Advantages of having independent capabilities for nuclear calculations

Iberdrola has been working during the last couple of years to reach the capability for being able to introduce new fuel designs coming from a vendor different than the actual one. Cofrentes is the plant for which this philosophy applies. For dealing with different fuel supplies is very convenient to have an independent analyses capability in order to make technical decisions. Iberdrola is using the following code package. Tables-3 (cell constants tabulation), Simulate-3 (Core simulator), Slick (linking code for core kinetics), Retran-03 (Transient code) and Frosstey (Thermal and Mechanical fuel behavior) to do its own analyses. Many benefits may be obtained if the utility that operates the plant is also who license the reloads and safety analyses, it always contributes to a better knowledge of the plant and of course provides economical benefits. In spite of the licensing process has not finished yet, we have already verified that an independent calculation capability provides many advantages, this article show some of them. (Author)