Background^(131)I is a critical radionuclide in nuclear medicine,particularly for thyroid disorder therapies.Chinese national standards mandate reducing^(131)I concentrations in radioactive waste liquid to below 10 Bq...Background^(131)I is a critical radionuclide in nuclear medicine,particularly for thyroid disorder therapies.Chinese national standards mandate reducing^(131)I concentrations in radioactive waste liquid to below 10 Bq/L.To address this requirement,rapid and precise quantification of^(131)I activity is essential for compliance monitoring and clinical safety.Methods A detection system integrating a NaI(Tl)crystal and a silicon photomultiplier array was developed to measure the^(131)I concentrations via its 364.5 keV characteristic\(\gamma\)-ray emissions.The setup incorporates 5 cm oxygen-free copper and 5 cm lead shielding to mitigate external\(\gamma\)-ray interference.Sample analysis utilizes a 50 mL aliquot,with system sensitivity evaluated under varying measurement durations.Results Under optimized shielding conditions,the system achieved a minimum detectable activity of 8.0 Bq/L for^(131)I within a 3-hour measurement period.Extending the acquisition time to 24 hours enhanced sensitivity to 2.8 Bq/L,surpassing the regulatory threshold requirement of 10 Bq/L.Conclusions The developed system demonstrates sufficient sensitivity and accuracy for monitoring^(131)I in radioactive waste liquids,aligning with national emission standards.The time-dependent sensitivity improvement highlights its adaptability for both rapid screening and low-concentration quantification,thus validating its applicability in nuclear medicine waste management.展开更多
基金the National Institute of Metrology of China for providing the standard^(131)I solutionsupported by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2023015).
文摘Background^(131)I is a critical radionuclide in nuclear medicine,particularly for thyroid disorder therapies.Chinese national standards mandate reducing^(131)I concentrations in radioactive waste liquid to below 10 Bq/L.To address this requirement,rapid and precise quantification of^(131)I activity is essential for compliance monitoring and clinical safety.Methods A detection system integrating a NaI(Tl)crystal and a silicon photomultiplier array was developed to measure the^(131)I concentrations via its 364.5 keV characteristic\(\gamma\)-ray emissions.The setup incorporates 5 cm oxygen-free copper and 5 cm lead shielding to mitigate external\(\gamma\)-ray interference.Sample analysis utilizes a 50 mL aliquot,with system sensitivity evaluated under varying measurement durations.Results Under optimized shielding conditions,the system achieved a minimum detectable activity of 8.0 Bq/L for^(131)I within a 3-hour measurement period.Extending the acquisition time to 24 hours enhanced sensitivity to 2.8 Bq/L,surpassing the regulatory threshold requirement of 10 Bq/L.Conclusions The developed system demonstrates sufficient sensitivity and accuracy for monitoring^(131)I in radioactive waste liquids,aligning with national emission standards.The time-dependent sensitivity improvement highlights its adaptability for both rapid screening and low-concentration quantification,thus validating its applicability in nuclear medicine waste management.
