04 · Nuclear Energy Risks · Database
ETHZ Curated Nuclear Events Database
1,561 curated events from civil nuclear facilities (1946–2020, 37 countries) with failure sequences, contributing factors, INES annotations, cost estimates and references — delivered with an Excel access tool and a user manual.
events in the main table
period covered (snapshot of November 2020)
countries · 7 world regions
fields per event
What is inside
From event descriptions to failure sequences and costs
The database was developed at the ETH Zurich Chair of Entrepreneurial Risks (Prof. Didier Sornette) with Prof. Wolfgang Kröger, Dr. Spencer Wheatley, Dr. Ali Ayoub and Andrej Stankovski. This snapshot corresponds to the version released in November 2020; it is distributed by Albatrisk as-is, for research and professional use.
Main events table
Date, country, site, unit, operating mode, INES rating, description, origin and cause, event type, reactor type, significance, core relevance and references — 142 fields per event.
Failure sequences
For each event, the chain from prior event and initiating event through system and component failures, with severity colour codes and causal-link annotations.
Contributing factors
Human, technical, organisational and external factors: automatic actuation and operator failures, common-cause residuals, test & maintenance errors, design residuals, procedural errors and safety culture.
Economic loss estimates
Outage durations, capex/opex and replacement costs, plant losses, off-site repair, health and environmental costs, regulatory fines and total cost in constant 2013 USD with lower and upper limits.
Other facilities and precursors
114 events from research reactors, reprocessing, waste and fuel-fabrication facilities, and 288 NRC Accident Sequence Precursor / Significance Determination Process entries.
Statistics and charts
Events per reactor type, origin, cause, mode, normalised trends, INES distributions, initiating events and contributing factors — computed on any filtered subset.
Reading a failure sequence
Each event is described by the consecutive failures of different systems for the duration of the event. Systems are colour-coded by severity; the causal links between events and system failures are annotated with the codes below.
Severity
System affected
No significant failure of the system was observed, but the potential for a failure existed.
Partial system failure
The failure did not encompass the whole system and was limited to one or more redundant trains which may limit the operability of the system. The number of affected redundant trains is always mentioned if this information is available.
Complete system failure
The system could not fulfil its safety function as it failed to actuate or all redundant trains failed.
Causal links
- 0
- No connection between events/system failures
- 1
- Caused by the previous event/system failure
- 2
- Caused by the previous event/system from the other group
- 3
- Caused by the prior event or its affected system (mostly for the primary affected systems)
- I
- Caused by the initiating event or its affected system
- E
- Happened at the same time as the previous event and was caused by the initiating event
- S
- Happened at the same time as the previous event/system and was not caused by the initiating event or other system failure (independent)
- G
- Happened at the same time as the previous event and was caused by the same system failure or cause
- C
- Happened at the same time as the previous event and contributed to the event
How to use it
The Excel access tool in four steps
Load events
Open ETHZ_Database_Access_tool.xlsm, enable macros and press “Load Events”. The tool reads the database from Support_file.xlsx.
Display and filter
Press “Display Events”, define filters in the red filter blocks (date, region, country, INES, reactor type, origin, type…) and press “Apply Filter”.
Inspect
Open “Filtered Events” for the event list with reference hyperlinks, or “Failure Sequences” for the colour-coded failure chain of each event.
Statistics and export
Run the statistics on the filtered subset and export the results to a standalone Excel workbook saved next to the tool.
Requirements
- Microsoft Excel for Windows with macros enabled (the access tool uses VBA and ActiveX controls; a macOS-compatible version is not available).
- Extract the whole ETHZ_Nuclear_Events_Database_2020-11.zip archive into one folder — the access tool opens Support_file.xlsx from its own folder.
- Loading all events takes up to three minutes on first use.
Package contents
- ETHZ_Database_Access_tool.xlsm — Macro-enabled Excel workbook with the graphical interface: load events, filter, display failure sequences, compute statistics and export.
- Support_file.xlsx — The full database in raw tabular form. It is read by the access tool and must stay in the same folder with its original name. Not intended for direct use.
- ETHZ_Database_User_Manual.docx — User manual: installation, navigation, filter blocks, failure-sequence legend and export.
- README.txt — Package contents, requirements, citation, disclaimer and contact.
Download
Terms of use and access
Terms of use
- Free of charge for research, educational and professional use.
- Please cite the database and the reference publications below in any derived work.
- No redistribution of the files themselves; please refer colleagues to this page.
- Provided as-is, without warranty; corrections and additions are welcome.
Found an error or a missing event? Tell us. The database is a living work in progress.
Request the database
The package is free. We ask for your name, e-mail address and organisation so that we can keep track of who uses the database, inform you about updates and corrections, and understand how it is being used.
How to cite
Reference publications
Ali Ayoub, Andrej Stankovski, Wolfgang Kröger and Didier Sornette
The ETH Zurich Curated Nuclear Events Database: Layout, Event Classification, and Analysis of Contributing Factors
Reliability Engineering & System Safety 213, 107781 (2021)
Ali Ayoub, Andrej Stankovski, Wolfgang Kröger and Didier Sornette
Precursors and startling lessons: Statistical analysis of 1250 events with safety significance from the civil nuclear sector
Reliability Engineering & System Safety 214, 107820 (2021)