Comparative assessment of methods for the reactivity measurement in subcritical systems by pulsed experiments
-
S. Canepa
Abstract
The determination of the subcriticality level for source-driven systems is an important problem that can be handled by several deterministic methods developed for the interpretation of flux signals in pulsed experiments. The paper compares the performance of several methods for different physical characteristics of the system considered and for different durations of the source pulse. The effects of the subcriticality level and of the experimental uncertainty are also investigated. Furthermore, an analysis of the influence of spatial effects is carried out. The study gives some indications on the most suitable method in a specific experimental configuration pointing out at the situations where non-conservative evaluations of the reactivity can be expected, i.e. when the system effective multiplication constant is underestimated.
Kurzfassung
Die Bestimmung des unterkritischen Niveaus für Quellen-betriebene Systeme ist ein wichtiges Problem, das mit Hilfe einer Reihe deterministischer Methoden, die für die Interpretation von Flusssignalen in gepulsten Experimenten behandelt werden kann. In der vorliegenden Arbeit wird die Leistungsfähigkeit einiger Methoden für verschiedene physikalische Eigenschaften des Systems und unterschiedliche Dauer des Quellen-Pulses betrachtet. Der Einfluss des unterkritischen Niveaus und von experimentellen Unsicherheiten wird ebenfalls untersucht. Des Weiteren wird eine Analyse des Einflusses von räumlichen Effekten durchgeführt. Die Studie gibt Hinweise für die am besten geeignete Methode bei einer speziellen experimentellen Anordnung und hebt die Situationen hervor, bei denen nicht-konservative Reaktivitätsgleichungen erwartet werden können, d.h. wann die effektive Multiplikationskonstante des Systems unterschätzt wird.
References
1Salvatores, M.; Slessarev, I.; Ritter, G.; Fougeras, P.; Tchistiakov, A.; Youinou, G.; Zaetta, A.: Long-lived radioactive waste transmutation and the role of accelerator driven (hybrid) systems. Nuclear Instruments and Methods in Physics Research A414 (1998) 510.1016/S0168-9002(98)00522-1Search in Google Scholar
2Soule, R.: Neutronic studies in support to ADS: the MUSE experiments in the MASURCA facility. Proceedings of the International Conference on the New Frontier of Nuclear Technology, PHYSOR 2002, Seoul, Korea, 2002Search in Google Scholar
3Persson, C.; Seltborg, P.; Åhlander, A.; Gudowski, W.; Stummer, T.; Kiyavitskaya, H.; Bournos, V.; Fokov, Y.; Serafimovich, I.; Chigrinov, S.: Analysis of reactivity determination methods in the subcritical experiment Yalina. Nuclear Instruments and Methods in Physics Research A, 554 (2005) 37410.1016/j.nima.2005.07.058Search in Google Scholar
4Yamane, Y.; Pázsit, I.: Heuristic derivation of Rossi-alpha formula with delayed neutrons and correlated source. Annals of Nuclear Energy25 (1998) 1373Search in Google Scholar
5Keepin, G. R.: Physics of Nuclear Kinetics, Addison-Wesley, Reading1965Search in Google Scholar
6Bell, G. I.; Glasstone, S.: Nuclear Reactor Theory, Van Nostrand Reinhold, New York, 1970Search in Google Scholar
7 Pulsed neutron research. Proceedings of the Symposium on pulsed neutron research, Karlsruhe, IAEA, Vienna, 1965Search in Google Scholar
8Sjöstrand, N. G.: Measurements on a subcritical reactor with a pulsed neutron source. Proceedings of the United Nations International Conference on the Peaceful Uses of Atomic Energy, Geneva, 1956, Vol. 5, p. 52Search in Google Scholar
9Gozani, T.: A modified procedure for the evaluation of pulsed source experiments in subcritical reactors. Nukleonik4 (1962) 348Search in Google Scholar
10Garelis, E.; Russell, J. L.: Theory of pulsed neutron source measurements. Nuclear Science and Engineering16 (1963) 263Search in Google Scholar
11Dulla, S.; Ravetto, P.; Rostagno, M. M.; Vinai, P.: Reactivity determination for subcritical systems by source-pulsed experiments. Kerntechnik67 (2002) 256Search in Google Scholar
12Canepa, S.: Interpretazione di misure di reattività mediante esperimenti dinamici nei reattori sottocritici, Master Thesis (in Italian), Politecnico di Torino, Torino 2005Search in Google Scholar
13Dulla, S.; Ravetto, P.; Rostagno, M. M.; Bianchini, G.; Carta, M.; D'Angelo, A.: Some features of spatial neutron kinetics for multiplying systems. Nuclear Science and Engineering149 (2005) 88Search in Google Scholar
14Picca, P.: Studio degli effetti della distribuzione spaziale e temporale della sorgente neutronica negli esperimenti pulsati. Thesis (in Italian), Politecnico di Torino, Torino 2003Search in Google Scholar
15Ravetto, P.; Rostagno, M. M.; VinaiP.: Inverse problem for the determination of the reactivity in pulsed experiments for subcritical systems. Transactions of the American Nuclear Society86 (2002) 426Search in Google Scholar
© 2007, Carl Hanser Verlag, München
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Wavelet techniques for the determination of the decay ratio in boiling water reactors
- Analytical and experimental investigations of shear stress in rod bundles with irregular cells
- Incineration of weapon grade plutoniumin a (DT) fusion driven hybrid reactor using various coolants
- Calculation of the pin power distribution for a thorium reactor assembly and benchmarking
- Comparative assessment of methods for the reactivity measurement in subcritical systems by pulsed experiments
- Thermal-hydraulic modeling of reactivity accidents in MTR reactors
- Prediction of the onset of flow instability in the ETRR-2 research reactor under loss of flow accident
- Time-dependent albedo problem for quadratic anisotropic scattering
- HN solutions of the time dependent linear neutron transport equation for a slab and a sphere
- Application of the UN method to the reflected critical slab problem for one-speed neutrons with forward and backward scattering
- The effects of different expansions of the exit distribution on the extrapolation length for linearly anisotropic scattering
- Technical Note
- Shadowing the earth from Lagrange Point L1
Articles in the same Issue
- Contents/Inhalt
- Contents
- Summaries/Kurzfassungen
- Summaries
- Technical Contributions/Fachbeiträge
- Wavelet techniques for the determination of the decay ratio in boiling water reactors
- Analytical and experimental investigations of shear stress in rod bundles with irregular cells
- Incineration of weapon grade plutoniumin a (DT) fusion driven hybrid reactor using various coolants
- Calculation of the pin power distribution for a thorium reactor assembly and benchmarking
- Comparative assessment of methods for the reactivity measurement in subcritical systems by pulsed experiments
- Thermal-hydraulic modeling of reactivity accidents in MTR reactors
- Prediction of the onset of flow instability in the ETRR-2 research reactor under loss of flow accident
- Time-dependent albedo problem for quadratic anisotropic scattering
- HN solutions of the time dependent linear neutron transport equation for a slab and a sphere
- Application of the UN method to the reflected critical slab problem for one-speed neutrons with forward and backward scattering
- The effects of different expansions of the exit distribution on the extrapolation length for linearly anisotropic scattering
- Technical Note
- Shadowing the earth from Lagrange Point L1
