Nuclear Techniques ›› 2016, Vol. 39 ›› Issue (3): 30203-030203.doi: 10.11889/j.0253-3219.2016.hjs.39.030203

• LOW ENERGY ACCELERATOR, RAY AND APPLICATIONS • Previous Articles     Next Articles

Simulation of gamma spectra continuous monitoring in seawater

YANG Litao, CHEN Chaofeng, HUANG Yanjun, HE Yi, SHANGGUAN Zhihong   

  1. Suzhou Nuclear Power Research Institute, Suzhou 215004, China
  • Received:2015-10-19 Revised:2016-01-07 Online:2016-03-10 Published:2016-03-11

Abstract:

Background: With the public and environment protection departments pay more and more attention to radiation environment around the nuclear facilities, the gamma spectrum continuous monitoring is an important measure in marine environment. The method of continuous monitoring of gamma spectrum in ocean has been widely used in foreign countries, but seldom seen in our country. Purpose: This study aims to investigate the effective detection range, background spectrum, detection efficiency and the minimum detectable activity concentration of the marine gamma spectrum for the main artificial radionuclides around the nuclear facilities. Methods: The measurement models were established for different size of NaI scintillant detectors employed for on-line monitoring of gamma spectrum in ocean by Monte Carlo N Particle Transport Code (MCNP), targeting at the attenuation of various gamma-ray energies and effective detectivity in seawater. Results: The effective detection range of gamma rays in seawater was less than 70 cm. The minimum detectable activity concentrations for NaI scintillant detectors with crystal sizes of ø5.08 cm×5.08 cm, ø7.62 cm×7.62 cm, and ø15.24 cm×7.62 cm were in the range of 0.34-0.50 Bq·L-1, 0.19-0.30 Bq·L-1, and 0.07-0.11Bq·L-1, respectively. Conclusion: The MCNP was successfully applied to the study of marine gamma spectrum continuous monitoring methods. The simulation results provide technical reference for the application of continuous monitoring of gamma spectrometry in the ocean or other water systems.

Key words: Marine radionuclide, Continuous monitoring, MCNP, Crystal size, Detection limit

CLC Number: 

  • TL99