2.8.2.8. Block 14 — PRIMIN — Primary Loop Input Data

1

PX

Pa

Coolant exit pressure at ZPLENU.

2

PDEC

1/s

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

3

PDEC1

1/s^2

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

4

PDEC2

1/s^3

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

5-24

PRETAB (L)

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).

25-44

PRETME (L)

s

Time for PRETAB table.

45-64

T0TAB (L)

K

Inlet temperature. (See NT0TAB).

65-84

T0TME (L)

s

Time for T0TAB table.

85

TNTRY

K

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

86

DPGRV0

Pa

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

87

ZPLENL

m

Reference elevation for the coolant inlet plenum.

88

ZPLENU

m

Reference elevation for the coolant outlet plenum.

89

ZIHX

m

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

90

DZBCGL

m

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

91

DZBCGU

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.

92

TIMDBG

s

Time when PRIMAR1 debug prints start.

93

XMXMSI

kg

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

94

XMXMSO

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.

95

TIMMIX

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.

96

THT2VL

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

97-150

DUMPRI

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.