Summary
M32kx is a development of the M32 computer program which simulates the three-dimensional two-energy-group time-dependent response of nuclear reactor plant to control rod movement or alteration of coolant flow rate or power demand in external circuits. The program is primarily intended for the education and training of aspiring performance and safety engineers and students, and rapidly allows them to appreciate the qualities of different reactor concepts, designs, operating conditions and fault sequences. The program runs under Windows, from XP to Ten.
The program offers the following features:
a) it can model the physics and thermal behaviour of pin, plate or ventilated solid cores cooled by He, CO2, or water (liquid or two-phase);
b) the nuclear data are taken to be functions of fuel and/or moderator thermal properties;
c) coolant flow through the core can follow a single or multi-pass path, with optional flowrate zoning and streaming in and between every pass;
d) the program can represent one or two external loops, each loop including a lumped boiler model;
e) depending on user requirements, the initial steady state calculation can determine critical eigenvalue, critical rod height, or subcritical power;
f) the user can introduce transients by moving control rods, or by altering flow rate or power demand in the external loop(s);
g) the program indicates changes in core reactivity, power level, power distribution and circuit volume surge as a result of the user imposed transients;
h) the 'output' consists of on-screen tables and graphs showing the prevailing power distributions, temperature profiles, or the history of key parameters;
i) by using an 'accelerator', which trades accuracy for speed of execution, run times for educationally useful applications can approach real time.
The program covers Xenon transients, but it doesn't address fuel depletion or coolant boronation, Further, the program is not appropriate for safety analyses because it doesn't cover 'hot channels', fluid dynamics or system pressure transients.
Because of its graphics capability (for some examples, click on https://picasaweb.google.com/112966369932927955007/M32demo03?authkey=Gv1sRgCJmqkcCJweaXnAE# ) the program is expected to be helpful for:
a) the education and training of those involved with nuclear power, particularly students, operators, performance and safety engineers, and reactor physics specialists;
b) the preliminary assessment of situations where core power distribution may change significantly during transients - eg rod withdrawal faults, faults leading to substantial two-phase flow, or where there are asymmetric variations in core temperature profile arising from unequal changes in power demand or flow rate in external circuits;
c) the development of yet more comprehensive reactor performance computer programs suitable for safety analyses.
The program is offered in good faith but with no warranty as to fitness for purpose. Although it is offered with no formal validation, it is based on standard equations and its results are similar to those from more sophisticated calculations where comparisons have been made. No liability will be accepted for consequential damage or loss arising from its use.
For further information, please contact John Moorby through email: M32code@gmail.com
Updated October 2020
About the author:
John Moorby was employed by Rolls-Royce & Associates (RR&A) working on the Naval Nuclear Propulsion Program from 1962 until 1975. For much of that time he specialised in reactor plant transient models, calculations and safety analyses. The work involved reactor physics, fluid dynamics and heat transfer. His final year at RR&A was as Research Reactor Manager and Chairman of the Reactor Safety Committee.
John then moved to the South Western Region of the Central Electricity Generating Board (CEGB) where he became Head of Nuclear in the Scientific Services Department. The job covered a range of disciplines including nuclear safety, performance, environmental impact, reactor inspection, and economics.
In 1993, following the privatisation of the CEGB, John joined a Danish wind turbine company prospecting for and setting up wind farms. The wind farm at Parc Cynog, South Wales, is an example of that work.
He returned to the nuclear industry in 1997 to undertake Independent Peer Reviews of safety cases and validation reports. It was about this time that he recognised the need for a computer model of reactor plant that would be significantly more informative than a 'back-of-the-envelope' calculation, but easy to set up and simple to run - unlike the full blown computer programs used to justify nuclear performance and safety. Such a model would not only provide a 'sanity check' of results from the more elaborate programs but would also allow younger engineers to appreciate the complexities of nuclear plant which cannot be reflected in simple point kinetics models. The model could also be used by more experienced engineers to scope new situations quickly and easily. As a result, in about 2000 he wrote an early version of the program which has subsequently developed into the current version, M32kx. The program is actively used in the nuclear industry.