Design study to increase plutonium conversion ratio of hc-flwr core

Akifumi Yamaji, Yoshihiro Nakano, Sadao Uchikawa, Tsutomu Okubo

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The innovative water reactor for flexible fuel cycle (FLWR) is an advanced reactor concept based on the well-developed light water reactor (LWR) technology. It is to be introduced in two stages to achieve effective and flexible utilization of the uranium and plutonium resources. In the first stage, the high-conversion-type reactor concept (HC-FLWR) is to be introduced, with a core that achieves a fissile Pu conversion ratio of 0.84. Then, in the second stage, the reduced-moderation water reactor (RMWR) concept can be introduced, with a breeder-type core that achieves a fissile Pu conversion ratio of 1.05. From the viewpoint of effective introduction of the high-conversion-type reactor, such as the introduction capacity of the reactor, HC-FLWR is required to further raise the fissile Pu conversion ratio to ∼0.95. This study aims to develop a new core design concept for the high-conversion-type core, HC-FLWR +, to achieve the higher fissile Pu conversion ratio of ∼0.95 under the framework of UO 2 and U-Pu mixed-oxide (MOX) fuel technologies for LWRs. For raising the fissile Pu conversion ratio and controlling the void reactivity characteristics of the core, the concept of FLWR/ MIX fuel assembly, which uses MOX and enriched UO 2fuel rods, is utilized. The relationships between the main design parameters and the core performance index parameters are clarified in this study. When the fuel rod diameter and the clearance range from 1.23 to 1.28 cm and 0.25 to 0.20 cm, respectively, under the same pitch of 1.48 cm, the fissile Pu conversion ratio and the core average discharge burnup range from 0.89 to 0.94 and 53 to 49 GWd/tonne, respectively (the fissile Pu conversion ratio and the burnup are subject to a trade-off). Furthermore, when 235U enrichment in the UO 2 fuel rods is increased from 4.9 to 6 wt%, the fissile Pu conversion ratio improves to 0.97. From these relationships, two representative core designs with fissile Pu conversion ratios of 0.91 and 0.94 and one optional design with a ratio of 0.97 were obtained. Hence, the flexibility of HC-FLWR + concept to achieve a higher fissile Pu conversion ratio of ∼0.95 has been revealed. Together with the standard HC-FLWR design, the concept covers a wide range of needs on fissile Pu conversion ratio from 0.84 up to 0.97, with design variations that are expected to be within the scope of current boiling water reactor and MOX fuel technologies.

Original languageEnglish
Pages (from-to)309-322
Number of pages14
JournalNuclear Technology
Volume179
Issue number3
Publication statusPublished - 2012 Sep
Externally publishedYes

Fingerprint

plutonium
Plutonium
Mixed oxide fuels
reactors
mixed oxides
Boiling water reactors
Light water reactors
rods
Uranium
Water
reactor technology
boiling water reactors
Oxides
light water reactors
nuclear fuels
clearances
water
uranium
voids
resources

Keywords

  • BWR
  • Flwr/ mix fuel assembly
  • HC-FLWR

ASJC Scopus subject areas

  • Nuclear Energy and Engineering
  • Condensed Matter Physics
  • Nuclear and High Energy Physics

Cite this

Yamaji, A., Nakano, Y., Uchikawa, S., & Okubo, T. (2012). Design study to increase plutonium conversion ratio of hc-flwr core. Nuclear Technology, 179(3), 309-322.

Design study to increase plutonium conversion ratio of hc-flwr core. / Yamaji, Akifumi; Nakano, Yoshihiro; Uchikawa, Sadao; Okubo, Tsutomu.

In: Nuclear Technology, Vol. 179, No. 3, 09.2012, p. 309-322.

Research output: Contribution to journalArticle

Yamaji, A, Nakano, Y, Uchikawa, S & Okubo, T 2012, 'Design study to increase plutonium conversion ratio of hc-flwr core', Nuclear Technology, vol. 179, no. 3, pp. 309-322.
Yamaji, Akifumi ; Nakano, Yoshihiro ; Uchikawa, Sadao ; Okubo, Tsutomu. / Design study to increase plutonium conversion ratio of hc-flwr core. In: Nuclear Technology. 2012 ; Vol. 179, No. 3. pp. 309-322.
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