5.1 The typical use of this test method is determination of ¹⁰B areal density in aluminum neutron absorber materials used to control criticality in systems such as: spent nuclear fuel dry storage canisters, transfer/transport nuclear fuel containers, spent nuclear fuel pools, and fresh nuclear fuel transport containers.

5.2 Areal density measurements are also used in the investigation of the uniformity in ¹⁰B spatial distribution.

5.3 The expected users of this standard include designers, suppliers, neutron absorber users, testing labs, and consultants in the field of nuclear criticality analysis.

5.4 Another known method used to determine areal density of ¹⁰B in aluminum neutron absorbers is an analytical chemical method as mentioned in Practice C1671. However, the analytical chemical method does not measure the “effective” ¹⁰B areal density as measured by neutron attenuation.

1.1 This test method is intended for quantitative determination of effective boron-10 (¹⁰B) areal density (mass per area of ¹⁰B, usually measured in grams-¹⁰B/cm² ) in aluminum neutron absorbers. The attenuation of a thermal neutron beam transmitted through an aluminum neutron absorber is compared to attenuation values for calibration standards allowing determination of the effective ¹⁰B areal density. This test is typically performed in a laboratory setting. This method is valid only under the following conditions:

1.1.1 The absorber contains ¹⁰B in an aluminum or aluminum alloy matrix.

1.1.2 The primary neutron absorber is ¹⁰B.

1.1.3 The test specimen has uniform thickness.

1.1.4 The test specimen has a testing surface area at least twice that of the thermal neutron beam’s surface cross-sectional area.

1.1.5 The calibration standards of uniform composition span the range of areal densities being measured.

1.1.6 The areal density is between 0.001 and 0.080 grams of ¹⁰B per cm².

1.1.7 The thermalized neutron beam is derived from a fission reactor, sub-critical assembly, accelerator or neutron generator.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.3 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.