Extended MSM method to estimate the reactivity of a sub-critical core driven by an accelerator based neutron source

TY - JOUR

T1 - Extended MSM method to estimate the reactivity of a sub-critical core driven by an accelerator based neutron source

AU - Billebaud, Annick

AU - Lecouey, Jean-Luc

AU - Chevret, T.

AU - Chabod, S.

AU - Doligez, Xavier

AU - Kochetkov, Anatoly

AU - Krása, Antonin

AU - Lecolley, F.-R.

AU - Lehaut, Gregory

AU - Marie, Nathalie

AU - Messaoudi, Nadia

AU - Uyttenhove, Wim

AU - Vittiglio, Guido

AU - Wagemans, Jan

AU - Bécares, Vicente

AU - Villamarin, David

AU - Mellier, Frédéric

N1 - Score=10

PY - 2021/2/22

Y1 - 2021/2/22

N2 - The Modified Source Multiplication method is used to determine an unknown reactivity level of a reactor from a known one if one has access to the detector counting for both levels when the reactor is fed by a constant neutron source like an Am-Be source. When available, an accelerator driven source, in continuous mode, can be useful as its intensity can be tunable and then adapted to the experimental conditions. However, in that case, the MSM technique must be extended to account for an external source whose intensity, energy and angular distributions can vary from one measurement to another. In this paper, this Modified Multi-Source Multiplication (MMSM) method is applied to measurements done during the FREYA project in the GUINEVERE facility, operated with the GENEPI-3C accelerator providing a mixture of (D,T) and (D,D) neutrons. The monitoring of these sources through the detection of the associated charged particles allows the calculation of the MMSM factors and the estimate of the reactivity values. The results are compared in different configurations with the reactivity obtained with an Am-Be source or in dynamic measurements performed with GENEPI-3C. Their excellent agreement shows the possibility of using such accelerator-based neutron sources for MSM measurements when they are correctly monitored. This is of great interest for deep sub-critical level characterization for which detector count rates per source neutrons might be low.

AB - The Modified Source Multiplication method is used to determine an unknown reactivity level of a reactor from a known one if one has access to the detector counting for both levels when the reactor is fed by a constant neutron source like an Am-Be source. When available, an accelerator driven source, in continuous mode, can be useful as its intensity can be tunable and then adapted to the experimental conditions. However, in that case, the MSM technique must be extended to account for an external source whose intensity, energy and angular distributions can vary from one measurement to another. In this paper, this Modified Multi-Source Multiplication (MMSM) method is applied to measurements done during the FREYA project in the GUINEVERE facility, operated with the GENEPI-3C accelerator providing a mixture of (D,T) and (D,D) neutrons. The monitoring of these sources through the detection of the associated charged particles allows the calculation of the MMSM factors and the estimate of the reactivity values. The results are compared in different configurations with the reactivity obtained with an Am-Be source or in dynamic measurements performed with GENEPI-3C. Their excellent agreement shows the possibility of using such accelerator-based neutron sources for MSM measurements when they are correctly monitored. This is of great interest for deep sub-critical level characterization for which detector count rates per source neutrons might be low.

KW - ADS

KW - Accelerator based neutron source

KW - MSM method

KW - Reactivity monitoring

UR - https://ecm.sckcen.be/OTCS/llisapi.dll?func=ll&objId=45072472&objAction=download

U2 - 10.1051/epjconf/202124708005

DO - 10.1051/epjconf/202124708005

M3 - Article

VL - 247

SP - 1

EP - 8

JO - EPJ Web of Conferences

JF - EPJ Web of Conferences

SN - 2100-014X

M1 - 08005

T2 - 2020 - PHYSOR

Y2 - 29 March 2020 through 3 April 2020

ER -