THE NUCLEAR SHELL MODEL
CONTENTS COMMUNICATION DESIGN OF LOW RESIDUAL ERROR PROBABILITY BASED ON FUNCTION SAFETY APPLY FMEDA TO GUIDE SELF-DIAGNOSTIC DESIGN FOR DIGITAL CIRCUIT BOARD A REUSABLE FUNCTIONAL SIMULATION VERI?CATION METHOD BASED ON UVM FOR FPGA PRODUCTS IN DAS THE METHOD OF FAILURE ANALYSIS FOR SAFETY-CRITICAL SYSTEM SOFTWARE BASED ON FORMALIZATION A STUDY ABOUT SOFTWARE V&V EVALUATION OF SAFETY I&C SYSTEM IN NUCLEAR POWER PLANT A STUDY ABOUT PRE-DEVELOPED SOFTWARE QUALI?CATION OF SMART DEVICES APPLIED IN NPP APPLICATIONS OF DATA MINING IN CONVENTIONAL ISLAND OF NUCLEAR POWER PLANT A HIERARCHICALLY STRUCTURED DOWN-TOP TEST EQUIPMENT DEBUGGING METHOD FOR RPS DISCUSSION FOR UNCERTAINTY CALCULATION OF CONTAINMENT LEAKAGE RATE RESEARCH AND IMPROVEMENT OF THE FLOWMETER FRACTURE PROBLEM OF CONDENSATE POLISHING SYSTEM IN NUCLEAR POWER PLANT STUDY ON OPTIMIZATION OF TURBIDITY CONTROL FOR SEAWATER DESALINATION SYSTEM IN NUCLEAR POWER PLANT OPTIMIZATION SCHEME OF TURBINE FREQUENCY REGULATION FOR PASSIVE NUCLEAR POWER PLANT RESEARCH AND OPTIMIZATION OF THE CONTROL COOPERATION BETWEEN TURBINE CONTROL SYSTEM AND DCS IN NUCLEAR POWER PLANT RISK ANALYSIS AND MANAGEMENT OF SOFTWARE V&V ACTIVITIES IN NPPS THE OPTIMIZATION OF SIEMENS TURBINE SYNCHRONIZATION STRATEGY RESEARCH ON THE VERI?CATION AND VALIDATION METHOD OF COMMERCIAL GRADE SOFTWARE IN NUCLEAR POWER PLANTS RESEARCH ON APPLICATION OF SEQUENCE CONTROL STRATEGY IN CONVENTIONAL ISLAND SYSTEM OF NUCLEAR POWER PLANT OPTIMIZATION OF CONTROL SOLUTION FOR DEAERATOR WATER LEVEL PROTECTION IN NUCLEAR POWER PLANT STUDY ON LAYOUT DESIGN AND MECHANICAL CALCULATION OF SEISMIC INSTRUMENTATION TUBING IN DIGITAL NUCLEAR POWER PLANT RESEARCH ON THE VERI?CATION AND VALIDATION METHOD OF SAFETY ANALYSIS SOFTWARE IN NUCLEAR POWER PLANTS A STUDY ABOUT CON?GURATION MANAGEMENT PROCESS FOR SAFETY DCS SOFTWARE V&V IN NUCLEAR POWER PLANT RESEARCH AND APPLICATION ON THE GATEWAY DESIGN OF DIGITAL CONTROL SYSTEM OF NUCLEAR POWER PLANT ALGORITHM RESEARCH OF THE ICCMS FOR QINSHAN PHASE II NPP BASED ON FIRMSYS PLATFORM APPLICATION OF MOSAIC INSTRUMENTS ON BACK-UP PANEL IN NUCLEAR POWER PLANT EQUIPMENT QUALI?CATION AND METHODS APPLICATION FOR CLASS 1E DIGITAL INSTRUMENTATION AND CONTROL SYSTEM STUDY ON ITEMIZED REQUIREMENTS OF SAFETY DIGITAL I&C SYSTEM IN NPP INSTRUMENT SURVIVABILITY ASSESSMENT DURING SEVERE ACCIDENT IN HPR1000 IN?UENCE ANALYSIS OF THE HALOGEN CABLES USED IN THE SAFETY RELATED CIRCUITS OF AP1000 NUCLEAR POWER PLANT NETWORK RISK MANAGEMENT BASED ON THE ALARP CRITERIA FOR NUCLEAR POWER PLANT ANALYSIS OF COMMUNICATION FAILURES IN