The Nuclear Reactor Trainer

Cat.# SUR-001

For Windows



There are two versions of THE NUCLEAR REACTOR TRAINER software program, the BWR Trainer and the PWR Trainer.





The description given here applies to the BWR Trainer. The principal difference between the two models is that instead of voids, core flow control, a P-F Map, and IR scram, the PWR Trainer includes B-10 poison control and control by steam demand.
“The Nuclear Reactor Trainer” program is a dynamic and powerful educational tool for demonstrating and experiencing the realities and nuances of nuclear reactor behavior. Its versatility sparkles as it supports ClassRoom lessons extending from basic behavioral concepts to realistic operational transients. Selections from The Trainer can be molded to fit a wide variety of educational needs, including initial operator training, requalification training, Shift Technical Advisor training, and other advanced or specialized training.




The Nuclear Reactor Trainer Program assumes that the student user has a minimal introduction to the subject of reactor behavior - or to selected topics as appropriate to each module. Ideally this prerequisite knowledge would be acquired through ClassRoom teaching and demonstration by an Instructor, which would then be followed by student hands-on exercise. Those with previous training in reactor behavior, and especially with operational experience, should have little difficulty in using the program directly.

The Nuclear Reactor Trainer model employs point kinetics with six-delay groups, a non-fission neutron source, control rods with up to three reactivity rates and scram capability, a moderator temperature coefficient that may be either negative or positive, a doppler coefficient, a void coefficient, a selection of precursor yield fraction (beta), core flow control with a natural circulation component at low flow, and thermal characteristics associated with reactor power production and steam generation. The range of operation extends from shutdown to full power. The model operates in real or accelerated time and exhibits behavior that is representative of an actual BWR (Boiling Water Reactor).

It is also important to recognize what The Nuclear Reactor Trainer is not. It is not a self-contained educational device. The Trainer is not specific to a particular plant. There will be differences between it and any other plant. Nor is it intended to reproduce all features unique to a specific plant. The Trainer demonstrates many important basic concepts of reactor behavior that are common to BWR plants. Differences unique to your plant are then easily identifiable by the Instructor. And even though the model incorporates secondary steam control, this is not a training device that addresses the secondary plant. Rather, steam control is use to illustrate its effect on reactor behavior. The Nuclear Reactor Trainer is about reactor behavior, and that is all it is about.

The model addresses short term reactor behavior and does not incorporate xenon poison effects.
The Nuclear Reactor Trainer consists of six modules, three pertaining to basic concepts, namely Delayed Neutrons, Multiplication, and Reactor Rate, and three pertaining to real time behavior, namely Basic Transients, Graphics, and Control Panel. All modules have three subroutines, except for the delayed neutron module which has two and the real time graphics module which has four. The three subroutines of the real time modules are primarily designed to alter the initial conditions for a transient.

CONCEPTS
  • Delayed Neutrons
  • Multiplication
  • Reactor Rate

    REAL TIME
  • Basic Transients
  • Graphics
  • Control Panel

    The subroutine to be used is chosen from a Module Selection menu. The Graphics and Control Panel Modules make the transition from the graphic display, to the meter, and finally to the Control Panel. The Module subroutines are such that certain evolutions are better demonstrated on one than another. The specification sheet on each subroutine provides a detailed listing of suggested Exercises.

    The Nuclear Reactor Trainer incorporates many special features to provide flexibility.
    These include:
  • adjustable ramp reactivity rate; may be altered during transient
  • core flow control, with low flow natural circulation
  • negative, zero, and positive moderator coefficient; may be altered during transient
  • negative void coefficient
  • negative or zero doppler coefficient; usually set at start of transient
  • a selection of precursor yield fraction (beta) values, BOC to EOC
  • a random number generator sets the critical rod position for reactor startup
  • Intermediate Range switch with scram
  • Power-Flow Map
  • a time accelerator expedites ClassRoom demonstration by shortening the clock time required for extended evolutions
  • simultaneous display of graphics and meters allows for direct comparison of behavior, an effective means of transition from the ClassRoom graphic to the Control Room Panel
  • digital display of supplementary parameters
  • a printout option for hard copy of screen transient graphics
  • sample step-by-step Exercises are provided - the ultimate use of The Nuclear Reactor Trainer is limited only by the users imagination.

    The real time graphics are color coded such that the various parameters are in different colors to retain identity and the meter pointers are in corresponding colors to assist user monitoring of transients.

    TRAINER CONTROLS and PARAMETER SELECTION

    All controls for The Nuclear Reactor Trainer are on-screen displays located below the graphic.
    There are three basic controls, in frames, which are identified by red titles. These are rod controls, steam controls, and core flow controls. Parameter selections and other options are also located in this screen area. Certain controls and parameter selections are disabled under conditions where there use is not appropriate. When disabled, the frame title or control identification are blurred.

    Rod Controls
    Rod movement is continuous with time and not by notches.

    IN moves control rods at a specified reactivity rate toward the fully inserted position. The cursor must be moved to the Rods IN control button and the left mouse button pressed and held for the duration of rod movement. The rod move stops when the mouse button is released.

    OUT moves control rods at a specified reactivity rate out of the core. The cursor must be moved to the Rods OUT control button and the left mouse button pressed and held for the duration of rod movement. The rod move stops when the mouse button is released.

    SCRAM rapidly inserts rods to the fully inserted position, essentially a step change in reactivity. The cursor must be moved to the SCRAM control button and the left mouse button depressed for about 1 second to initiate scram.

    Steam Controls
    OFF sets steam flow to zero. Within preset limits this control can terminate the other two steam control settings. The cursor must be moved to the OFF control button and the left mouse button clicked. Without steam flow there are no voids in the core, the moderator temperature can increase with reactor power, and the moderator temperature coefficient is in effect.

