OVERVIEW OF HUMAN RELIABILITY ANALYSIS METHODS

1. IAEA.PNRA.05.05 Stetkar & Associates 1 OVERVIEW OFHUMAN RELIABILITY ANALYSIS METHODS by John W. Stetkar Presented to National Training Course on Probabilistic Safety Assessment Islamabad, Pakistan May 2 - 6, 2005 IAEA Project C7-PAK/9/028-001

2. IAEA.PNRA.05.05 Stetkar & Associates 2

3. IAEA.PNRA.05.05 Stetkar & Associates 3 HUMAN RELIABILITY ANALYSIS GOALS SUFFICIENT DETAIL TO UNDERSTAND AND DOCUMENT ALL IMPORTANT FACTORS THAT AFFECT HUMAN PERFORMANCE IDENTIFY AND ACCOUNT FOR DEPENDENCIES ACCOUNT FOR PLANT OPERATORS� EXPERTISE HUMAN ERROR RATES ARE INTERNALLY CONSISTENT HUMAN ERROR RATES ARE CONSISTENT WITH PLANT EXPERIENCE AND OTHER EVIDENCE IDENTIFY, QUANTIFY, AND DISPLAY UNCERTAINTY

4. IAEA.PNRA.05.05 Stetkar & Associates 4 TYPES OF HUMAN ACTIONS

5. IAEA.PNRA.05.05 Stetkar & Associates 5 GENERAL TYPES OF HUMAN ACTIONS TYPE A: PRE-INITIATING EVENT ACTIONS TYPE B: ACTIONS THAT CAUSE AN INITIATING EVENT TYPE C: POST-INITIATING EVENT ACTIONS TYPE CP: PROCEDURE-BASED ACTIONS TYPE CR: RECOVERY ACTIONS

6. IAEA.PNRA.05.05 Stetkar & Associates 6 PRE-INITIATING EVENT ACTIONS UNDETECTED ERRORS THAT LEAVE EQUIPMENT DISABLED ERRORS TYPICALLY OCCUR DURING TESTING MAINTENANCE CALIBRATION INSPECTION ERRORS OF COMMISSION, OMISSION, AND CHECKING INCLUDE IN SYSTEM ANALYSIS MODELS

7. IAEA.PNRA.05.05 Stetkar & Associates 7 ACTIONS THAT CAUSE AN INITIATING EVENT FULL-POWER PSAs TYPICALLY ASSUME CONTRIBUTIONS ARE INCLUDED IN DATA FOR TRANSIENT AND LOCA INITIATING EVENT FREQUENCIES QUANTIFIED EXPLICITLY IN MODELS FOR PLANT-SPECIFIC SUPPORT SYSTEM INITIATING EVENTS IMPORTANT CONTRIBUTIONS TO PLANT-SPECIFIC HUMAN-INDUCED INITIATING EVENTS DURING LOW POWER AND SHUTDOWN MODES DEPENDENCIES WITH POST-INITIATOR ACTIONS

8. IAEA.PNRA.05.05 Stetkar & Associates 8 POST-INITIATING EVENT ACTIONS ACTIONS THAT ARE REQUIRED AFTER AN INITIATING EVENT PRIMARILY ACTIONS THAT ARE IMPORTANT TO PREVENT CORE DAMAGE CONTAINMENT FAILURE KEYED TO EVENT SCENARIOS THAT INVOLVE ROUTINE RESPONSE TO AN INITIATING EVENT PROCEDURALLY-GUIDED ALTERNATIVES RECOVERY ACTIONS ACCIDENT MANAGEMENT ACTIONS

9. IAEA.PNRA.05.05 Stetkar & Associates 9 RECOVERY ACTIONS ACTIONS MAY NOT BE GUIDED BY WRITTEN PROCEDURES NOT A WELL-DEFINED CONCEPT SOME PROCEDURE-BASED ACTIONS MAY BE "RECOVERY" TREATMENT DEPENDS ON SCOPE OF PSA MODELS OFTEN DETERMINED BY IMPORTANT CONTRIBUTORS FROM FIRST QUANTIFICATION OFTEN ADDED TO MODELS AS PSA RESULTS ARE REFINED MAY INCLUDE SEVERE ACCIDENT MANAGEMENT ACTIONS

10. IAEA.PNRA.05.05 Stetkar & Associates 10 RECOVERY ACTIONSREPAIRS OF FAILED EQUIPMENT RESTORE FAILED PATHS FOR SUCCESS STRONG CORRELATION WITH TIME SCENARIO-DEPENDENT (ESPECIALLY CAUSE FOR FAILURE) CAREFUL EVALUATION OF ENGINEERING, OPERATIONS, MAINTENANCE NORMALLY NOT INCLUDED IN PSA (EXCEPT FOR STATION BLACKOUT CONDITIONS IN SOME STUDIES)

