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detector for neutron resonance densitometryTsuchiya, Harufumi; Harada, Hideo; Koizumi, Mitsuo; Kitatani, Fumito; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Becker, B.*; Kopecky, S.*; Schillebeeckx, P.*
Proceedings of 35th ESARDA Annual Meeting (Internet), 7 Pages, 2013/05
Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Takamine, Jun; Kureta, Masatoshi; Iimura, Hideki; Seya, Michio; Becker, B.*; Kopecky, S.*; et al.
Proceedings of 35th ESARDA Annual Meeting (Internet), 6 Pages, 2013/05
The neutron resonance densitometry (NRD) has been proposed to quantify of nuclear materials in particle-like debris of melted fuel formed in severe accidents of nuclear reactor such as Fukushima Daiichi Nuclear Power Plants; the NRD is a combined method of NRTA (neutron resonance transmission analysis) and NRCA (neutron resonance capture analysis) using a pulsed neutron generator and a neutron TOF (time of flight) technique. The presentation includes the proposed NRD concept, its principle, and preliminary analytical studies on achievable accuracies. The research plan on the feasibility study of the NRD will be also shown, which has been started since 2012 JFY.
-ray beam for nuclear materials in debris of melted fuelShizuma, Toshiyuki; Hajima, Ryoichi; Hayakawa, Takehito; Angell, C.; Minato, Futoshi; Suyama, Kenya; Seya, Michio
Proceedings of 35th ESARDA Annual Meeting (Internet), 6 Pages, 2013/05
Nondestructive assay (NDA) of actinide nuclei in spent nuclear fuel or melted fuel using a -ray beam is possible using a scattered method or a transmission method. These methods use nuclear resonance fluorescence (NRF) which is a process of nuclear excitation by photo-absorption and de-excitation by photo-emission. In the scattered method, system performance such as counting precision is affected by radiation background from the spent fuel and can be improved by using resonances at high energies where an optimum signal-to-noise ratio is obtained. In this talk, we will show calculated results on statistical uncertainties of the scattered method for various NRF cross sections in the range of 3 to 100 eV barn at excitation energies between 2 and 5 MeV. We will also mention the methodology of the transmission (self-interrogation) measurement and recent experimental results obtained using a quasi-monochromatic -ray beam.
Bolind, A.
Proceedings of 35th ESARDA Annual Meeting (Internet), 17 Pages, 2013/05
Reactor noise analysis and neutron coincidence/multiplicity analysis both examine the non-random clustering of neutrons in time, caused by the simultaneous emission of multiple neutrons from each fission event and by the correlation of successive fissions in the same fission chain. Despite these same physical origins, the various kinds of techniques are not often compared with each other on an intuitive level. This paper makes this comparison, primarily by examining whether a given technique relies on the joint probability of detecting neutrons or on the conditional probability. The techniques are compared in other ways, too, such as their time scales and how they deal with fission chains. Subtleties are also addressed, such as the time origin of the Rossi-alpha diagram and the taking of moments. Specific instruments are not described in detail; the focus is the understanding of the physics and counting principles.
Seya, Michio; Harada, Hideo; Kitatani, Fumito; Koizumi, Mitsuo; Tsuchiya, Harufumi; Hajima, Ryoichi; Hayakawa, Takehito; Shizuma, Toshiyuki; Angell, C.; Bolind, A.
Proceedings of 35th ESARDA Annual Meeting (Internet), 9 Pages, 2013/05
This introductory paper presents two promising NDA technologies for nuclear material accountancy of melted fuel debris of Fukushima Daiichi NPP, which JAEA has been developing basic part of them. One of the two is Neutron Resonance Densitometry based on NRTA and NRCA utilizing the Time of Flight method, which is intended for the analysis of particle-like debris. We JAEA and JRC-IRMM have started collaboration on NRD since May 2012. This paper describes the proposed NRD very roughly, while the some of the papers show the details of this method. Another NDA technology uses LCS -rays to analyse nuclear material in cut / small rock-like debris. The application of the Nuclear Resonance Fluorescence method using LCS -rays is presented here very roughly. Last 2 papers in this series show in detail the demonstration system of generation of intense mono-energetic -rays using Energy Recovery Linac and laser storing cavity and measurement methods.
Becker, B.*; Harada, Hideo; Kauwenberghs, K.*; Kitatani, Fumito; Koizumi, Mitsuo; Kopecky, S.*; Moens, A.*; Schillebeeckx, P.*; Sibbens, G.*; Tsuchiya, Harufumi
Proceedings of 35th ESARDA Annual Meeting (Internet), 7 Pages, 2013/05
Schillebeeckx, P.*; Abousahl, S.*; Becker, B.*; Borella, A.*; Emiliani, F.*; Harada, Hideo; Kauwenberghs, K.*; Kitatani, Fumito; Koizumi, Mitsuo; Kopecky, S.*; et al.
Proceedings of 35th ESARDA Annual Meeting (Internet), 11 Pages, 2013/05