2.8.2.14. Block 63 — PMATCH — Channel-Dependent Properties Input

1

TIMCNS

s

Time constant for fuel pin heat transfer. Default = 0.1.

2

AHBPAR

W/m^2-K\ \ \ m^2-K/W-m

If all three parameters are not equal to 0.0, the bond correlation is of the form:

HB = AHBPAR + 1.0/(BHBPAR +(gap size + CHBPAR)/HBPAR)

3

BHBPAR

see AHBPAR

4

CHBPAR

see AHBPAR

5

HBMAX

W/m^2-K

Maximum value of bond conductance when a gap exists; minimum value when a gap does not exist.

Default when AHBPAR, BHBPAR, and CHBPAR > 0.0:

HBMAX = AHBPAR

+ 1.0/(BHBPAR+CHBPAR/HBPAR)

6

HBMIN

W/m^2-K

Minimum value of bond conductance.

7

HBPAR

W/m-K

If all three parameters in AHBPAR, BHBPAR, and CHBPAR are zero, then the bond conductance equation when a gap exists is of the form: Bond conductance = HBPAR/gap.

8

HSNK

Should be set to 0.0.

9

TSNK

Should be set to 0.0.

10

DPRSTY

Not currently used.

11-17

XKSTIZ (KZ)

W/m-K

Inner structure thermal conductivity in zone KZ.

18-24

XKSTOZ (KZ)

W/m-K

Outer structure thermal conductivity in zone KZ.

25

DEL

W/m^2-K^4

Stefan-Boltzmann’s constant*emissivity. (See STEBOL, EMSF, and EMSC).

26

DGO

m

Initial grain size. Suggested value: 1.0E-05.

27

P0GAS

Pa

Initial plenum gas pressure at reference temperature TR.

28-34

XKRF (KZ)

W/m-K

Thermal conductivity of reflector for values of KZ not equal to KZPIN. XKRF(KZPIN) = thermal conductivity of cladding in the gas plenum region.

35

DENSS

Density of solid cladding at the reference temperature TR.

36

COOLDN

Not currently used.

37-43

RHOCSI (KZ)

J/m^3-K

Density * heat capacity for the inner structure.

44-50

RHOCSO (KZ)

J/m^3-K

Density * heat capacity for the outer structure.

51-57

RHOCR (KZ)

J/m^3-K

Density * heat capacity for the reflector. For KZ = KZPIN (the pin zone), RHOCR is for the cladding in the gas plenum.

58

RHOCG

J/m^3-K

Density * heat capacity for the gas in the gas plenum..

59

RG

m^2-K/W

Thermal resistance of plenum gas, typical value = 0.06.

60

FGMIN

Fraction of retained fission gas that assists non-equilibrium fission gas bubble induced fuel swelling (burnup dependent).

61

RST

Not currently used.

62

WRF

Not currently used.

63

RREF

Not currently used.

64

EMF

Not currently used.

65

EMS

Not currently used.

66

EMNA

Not currently used.

67

HMELT

Not currently used.

68

FCLOP

Fraction of open porosity that must be removed before axial movement allowed with metal fuels 0 ≤ FCLOP ≤ 1.

=0, Open porosity volume remains constant.

=1, All open porosity volume used before axial movement allowed.

69

TSEP1

K

Fuel plasticity temperature = TSEP1 + TSEP2 * (fuel-cladding interface pressure - plenum gas pressure). The fuel pellet annulus at this temperature does not move radially inward or outward during calculations of fuel mesh boundaries.

Suggested value: 2700 for oxide fuel.

70

TSEP2

K/Pa

Pressure adjustment to plasticity temperature.

Recommended value: 10^-8.

71

BONDNA

kg

Mass of sodium added to fuel pin to produce the fuel-cladding bond.

72

REFDEN

kg/m^3

Theoretical density of metal fuel at the reference temperature. Used for IFUELM = 2.

73

FUELEX

1/K

Fuel axial expansion coefficient. Used only with simple axial expansion feedback calculation. (See IAXEXP). Typical value: 1.1E-5.

74

CLADEX

1/K

Cladding axial expansion coefficient. Used only with simple axial expansion feedback calculation. (See IAXEXP). Typical value: 2E-5.

75

YFUEL

Pa

Fuel young’s modulus.

Typical value: 1.5E11.

Used with simple axial expansion and EBR-II feedback calculations.

76

YCLAD

Pa

Cladding Young’s modulus.

Typical value: 1.4E11.

Used with simple axial expansion and EBR-II feedback calculations.