    2% sets steam flow at a constant value of two percent of rated flow. This control is disabled below 250F, above 10% reactor power, and whenever the steam pressure control is activated. The cursor must be moved to the 2% control button and the left mouse button clicked. There are no voids in the core for this condition, the moderator temperature can change depending on the mismatch between reactor power and steam flow, and the moderator temperature coefficient is in effect.

    Pr Cont sets steam flow based on reactor power (actually the reactor vessel pressure). This control is available above 490°F and 0.1% power and below 3% reactor power with less than 2% voids. The cursor must be moved to the Pr Cont button and the left mouse button clicked. The percent steam flow and voids depend upon the reactor power and core flow. The moderator temperature is constant while this control is activated (saturation conditions exist).

    Core Flow (CF) Control
    INC increases core flow at a constant rate after an initial flow acceleration. The cursor must be moved to the INC control button and the left mouse button pressed and held for the duration of the core flow increase. The flow increase decelerates and stops after the mouse button is released.
    Minimum core flow is 27%. Core flow controls are inoperative when reactor power is less than 15%. Increasing reactor power from the POAH to 15% power using rod controls, creates a natural circulation contribution which increases core flow from 27% to 37% rated. Correspondingly, rod controls are inoperative such that reactor power cannot be reduced below 15% if core flow is greater than 37% rated.

    DEC decreases core flow at a constant rate after an initial flow acceleration. The cursor must be moved to the DEC control button and the left mouse button pressed and held for the duration of the core flow decrease. The flow decrease decelerates and stops after the mouse button is released. Flow control will not reduce core flow below 37% rated.

    Parameter Selection
    Rho-dot: option button for selection of rod reactivity rate, delta-rho/second, i.e reactivity rate for Rods IN and OUT control button. Rate change can be made at any time during transient. The default value is indicated by the active button (usually the top button).

    Critical Position: option button for selection of critical position. Control rod position is given in terms of “Control Rod Density” (CRD), which represents the percent of total rod insertion. For all rods fully inserted, CRD = 100%. For all rods fully withdrawn, CRD = 0%. The default critical position is indicated for the shutdown initial condition. Selection of RANDOM option button generates an unknown critical position for reactor startup. Random selection is only possible when control rods are fully inserted before rod movement. Once rods are moved or core flow is changed, this selection option is disabled. The option is also disabled for an initial condition of criticality.

    Beta: option button for selection of precursor yield fraction, beta. Selection possible at beginning of transient before rod move or core flow change. Thereafter, option is disabled. Default beta is 0.0065.

    Coefficients: option buttons allow change in moderator and doppler temperature coefficient of reactivity. Click to select value of each, individually. Coefficient change can be made at any time during transient. Units on Moderator coefficient are delta-rho/°F moderator. Units on Doppler coefficient are delta-rho/°F fuel.

    Temp: option for selection of temperature of reactor startup (one real time graphic and one control panel only). Default temperature is cold, 90°F, for Graphic shutdown subroutine, and 150°F for Control Panel shutdown subroutine. Selection of Hot option sets startup temperature at 500°F. Selection must occur before rod movement or core flow change.

    Other Options
    Demo tx2: accelerates time by factor-of-two for ClassRoom demonstration.
    Time acceleration must occur before rod move or core flow change, otherwise option is disabled. Default is real time. Click on check box to select accelerator.

    Digital: displays digital values for selected parameters, not the same parameters for all modules. The option may be selected or deselected at any time during transient. Click on check box to select the digital display. The digital reactivity display is disabled when a Random critical position is invoked. Also, the digital reactor period display indicates 999 seconds for an infinite period.
    Not all controls or parameter options are utilized (or appropriate) in every module but, with few exceptions, assignments are consistent between modules. The user need not memorize the controls and parameter assignments. These are shown across the lower portion of each screen display for ease of reference.
    The new student should not be intimidated by the number of controls and options available, rather he should understand that these are features to be implemented as his knowledge of the subject grows. For example, in the first few sessions the student needs little more than the IN and OUT Rod controls.

    EXAMPLE TRANSIENTS

    The following listing gives examples of transients that can be created and studied with The Nuclear Reactor Trainer .
  • demonstrate delayed neutron population fraction behavior during transient and steady state conditions
  • demonstrate single group precursor decay constant behavior during transient and steady state conditions
  • generate power curve from shutdown to full power
  • generate neutron source curve from shutdown to full power
  • generate curves demonstrating contribution of source strength and source multiplication from shutdown to full power
  • generate transient rate curves in Sub-Critical and Delayed-Critical regions
  • generate basic transients for step and ramp reactivity change in Sub-Critical region, in Delayed-Critical region < POAH, and in power range
  • perform reactor startup to POAH, identify attainment of criticality, and identify POAH
  • establish criticality in the Intermediate Range
  • change power level to new criticality, below POAH
  • perform heatup using reactor power
  • scram from criticality and allow power to decay to shutdown equilibrium
  • perform normal shutdown by inserting rod to full-in position and allow power to decay to shutdown equilibrium
  • initiate steam flow while slightly subcritical to create inadvertent criticality
  • use control rods and core flow for power ascension to 100%
  • use Power-Flow map for ascension exercise

    The operational transients listed, beginning with reactor startup, and many others can be performed using either the real time Graphic display or the Control Panel.


    PRICING

    The Nuclear Reactor Trainer(Windows)................................... U$ 495.00 + S&H
    Teaching Institution benefit of a preferential price)......... inquire
    Catalog. # SUR-001

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