2.8.2.7. Block 13 — PMATCM — Fuel and Cladding Properties

Note: Suggested values refer to oxide fuel.

1

COEFDS (1)

kg/m^3

Solid fuel theoretical density at the reference temperature. Suggested value: 11.08E+3. Theoretical fuel density = COEFDS(1) / [1.0 + (COEFDS(2) + COEFDS(3) * (TK-273.15)) * (TK-273.15)].

2

COEFDS (2)

1/K

First-order solid fuel volumetric thermal expansion coefficient, ALPHA1. Suggested value: 2.04E-5.

3

COEFDS (3)

1/K^2

Second-order solid fuel volumetric thermal expansion coefficient, BETA1 Suggested value: 8.70E-9. Used only if IRHOK > 0.

4-10

COEFK (1-7)

Fuel thermal conductivity coefficients. Fuel thermal conductivity = ((COEFK(1) - FDEN) * FDEN - 1.0) * ((COEFK(2) + COEFK(3) * TK)^-1 + COEFK(4) * TK³) if FDEN ≤ 0.95, and thermal conductivity = (3.0 * FDEN -1.0) * ((COEFK(5) + COEFK(6) * TK)^-1 + COEFK(7) * TK³) if FDEN > 0.95, where FDEN is fractional fuel density. Suggested values: 2.1, 2.88E-3, 2.52E-5, 5.83E-10, 5.75E-2, 5.03E-4, 2.91E-11. Used only if IRHOK = 2.

11-70

EXKTB (L,ICLAD)

W/m-K

Table of clad thermal conductivity values for clad ICLAD, 1 ≤ L ≤ 20. See EXKTM for corresponding temperature values.

If only EXKTB(1) is entered, property is temperature-independent.

(1 ≤ ICLAD ≤ ICLAD1)

71-90

EXKTM (L)

K

Temperature values for EXKTB table, 1 ≤ L ≤ 20.

91-250

RHOTAB (L,IFUEL)

kg/m^3

Table of theoretical fuel density for fuel IFUEL, 1 ≤ L ≤ 20. See RHOTEM for corresponding temperature values.

Used for IMETAL = 0. See RHOZNfor IMETAL > 0.

251-410

RHOTEM (L,IFUEL)

K

Temperature values for RHOTAB table, 1 ≤ L ≤ 20, for fuel IFUEL.

Note: If fuel solidus and liquidus temperatures are defined for fuel melting (see TFSOL and TFLIQ), then two adjacent entries for these temperatures should be provided in this table.

411-418

TMF (IFUEL)

K

Not to be input. It is set to fuel solidus temperature in the code. See TFSOL.

419

TR

K

Reference design point temperature. Temperature at which pin dimensions are measured. Suggested value: 300.

420-579

XKTAB (L,IFUEL)

W/m-K

Table of fuel thermal conductivity values for fuel IFUEL, 1 ≤ L ≤ 20. See XKTEM for corresponding temperature values.

If only XKTAB(1) is entered, property is temperature-independent.

(1 ≤ IFUEL ≤ IFUEL1)

580-599

XKTEM (L)

K

Temperature values for XKTAB table, 1 ≤ L ≤ 20.

600

FGMM

g/mol

Molecular weight of fission-gas atom. Suggested value: 131.

601

GATPF

Gas atoms generated per fission. Suggested value: 0.246.

602

ENPF

MeV

Energy per fission. Suggested value: 197.

603

RLEQ

Fraction of the as-fabricated porosity which defines the equiaxed / columnar fuel boundary. Suggested value: 0.6. PRSTY2 < RLEQ * PRSTY - columnar fuel PRSTY2 > RLEQ * PRSTY - equiaxed fuel

604

RUEQ

Grain size ratio at the equiaxed / as-fabricated boundary. Suggested value: 1.2. DGR2 < RUEQ * DGO - as-fabricated DGR2 ≥ RUEQ * DGO - equiaxed

605

PRSMIN

Minimum attainable porosity during restructuring. Suggested value: 0.02.

606-765

CPFTAB (L,IFUEL)

J/kg-K

Table of fuel specific heat values for fuel IFUEL, 1 ≤ L ≤ 20. See CPFTEM for corresponding temperature values.

If only CPFTAB(1) is entered, property is temperature-independent.

(1 ≤ IFUEL ≤ IFUEL1)

766-785

CPFTEM (L)

K

Temperature values for CPFTAB table, 1 ≤ L ≤ 20.

