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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
Meeting Spotlight
Conference on Nuclear Training and Education: A Biennial International Forum (CONTE 2025)
February 3–6, 2025
Amelia Island, FL|Omni Amelia Island Resort
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!
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Reboot: Nuclear needs a success . . . anywhere
The media have gleefully resurrected the language of a past nuclear renaissance. Beyond the hype and PR, many people in the nuclear community are taking a more measured view of conditions that could lead to new construction: data center demand, the proliferation of new reactor designs and start-ups, and the sudden ascendance of nuclear energy as the power source everyone wants—or wants to talk about.
Once built, large nuclear reactors can provide clean power for at least 80 years—outlasting 10 to 20 presidential administrations. Smaller reactors can provide heat and power outputs tailored to an end user’s needs. With all the new attention, are we any closer to getting past persistent supply chain and workforce issues and building these new plants? And what will the election of Donald Trump to a second term as president mean for nuclear?
As usual, there are more questions than answers, and most come down to money. Several developers are engaging with the Nuclear Regulatory Commission or have already applied for a license, certification, or permit. But designs without paying customers won’t get built. So where are the customers, and what will it take for them to commit?
John M. Jamieson, Geoffrey G. Eichholz
Nuclear Technology | Volume 39 | Number 1 | June 1978 | Pages 95-100
Nuclear Safety Analysis | Energy Modeling and Forecasting / Analysis | doi.org/10.13182/NT78-A17011
Articles are hosted by Taylor and Francis Online.
A method for analyzing nuclear material for different fissile nuclides by cyclic activation has been developed and tested experimentally with samples of 235U and 239Pu, singly and in combination. The method of analysis is based on the differences in the abundances and half-lives of delayed neutron groups between the various fissile nuclides. The steady-state delayed neutron response to periodic activation is independent of activation cycle period at short periods, decreases exponentially with period at long periods, and has a break point, or knee, where the response changes from constant to exponential, or from one exponential to another, with greater slope for each characteristic emitter present. The activation cycle periods at which these break points occur, the slopes of the exponential fall-off or response with cycle period between break points, and the absolute magnitude of the response at any cycle period are all functions of the effective half-lives and abundances of the delayed neutron precursors activated, so, consequently, the characteristic delayed neutron response as a function of activation cycle period is different for the various fissile species. In the experiment, cyclic activation was accomplished by moving the samples containing fissile material cyclically through a thermal-neutron beam from the Georgia Tech Research Reactor, out of the beam and through a delayed neutron detector, and back through the beam, etc. The delayed neutron response was recorded at activation cycle periods ranging from 0.1 to 100 s for samples containing varying amounts of 235U and 239Pu. Deviations in the responses of the samples containing both 235U and 239Pu from the response of standards containing only 235U or 239Pu were determined to infer the 235U- to-239Pu ratio. After the ratio of the two fissile nuclides present was obtained, the delayed neutron response at short cycle periods was used to estimate the mass of each fissile nuclide present in the sample. For samples containing about a gram of fissile material, accuracies on the order of 2% for 235U and 4% for 239Pu could be obtained for 1.5-h experiment run times when the fissile nuclides were present in about equal portions. Accuracies were dependent on the 235U-to-239Pu ratio and on the total mass of fissile materials present.
