Common Technical Issue On I&C

Transcription

1 Common Technical Issue On I&C Chashma Unit-1 and 2 Pakistan by M.Ramzan Tahir IAEA Technical Meeting on Instrumentation and Control in SMRs At VIC Vienna, Austria (21 ~ 24 May, 2013)

2 Contents Plants Design Specifications Role Of I&C in Advance SMRs Technical Issue on I&C Systems in uint-1 and 2 2

3 Design Specifications Reactor Type Rated Thermal Power Gross Electrical Output Net Electrical Output Operating Pressure Operating Temperature Design Capacity Factor Design Life PWR, 2 Loop MW th 325 MWe 300 MWe 15.2 MPa o C 70 % 40 Years 3

4 Role of I&C IN Advance SMRs I&C systems are the nervous system of a nuclear power plant. They monitor all aspects of the plant s health. Purpose of I&C system architectures at Nuclear power plant is to enable and ensure safe and reliable power generation. 4

5 Role of I&C IN Advance SMRs The I&C systems provide the capability to control and regulate the plant systems manually and automatically during normal plant operation, and provide protection against unsafe plant operation.

6 Technical Issue on I&C Systems in uint-1 Control and Monitoring Systems Process Field instruments

7 Control and Monitoring Systems Plant Process Computer System (CPC) Turbine Emergency Trip System (ETS) Reheat Control System (RTC) In-Core Neutron Flux Measurement System (CIN) MCR Data Acquisition System (CDA) Radiation Monitoring System (RMS) 7

8 PLANT COMPUTER SYSTEM System Function Plant Process Computer is a data acquisition having about four thousands Analog / Digital inputs. This system provides online status of plant equipment and process parameter to plant operators in control room. 8

9 PLANT COMPUTER SYSTEM System Hardware CPC system consists of six DAQ stations, two main servers and twelve Operators Terminals. System is based on VME bus. Operating system is UNIX-V. ARCNet token ring is used between DAQ and Server. CPU Cards are from Motorola while other hardware is made by Chinese. 9

10 PLANT COMPUTER SYSTEM Problem Description Special graphic terminals (HST-480A) are used in CPC system as Operator Terminals. These Operator Terminals consist of a special single board computer. The spare Operator Terminals are not available now. The supplier has regretted to supply, being obsolete and out of manufacturing. 10

11 HST-480A

12 PLANT COMPUTER SYSTEM Work Scope of CS The HST480A terminal will be replaced by industrial PCs. All operator interface function software will be developed on Windows plateform. 12

13 Turbine Emergency Trip System System Function The Emergency Trip System (ETS) provides a redundant protection system for nuclear power plant turbine. This protection involves an automatic trip of the turbine if a hazardous condition exists that could lead to equipment damage. The ETS employs redundant protection through backup hardware and intelligent tripping logic. 13

14 Turbine Emergency Trip System System Function The following conditions are monitored: Turbine over speed Condenser vacuum EH fluid pressure Bearing oil pressure Thrust bearing wear Remote trip Customer Trip 14

15 Turbine Emergency Trip System Problem Description System uses Siemens S5 series PLC which has become obsolete. The system uses an Operator Test Panel which is a Westinghouse propriety product. It is out of production and has been discontinued since long. Monthly channel functional test cannot be performed if this panel is unavailable. 15

16 Operator Test Panel

17 Turbine Emergency Trip System Work scope of CS Replacement of existing Siemens S5 series PLCs (main PLC and backup PLC) along with Operator Test Panel, with Siemens S7-4XX series PLCs along with relevant HMI. 17

18 Reheat Control System System Function When steam at about 6.48 MPa and 281 ºC expands in the HP turbine, it attains moisture along with drop in temperature. Two Moisture Separator Reheaters are used to remove moisture and superheat the steam before entering in LP turbines. Reheat Temperature Controller (RTC) is used to control the second stage re-heater of the moisture separator units. RTC modulates the pneumatic control valves at inlet of the MSRs so as to regulate the main steam for reheating the exhaust steam from HP turbine to about 266ºC. 18

