Westinghouse Nuclear Automation. Ovation -based Rod Control Logic Cabinet

Transcription

1 Westinghuse Nuclear Autmatin Ovatin -based Rd Cntrl Lgic Cabinet

2 Backgrund The Westinghuse slid state rd cntrl system has been in peratin at many plants fr ver 30 years. The riginal system has demnstrated its reliability but lacks built-in redundancies and has limited diagnstics. One f the cmplex elements in the system is the lgic cabinet that riginates all the system mdes, rd grup selectins, bank verlaps and system sequential timing. The lgic cabinet cmprises f 73 printed circuit bard lgic cards fr a furlp plant that cnsists f 23 bard types with numerus single- pint vulnerabilities (SPVs). Maintaining this system has becme mre challenging when the lgic cabinet SPVs, an aging wrk frce and diminished experience in the plants is cnsidered. System Descriptin Westinghuse has develped a cst-effective retrfit slutin t upgrade the rd cntrl system in a phased manner where the Lgic Cabinet is replaced and interfaces with the existing Pwer Cabinets, r the Lgic Cabinet and the Pwer Cabinets are upgraded simultaneusly. Fr the rd cntrl lgic cabinet upgrade, the existing cabinet electrnics are replaced with an Ovatin redundant cntrller panel assembly. This mdificatin is straightfrward and des nt interfere with r disturb the existing system signal cable interfaces. The lgic cabinet upgrade is implemented by remving the existing electrnic assemblies and installing a new panel cntaining the Ovatin upgrade equipment. The new panel, as shwn in the Figure 1 frnt view, cntains: a redundant cntrller, tw branches f input/utput (I/O), terminatin mdules, netwrk interfaces, temperature/humidity sensr, bus bar and line filter assemblies. The panel rear view in Figure 2 cntains redundant pwer supplies fr 24-VDC internal and field pwering, tw branches f I/O, terminatin mdules, bus bar and AC line filter assemblies. With this upgrade, the Ovatin I/O layut is designed t interface seamlessly with the existing field and pwer cabinet signals as shwn in Figure 8. Pre-manufactured cable assemblies will be prvided t wire the Ovatin I/O mdules t the existing cabinet terminal blcks. Existing lgic cabinet t pwer cabinet wiring and field signal wiring t the lgic cabinet will nt be disturbed. Lgic cabinet cnfiguratin cntrls such as the bank verlap thumbwheel switches, and reset and master cycler pushbuttns, are replaced with adjustable sftware based set-pints r cntrls. Additinally, Manual Cntrl Bank speed, Shutdwn Bank speed, Bank D full ut psitin and Bank D Withdrawal Limit (C11 Permissive) are prvided as sft cntrl adjustable set-pints. Implementing the manual speeds as set-pints eliminates the need fr NRS card in the 7300 prcess cntrl system. With this upgrade, the P/A cnverter functin and related hardware will be eliminated and replaced with Ovatin analg utput signals frm the lgic cabinet. Optinally, hardwired pulsed bank demand psitins (cntact utputs) t the plant cmputer can be replaced with prcess pints n the Ovatin highway transmitted t the plant cmputer. Main Cntrl Rm A new LCD tuch screen r muse-driven display will be prvided and lcated apprpriately in the main cntrl rm (MCR). Sft cntrl applicatin and mnitring graphic displays (Figures 4 thrugh 7) will be prvided as a backup indicatin t the Main Cntrl Bard (MCB) hard cntrls and cunters. The new applicatin display infrmatin and Ovatin alarm system infrmatin make the status and health f the rd cntrl system readily available t the peratr. With this upgrade, diagnsis f system prblems becmes straightfrward and minimizes trubleshting and maintenance effrts. The existing MCB mechanical step cunters will be replaced with the digital step cunters (Figure 3), that include audible clicking fr each pulse up- r dwn-cunt. There is ne step cunter fr each f the rd grups. The grup rd step cunters are munted in the existing step cunter husings n the MCB. The replacement step cunters in the cntrl rm are pwered by redundant 24 VDC the standard interface vltage fr the Ovatin I/O mdules. The existing (100 VDC) rd-in and rd-ut lamps will be replaced with 24 VDC LED units. The MCB speed indicatr is driven by the rd cntrl system ver the existing field cables. 1

