system design.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Latest Magazine Issues
Apr 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
May 2025
Nuclear Technology
April 2025
Fusion Science and Technology
Latest News
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.”
M. T. Friend, R. F. Wright, R. Hundal, L. E. Hochreiter, M. Ogrins
Nuclear Technology | Volume 122 | Number 1 | April 1998 | Pages 19-42
Technical Paper | Reactor Safety | doi.org/10.13182/NT98-A2848
Articles are hosted by Taylor and Francis Online.
As part of the AP600 design certification program, a series of component separate effects tests and two integral systems tests of the nuclear steam supply system were performed. These tests were designed to provide data necessary to validate Westinghouse safety analysis codes for AP600 applications. In addition, the tests have provided the opportunity to investigate the thermal-hydraulic phenomena that are expected to be important in AP600 transients. One series of integral systems tests was undertaken on the SPES-2 facility in Italy, a full-height, full-pressure, 1/395th-power and -volume scale simulation of the AP600 nuclear steam supply system and passive safety features. A series of thirteen design-basis events were simulated at SPES-2 to obtain data for verification and validation of the computer models used for the safety analysis of the AP600. The modeled initiating events included a series of small-break loss-of-coolant accidents (SBLOCAs), single steam generator tube ruptures, and a main steam-line break.The results of the analyses of the SPES-2 test data, performed to investigate the performance of the safety-related systems are reported. These analyses were also designed to demonstrate, through mass and energy inventory calculations, mass and energy balances, and event timing analyses, the applicability of the SPES-2 tests for computer model verification and validation. The key thermal-hydraulic phenomena simulated in the SPES-2 tests and the performance and interactions of the passive safety-related systems that can be investigated through the SPES-2 facility are emphasized. The latter includes the impact of accumulator nitrogen and nonsafety-related system actuation on the passive safety-related system performance.It is concluded that the key thermal-hydraulic phenomena that characterize the SBLOCA and non-LOCA transients have been successfully simulated in the SPES-2 facility, and the test results can be used to validate the AP600 safety analysis computer codes. The SPES-2 tests demonstrate that the AP600 passive safety-related systems successfully combine to provide a continuous removal of core decay heat. The SPES-2 tests also showed no adverse interactions between the passive safety-related system components or with the nonsafety-related systems. In particular, it was found that the effect of noncondensable nitrogen on passive safety-related system performance was negligible.
