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Former Exelon CEO Chris Crane remembered for “transformational milestones”
Crane
Exelon announced that Chris Crane, the company’s former chief executive, passed away on Saturday in Chicago at the age of 65.
Crane served as the company’s president and CEO from 2012 until his retirement in December 2022. During his tenure, he steered the energy company through several transformational milestones, including the successful mergers with Constellation Energy in 2012 and Pepco Holdings in 2016, creating the largest utility business by customer count in the United States.
In 2022, with the spin-off of Constellation as the generation and retail side of energy business (with the largest U.S. nuclear fleet), Crane led the creation of a stand-alone transmission and delivery energy company.
C. D. Bowman, E. G. Bilpuch, D. C. Bowman, A. S. Crowell, C. R. Howell, K. McCabe, G. A. Smith, A. P. Tonchev, W. Tornow, V. Violet, R. B. Vogelaar, R. L. Walter, J. Yingling
Nuclear Science and Engineering | Volume 161 | Number 1 | January 2009 | Pages 68-77
Technical Paper | doi.org/10.13182/NSE161-68
Articles are hosted by Taylor and Francis Online.
The results of two experiments combined show that the diffusion length D for thermal neutrons in the graphite studied is 24% larger than expected from classical experiments and that the boron equivalent absorption is smaller than expected and consistent with zero. Taken together, the results indicate a reduction in parasitic thermal neutron absorption in heterogeneous graphite reactors by about 30%. The first experiment measured the z-dependence of thermal neutron flux in a column of 12 t of granular graphite with a neutron source at the bottom. A second measurement was made by pulsing the column with a neutron source at its center and measuring the neutron decay rate as a function of time after a pure exponential decay had been established. The diffusion coefficient D adjusted to a density of 1.60 g/cm3 is 1.05 ± 0.03 cm compared with the commonly accepted value of 0.85 ± 0.013 cm. The absorption in our graphite owing to impurities was found to be <10% of that from carbon alone. The parameter a/D that measures neutron loss was determined to be 0.000235 ± 0.000026 cm-2 for a density of 1.60 g/cm3 and may be compared with the commonly accepted value of 0.000340. The performance of graphite thermal spectrum reactors constructed using our graphite would be significantly enhanced over present expectations because neutron loss to graphite is a major factor in the neutron economy of graphite-moderated thermal reactors.