786-793

TFSOL (IFUEL)

K

Fuel solidus temperature.

794-801

TFLIQ (IFUEL)

K

Fuel liquidus temperature.

802-809

UFMELT (IFUEL)

J/kg

Fuel heat of fusion.

See also HFMELT.

810-812

TESOL (ICLAD)

K

Cladding solidus temperature.

813-815

TELIQ (ICLAD)

K

Cladding liquidus temperature.

816-818

UEMELT (ICLAD)

J/kg

Cladding heat of fusion.

819-878

CPCTAB (L,ICLAD)

J/kg-K

Table of clad specific heat values for clad ICLAD, 1 ≤ L ≤ 20. See CPCTEM for corresponding temperature values.

If only CPCTAB(1) is entered, property is temperature-independent.

(1 ≤ ICLAD ≤ ICLAD1)

879-898

CPCTEM (L)

K

Temperature values for CPCTAB table, 1 ≤ L ≤ 20.

899-901

TME (ICLAD)

K

Not to be input. Set to cladding solidus temperature in the code. See TESOL.

902-909

UMELT (IFUEL)

Not currently used.

910-969

YLDTAB (L,ICLAD)

Pa

Table of clad yield values for clad ICLAD, 1 ≤ L ≤ 20. See YLDTEM for corresponding temperature values.

If only YLDTAB(1) is entered, property is temperature-independent.

(1 ≤ ICLAD ≤ ICLAD1)

970-989

YLDTEM (L)

K

Temperatures values for YLDTAB table.

990-1049

CROETB (L,ICLAD)

J/m^3-K

Specific heat * density for cladding in table location L, 1 ≤ L ≤ 20. See CROETM for corresponding temperature values.

If only CROETB(1) is entered, property is temperature-independent.

1050-1069

CROETM (L)

K

Temperature values for CROETB table.

1070-1072

CE (ICLAD)

J/kg-K

Cladding specific heat at solidus temperature for CLAP cladding motion module. 1 ≤ ICLAD ≤ 3. Suggested value: 690.

1073-1080

PRSTY (IFUEL)

As-fabricated porosity for each fuel type. IFUEL ≤ 8.

1081

AC

Not currently used.

1082

QSWL

Not currently used.

1083

APORE

m^2-K^1.5/s

Pre-exponential factor in pore velocity.

VPORE = APORE * (dT/dr) * exp(-QPORE/(RGASSI * T)) / (T ** ABC)

Suggested value: 20.704.

1084

QPORE

J/gm-mole

Pore migration activation energy Suggested value: 4.5281E05.

1085

ABC

Exponent of temperature factor in pore velocity. Suggested value: 1.5.

1086

RGASSI

J/gm-mole-K

Ideal gas constant. Suggested value: 8.31434.

1087

GAMMA

J/m^2

Fuel surface tension. Suggested value: 0.45. See SUFU.

1088

APG

Pa

Pre-exponential factor in bubble radius parameterization. Suggested value: 5.0E04. | RB = (2 * GAMMA/APG) * exp (-QPG / (RGASSI * TEMP))

1089

QPG

J/mole

Temperature dependence of bubble radius. Suggested value: 5.65065E04.

1090

GK

m^3/s

Pre-exponential factor in unlimited grain growth rate. DG ** NGRAIN = DGO ** NGRAIN + GK * TIME * exp (- QV / (RGASSI * TEMP)) Suggested value: 1.717E10.

1091

QV

J/gm-mole

Activation energy of unlimited grain growth rate. Suggested value: 3.87E05.

1092

GK1

m^2/s

Pre-exponential factor in limited grain growth rate. (Ainscough et al. model). Suggested value: 1.45556E-08.

1093

QV1

J/mole-K

Temperature dependence in limited grain growth rate. Suggested value: 2.67E+5.

1094

GRAINK

m

Pre-exponential factor in maximum grain size. DMAX = GRAINK * exp(-GRAINQ / (RGASSI* TEMP))

1095

GRAINQ

J/gm-mole

Temperature dependence in maximum grain size. Suggested value: 6.3375E+04.

1096

CVXE

J/kg-K

Xenon specific heat at constant volume. Suggested value: 94.69.

1097

CVHE

J/kg-K

Helium specific heat at constant volume. Suggested value: 3.13E+03.

1098

ROFF

m

Surface roughness of fuel. Suggested value: 3.3E-06.