3 Figure 1: Frnt view, Rd Cntrl Lgic Cabinet up-graded with Ovatin cntrller panel assembly Figure 2: Rear view, Rd Cntrl Lgic Cabinet up-graded with Ovatin cntrller panel assembly 2

4 Figure 3: Replacement Rd step cunter Step cunter display Figure 4: Rd Cntrl verview mnitring and status display 3

5 Figure 5: Rd Cntrl alarm status with sft reset pushbuttn Figure 6: Rd Cntrl maintenance display with sft set pint adjustment interfaces 4

6 Figure 7: Startup and grup cunter adjustment sft cntrls Figure 8: Ovatin I/O interfaces t field and pwer cabinets 5

7 Ovatin Lgic Cabinet Upgrade: Base System When an existing Ovatin infrastructure is already installed in the plant, the Westinghuse base scpe lgic cabinet upgrade cnsists f ne new redundant Ovatin cntrller panel assembly, redundant pwer supplies and sufficient I/O t address the existing field interfaces and number f pwer cabinets. In additin, munting hardware, interface cables and new grup rd step cunters are prvided. Typical dcumentatin included are as fllws: System Design Specificatin Standard Factry Acceptance Prcedure Standard Site Acceptance Prcedure Electrmagnetic Interference/Radi-frequency Interference Test Reprt Failure Mdes and Effects Analysis r Reliability Analysis Sftware Hazards Analysis Technical Manual Technical descriptin and peratin f the system Cntrl lgic sheets Graphics displays Site acceptance tests Installatin instructins System Drawings that identify: Field interfaces Intercnnectins t pwer cabinets System pwer Annunciatrs Ovatin Lgic Cabinet Upgrade: Optinal Scpe The fllwing items are custmer dependent and prvided as ptinal scpe: 1. LCD display fr cntrl rm interface 2. Infrastructure cabinet (if first Ovatin System) 3. Westinghuse site advisry supprt 4. Site demlitin and installatin 5. Design change (mdificatin) package implementatin r supprt 6. Licensing supprt creatin 7. Training fr peratrs, technicians r system engineers 8. Updates t existing rd cntrl technical manuals and drawings 9. Cyber security assessments/remediatin 10. Simulatr Update displays, step cunters and cntrl lgic Benefits Summary The Westinghuse Ovatin-based lgic cabinet upgrade ffers these benefits: Standardized slutin fr tw-, three- and fur- lp Westinghuse PWRs Multiple SPVs are reduced/eliminated Cntrller panel fits inside the same existing lgic cabinet ftprint Original rd cntrl lgic functinality reprduced n highly reliable Ovatin redundant cntrller (reliability greater than 99.9 percent) The system includes a standard interface t the plant data netwrk (Ovatin) system Minimal demlitin and installatin time (apprximately three days) Reuse f existing MCB switches and indicatrs with a sft display indicatin backup Lamp indicatrs replaced with LEDs I/O that is ht swappable and requires n calibratin Ht swappable pwer supplies that are mnitred Temperature and humidity mnitring 6

8 Benefits Summary (cnt.) New maintenance health and status features available n sft displays and advanced diagnstics enable lw-level fault detectin and reprting Manual rd speeds and cntrl bank verlaps are sftware based set-pints and easily adjustable Eliminatin f P/A cnverter hardware with Ovatin I/O replacement Shared inventry with ther Ovatin systems Eliminatin f spare parts inventry assciated with the 23 unique printed circuit card types needed fr the riginal slid state lgic cabinet Eliminatin f aging mechanical devices Reduced surveillance testing required (functins are implemented in sftware) Eliminates the need fr cil current prfile timing checks currently being perfrmed each utage in respnse t the Salem event Eliminates Bank Overlap checks Ovatin is a trademark r registered trademark f its respective wner. Other names may be trademarks f their respective wners Westinghuse Electric Cmpany LLC. All Rights Reserved NA