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Understanding Radiochemistry: Ra-228 and Gas Proportional Counting


Using EPA Method 904.0, Radium-228 in Drinking Water, as an example, this course will provide participants with a general understanding of the theory behind the radioanalytical techniques used, and applicable requirements of TNI 2016 Standard Volume 1 Module 6 (V1M6). A mixture of theory-lecture and interactive exercises using real laboratory data examples will help participants see how analytical processes translate into actions, results, and records that one might encounter in a typical radioanalytical laboratory. It will also address typical challenges that may be encountered. This class will be of benefit both to radiochemistry laboratorians and radiochemistry assessors/ABs.

Topics addressed will include:

  • Method scope, application, and limitations
  • Method 904.0 radiochemical separations of radium and actinium;
  • Theory of chemical yield monitoring and chemical yield corrections;
  • Radioactive decay and decay progeny ingrowth for 228Ra;
  • Sample test source preparation;
  • Gas-flow proportional counter (GPC) set-up, performance checks, efficiency calibrations, and background determinations;
  • Calculation and reporting of results and associated statistics (i.e., counting uncertainty vs. combined uncertainty, critical level vs. minimum detectable concentration vs. SDWA Detection Limit, chemical yield);
  • Common problems and challenges encountered with this method;
  • TNI Standard Volume 1, Module 6 requirements as they relate to EPA Method 904.0.

Expected Learning Outcomes
Students will complete the course with an understanding of:

  • The general principles behind EPA Method 904.0 including
    o    Method 904.0 scope and application;
    o    The role of decay and ingrowth in Method 904.0;
    o    Radiochemical separation of radium and actinium and preparation of the sample test source;
    o    General principles behind gas-flow proportional counting;
    • Set-up, quality control and calibration requirements for gas-flow proportional counters;
    • Background determinations for gas-flow proportional counters;
    o    Chemical yield corrections used;
    o    A general familiarity with EPA Method 904.0 calculations of activity concentration.

  • And how V1M6 requirements relate to the Method 904.0 processes:
    o    Method scope, application, and limitations;
    o    Method validation;
    • Uncertainty;
    • Detection capability;
    o    Instrument controls: Instrument set-up, calibration, and performance checks;
    o    Sample specific controls: chemical yield;
    o    Sample measurements;
    o    Batch quality controls;
    o    Reviewing and reporting results.

Course Fee:
$195 for TNI members and $220 for non-members; $595 group rate for 5 or more students.

TNI Members: you must be logged-in to the website to receive the member rate.

About Webcasts:
 Upon receipt of your payment, you will receive a special link by e-mail to watch the webcast on your computer. The link is time-limited: you will have full access to the webcast and any associated handouts for 6 months after receipt of payment, at which time the link will expire. Webcasts cannot be downloaded; they are intended for viewing on your computer only during the 6-month window. If you have any questions, please contact Ilona Taunton at

No certificates are provided with webcasts. An additional $15 per person will be charged for anyone who desires a Certificate of Attendance (CoA) or Certificate of Completion (CoC) for the course. A passing score of 2/3 must be received on the Quiz in order to receive CEUs and a CoC. Contact Ilona Taunton at and provide a copy of your course receipt, date of course completion after you have completed the class and copy of your completed quiz.

Group rates are available: Each purchased webcast is to be viewed by only one student. If you would like multiple viewers, separate purchases must be made. A group rate of $595 is available for groups of 5 or more students at a single location. Click hereto purchase this webcast at the group rate.


9 hours

This course has been reviewed and approved by TNI.

Presented By:

TNI Radiochemistry Expert Committee

About the Presenter:
The mission of this committee is to maintain the radiochemistry standard (TNI Environmental Sector Volume 1, Module 6) based on public input; to provide technical assistance on issues related to radiochemistry; and, to develop tools that facilitate the implementation of the standard.