1099

ROFC

m

Surface roughness of inner cladding. Suggested value: 1.78E-06.

1100

AZEROX

Calibration factor in solid-solid conductance. Not currently used.

1101

GAMGS

Cp/Cv parameter in jump distance calculation. Suggested value: 1.66.

1102

HARDNS

Pa

Meyer’s hardness of the softer contacting surface in solid-solid gap conductance. This is set to 3 * yield stress within the code.

1103

ET

Exponent of the pressure dependence in solid-solid conductance. Suggested value: 1.

1104

ACCHE

Accommodation coefficient of helium. Suggested value: 0.15.

1105

ACCXE

Accommodation coefficient of xenon. Suggested value: 0.805.

1106

CZERO

Calibration constant for surface roughness in gap conductance calculation. Suggested value: 1.98.

1107

STEBOL

W/m^2-K^4

Stefan-Boltzmann constant. Suggested value: 5.67E-08.

1108

EMSF

Fuel emissivity. Suggested value: 0.9.

1109

EMSC

Cladding emissivity. Suggested value: 0.8.

1110

QA1

K

Parameter in Weisman fission-gas release model. Probability of escaping directly without being trapped, KPRIME = exp(-QA1/ TEMP - QA2 - QA3 * DEN) where DEN = percent of fuel theoretical density. Suggested value: 6.92E+3.

1111

QA2

Parameter in Weisman fission-gas release model. Suggested value: 33.95.

1112

QA3

Parameter in Weisman fission-gas release model. Suggested value: 0.338.

1113

QA4

K

Parameter in Weisman fission-gas release model. Probability of trapped fission-gas atom getting released from trap and then escaping per second, K = exp(-QA4/ TEMP - QA5). K is in units of 1/s. Suggested value: 1.48E+04.

1114

QA5

Parameter in Weisman fission-gas release model. Suggested value: 9.575.

1115

ALFSS

1/s

Pre-exponential factor in isotropic fission- gas release model. Fractional release rate= ALFSS * exp(-BETSS/TEMP). Suggested value: 2.0E-04.

1116

BETSS

K

Temperature dependence in isotropic fission-gas release model. Suggested value: 1.1E+04.

1117

CNU

Cladding Poisson ratio. Suggested value: 0.3.

1118

FNU

Fuel Poisson ratio. Suggested value: 0.3265.

1119

AM

Stress exponent in the fuel creep law for stress relaxation calculation. Strain rate = AONE * stress ** AM * exp(-QLAX/(RGASSI * Temp)). “AONE” is evaluated in the code depending on fractional fuel density and fuel grain size. Suggested value: 1.0.

1120

QLAX

J/mole

Activation energy for diffusion creep. Suggested value: 3.77E+05.

1121

QLAX2

Not currently used.

1122

DDX

Not currently used.

1123

DDX2

Not currently used.

1124

RGAS

Pa-m^3/kg-K

Gas constant per kilogram for fission-gas (as in PV = MRT). Suggested value: 65 for high burnups.

PLUTO2 AND LEVITATE Input (1125-1199, 1206-1217, 1229-1257)

1125

CINAF0

Fraction of the coolant flow area occupied by the liquid sodium film left behind by moving coolant slugs in PLUTO2. This is also the maximum value in the voided channel. CINAF0 must be < CIVOID. See WFS00 and WF0 to input consistent values. Suggested value: 0.15.

1126

CIBBIN

If the liquid fuel volume fraction in the channel is greater than CIBBIN, the fuel flow regime is treated as a bubbly flow regime. See VFNALQ and CIANIN.

1127

CIREFU

Reynolds number for annular or bubbly fuel flow above which the friction factor is assumed to be constant and equal to CIFRFU.

1128

CIFRFU

Moody friction factor for turbulent bubbly fuel flow (See CIREFU).

1129

CIFUMO

Fraction of the axial momentum of the fuel flow in the pin which is retained by the fuel which is ejected into the coolant channel.

1130

CIVOID

If the sodium void fraction in the coolant channel is less than CIVOID the heat-transfer and friction between sodium and cladding are based on single- phase correlations for the homogeneous mixture of the two phases of sodium. CIVOID must be > CINAF0 and < CIA4. For sodium void fractions greater than CIVOID see CIA4 and HCFFMI. See Table 14.4.1.

