Neutronic coupling

Data from the (o,p) reaction [77Mel6[ were used for obtaining Gij= 2J +1)/ 21 + l))-Sij by the assumption that the reaction proceeds by triton cluster transfer with two neutrons coupled to 0+ the same proton configuration as in the ( He,d) work [71Mall] was used [91Si02] normalization constant N=1100 in the expression da/dfle p= NGejda/dClDWBA/ - - i-) was used. 

The response of foe array multiplication factor to changes in the radius of the units was explored and furnishes an internally consistent relationship allowing prescribed minimum reactivity adjustments to be made for environmental conditions Jn this way margins of safety arc e iq)resslble in terms of foe array reactivity. For example, the effects of. concrete as a reflector of an array and its Influence on neutron coupled arrays were investigated for several thicknesses of concrete. Also,... 

Experimental Measurements with Arrays of U(97.7)F6 Neutron-Coupled Through Concrete, J. r. Thomas (VCC OB)... 

KENO calculations to evaluate the neutron interaction between the stacker and other nearby units were performed for varying accumulations of uranium. These calculations demonstrated the subcriticality of the interaction systems in the unlikely event of optimum water moderation introduced throughout the system. Optimum moderation within the pellet stacker was determined to account for 8% of the system reactivity. It was further demonstrated that the contribution to the system reactivity by a dry stacker was negligible 1.5%). This small reactivity increase is attributed more to neutron reflection provided by the pellet stacker than to neutron coupling between the stacker and the other units. 

In both lanthanides and actinides the levels may be characterized by the notation Spin-orbit transitions are those between levels with the same value of L and S but different values of J. Since the neutron couples directly to the J quantum number, dipole transitions correspond to AJ = 1. The cross section is finite at Q = 0, but for increasing Q falls i jo) — in intensity, where the (70) and (72) functions are Bessel transforms... 

Neutron scattering is an excellent probe (Cribier et al. 1964) of flux lattices in superconductors because the dipole moment of the neutron couples to the magnetic field inhomogeneities associated with such lattices. Of course, the length scales for the... 

The COREBN module implemented in the SRAC system provides linear interpolation of a macroscopic cross section as a function of bumup state. It also offers two additional variables reserved for additional neutronic coupling. One of those parameters is used for the thermal-hydraulic coupling with the coolant density. The macroscopic cross sections are provided for the coupled calculation for several given states of the coolant densities. Eight coolant densities from 0.001 to 0.8 g/cc are used for the thermal-hydraulic coupling to cover the whole core. The COREBN module, then, linearly interpolates the macroscopic cross sections with respect to both bumup and coolant density. 

Generally, the local power peaking factor in a fuel assembly of conventional LMFBRs is small due to the longer mean free path of neutrons and better neutronic coupling. However, the local power peaking factor of the Super FR is rather high. 

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