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Fusion Science and Technology
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Getting back to yes: A local perspective on decommissioning, restart, and responsibility
For 45 years, Duane Arnold Energy Center operated in Linn County, Ia., near the town of Palo and just northwest of Cedar Rapids. The facility, owned by NextEra Energy, was the only nuclear power plant in the state.
In August 2020, a historic derecho swept across eastern Iowa with winds approaching 140 miles per hour. Damage to the plant’s cooling towers accelerated a shutdown that had already been planned, and the facility entered decommissioning soon after, with its fuel removed in October of that year. Iowa’s only nuclear plant had gone off line.
Today the national energy landscape looks very different than it did just six short years ago. Electricity demand is rising rapidly as data centers, artificial intelligence infrastructure, advanced manufacturing, and electrification expand across the country. Reliable, carbon-free baseload power has become increasingly valuable. In that context, Linn County has approved the rezoning necessary to support the recommissioning and restart of Duane Arnold and is actively supporting NextEra’s efforts to secure the remaining state and federal approvals.
Jason Wilson, James Becnel, David Demange, Bernice Rogers
Fusion Science and Technology | Volume 75 | Number 8 | November 2019 | Pages 802-809
Technical Paper | doi.org/10.1080/15361055.2019.1629249
Articles are hosted by Taylor and Francis Online.
The tokamak exhaust processing (TEP) system performs chemical separations on ITER fuel cycle process streams. TEP recovers hydrogen isotopes (Q2) from impurities such as argon, nitrogen, tritiated water (Q2O), tritiated ammonia (NQ3), and tritiated hydrocarbons such as methane (CQ4). TEP sends the hydrogen isotopes for subsequent processing to the isotope separation system or the storage and delivery system. At the same time, an impurity gas stream of extremely low tritium content (less than 8.88 TBq of tritium per day) is produced and sent to the detritiation system (DS). To accomplish the separation, the major hydrogen processing subsystems within TEP are hydrogen-like processing (HLP) and air-like processing/water-like processing (ALP/WLP). (Hydrogen-like gases are Q2, He, and Ne; air-like gases are Ar, O2, N2, O2, and CQ4; and water-like gases are Q2O and NQ3). The main processing equipment used for the HLP is a series of palladium-silver permeators (PMs) with ALP/WLP using a series of Palladium Membrane Reactors (PMRs). Aspen Dynamics is the primary tool for verifying system performance of the TEP design. Aspen Dynamics is a commercial, equation-based simulation package for chemical processing. The software enables the user to develop a process model from predefined unit-operation models or construct its own unique unit-operations model. Verification of the TEP simulation model to experimental data was achieved during the TEP conceptual design. The designs for the TEP HLP and ALP/WLP subsystems are examined for the updated gas inputs in terms of compositions and flow rates. The TEP simulation is used to predict tritium output of the TEP processing subsystems This paper describes how the Aspen model of the equipment was improved and used to size the equipment (PMs and PMRs) to process the various gas streams and maintain the discharge to DS to below the limit.
