Validation of FISPACT-II Decay Heat Predictions for LWR Spent … · 2016. 9. 8. · Introduction Preliminary comments Validation results I Prediction of ﬁssion decay heat is essential

Introduction Preliminary comments Validation results

Validation of FISPACT-II Decay Heat Predictionsfor LWR Spent Fuel

Michael Fleming, Jean-Christophe Sublet

Culham Centre for Fusion EnergyCulham Science Centre

AbingdonOxfordshire OX14 3DB

29 April 2015

http://www.ccfe.ac.uk


Contents

Introduction

Preliminary comments

Validation results



I Prediction of fission decay heat is essential in safety analysisof reactors and considerable e↵ort has resulted in large (butnarrow) experimental data-set for fissions (cf CCFE-R(15)25for fusion decay heat)

I Decay heat simulation provides standard for validation offission yield data, decay data and simulation codes

I No two libraries produce the same inventories – although DHcan show uncanny similarity

I Complexity of inventory from fission makes deconvolution achallenge:



1E-06

1E-05

1E-04

1E-03

1E-02

1E-01

1E+00

1E+01

1E+02

1E+03

1E+04

1E-01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05 1E+06

Hea

t O

utp

ut

(kW

/kg)

Time after irradiation (s)

Heat Output (kW/kg) value/t-half for nuclide

131mTe

140Ba

132Te

129Sb

132I

91mY

135Xe

97mNb 97Zr

133I97

Nb

93Y

91Sr

92Y141La

135I

88Rb

88Kr

131Te

92Sr

139Ba

84Br

87Kr

130Sb

133mTe

101Tc

142La

146Pr

134I

134Te

105Tc

147Pr

138Cs

130mSb

131Sb

133Te

104Tc

132mSb

90mRb

89Rb

141Ba

143La

101Mo

94Y

102Tc

142Ba

138Xe

139Cs

148Pr

99mNb103Tc

145Ce

95Y

132Sb

133Sb

93Sr

137Xe

147Ce

90Rb

85Se

89Kr

103Mo

136I

86Br

87Br94

Sr98Zr

146mLa86

Se 136mI

140Cs

91Rb

144La

136Te

98Nb

145La

99Nb

139Xe

90Kr

137I146

La

135Te88Br141Cs

140Xe

144Ba

96mY 95Sr

143Ba101Nb

138I

100Nb

102Zr 100Zr89

Br102Nb96

Y

97Y

91Kr

145Ba

104mNb

100mY

93Kr

100Y

94Rb

143Cs

93Rb

98Sr

141Xe

92Rb

92Kr

102mNb

101Zr

103Nb

99Y99

Zr98

Y98m

Y142

Cs95

Rb

97nY 97m

Y96

Sr

97Sr

I 235Uth pulse using JEFF-3.1.1 DD+nFY



1E-06

1E-05

1E-04

1E-03

1E-02

1E-01

1E+00

1E+01

1E+02

1E+03

1E+04

1E-01 1E+00 1E+01 1E+02 1E+03 1E+04 1E+05 1E+06

Hea

t O

utp

ut

(kW

/kg)

Time after irradiation (s)

Heat Output (kW/kg) Greenwood

93Rb

95Sr

143Ba144Ba

145Ba

95Y

94Y

93Sr

94Sr

91Rb

90mRb

90Rb

89Rb

138Cs

139Cs

140Cs

141Cs

146Pr

147Pr

148Pr

141Ba

142Ba

145Ce

147Ce

142La

143La

144La

145La

WPEC SG 25 P1

86Br

87Br

88Br

89Kr

90Kr

100Nb

101Nb

105Tc

104Tc

103Tc

103Mo

102Tc

99Nb

98Nb

132Sb

136I

136mI

137I

137Xe

139Xe

140Xe

WPEC SG 25 P297Sr92

Rb

96Y

102Nb

WPEC SG 25 P399Zr142

Cs

I Greenwood/WPEC25 priority nuclides shown



Fission decay heat has been the subject of several experiments overseveral decades. Even those experiments with the same fissile areall unique, notably di↵ering in:

I Irradiation duration and flux spectrum

I Measurement techniques

I Fission rate determination

I Sample preparation/removal/post-irradiation processing

I Contamination corrections (capture/epithermal/impurity)

ICorrection methodology (finite to pulse, noble loss, etc)



Author Method Nuclide(s) Irr. (s) Year

Yarnell, LANL Calor. 233U 235U 239Pu 2E4 1980Dickens, ORNL �,� 235U 239Pu 241Pu 1-100 1980Baumung, KfK Calor. 235U 200 1981Akiyama, YAYOI �,� 232Th 233U 235U 10-300 1982

238U 239PuJohansson, Uppsala �,� 235U 238U 239Pu 4-120 1987

Schier, Lowell �,� 235U 238U 239Pu


0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1 10 100 1000 10000 100000

Dec

ay h

eat

(MeV

/fis

sion)

Time (s)

100 ms Irradiation1 s Irradiation

10 s Irradiation100 s Irradiation

1000 s IrradiationBurst Function

Dickens total

I 241Pu thermal fission

I No individual experiment covers pulse



0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0.1 1 10 100 1000 10000 100000