1131

CIA1

Constant in the fuel particle-to-sodium heat-transfer coefficient. H = CIA1*(conductivity of fuel)/(particle radius) * (1-Na void fraction) ** CIA2. (See Eq. (14.4-112) and Eq. (14.4-116)).

1132

CIA2

(See CIA1).

1133

CIA3

Constant in the molten fuel-to-cladding and molten fuel-to-solid fuel heat-transfer coefficient. Constant for oxide fuel but strongly dependent on Reynolds number for metal fuel. (See Eq. (14.2-36), Eq. (14.4-144), and Eq. (14.4-152)).

1134

CIA4

If the sodium void fraction is greater than CIA4, the heat-transfer coefficient between two-phase sodium and cladding, moving fuel and fuel crust is based on an interpolation. CIA4 must be > CIVOID. (See Eq. (14.4-103), Eq. (14.4-125) and Eq. (14.4-130) in the documentation).

1135

CIA5

Constant in the fuel particle-to-sodium / fission-gas drag which controls the dependence on the void fraction. (See Eq. (14.4-195) in the documentation). Suggested value: -1.7.

1136

CIA6

Constant in the bubbly fuel flow drag calculation (See Eq. (14.4-202)). Suggested value: 0.4272.

1137

CIFN

Not currently used.

1138

FNFUAN

Not currently used.

1139

CPFU

J/kg-K

Average specific heat of moving liquid or solid fuel.

1140

CDFU

J/m-s-K

Average thermal conductivity of moving liquid or solid fuel.

1141

CMNL

Pa^-1

Average compressibility of liquid sodium at roughly the sodium temperature at the time of pin failure in the vicinity of failure.

1142

CDNL

J/m-s-K

Average thermal conductivity of liquid sodium at roughly the sodium temperature at the time of pin failure in the vicinity of failure.

1143

CIETFU

Effectiveness of fuel particles to entrain or tear off a liquid sodium film. CIETFU = 1.0 means that the fuel acts as a gas with the gas density equal to the fuel smear density. For CIETFU = 0.1 only one tenth of the fuel density is used.

1144

CDVG

J/m-s-K

Average thermal conductivity of the sodium vapor / fission-gas mixture at temperatures roughly 200-300 K higher than the sodium temperature at the time of pin failure in the vicinity of failure. Used only in Dittus-Boetter correlation for Nusselt numbers. At present, use sodium vapor value.

1145

VIFI

kg/m-s

Average viscosity of fission-gas.

1146

CFNACN

J/m^2-s-K

Sodium condensation coefficient.

1147

CFNAEV

J/m^2-s-K

Sodium evaporation coefficient. Should be larger than the above condensation coefficient.

1148

FIFNGB

Fraction of the fission-gas entering the cavity with the melting-in fuel which is on grain boundaries. This fraction of the fission-gas becomes immediately available, whereas the remainder becomes available only after a coalescence time. Suggested value: 0.10. (See CIRTFS)

1149

VINL

kg/m-s

Average viscosity of liquid sodium at roughly the sodium temperature at the time of pin failure in the vicinity of failure.

1150

VIVG

kg/m-s

Average viscosity of the fission-gas/ sodium-vapor mixture. (For temperature range and other comments, see CDVG).

1151

EGFUSO

J/kg

Internal energy of fuel at the solidus point.

1152

DZPLIN

m

Minimum length of the edge cells in the interaction region of PLUTO-2 and LEVITATE. Values between 0.005 and 0.05 meter are allowed. DZPLIN has to be smaller than the shortest mesh cell in all channels. Recommended and default value: 0.02.

1153

CFCOFV

Condensation heat-transfer coefficient for fuel vapor. :units: J/m^2-s-K

1154

CFFURH

Not currently used.

1155

C1VIPR

A dimensionless constant in the artificial viscous pressure calculation inside the pin. (See Eq. (14.2-46))

1156

C2VIPR

A dimensionless constant in the artificial viscous pressure calculation inside the pin. (See Eq. (14.2-45))

1157

SUFU

J/m^2

Molten fuel surface tension. (See GAMMA)

1158

RAFPLA

m

Radius of initial fuel particles.

1159

RAFPSM

m

Radius of fuel particles after fragmentation, after TIFP s from initial injection.

1160

VFNALQ

Liquid sodium volume fraction in the coolant channels below which a continuous (annular or bubbly) fuel flow regime can be initiated (See CIBBIN, CIANIN, and EGMN used in determining fuel flow regimes).