RADIATION MONITORING SYSTEM OF A NUCLEAR POWER PLANT DESIGN OF GEOLOGICAL DISASTER MONITORING AND EARLY-WARNING SYSTEM FOR MOUNTAINOUS NUCLEAR FACILITIES RESEARCH ON ANTI-SEISMIC QUALI?CATION FOR NUCLEAR SAFETY CLASS I&C EQUIPMENT BASE ON SINGLE-FREQUENCY WAVE TECHNICAL THE APPROACHES OF PREVENTION, DETECTION, AND RESPONSE FOR CYBERSECURITY OF I&C SYSTEMS IN NPPS COMMUNICATION DESIGN OF LOW RESIDUAL ERROR PROBABILITY BASED ON FUNCTION SAFETY ABSTRACT AS THE SCALE OF PETROCHEMICAL INDUSTRY AND ELECTRIC POWER INDUSTRY GROWS, THE SAFETY INSTRUMENTED SYSTEM (SIS) BECOMES MORE COMPLEX AND THE SAFETY REQUIREMENTS OF SIS ARE MORE RIGOROUS GENERALLY, SIS IS COMPOSED OF SENSORS, ACTUATORS, LOGICAL CONTROL DEVICES, AND COMMUNICATION SYSTEMS THE DESIGN OF COMMUNICATION SYSTEM IS CONSIDERED AS A KEY PART OF SIS DESIGNING AND RESIDUAL ERROR PROBABILITY IS AN IMPORTANT INDEX TO EVALUATE SAFETY OF COM- MUNICATION THEREFORE, IT IS CRUCIAL TO COME UP WITH A METHOD TO DESIGN A COMMUNICATION SYSTEM WITH LOW RESIDUAL ERROR PROBABILITY ON THE BASIS OF DESIGN EXPERIENCE OF FIRMSYS WHICH IS A SAFETY INTEGRITY LEVEL (SIL) 3 SAFETY PLATFORM DEVELOPED BY CHINA TECHENERGY COOPERATION (CTEC) AND ACCORDING TO THE STANDARD IEC 61508, THIS ARTICLE PRESENTS NECESSARY DESIGN MEASURES TO REACH LOW RESIDUAL ERROR PROBABILITY INCLUDING DATA INTEGRITY ASSURANCE, DIAGNOSTIC TECHNIQUES, THE NUMBER OF BITS IN THE BLOCK, ETC AND ALSO IT PROVIDES THE DESIGN METHOD OF EACH ELEMENT THIS DESIGN METHOD IS APPLICABLE TO THE DESIGN OF THE COMMUNICATION PROTOCOL WHICH CAN MEET THE FUNCTIONAL SAFETY REQUIREMENT KEYWORDS: FUNCTION SAFETY RESIDUAL ERROR PROBABILITY FIRMSYS INTRODUCTION WITH THE LARGE-SCALE PRODUCTION OF PETROCHEMICAL INDUSTRY, ELECTRIC POWER AND OTHER INDUSTRIES, TO ENSURE THE SAFETY AND RELIABILITY OF SAFETY SYSTEMS AND AVOID MAJOR INDUSTRIAL ACCIDENTS BECOME MAIN CONCERNS OF SAFETY PRODUCTION THE DISASTERS THAT SHOCKED THE WORLD SUCH AS THE BHOPAL GAS SPILL IN INDIA, THE CHERNOBYL NUCLEAR POWER PLANT IN THE FORMER SOVIET UNION, HAVE GIVEN PEOPLE AN UNPRECEDENTED FOCUS ON SAFETY IN INDUSTRIAL PRODUCTION SIS IS A CATEGORY OF SAFETY-RELATED SYSTEMS (SRS), AND IT IS AN IMPORTANT MEASURE TO ENSURE PRODUCTION SAFETY SIS IS REQUIRED TO CORRECTLY PERFORM ITS SAFETY FUNCTIONS BEFORE A DANGEROUS EVENT OCCURS, TO AVOID OR REDUCE THE OCCURRENCE OF AN ACCIDENT [1] TYPICALLY, SIS SYSTEM CONSISTS OF SENSORS, ACTUATORS, LOGICAL CONTROL DEVICES, AND COMMUNICATION SYSTEMS THE DESIGN OF THE COMMUNICATION SYSTEM IS ONE OF THE KEY DESIGNS FOR THE SIS SYSTEM, AND COMMUNICATION RESIDUAL ERROR PROBABILITY IS A QUANTITATIVE