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Conference Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Deep Space: The new frontier of radiation controls
In commercial nuclear power, there has always been a deliberate tension between the regulator and the utility owner. The regulator fundamentally exists to protect the worker, and the utility, to make a profit. It is a win-win balance.
From the U.S. nuclear industry has emerged a brilliantly successful occupational nuclear safety record—largely the result of an ALARA (as low as reasonably achievable) process that has driven exposure rates down to what only a decade ago would have been considered unthinkable. In the U.S. nuclear industry, the system has accomplished an excellent, nearly seamless process that succeeds to the benefit of both employee and utility owner.
Andrew J. Hummel, Todd S. Palmer
Nuclear Science and Engineering | Volume 183 | Number 1 | May 2016 | Pages 149-159
Technical Note | doi.org/10.13182/NSE15-37
Articles are hosted by Taylor and Francis Online.
The most widely used and versatile medical radioisotope today is 99mTc. Roughly 30 million people depend on this radioisotope for diagnostic imaging procedures each year, and this demand is expected to grow. Although there are numerous ways of producing this isotope, the most common is from fission product 99Mo, which is produced in all nuclear reactors fueled with 235U as a fission fragment with a yield of around 6.1%. Molybdenum-99 has a half-life of just over 2.5 days, and it will decay to 99mTc 87% of the time. The Reduced Enrichment for Research Test Reactors program was established at Argonne National Laboratory in 1978 to investigate technology that would aid in converting highly enriched uranium (HEU) facilities to low-enriched uranium (LEU) fuel. Since the majority of all 99Mo produced currently comes from the irradiation of HEU fuel targets, there has been a growing effort to design LEU targets that can yield comparable quantities of high specific activity 99Mo. Recently, a novel LEU target design has been developed for use in TRIGA reactors for the production of 99Mo. The simulation tool MCNP5 was used to examine the neutronic behavior of multiple core configurations fueled solely with this new target.
