Reanalysis of the Gas-cooled fast reactor experiments at the zero power facility Proteus – Spectral indices

Abstract

Abstract. PROTEUS is a zero power reactor at the Paul Scherrer Institute which has been employed during the 1970's to study experimentally the physics of the gas-cooled fast reactor. Reaction rate distributions, flux spectrum and reactivity effects have been measured in several configurations featuring PuO 2 /UO 2 fuel, absorbers, large iron shields, and thorium oxide and thorium metal fuel either distributed quasihomogeneously in the reference PuO 2 /UO 2 lattice or introduced in the form of radial and axial blanket zones. This papers focus on the spectral indices -including fission and capture in 232 Th and 237 Np -measured in the reference PuO 2 /UO 2 lattices and their predictions with an MCNPX model specially developed for the PROTEUS-GCFR core. Predictions were obtained with JEFF-3.1 and -3.11, ENDF/B-VII.0 and VII.1, and JENDL-3.3 and -4.0. A general good agreement was demonstrated. The ratio of 232 Th fission to 239 Pu fission, however, was under-predicted by 8.7±2.1% and 6.5±2.1% using ENDF/B-VII.0 and VII.1, respectively. Finally, the capture rates in 237 Np tended to be underpredicted by the JEFF and JENDL libraries, although the new cross section in JEFF-3.1.1 slightly improved the 237 Np capture to 239 Pu fission results (3.4±2.4%).

Systematics of Nd cumulative fission yields for neutron-induced fission of 235U, 238U, 238Pu, 239Pu, 240Pu and 241Pu

“…It can be estimated with fission indices measured in fast critical mock-up reactors. Weighted averages of few calculated-to-experimental ratios measured in the MASURCA [12], PROTEUS [13,14] and FCA [16] facilities have led to the following correction terms for the 238 U(n,f), 238 Pu(n,f),…”

Gas-cooled Fast Reactor Research and Development Roadmap

“…Their gas-cooled fast reactor (GCFR) would have produced 835 MW of thermal power with mixed oxide fuel arranged in pins and a coolant outlet temperature of 550°C [4]. The experimental program supporting GCFR development included critical reactor investigations under GCFR-PROTEUS (1972 through 1979) that were aimed at validating data sets and calculational methods for the design of fast breeder reactors cooled with gas [5,6,7,8]. In the late 1960s, Germany proposed various concepts with pin-type fuel in stainless-steel cladding, a pressurized concrete pressure vessel, and driving a steam cycle.…”