77

FULREX

1/K

Fuel linear expansion coefficient for bond gap conductance calculation.

78

CLDREX

1/K

Cladding linear expansion coefficient for bond gap conductance calculation.

Note: FULREX and CLDREX are used only if ISSFU2 = -1 and IHGAP = 0.

79

EXPCFF

Effective axial expansion multiplier, for simple axial expansion feedback model only.

80

TTRANM

K

Transition temperature for determining the outer boundary of the middle fuel zone in the SSCOMP model for IFUELO = 1.

81

TTRANC

K

Transition temperature for determining the outer boundary of the central fuel zone in the SSCOMP model for IFUELO = 1.

82-89

HACHCH

Channel-to-channel (duct wall-to-duct wall) heat transfer coefficient x area per unit height. Used only if NCHCH > 0.

Note: Use the total duct wall contact area for all subassemblies involved.

90

POROSS

Porosity of the outer zone of metal fuel at the end of steady-state irradiation. Used in the SSCOMP model for IFUELO = 1. See also PORMSS and PORCSS.

91

PORMSS

Porosity of the middle zone of metal fuel at the end of steady-state irradiation. Used in the SSCOMP model for IFUELO = 1. See also POROSS and PORCSS.

92

PORCSS

Porosity of the central zone of metal fuel at the end of steady-state irradiation. Used in the SSCOMP model for IFUELO = 1. See also POROSS and PORMSS.

93-103

FPORNA

Ratio of sodium filled porosity to total porosity in the metal fuel by radial mesh node at the end of the pre-transient irradiation. Used in SSCOMP for IFUELO = 1.

104

TAUINV

1/s

Inverse of heat transfer time constant. Degree of implicitness, THETA2, is:

THETA2 = ( 1 + X )/( 2 + X )

X = DT * TAUINV

DT = time step size

Currently only used with the multiple pin option (JJMLTP not equal to 0).

Suggested value: 5.0 for metal fuel, 1.0 for oxide fuel.

FPIN-2 INPUT

105

XEUTHR

K

Eutectic threshold temperature (K).

Default value = 988.

(See FSPEC for consistent input).

106

XGBFRA

Not currently used.

107-130

XCLDHR (J)

Pre-transient hardness parameter used in cladding flow stress calculation. Default value is 0.223, the value appropriate to 20% CW un-irradiated stainless steel.

131

XFPLC0

Fuel power law creep constant C0.

132

XFPLC1

Fuel power law creep constant C1.

133

XFDVC0

Fuel power law swelling constant C0.

134

XFDVC1

Fuel power law swelling constant C1.

135

XCIPL0

Cladding idealized flow stress constant C0.

136

XCIPL1

Cladding idealized flow stress constant C1.

137

XHTERR

Relative convergence criterion for heat transfer calculation. Default value = 0.0005.

138

XEPSCA

Relative convergence criterion for cavity pressure. Default value = 0.001.

139

XEPSFE

Relative convergence criterion for finite element analysis. Default value = 0.0005.

140

XEPTES

Relative convergence criterion for plastic creep strains. Default value = 0.0005.

141

XEVTES

Relative convergence criterion for swelling strains. Default value = 0.0005.

END FPIN-2 INPUT

142

XMCFMC

Reserved by FED.

143

HACIFM

Reserved by FED.

144

HACOFM

Reserved by FED.

145

HAFMOP

Reserved by FED.

146

HAGPFM

Reserved by FED.

147

TOPLSS

Reserved by FED.

148

StructEX

1/K

Structure axial expansion coefficient. Used only with simple axial expansion feedback calculation. (See IAXEXP).

149

CDOSECONV

Conversion factor from clad fast neutron flux (n/cm²/s/1.0E+22) to dose rate (dpa/s).

Only applicable if IDEFOPT > 0 and ICTYPE = 4 (15-15Ti cladding).

150

COCOR

m

Clad outer corrosion thickness prior to transient initiation.

Only applicable if IDEFOPT > 0 and ICTYPE = 4 (15-15Ti cladding).

151

CDFMEAN

Mean value of the normal distribution, describing the predicted fraction of the fuel pins failed due to creep rupture as a function of Common Logarithm of CDF.

Only applicable if IDEFOPT > 0 and ICTYPE = 4 (15-15Ti cladding).

152

CDFSIGMA

Standard deviation value of the normal distribution describing the predicted fraction of the fuel pins failed due to creep rupture as a function of common logarithm of CDF.

Only applicable if IDEFOPT > 0 and ICTYPE = 4 (15-15Ti cladding).

153-200

DUMPCH

Not currently used.