1. Severe accidents of nuclear power
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
plants in Europe: possible
consequences and mapping of risk
Petra SEIBERT1,
Delia ARNOLD1,4, Gabriele MRAZ3, Nikolaus ARNOLD2, Klaus GUFLER2,
Helga KROMP-KOLB1, Wolfgang KROMP2, Philipp SUTTER3, Antonia
WENISCH3
1Institute of Meteorology, BOKU, Austria
2Institute for Security and Risk Sciences, BOKU, Austria
3Austrian Institute of Ecology, Austria
4Institute of Energy Technologies (INTE),
Technical University of Catalonia (UPC), Barcelona,Spain
1/14

2. The flexRISK project
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
 2009-2012, interdisciplinary, 3 Austrian institutions
 Main aims:
 demonstrate the overall geographical distribution of the risk caused
by severe accidents in nuclear power plants in Europe
 Show the contribution of different nuclear power plants according to
type and geographical location
 study the effects of phase-out scenarios
 Methods
 Collect data for all 228 NPPs in Europe + Akkuyu (TR), Bushehr
 Identify severe accident with inventories, release fractions, release
frequencies for each plant
 Perform Europe-wide dispersion & dose calculations for 2788 cases
 Produce single-case maps and various aggregated risk parameters
2/14

3. Accident data
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Limited data available (nuclear industry business secrets)
 Grouping of NPPs into similar types
 13 groups for release shapes (duration and effective height)
 24 groups for release fractions (of inventory being released)
 Where available (public), plant-specific data used
 Different types of severe accidents considered, e.g.
 Steam generator tube ruptures (late)
 Core melt accident with failure of containment isolation (early)
 Interfacing Systems Loss-Of-Coolant Accident (early)
 Core power excursion – RBMK (early)
 Loss of carbon dioxide coolant – GCR (late)
3/14

4. Release fractions & accident frequency
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Fukushima Chernobyl
Older designs with
!! per unit !! extreme accidents
and moderate to high
frequencies
Low frequencies,
r y 1 yc neuqe t ned cc A
moderate releases
f i
 Most accidents considered release 10-30% of
inventory of volatile nuclides, some up to ca. 60%
/ (
4/14  Frequencies span 5 orders of magnitude!

5. Dispersion calculations
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
 Lagrangian dispersion model
FLEXPART, dry and wet
deposition
 ERA-Interim 70 km meteo input
data for 1995, 2000-2009,
3-hourly
 2788 cases (real weather
situations)
 Output grids: fine (10 km),
coarse (1 degree), 3 h
 Calculate only source-receptor
sensitivity, scale with source
term for each nuclide in
postprocessing
Fine output domain
 2 weeks in VSC-2 Vienna
supercomputer, 2.5 Terabyte Coarse output domain
output (highly compressed) Calculation domain
5/14

6. Ground contamination & concentration examples
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
6/14

7. Example of risk: Iodine prophylaxis for children
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Intervention level for administering
iodine tables in Austria (children):
10 mSv (7 day inhalation dose)
Risk parameter shown:
Weather-related probability of
exceeding the intervention level for
a given NPP (Philippsburg 2,
release fraction for iodine is 20%)
Probabililty > 1% from France to
Western Poland, Northern Austria
> 1 o/oo even further away
But many countries prepared well
only within 30 to 100 km!
7/14

8. Geographical distribution of total risk
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Risk parameter shown:
Probability of exceeding the 37
kBq/m2 Cs-137 IAEA threshold
Sum over all NPPs active
Met. frequency x frequency of
accident in each NPP unit
Low contamination:
Determined by dominant wind
directions and distribution of
plants
Strong W-E gradient:
1e-7 Portugal
1e-6 Western Coast
1e-5 Western Central Europe
1e-4 Eastern Central Europe
8/14

9. Geographical distribution of total risk
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Heavy contamination
(resettlement after
Chernobyl)
Dominated by sites and their
accident severity & frequency
Heaviest maximum:
Temelin-Dukovany-Bohunice-
Mochovce-Paks-Krsko region
Ukraine and Russia
Also near RBMK sites
But large parts of Europe are
under risk!
9/14

10. Risk originator for Austria – high contamination
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Risk received by Austria from …
Contribution of each NPP country to Austria’s risk of receiving a
contamination over 1480 kBq/m2 on the part of the country
indicated in the box-and-whisker
Risk is dominated by CZ,
but for big areas Germany advances from rank 4 to rank 2
Chernobyl (UA) could have hit us with 1500 instead of 100 kBq/m2 !!
10/14

11. Sensitivity to accident frequency
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Same as previous map, but low range of accident frequencies
halved in log space (1E-9 to 1E-5 mapped on 1E-7 to 1E-5)
Risk in Western and Eastern Europe now more similar
11/14

12. Effects of phasing-out scenarios
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
S 3 / S 1:
2011 shutdowns in
Germany and UK
plus all pre-1980 units
High contamination:
Large reductions in
Switzerland, all of
Germany, W Austria
and UK, Scandinavia !
Not much change for
Eastern Austria (not plants
in the East phased out)
12/14

13. Conclusions
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
1. Risk pattern reflects site density, NPP type and climate
Maxima: E. Central Europe, parts of FR, around large sites in UA and RU
Minima on N European Atlantic coasts and in Mediterranean
2. Substantial consequences (intervention measures) possible for distances
up to 500-1000 km, more frequent / severe for up to 100-300 km
That’s in agreement with Chernobyl experiences, but many didn’t want to
fully face these consequences
3. Emergency planning presently focussing on too small areas.
In reality, almost all of Europe should be prepared for nuclear disaster
4. Risk distribution depends on level of damage: high damage is more
concentrated, low or moderate damage spreads over long distance.
5. Thus, regional phase-out policy is effective for reducing or even
eliminating high damage
6. Risk distribution also depends strongly on accident frequency, but this
parameter is highly uncertain
13/14

14. Thank you!
Flexible Werkzeuge zur Abschätzung des nuklearen Risikos in Europa
Extensive project web site: flexrisk.boku.ac.at
14/14