The problem here, and the reason CAESAR II gives you an error, is that WRC-297 is intended for "cylinder-cylinder" intersections. A nozzle on a head is not a "cylinder-cylinder" intersection. So "technically", you can't do this using WRC-297.

The only procedure in CAESAR II with this capability is the PD-5500 nozzle. However, I would not suggest you use this unless you are familiar with the PD-5500 code (which is my recommendation regarding everything in CAESAR II).

If you really really really want (have) to use WRC-297 for this geometry, here are the steps necessary. Be warned however, this is an approximation and as such, your results will be approximate!.

• Define the vessel and nozzle diam/thck as usual.
• For the "distance to stiffeners" use the radius of the head. The sum of these two values should be the head diameter. If the nozzle is in the center of the head, both values will be equal.
• For the "vessel centerline cosines" specify values 90 deg to the nozzle. NOTE, this is not correct, but it is necessary to analyze this geometry.
• Document these assumptions in the Title Page of the CAESAR II input.

What does this do for you? As soon as you use the WRC-297 flexibilities, you are hoping to reduce the boundary condition stiffnesses by 6 orders of magnitude (from 1E12 to 1E6). The above assumptions are not 100% correct, the resulting stiffnesses may be off by a factor of 2 or 3. Caution is in order.