NESC0710 HAMOC
HAMOC, Pressure Transients in Reactor Vessel Piping System after Accidents
NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES
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| Program name | Package id | Status | Status date |
|---|---|---|---|
| HAMOC | NESC0710/01 | Tested | 01-DEC-1978 |
Machines used:
| Package ID | Orig. computer | Test computer |
|---|---|---|
| NESC0710/01 | CDC 7600 | CDC 7600 |
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3. DESCRIPTION OF PROBLEM OR FUNCTION
HAMOC determines the pressure
transients in piping systems attached to a reactor vessel which
has been perturbed, by a hypothetical core disruptive accident
(HCDA) for example. The continuity and momentum equations are
solved. The energy equation is not programmed, but simplified
column separation logic is included to treat vapor pressures below
saturation. This simplified approach has been checked against
experimental data. HAMOC was written specifically for problems in
which forcing pressures are known as a function of time at certain
end boundary conditions, rather than as a general purpose code for
the solution of pump coastdown or valve closing problems.
HAMOC determines the pressure
transients in piping systems attached to a reactor vessel which
has been perturbed, by a hypothetical core disruptive accident
(HCDA) for example. The continuity and momentum equations are
solved. The energy equation is not programmed, but simplified
column separation logic is included to treat vapor pressures below
saturation. This simplified approach has been checked against
experimental data. HAMOC was written specifically for problems in
which forcing pressures are known as a function of time at certain
end boundary conditions, rather than as a general purpose code for
the solution of pump coastdown or valve closing problems.
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4. METHOD OF SOLUTION
The differential equations of continuity and
momentum are solved by the method of characteristics. When column
separation occurs, special internal boundary conditions are
temporarily established which fix the pressure at the saturated
vapor pressure during the existence of the cavity. Special
equations give the pressure rise when the cavity collapses.
The differential equations of continuity and
momentum are solved by the method of characteristics. When column
separation occurs, special internal boundary conditions are
temporarily established which fix the pressure at the saturated
vapor pressure during the existence of the cavity. Special
equations give the pressure rise when the cavity collapses.
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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM
The program
currently provides for maxima of:
56 legs
50 nodes per leg
15 three-way junctions
50 plots
1000 points per plot
1 line per plot
The fluid properties are those for sodium, and the pipe properties
are those for Type 304 stainless steel. The above restrictions
should not be difficult to alter; the following restrictions are
more stringent. There may be 1 or 2 pipe ends with prescribed
pressure-time history. All pumps have the same set of
characteristics. Fluid temperatures must be constant with time,
must be the same for all points within a leg, and must be the same
for all connecting legs at a pump, at a tee, or at a Y-junction.
The minimum leg length must not be smaller than
(time-step)*(pressure-pulse-speed + fluid-velocity).
The program
currently provides for maxima of:
56 legs
50 nodes per leg
15 three-way junctions
50 plots
1000 points per plot
1 line per plot
The fluid properties are those for sodium, and the pipe properties
are those for Type 304 stainless steel. The above restrictions
should not be difficult to alter; the following restrictions are
more stringent. There may be 1 or 2 pipe ends with prescribed
pressure-time history. All pumps have the same set of
characteristics. Fluid temperatures must be constant with time,
must be the same for all points within a leg, and must be the same
for all connecting legs at a pump, at a tee, or at a Y-junction.
The minimum leg length must not be smaller than
(time-step)*(pressure-pulse-speed + fluid-velocity).
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6. TYPICAL RUNNING TIME
The 45-leg sample problem requires about
110 seconds (CYBER74-18) or 21 seconds (CDC7600) execution time
for a run of 0.1 seconds real time. Typically, execution time on
the CYBER74-18 is about 0.00057 second per mesh-point per time
plane. Running times can be reduced significantly, with little
loss of accuracy, by using a constant friction factor.
The 45-leg sample problem requires about
110 seconds (CYBER74-18) or 21 seconds (CDC7600) execution time
for a run of 0.1 seconds real time. Typically, execution time on
the CYBER74-18 is about 0.00057 second per mesh-point per time
plane. Running times can be reduced significantly, with little
loss of accuracy, by using a constant friction factor.
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NESC0710/01
| File name | File description | Records |
|---|---|---|
| NESC0710_01.001 | INFORMATION | 2 |
| NESC0710_01.002 | SOURCE PROGRAM (F4) | 2189 |
| NESC0710_01.003 | JCL | 5 |
| NESC0710_01.004 | SAMPLE PROBLEM INPUT DATA | 70 |
| NESC0710_01.005 | SAMPLE PROBLEM PRINTED OUTPUT | 5583 |
Keywords: liquid metals, pressure, reactor safety, transients.