2.8.2.8. Block 14 — PRIMIN — Primary Loop Input Data

PX

1

Pa

Coolant exit pressure at ZPLENU.

PDEC

2

1/s

Pump head decay constant. (See PDEC1 and PDEC2).

PDEC1

3

1/s^2

Pump head decays as exp (-PDEC*t - PDEC1*t2 - PDEC2*t3).

PDEC2

4

1/s^3

Pump head decays as exp (-PDEC*t - PDEC1*t2 - PDEC2*t3).

PRETAB (L)

5-24

Normalized inlet coolant driving pressure or coolant flow rate table as a function of PRETME. Used only if IPRION ≠ 4. The inlet coolant driving pressure is the pressure difference between the subassembly inlet and outlet minus the gravity head across the subassembly. (See IFLOW).

PRETME (L)

25-44

s

Time for PRETAB table.

T0TAB (L)

45-64

K

Inlet temperature. (See NT0TAB).

T0TME (L)

65-84

s

Time for T0TAB table.

TNTRY

85

K

Re-entry temperature. Used only if PRIMAR-4 is not used.

DPGRV0

86

Pa

The primary loop gravity head. If 0.0, DPGRV0 is calculated at steady-state. Used only if IPRION ≠ 4.

ZPLENL

87

m

Reference elevation for the coolant inlet plenum.

ZPLENU

88

m

Reference elevation for the coolant outlet plenum.

ZIHX

89

m

Location of the thermal center of the intermediate heat exchanger. Used if IPRION ≠ 4 and DPGRV0 = 0.

DZBCGL

90

m

Minimum distance above subassembly exit for bubble breakaway. Suggested value: 0.1.

DZBCGU

91

m

Maximum distance above subassembly exit for bubble breakaway. Suggested value: 0.25. Note: When the top of the bubble is above DZBCGU or the bottom is above DZBCGL, the portion above DZBCGL is broken away.

TIMDBG

92

s

Time when PRIMAR1 debug prints start.

XMXMSI

93

kg

Coolant mass per pin in the mixing volume at the subassembly inlet.

XMXMSO

94

kg

Coolant mass per pin in the mixing volume at the subassembly outlet. If this quantity varies from channel to channel, then input the value for channel which boils first.

TIMMIX

95

s

Time constant for heat flow between inlet mixing volume and bulk inlet plenum temperature, also between outlet mixing volume and bulk outlet plenum temperature.

THT2VL

96

Minimum degree of implicitness for flow calculations in PRIMAR-4 and TSCNV1.

DUMPRI

97-150

Not currently used.

DEFAULT VALUES

XMXMSI = 0.002
XMXMSO = 0.002
TIMMIX = 1.00

Note: Variables marked P4 must be input when using PRIMAR-4. Other variables in this block are used for PRIMAR-1.