Method for measuring 237Np calibrated by 242Pu

Abstract

The invention discloses a method for measuring 237Np calibrated by 242Pu. The method comprises the following steps of weighing sample to remove organic matters, a 242Pu tracer agent being added, concentrated nitric acid post-heating, filtering supernatant liquid twice, heating and evaporating the filtrate to be slightly dry, adding concentrated nitric acid and pure water, and mixing to adjust theacidity to 5M HNO3 solution, adding 0.06 M ascorbic acid to adjust the valence state, filling TEVA resin, 0.5 M of HCl, 9M of HCl and 5M of HNO3 being added, loading the solution of which the valencestate is adjusted onto an exchange column, adding 5M of HNO3, 9M of HCl and 1M of HNO3 to wash off impurities, finally, adding 0.5 M of HCl to elute 237 Np, transferring into a centrifugal tube, adding 1.5 mg / mL of Al<3+> solution, heating for 48 hours, evaporating to dryness, transferring into a quartz crucible, heating, doping 0.5 mg of Al<3+> into the heated aluminum oxide, fully mixing, pressing the mixed sample into a sample target through a target pressing device, and performing AMS measurement after target loading is finished. The method is advantaged in that the interference of similaralpha energy nuclide is avoided, the interference of molecular ions in inductively coupled plasma mass spectrometry measurement is avoided, and measurement sensitivity is improved.

Description

technical field [0001] The invention relates to the technical field of nuclear and radiation safety assessment, in particular to a 242 Pu calibration 237 Np measurement method. Background technique [0002] 237 Np is an artificial radionuclide closely related to the nuclear industry, and its half-life is 2.14×10 6 year. in the environment 237 Np is mainly produced by atmospheric nuclear tests, waste from nuclear industry and nuclear leaks. Neptunium and its isotopes are radiotoxic and biologically toxic, and are easy to accumulate in the bones and liver of the human body, and it is difficult for the human immune system to eliminate them. Internal radiation produced in the human body for a long time will increase the chance of human cancer. because 237 Np has a long half-life, so the environment 237 The determination of Np is of great significance to nuclear and radiation safety assessment. At this stage, mainly through environmental samples 237 Np determination, to...

AI Technical Summary

Problems solved by technology

[0020] The present invention provides a kind of 242 Pu calibration 237 The Np measurement method solves the problem of insufficient detection limits of the α spectrum analysis method and the neutron activation method, and is suitable for environmental samples in unpolluted areas. 237 The determination of Np provides a set of effective determination methods

use 242 Pu substitute 239 Np tracer, which solves the neutron activation method 239 The short half-life of Np (about 2.355 days) leads to the problem of error in the analysis

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