11. IAEA.PNRA.05.05 Stetkar & Associates 11 RECOVERY ACTIONSALIGN ALTERNATE SYSTEMS OR EQUIPMENT NEW OR ALTERNATE PATHS FOR SUCCESS STRONG CORRELATION WITH PROCEDURES AND TRAINING SCENARIO-DEPENDENT (ESPECIALLY PREVIOUS ACTIONS) EVALUATED BY SAME METHODS AS OTHER POST-INITIATOR ACTIONS MODERN HRA METHODS DO NOT DISTINGUISH BETWEEN "PROCEDURE-BASED ACTIONS" AND "RECOVERY ACTIONS"

12. IAEA.PNRA.05.05 Stetkar & Associates 12 HUMAN RELIABILITY ANALYSIS FRAMEWORK

13. IAEA.PNRA.05.05 Stetkar & Associates 13 SYSTEMATIC HUMAN ACTIONRELIABILITY PROCEDURE (SHARP) SPONSORED BY ELECTRIC POWER RESEARCH INSTITUTE (EPRI) ORIGINAL SHARP DOCUMENT (EPRI NP-3583, 1984) FRAMEWORK FOR SYSTEMATIC IDENTIFICATION AND EVALUATION OF HUMAN ACTIONS EMPHASIS ON PROCESS AND DOCUMENTATION COMPATIBLE WITH ANY HUMAN ERROR RATE QUANTIFICATION METHOD

14. IAEA.PNRA.05.05 Stetkar & Associates 14 SHARP (continued) UPDATED SHARP-1 DOCUMENT (EPRI RP-3206, 1990) LESSONS LEARNED FROM SHARP BENCHMARK APPLICATIONS EXPERIENCE FROM HUMAN RELIABILITY ANALYSIS PRACTITIONERS ENHANCED INTEGRATION OF HUMAN RELIABILITY ANALYSIS WITH PLANT MODELING TASKS IMPORTANCE OF DEPENDENCIES BETWEEN HUMAN ACTIONS EMPHASIZE ITERATIVE NATURE OF ANALYSIS PROCESS

15. IAEA.PNRA.05.05 Stetkar & Associates 15 THE SEVEN BASIC STEPS OF SHARP

16. IAEA.PNRA.05.05 Stetkar & Associates 16 INTERFACES OF HRAWITH MAJOR PSA TASKS

17. IAEA.PNRA.05.05 Stetkar & Associates 17 A TECHNIQUE FORHUMAN EVENT ANALYSIS (ATHEANA) SPONSORED BY U.S. NUCLEAR REGULATORY COMMISSION METHODOLOGY DEVELOPMENT DOCUMENT (NUREG/CR-6350, 1996) EXAMINATION OF ACTUAL HUMAN ERROR EVENTS DETERMINE "ERROR-FORCING CONTEXT" FOR SIGNIFICANT ERRORS IMPLEMENTATION GUIDELINES (NUREG-1624, 2000) "SECOND GENERATION" HRA METHODOLOGY

18. IAEA.PNRA.05.05 Stetkar & Associates 18 ATHEANA OBSERVATIONS SEVERE ERRORS ARE NOT CAUSED BY SIMPLE FAILURES TO FOLLOW PROCEDURAL STEPS CAUSES FOR SEVERE ERRORS: UNEXPECTED CONDITIONS NOT ADDRESSED BY PROCEDURES OR TRAINING MISDIAGNOSIS OF CONDITIONS OR REQUIRED RESPONSE REFUSAL TO BELIEVE CONTRADICTORY INDICATIONS OR INFORMATION "ERRORS OF COMMISSION" SCENARIO CONTEXT IS THE MOST IMPORTANT FACTOR THAT DETERMINES LIKELIHOOD OF ERROR PLANT CONDITIONS HUMAN PERFORMANCE-SHAPING FACTORS

19. IAEA.PNRA.05.05 Stetkar & Associates 19 ERROR-FORCING CONTEXT CONDITIONS THAT INCREASE LIKELIHOOD OF ERROR PLANT BEHAVIOR OUTSIDE EXPECTED RANGE PLANT BEHAVIOR NOT UNDERSTOOD TRUE INDICATIONS OF ACTUAL PLANT STATUS NOT RECOGNIZED PROCEDURES NOT DIRECTLY APPLICABLE SYSTEMATIC APPROACH TO EXAMINE PSA SCENARIOS FOR CONDITIONS THAT INCREASE LIKELIHOOD OF ERROR PLANT-SPECIFIC PSA MODELS INSIGHTS FROM HUMAN ERROR EXPERIENCE

