Nuclear Science and Engineering -- ANS / Publications / Journals / Nuclear Science and Engineering

About ANS
- ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
About Nuclear
- Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Communities
- Division Spotlight
  Aerospace Nuclear Science & Technology
  Organized to promote the advancement of knowledge in the use of nuclear science and technologies in the aerospace application. Specialized nuclear-based technologies and applications are needed to advance the state-of-the-art in aerospace design, engineering and operations to explore planetary bodies in our solar system and beyond, plus enhance the safety of air travel, especially high speed air travel. Areas of interest will include but are not limited to the creation of nuclear-based power and propulsion systems, multifunctional materials to protect humans and electronic components from atmospheric, space, and nuclear power system radiation, human factor strategies for the safety and reliable operation of nuclear power and propulsion plants by non-specialized personnel and more.
Events
- Meeting Spotlight
  Nuclear Energy Conference & Expo (NECX)
  September 8–11, 2025
  Atlanta, GA|Atlanta Marriott Marquis
Standards
- Standards Program
  The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
Publications
- Latest Magazine Issues
  Jun 2025
  Jan 2025
  Latest Journal Issues
  Nuclear Science and Engineering
  August 2025
  Nuclear Technology
  July 2025
  Fusion Science and Technology
  July 2025
- Latest News
  NRC’s David Wright visits the Hill and more NRC news
  Wright
  The Nuclear Regulatory Commission is in the spotlight today for three very different reasons. First, NRC Chair David Wright was on Capitol Hill yesterday for his renomination hearing in front of the Senate’s Environment and Public Works Committee. Second, the NRC released its updated milestone schedules according to the Nuclear Energy Innovation and Modernization Act (NEIMA) and the executive orders signed by President Trump last month; and third, as reported by Reuters on Tuesday, 28 former NRC officials have condemned the dismissal of Commissioner Hanson earlier this month.
  Renomination: EPW Committee chair Sen. Shelley Moore Capito (R., W.Va.) opened the hearing with a statement praising Wright’s experience and emphasized the urgency of stable leadership at the NRC.
  “China is executing a rapid build-out of its nuclear industry,” Capito said. “The demand for clean, baseload power is skyrocketing as we position America to win the AI race.”
Search

Accurate solutions of the reactor kinetics equations in a lumped model with time-varying reactivity have been obtained using a spreadsheet on a personal computer (PC)/workstation from a straightforward power series recurrence relation. These have been shown to converge readily over time steps of ∼ s in models of a thermal reactor. Solutions over such macrosteps can readily be extended to durations of interest (∼100 s). Examples are given for both a ramp reactivity input and an oscillating reactivity. This latter shows in a direct fashion the first-order phase distortion and the second-order effect on power level that are generally associated with perturbation solutions that have to be taken to second order. The method applies also to fast reactors. It is concluded that accurate calculations of thermal and fast reactor transients, obtained analytically with considerable difficulty, are readily available to the student on a PC.