ASTM E705-13a
Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237

Standard No.

ASTM E705-13a

Release Date

2013

Published By

American Society for Testing and Materials (ASTM)

Status

Be replaced

Replace By

ASTM E705-18

Latest

ASTM E705-18

Scope

5.1 Refer to Practice E261 for a general discussion of the determination of fast-neutron fluence rate with fission detectors.

5.2 ²³⁷Np is available as metal foil, wire, or oxide powder. For further information, see Guide E844. It is usually encapsulated in a suitable container to prevent loss of, and contamination by, the 8201;²³⁷Np and its fission products.⁴

5.3 One or more fission products can be assayed. Pertinent data for relevant fission products are given in Table 1 and Table 2.

5.3.1 ¹³⁷Cs-^137mBa is chosen frequently for long irradiations. Radioactive products ¹³⁴Cs and 8201;¹³⁶Cs may be present, which can interfere with the counting of the 0.662 MeV 8201;¹³⁷Cs-^137mBa gamma ray (see Test Methods E320).

5.3.2 ¹⁴⁰Ba-¹⁴⁰La is chosen frequently for short irradiations (see Test Method E393).

5.3.3 ⁹⁵Zr can be counted directly, following chemical separation, or with its daughter ⁹⁵Nb, using a high-resolution gamma detector system.

5.3.4 ¹⁴⁴Ce is a high-yield fission product applicable to 2- to 3-year irradiations.

5.4 It is necessary to surround the ²³⁷Np monitor with a thermal neutron absorber to minimize fission product production from trace quantities of fissionable nuclides in the ²³⁷Np target and from 8201;²³⁸Np and 8201;²³⁸Pu from (n,γ) reactions in the 8201; ²³⁷Np material. Assay of 8201;²³⁸Pu and 8201; ²³⁹Pu concentration is recommended when a significant contribution is expected.

5.4.1 Fission product production in a light-water reactor by neutron activation products 8201;²³⁸Np and 8201; ²³⁸Pu has been calculated to be insignificant (1.28201;%), compared to that from 8201;²³⁷Np(n,f), for an irradiation period of 12 years at a fast neutron (E gt; 1 MeV) fluence rate of 18201;×8201;10¹¹ cm⁻² ·s⁻¹, provided the 8201;²³⁷Np is shielded from thermal neutrons (see Fig.8201;2 of Guide E844).

5.4.2 Fission product production from photonuclear reactions, that is, (γ,f) reactions, while negligible near-power and research reactor cores, c......

<......

ASTM E705-13a Referenced Document

• ASTM E1005 Standard Test Method for Application and Analysis of Radiometric Monitors for Reactor Vessel Surveillance, E 706(IIIA)
• ASTM E1018 Standard Guide for Application of ASTM Evaluated Cross Section Data File, Matrix E 706 (IIB)
• ASTM E170 Standard Terminology Relating to Radiation Measurements and Dosimetry
• ASTM E181 Standard Test Methods for Detector Calibration and Analysis of Radionuclides
• ASTM E261 Standard Practice for Determining Neutron Fluence, Fluence Rate, and Spectra by Radioactivation Techniques
• ASTM E262 Standard Method for Determining Thermal Neutron Reaction and Fluence Rates by Radioactivation Techniques
• ASTM E320 Test Method for Cesium-137 in Nuclear Fuel Solutions by Radiochemical Analysis
• ASTM E393 Standard Test Method for Measuring Reaction Rates by Analysis of Barium-140 From Fission Dosimeters
• ASTM E704 Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
• ASTM E844 Standard Guide for Sensor Set Design and Irradiation for Reactor Surveillance, E 706(IIC)
• ASTM E944 Standard Guide for Application of Neutron Spectrum Adjustment Methods in Reactor Surveillance, (IIA)

ASTM E705-13a history

• 2018 ASTM E705-18 Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
• 2013 ASTM E705-13a Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
• 2013 ASTM E705-13 Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
• 2008 ASTM E705-08 Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
• 1996 ASTM E705-96(2002) Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
• 1996 ASTM E705-96 Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237