Undercurrent: The Alden Blog

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Industrial fluid dynamics insights


Venturi Design for a Circulating Dry Scrubber
One of Alden’s key business areas is designing, analyzing, and improving air pollution control equipment for fossil power plants.  Over the last decade, circulating dry scrubbers (CDS) have become a popular way to remove SO2 and other acids from the flue gas of coal-burning power plants.  A few of the benefits of CDS technology include a relatively low cost of installation, high removal efficiency, low water usage, and no wastewater that needs to be treated – in fact it can be a means to dispose of other wastewater from the plant. The technology works by injecting lime powder into a reaction vessel, and also spraying in a small amount of water (Figure 1).  The water coats the lime particles and eventually evaporates, which helps to improve acid removal.  The powder is suspended in the reaction vessel and mixed using a high velocity stream of flue gas entering from the bottom of the reactor.  Once mixed and reacted, the gas carries the solids out through the top of the reactor into a fabric filter, which acts like a vacuum bag to ...

Nuclear Procurement Issues Committee Annual Meeting
In June 2016, the Alden Quality Assurance department attended the annual NUPIC (Nuclear Procurement Issues Committee) vendor conference for the third year in a row.  NUPIC is an organization that provides a cost effective method for NRC (Nuclear Regulatory Commission) licensee's to maintain their approved suppliers lists by sharing audits of suppliers.  The vendor conference is an opportunity for utilities, suppliers and regulators to get together and discuss current issues which impact the processes of purchasing and supply of nuclear components and services.  This annual event has been beneficial for Alden QA to stay abreast with current nuclear quality issues and to maintain a high quality product for our clients. The NUPIC vendor conference is hosted each year by a different utility and in addition, the NRC sends representatives and holds a workshop on vendor oversight at the conference every two years.  The 2016 event was hosted by Ameren in St. Louis, Missouri at a hotel adjacent to the Jefferson National Expansion Memorial (U.S. National Park featuring the Gateway Arch and Old Courthouse, see photos).  Conference topics included an ...

The Future of Nuclear Power
As the US Nuclear fleet continues to age, and the availability of alternate sources of energy continues to rise, it is not surprising that we are seeing more news of permanent plant closures.  The most recent announcements come from Entergy, stating they will shut down Palisades permanently on October 1st, 2018, and Indian Point in 2021. For many of these plants announcing closures, the writing has been on the wall.  In 2013, economist Mark Cooper, a Senior Fellow for Economic Analysis at the Institute for Energy and the Environment at Vermont Law School published Renaissance In Reverse, an interesting read on the factors that affect the viability of nuclear power economically.  He provided a list of plants that face particularly significant challenges to operation, which is provided below. Palisades (Repair impending, local opposition) Ft. Calhoun (Outage, poor performance) Nine Mile Point (Site size saves it, existing contract) ...