ICCM Remote Display Replacement Project

Duke EnergyOconee Nuclear Station

Inadequate Core Cooling Monitoring SystemInstalled at the behest of the NRC following the 1979 TMI-2 accidentArchitecture• Two Independent Safety Trains• Main Cabinet I/O and processing• Remote Display Unit

Functions• RVLIS – Reactor Vessel Level Indication System• HLLMS – Hot Leg Level Monitoring System• CET – EQ Core Exit Thermocouples• HLT – WR Hot Leg Temperature RTD• WR RCS Pressure• Subcooled Margin

(cont. Functions)• Reg. Guide 1.97 parameters upgraded from non-QA instruments• Pressurizer Level – Temp and Press compensated

• 2 channels Train A• 1 channel Train B

• Pressurizer Temperature• Low Pressure Injection Flow• High Pressure Injection Flow• Borated Water Storage Tank Level• Reactor Building Spray Flow• Upper Surge Tank Level (secondary side inventory)• Steam Pressure SG A and B

Simulation

• Originally employed ICCM vendor supplied remote display hardware• Plasma display and electronic controller package

• 480 x 320 pixels bright orange• ~ 9 inch diagonal size• Characters 5x7 pixel

• Simulator generated the serial data stream from internal data• Custom interface application• RS 485 serial interface, 9600 baud• Discovered that checksum didn’t matter as long as something filled the space

OAC Interface

• Operator Aid Computer interface serial data stream• Same data stream as the RDU on separate cable• Serial interface card in the ICCM came with two channels – one was employed

by design to the RDU• ICCM data stream internally jumpered to create two streams

• The original system design was for D/A and A/D conversion to the OAC, so the ICCM system now has a bunch of stranded analog outputs• Hardware maintained to prevent system level errors

Data Quality

• Our first simulation did not address data quirks• Standard IEEE-754 data resolution and accuracy

• Bit resolution of inputs are noticeable• Flow• RCS leakage calculation

• Flow inputs low flow cutoff function was done outside of RVLIS model• Loss of power response distributed across simulation• Mixed results on LOP fidelity – OAC problematic

Simulator Bravo

• Circa 2008 Oconee added a second simulator• Unit 1 reference• Identical model to Sim Alpha w/ minor variation in I/O assignment

• Remote Display Hardware Not Available• Anywhere at any price

• Created the Simulator Remote Display Project

2008 Remote Display Project• Visual Basic 6• Duplicate all of the ICCM Remote Display Screens• Employ 2 - 14” LCD Monitors• Single PC for both display trains

• Modified data stream to include special Simulator Commands• Freeze (trend data updates)• Display Blank (loss of power)• Display Data Link Failure (default loss of data stream display)• Power Up Splash Screen• TCP/IP over Ethernet in lieu of RS-485

• OAC data untouched

2008 Remote Display Project• OTS 14” LCD monitors had to be modified• Front bezel removed to bring the screen closer to the front• Bezel removed to allow close mounting together• Monitor control buttons relocated to rear / taped• Screens masked to emulate 9” plasma display• Fonts close but not identical

• ICCM Page Display Control buttons on control board connected to PC through USB/ control switch interface box• Remote Display Functions were external to simulation just like

original RDU

2018 Oconee Simulator Rehost Project

• 2018 completed Rehost of the Oconee simulation to L3 OrchidMEplatform (upgrade from CAE-ROSE / custom EAI FORTRAN code)• ICCM Remote Display untouched in Rehost Conversion• Oconee Long Term plan is to retire all obsolete and unsupported

applications• VB6 targeted for generic replacement• RDU Host PC running Windows 7

2019 ICCM Module Update

Early 2019 Oconee rewrote the ICCM application (FORTRAN)

• Need driven by loss of power response on OAC• Data freeze on LOP• ‘Old’ status for points not updated

• Prior to this Reg. Guide 1.97 functions were not tightly integrated – they were scattered about in the original code – legacy issues from original EAI simulator• Two-second sample period for all ICCM functions (8086 uP technology)• Consolidation of all Reg. Guide 1.97 functions

ICCM Module Update (cont.)

• Integration of annunciator and other control function outputs• ICCM ‘analog’ outputs

• CB meters• Recorders• Integrated Control System

• Duplicates data character of ICCM hardware• RTD ~ 1200 counts• Thermocouple ~1600 counts• Milli-amp inputs ~ 1550 counts• CET reference junction RTD ~ 2600 counts• Square root flow function exhibits low flow cutoff and bit noise• Data looks like floating point but only certain values are possible

2019 Remote Display Project• OrchidME built-in graphics capability good fit for ICCM Remote

Display Unit• Project approved September 2019• Graphic application delivered December 2019• Application maintains system architecture of separate RDU from ICCM

cabinet functions• New 11 inch LCD display employed without modification

• Thin flat bezel• Control buttons on back of monitor

• New Dell 7060 mini-PC w/ dual display driver running Win 10

2019 Remote Display Project (cont.)

• ICCM RDU Control Buttons wired into Simulator I/O• RDU function is integral to OrchidME simulation• ICCM RDU screens now active for all simulators:• Sim Alpha and Sim Bravo• Development machines (6)• Glass-Top Simulators (4)• ICS Part Task Simulator

• OAC data driver moved to OrchidME schematics from legacy FORTRAN code (standard method)

Q&A