20. IAEA.PNRA.05.05 Stetkar & Associates 20 MULTIDISCIPLINARY HRA FRAMEWORK

21. IAEA.PNRA.05.05 Stetkar & Associates 21 THE TEN BASIC STEPS OF ATHEANA

22. IAEA.PNRA.05.05 Stetkar & Associates 22 QUANTIFICATION METHODS

23. IAEA.PNRA.05.05 Stetkar & Associates 23 HANDBOOK METHODS ANALYSTS APPLY TABULATED DATA TO LOGIC MODELS THAT REPRESENT EACH HUMAN ACTION OR TASK EXAMPLES TECHNIQUE FOR HUMAN ERROR RATE PREDICTION (THERP, NUREG/CR-1278, 1983) ACCIDENT SEQUENCE EVALUATION PROGRAM (ASEP, NUREG/CR-4772, 1987) HUMAN ERROR ASSESSMENT AND REDUCTION TECHNIQUE (HEART, WILLIAMS, 1988) SELECTED SUPPORTING ANALYSES FOR NUREG-1150 (NUREG/CR-4550, 1989-1990)

24. IAEA.PNRA.05.05 Stetkar & Associates 24 TIME-RELIABILITY CURVES ANALYSTS SELECT A TIME-RELIABILITY CURVE THAT REPRESENTS THE SITUATION, IDENTIFY A TIME WINDOW FOR HUMAN RESPONSE, DETERMINE THE BASE HUMAN ERROR RATE, AND MODIFY THE BASE ERROR RATE TO ACCOUNT FOR SCENARIO-SPECIFIC PERFORMANCE-SHAPING FACTORS EXAMPLES OPERATOR ACTION TREE TIME-RELIABILITY CORRELATIONS (OAT, NUREG/CR-3010, 1982) ACCIDENT SEQUENCE EVALUATION PROGRAM (ASEP, NUREG/CR-4772, 1987) HUMAN COGNITIVE RELIABILITY MODEL (HCR, EPRI, 1989)

25. IAEA.PNRA.05.05 Stetkar & Associates 25 EXPERT JUDGMENT ANALYSTS SELECT RELEVANT SCALES FOR HUMAN PERFORMANCE, ASSESS CONDITIONS FOR EACH SCALE, DEVELOP SCALE WEIGHTS, AND CORRELATE WEIGHTS TO KNOWN DATA (OR ANCHOR POINTS) FOR QUANTIFICATION EXAMPLES SUCCESS-LIKELIHOOD INDEX METHODOLOGY (SLIM, NUREG/CR-3518, 1984) PAIRED COMPARISONS DIRECT NUMERICAL ESTIMATION USE OF MULTI-ATTRIBUTE DECISION FUNCTIONS AND APPLICATIONS

26. IAEA.PNRA.05.05 Stetkar & Associates 26 NORMALIZED CORRELATIONS ANALYSTS USE CORRELATIONS TO TRANSLATE MEASURABLE CONDITIONS FROM A PLANT TRAINING SIMULATOR INTO A HUMAN ERROR RATE QUANTIFICATION MODEL APPLIED PRIMARILY FOR CONTROL ROOM OPERATOR DETECTION, DIAGNOSIS, AND DECISION-MAKING PROCESSES EXAMPLES HUMAN COGNITIVE RELIABILITY MODEL (HCR, EPRI, 1989) OPERATOR RELIABILITY EXPERIMENTS (ORE, EPRI, 1990; FRENCH PROJECTS)

27. IAEA.PNRA.05.05 Stetkar & Associates 27 REPRESENTATIONAL ANALYSTS DEVELOP A STRUCTURED REPRESENTATION OF HUMAN ACTIONS TO SYSTEMATICALLY IDENTIFY SPECIFIC HUMAN ERROR MODES THAT COULD AFFECT ERROR RATES EXAMPLES CONFUSION MATRIX DECISION TREE OPERATOR ACTION TREE (OAT, NUREG/CR-3010, 1982) A TECHNIQUE FOR HUMAN EVENT ANALYSIS (ATHEANA, NUREG-1624, 2000)

28. IAEA.PNRA.05.05 Stetkar & Associates 28 MOST POPULAR QUANTIFICATION METHODS TABULATED ERROR RATES TIME-RELIABILITY CORRELATIONS EXPERT ELICITATION

29. IAEA.PNRA.05.05 Stetkar & Associates 29 TABULATED ERROR RATES(THERP)

30. IAEA.PNRA.05.05 Stetkar & Associates 30 THERP TECHNIQUE FOR HUMAN ERROR PREDICTION (THERP) SWAIN AND GUTTMAN (NUREG/CR-1278, 1983)