1161

EGBBLY

J/kg

If the fuel flow regime is annular or bubbly, fuel freezing may be initiated when the fuel internal energy drops below EGBBLY. Its value should be above the solidus energy.

1162

VIFULQ

kg/m-s

Viscosity of the fuel above the fuel liquidus.

1163

VFNARE

Liquid sodium volume fraction above which a continuous fuel flow becomes a particulate flow again. Suggested value: >0.5. (See Figure 14.4.4)

1164

DTPLIN

s

Initial and minimum PLUTO2 and LEVITATE time step. Suggested value: 2.E-5. Minimum value: 1.E-6. Maximum value: 2.E-4.

1165

AXMX

m^2

Reference area for PLUTO2 and LEVITATE. This area times 1 meter is the volume to which all volume fractions in PLUTO2 or LEVITATE are referenced. It makes the volume fractions more meaningful if this area is equal to the area encompassing everything inside the outer perimeter of the subassembly wall (not per fuel-pin but per fuel subassembly).

1166

EPCH

Not currently used.

1167

TIPLMX

s

Time after PLUTO2 initiation when full PLUTO2 calculations are switched off and only the PLUTO2 energy equations are solved for all components which are then assumed to remain stagnant. Necessary for transient overpower calculations in which the lead channel fails many seconds before any other channel.

1168

DTPLP

s

Full PLUTO2 or LEVITATE printout every DTPLP seconds.

1169

FNMELT

Molten fuel is added to the cavity when it has gone through a fraction FNMELT of the heat of fusion. Suggested value: 0.9 (for TREAT experiment analysis lower values may be necessary).

1170

CIRTFS

1/s

Determines how fast dissolved fission-gas in the pin cavity coalesces and becomes free gas: Mass of fission-gas coalescing per unit time = CIRTFS * current mass of dissolved fission-gas in this node. Suggested value: 16.667.

1171

CISP

Not currently used.

1172

CIFUFZ

Controls the mode of fuel freezing in PLUTO2.

= 0, Conduction type freezing.

= 1, Bulk type freezing.

Allowed range between 0.0 to 1.0. Suggested value: 1.

1173

TIFP

s

Time delay for fragmentation of larger particles into smaller ones (relative to initial fuel injection time, see IPSIZE).

1174

CIANIN

Channel fuel (moving fuel + frozen fuel) volume fraction above which the whole perimeter of the channel is wetted by molten fuel in annular flow.

1175

TEFAIL

K

Cladding temperature of a node above which the cladding failure propagates to this node if the pin pressure is greater than the channel pressure + PRFAIL and also the areal fuel melt fraction greater than FNARME. Both cladding nodes must exceed this temperature. Relevant only if axial pin failure propagation is determined by input, if KFAILP = 1. Suggested value: Steel solidus temperature TESOL.

1176

FNARME

Relevant for both axial pin failure propagation options (KFAILP = 0 or 1). FARME is the minimum areal fuel melt fraction of a node above which a cladding failure can propagate into this node if additional conditions depending upon the value of KFAILP are satisfied.

1177

PRFAIL

Pa

Relevant only if KFAILP = 1. (See TEFAIL).

1178

EGMN

J/kg

The continuous fuel flow regimes cannot be initiated below this fuel internal energy. Its value should be above the solidus energy.

1179

HCFFMI

J/m^2-s-K

Convective heat-transfer coefficient from the surface of a frozen fuel crust to two-phase sodium/fission-gas mixture (liquid sodium in the form of dispersed drops) with a void fraction > CIVOID.

1180

HCFUBB

J/m^2-s-K

Convective heat-transfer coefficient between the interior of the molten fuel and two-phase sodium/fission gas mixture bubble surfaces in the bubbly flow regime.

1181

FNHTFU

Fraction of the convective heat-transfer coefficient between liquid fuel and cladding which remains effective when the moving fuel consists of solid chunks.

1182

XPL5

For future use in PLUTO2.

1183

XPL6

For future use in PLUTO2.

1184

TECLMN

K

Maximum outer cladding node temperature above which freezing fuel cannot stick to the cladding (the same input value limits the freezing on the inner structure node). (this is used in PLUTO2 only).

1185

TECLRL

K

Temperature of the middle cladding node above which plated-out fuel is released. (this is used in PLUTO2 only).

