ASTM E704-08
Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
- Standard No.
- ASTM E704-08
- Release Date
- 2008
- Published By
- American Society for Testing and Materials (ASTM)
- Status
- Replace By
- ASTM E704-13
- Latest
- ASTM E704-19
- Scope
Refer to Practice E 261
for a general discussion of the determination of fast-neutron fluence rate with fission detectors. 238U is available as metal foil, wire, or oxide powder (see Guide E 844
). It is usually encapsulated in a suitable container to prevent loss of, and contamination by, the 238U and its fission products. One or more fission products can be assayed. Pertinent data for relevant fission products are given in Table 1 and Table 2.
137Cs-137mBa is chosen frequently for long irradiations. Radioactive products 134Cs and 136Cs may be present, which can interfere with the counting of the 0.662 MeV 137Cs-137, Ba gamma rays (see Test Methods E 320
). 140Ba-140La is chosen frequently for short irradiations (see Test Method E 393
). 95Zr can be counted directly, following chemical separation, or with its daughter 95Nb using a high-resolution gamma detector system.
144Ce is a high-yield fission product applicable to 2- to 3-year irradiations.
It is necessary to surround the 238U monitor with a thermal neutron absorber to minimize fission product production from a quantity of 235U in the 238U target and from 239Pu from (n,γ) reactions in the 238U material. Assay of the 239Pu concentration when a significant contribution is expected.
Fission product production in a light-water reactor by neutron activation product 239Pu has been calculated to be insignificant (<2 %), compared to that from 238U(n,f), for an irradiation period of 12 years at a fast-neutron (E > 1 MeV) fluence rate of 1 × 1011 cm−2 · s−1 provided the 238U is shielded from thermal neutrons (see Fig. 2 of Guide E 844
). Fission product production from photonuclear reactions, that is, (γ,f) reactions, while negligible near-power and research-reactor cores, can be large for deep-water penetrations (1).
1.1 This test method covers procedures for measuring reaction rates by assaying a fission product (F.P.) from the fission reaction 238U(n,f)F.P.
1.2 The reaction is useful for measuring neutrons with energies from approximately 1.5 to 7 MeV and for irradiation times up to 30 to 40 years.
1.3 Equivalent fission neutron fluence rates as defined in Practice E 261
can be determined. 1.4 Detailed procedures for other fast-neutron detectors are referenced in Practice E 261
. 1.5 The values stated in SI units are to be regarded as standard. No other unites of measurement are included in this standard.
1.6 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.
ASTM E704-08 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 E705 Standard Test Method for Measuring Reaction Rates by Radioactivation of Neptunium-237
- 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 E704-08 history
- 2019 ASTM E704-19 Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
- 2013 ASTM E704-13 Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
- 2008 ASTM E704-08 Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
- 1996 ASTM E704-96(2002) Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
- 1996 ASTM E704-96 Standard Test Method for Measuring Reaction Rates by Radioactivation of Uranium-238
