Rank the picture below the Core on the template slide Slide title 36pt Slide subtitle 18pt POLARIS, a Tool for Generating "Real" Thermal Margins in the Oyster Creek Simulator Alan Cheng and Robin Brown, Exelon Corporation Lotfi Belblidia, Studsvik Scandpower Power Plant Simulation Conference February 14-18, 2011 Tampa, Florida

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Core Monitoring Almost all BWRs and many PWRs use a core monitoring system in the plant control room. Core monitoring systems combine measured data and physics calculations to ensure compliance of fuel thermal limits as part of the Technical Specification requirements. These systems are frequently not available in the simulated control room or are available only via a simplified emulation. Short of providing a complete core monitoring system, POLARIS offers a way to implement a rigorous thermal limits monitoring system in the training simulator of the same quality and reliability as what is available to the operator in the actual control room. To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Overview All core monitoring start at the process computer, which collects measured plants signals. In BWRs, signals from the process computer include: –State point conditions: core thermal power, core coolant flow rate, feedwater temperature, recirculation flow and temperature, control rod positions, reactor pressure. –Fixed incore signals –Pressure indications, pump speeds These signals are used as inputs to a reactor physics computational module. The physics model is invoked manually or automatically, either on a fixed interval or in response to a change in plant condition. To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Benefits of Plant Core Monitoring Extend the amount of core information available to the operators and reactor engineers. Core Monitoring System acquires measured data from the plant computer and uses that data as input to core analysis software. Core analysis software provides 3D and scalar results as printed text or via a GUI. Extensions beyond the pure surveillance of Technical Specification limits include: –3D distributions (anything you want and more than you know what to do with) –Margin to limits (Power distribution, CPR, MAPLHGR, MAPRAT) –Heat balance –Reactivity balance To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Thermal Margins Monitoring on the Simulator Licensing authorities in many countries are requesting fidelity between the full scope training simulator control room and the actual control room, which may require the core monitoring system to replicate reference plant data. Exelon core test procedures includes comparison of power distributions and thermal margins Without implementing a complete core monitoring system, POLARIS provides a reliable way to fulfill the surveillance part of Technical Specification limits without the cost of a full- fledged core monitoring system. It uses “measured” data from the simulator and includes design code SIMULATE-3 as the core analysis software. To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Implementation in Oyster Creek (1) POLARIS requires the usual restart and library files used by S3R as well as an additional thermal margin library generated by SIMULATE-3 as part of the core depletion calculations. The following information is passed from the simulator to POLARIS: –Core power, flow, and inlet temperature –Control rod positions –LPRM signals –Xenon and samarium nodal concentrations This information is used to automatically generate a SIMULATE-3 input file. To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Implementation in Oyster Creek (2) A call to SIMULATE-3 is made on demand. After completion of the SIMULATE-3 calculation, all the thermal margins and data needed to generate a P1-like report are gathered. A P1-like report is generated and relevant information is passed to the simulated process computer for display to the operator (3DM Display). To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Example (Page 1 excerpt) PAGE 1 OYSTER CREEK CY-23 SEQUENCE NO 12 CORE PARAMETERS 3DM (POLARIS) 05-FEB :33 CALCULATED POWER MWT PERIODIC LOG 05-FEB :33 PRINTED POWER MWE AUTOMATIC CASE ID FMLD FLOW MLB/HR CALC RESULTS RESTART FMLD FLAPDR LPRM SHAPE - FULL CORE SUBC BTU/LB KEFF PR PSIa XE WORTH % LOAD LINE SUMMARY CORE MWD/ST XE/RATED CORE POWER 99.1% CYCLE MWD/ST AVE VF CORE FLOW 94.5% MCPR FLLLP LOAD LINE 102.9% CORRECTION FACTORS: MFLCPR= MFLPD= MAPRAT= OPTION: PRE_ARTS 4 LOOPS ON MANUAL FLOW MCPRLIM=1.658 MOST LIMITING LOCATIONS (NON-SYMMETRIC) MFLCPR LOC MFLPD LOC MAPRAT LOC PCRAT LOC …/… To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Example (Page 2 excerpt) PAGE 2 OYSTER CREEK CY-23 INSTRUMENT READINGS/STATUS SEQUENCE NO 12 CALIBRATED LPRM READINGS 05-FEB :33 CALCULATED 05-FEB :33 PRINTED 49D CASE ID FMLD C B LPRM SHAPE - FULL CORE A FAILED SENSORS 41D LPRM ( 0 SIGNALS FAILED) C B A D C 26.3 C B * A D C B A T = TIP RUN RECOMMENDED C = MFLCPR LOCATION 17D M = MAPRAT LOCATION C P = PCRAT LOCATION B D = MFLPD LOCATION A * = MULTIPLE LIMIT 09D C B A To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Example (Reactor Core State Display) To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt Summary There are two requirements for implementing POLARIS: –Up-to-date CASMO/SIMULATE core files –The use of a high fidelity simulator core model such as S3R Since POLARIS uses a well established design code (SIMULATE-3) for the calculation of thermal margins, there is no need for any assumption or simplification. The results from POLARIS can be presented with the same format as existing plant reports. Exelon is pushing to have site Reactor Engineers participate in licensed operator requalification simulator training. POLARIS will be a great aid in supporting this. To change footer – select Insert-Header Footer and make changes, then “Apply to all” POLARIS – “Real” Thermal Margins / Tampa, Florida – Feb 14-18, 2011

Slide title 36 pt Text 24 pt Bullets level 2 20 pt PROPRIETARY October Arizona title