Tota

l dec

ay h

eat

(MeV

/fis

sion)

Time (s)

JEFF3.1.1ENDFB7.1JENDL4.0DECAY12

Tobias totalDickens total

I Capture contamination depends upon preciseknowledge of inventory and spectrum (235U shown)



FISPACT-II is a general-purpose simulation code, completelyrewritten from legacy FISPACT in modern Fortran

I Can use any ENDF-format nuclear data

I Calculates numerous observables: activity, heat, various doses,detailed inventory, sophisticated pathway trees

I RRR+URR self-shielding with PT from CALENDF

I Generate sources with multi-di↵erential data

I Developed to accommodate a complete, technological library(eg TENDL) with all isomeric states, HFR, double-di↵ ...

I Provides robust simulation methodology that can be appliedto reactor operation, activation/transmutation, fusionapplications, high-energy, security, astrophysics ...



0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0.1 1 10 100 1000 10000 100000

Tota

l dec

ay h

eat

(MeV

/fis

sion)

Time (s)

JEFF3.1.1GEF4.2

UKFY4.2Tobias total

Dickens total

I 235U thermal pulse total heat

I Varied nFY with JEFF-3.1.1 DD simulation



0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0.1 1 10 100 1000 10000 100000

Bet

a d

ecay

hea

t (M

eV/f

issi

on

)

Time (s)

JEFF3.1.1ENDFB7.1JENDL4.0DECAY12Tobias betaLowell beta

Dickens beta

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.1 1 10 100 1000 10000 100000

Gam

ma

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)


Tobias gammaLowell gamma

Dickens gamma

I JEFF-3.1.1 nFY simulation 235U pulse beta (L) gamma (R)

I Well-known Pandemonium �-deficiency can be probedthrough multi-library comparison



0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0.75

0.8

1 10 100

Gam

ma

dec

ay h

eat

(MeV

/fis

sion)

Time (s)


Tobias gammaLowell gamma

Dickens gamma

I Example: isolate �-heat of 235U pulse at 10susing same nFY to compare DD



Nuclide JEFF3.1.1 ENDFB7.1 JENDL4.0 DECAY12

Rb92 3.12 3.85 3.85 3.13Rb93 3.21 3.11 2.80 3.21Nb102 1.56 2.50 0.64 1.56Y96 0.15 0.15 2.23 0.15Kr91 1.98 1.99 2.00 1.98Y96m 1.93 1.85 1.85 1.93Ba143 2.13 2.13 1.81 1.77Nb102m 0.64 0.06 0.95 0.06

I Normalised heat output in W/fission for 235U pulse at 10s

I Some appear corrected only in JENDL/ENDF, some may bere(mis?)-allocation to isomer, such as Nb102m.



0.25

0.3

0.35

0.4

0.45

0.5

0.55

0.6

0.65

0.7

0.75

0.8

1 10 100

Gam

ma

dec

ay h

eat

(MeV

/fis

sion)

Time (s)

JEFF3.1.1GEF4.2

UKFY4.2Tobias gammaLowell gamma

Dickens gamma

I Same story, but now variety of nFY for�-heat of 235U pulse at 10s



Nuclide JEFF3.1.1 GEF4.2 UKFY4.2

Rb92 3.12 2.90 3.34Rb93 3.21 3.14 3.95Sr95 1.91 2.08 2.14Y97 1.14 1.88 1.64

Nb102 1.56 1.23 0.58Kr91 1.98 1.87 1.64Y96m 1.93 0.38 4.37Ba143 2.13 1.99 1.97

I Normalised heat output in W/fission for 235U pulse at 10s

I Uncanny di↵erences in dominant fission production yields,isomeric yields?



0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)


Akiyama total

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)


Akiyama total

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)


Akiyama total

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)


Akiyama total

I Akiyama 3,5,8,9 vs 400keV (JEFF nFY)



0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)

JEFF3.1.1GEF4.2

UKFY4.2Akiyama total

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)

JEFF3.1.1GEF4.2


0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)

JEFF3.1.1GEF4.2


0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

10 100 1000 10000

To

tal

dec

ay h

eat

(MeV

/fis

sio

n)

Time (s)

JEFF3.1.1GEF4.2


I Akiyama 3,5,8,9 vs 400keV nFY (JEFF DD)



Some thoughts:

I Decay heat experiments are complex, old(er than me), andcould benefit from review for specific fuels/times

I Meta-analysis of experiments with systematic challenges doesnot improve data quality

I Integration of new decay data needed for �/� heat

I Di�cult to assign superiority of files due to spread ofexperimental data

I FISPACT-II allows versatile simulation which can probe DHsubtleties and expose unresolved issues with DD and/or nFY

http://www.ccfe.ac.uk/EASY.aspx



Thank you for your attention


IntroductionPreliminary commentsValidation results

Documents

Validation of FISPACT-II Decay Heat Predictions for LWR Spent … · 2016. 9. 8. · Introduction Preliminary comments Validation results I Prediction of ﬁssion decay heat is essential