Although Roeslein & Associates, Inc. is a household name in the canmaking industry, it is less known within the markets to which it is new: pharmaceutical, oil and gas, refinery, power, chemical and petrochemical. Roeslein is earning a reputation for reduced start-up times and improved efficiencies using its signature approach, Modularization, Unitization and Preassembly. One example of this type of success is Roeslein’s development of an automated sump pump system for an East Coast nuclear facility in 2012.
Roeslein’s engineers designed a series of sump pumps on skids for 12 safety-related electrical manholes within the nuclear facility to ensure that safety-related cables remain dry. The automatic pumping system removes groundwater from below grade cable vaults and sends it to the facility’s on-site industrial waste sump system for testing and proper disposal. Before the Roeslein system was installed, the nuclear facility had been manually inspecting and pumping water out of 41 vaults to comply with a U.S. Nuclear Regulatory Commission (NRC) information notice about preventing safety-related electrical cables housed in underground cable vaults from continual water submergence.
The NRC issued the information more than two years ago after finding that cables not qualified to be continually submerged in water can degrade, increasing the probability that they will fail. Prior to the design and installation of the Roeslein automatic pump system, an inspection of this East Coast facility revealed power cables in one of its 41 underground vaults were submerged in 2.5 feet of standing water.
John DeMoulin, Roeslein’s director of Business Development and Marketing, said, “We were called in to provide a system to prevent cable failure but also were asked to eliminate extensive life cycle cost. Roeslein’s reputation for delivering quality engineering and preassembled modular products on short timelines was key to being chosen for the project.”
The sump skids were fabricated and tested at Roeslein’s modular fabrication facility in Red Bud, Illinois. The design uses existing sump piping through which a bubbler sensor reads water levels inside the vault sump area. Since each manhole could service up to six vaults, a programmable logic controller (PLC) directs the pumping sequence with the discharged water flowing into a newly installed common drain line that terminates at the existing HNP turbine building industrial waste sump. The sump skids are connected with fiber optic and power cables and controlled by a PLC. The fully automated system allows two pumps to be operating at the same time if necessary.
Roeslein’s Senior Project Manager Brian Hanger said, “Roeslein applied experience gained by working on a number of similar projects. One of the clients’s key goals was to have the systems fully functional and tested while at our fab shop so they could simply set them in place with minimal field work once they were at the nuclear facility.”
The project was not without challenges. Engineers had to design a system made of components capable of pumping water to the existing treatment facility from the 14-foot deep underground vaults where safety-related cables were located without putting equipment inside the vaults. Testing at fabrication facilities demonstrated the pump used was easily able to pump water a vertical distance of 20 feet.
The system – which has been operational since December of 2012– allows one pump to handle all vaults at a particular manhole. The design therefore called for 12 pump skids to handle 41 vaults. All pump skids are continuously monitored by the PLC control system. When a vault reaches a high water level, the PLC will allow the water to be pumped using a register to queue the request in the event the system detects a high water level at other vault locations.
Roeslein & Associates looks forward to putting its expertise assembling and testing modularized systems within the controlled environment of its facilities for additional projects within the nuclear power industry.