ML20042C434
| ML20042C434 | |
| Person / Time | |
|---|---|
| Issue date: | 02/05/2020 |
| From: | David Esh Office of Nuclear Material Safety and Safeguards |
| To: | Priya Yadav Division of Decommissioning, Uranium Recovery and Waste Programs |
| Yadav P | |
| Shared Package | |
| ML20042C425 | List: |
| References | |
| Download: ML20042C434 (3) | |
Text
From:
Esh, David To:
Yadav, Priya Cc:
Arlt, Hans
Subject:
FW: RE: RSD request, RAI 2-15 Date:
Wednesday, February 5, 2020 1:12:50 PM Attachments:
RPP-6924_-_Rev_01.pdf C-109ResidAnalyticalPu-138Densitycalc.xlsx Please add to your RAI response file.
From: Field, Jim G <jim_g_field@rl.gov>
Sent: Thursday, November 21, 2019 12:01 PM To: Esh, David <David.Esh@nrc.gov>
Cc: Bergeron, Marcel P <marcel_p_bergeron@rl.gov>; DeFord, Douglas K
<douglas_k_deford@rl.gov>; Arlt, Hans <Hans.Arlt@nrc.gov>; Gladney, Robert
<Robert.Gladney@nrc.gov>; Ross, Sherri R. (HQ) <sherri.ross@em.doe.gov>; Lobos, Rodrigo A
<rodrigo_a_lobos@orp.doe.gov>
Subject:
[External_Sender] RE: RSD request, RAI 2-15
- Dave,
The RSD results are different because the BBI uses Searle Equations for standard deviation and RSD calculations for analytical results.
Sorry for the delayed response; the calculations are programmed and automated and it took us awhile to figure out how to duplicate them.
As stated in Section 6.0 of RPP-6924 (attached), Searle equations are used to provide a closed-form solution to the unbalanced one-way analysis of variance situation for estimating the treatment (lab sample id) and error (primary/duplicate/triplicate) variance components. These variance component estimates are then incorporated into weights used in the Generalized Least Squares Estimator methodology (Searle, Casella, and McCulloch, 1992, page 54) to produce the estimated overall mean and SD.
Attached is RPP-6924, Statistical Methods for Estimating the Uncertainty in the Best Basis Inventories. Also attached is an Excel file showing how RSD values were calculated for bulk density and Pu-238 for tank C-109.
Note: there are 3 composite samples, but 4 sample values for Pu-238 because composite #2 had both primary and duplicate sample results. Also note: volume RSDs for C-Farm data do not use the pre-retrieval estimates in the tables in RPP-6924; volume RSDs are based on video measurements (CCMS).
Contact me if you have questions.
- Thanks,
Jim Field
376-3753 Production Operations Process Engineering Washington River Protection Solutions Contractor to the U. S. Department of Energy
From: Esh, David <David.Esh@nrc.gov>
Sent: Friday, November 08, 2019 6:58 AM To: Field, Jim G <jim_g_field@rl.gov>
Cc: Bergeron, Marcel P <marcel_p_bergeron@rl.gov>; DeFord, Douglas K
<douglas_k_deford@rl.gov>; Arlt, Hans <Hans.Arlt@nrc.gov>; Gladney, Robert
<Robert.Gladney@nrc.gov>
Subject:
RE: RSD request, RAI 2-15
Hi Jim - Thanks for following up. I was looking at C-109, and Pu-238 as an example.
For the three composite samples DOE has densities of 1.66, 1.79, 1.78. We both have a mean of 1.74 for that. However DOE calculates a RSD of.0239 whereas a simple RSD I have as 0.0415.
For the Pu-238 concentrations they are in the sampling report as 1.19E-3, 1.64E-3, and 8.85E-4. DOE calculates a RSD of 0.157 whereas I have 0.307.
If I assign probability distributions for density and concentrations and propagate it I would get an overall standard deviation that is 86% higher than DOE. I am trying to understand the DOE RSDs. They seem to be lower across the board, and if you only have three sample results for a tank I am not clear how you can come up with a much lower variance for each tank. Each tank is unique more or less.
The problem (if it is one) is a bit worse if you assume the concentrations are log-normally distributed. The 95th percentile concentrations are higher.
Thanks for looking at this - I am off next week so no hurry on a response,
Dave
From: Field, Jim G <jim_g_field@rl.gov>
Sent: Thursday, November 07, 2019 5:55 PM To: Esh, David <David.Esh@nrc.gov>
Cc: Bergeron, Marcel P <marcel_p_bergeron@rl.gov>; DeFord, Douglas K
<douglas_k_deford@rl.gov>
Subject:
[External_Sender] RSD request, RAI 2-15
- Dave,
AS discussed in todays call, please send specific information re. your request for how RSDs were
determined for Tank C-110 or C-111 sample analyses.
Also, identify the source of RSD information you are trying to duplicate. I should be able to get something back to you early next week.
- Thanks,
Jim Field 376-3753 Production Operations Process Engineering Washington River Protection Solutions Contractor to the U. S. Department of Energy