Abstract
A MELCOR model of the Fukushima Daiichi unit 2 accident
was created in order to get a better understanding of the
event and to improve severe accident modeling methods.
The measured pressure and water level could be reproduced
relatively well with the calculation. This required
adjusting the RCIC system flow rates and containment leak
area so that a good match to the measurements is
achieved. Modeling of gradual flooding of the torus room
with water that originated from the tsunami was necessary
for a satisfactory reproduction of the measured
containment pressure. The reactor lower head did not fail
in this calculation, and all the fuel remained in the
RPV. 13 % of the fuel was relocated from the core area,
and all the fuel rods lost their integrity, releasing at
least some volatile radionuclides. According to the
calculation, about 90 % of noble gas inventory and about
0.08 % of cesium inventory was released to the
environment. The release started 78 h after the
earthquake, and a second release peak came at 90 h.
Uncertainties in the calculation are very large because
there is scarce public data available about the Fukushima
power plant and because it is not yet possible to inspect
the status of the reactor and the containment.
Uncertainty in the calculated cesium release is larger
than factor of ten.
Original language | English |
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Title of host publication | Proceedings [Elektronski vir] / 22nd International Conference Nuclear Energy for New Europe |
Subtitle of host publication | NENE 2013, Bled, September 9-12 |
Editors | Leon Cizelj, Matjaž Leskovar, Mitja Uršič |
Number of pages | 9 |
ISBN (Electronic) | 978-961-6207-36-2 |
Publication status | Published - 2013 |
MoE publication type | A4 Article in a conference publication |
Event | 22nd International Conference Nuclear Energy for New Europe, NENE 2013 - Bled, Slovenia Duration: 9 Sep 2013 → 12 Sep 2013 |
Conference
Conference | 22nd International Conference Nuclear Energy for New Europe, NENE 2013 |
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Abbreviated title | NENE 2013 |
Country | Slovenia |
City | Bled |
Period | 9/09/13 → 12/09/13 |
Keywords
- nuclear safety
- severe accidents
- Fukushima
- MELCOR