31. IAEA.PNRA.05.05 Stetkar & Associates 31 THERP (continued) DETAILED TASK ANALYSIS EMPHASIS ON CRITICAL PROCEDURE STEPS DEVELOPMENT OF THERP TREES STRUCTURED LOGIC FOR TASK EVALUATION DOCUMENTATION OF ANALYSIS FACILITATE COMPUTATION OF HUMAN ERROR RATES

32. IAEA.PNRA.05.05 Stetkar & Associates 32 THERP (continued) TABULATED HUMAN ERROR RATES ("BASIC HUMAN ERROR PROBABILITIES", BHEP) ERROR RATES PRIMARILY FROM AUTHORS� JUDGMENT PERFORMANCE-SHAPING FACTORS TASK COMPLEXITY AVAILABLE PERSONNEL TRAINING AVAILABLE TIME DEPENDENCE AMONG PERSONNEL DEPENDENCE AMONG TASKS USE OF SCREENING VALUES TO CONTROL SCOPE OF ANALYSIS

33. IAEA.PNRA.05.05 Stetkar & Associates 33 HRA EVENT TREE OFHYPOTHETICAL CALIBRATION TASKS (SMALL AND LARGE MISCALIBRATIONS)

34. IAEA.PNRA.05.05 Stetkar & Associates 34 THERP BENEFITS EASY TO USE MODEST COST TABULATED VALUES REDUCE NEED FOR ANALYST JUDGMENT SELECTION RULES REDUCE VARIABILITY IN RESULTS NO SPECIALIZED SOFTWARE NEEDED

35. IAEA.PNRA.05.05 Stetkar & Associates 35 THERP LIMITATIONS EXCESSIVE EMPHASIS ON PROCEDURAL DETAILS DETAILED MODELS MASK TRUE CAUSES FOR ERRORS FALSE CONFIDENCE THAT ANALYSES ARE VERY PRECISE NO STRUCTURED INPUT FROM PLANT PERSONNEL LIMITED USE FOR UNDERSTANDING IMPORTANT ISSUES AND RECOMMENDING IMPROVEMENTS

36. IAEA.PNRA.05.05 Stetkar & Associates 36 TIME-RELIABILITY CORRELATIONS(ASEP, HCR)

37. IAEA.PNRA.05.05 Stetkar & Associates 37 ASEP ACCIDENT SEQUENCE EVALUATION PROGRAM (ASEP) SWAIN (NUREG/CR-4772, 1987) EXPANDED EARLIER WORK IN THERP TO EMPHASIZE COGNITIVE ASPECTS OF DYNAMIC ACTIONS METHODOLOGY DEVELOPED FOR ASEP PROGRAM AND NUREG-1150 ANALYSES

38. IAEA.PNRA.05.05 Stetkar & Associates 38 ASEP (continued) ANALYSIS OF POST-INITIATOR DYNAMIC ACTIONS TWO CONTRIBUTIONS TO HUMAN ERROR DIAGNOSIS: ACCOUNTS FOR IDENTIFICATION, DIAGNOSIS, EVALUATION, AND DECISION ERRORS DURING COGNITIVE PHASE OF RESPONSE (COGNITIVE ERRORS) POST-DIAGNOSIS: ACCOUNTS FOR MISOPERATION OF EQUIPMENT DURING EXECUTION PHASE OF RESPONSE (IMPLEMENTATION, "SLIP" ERRORS)

39. IAEA.PNRA.05.05 Stetkar & Associates 39 ASEP (continued)MODEL FOR PRE-DIAGNOSIS ANDPOST-DIAGNOSIS ACTIONS

40. IAEA.PNRA.05.05 Stetkar & Associates 40 ASEP (continued) INITIATION TIME (T0) AND TOTAL AVAILABLE TIME WINDOW (Tm) SCENARIO-SPECIFIC THERMAL-HYDRAULIC ANALYSES SCENARIO-SPECIFIC SIMULATOR RUNS FSAR OR DESIGN-BASIS ANALYSES SIMPLIFIED ENGINEERING CALCULATIONS IMPLEMENTATION TIME (Ta) EQUIPMENT MANIPULATIONS RESPONSE TIME FOR LOCAL ACTIONS ACTIVE CONTROLS (TIME TO COOL DOWN, REDUCE PRESSURE, ETC.) TASK ANALYSES, WALKDOWNS DISCUSSIONS WITH PLANT OPERATORS

41. IAEA.PNRA.05.05 Stetkar & Associates 41 ASEP (continued) COGNITIVE ERROR RATE EVALUATED FROM ASEP TIME-RELIABILITY CORRELATION ADJUSTED TO ACCOUNT FOR QUALITY OF PROCEDURES, TRAINING, EXPERIENCE, ETC. IMPLEMENTATION ERROR RATE EVALUATED BY METHOD SIMILAR TO THERP ADJUSTED TO ACCOUNT FOR TYPE OF ACTION, LOCATION, STRESS, ETC.

