Development and Validation of a Three-Dimensional Diffusion Code Based on a High Order Nodal Expansion Method for Hexagonal- Geometry

Table 4

Numerical results of three-dimensional VVER 440 benchmark.

Code	Number of axial planes	Eigenvalue	error (pcm)	(%)	CPU time (sec)
DIF	—	1.01132	—	—	—
HNHEX	12	1.01243	111	−8.6	5.16
HNHEX	12	1.01186	54	−3.72	6.12
HNHEX	24	1.01161	29	−3.32	12.3
ACNECH	12	1.01054	−78	−4.9	16
AFEN	12	1.01162	30	3.2	592.8
ANC-H	12	1.01157	25	1.28	124.8

Reference.
Applying flat approximation for partially integrated axial leakage and quadratic approximation for one-dimensional axial spatially flux.
Applying quadratic approximation for partially integrated axial leakage and four-order approximation for one-dimensional axial spatially flux.