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Updated: Jul 3, 2026
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Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films
Published on: November 9, 2015
Application of alpha track registration technique for plutonium estimation in bioassay samples
Pramilla D Sawant1, S P Prabhu, P C Kalsi
1Internal Dosimetry Division, BARC, Trombay, Mumbai, India. pooja@barc.gov.in
Summary
A new method using solid-state nuclear track detectors (SSNTDs) offers a sensitive alternative for plutonium (Pu) bioassay monitoring in nuclear workers. This technique provides comparable results to alpha spectrometry with a lower detection limit.
Area of Science:
- Nuclear Science and Technology
- Radiation Detection and Measurement
- Occupational Health and Safety
Background:
- Bioassay monitoring is crucial for occupational workers handling plutonium (Pu) in nuclear facilities.
- Current Pu estimation in India relies on alpha spectrometry, which has a minimum detectable activity (MDA) of 0.5 mBq for a 1-day counting period.
- The high sample counting load on alpha spectrometry necessitates the development of alternative methods.
Purpose of the Study:
- To develop an alternative method for plutonium bioassay monitoring using solid-state nuclear track detectors (SSNTDs).
- To reduce the sample counting burden associated with traditional alpha spectrometry.
- To assess the efficacy and sensitivity of the SSNTD-based method for Pu estimation.
Main Methods:
- Urine samples from normal subjects were spiked with known amounts of plutonium (0.5-5.5 mBq).
- Spiked samples were exposed to CR-39 SSNTDs for alpha track registration.
- Plutonium content was calculated by counting alpha tracks in CR-39 films and comparing with standards.
Main Results:
- The alpha track registration technique successfully quantified plutonium in spiked urine samples.
- Results obtained using SSNTDs showed good agreement with alpha spectrometry, within +/-30%.
- The minimum detectable amount of plutonium using this method was determined to be 0.18 mBq for a 45-day exposure period.
Conclusions:
- Solid-state nuclear track detectors (SSNTDs) offer a viable and sensitive alternative for plutonium bioassay.
- This method can effectively reduce the workload on alpha spectrometry in nuclear facilities.
- The SSNTD technique provides reliable Pu quantification with a lower minimum detectable activity compared to standard methods for extended counting periods.