42. IAEA.PNRA.05.05 Stetkar & Associates 42 ASEP NOMINAL DIAGNOSIS MODEL

43. IAEA.PNRA.05.05 Stetkar & Associates 43 ASEP BENEFITS EXPLICIT TREATMENT OF TIME DEPENDENCIES DIRECT RELATION TO SPECIFIC SCENARIO PROGRESSION ACCOUNTS FOR VARIABILITY IN PROCEDURES, TRAINING, ETC. CORRELATION REDUCES NEED FOR ANALYST JUDGMENT REDUCED VARIABILITY IN RESULTS NO SPECIALIZED SOFTWARE NEEDED

44. IAEA.PNRA.05.05 Stetkar & Associates 44 ASEP LIMITATIONS NO VALIDATION OF TIME-RELIABILITY CORRELATION REQUIRED ANALYSES TO ESTIMATE T0 AND Tm ADDITIONAL METHODS REQUIRED FOR IMPLEMENTATION ERRORS FALSE CONFIDENCE THAT ANALYSES ARE VERY PRECISE LIMITED INPUT FROM PLANT PERSONNEL LIMITED USE FOR UNDERSTANDING IMPORTANT ISSUES AND RECOMMENDING IMPROVEMENTS

45. IAEA.PNRA.05.05 Stetkar & Associates 45 HCR HUMAN COGNITIVE RELIABILITY MODEL (HCR) OPERATOR RELIABILITY EXPERIMENTS (ORE) SPONSORED BY ELECTRIC POWER RESEARCH INSTITUTE (EPRI) EPRI NP-6560-L, 1989 EPRI RP-2847, 1990

46. IAEA.PNRA.05.05 Stetkar & Associates 46 HCR (continued) ANALYSIS OF POST-INITIATOR DYNAMIC ACTIONS THREE CONTRIBUTIONS TO HUMAN ERROR PARAMETER P1: ACCOUNTS FOR COGNITIVE ERRORS DURING EVENT DIAGNOSIS PHASE OF RESPONSE PARAMETER P2: ACCOUNTS FOR OPERATOR RESPONSE TIME INCLUDING DIAGNOSIS, EVALUATION, DECISION, AND ACTION (TRADITIONAL TIME-RELIABILITY PORTION OF MODEL) PARAMETER P3: ACCOUNTS FOR "SLIPS" AND MISOPERATION OF EQUIPMENT DURING IMPLEMENTATION PHASE OF RESPONSE

47. IAEA.PNRA.05.05 Stetkar & Associates 47 HCR (continued)PARAMETER P1 BASIC PARAMETER OF THE MODEL EXAMPLES OF CAUSES PROBLEMS WITH PROCEDURES HUMAN-MACHINE INTERFACE PROBLEMS MISCOMMUNICATION BETWEEN CREW MEMBERS SIGNIFICANT CONTRIBUTION TO OBSERVED ERRORS DURING SOME SIMULATOR EXPERIMENTS DOMINATES TIME-BASED AND "SLIP" ERRORS FOR SPECIFIC SCENARIOS EVALUATED BY DECISION TREE METHOD SIMILAR TO THERP

48. IAEA.PNRA.05.05 Stetkar & Associates 48 HCR (continued)PARAMETER P2

49. IAEA.PNRA.05.05 Stetkar & Associates 49 HCR (continued)PARAMETER P2 TIME WINDOW, Tw REALISTIC TRANSIENT ANALYSES SCENARIO-SPECIFIC THERMAL-HYDRAULIC ANALYSES CORRECTIONS TO ACCOUNT FOR MANIPULATION TIME MEDIAN RESPONSE TIME, T1/2 PLANT-SPECIFIC SIMULATOR EXPERIMENTS EPRI ORE DATABASE INTERVIEWS WITH TRAINING PERSONNEL INTERVIEWS WITH OPERATORS DISPERSION PARAMETER, ? DERIVED FROM EPRI ORE DATABASE AVERAGE VALUE BASED ON ALL QUALIFIED DATA REFINEMENT BASED ON CUE / RESPONSE MODEL

50. IAEA.PNRA.05.05 Stetkar & Associates 50 TYPICAL ORE / HCR PLOT

51. IAEA.PNRA.05.05 Stetkar & Associates 51 HCR (continued)PARAMETER P3 BASIC PARAMETER OF THE MODEL SMALL CONTRIBUTION TO OBSERVED ERRORS DURING MOST SIMULATOR EXPERIMENTS PROVIDES LOWER-BOUND ERROR RATE FOR SCENARIOS WITH LONG TIMES AVAILABLE FOR DIAGNOSIS AND RESPONSE INCLUDED IN MODEL FOR COMPLETENESS EVALUATED BY DECISION TREE METHOD SIMILAR TO THERP

