Zachry Nuclear Engineering
Mechanical Engineering & Design

Mechanical Engineering & Design

Zachry Nuclear has significant experience encompassing the full breadth of mechanical engineering needs, ranging from system, structure, component (SSC) design and installation support, assessing and providing solutions to operational challenges, system performance improvement and project management. We have developed Safety and Non-Safety Related evaluations which assess existing plant configurations against proposed changes. These evaluations are often the first step in determining the feasibility of a proposed plant modification and include assessments of multiple implementation options.

We have developed:
The following demonstrates the adaptive, flexible, and diverse capabilities possessed by our Mechanical Engineering Staff.
Commercial Grade Dedication Package Development
We have the capabilities, experience and expertise necessary to develop Commercial Grade Dedication (CGD) Packages and perform client reviews of vendor completed packages. Zachry Nuclear has performed CGD of services and software to be utilized in Safety Related applications at nuclear power generation facilities. We have also developed procedural guidance for CGD of services and software that follows the established industry guidance and involves the development of a CGD Plan, the selection of an appropriate dedication method and the completion of a CGD Report.
Equipment Abandonment
Zachry Nuclear supports our clients with system and component abandonment or removal from service projects. These projects include identification of interfacing systems, performing document and drawing updates, and preparing procedure markups. Typically the equipment is left in place but isolated such that it cannot be operated or affect the operation of other equipment or systems.
Failure Modes and Effects Analysis (FMEA)
We develop Failure Modes and Effects Analyses (FMEA) utilizing both the Zachry Nuclear Instruction and client procedures. The FMEAs are utilized to support design modifications and Engineering Evaluations. FMEAs include component by component assessments of failures and the impacts to system operation and performance. We have performed thousands of design change packages to modify plant SSCs for which FMEAs have been performed.
Heating, Ventilation and Air Conditioning (HVAC)
Our staff has extensive experience and expertise for solving HVAC problems, new system design, system modification, computer modeling and other analysis. Designs and modifications have included chilled water systems, cooling tower systems, steam and hot water systems, open and closed cooling water systems, compressed air systems, and liquid nitrogen systems. In addition, we have provided designs for filtration, smoke, and CO2 venting systems. Our HVAC subject matter experts (SMEs) are affiliated with various industry groups including NHUG, ASHRAE, ASME, AMCA, SMACNA and NFPA.
Ultimate Heat Sink Increased Temperature Limits
Zachry Nuclear has significant experience assisting customers with the impacts of increasing ultimate heat sink temperatures. For example, as a result of increasing sea temperatures, a nuclear site experienced operational challenges as the Ultimate Heat Sink (UHS) temperature approached the Technical Specification limit. Zachry Nuclear performed the required analysis to demonstrate that the plant could remain operable. In order to avert a similar challenge in future summer periods, We have performed engineering and analysis to support a Technical Specification change to raise the UHS temperature to provide additional margin to accommodate increasingly warmer summertime intake water temperatures.
Mechanical Calculations
Zachry Nuclear has extensive experience developing and revising calculations to support new or modified plant SSCs. Examples include building heat loads, hydrogen generation, heat exchanger sizing and performance, spent fuel pool heatup and decay heat removal, combustible load analysis, cavitation, net positive suction head, and piping thermal/hydraulic analysis. We prepare calculations in accordance with our own procedures or those of our clients.
Plant Modifications/Design Change Packages
Zachry Nuclear has designed plant modifications for the nuclear industry for over 40 years. These change packages vary widely in complexity, from minor piping changes to complex SSC modifications and new design installations, often involving multi-discipline project teams. We prepare modification packages in accordance with our own procedures or those of our clients, including the standard design process.
Power Plant Uprate Programs
Our experienced engineering personnel have been involved in supporting Power Uprate programs at various nuclear facilities. We have successfully supported several utilities in performing specific system analysis and providing a cost-effective alternative to identifying, scoping, and implementing the plant modifications to achieve higher power levels.
10CFR 50.59 Applicability Determinations, Screens, and Evaluations
Zachry Nuclear develops 10CFR 50.59 documentation (Applicability Determinations, Screens and Evaluations) to support plant design changes or stand-alone documents. Many of our engineers are qualified under our clients' programs such that additional client reviews and signatures are not required. We have prepared thousands of applicability determinations, screens, and evaluations in support of the design changes we prepare for our clients.
Buried/Underground Pipe Refurbishments and Replacements
Our subject matter experts in Buried/Underground Pipe Refurbishments and Replacements are experienced working with ISCO (High Density Polyethylene - HDPE) and Structural Technologies (Carbon Fiber Reinforced Polymer - CFRP) for degraded piping replacement/remediation.