Natural Nuclear Reactor Oklo and Variation of Fundamental Constants Part 1: Computation of Neutronics of Fresh Core

Abstract

Using modern methods of reactor physics we have performed full-scale calculations of the natural reactor Oklo. For reliability we have used recent version of two Monte Carlo codes: Russian code MCU REA and world wide known code MCNP (USA). Both codes produce similar results. We have constructed a computer model of the reactor Oklo zone RZ2 which takes into account all details of design and composition. The calculations were performed for three fresh cores with different uranium contents. Multiplication factors, reactivities and neutron fluxes were calculated. We have estimated also the temperature and void effects for the fresh core. As would be expected, we have found for the fresh core a significant difference between reactor and Maxwell spectra, which was used before for averaging cross sections in the Oklo reactor. The averaged cross section of Sm-149 and its dependence on the shift of resonance position (due to variation of fundamental constants) are significantly different from previous results. Contrary to results of some previous papers we find no evidence for the change of the fine structure constant in the past and obtain new, most accurate limits on its variation with time: -4 10^{-17}year^{-1} < d alpha/dt/alpha < 3 10^{-17} year^{-1} A further improvement in the accuracy of the limits can be achieved by taking account of the core burnup. These calculations are in progress.

25 pages, 14 figures, 12 tables, minor corrections, typos corrected

References in corpus (1)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)

Cited by in corpus (73)

• The Confrontation between General Relativity and Experiment
• The Confrontation between General Relativity and Experiment
• Varying constants, Gravitation and Cosmology
• Teleparallel Gravity: From Theory to Cosmology
• Equivalence Principle Violations and Couplings of a Light Dilaton
• The status of varying constants: a review of the physics, searches and implications
• Exploring Cosmic Origins with CORE: Cosmological Parameters
• The UVES Large Program for Testing Fundamental Physics II: Constraints on a Change in μ Towards Quasar HE 0027-1836
• Dependence of nuclear binding on hadronic mass variation
• Primordial nucleosynthesis as a probe of fundamental physics parameters
• Breaking of the equivalence principle in the electromagnetic sector and its cosmological signatures
• Enhanced effect of quark mass variation in 229Th and limits from Oklo data
• Measuring the stability of fundamental constants with a network of clocks
• Late-time cosmology of scalar-tensor theories with universal multiplicative coupling between the scalar field and the matter Lagrangian
• Manifestations of a spatial variation of fundamental constants on atomic clocks, Oklo, meteorites, and cosmological phenomena
• Constraining the variation of fundamental constants at z ~ 1.3 using 21-cm absorbers
• Microwave and submillimeter molecular transitions and their dependence on fundamental constants
• A new approach for testing variations of fundamental constants over cosmic epochs using FIR fine-structure lines
• Variation of fundamental parameters and dark energy. A principal component approach
• Testing the violation of the equivalence principle in the electromagnetic sector and its consequences in $f(T)$ gravity
• Constraint on the time variation of the fine-structure constant with the SDSS-III/BOSS DR12 quasar sample
• Unifying cosmological and recent time variations of fundamental couplings
• Variation in the fine-structure constant, distance-duality relation and the next generation of high-resolution spectrograph
• Cosmological Effects of Scalar-Photon Couplings: Dark Energy and Varying-alpha Models
• Galaxy clusters and a possible variation of the fine structure constant
• Cosmological Evolution of Fundamental Constants: From Theory to Experiment
• Constraints on a possible variation of the fine structure constant from galaxy cluster data
• Possible variations of the fine structure constant $\alpha$ and their metrological significance
• Galaxy clusters, type Ia supernovae and the fine structure constant
• Mass freezing in growing neutrino quintessence
• Variation of $\alpha$ from a Dark Matter Force
• Varying fine-structure constant cosmography
• Competing bounds on the present-day time variation of fundamental constants
• Dark energy and Equivalence Principle constraints from astrophysical tests of the stability of the fine-structure constant
• Thomson scattering: One rate to rule them all
• Reappraisal of the limit on the variation in $\alpha$ implied by Oklo
• Current and future constraints on extended Bekenstein-type models for a varying fine-structure constant
• Oklo reactors and implications for nuclear science
• Do the fundamental constants change with time ?
• Nonlinear multidimensional gravity and the Australian dipole
• Current and future constraints on Bekenstein-type models for varying couplings
• Investigation of the fundamental constants stability based on the reactor Oklo burn-up analysis
• Cosmological and astrophysical constraints on tachyon dark energy models
• Constraints on extended Bekenstein models from cosmological, astrophysical, and local data
• Runaway dilaton models: improved constraints from the full cosmological evolution
• The variation of the fine structure constant: testing the dipole model with thermonuclear supernovae
• Variation of the fine-structure constant: an update of statistical analyses with recent data
• Astrophysical and local constraints on string theory: runaway dilaton models
• Fundamental physics with ESPRESSO: Constraints on Bekenstein and dark energy models from astrophysical and local probes
• Incompatibility of fine-structure constant variations at recombination with local observations
• Non-parametric reconstruction of the fine structure constant with galaxy clusters
• Distinguishing freezing and thawing dark energy models through measurements of the fine-structure constant
• Spatial and temporal variations of the fine-structure constant in the Finslerian universe
• Solar System planetary tests of \dot c/c
• JWST observations constrain the time evolution of fine structure constants and dark energy - electromagnetic coupling
• Revised fits to $\Delta \alpha /\alpha$ in consistency with the accelerating universe
• Variation of fundamental constants and white dwarfs
• Spatial variation of fundamental constants: testing models with thermonuclear supernovae
• Fine-structure constant constraints on late-time dark energy transitions
• Sensitivity of Tunneling-Rotational Transitions in Ethylene Glycol to Variation of Electron-to-Proton Mass Ratio
• Lutetium thermometry for Oklo natural reactors: a new look at old data
• Phasing out of Darkness: From Sterile Neutrino Dark Matter to Neutrino Masses via Time-Dependent Mixing
• Variation of the Fine-Structure Constant from the de Sitter Invariant Special Relativity
• Anthropic Selection of Physical Constants, Quantum Entanglement, and the Multiverse Falsifiability
• Time Variation of the Fine Structure Constant in the Spacetime of a Domain Wall
• Assessing the viability of successful reconstruction of the dynamics of dark energy using varying fundamental couplings
• Varying Alpha Generalized Dirac-Born-Infeld Models
• La138/139 Isotopic Data and Neutron Fluences for Oklo RZ10 Reactor
• Cosmological Consequences of Topological Defects: Dark Energy and Varying Fundamental Constants
• Constraints on the Variation of the QCD Interaction Scale ${\Lambda }_{\text{QCD}}$
• Gamma-ray fluxes in Oklo natural reactors
• Avoiding unrealistic priors: the case of dark energy constraints from the time variation of the fine-structure constant
• A speed limit on tachyon fields from cosmological and fine-structure data