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Nuclear Installations Safety
Devoted specifically to the safety of nuclear installations and the health and safety of the public, this division seeks a better understanding of the role of safety in the design, construction and operation of nuclear installation facilities. The division also promotes engineering and scientific technology advancement associated with the safety of such facilities.
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Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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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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Christmas Night
Twas the night before Christmas when all through the houseNo electrons were flowing through even my mouse.
All devices were plugged in by the chimney with careWith the hope that St. Nikola Tesla would share.
Blair P. Bromley
Nuclear Technology | Volume 186 | Number 1 | April 2014 | Pages 17-32
Technical Paper | Fission Reactors | doi.org/10.13182/NT13-86
Articles are hosted by Taylor and Francis Online.
New fuel bundle and lattice concepts to implement thorium-based fuel cycles in pressure tube heavy water reactors (PT-HWRs) have been explored to achieve maximum resource utilization. As an existing, operational technology, PT-HWRs are highly advantageous for implementing the use of thorium-based fuel cycles because of their high neutron economy and online refueling capability. A PT-HWR is flexible in that it can use one, two, or more different types of fuels in either homogeneous or heterogeneous cores to optimize power production, fuel burnup, and new fissile fuel production. In a heterogeneous PT-HWR core, higher fissile content seed fuel will be optimized for power and excess neutron production, and lower fissile content blanket fuel will be optimized for production of 233U. Five different lattice concepts were investigated for potential use in a once-through thorium cycle in a PT-HWR. The lattices involved 43-, 35-, and 21-element bundles with a central cluster of ThO2 pins, or a Zircaloy-4 (Zr-4) central displacer tube containing either stagnant D2O coolant or solid ZrO2, to help reduce coolant void reactivity (CVR). The fuel in the outer pins is a homogeneous mixture of Th and low-enriched uranium (LEU) (~5 wt% 235U/U) or reactor-grade Pu (~67 wt% fissile). The content of the LEU or Pu was varied to achieve different levels of burnup, and it is presumed that low-reactivity fuel would be used as blanket bundles. It was found that the various lattice concepts could achieve burnups ranging from ~10 to 80 MWd/kg and that the fissile utilization could be up to 60% to 100% higher than what is currently achieved in a PT-HWR using natural uranium fuel. Burnup-averaged CVR ranges from approximately +1 to +16 mk (1 mk = 100 pcm = 0.001Δk/k), depending on lattice type and fuel composition. Assuming a maximum linear element rating of ~50 kW/m, the maximum permissible bundle power ranges from ~520 to 800 kW.
