New measurement system for on line in core high-energy neutron flux monitoring in materials testing reactor conditions

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/1.3554439· OSTI ID:22062273

Geslot, B; Filliatre, P; Barbot, L; Jammes, C; Breaud, S; Oriol, L; Villard, J -F ^[1]; Vermeeren, L ^[2]; Lopez, A Legrand ^[3]

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1. CEA, DEN, Cadarache, SPEx/LDCI, F-13108 Saint-Paul-lez-Durance (France)
2. SCK-CEN, Boeretang 200, B-2400 Mol (Belgium)
3. CEA, DEN, Saclay, SIREN/LECSI, F-91400 Saclay (France)

Flux monitoring is of great interest for experimental studies in material testing reactors. Nowadays, only the thermal neutron flux can be monitored on line, e.g., using fission chambers or self-powered neutron detectors. In the framework of the Joint Instrumentation Laboratory between SCK-CEN and CEA, we have developed a fast neutron detector system (FNDS) capable of measuring on line the local high-energy neutron flux in fission reactor core and reflector locations. FNDS is based on fission chambers measurements in Campbelling mode. The system consists of two detectors, one detector being mainly sensitive to fast neutrons and the other one to thermal neutrons. On line data processing uses the CEA depletion code DARWIN in order to disentangle fast and thermal neutrons components, taking into account the isotopic evolution of the fissile deposit. The first results of FNDS experimental test in the BR2 reactor are presented in this paper. Several fission chambers have been irradiated up to a fluence of about 7 x 10{sup 20} n/cm{sup 2}. A good agreement (less than 10% discrepancy) was observed between FNDS fast flux estimation and reference flux measurement.

• OSTI ID: 22062273
• Journal Information: Review of Scientific Instruments, Vol. 82, Issue 3; Other Information: (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
BR-2 REACTOR
DATA PROCESSING
FAST NEUTRONS
FISSION CHAMBERS
IN CORE INSTRUMENTS
NEUTRON DETECTION
NEUTRON FLUX
NEUTRON REFLECTORS
REACTOR CORES
SELF-POWERED NEUTRON DETECTORS
THERMAL NEUTRONS