Determination of Large Negative Reactivity by Integral Versions of Various Experimental Methods

Akino, Fujiyoshi; Yasuda, Hideshi; Kaneko, Yoshihiko

doi:10.1080/18811248.1980.9732629

“…By comparing Eqs. (1) and (9), the change in the neutron flux distribution from 0 to is considered to be caused by the emergence of neutron source I, rather than the change in the operators. For simplification of the notation, operator É is defined as an operator that satisfies the following relationship on any neutron source Qðx; EÞ:…”

Section: Theory Of the Imaginary Neutron Source 1 Concept Of Thementioning

confidence: 99%

“…Several methods of subcriticality measurement have been developed for formulating the relationship between the subcriticality and neutron flux in the steady state. The higher-mode source multiplication method, 5,6) the fundamental-mode extraction method, 7) and the integral method 8,9) are improved versions of the conven-tional neutron source multiplication method. However, these methods do not provide a sufficiently accurate estimate of the subcriticality because they employ assumptions that are sometimes invalid.…”

Section: Introductionmentioning

confidence: 99%

A New Experimental Correction Method for the First-Order Perturbation Approximation in the Steady Subcritical Reactor

KAWAGUCHI

¹

,

Misawa

²

,

Pyeon

³

et al. 2010

J. Nucl. Sci. Technol.

0

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In the subcritical nuclear reactor, the subcriticality is closely related with the neutron flux distribution. Since the relationship between them is complex, the subcriticality measurement by conventional methods involves some difficulties, particularly when the subcriticality is large. A new subcriticality measurement method is proposed for the steady subcritical state. By this method, the relative distribution of the change in neutron flux between before and after the perturbation is numerically calculated. On the other hand, the amplitude of the perturbation is estimated from the count rates of neutron detectors. By this combination of the calculation and experiment, the subcriticality can be accurately estimated, to the extent that the perturbation is qualitatively known beforehand. One of the advantages of this method over the conventional modified neutron source multiplication method is that numerical calculations are only executed on unperturbed states. In addition, the completeness of the eigenfunctions is not assumed. The validity of this method is confirmed through the numerical calculation.

show abstract

“…Several methods of subcriticality measurement have been developed for formulating the relationship between the subcriticality and neutron flux in the steady state. The higher-mode source multiplication method, 5,6) the fundamental-mode extraction method, 7) and the integral method 8,9) are improved versions of the conventional neutron source multiplication method. However, these methods do not provide a sufficiently accurate estimate of the subcriticality because they employ assumptions that are sometimes invalid.…”

Section: Introductionmentioning

confidence: 99%

A New Experimental Correction Method for the First-Order Perturbation Approximation in the Steady Subcritical Reactor

KAWAGUCHI

¹

,

Misawa

²

,

Pyeon

³

et al. 2010

Journal of Nuclear Science and Technology

1

0

View full text Add to dashboard Cite

In the subcritical nuclear reactor, the subcriticality is closely related with the neutron flux distribution. Since the relationship between them is complex, the subcriticality measurement by conventional methods involves some difficulties, particularly when the subcriticality is large. A new subcriticality measurement method is proposed for the steady subcritical state. By this method, the relative distribution of the change in neutron flux between before and after the perturbation is numerically calculated. On the other hand, the amplitude of the perturbation is estimated from the count rates of neutron detectors. By this combination of the calculation and experiment, the subcriticality can be accurately estimated, to the extent that the perturbation is qualitatively known beforehand. One of the advantages of this method over the conventional modified neutron source multiplication method is that numerical calculations are only executed on unperturbed states. In addition, the completeness of the eigenfunctions is not assumed. The validity of this method is confirmed through the numerical calculation.

show abstract

Detection of subcriticality changes by Simmons-King and Sjöstrand methods

Kitamura

¹

,

Misawa

²

2020

Annals of Nuclear Energy

0

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Determination of Large Negative Reactivity by Integral Versions of Various Experimental Methods

Cited by 11 publications

References 5 publications

A New Experimental Correction Method for the First-Order Perturbation Approximation in the Steady Subcritical Reactor

A New Experimental Correction Method for the First-Order Perturbation Approximation in the Steady Subcritical Reactor

A New Experimental Correction Method for the First-Order Perturbation Approximation in the Steady Subcritical Reactor

Detection of subcriticality changes by Simmons-King and Sjöstrand methods

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