Plots of reactor data - Fukushima Daiichi - Units #1--#3

Jorge Stolfi
2011-03-23 02:40

The following plots show the partial evolution of physical quantities in the Fukushima Daiichi reactors #1, #2, and #3, during a the march/2011 incident. Note that the incident started on 2011-03-11 (friday), two days before the start of the plots.

Plots

Reactor 1

plot: reactor 1

Reactor 2

plot: reactor 2

Reactor 3

plot: reactor 3

Quantities:

Water level

This quantity is the water level, inside the (inner) reactor pressure vessel, in millimeters, measured from the top of the fuel elements. Negative values mean that the fuel is partly out of the water.

Core pressure

This quantity is the pressure in the inner reactor pressure vessel, in kilopascals (kPa). A value of zero means the same as outside air pressure. Note that 100 kPa is aproximately 1 bar (one atmosphere).

Drywell pressure

This quantity is the pressure (kPa) in the "drywell", the outer steel container that surrounds the reactor. A value of zero means the same as outside air pressure.

Suppression container pressure

This quantity is the pressure (kPa) in the suppression container, the toroidal (donut-shaped) chamber below the drywell container. A value of zero means the same as outside air pressure.

Core temperature

This quantity is the temperature (Celsius) at the bottom of the reactor's (inner) pressure vessel. Note:The value is multiplied by 10 for clarity.

Data sources

Water level and pressure

The water level and pressure data comes from the PDF document titled 'Condition of the plants of the unit 1-3 at FI site', fetched from the Nuclear Information and Resource Service site on 2011-03-22. That site says

Here is a document on the condition of Units 1, 2 & 3 from March 13-17, showing water levels and containment pressure, obtained through Citizens' Nuclear Information Center in Tokyo.

The data from that document was reformatted by hand into the text file.

The gaps in the plots are data points that were either blank or marked "d/s" in the original document. The document covers only the period from 1011-03-13 to 2011-03-17. For further information please contact the document authors.

Temperature

The temperature readings were obtained from a scanned worksheet presumably prepared by TEPCO, covering the period from 2011-03-19 06:30 to 2011-03-22 15:30. The data was entered by hand to a separate text file.

Plotting

The plots were created by a gnuplot-based Linux shell script.

Disclaimer

IMORTANT: These plots, scripts, and data files are provided "as is", for the reader's convenience, with no guarantee whatsoever. There may be errors in the original document and/or in my processing of it. This page is not an official document of the State University of Campinas (UNICAMP). Neither me nor UNICAMP should be held responsible for any damages that may result from the use of this information. Corrections and suggestions are welcome.

Last edited on 2011-03-23 03:07:22 by stolfi