52. IAEA.PNRA.05.05 Stetkar & Associates 52 HCR BENEFITS EXPLICIT TREATMENT OF TIME DEPENDENCIES DIRECT USE OF SIMULATOR DATA CORRELATION REDUCES NEED FOR ANALYST JUDGMENT REDUCED VARIABILITY IN RESULTS NO SPECIALIZED SOFTWARE NEEDED

53. IAEA.PNRA.05.05 Stetkar & Associates 53 HCR LIMITATIONS NO VALIDATION OF TIME-RELIABILITY CORRELATION RESULTS VERY SENSITIVE TO ESTIMATES FOR TW AND T1/2 DIFFICULT MEASUREMENT OF MEDIAN RESPONSE TIMES ADDITIONAL METHODS REQUIRED TO ESTIMATE P1 AND P3 FALSE CONFIDENCE THAT ANALYSES ARE VERY PRECISE NO STRUCTURED INPUT FROM PLANT PERSONNEL LIMITED USE FOR UNDERSTANDING IMPORTANT ISSUES AND RECOMMENDING IMPROVEMENTS EPRI PROPRIETARY DATA

54. IAEA.PNRA.05.05 Stetkar & Associates 54 EXPERT ELICITATION(SLIM)

55. IAEA.PNRA.05.05 Stetkar & Associates 55 SLIM SUCCESS-LIKELIHOOD INDEX METHODOLOGY (SLIM) EMBREY (NUREG/CR-3518, NUREG/CR-4016, 1985)

56. IAEA.PNRA.05.05 Stetkar & Associates 56 SLIM (continued) ANALYSIS OF POST-INITIATOR DYNAMIC ACTIONS ACTIONS EVALUATED SITUATIONALLY BASED ON RATING OF PERFORMANCE-SHAPING FACTORS ACCOMPLISHED BY A TEAM OF OPERATORS AND PSA ANALYSTS "SUCCESS-LIKELIHOOD INDEX" SOMETIMES TRANSFORMED TO "FAILURE-LIKELIHOOD INDEX"

57. IAEA.PNRA.05.05 Stetkar & Associates 57 SLIM (continued)PERFORMANCE-SHAPING FACTORS (PSF) SEVEN PERFORMANCE-SHAPING FACTORS NORMALLY EVALUATED FOR EACH ACTION TASK COMPLEXITY PLANT INTERFACE AND INDICATIONS OF CONDITION ADEQUACY OF TIME TO COMPLETE ACTION SIGNIFICANT PRECEDING AND CONCURRENT ACTIONS PROCEDURAL GUIDANCE TRAINING AND EXPERIENCE FOR THE SITUATION STRESS OTHER PSFs MAY BE USED IF WARRANTED BY SITUATION

58. IAEA.PNRA.05.05 Stetkar & Associates 58 SLIM (continued)EXPERT ELICITATION EVALUATION TEAMS EACH CREW OF CONTROL ROOM OPERATORS OPERATOR TRAINING PERSONNEL OFF-SHIFT OPERATIONS SUPERVISORY PERSONNEL PSA TEAM ACTIONS MAY BE GROUPED BY PATTERNS OF PSF WEIGHTS SIMILAR TO SKILL, RULE, AND KNOWLEDGE CLASSIFICATIONS SIMPLIFIES CALCULATIONS - ACTIONS EVALUATED IN GROUP DIFFICULT AND CONTROVERSIAL PROCESS FAILURE-LIKELIHOOD INDEX CALCULATED FROM COMBINATION OF PSF RATINGS AND NORMALIZED WEIGHTS

59. IAEA.PNRA.05.05 Stetkar & Associates 59 SLIM (continued)CALIBRATION OF HUMAN ERROR RATES DEFINE GROUPS OF SIMILAR ACTIONS INCLUDE AT LEAST TWO "CALIBRATION TASKS" IN EACH GROUP OF ACTIONS SIMILAR TO OTHER ACTIONS IN THE GROUP HAVE "KNOWN" OR "ACCEPTED" HUMAN ERROR RATES BEST- AND WORST-CASE HUMAN ERROR RATES FOR THE GROUP BOUNDING CALCULATIONS FROM OTHER HRA METHODS RANGES OF REPORTED EXPERIENCE EXPERT OPINION OF THE TEAM USE "CALIBRATION CURVE" TO CORRELATE FAILURE-LIKELIHOOD INDEX VALUES TO HUMAN ERROR RATES

