ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Explore membership for yourself or for your organization.
Conference Spotlight
2026 Nuclear Energy Conference & Expo (NECX)
August 24–27, 2026
Dallas, TX|Hilton Anatole
Latest Magazine Issues
Jul 2026
Jan 2026
2026
Latest Journal Issues
Nuclear Science and Engineering
August 2026
Nuclear Technology
July 2026
Fusion Science and Technology
Latest News
The deadline arrives: Checking in on the Reactor Pilot Program
On May 23, 2025, President Trump signed Executive Order 14301, “Reforming Nuclear Reactor Testing at the DOE,” which instructed the Department of Energy to create a Reactor Pilot Program (RPP)—a new system in which companies could pursue DOE authorization to build and test their first-of-a-kind nuclear technologies. EO 14301 set an ambitious goal for that program: three reactors achieving criticality by July 4, 2026.
Chia-Jung Hsu
Nuclear Science and Engineering | Volume 47 | Number 3 | March 1972 | Pages 380-388
Technical Note | doi.org/10.13182/NSE72-A22426
Articles are hosted by Taylor and Francis Online.
The heat transfer characteristics of a rod which is dislocated from its symmetrical position are studied analytically for slug flow through tightly packed rod bundles (P/D ratio down to ≈1.00). Explicit equations describing the temperature fields in the fuel core, the cladding, and the elemental coolant flow area are obtained by assuming uniform fuel power density. Variation of the rod-average Nusselt number, as well as the heat flux distribution at the outer wall of the cladding, is examined for selected values of σ, the P/D ratio, the cladding thickness parameter, λ(=r1/r2) and the thermal conductivity ratios, κ and κw. The present solutions, when specialized to the case of σ = 0.0 (i.e., no rod displacement) show excellent agreement with the results reported by Axford and by Dwyer and Berry who studied the corresponding three-region and two-region problems, respectively, for symmetrical rod bundles with no rod displacement.