Home Uncategorized Reading and Answering 3

Uncategorized

Reading and Answering 3

The Russian nuclear submarine K27 was damaged and intentionally sunk with its nuclear fuel aboard in Stepovogo Bay in 1981, a region of the Arctic very near to Norway. Since then, the Norwegians have been concerned because it theoretically could one day cause a criticality accident that would result in atmospheric transport of radioactive materials across Norway. To assess the threat, a team of Norwegian scientist modeled “worst case” scenarios, and assessed the potential radiological risk to Norwegians.

Read their paper:

Atmospheric transport of radioactive debris to Norway in case of a hypothetical accident related to the recovery of the Russian submarine K-27. Journal of Environmental Radioactivity 151 (2016) 404e416

Answer the following questions:

1. Describe the SNAP Model and what it does.

2. What is the effect of particle size on the SNAP Model?

3. What type of meteorological data are required to conduct the analysis?

4. How was the amount of radioactivity in the submarines reactors estimated?

5. What criterion were used to simulate a “worst case” scenario?

6. How did the worst case scenario compare with the radioactivity deposited on Norway by the Chernobyl accident?

7. What is your opinion about the usefulness of the SNAP Model estimating environmental consequences of a nuclear accident?

Radiation biology environmental

lable at ScienceDirect

Journal of Environmental Radioactivity 151 (2016) 404e416

Contents lists avai

Journal of Environmental Radioactivity

journal homepage: www.elsevier .com/locate / jenvrad

Atmospheric transport of radioactive debris to Norway in case of a
hypothetical accident related to the recovery of the Russian submarine
K-27

Jerzy Bartnicki a, d, *, Ingar Amundsen b, Justin Brown b, d, Ali Hosseini b, d, Øystein Hov a, d,
Hilde Haakenstad a, Heiko Klein a, d, Ole Christian Lind c, d, Brit Salbu c, d,
Cato C. Szacinski Wendel c, d, Martin Album Ytre-Eide b, d

a Norwegian Meteorological Institute, P.O. Box 43 Blindern, NO-0313 Oslo, Norway
b Norwegian Radiation Protection Authority, Grini Næringspark 13, NO-1361 Østerås, Norway
c Norwegian University of Life Sciences, P.O. Box 5003, NO-1432 Ås, Norway
d Centre for Environmental Radioactivity, P.O. Box 5003, NO-1432 Ås, Norway

a r t i c l e i n f o

Article history:
Received 12 December 2014
Received in revised form
20 February 2015
Accepted 21 February 2015
Available online 21 March 2015

Keywords:
Hypothetical nuclear submarine reactor
accident
Risk assessment
Atmospheric dispersion
Threat to Norway

* Corresponding author. Norwegian Meteorologica
ern, NO-0313 Oslo, Norway. Tel.: þ47 22 963000.

E-mail address: jerzy.bartnicki@met.no (J. Bartnick

http://dx.doi.org/10.1016/j.jenvrad.2015.02.025
0265-931X/© 2015 The Authors. Published by Elsevier

a b s t r a c t

The Russian nuclear submarine K-27 suffered a loss of coolant accident in 1968 and with nuclear fuel in
both reactors it was scuttled in 1981 in the outer part of Stepovogo Bay located on the eastern coast of
Novaya Zemlya. The inventory of spent nuclear fuel on board the submarine is of concern because it
represents a potential source of radioactive contamination of the Kara Sea and a criticality accident with
potential for long-range atmospheric transport of radioactive particles cannot be ruled out. To address
these concerns and to provide a better basis for evaluating possible radiological impacts of potential
releases in case a salvage operation is initiated, we assessed the atmospheric transport of radionuclides
and deposition in Norway from a hypothetical criticality accident on board the K-27. To achieve this, a
long term (33 years) meteorological database has been prepared and used for selection of the worst case
meteorological scenarios for each of three selected locations of the potential accident. Next, the
dispersion model SNAP was run with the source term for the worst-case accident scenario and selected
meteorological scenarios. The results showed predictions to be very sensitive to the estimation of the
source term for the worst-case accident and especially to the sizes and densities of released radioactive
particles. The results indicated that a large area of Norway could be affected, but that the deposition in
Northern Norway would be considerably higher than in other areas of the country. The simulations
showed that deposition from the worst-case scenario of a hypothetical K-27 accident would be at least
two orders of magnitude lower than the deposition observed in Norway following the Chernobyl
accident.
© 2015 The Authors. Published by Elsevier

Ltd. This is an open access article u

nder the CC BY-NC-ND

license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

1. Introduction

In September 1981, the nuclear submarine K-27 was scuttled in
very shallow waters (depth of just 30 m) in the outer part of Ste-
povogo Bay on the eastern coast of Novaya Zemlya (72�310N,
55�300E) where it lies today. The submarine K-27 is one of several
objects with spent nuclear fuel (SNF) which have been dumped in

l Institute, P.O. Box 43 Blind-

i).

