Due to the scarcity of Human Reliability Analysis (HRA) data, one of the key
elements of any HRA analysis is use of engineering judgment. The Electric Power
Research Institute (EPRI) HRA Calculator guides the user through the steps of any
HRA analysis and allows the user to choose among analytical HRA methods. It applies
Accident Sequence Evaluation Program (ASEP), Technique for Human Error Rate
Prediction (THERP), the HCR/ORE Correlation, and the Caused Based Decision Tree
Method (CBDTM). This program is intended to produce consistent results among
different analysts provided that the initial information is similar. Even with this
analytical approach, an HRA analyst must still render several judgments. The objective
of this study was to evaluate the use of engineering judgment applied to the
quantification of post-initiator actions using the HRA Calculator. The Comanche Peak
Steam Electric Station (CPSES) Level 1 Probabilistic Risk Assessment (PRA) HRA was
used as a database for examples and numerical comparison. Engineering judgments
were evaluated in the following ways: 1) Survey of HRA experts. Two surveys were completed, and the participants
provided a range of different perspectives on how they individually apply
engineering judgment.
2) Numerical comparison among the three methods.
3) Review of CPSES HRA and identification of judgments and the effects on the
overall results of the database.
The results of this study identified thirteen areas in which an HRA analyst must
interpret and render judgments on how to quantify a Human Error Probability (HEP) and
recommendations are provided on how current industry practitioners render these same
judgments. The areas are: identification and definition of actions to be modeled,
identification and definition of actions to be modeled, definition of critical actions,
definition of cognitive portion of the action, choice of methodology, stress level, rule-,
skill- or knowledge-based designation, timing information, training, procedures, human
interactions with hardware, recoveries and dependencies within an action, and review of
final HEP.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/3059 |
| Date | 12 April 2006 |
| Creators | Kohlhepp, Katherine D. |
| Contributors | Burchill, William E. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 1186738 bytes, electronic, application/pdf, born digital |
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