We are thrilled to bring you a massive update focused on deepening the simulation realism of the RBMK reactor while introducing several highly requested quality-of-life features.
IMPORTANT: Please note that due to the significant changes in the physics engine and save logic, previous save files are not backward compatible. You will need to start a new game to experience the new features.
Neutronics: The core now runs on a 2-group neutron diffusion simulation. We’ve also implemented non-uniform fuel depletion and more consistent rod worth across the active zone.
Uniform Rod Worth: We have recalibrated the fuel depletion to ensure more uniform rod effectiveness across the active zone. This eliminates "dead zones" and ensures that reactivity changes are predictable and consistent throughout the full range of rod travel.
Rod Worth (Beff) before
Rod Worth (Beff) after
Realistic Core Behavior:
Implemented decay heat following a reactor SCRAM.
Added spontaneous subcritical fission based on fuel burnup.
Integrated Beta fractions (Beff) that adjust dynamically with average fuel burnup.
Thermal Hydraulics: Updated the positive void coefficient feedback to use water density rather than void fraction for higher accuracy. We’ve also added simplified logic for steam separators and feedwater systems.
Sensor Realism: Ion chambers now utilize real-world characteristics, including realistic signal "noise" when reaching their lower operable limits.
New Tools & Admin Controls:
Diagnostic Window (F3 key): A new overlay to monitor system health.
Admin Knobs (F5 key): Gain control over the simulation, including a PID controller for mass flow and an option to speed up Xenon effects.
Startup Manual:
You can download and follow startup manual based on real world RBMK startup procedure
Improvements
New reactor startup procedure to match real RBMK startup sequences
Added a new reactivity meter
Implemented spontaneous subcritical fission based on fuel burnup
Implemented decay heat following reactor shutdown
More uniform control rod worth distribution across the active zone
Ion chambers (probes) now use real-world characteristics and response curves
Ion chambers now exhibit noise when approaching their lower operational limit
ARM automatic regulation is operable at 8 MWt instead of 80 MWt
Reactor starts with AZ rods already withdrawn
AR starts in preffered configuration to avoid overwhelming new players
Added delayed neutron fractions (β-eff) based on average fuel burnup — higher burnup now correctly reduces β-eff
Added simplified steam separator and feedwater logic
Added a button to delete saves
Implemented 2-group neutron diffusion simulation
New games now start with proper non-uniform fuel depletion across the core
Thermal-hydraulic feedback now uses water density instead of void fraction to better replicate the positive void coefficient
Added a simple PID controller to regulate mass flow based on steam content (accessible via Admin Knobs)
Added an option to accelerate xenon transient effects (accessible via Admin Knobs)
Added ability to turn off tasks from settings
Added a new diagnostic window (F3)
Added Admin Knobs panel (F5)
Bug Fixes
Fixed lag spikes
Fixed cursor escaping the game window
Fixed ISS value indicator to correctly use a logarithmic scale
Fixed ISS probe readings to align with the startup procedure
Fixed neutron diffusion issues in empty fuel channels
Fixed period indicators (A) to correctly use a logarithmic scale
Fixed a bug when switching between AZS and AZS-R modes
Fixed AZS enabled state not being restored on load
Fixed AZMM enabled state not being restored on load
Fixed LAR corrector being incorrectly applied to LAZ imbalance calculations
Fixed adjusting one external AR probe inadvertently affecting readings on others
Fixed thermal power calculation using channel outlet instead of inlet for the lowest nodes
Fixed excessively large xenon poisoning effect
Fixed alarm volume being unadjustable through the settings menu
Fixed LAR setpoint not auto-adjusting while in ready state
Fixed LAR unacceptable imbalance signal failing to trigger
Fixed PK-UP indicator not lighting up only when all PK rods are fully withdrawn
Fixed issues with auto engaging AR in hot standby
Fixed LAR not re-engaging when loading a save
Fixed alarms triggering incorrectly on save load
New SKALA Codes
П0T0000 — displays water temperature in the steam separators