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Engineering & Design Services

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Reconfiguration of HV Substation

Altran Solutions developed studies, conceptual single line diagrams, magnitude cost estimates, and other documents that demonstrate how to make an existing substation configuration more secure, such that if a fault occurs on one 345 KV transmission line and a misoperation occurs on a second 345 KV transmission line, an outlet for a major generation station to the 345 KV grid will be maintained.

The scope of the study will be to evaluate configurations that may provide more secure operation of for various contingency conditions as well as alternative offsite power configurations that may improve plant operations and/or availability. Potential impacts of modifications on the substation and interfacing substations and review of potential equipment conflicts will be evaluated as well.

The goal will be to develop an electrical configuration that facilitates continued, uninterrupted operation in the unlikely event that any of the following occur:

• 345 KV transmission line fault
• 345 KV bus fault
• 345 KV transmission line fault with a stuck 345 KV circuit breaker
• 345 KV transmission line fault with one 345 KV circuit breaker out of service for maintenance
• 345 KV transmission line fault with the inadvertent trip out of an adjacent 345 KV transmission line

The study will also evaluate a design for a second substation in the area to reduce the outage requirements for this reconfiguration. Alternatives such as utilizing an SF6 insulated 345kV bus will be evaluated. Finally, the study will provide a quantitative analysis of the relative reliability of one configuration versus the other and provide a ranking for each alternative configuration evaluated.

Completion of Study Evaluation Off-Site Power Supplies and Grid Connections

Altran Solutions is currently finishing a detailed study to look at way to possibly upgrade the existing Grid Connections and Offsite Power Supplies for two large Nuclear Plants in the Northeast and their connection to the Regional ISO. The study included a Single Failure Analysis, Multiple Failure Analysis, Short Circuit, Load Flow and Protective relay considerations. Options evaluated including relocating tie points, addition of bus sections and construction of a complete new substation. The report will be used by both the Generator and the Transmission utility in their capital planning process.

AR/CR Resolution

Altran Solutions maintained an on-site team averaging 6 individuals to support a Nuclear Power Plant in the resolution and disposition of Electrical and I&C action requests (ARs) and condition requests (CRs). These items ranged from simple drawings discrepancies that need to be field walked and as-built to detailed safety related set point calculations which included going back to the original Tech Spec commitment, performing safety analysis, updating calculations and taking the AR/CR through the complete formal review process. Also included as part of this effort was the incorporation of all Design Modification Change Paper issued during the previous few outages into the affected Design Baseline Documents including drawings, Procedures and Calculations.