Maintaining a Critical Spectra within Monteburns for a Gas-Cooled Reactor Array by Way of Control Rod Manipulation

Journal Article · Sat Oct 01 00:00:00 EDT 2016 · Annals of Nuclear Energy (Oxford)

DOI:https://doi.org/10.1016/j.anucene.2016.05.025· OSTI ID:1304720

Adigun, Babatunde John ^[1]; Fensin, Michael Lorne ^[1]; Galloway, Jack D. ^[1]; Trellue, Holly Renee ^[1]

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1. Los Alamos National Laboratory

Our burnup study examined the effect of a predicted critical control rod position on the nuclide predictability of several axial and radial locations within a 4×4 graphite moderated gas cooled reactor fuel cluster geometry. To achieve this, a control rod position estimator (CRPE) tool was developed within the framework of the linkage code Monteburns between the transport code MCNP and depletion code CINDER90, and four methodologies were proposed within the tool for maintaining criticality. Two of the proposed methods used an inverse multiplication approach - where the amount of fissile material in a set configuration is slowly altered until criticality is attained - in estimating the critical control rod position. Another method carried out several MCNP criticality calculations at different control rod positions, then used a linear fit to estimate the critical rod position. The final method used a second-order polynomial fit of several MCNP criticality calculations at different control rod positions to guess the critical rod position. The results showed that consistency in prediction of power densities as well as uranium and plutonium isotopics was mutual among methods within the CRPE tool that predicted critical position consistently well. Finall, while the CRPE tool is currently limited to manipulating a single control rod, future work could be geared toward implementing additional criticality search methodologies along with additional features.

• Research Organization: Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Office of Defense Nuclear Nonproliferation
• Grant/Contract Number: AC52-06NA25396
• OSTI ID: 1304720
• Alternate ID(s): OSTI ID: 1324003
• Report Number(s): LA-UR-16-22226
• Journal Information: Annals of Nuclear Energy (Oxford), Vol. 96; ISSN 0306-4549
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
Criticality search
Critical spectra
Monteburns
Gas cooled reactors