PCTRAN Component Models
PCTRAN is a simulation program that incorporates knowledge
of reactor physics, thermal hydraulics, control system, etc.
into solution techniques with assistance of modern computer graphics
to operate interactively on a PC. The source code is in FORTRAN.
It is a product of twelve years of development. Extensive verification
had been conducted against Final Safety Analysis Reports, and
validated with respect to real plant data and other computer
analyses such as RETRAN, RELAP5, TRAC, MAAP, SAFE, etc.. They
were documented by over a dozen published papers in professional
journals. Reprints are available upon request.
PCTRAN is under a continuous upgrading and enhancement program
so that new features will be incorporated into the package periodically.
Currently it has the following component models:
- Thermal Hydraulics Model
- Lumped-loop approach with two-phase critical flow discharge,
non-equilibrium pressurizer for PWR and drift flux model for
BWR.
- Core Kinetics Model
- Point kinetics model with rod control and reactivity feedback
from moderator temperature, Doppler and voids.
- Control System
- PWR's rod, pressurizer pressure and level, steam generator
feedwater, turbine header pressure and steam dump control are
modelled to operate either in "AUTO" or "MANUAL"
mode following the unit load demand; BWR's rod, recirculation
flow and feedwater system are controlled to reach the same goal.
- Containment Model
- Containment's structure, cooler, spray, vent, etc. are modelled
to keep track of post-LOCA conditions.
- Severe Accident Model
- For an exposed core, the fuel clad may be overheated and
fission products may be released into the reactor coolant and
containment. They may be further released into the ambient atmosphere
depending upon the open pathways. Radioactive isotope types and
their release pattern are generated as source terms for offsite
dose estimate. For clad temperature beyond 1000âC, metal-water
reactions will generate hydrogen. The containment hydrogen concentration
will be calculated and its combustibility will be checked throughout
the transient.
Upon a client's specific order for the most-extensive severe
accident simulator, MST will prepare one that could include simulation
of the plant's radiation monitoring system (RMS). This could
be used as a tool for the plant's Severe Accident Management
program. Normal and accident readings for all area, effluent,
and process monitors throughout the plant will be calculated
and source terms for offsite release will be projected. These
could be used as input to the plant's dose dispersion model for
offsite dose distribution estimate. The system will then be an
integral part for the plant's emergency response plan.
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