Iclock 2500 code#

A free-field data input format facilitates problem preparation. Cross sections can be input on cards, from an ANISN-type nuclide-organized data set, or from a special group-organized data set which is valuable for very large cross section sets. The program has two levels of external storage utilization in order to adapt to various problem requirements efficiently. increasing spatial mesh size supplies solutions which are always reasonable overestimates of the exact solution and its numerical behaviour is more stable and coherent than the mixed mode.Įxperience up to now from several deep penetration problems in (r,z) and (x,y) geometry shows that, while for neutrons the exponential model almost always works very well, for gamma rays its behaviour may be critical and in some cases there is lack of convergence.įlexible dimensioning is used throughout so that only the total storage requirement for a given problem is of concern. improves convergence rate in most neutron deep-penetration problems and, for any practical spatial discretization, always requires CPU times not only smaller than those required by DOT-3 mixed (linear + step fixup) model, but also shorter (generally 10-20%) than the times required by DOT-3.5 weighted difference model ģ.

always gives positive solutions and does not require any fixup techniques provided that the source is non-negative Ģ. Convergence can be accelerated by several optional schemes, including a pointwise rescaling technique.ĭOT-3.5/E: Differs from DOT-3.5 in that exponential supplementary equations, as well as the usual diamond and weighted schemes, may be used to find the mesh-centre flux from the fluxes at the faces of the mesh.ġ. Anisotropic scattering is treated using a Legendre expansion of arbitrary order. The method of discrete ordinates is used.īalance equations are solved for the density of particles moving along discrete directions in each cell of a two-dimensional spatial mesh. GRTUNCL calculates an analytical first-collision source for subsequent use in DOT. TPERT is coupled to VIP which generates adjoint forward fux tables using DOT-3 scalar flux tape information.

Iclock 2500 code#

TPERT is a perturbation code to obtain exact and first-order reactivity changes. Since DOT diffusion theory does not directly calculate these gradients, it was necessary to calculate the needed quantities external to the DOT code. In order to calculate the reactivity associated with changes in reactor compositions using diffusion theory, it is necessary to fold not only the scalar fluxes with the appropriate cross sections, but also the average flux gradients with the diffusion coefficients.

In conjunction with VIP and TPERT, it allows the use of diffusion theory fluxes to obtain exact and first-order perturbation reactivity changes. VIP is a program for cross section sensitivity analysis using two- dimensional discrete ordinates transport calculations.ĭGRAD calculates the directional flux gradients from DOT-3 diffusion theory flux tapes. Numerous edits and output data sets for subsequent use are available.ĭOT-3.5 improves the space-scaling algorithm.ĭOT-3.5/CAB contains group by group UPSCATTER scaling method.ĭUCT calculates perturbations to the scalar flux caused by the presence of ducts filled with coolant. Searches on multiplication factor, time absorption, nuclide concentration, and zone thickness are available for reactor problems. Both homogeneous andexternal-source problems can be solved.

Principal applications are to neutron and/or photon transport, although the code can be applied to transport problems for any particles not subject to external force fields. DOT solves the Boltzmann transport equation in two-dimensional geometries.