1186

CIHCFU

Dimensionless coefficient in the Deissler heat-transfer correlation for inpin fuel motion. Nu = CIHCFU*Pr*Re^0.8

1187

HCCLMI

J/m^2-s-K

Convective heat-transfer coefficient from hotter cladding to two-phase sodium/ fission-gas mixture (liquid sodium in the form of dispersed drops) with a void fraction > CIVOID.

1188

CMFU

Pa^-1

Average adiabatic compressibility of liquid fuel.

1189

XPL7

For future use in PLUTO2.

1190

XLP8

For future use in PLUTO2.

1191

XLP9

For future use in PLUTO2.

1192

XPL10

For future use in PLUTO2.

1193

XPL11

For future use in PLUTO2.

1194

XPL12

For future use in PLUTO2.

1195

CDCL

J/m-s-K

Average conductivity of the solid cladding.

1196

CPCL

J/kg-K

Average specific heat of the solid cladding.

1197

CPCLRH

J/m^3-K

Average specific heat times density of the solid cladding.

1198

RHSLBT

kg/m^3

Average physical density of the lower liquid sodium slug.

1199

RHSLTP

kg/m^3

Average physical density of the upper liquid sodium slug.

1200

COEFDL (1)

Not currently used.

1201

COEFDL (2)

1/K

Molten fuel volumetric thermal expansion coefficient, ALPHA2. (DEFORM uses with COEFDS(1)) Suggested value: 9.3E-5. Rho = COEFDS(1)/(1+COEFDL(2) *(T-273.15))

1202

QSTAR

Not currently used.

1203

ABCPU

Not currently used.

1204

QPU

Not currently used.

1205

DPUO

Not currently used.

1206

RHSSLQ

kg/m^3

Density of steel in the fuel crust. (See CPCL, CPCLRH, and RHSSSO). Suggested value: 6000.

1207

CIBBDI

Liquid fuel volume fraction above which the transition from annular to bubbly fuel flow regime occurs in disrupted regions (i.e., regions having no pin geometry). Suggested value: 0.2.

1208

CIANDI

Liquid fuel volume fraction above which the transition from partial perimeter annular to full perimeter fuel flow regime occurs in disrupted regions. Suggested value: 0.1.

1209

CIVIMT

The fuel viscosity at solidus is set equal to CIVIMT times the value at liquidus (See VIFULQ). The fuel viscosity between solidus and liquidus is evaluated by interpolation between these two values. Suggested value: 200.

1210

EGSESO

J/kg

Solidus energy of steel. Suggested value: 8.18E+5.

1211

EGSELQ

J/kg

Liquidus energy of steel. Suggested value: 1.076E+6.

1212

CPSE

J/kg-K

Specific heat of molten steel. (See CPCTAB, CE, CPCL, and CPCLRH). Suggested value: 768.

1213

FRMRSE

The fraction of latent heat of fusion to be satisfied for steel to be considered a moving fluid in LEVITATE. Suggested value: 0.5.

1214

FNSROS

Initial fraction of structure in the inner node (facing the channel). (See DSTIZ and DSTOZ for consistent input). Suggested value: 0.1 to 0.9.

1215

RHSSSO

kg/m^3

Density of solid steel. (See CPCL, CPCLRH and RHSSLQ). Suggested value: 6.95E+3.

1216

RGFV

J/kg-K

Gas constant for the fuel vapor. Suggested value: 31.

1217

RGSV

J/kg-K

Gas constant for the steel vapor. Suggested value: 145.

1218

TMIDFG

Not currently used.

1219

FGSPRD

Not currently used.

1220

FGPORX

Not currently used.

1221

WST

Not currently used.

1222

HECOND

Not currently used.

1223

FGCOND

Not currently used.

1224

AKCOND

Not currently used.

1225

HEMM

Molecular mass of helium atom. Suggested value: 4.

1226

EPSSFP

Per^a/o burn-up

Volume swelling fraction due to solid fission products. Suggested value: 3E-03.

1227

HEMASX

Not currently used.

1228

ZSWFAC

Not currently used.

1229

FNDISR

Ratio of molten cavity radius to fuel pellet radius needed for disrupting pins in LEVITATE. Pins can also disrupt if the outermost fuel node is above the solidus. (DTDISR must also be met).

1230

DTDISR

K

Fuel-pin disruption in LEVITATE is allowed if the cladding middle node temperature is greater than cladding solidus temperature minus DTDISR. (FNDISR must also be met). Not currently used.

