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Albuquerque, NM|The University of New Mexico
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Penn State and Westinghouse make eVinci microreactor plan official
Penn State and Westinghouse Electric Company are working together to site a new research reactor on Penn State’s University Park, Pa., campus: Westinghouse’s eVinci, a HALEU TRISO-fueled sodium heat-pipe reactor. Penn State has announced that it submitted a letter of intent to host and operate an eVinci reactor to the Nuclear Regulatory Commission on February 28 and plans to engage with the NRC on specific siting decisions. Penn State already boasts the Breazeale reactor, which began operating in 1955 as the first licensed research reactor at a university in the United States. At 70, the Breazeale reactor is still in operation.
H. A. Sandmeier, D. M. O’Shea
Nuclear Science and Engineering | Volume 5 | Number 3 | March 1959 | Pages 186-189
Technical Paper | doi.org/10.13182/NSE59-A25575
Articles are hosted by Taylor and Francis Online.
From the time dependent heat conduction and temperature distribution, an expression is derived for the time constant in a cylindrical fuel pin and cladding with axial coolant flow. The power production and the inlet temperature are functions of time. In the radial direction perfect mixing of the coolant is assumed. The average coolant temperature in a region is the average between inlet and outlet temperature assuming a linear rise in the axial direction. The set of partial differential equations can be solved by means of Laplace transform. The reciprocal of the roots of the characteristic equation for the temperature in the transform domain represents the time constants. The smallest root represents the dominant transient time constant. This dominant time constant is compared with a qualitative expression for the thermal relaxation time of a reactor after a power change given by Bethe. The numerical example used is a fuel pin in EBR-I Mark III in flowing NaK coolant at a core power generation of 1 Mw at various coolant flow conditions.