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Standard Practice for Determining Equivalent Boron Contents of Nuclear Materials
NORMA vydaná dňa 1.10.2021
Označenie normy: ASTM C1233-15(2021)
Dátum vydania normy: 1.10.2021
Kód tovaru: NS-1040598
Počet strán: 3
Približná hmotnosť: 9 g (0.02 libier)
Krajina: Americká technická norma
Kategória: Technické normy ASTM
This practice details the recommended method for calculating the equivalent boron content (EBC) values of nuclear elements and materials that are of potential significance as thermal neutron poisons. EBC factors are determined from the atomic weight of elements and the thermal neutron absorption cross section in barns. These may be used depending upon the actual neutron energy characteristics of the applicable reactor system. The elements aluminum, fluorine, rubidium, barium, lead, silicon, beryllium, neon, tin, bismuth, oxygen, zirconium, carbon, magnesium, cerium, and phosphorus are not required to be included in the EBC calculations as their contribution to the total poison effect is not considerably significant.
Keywords:
boron, neutron absorption, nuclear materials, nuclear poisons ,, ICS Number Code 27.120.30 (Fissile materials and nuclear fuel technology)
Significance and Use | ||||||||||
4.1?Use of this standard practice yields an equivalent boron content (EBC) that can be used to characterize the neutron-absorbing properties of a nuclear material. The elements included in the calculation are typically chosen so that the EBC represents either the entire material (for example, for a moderator) or the impurities in the material (for example, for a nuclear fuel). This practice is typically used for materials in which thermal neutron absorption is undesirable. The EBC is not intended for use as an input to any neutronic calculation. The EBC factors in Table 1 were selected to represent neutron absorption in water reactors under normal operating conditions. It is the responsibility of the user to evaluate their suitability for other purposes. 1.1?This
standard details a recommended practice for the calculation of the
Equivalent Boron Content (EBC) for nuclear materials. The EBC is
used to provide a measure of the macroscopic neutron absorption
cross section of a nuclear material. EBC factors for the natural
elements are determined from their atomic masses and thermal
neutron absorption cross sections. This practice is illustrated by
using EBC factors that are based on thermal neutron (2200 m/s)
absorption cross sections. Other EBC factors may be used depending
upon the actual neutron energy spectrum.
1.2?The EBC is a characteristic of a homogeneous material. Characterization of inhomogeneous materials and calculation of neutron multiplication factors require techniques that are beyond the scope of this practice. 1.3?The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4?This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee. |
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2. Referenced Documents | ||||||||||
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