Ltd. This is an open access article u

the Kara Sea over time. K-27 contains two liquid metal reactors
(LMRs) of 70 MW maximum thermal power each, which used
PbeBi as a coolant. The reactors were loaded with 180 kg of U-235.
Concerns have been expressed by various parties with regards to
the radiological consequences of potential radionuclide releases
from the submarine and in particular potential releases if a salvage
operation is initiated.

There are four scenarios that have been envisaged which could
result in potential releases from the submarine when subjected to
different, hypothetical management options and/or handling
stages. These include: (i) potential leakage or accident associated
with the so called “zero alternative”, when no action is taken. The

nder the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Delta:1_given name

Delta:1_surname

Delta:1_given name

Delta:1_surname

Delta:1_given name

Delta:1_surname

Delta:1_given name

Delta:1_surname

Delta:1_given name

Delta:1_surname

Delta:1_given name

http://creativecommons.org/licenses/by-nc-nd/4.—0/

mailto:jerzy.bartnicki@met.no

http://crossmark.crossref.org/dialog/?doi=10.1016/j.jenvrad.2015.02.025&domain=pdf

www.sciencedirect.com/science/journal/0265931X

http://www.elsevier.com/locate/jenvrad

http://dx.doi.org/10.1016/j.jenvrad.2015.02.025

http://creativecommons.org/licenses/by-nc-nd/4.—0/

http://dx.doi.org/10.1016/j.jenvrad.2015.02.025

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 405

submarine remains at its current location and any release would
occur at a depth of 20e30 m below the sea surface. In this case
most of the available radionuclides would be released directly into
the water, (ii) a potential accident during the lifting of the sub-
marine to the surface. Depending on the depth, the major part of
the available radionuclides would be released either into the
water or directly into the air. (iii) an accident during trans-
portation of the submarine from Novaya Zemlya to its probable
final destination at Gremikha Bay e one of the sites where
radioactive wastes related to the Russian Northern Fleet activities
have been accumulated. (iv) a potential accident at the final
destination at Gremikha Bay. The hypothetical accidents in alter-
natives (iii) and (iv) have the potential to occur on the water
surface or on shore with most of the radionuclides released
directly into the air.

In our study, we only take into account the last three scenarios
as all of these involve direct releases of radionuclides into the air.
There is also a possibility for an accident to occur under water. At
locations close to the surface, this would create a secondary release
of radionuclides into the air, but the magnitude of such a release is
assumed to be much lower than in the case of a direct release into
the air.

For all the alternatives mentioned above, a risk of an accident as
a consequence of an uncontrolled chain reaction event cannot be
ruled out. Such a hypothetical accident might pose a risk of
contamination occurring over Norwegian territory and thus, should
be analysed from different perspectives. Here, we focus on the
worst case meteorological scenario for Norway as a receptor, but
the same approach can be applied for other receptors e.g. Scandi-
navian countries and Russia. The main goal of this study was to
analyse atmospheric transport to and deposition of radionuclides
over Norwegian territory, in case of a nuclear accident related to
lifting and transporting the K-27 submarine. Preliminary results of
the study have been described in Bartnicki et al. (2013). Here we
present the final results.

2. Material and methods

The SNAP (Severe Nuclear Accident Program) model (Bartnicki
et al., 2011) was the main tool for all dispersion simulations pre-
sented here. This Lagrangian particle dispersion model is currently
operational at the Norwegian Meteorological Institute, MET, for
emergency situations.

The estimation of the atmospheric transport to and deposition
of radionuclides over Norway released in a hypothetical K-27 ac-
cident has been performed in six steps. The first step was a prep-
aration of a large database with meteorological data required as
input for the SNAP model, for a period of 33 years (1980e2012).
This meteorological database is available for a domain covering an
area of 4400 km � 2200 km which includes both the entire Nor-
wegian territory and the region of Novaya Zemlya where the K-27
submarine is currently located.

