### Abstract

Original language | English |
---|---|

Pages (from-to) | 425-431 |

Journal | Annals of Nuclear Energy |

Volume | 35 |

Issue number | 3 |

DOIs | |

Publication status | Published - 2008 |

MoE publication type | A1 Journal article-refereed |

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*Annals of Nuclear Energy*,

*35*(3), 425-431. https://doi.org/10.1016/j.anucene.2007.07.011

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*Annals of Nuclear Energy*, vol. 35, no. 3, pp. 425-431. https://doi.org/10.1016/j.anucene.2007.07.011

**Application of importances or weight windows in MCNP4C to a geometry similar to an ITER equatorial port.** / Wasastjerna, Frej (Corresponding Author).

Research output: Contribution to journal › Article › Scientific › peer-review

TY - JOUR

T1 - Application of importances or weight windows in MCNP4C to a geometry similar to an ITER equatorial port

AU - Wasastjerna, Frej

PY - 2008

Y1 - 2008

N2 - Neutron streaming through the gap between a port plug and the port walls will be a major contributor to the shutdown dose rate in ITER, and calculating this streaming requires very effective variance reduction. The article describes a way of estimating importances for a calculation of the fast neutron flux, which will then generate weight windows. If necessary, these can be refined iteratively. Once the fast neutron calculation works well, the weight windows can be extended to lower energies and to photons using appropriate factors for which some values are suggested here. Again, these weight windows can be improved iteratively. Test runs in a simplified geometry performed fairly well, though optimizing performance simultaneously for the gamma flux at the end of the port and above it is difficult.

AB - Neutron streaming through the gap between a port plug and the port walls will be a major contributor to the shutdown dose rate in ITER, and calculating this streaming requires very effective variance reduction. The article describes a way of estimating importances for a calculation of the fast neutron flux, which will then generate weight windows. If necessary, these can be refined iteratively. Once the fast neutron calculation works well, the weight windows can be extended to lower energies and to photons using appropriate factors for which some values are suggested here. Again, these weight windows can be improved iteratively. Test runs in a simplified geometry performed fairly well, though optimizing performance simultaneously for the gamma flux at the end of the port and above it is difficult.

U2 - 10.1016/j.anucene.2007.07.011

DO - 10.1016/j.anucene.2007.07.011

M3 - Article

VL - 35

SP - 425

EP - 431

JO - Annals of Nuclear Energy

JF - Annals of Nuclear Energy

SN - 0306-4549

IS - 3

ER -