60. IAEA.PNRA.05.05 Stetkar & Associates 60 SLIM (continued)SOURCES OF UNCERTAINTY CONTRIBUTIONS TO UNCERTAINTY VARIABILITY OF PSF RATINGS WITHIN EACH TEAM OF EXPERTS VARIABILITY BETWEEN TEAMS INHERENT UNCERTAINTY IN "CALIBRATION" ERROR RATES RESULTS INCLUDE ALL CONTRIBUTIONS EACH EVALUATION TEAM ASSIGNED EQUAL WEIGHT NARROW UNCERTAINTY DISTRIBUTIONS FROM CLOSE CONSENSUS ON "ROUTINE" ACTIONS BROAD UNCERTAINTY DISTRIBUTIONS FROM DIVERSE OPINIONS ON "EXTRAORDINARY" ACTIONS MEAN ERROR RATE CALCULATED FROM FINAL COMPOSITE UNCERTAINTY DISTRIBUTION

61. IAEA.PNRA.05.05 Stetkar & Associates 61 SLIM BENEFITS DIRECT INPUT FROM PLANT OPERATORS IDENTIFIES MAJOR CONTRIBUTORS TO OPERATOR ERRORS CONSENSUS EVALUATION PROCESS IS EXCELLENT TRAINING RESULTS PROVIDE FEEDBACK FOR IMPROVEMENTS TO TRAINING, PROCEDURES, DESIGN EXPLICIT TREATMENT OF UNCERTAINTIES NO SPECIALIZED SOFTWARE NEEDED

62. IAEA.PNRA.05.05 Stetkar & Associates 62 SLIM LIMITATIONS TIME AND SCHEDULE REQUIREMENTS FOR OPERATOR EVALUATIONS NEED TO VERIFY THAT OPERATORS REMAIN CONSISTENT AND UNBIASED DURING PSF EVALUATION PROCESS NO VALIDATION OF FAILURE-LIKELIHOOD INDEX CORRELATION DIFFICULT IDENTIFICATION OF ACTION GROUPS RESULTS VERY SENSITIVE TO SELECTION OF CALIBRATION TASKS AND ASSIGNMENT OF BOUNDING ERROR RATES

63. IAEA.PNRA.05.05 Stetkar & Associates 63 HUMAN RELIABILITY ANALYSIS DOCUMENTATION

64. IAEA.PNRA.05.05 Stetkar & Associates 64 DOCUMENTATION MOST COMMON DEFICIENCY NOTED IN REVIEWS DETERMINES CREDIBILITY OF ANALYSIS INTEGRATE QUALITATIVE AND QUANTITATIVE ANALYSES SYSTEMATICALLY ORGANIZE INFORMATION IDENTIFY DIFFERENT OPERATOR RESPONSE SCENARIOS SUCCESS CRITERIA BASIS FOR RESPONSE TIME WINDOWS ASSUMPTIONS PROCEDURE REFERENCES DEPENDENCIES IMPORTANT PERFORMANCE SHAPING FACTORS

65. IAEA.PNRA.05.05 Stetkar & Associates 65 DOCUMENTATIONQUALITATIVE ANALYSIS HUMAN ACTION NAME: ____________________ HUMAN ACTION IDENTIFIER(S): ____________________ 1. REQUIRED RESPONSE 2. TASK ELEMENTS 3. PSA SCENARIOS THAT INCLUDE THE ACTION 4. TIME WINDOW FOR RESPONSE IN EACH SCENARIO 5. SCENARIO-SPECIFIC SUCCESS CRITERIA 6. SOURCES OF DEPENDENCE

66. IAEA.PNRA.05.05 Stetkar & Associates 66 1. REQUIRED RESPONSE BRIEFLY DESCRIBE THE ACTION IN GENERAL TERMS PURPOSE OF THE ACTION CUES OR CONDITIONS THAT REQUIRE THE ACTION WHO PERFORMS THE ACTION WHERE THE ACTION IS PERFORMED WHAT MANIPULATIONS ARE REQUIRED EQUIPMENT AND SYSTEMS

67. IAEA.PNRA.05.05 Stetkar & Associates 67 2. TASK ELEMENTS DOCUMENT FUNCTIONAL TASKS THAT ARE RELEVANT TO THE PSA MODELS INCLUDE SUFFICIENT DETAIL TO UNDERSTAND MAJOR TASK ELEMENTS DO NOT SIMPLY LIST STEPS IN A PROCEDURE PURPOSE IS TO IDENTIFY IMPORTANT FACTORS THAT MAY AFFECT HUMAN PERFORMANCE SUMMARY SHOULD INCLUDE PROCEDURE REFERENCES FREQUENCY OF PERFORMANCE (FOR ROUTINE ACTIONS) TASK BREAKDOWN

