History of NAS

Zachry was contracted with Westinghouse Electric International to build the José Cabrera Nuclear Power Station for Union Electrica Madrileña, S.A. (now part of Naturgy Energy Group S.A.). Also known as Zorita, this was the first nuclear power plant in Spain. It was a 160 MW PWR built on the bank of the Tajo river between the Bolarque and Zorita dams. Construction began in 1965 and was completed in only 33 months. Zorita operated for 38 years before being shutdown in 2006.

The Proto-Power Management Corporation was founded in 1974 by seven individuals from General Dynamics' Electric Boat Division. The company's initial focus was in providing project management, quality assurance, and third party consulting services to the commercial nuclear power industry.

In 1994, Proto-Power completed the development, testing, and release of its nuclear system analysis software, PROTO-FLO Since then, the Analysis group has continued to improve and add to the PROTO-Series of software tools for plant analysis with PROTO-HX for heat exchanger performance and PROTO-HVAC for heating, ventilating and air conditioning systems performance. By 1997, Proto-Power had outgrown its office facility and moved to its current office location.

In 2000, Proto-Power was acquired by Xcel Energy, a utility based in Minneapolis. By this time, the company had grown to about 125 employees and was focused on our current core business of providing engineering, design, and project management services to support the US nuclear power industry.



In 2005, Xcel Energy sold Proto-Power to Zachry Group, a privately held construction firm based in San Antonio, TX. The company was renamed Zachry Nuclear Engineering in 2009, following Zachry's decision to establish a separate new business entity, Zachry Nuclear Inc., to provide services to the existing US fleet of nuclear units and to pursue new nuclear power plant construction projects.

In 2010, ZNE opened a new office in Charlotte, NC to better focus on nuclear utilities located on the southeastern region of the US. The office was co-located with a ZEC office.

The ZNE Analysis Division was formed in 2011 with the acquisition of Numerical Applications, Inc. (NAI). Established in 1984, NAI was an industry leader in the development, support and application of software for multiphase flow and heat transfer. NAI's GOTHIC code is used for containment and primary system analysis, building performance (e.g., room heat up, hazardous gas distribution, and fission product release) and to model component systems to address specific operating and safety concerns. The software is used in the US and internationally for safety and licensing analysis for Generation 2, 3 and 4 reactor designs, including liquid sodium and molten salt systems.

In 2015, the ZNE Analysis Division range of capabilities and expertise was further advanced by the acquisition of Computer Simulation and Analysis, CSA. Founded in 1988, CSA brought a team of nuclear engineers and computer scientists with extensive expertise in the simulation of reactor core and system thermal hydraulics. Their VIPRE and RETRAN codes are widely used to support existing plants and new system designs for operating and safety analysis. The company was recognized by the US Small Business Administration with a Tibbetts award for innovative and technical accomplishments in the Small Business Innovation Research Program.

In 2022, the ZNE Analysis Division was rebranded as Numerical Advisory Solutions (NAS).