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.
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
2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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!
Latest Magazine Issues
May 2024
Jan 2024
Latest Journal Issues
Nuclear Science and Engineering
June 2024
Nuclear Technology
Fusion Science and Technology
Latest News
Securing the advanced reactor fleet
Physical protection accounts for a significant portion of a nuclear power plant’s operational costs. As the U.S. moves toward smaller and safer advanced reactors, similar protection strategies could prove cost prohibitive. For tomorrow’s small modular reactors and microreactors, security costs must remain appropriate to the size of the reactor for economical operation.
A. Fessler, A. J. M. Plompen, D. L. Smith, J. W. Meadows, Y. Ikeda
Nuclear Science and Engineering | Volume 134 | Number 2 | February 2000 | Pages 171-200
Technical Paper | doi.org/10.13182/NSE99-14
Articles are hosted by Taylor and Francis Online.
Cross sections have been measured with the activation technique at various neutron energies in the range of 16.0 to 20.5 MeV for the following 22 reactions: 19F(n,p)19O, 23Na(n,p)23Ne, 23Na(n,)20F, 25Mg(n,p)25Na, 27Al(n,p)27Mg, 28Si(n,p)28Al, 29Si(n,p)29Al, 29Si(n, np + pn + d)28Al, 31P(n,)28Al, 35Cl(n,2n)34mCl, 37Cl(n,p)37S, 46Ti(n,p)46mSc, 50Ti(n,p)50g+mSc, 51V(n,p)51Ti, 55Mn(n,)52V, 56Fe(n,p)56Mn, 57Fe(n, np + pn + d)56Mn, 57Fe(n,p)57Mn, 93Nb(n,)90mY, 93Nb(n,2n)92mNb, 119Sn(n,p)119gIn, and 138Ba(n,2n)137mBa. The half-lives for the reaction products range from 11 s to 10.15 days. Quasi-monoenergetic neutrons were produced via the 3H(d, n)4He reaction. In some cases isotopically enriched materials were used to enhance the reaction yield or to facilitate correction for interfering reactions leading to the same product. The gamma rays emitted from the irradiated samples were measured with a high-purity germanium detector. A pneumatic sample transport system was used to limit the decay of the radioactive products between neutron irradiation and gamma-ray counting. All cross sections were obtained as ratios to the standard reaction 27Al(n,)24Na, using as secondary neutron fluence references the 27Al(n,p)27Mg reaction as well as a calibrated Bonner sphere. Corrections have been applied for sample-irradiation and counting environment geometric effects, neutron absorption and multiple scattering, time variation of neutron-source strength, neutron-source angular distributions, secondary neutrons from the target, gamma-ray absorption, and gamma-ray sum coincidences. A detailed analysis of the uncertainty sources was performed. The present results are compared with other measurements and evaluated data. For seven reactions, measured cross sections have been obtained for the first time beyond 15 MeV. These new data help appreciably to resolve discrepancies in evaluated data files.