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2026 Annual Conference
May 31–June 3, 2026
Denver, CO|Sheraton Denver
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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!
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Modernizing I&C for operations and maintenance, one phase at a time
The two reactors at Dominion Energy’s Surry plant are among the oldest in the U.S. nuclear fleet. Yet when the plant celebrated its 50th anniversary in 2023, staff could raise a toast to the future. Surry was one of the first plants to file a subsequent license renewal (SLR) application, and in May 2021, it became official: the plant was licensed to operate for a full 80 years, extending its reactors’ lifespans into 2052 and 2053.
Frank Wols, Jan Leen Kloosterman, Danny Lathouwers, Tim Van Der Hagen
Nuclear Technology | Volume 186 | Number 1 | April 2014 | Pages 1-16
Technical Paper | Fission Reactors | doi.org/10.13182/NT13-14
Articles are hosted by Taylor and Francis Online.
An inherently safe thorium-breeder pebble bed reactor has great potential to improve the safety and sustainability of nuclear energy. The aim of this work is to determine the conditions under which breeding is possible in a thorium-breeder pebble bed reactor (PBR) and to present possible core designs for such a reactor. A method is developed to calculate the equilibrium core configuration of a thorium-breeder PBR, consisting of a driver channel and a breed channel. The SCALE system is used for cross-section generation and fuel depletion, and a two-dimensional (r,z)-flux profile is obtained using the DALTON neutron diffusion code. With the code scheme, the influence of several geometrical, operational, and fuel management parameters on breeding capability can be studied. Four fuel reprocessing schemes are investigated. The first scheme recycles breeder pebbles into the driver channel after some delay for additional 233Pa decay. The second scheme reprocesses the discharged breeder pebbles to make driver pebbles with higher 233U content. The third scheme also reprocesses the uranium isotopes from the discharged driver pebbles. Criticality, and thus breeding, can only be achieved in practice for this case. The fourth scheme, which adjusts the driver pebble residence time to find a critical core, is used to design a thorium-breeder PBR under practical operating conditions. A breeder reactor can even be achieved for a 150-cm core diameter, the same as for the uranium-fueled HTR-PM, but the design presented operates at a significantly lower reactor power, 71 MW(thermal) compared with 250 MW(thermal).