19 Reheat Control System Problem Description Obsolescence Control System is a Westinghouse propriety design which has been discontinued since long ago. Operator Panel uses two 486 CPUs which are not available. The supplier has regretted to supply. 19

20 RTC Cabinet

21 RTC Panel

22 Reheat Control System Work scope of CS Replacement of existing PC based control system with new system (Siemens PLC). 22

23 IN CORE FLUX MEASUREMENT SYSTEM System Function The IN-CORE Neutron Flux Monitoring System (CIN) is used to measure neutron flux distribution in the reactor. CIN is used during reactor start-up and Normal operation for: Calibrate ex-core nuclear instrumentation system. Providing fuel assembly burn-up data, estimate fuel burn-up level for refuelling and optimization. 23

24 IN CORE FLUX MEASUREMENT SYSTEM Detecting neutron flux distortion and tilt. To map the neutron flux distribution at least once every 30 full power days. 24

25 IN CORE FLUX MEASUREMENT SYSTEM System Configuration CIN system consists of three main parts, namely, Control Cabinets, Distribution Cabinet and Mechanical System. The purpose is to implement the operation, control, and data storage. 25

26 IN CORE FLUX MEASUREMENT SYSTEM Problem Description Obsolescence PCs (386) are obsolete. Flux acquisition racks and drive unit racks are not available. Scope of Work The objective is to re-design and replace the legacy control system with the PLC based control system. 26

27 CIN Cabinet

28 CDA System System Function Main Control Room Data Acquisition System is used to monitor about 500 temperature, pressure, level and differential pressure signals of both primary and secondary loop. These signals are displayed in MCR panels for operators' help. 28

29 CDA System System Hardware The system consists of analog input cards, RTD cards, and main/control cards, an RS-485 communication network and two industrial PCs with two CRT screens and a shared printer. The RS-485 communication network spans from Main Control Room (MCR) to six field rooms, in which the data acquisition units are located. 29

30 CDA System Problem Description Obsolescence Supplier has regretted to supply spares Work Scope Replacement of existing system with new system (FPGA based DAQ) system, keeping existing wiring and cabinets intact. 30

31 CDA Remote Unit

32 CDA Computer

33 CDA Block Diagram

34 Radiation Monitoring System Function Radiation Monitor System is used for monitoring radiation level at various plant locations. It comprises of following sub-systems. AAR : In-plant area Radiation Monitoring System for the Nuclear Island. AER : Effluent Radiation Monitoring System. APR : Process Radiation Monitoring System. ABR : BOP Radiation Monitoring System. 34

35 Radiation Monitoring System Problem Description Obsolescence The spares are not available. Computer (486 CPU) is obsolete. Scope Of work Working of System up gradation in progress. 35

36 Process Field instruments RTD Replacement on cold leg of Reactor coolant system (SRC) Lubrication oil Level switch replacement of Reactor coolant Pump (RCP). Sensor Cleaning of Analytical instrument of water purification system. Replacement of Level Transmitter of Rad.Liquid Waste storage tank. 36

37 Replacement of RTD (Cold leg) Problem Description Permanent welding on cold leg. De-welding required for removing. Work Problem due to Radiation Hazard. Remedial Action. Replace with Swagelok replacement in future fitting and easier for 37

38 Level Switch Replacement of Lubrication oil of RCP Problem Desription. Level Electronics Switch Malfunctioning due to Radiation. Reactor trip repeatedly. Remidial Action Replace with Float type level switch. 38

39 Sensor Cleaning of Analytical Instrument Problem Description Erratic behavior Improper Output as per requirement. Remedial Action Cleaning of Sensor in each month. 39

40 Replacement of Level Transmitter of Rad,liquid Waste Tank Vibration Method was used for level sensing (water and resin) with string and ball. Problem Description. Ball Detach from string Improper Out put Remedial Action Replace with RADAR type Transmitter. 40

41 Thanks