Critical Studies for the French Fast Reactor "RAPSODIE" (ZPR-3 Assembly 44)

Technical Report · Tue Mar 01 04:00:00 EST 1966

DOI:https://doi.org/10.2172/4466774· OSTI ID:4466774

Hess, A. L. ^[1]; Keeney, W. P. ^[1]; Caumette, P. ^[2]; Boyer, J. P. ^[2]

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1. Argonne National Lab., Idaho Falls, ID (United States)
2. Centre d'Etudes Nucleaires de Cadarache (France)

A program of critical studies was carried out on ZPR-3 with a mockup of the French fast reactor, RAPSODIE. Objectives of the program included the acquisition of critical data pertinent to the fuel specification for RAPSODIE, the evaluation of the RAPSODIE design control systems, and the collection of other data useful in verifying calculational techniques. The RAPSODIE core simulated in the mockup was approximately a 40-liter cylinder containing 40 v/o fuel (a PuO₂-UO₂ mixture), 34 v/o sodium, and 20 v/o steel. The experiments were done in two phases: a physics-core study, and an engineering-core study. For the physics-core study, a simple core-blanket arrangement was constructed for ease of calculation, and spectral indices and local reactivity coefficients were measured. In the fuel for the physics-core mockup, the ratio of uranium to plutonium was about 5: 1, with the uranium enriched to 60 a/o. Both radial and axial blankets had a composition equivalent to about 45 v/o uranium, 30 v/o sodium, and 15 v/o steel. In the fuel for the engineering core, the uranium-to-plutonium ratio was reduced. to 3.2: 1, with the uranium 62 a/o enriched. Mockups of the RAPSODIE axial regions, steel-sodium end gaps, and different axial blankets were constructed with the engineering core, along with mockups of the RAPSODIE control and safety rods. Experiments in the full engineering mockup included rod-worth studies, material-reactivity-coefficient measurements, and traverses of neutron detectors and fuel reactivity samples. This was the first ZPR-3 critical assembly to contain a significant loading of plutonium, and the problems introduced thereby were investigated. Heat generation from alpha decay of the plutonium affected the accuracy of reactivity measurements, and the neutron source from spontaneous fission required different techniques for measuring reactor periods.

• Research Organization: Argonne National Laboratory (ANL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA), Nuclear Criticality Safety Program (NCSP); US Atomic Energy Commission (AEC)
• DOE Contract Number: W-31109-ENG-38
• NSA Number: NSA-21-005597
• OSTI ID: 4466774
• Report Number(s): ANL-7044
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
42 ENGINEERING
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALPHA DECAY
BLANKETS
CONFIGURATION
CONTROL
CRITICAL ASSEMBLIES
CRITICALITY
Core Configuration
Critical Experiment
DESIGN
FISSION
FUELS
LIQUID METAL COOLANT
LOADING
NEUTRON DETECTION
Nuclear Criticality Safety Program (NCSP)
PLUTONIUM
PLUTONIUM OXIDES
Physics-Core
RAPSODIE
REACTIVITY
REACTOR CORE
REACTORS
RESEARCH REACTORS
RODS
Reactivity Coefficient
SAFETY
SHUTDOWN
SODIUM
SPECTRA
STEELS
Traverses
URANIUM
URANIUM DIOXIDE
ZPR-3