The Takahama-3 Benchmark: Validating DRAGON for

Nonproliferation and Neutrino OscillationsChristopher JonesAAP 2011, Wien

September 16, 2011

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Ndetν (E, t) = Nemit

ν (E, t) · dσ

dΩ· dΩ · Nprotons · det

From a simulation code (e.g., DRAGON)

The Role of Reactor Simulations In Antineutrino Technology

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arXiv:1003.1391v1arXiv:hep-ex/0701029v1 arXiv:hep-ex/0606025v4

Nuclear engineers want codes to assure stable running and criticality

and provide safety margins.

Neutrino physicists want codes to predict an antineutrino flux and assign it

a systematic uncertainty, even if they have a near-far design.

Nonproliferation through reactor monitoring also benefits

from this effort.

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• Deterministic lattice code that calculates neutron flux in an assembly of heterogeneous cells

• Solves Bateman equations for burnup

• Using customized version to extract fission rates

Fuel Cell

http://www.polymtl.ca/nucleaire/DRAGON/en/index.php

DRAGON Basics

G. Marleau, R. Roy and A. Hébert, DRAGON: A Collision Probability Transport Code for Cell and Supercell Calculations, Report IGE-157, Institut de génie nucléaire, École Polytechnique de Montréal, Montréal, Québec (1994)

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Why are we excited about DRAGON?

1) It is a multiplatform open-source code.You can download it today!

2) It is fast, allowing quick calculations of systematic errors.

It is an order of magnitude faster than MCNP-based code.

But is it accurate enough?

http://www.polymtl.ca/nucleaire/DRAGON/en/index.php

(On a 2.8 GHz processor, the simulation ran in 27.5 hr)

Days100 200 300 400 500

]-1

Antin

eutri

no R

ate

[day

s

310

320

330

340

350

360SONGS Data vs. Simulation

DRAGON Systematic ErrorSONGS Data

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-Assume 2% uncertainty on thermal power (red band); only Cycle 12 prediction shown here for clarity

DRAGON Prediction for SONGS Cycle 12

Suppressed zero!

Time dependence agrees well!

Cycle 12

Cycle 13

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How can we be sure that our absolute predictions with DRAGON are correct?

SONGS gave us some confidence that we can get time-dependent behavior correct.

days

Rate

0.0e+00

2.0e+14

4.0e+14

6.0e+14

8.0e+14

1.0e+15

1.2e+15

1.4e+15

500 1000 1500

Isotope

P239

P241

U235

U238

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• The Takahama-3 reactor is a reactor in Japan.

• They removed 3 fuel rods for a destructive assay from 2 of the assemblies.

• The results are publicly available!

• We (and many others) can compare our simulations to what they found!

• This is a very valuable method that allows us to assign systematic errors in

DRAGON’s fission rate and mass inventory predictions.

What Is the Takahama Benchmark?

Destructive Assay of Fuel Rods

After the reactor was shut down, the fuel rods in the benchmark underwent a chemical analysis.

From each rod, the fuel amounts along the axis were extracted at several points. Shown here is rod SF97.

Destructive Assay of Fuel Rods

After the reactor was shut down, the fuel rods in the benchmark underwent a chemical analysis.

From each rod, the fuel amounts along the axis were extracted at several points. Shown here is rod SF97.

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Takahama-3 Reactor Assembly Details

guide tube filled with borated water

2.63% enriched Gd-U burnable absorber rod

4.11% enriched fuel rod

17 x 17 PWR264 fuel rods per assembly157 assemblies in the core

~3.648 m in height

2.652 GWth

~460 kg U per assembly

~95% theoretical fuel density

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Takahama-3 Assembly NT3G24: Rod SF97

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Takahama-3 Assembly NT3G24: Rod SF97

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Irradiation Times

The reactor was evolved for 1343 days.This corresponds to 3 fuel cycles.

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We see good agreement compared to other codes!

MURE and DRAGON are the codes to be used in the Double Chooz reactor simulations.

Sample0 1 2 3 4 5 6 7

Ratio

Sim

ulat

ion

to M

easu

rmen

t

0.8

1

1.2

1.4U235

MUREHELIOSMONTEBURNSSCALEORIGENDRAGON

Sample0 1 2 3 4 5 6 7

Ratio

Sim

ulat

ion

to M

easu

rmen

t

0.8

1

1.2

1.4Pu239

MUREHELIOSMONTEBURNSSCALEORIGENDRAGON

Sample0 1 2 3 4 5 6 7

Ratio

Sim

ulat

ion

to M

easu

rmen

t

0.8

1

1.2

1.4Pu241

MUREHELIOSMONTEBURNSSCALEORIGENDRAGON

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Systematic Variations Along SF97

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2

1.3U235

Power Variation 3%Density Variation 1.5%Temperature Variation 30KBoron Variation 10%JENDL

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2

1.3Pu239

Power Variation 3%Density Variation 1.5%Temperature Variation 30KBoron Variation 10%JENDL

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2

1.3Pu241

Power Variation 3%Density Variation 1.5%Temperature Variation 30KBoron Variation 10%JENDL

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We used ENDF/B-VI. Are our results sensitive to choice of cross section library?

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2U235

Nominal - ENDF

JENDL

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2Pu239

Nominal - ENDF

JENDL

Position from Top of Rod [mm]0 500 1000 1500 2000 2500 3000 3500

Rat

io S

imul

atio

n to

Mea

sure

men

t

0.9

1

1.1

1.2Pu241

Nominal - ENDF

JENDL

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How will the variations affect our fission rate predictions?

Irradiation Time [days]0 200 400 600 800 1000 1200 1400

per

s13

10

!In

stan

tane

ous N

umbe

r of F

issi

ons

0

0.5

1

1.5

2

2.5

U235

Irradiation Time [days]0 200 400 600 800 1000 1200 1400

per

s13

10

!In

stan

tane

ous N

umbe

r of F

issi

ons

0

0.2

0.4

0.6

0.8

1

Pu239

Irradiation Time [days]0 200 400 600 800 1000 1200 1400

per

s13

10

!In

stan

tane

ous N

umbe

r of F

issi

ons

0

0.1

0.2

0.3

Pu241

These results are specific to Takahama.You can get DRAGON from us to run your simulation!

+3% power variation

-3% power variationcentral values

Conclusions• DRAGON is fast, free, and accurate. It

performs as well as industry standards. The code will be available soon!

• Physicists can modify DRAGON to serve the reactor neutrino industry.

• Given accurate inputs, DRAGON can offer reliable predictions for fission rates for use in neutrino oscillation experiments and nonproliferation efforts.

Thanks...

• to Janet Conrad and Lindley Winslow at MIT,

• to Adam Bernstein and the LLNL ADG,

• to Muriel Fallot and the MURE team at Subatech,

• to Thierry Laserre and the AAP 2011 conveners.