Developed by Subcommittee: C26.05
WITHDRAWN, NO REPLACEMENT
This test method covers the determination of the number of atoms of???137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated.
Formerly under the jurisdiction of Committee
1.1 This test method covers the determination of the number of atoms of 137Cs in aqueous solutions of irradiated uranium and plutonium nuclear fuel. When combined with a method for determining the initial number of fissile atoms in the fuel, the results of this analysis allows atom percent fission (burn-up) to be calculated (1). The determination of atom percent fission, uranium and plutonium concentrations, and isotopic abundances are covered in Test Methods E 267
1.2 137Cs is not suitable as a fission monitor for samples that may have lost cesium during reactor operation. For example, a large temperature gradient enhances 137Cs migration from the fuel region to cooler regions such as the radial fuel-clad gap, or, to a lesser extent, towards the axial fuel end.
1.3 A nonuniform 137Cs distribution should alert the analyst to the potential loss of the fission product nuclide. The 137Cs distribution may be ascertained by an axial gamma-ray scan of the fuel element to be assayed. In a mixed-oxide fuel, comparison of the 137Cs distribution with the distribution of nonmigrating fission-product nuclides such as 95Zr or 144Ce would indicate the relative degree of 137Cs migration.
1.4 The values stated in SI units are to be regarded as standard. No other unites of measurement are included in this standard.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
E170 Terminology Relating to Radiation Measurements and Dosimetry
E181 Test Methods for Detector Calibration and Analysis of Radionuclides
E219 Test Method for Atom Percent Fission in Uranium Fuel (Radiochemical Method) (Discontinued 2001)
E267 Test Method for Uranium and Plutonium Concentrations and Isotopic Abundances
E321 Test Method for Atom Percent Fission in Uranium and Plutonium Fuel (Neodymium-148 Method)