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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.
Zeyun Wu, Robert E. Williams, J. Michael Rowe, Thomas H. Newton, Sean O’Kelly
Nuclear Technology | Volume 199 | Number 1 | July 2017 | Pages 67-82
Technical Paper | doi.org/10.1080/00295450.2017.1335146
Articles are hosted by Taylor and Francis Online.
This paper presents preliminary neutronics and thermal hydraulics safety analysis results for a low-enriched uranium (LEU) fueled research reactor concept being studied at the National Institute of Standards and Technology (NIST). The main goal of this research reactor is to provide advanced sources for neutron scattering experiments with a particular emphasis given to high intensity cold neutron sources (CNSs). A tank-in-pool type reactor with an innovative horizontally split compact core was developed in order to maximize the yield of the thermal flux trap in the reflector area. The reactor concept considered a 20 MW thermal power and a 30-day operating cycle. For non-proliferation purposes, a LEU fuel (U3Si2-Al) with 19.75 wt% enrichment was used. The core performance characteristics of an equilibrium cycle with several representative burnup states—including startup and end of cycle—were obtained using the Monte Carlo–based code MCNP6. The estimated maximum perturbed thermal flux of the core is ~5.0 × 1014 n/cm2-s. The calculated brightness of the CNS demonstrates an average gain factor of ~4 compared to the current source operated at the existing NIST reactor. Sufficient reactivity control worth and shutdown margins were provided by hafnium control elements. Reactivity coefficients were evaluated to ensure negative feedback. Thermal hydraulics safety studies of the reactor were performed using the multi-channel safety analysis code PARET. Steady-state analysis shows that the peak cladding temperature and minimum critical heat flux ratio are less than design limits with sufficient safety margins. Detailed transient analyses for a couple of hypothetical design-basis accidents show that no fuel damage or cladding failure would occur with the protection of reactor scrams. All these study results suggest this new research reactor concept offers a demonstrable potential to greatly expand the cold neutron capability with a 20 MW power and certified LEU fuels.
