NRC Approved Method to Combine Seismic Spectrum with Static

[m_ridzon]

Folks, I'm curious what the latest NRC-approved method would be to combine static results + seismic results. So far, all I found was ML13260A310 from the NRC. For context, my question pertains to ASME Sec. III design. My customers typically feed me a seismic spectrum, along with all of the other normal service loadings. Therefore, I'll run my FEA model with the normal static loadings. I'll separately run my FEA model with the seismic spectrum. For the spectrum analysis, my ANSYS FEA uses the SRSS mode combination method in its algorithm (aka: Goodman-Rosenblueth-Newmark method). This means the spectrum results are sign-less (i.e., absolute value). So what I've done so far is take Static + Spectrum and Static - Spectrum combinations in post-processing. I'll do the combinations at the component level (i.e., Sx, Sy, Sz, Sxy, Syz, Szx) to comply with ASME Sec. III. I'll later extract derived stresses from the combined components (e.g., stress intensity, linearization, von Mises, etc.) to perform my ASME code checks.

My main questions are...
[ul]
[li]Is it acceptable to do...
Static + Spectrum
and
Static - Spectrum?[/li]
[li]Does the NRC have any newer guidance related to this?[/li]
[/ul]

 

[m_ridzon]

Bump.

 

[GD2]

OP,
I am not an expert in Seismic Design of SSC for Nuclear Facilities under NRC.
I believe NRC directs to use ASCE/SEI 4-2016 and ASCE/SEI 43-2019 for Seismic Analysis and Design of SSCs.

I am not sure how ANSYS fits in Seismic Design of ASME Sec III Code which has stringer requirements.

GDD
Canada