MAPEP and the Role of the Cognizant Radiochemist in the Analytical Laboratory P.C. Temple Warwick, PhD RESL Office of Nuclear Energy U.S. Department of Energy

2 Job of the Analytical Chemist “The responsibility of an analytical chemist is to accurately determine the analyte of interest in the sample being submitted for analysis. Lately, there has been a trend to excuse poor performance and rationalize inadequate chemical procedures or inaccurate work as acceptable.” David S. Sill

3 Cognizant Radiochemist First and foremost the cognizant radiochemist is a good scientist  Analytical Radiochemistry is an extremely difficult, challenging, and highly technical profession  Requires constant vigilance for sustained performance Ability, desire, and knowledge to question a result  Does the analytical result relate to what is in the sample?  Does the answer make sense?  What issues may affect the accuracy and precision? Reports only the results of the analytical work  Its easier to get the right answer when you know what it is

4 MAPEP MAPEP was specifically designed to address issues encountered in real world samples and rigorously test the entire analytical process of the participant laboratories.

5 MAPEP Tests the performance of the entire analytical process  Identify possible issues with a participant’s analytical process – Accuracy – False positives/non detects – Sensitivity of the measurement – Chemical form of the analyte – Chemical interferences  MAPEP is continually evolving to address the needs of the analytical community  MAPEP is an indispensable tool for the cognizant radiochemist Real world samples  Representative of samples that are of interest to DOE  Not laboratory control samples

6 Laboratory Control Sample vs. Real World Sample Real world sample Laboratory control sample

7 I-129 MAPEP identified that analysis of Iodine-129 in water was being performed for DOE Initial results showed poor analytical work  Provided technical assistance Quality of analytical work improved With out PT how can the quality of the analytical work be assessed?

8 Co-57 False Positive Testing Eu-152 Added as Interference

9 Co-57 vs. Eu-152

10 Inadequate Dissolution of the Sample Hydrolysis of large +3 and +4 ions Extremely insoluble hydroxide and oxides  Not soluble in HNO 3 Soluble elements/ions collocated in an insoluble host lattice  UO 2 +2 and Cs + Unknown until analysis is performed  Front end sample dissolution

11 Refractory Plutonium Talk Topic

12 MAPEP Verification Analyses

13 Uranium in Soil Two distinct fractions in soil that contain uranium  Acid soluble  Acid insoluble (HNO 3 and HCl) Addition of HF will dissolve insoluble fraction How long is long enough to completely dissolve the insoluble fraction using HNO 3 and HF?  Hours to weeks Ratio of fractions is unknown in a blind sample

14 Which powder is H 2 O Soluble

15 Which powder is H 2 O Soluble Powdered Sugar Al 2 O 3

16 Natural Uranium Isotopes by Alpha Spectrometry

17 Uranium in Soil Previous MAPEP soils contained a lower concentration of insoluble fraction  Approximately 30% MAPEP acceptance criteria is 30%  What is the difference between 29% and 30.5%?  Is 29% bias good enough? A warning should warrant concern from the laboratory  Within statistics of the measurement (5-10%)

18 Uranium in Soil Series-30 contains approximately 60% uranium in the insoluble fraction  Led to high failure rate ( ≈ 70% ) Improper sample dissolution  Acid digestions were inadequate 10 laboratories were successful  7 used total sample dissolution methods  3 analyzed the total sample with gamma spectrometry (only U-238)  1 potentially successful Series 30 showed participants the limitations of their methods

19 Natural Uranium Isotopes by Alpha Spectrometry

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26 Uranium Conclusions The mission of MAPEP Processes knowledge is not suitable for blind samples  A robust method doesn’t require processes knowledge  Accounts for unknown variables Equation for success  Cognizant radio chemist + robust method + Good PT = impeccable analytical work

27 MAPEP MAPEP holds quality analytical work above all else  Ethical imperative to promote the highest achievable quality It is not about HOW the quality analytical work is achieved MAPEP wants to see the success of all participants  Not at the cost of lower standards

28 Conclusion Historically participants rise to the challenge MAPEP will continue to emphasize the importance of total sample dissolution MAPEP is an invaluable tool The cognizant radiochemist

29 Questions? Talk Topic