68. IAEA.PNRA.05.05 Stetkar & Associates 68 TASK BREAKDOWN 1. TASK: DESCRIBE REQUIRED ACTIONS 2. EQUIPMENT: IDENTIFY EQUIPMENT THAT IS OPERATED 3. LOCATION: IDENTIFY LOCATION OF EQUIPMENT 4. PERSONNEL: IDENTIFY PERSONNEL WHO PERFORM THE ACTION 5. TIME REQUIRED: ESTIMATE TIME REQUIRED TO PERFORM THE ACTION AND PROVIDE THE BASIS 6. COMMENTS: INCLUDE ADDITIONAL INFORMATION ABOUT PROCEDURE STEPS, TRAINING, EQUIPMENT ACCESSIBILITY, SUPERVISOR VERIFICATION, ETC.

69. IAEA.PNRA.05.05 Stetkar & Associates 69 3. PSA SCENARIOS THAT INCLUDE THE ACTION DESCRIBE THE GENERAL SCENARIO THAT INCLUDES THE ACTION ("BASE CASE SCENARIO") IDENTIFY ALL INITIATING EVENTS FOR WHICH IT APPLIES DESCRIBE THE PREVIOUS PLANT RESPONSE BEFORE THE ACTION IS REQUIRED, INCLUDING OTHER OPERATOR ACTIONS DESCRIBE VARIATIONS IN THE SCENARIO THAT MAY AFFECT THE LIKELIHOOD FOR SUCCESS SYSTEM FAILURES PREVIOUS OPERATOR ERRORS CONDITIONS THAT AFFECT THE AVAILABLE RESPONSE TIME WINDOW EXTERNAL EVENT IMPACTS (FIRES, FLOODS, SEISMIC, ETC)

70. IAEA.PNRA.05.05 Stetkar & Associates 70 4. TIME WINDOW FOR RESPONSE IN EACH SCENARIO IDENTIFY THERMAL-HYDRAULIC CONDITIONS OR OPERATIONAL CONSTRAINTS THAT DETERMINE THE AVAILABLE RESPONSE TIME WINDOW FLOW RATE / LOSS OF LEVEL LOSS OF COOLING / HEATUP EQUIPMENT FAILURE PROCEDURAL GUIDANCE OR TRAINING DESCRIBE THE SPECIFIC PLANT CONDITIONS THAT DEFINE THE BEGINNING OF THE RESPONSE TIME PERIOD DESCRIBE THE SPECIFIC PLANT CONDITIONS THAT DEFINE THE END OF THE RESPONSE TIME PERIOD ESTIMATE THE TIME WINDOW FOR EACH FUNCTIONAL GROUP OF SCENARIOS DOCUMENT THE BASES FOR EACH ESTIMATE

71. IAEA.PNRA.05.05 Stetkar & Associates 71 5. SCENARIO-SPECIFIC SUCCESS CRITERIA DESCRIBE GROUPS OF SCENARIOS THAT REQUIRE DIFFERENT EVALUATIONS OF HUMAN PERFORMANCE INITIATING EVENT AVAILABLE TIME WINDOW AVAILABLE EQUIPMENT PREVIOUS OPERATOR ERRORS PROCEDURAL GUIDANCE AND TRAINING DEFINE A SEPARATE OPERATOR ACTION TOP EVENT, SPLIT FRACTION, OR BASIC EVENT FOR EACH GROUP OF SCENARIOS DESCRIBE THE SPECIFIC SUCCESS CRITERIA AND BOUNDARY CONDITIONS FOR EACH ACTION PURPOSE IS TO CLEARLY DEFINE EACH ACTION THAT WILL BE QUANTIFIED AND HOW IT RELATES TO THE PSA MODELS

72. IAEA.PNRA.05.05 Stetkar & Associates 72 6. SOURCES OF DEPENDENCE CLEARLY IDENTIFY ALL SOURCES OF DEPENDENCE THAT MAY AFFECT OPERATOR PERFORMANCE FOR EACH ACTION SIMILAR FUNCTIONS MULTIPLE OPTIONS / PRIORITIES PROCEDURES / TRAINING PERSONNEL / STAFFING LOCATION / COMMUNICATIONS PRECEDING SYSTEM SUCCESSES / FAILURES PRECEDING OPERATOR SUCCESSES / FAILURES DOCUMENT BASIS FOR ASSIGNED LEVEL OF DEPENDENCE / INDEPENDENCE

73. IAEA.PNRA.05.05 Stetkar & Associates 73 DOCUMENTATION*** "THE RULE" *** WRITE THE STORY WHILE YOU ARE DOING THE ANALYSIS DO NOT WAIT UNTIL THE END !