INDEX TO EVALUATE COMMUNICATION SAFETY [2] THEREFORE, HOW TO DESIGN COMMUNICATION SYSTEMS WITH RELATIVELY LOW RESIDUAL ERROR PROBABILITY IS THE FOUNDATION OF THE SIS SYSTEM BASED ON DIGITAL CONTROL SYSTEM (DCS) TECHNOLOGY FIRMSYS IS A NUCLEAR POWER PLANT SAFETY CONTROL SYSTEM PLATFORM DEVELOPED BY CTEC, WHICH IS THE BRAIN AND NERVE CENTER OF A NUCLEAR POWER PLANT IT PLAYS A VITAL ROLE IN ENSURING THE SAFETY OF NUCLEAR POWER PLANT EQUIPMENT AND PERSONNEL AND THE ENVI- RONMENT THE SAFETY COMMUNICATION OF THE FIRMSYS MEETS BOTH THE NUCLEAR REQUIRE- MENTS AND THE FUNCTIONAL SAFETY REQUIREMENTS THIS PAPER FOCUSES ON A KEY INDEX OF SAFETY COMMUNICATION – THE RESIDUAL ERROR PROBABILITY OF COMMUNICATION, INCLUDING THE DE?NITION OF THE COMMUNICATION DESIGN REQUIREMENTS BASED ON THE FUNCTIONAL SAFETY IN ADDITION, BASED ON THE IEC 61508, IT SUMMARIZES AND ANALYZES THE DESIGN FACTORS OF SAFETY COMMUNICATION, AND UNI?ES THE FIRMSYS EXPERIENCE IN NUCLEAR POWER AND FUNCTIONAL SAFETY TO DESIGN A SAFETY COMMUNICATION RESIDUAL ERROR PROBABILITY REQUIREMENTS OF COMMUNICATION IN FUNCTIONAL SAFETY IEC 61508 PROPOSES TO USE SIL FOR EVALUATING THE RISK REDUCTION CAPABILITY OF A SAFETY FUNCTION PFD (PROBABILITY OF DANGEROUS FAILURE ON DEMAND) OR PFH (AVERAGE FREQUENCY OF DANGEROUS FAILURE [H?1]) ARE IMPORTANT QUANTITATIVE INDICATORS PFD IS USED FOR LOW DEMAND SIS AND PFH IS USED FOR HIGH DEMAND SIS [3] IN THIS PAPER, PFD IS TAKEN AS AN EXAMPLE, AND PFH CAN BE USED IN A SIMILAR WAY IN TERMS OF SAFETY COMMUNICATION REQUIREMENTS, IEC 61508 MAKES REFERENCE TO IEC 61784-3 WHICH RAISES COMMUNICATION RESIDUAL ERROR PROBABILITY AS A QUANTITATIVE EVALUATION INDEX THE COMMUNICATION RESIDUAL ERROR PROBABILITY IS USED TO MEASURE THE PROBABILITY THAT AN UNDIAGNOSED FAILURE WILL STILL OCCUR AFTER A SERIES OF MEASURES HAVE BEEN TAKEN IN STANDARD IEC 61784-3, THE COMMUNICATION RESIDUAL ERROR PROBABILITY IS REQUIRED TO BE FAR LESS THAN THE SIL REQUIREMENTS FOR THIS SAFETY FUNCTION LOOP, THAT IS, THE 1% FOR THE MAXIMUM SYSTEM PFD INDEX, AS SHOWN IN FIG 1: THE CORRESPONDING RELATIONSHIP OF RESIDUAL ERROR PROBABILITY, THE PFD AND THE SIL IS SHOWN IN THE FOLLOWING TABLE [3]: IN THE SIS SYSTEM DESIGN PROCESS, ?RST, IDENTIFY THE REQUIRED FUNCTIONS TO REDUCE THE ORIGINAL RISK TO AN ACCEPTABLE LEVEL ON THE BASIS OF HAZARD IDENTI?CATION AND RISK ANALYSIS, AND THE PFD REQUIREMENTS FOR THE FUNCTIONS SHOULD BE DETERMINED AFTERWARDS, DETERMINE THE CORRESPONDING SIL FOR THE DESIGNED SAFETY FUNCTIONS AND FURTHER THE SENSOR LOGIC PROCESSOR ACTUATOR PFD COMMUNICATION 1%PFD COMMUNICATION FIG 1 SAFETY FUNCTION LOOP THE NUCLEAR