Alternative calculations

The verification of some kind of calculations or design analysis can be per­formed, comparing the original results to those obtained through other methodologies of analysis or calculation.

When alternative calculations are used to verify original calculations, reviews should be performed to confirm the adequacy of assumptions, the input data, the computer code and any other method of calculation used.

The alternative method used may be simpler or less rigorous than the original one. However, all safety-significant differences must be assessed and justified.

Qualification tests

A test programme performed on a model or prototype may be used as a design verification tool if it is performed under the most adverse design conditions for the specific design features being verified. When criteria cannot be satisfied, testing may be acceptable if the results can be extrapo­lated to the most adverse conditions.

Qualification testing should be performed at qualified testing facilities and in accordance with approved procedures defining the reference require­ments, the test configuration and the acceptance criteria.