1231

SRFMLE

If SRFMLE = 0.0, liquid sodium film on structure is thrown away in LEVITATE. If SRFMLE > 1.E-10, the sodium in the structure film is conserved. LEVITATE mixes the sodium film with the sodium vapor in the channel. This can lead to an excessive pressure event in the channel due to fuel/sodium interactions.

1232

XLE4

Not currently used.

1233

XLE5

Not currently used.

1234

XLE6

Not currently used.

1235

XLE7

Not currently used.

1236

XLE8

Not currently used.

1237

XLE9

Not currently used.

1238

XLE10

Not currently used.

1239

XLEPT1

Not currently used.

1240

XLEPT2

Not currently used.

1241

XLEPT3

Not currently used.

1242

XLEPT4

Not currently used.

1243

XLEPT5

Not currently used.

1244

XLEPT6

Not currently used.

1245

XLEPT7

Not currently used.

1246

XLEPT8

Not currently used.

1247

XLEPT9

Not currently used.

1248

PLUT1

Not currently used.

1249

PLUT2

Not currently used.

1250

PLUT3

Not currently used.

1251

PLUT4

Not currently used.

1252

PLUT5

Not currently used.

1253

PLUT6

Not currently used.

1254

PLUT7

Not currently used.

1255

PLUT8

Not currently used.

1256

PLUT9

Not currently used.

1257

PLUT10

Not currently used.

1258

FAXIAL

Fraction of calculated axial expansion to be actually used by DEFORM. Suggested value: 1. (See EXPCOF).

1259

FCLDWK

Initial cold-work strain of the cladding. (Required if IYLD = 1).

1260

FMELTD

Not currently used.

1261

FSTRAN

Not currently used.

1262

FTMPCH

Fraction of fuel or blanket melt temperature (TMF(IFUEL)) at which crack healing is assumed. (Required if IHEALC = 2).

1263

EXPCOF

Fraction of the axial expansion reactivity calculated by DEFORM to be used for feedback effects. (See FAXIAL). 0.0 ≤ EXPCOF ≤ 1.0. Suggested value: 1.0.

1264

PRTSTR

s

Time for the first transient printout if IPROPT = 1.

1265

PRTDEL

s

Time interval between printouts if IPROPT = 1.

1266

FIRLIM

Failure fraction at which the main time step is cut to DTFALL. For each fuel pin failure option a time-dependent fraction between 0.0 and 1.0 called failure fraction is defined for each fuel axial segment which indicates how close to pin failure the axial segment is at the current time. Failure fraction is 0.0 at the beginning of the transient, and equals 1.0 at the time of pin failure. (See MFAIL).

1267

SECLIM

Failure fraction at which the main time step is cut to DTFAL2.

1268

THRLIM

Failure fraction at which the main time step is cut to DTFAL3.

1269

DTFAL1

s

Main time step when FIRLIM ≤ failure fraction < SECLIM.

1270

DTFAL2

s

Main time step when SECLIM ≤ failure fraction < THRLIM.

1271

DTFAL3

s

Main step when THRLIM ≤ failure fraction < 1.0.

1272

AKD

Not currently used.

1273

CKD

Not currently used.

1274

QKD

Not currently used.

1275

FGFI

Mole fraction of fission gas in the initial fill-gas. (Assumed same molecular weight as FGMM).

1276

CIPINJ

Controls the ejection of molten fuel/ fission gas from the pin cavity when the mechanistic ejection model is not used. See INRAEJ. Suggested value: 2.5E4.

1277

DTPNIN

s

Initial and minimum PINACLE time step. Suggested value: 2.E-5.

1278

TIPNMX

s

PINACLE maximum time. Not currently used.

1279

DTPNP

s

Full PINACLE printout every DTPNP seconds.

1280

ASRALU

Aspect ratio of cylindrical chunks = 2R/L. Recommended value = 1.

1281

UN1281

Not currently used.

1282

UN1282

Not currently used.

1283

UN1283

Not currently used.

1284

RALUDI

Radius of chunks generated by pin disruption.

1285

RALUFZ

Radius of chunks generated by freezing and crust break-up. If set to zero the code provides default values based on local geometry. Recommended value: 0.

1286

CINAPN

= 0, All the sodium vapor pressure is added to the local pressure.

= 1, Only the excess of the sodium vapor pressure over the fission gas and fuel vapor pressure is added to the local pressure.