SHELL MODEL REQUIREMENTS FOR THE COMMUNICATION RESIDUAL ERROR PROBABILITY SHOULD BE ASSIGNED TO SIS BASED ON ITS SIL, AS SHOWN IN TABLE 1 AI PI E 1 PE Ð ÞNI Ð2Þ TABLE 1 CORRESPONDENCE OF RESIDUAL ERROR PROBABILITY, PFD AND SIL SIL PFD RESIDUAL ERROR PROBABILITY OF COMMUNICATION [1 0E-5,1 0E-4) [1 0E-7,1 0E-6) [1 0E-4,1 0E-3) [1 0E-6,1 0E-5) [1 0E-3,1 0E-2) [1 0E-5,1 0E-4) [1 0E-2,1 0E-1) [1 0E-4,1 0E-3) THE NUCLEAR SHELL MODEL RELATED DESIGN METHODS FOR THE RESIDUAL ERROR PROBABILITY OF COMMUNICATION THE PAPER EXPANDS THE DESIGN FACTORS SEPARATELY AS FOLLOWS: REDUNDANT CHECKSUM CODES THE MOST COMMONLY USED REDUNDANT CHECKSUM CODES IS CRC, WHEN THERE IS A CERTAIN NUMBER OF ERRORS IN THE COMMUNICATION DATA, THE CRC CAN DETECT THE COMMU- NICATION FAILURES, WHICH GREATLY REDUCES THE COMMUNICATION RESIDUAL ERROR PROBABILITY, SO CRC IS THE ?RST DESIGN FACTOR TO CONSIDER DIFFERENT CRC POLYNOMIALS HAVE DIFFERENT EFFECTS ON THE COMMUNICATION RESIDUAL ERROR PROBABILITY, AND THE CRITERIA ARE GIVEN FOR WHETHER A CRC POLYNOMIAL IS APPRO- PRIATE IN STANDARD IEC 61784-3 FIGURE 2 SHOWS THE DIFFERENCES BETWEEN THE CHANGING CURVES OF RESIDUAL ERROR PROBABILITY UNDER PROPER CRC POLYNOMIALS AND IMPROPER CRC POLYNOMIALS FIG 2 PROPER AND IMPROPER CRC POLYNOMIALS THE NUCLEAR SHELL MODEL INVESTIGATIONS FOR THE METHOD OF CRC HAVE SHOWN THAT FOR THE PARTICULAR CLASS OF SO- CALLED PROPER CRC POLYNOMIALS, A WEIGHTING FACTOR 2?R IS APPLICABLE WITHIN THE EQUATION TO BUILD AN APPROXIMATION THE RESIDUAL ERROR PROBABILITY APPROXIMATION FOR CRC POLYNOMIALS IS SHOWN IN EQ (3) BELOW [2] RCRCÐPEÞ 2R X N K¼DMIN N K PEK 1 PE Ð ÞNK Ð3Þ WHERE, DMIN REPRESENTS THE MINIMUM DISTANCE BETWEEN YARDS (THE MINIMUM HAMMING DISTANCE), N K REPRESENTS THE NUMBER OF COMBINATIONS N FETCH K, R REPRE- SENTS FOR THE LENGTH OF CRC EQUATION (3) SHOWS THAT THE COMMUNICATION RESIDUAL ERROR PROBABILITY BECOMES LOWER WITH THE INCREMENT OF R, WHICH MEANS THE SAFETY AND RELIABILITY OF COMMUNICATION IMPROVE THE NUMBER OF BITS IN THE BLOCK EQUATION (3) ALSO SHOWS THAT THE RELIABILITY OF COMMUNICATION WILL DETERIORATE AS THE NUMBER OF BITS IN THE BLOCK INCREASES DIFFERENT NUMBER OF BITS IN THE BLOCK WITH THE SAME CRC POLYNOMIAL CAN ALSO CAUSE THE SMALLEST HAMMING DISTANCE TO BE SMALLER, AS SHOWN IN THE FOLLOWING ILLUSTRATION [4, 5] SO YOU SHOULD CHOOSE THE PROPER NUMBER OF BITS IN THE BLOCK FOR THE COMMUNICATION DESIGN, AND REFER TO THE TABLE 2 (FIG 3) FIG 3 THE TREND OF HAMMING DISTANCE AS THE CODE VALUES INCREASE THE NUCLEAR SHELL MODEL {32} 16361– 32737– 32738– 32739– 114664+ 65503+ 65507+ 65507+ 65506+ 65506+ THE NUCLEAR SHELL MODEL