MNRSIM: A Research and Training Model of the McMaster Nuclear Reactor

BUGS!

• MNRSIM is built using very basic physical models, and many of these models have not yet been verified. Anyone who can supply concrete data which describes the actual behavior of light water type reactors is encouraged to submit testing scenarios.
• Water neither freezes nor boils in the model.
• Although water flow can be reversed in the core, heat transport is coded for one direction only.
• Many controls are present but inactive on each of the control panels, inactive controls are planned features which are currently either not working correctly, or not implemented at all.

• The power control is over simplified and not realistic.
• The calibration lock state sometimes does not save correctly.
• Calibration is confusing, and too complicated.
• The control rod positions should lock when the simulation is running.

• Energy Group settings for the core display and plot sometimes do not indicate the group being displayed.
• Table view also has same indication problem.
• Defined cells MUST have 4 character names. This limitation should be fixed.
• Cannot destroy the plot or core display window with standard windows close button.
• Core orientation is not indicated in any way.
• Core is not labeled in the same way as the MNR core. For example, MNR core uses Letters for one axis, numbers for the other.

• Red blinking light indicates the detection (and partial correction) of numerical errors in the heat transport method. The correction is a fudge, and a better numerical integration method should be installed.
• The HC Iter window shows which module is currently active. Normally this label should flicker quickly between each module, HC= Hardy Cross, HTP=Heat Transport, HTF=Core Heat Transfer. If it gets stuck on a single setting, the simulation is probably spending too much time in that module.
• The core heat transfer module sometimes exhibits odd behaviour, for example the initialization flag is often locked, but not always, core elements can be selected when time=0, but not at other times. The fuel plate selector doesn't always seem to be doing anything (although it is). The Z axis selector is sometimes left at 1, which produces a flat temperature distribution in the plate since this is the first plate. The module does work, although it isn't 100% intuitive how it works.

• The air temperature is currently used as the lowest temperature in the simulation for error detection. If the air temperature is set higher than the default temperature (20 deg C.) bad things will happen. If the air temperature is set lower than 0, pipes may spontaneously freeze. Fixing the heat transport model will remove this limiation.