INDEPTH Demonstration – SCALE Users’ Group Meeting

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INDEPTH Demonstration –SCALE Users’ Group Meeting

Brandon Grogan, Jordan Lefebvre, Murray Purves*

Nuclear Security Modeling GroupNuclear Nonproliferation DivisionOak Ridge National [email protected]

*Previously at ORNL

3rd Annual SCALE Users’ Group WorkshopAugust 19-21, 2019

22 Nuclear Nonproliferation Division (NND)

Inverse Calculations are Essential to Forensic Analysis of Reactor-Origin Material• Forward calculation of reactor operation (ORIGEN)

– Input: Reactor operational parameters• Enrichment, power, irradiation time, burnup, cooling time

– Calculated output:• Nuclide inventories (fission products, activation products, actinides)• Gamma source spectrum• Neutron source spectrum

• Inverse calculation: Inverse Depletion Theory (INDEPTH) code– Input: nuclide inventories– Calculated output: reactor parameters


Standard Depletion Calculation with ARP / ORIGEN

ARP /ORIGEN

Reactor OperatingHistory

- Initial Enrichment- Power Levels- Irradiation Time- Cooling Time- Flux- Initial Isotopics- Pu Content- Pu-239 Vector

- ARP Library- Moderator Density

Isotop

es

NeutronGroups

Gamm

a

Groups

For Activation ProblemsFor MOX Problems


Inverse ARP / ORIGEN Optimization with INDEPTH

ARP /ORIGEN

Reactor OperatingHistory

- Enrichment (IE)- Power Level (SP)- Irradiation Time (IT)- Cooling Time (CT)- Flux- Initial Isotopics- Pu Content- Pu-239 Vector

IsotopesNeutron Groups

Gamma Groups INDEPTH

- Fixed Parameters- ARP Library- Moderator Density

Gam

ma

Spec

trum Optimization

For Activation ProblemsFor MOX Problems

Burnup (BU) = IT × SP


The INDEPTH Method

• Start with a measurement on an irradiation product (spent fuel, medical isotope, etc)

• Make an initial guess on the reactor* history• INDEPTH calls an ORIGEN run with the initial guess• Compare ORIGEN results to measured values• Adjust initial guess to better match ORIGEN values to

measurements using a gradient-based search• Iterate until the best match between ORIGEN values and

measurements is found

* In theory, “reactor” could be any irradiation of material with neutrons


Inverse Depletion Theory (INDEPTH) Code• The base INDEPTH code was written in Fortran• Runs on LINUX / Windows / Mac platforms• Originally, it was run from a command prompt and used text files as

inputs/outputs.• The Graphical User Interface (GUI) eases problem setup and

improves visualization of the solutions.– GUI is written in C++ and C++ Qt Software Development Kit (SDK)– Kitware’s VTK for 2-D plotting visualization


What Kinds of Inputs Do We Typically Use?

• Our sample data is usually one of two basic types of measurements:– Destructive Assay (DA) – Take a piece of the material to analyze in a chemistry lab– Non-destructive Assay (NDA) – Make a measurement without disturbing the fuel rod /

container / etc.• Gamma spectroscopy• Neutron multiplication

• We can get a lot of physical properties from the DA sample, most importantly– Actinides [U, Np, Pu, etc.]– Fission Products [Cs, Eu, Gd, etc.]

• The NDA results usually give us a much smaller list of isotopes– 2-5 fission products– Possibly some Pu isotopes from neutron multiplicity counting

Walkthrough of the INDEPTH GUI

1010Nuclear Nonproliferation Division (NND)

CSV file format3 column file

First column:isotope

Format:u-235

Second column:

Mass(g / MTIHM)

Third column:Absolute

Uncertainty(g / MTIHM)


CSV file format - ratio4 column file

First column:Numerator

isotope

Format:[isotope]-[mass number]

e.g. u-235

Third column:mass ratio

(g / g)

Fourth column:Absolute

uncertainty(g / g)

Second column:

Denominator isotope


Edit sample data & add to run list

Can also type into table

Add/remove table rows

Toggle ratio sample type

Add this table as a sample

input

Uncertainty is optional – set to

-1.0 if not present

BUT either allentries or no entries must

have it


Run setup: select scenarios for INDEPTH runsReactor database

can set some useful defaults

INDEPTH optimization parameters are set

here

Selected parameter sets are

displayed here

Add current parameter set to ‘Scenarios to run’

Parameters available depend

on fuel type (U/MOX)


‘View output’ sections can be monitored during INDEPTH runs

Run status

When run ongoing: data corresponds to

last ORIGEN run completed by

INDEPTH

Uncertainty estimates not available until

INDEPTH completion

Not all data is applicable (e.g.

MOX data for a U fuel run)


Plots for each individual run are dynamically updated

Mouse over chart points to see value

Use tabs to navigate between

views

INDEPTH Demonstration Problems


INDEPTH Demonstration Problem 1

• Purpose: Test one sample using multiple reactor types• Sample(s): Problem01.csv• ORIGEN Libraries:

– w15x15 (United States: Three Mile Island-1)– ge8x8-2 (United States: Browns Ferry-1)– agr (United Kingdom: Heysham A-1)– vver1000 (Russian Federation: vver1000)

• Optimize: Specific Power (SP), Initial Enrichment (IE), Irradiation Time(IT), and Cooling Time (CT)

• Questions to Consider:– Which reactor most likely produced this sample?


Sample Import – Problem 1


Run Setup – Problem 1


Results – Problem 1


INDEPTH Demonstration Problem 2

• Purpose: Test using multiple samples with measured data• Sample(s):

– Problem02a.csv– Problem02b.csv– Problem02c.csv– Problem02d.csv– Problem02e.csv

• ORIGEN Library: w15x15 (United States: Three Mile Island-1)• Optimize: Specific Power (SP), Initial Enrichment (IE), Irradiation Time(IT),

and Cooling Time (CT)• Questions to Consider:

– How do the INDEPTH results look using measured data?


Previous Work: High Burnup Fuel Rod Measurements• Objective: Compare INDEPTH Isotope Gamma

and Isotopic Reconstructions

• Segments of two rods from a 15 × 15 assembly were measured at ORNL:

– Passive NDA Gamma of Fuel Rods• Analyzed as relative gamma intensities (ratios) and with a

scaled Cs-137 calibration for one assembly

– DA Samples were taken at 5 locations:• IDMS Measurement of 41 Isotope Concentrations








INDEPTH Demonstration Problem 3• Purpose: Put what you’ve learned together to analyze multiple samples AND multiple

reactors in the same problem

• Sample(s): – Problem3a.csv– Problem3b.csv– Problem3c.csv

• ORIGEN Libraries: – candu37 (Canada: Darlington-1)– agr (United Kingdom: Heysham-1)– w15x15 (United States: Three Mile Island-1)

• Optimize: Specific Power (SP), Initial Enrichment (IE), Irradiation Time(IT), Cooling Time (CT)

• Questions to Consider:– Can you tell which sample came from which reactor?– Do you feel like you know how to use the code now?








Questions?• My Contact Info:

Brandon R. GroganNuclear Security Modeling Group Nuclear Nonproliferation DivisionOak Ridge National [email protected]@ornl.gov ß For Bug Reporting, Suggestions

mailto:[email protected]

mailto:[email protected]

Documents

INDEPTH Demonstration – SCALE Users’ Group Meeting