Retrofitting of attachments of the RA-piping system for fluid dynamic load cases after uprating
Assignment of tasks
Within the scope of a submitted uprating the RA-system has to be proven for the load cases:
- Turbine trip at 100% power (TUSA100 – level B)
- Turbine trip at partial load operation of a leg respectively (TUSA300 – level B)
- Opening of the discharge-lock valve S004 (AAV – level B)
- 0,1F-crack (level D)
- 2F-fracture (level D)
and an optimization and retrofitting of the attachments has to be carried out.
Problem
Due to the huge loads from the fluid dynamic load cases it wasn't able to prove the attachments – especially the power house fixed point (MH-FP) – and the structure of a building in traditional way. Extensive redevelopment measures up to the reinforcing of the structure of a building (fundaments, floors) would have been the consequence.
By the following measures the attachments and the structural attachments were reduced:
- Valve optimization in load case AAV,
- Integration of single attachments (e.g. MH-FP) in the piping calculation model,
- Transient analysis of the fluid loads and
- Choice of a weaker attachment concept

Results of the optimization
Elimination of attachments
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Reconstruction of attachments
New construction of attachments
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Summary
Software | Hardware |
Fluid dynamic calculations 11 Structural dynamic calculations 4 Single proofs 2 |
attachments altogether 189 removal 35 reconstruction 73 New construction 2 |