Mathematical adjoint solution to the nodal code QUANDRY
Attempts have been made to use perturbation theory expressions from advanced nodal codes to obtain reactivity coefficients. The adjoint vectors used in these formulations are obtained by taking the transpose of the matrix associated with the regular nodal equations and finding its solution vector. Lawrence was able to solve for the vector exactly in two-dimensional problems, and to a very good approximation in three-dimensional DIF3D nodal models. Taiwo and Henry reported that the adjoint solution vector obtained and used in their analyses corresponds to the coarse mesh finite difference form of the QUANDRY equations. The mathematical adjoint solution to the actual QUANDRY adjoint equation was not available at that time and is reported here. Problems done to date have converged to the expected eigenvalue of unity, and adjoint fluxes in fueled and reflector regions indicate the expected trend of the two-group adjoint distribution. The adjoint solution obtained in this work can be used in many applications. Foremost of these is the evaluation of local reactivity coefficients. Furthermore, these vectors can be used to weight cross sections and parameters in transient analysis. They can also be used to evaluate Doppler weighting factors required for rod ejection analyses.
- OSTI ID:
- 6869387
- Report Number(s):
- CONF-8711195-
- Journal Information:
- Trans. Am. Nucl. Soc.; (United States), Journal Name: Trans. Am. Nucl. Soc.; (United States) Vol. 55; ISSN TANSA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
220100* -- Nuclear Reactor Technology-- Theory & Calculation
ALGORITHMS
COMPUTER CODES
MATHEMATICAL LOGIC
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
PERTURBATION THEORY
PHYSICS
POWER PLANTS
Q CODES
REACTIVITY
REACTOR PHYSICS
THERMAL POWER PLANTS
THREE-DIMENSIONAL CALCULATIONS