Note: This variable is relevant only if INAPN is equal to 1.

1287

CPCM

Chemical equilibrium coefficient of Pu at center-to-middle zone interface used in computing zone formation in U-Pu-Zr alloy fuel. Suggested value: 1.177.

1288

CPMO

Chemical equilibrium coefficient of Pu at center-to-outer zone interface used in computing zone formation in U-Pu-Zr alloy fuel. Suggested value: 1.0723.

1289

CZCM

Chemical equilibrium coefficient of Zr at center-to-middle zone interface. Suggested value: 9.79.

1290

CZMO

Chemical equilibrium coefficient of Zr at center-to-outer zone interface. Suggested value: 7.84.

1291

CUCM

Chemical equilibrium coefficient of U at center-to-middle zone interface. Suggested value: 0.448.

1292

CUMO

Chemical equilibrium coefficient of U at center-to-outer zone interface. Suggested value: 0.5866.

1293

EPSMS

kg

Criterion for zonal fuel mass convergence in computing zone formation in U-Pu-Zr alloy fuel. Suggested value: 1.0E-6

1294

EPSCOM

Criterion for the convergence of zonal weight fractions of Pu and Zr. Suggested value: 1.0E-3

1295

CIPNTP

Controls the calculation of the fuel pin top boundary temperature, which is important in triggering the axial in-pin fuel relocation.

= 0, Boundary temperature is equal to the temperature of the material in the node above the active fuel.

= 1, The boundary temperature is the same as the temperature of the central top node of the active fuel.

= 2, This option is available for metal fuel pins only. The in-pin fuel motion is triggered by a mechanistic model using 2-d temperature distributions for the top fuel node. (This option is not yet available.)

1296

ROGSPI

Mass of fission gas generated in the fuel pin per unit volume of the original pin and percent burnup. Used to set the fission gas arrays only if DEFORM is not used (ISSFUE = 0).

1297

PRSFTN

Partial pressure of dissolved gas, due to surface tension. This pressure is calculated as 2 x SIGMA/R. The recommended value for oxide fuel is 320 x 10**5 Pa. (SIGMA = 400 x 10^-3 N/m, R = 250 x 10**-10 m).

1298

COLFAC

Multiplier on the sodium density in the coolant reactivity calculation. Suggested value: 1.0.

1299

GAMGAS

Cp/Cv for pin plenum gas, P*V**GAMGAS = constant for adiabatic changes. Typical values: 1.3 - 1.6.

METAL FUEL PROPERTIES DATA

1300-1315

PUZRTP (L,IFUEL)

Metal fuel plutonium and zirconium weight fractions by fuel type (IFUEL). Used for IMETAL > 1. L=1, Plutonium weight fraction. L=2, Zirconium weight fraction.

1316-1323

RHOZN (IFUEL)

Metal fuel theoretical density at the reference temperature (TR) by fuel type (IFUEL). Used for IMETAL > 1. If RHOZN = -1.0, then it is internally evaluated based on the input composition (PUZRTP). If RHOZN = 0.0, then the fuel type IFUEL does not use the IFR Handbook-interpolated U-Pu-Zr alloy fuel properties of input option IFUELM = 0.

1324-1331

XLOGNA (IFUEL)

Metal fuel porosity fraction logged by bond sodium by fuel type (IFUEL). Used for IMETAL > 1.

1332

XSIGMC

To account for uncertainties in IFR handbook data for U-Pu-Zr and U-Zr alloy fuel heat capacity, add |XSIGMC| standard deviations (subtract if XSIGMC is negative) to the best estimate.

1333

XSIGMK

To account for uncertainties in IFR handbook data for U-Pu-Zr and U-Zr alloy fuel thermal conductivity, add |XSIGMK| standard deviations (subtract if XSIGMK is negative) to the best estimate. The standard deviation depends on fuel burnup (See BURNFU).

1334

XSIGMD

To account for uncertainties in IFR handbook data for U-Pu-Zr and U-Zr fuel theoretical density, add |XSIGMD| standard deviations (subtract if XSIGMD is negative) to the best estimate.

1335-1394

APROPI (I)

Coefficients for user-defined coolant properties.

APROPI(1:59) corresponds to the \(A_i\) defined in the coolant property equations of Section 12.13. APROPI(60) normally corresponds to the coolant critical temperature, \(T_c\). See Eq. (12.13-7).

1395-1725

DUMPMC

Not currently used.