SEISMIC ANALYSIS & QUALIFICATION OF EDG SET ALONG WITH AUXILIARIES INCLUDING PIPING
Nuclear seismic qualification is a highly specialized field in which ProSIM has gained significant expertise with over 20 years of experience. One of the most critical projects which ProSIM has executed is the FEA seismic qualification of emergency DG set and its auxiliary equipment for KAPP 3&4, RAPP 7&8.
This EDG System is more complex because it involves significant number of components:
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- Rotary Component (Crank Shaft)
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- Reciprocating Component (Piston)
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- Electrical component (Alternator)
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- Control & Instrumentation (Panel & Thermowell)
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- Passive Components (Pressure Vessels, Strainers, Heat Exchangers)
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- Active Components like (Pumps, Compressors etc)
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- Exhaust Piping & Interconnected Piping
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- Lattice structure
- Foundation Design
This is a critical equipment which supplies required backup power to the core cooling systems during emergency/loss of regular power supply. Incase of failure of EDG set during a seismic event, the reactor meltdown occurs due to over-heating and thus exposure of radiation to environment.
The requirement for the seismic qualification included evaluating the 4.2MW capacity EDG set and auxiliaries:
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- Fuel Oil System.
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- Lubricating Oil System.
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- Jacket Water System.
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- Compressed Air System.
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- Intake Air System.
- Exhaust system.
The main challenge faced by the customer was that all the auxiliary equipment had already been manufactured and supplied to the power plant site. However, the site did not accept the materials as the seismic analysis certification was not available during supply, and it had become a bottleneck for the client. Due to this critical time sensitive issue, the customer approached ProSIM due to its credibility as being a renound seismic design consultant for urgent seismic qualification for operating loads along with the combination of seismic loads i.e. OBE & SSE at their respective service levels as per ASME Sec III Div 1 ND & NF.
During the seismic analysis, it was observed that certain auxiliaries were not meeting the code requirement i.e., the stress generated had exceeded the allowable limits. ProSIM reworked the analysis by providing the critical engineering solution swiftly by providing additional stiffeners and load bearing members without significant change in the original design.
As a result of ProSIM’s swift seismic analysis by addressing the customer pain point, the project was successfully completed in 6 months, and the customer got the necessary clearances for installation by the end user (NPCIL).
Based on ProSIM’s swift Nuclear Seismic Qualification, the bottlenecks were relieved making the customer happy. The customer has since become a regular client, and collaborating with us for NPCIL works.
