3.4 Summary
In this work, we proposed a new concept of the “self-indication method” as a
complementary nondestructive assay for the fuel debris of Fukushima Daiichi NPP.
We carried out experimental validation for application of the self-indication
method. It was confirmed that the area density (thickness of the target nuclide)
can be determined within 3 % accuracy by simple area analysis without a resonance
fitting process. Moreover, it was experimentally shown that the contribution from
the other nuclide can be remarkably suppressed by applying the self-indication
method. The self-indication method combined with the TOF technique will be a
useful tool for nondestructive assaying of the distribution of nuclear material in the
melted fuel debris, which contains many impurities and has high activities.
Acknowledgments This work was supported by JSPS KAKENHI Grant Number 24760714.
Open Access This chapter is distributed under the terms of the Creative Commons Attribution
Noncommercial License, which permits any noncommercial use, distribution, and reproduction in
any medium, provided the original author(s) and source are credited.
m
U-nat indicator, No sample
U-nat indicator, U-nat, Np-237, Am-243
U-nat indicator, U-nat
Fig. 3.8 TOF spectra obtained with the self-indication method for
nat U and mixture of
nat
U,
237
Np,
and
243
Am
28
J. Hori et al.
In this work, we proposed a new concept of the “self-indication method” as a
complementary nondestructive assay for the fuel debris of Fukushima Daiichi NPP.
We carried out experimental validation for application of the self-indication
method. It was confirmed that the area density (thickness of the target nuclide)
can be determined within 3 % accuracy by simple area analysis without a resonance
fitting process. Moreover, it was experimentally shown that the contribution from
the other nuclide can be remarkably suppressed by applying the self-indication
method. The self-indication method combined with the TOF technique will be a
useful tool for nondestructive assaying of the distribution of nuclear material in the
melted fuel debris, which contains many impurities and has high activities.
Acknowledgments This work was supported by JSPS KAKENHI Grant Number 24760714.
Open Access This chapter is distributed under the terms of the Creative Commons Attribution
Noncommercial License, which permits any noncommercial use, distribution, and reproduction in
any medium, provided the original author(s) and source are credited.
m
U-nat indicator, No sample
U-nat indicator, U-nat, Np-237, Am-243
U-nat indicator, U-nat
Fig. 3.8 TOF spectra obtained with the self-indication method for
nat U and mixture of
nat
U,
237
Np,
and
243
Am
28
J. Hori et al.