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Hopper Engineering Associates has been active in the power industry since the company's inception in 1979. Our clientele includes nuclear and non-nuclear utilities as well as equipment manufacturers. The company offers a diverse project history and team of experienced engineers.

Power Industry In Depth:

Hopper Engineering Associates provides multidisciplinary civil, structural and mechanical engineering support to utilities and manufacturers. In addition to supporting facility upkeep, we provide immediate engineering support as required during unexpected outages. We have extensive experience with nuclear safety related, security safeguards and non-nuclear safety related projects. We perform nuclear safety related projects under an in-house nuclear QA program based on 10CFR50 Appendix B and NQA-1.

The following project examples summarize our experience, however, are in no way comprehensive of our expertise. Please direct specific questions regarding project experience to Alex Reizman, Principal.

Featured Projects:

Vibrations in a plant main steam line caused repeat support failures. HEA identified the vibration source and designed visco dampers to mitigate the vibrations.

Crack indications were found at thermal joints of a containment polar crane rail. An ASME Section XI Code based fracture mechanics life evaluation for various crack orientations was performed using stresses found by finite element analysis.

HEA evaluated the structural integrity of the Dry Shielded Canister (DSC) and internals when subjected to an accident-scenario side-drop. Non-linear effects such as material plasticity, contact, and time-history loading were considered.

HEA determined the seismic displacement of a suspended crane hook load as part of an ISFSI project. Impact of a hook load into the structure was a primary concern. HEA used a computer model to accurately represent the crane, surrounding superstructure, and ground support structure including several nonlinear effects. Time histories were applied to the model to simulate design seismic events.

The actual number of loss of letdown thermal transients was found to exceed the design number of transients for a charging nozzle. HEA performed a Class I evaluation of the charging nozzle using thermal transient heat flow and stress analyses.

A Motor Operated Valve was replaced with a heavier valve, requiring reanalysis of the Pressurizer Valve Piping.

HEA performed a Class 1 piping analysis considering dynamic fluid transient loading and thermal stratification effects.

HEA performed a dynamic non-linear time history earthquake analysis of a turbine building structure, exhaust piping, and pipe support gaps. From the global model, we extracted time history column end forces and moments for overstressed members and used the data to perform detailed elastic buckling analyses for these members.

In-house inspection of a service water pipe elbow revealed thinning of the pipe walls due to erosion and/or corrosion. HEA mapped measurements taken of the wall thinning onto a detailed finite element model of the elbow. Analysis of this model indicated that stresses did not exceed allowable limits for short-term operation, enabling the client to postpone the replacement until the next scheduled outage.

Additional Spotlight Projects:

Below you will find additional Power related projects we have worked on.