The second step involved the development of a preliminary
source term for potential accidents which could be used by the
dispersion model. Three locations for potential accidents with
resultant releases of radioactivity to the environment were
assumed: 1) in the present location of K-27 at Novaya Zemlya, 2) on
the way to Murmansk and 3) in Gremikha Bay as the final
destination.

In the third step, the SNAP model was run with the preliminary
source term starting twice a day for the entire 33 years period with
meteorological data. As a result of the model simulations, surface
concentration fields and deposition fields were calculated for
selected radioactive particles for the entire model area.

Based on these results, in the fourth step, the worst case
meteorological scenarios were selected for potential accidents in
each of the three locations. Theywere selected based on the highest
levels of deposition on Norwegian territory. In addition, statistical
analysis was performed for the 33-year period in this step. This
analysis included calculation and discussion of the probability of
arrival to an arbitrary place in Norway and the calculation of the
shortest arrival time.

The fifth step focussed on development of the final source term
corresponding to the K-27 accident scenario involving a hypo-
thetical uncontrolled chain reaction with 1020 fissions and the
most recent estimates of residual activities for the reactors on
board the nuclear submarine K-27 (NRPA, in preparation). The
final source term was estimated based on experiences from the
Chernobyl accident and includes different categories (groups) of
radioactive particles and iodine gases. Particle densities were
calculated from physical data given in Lide (2005) and under the
assumption of a UO2Be composition of the reactor fuel (IAEA,
1997).

In the sixth and final step of the study, the SNAP model was run
with the final source term for selected worst case meteorological
scenarios for all three locations of the potential accident. The re-
sults of these runs are presented and discussed here.

2.1. SNAP model

The SNAP model is a Lagrangian particle model and has been
developed at MET for simulating atmospheric dispersion of radio-
active debris, first from nuclear accidents and then from nuclear
explosions. As is the case for many other models, the development
of SNAP started after the Chernobyl accident which occurred in
April 1986. The first, preliminary version of SNAP was developed in
1994 and became fully operational at MET in December 1995
(Saltbones, 1995). It was tested against tracer measurements in the
European Tracer Experiment (ETEX) (Saltbones et al., 1996) and
then improved (Bartnicki and Saltbones, 1996). The SNAP model
was compared with other models (Maryon et al., 1996) and tested
on measurements available from the tracer experiment e ATMES
(Saltbones et al., 1998).

The basic concept of a Lagrangian particle model is rather simple
in principle. The emitted mass of radioactive debris is distributed
among a large number of model particles. After the release, each
model particle carries a given mass of selected pollutant which can
be in the form of gas, aerosol or particulatematter. Amodel particle,
in this approach, is given an abstract mathematical definition,
rather than providing a definition for a physical air parcel con-
taining a given pollutant. The model particle is used in SNAP as a
vehicle to carry the information about the pollutant emitted from
the source. It is not given a definite size and cannot be subdivided
or split into parts. On the other hand, the mass carried by the
particle can be subdivided and partly removed during the
transport.

The plume rise in the SNAP model is not explicitly calculated,
because for long range atmospheric transport it is assumed that the
plume rise effect is already included in the initial distribution of the
radioactive cloud after the accident or explosion and especially in
the vertical range. This is a typical approach for most of the long
range transport models.

In the early versions of the SNAP model, only aerosols (diameter
below 1 mm particles) were taken into account in the model
equations. However, measurements performed by the Norwegian
University of Life Sciences after the Chernobyl accident, showed
that large particles (mm) to fragments were deposited close to the
site, while much smaller radioactive particles (in the order of
1e20 mm), so called ‘hot particles’, could also be transported for

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416406

long distances and end up in Norway 2000 km from the release site
(Salbu et al., 2001). Later, it has been observed that radioactive
particles are released following all types of severe nuclear events
(Salbu and Skipperud, 2009; Salbu and Lind, 2011; Wendel et al.,
2013). Therefore, parameterization of particle properties (arbi-
trary diameter, composition and density) was introduced into the
SNAP model and this model version was applied to re-simulate the
Chernobyl accident (Bartnicki et al., 2003). This version was also
applied for simulating the potential release from Kola, focussing on
the release of radioactive particles of different size and density
(Bartnicki et al., 2005).

Introduction of arbitrary particles into the SNAP equationsmade
it possible to create a model version for nuclear explosions
(Saltbones et al., 2003). In the current model version (Bartnicki
et al., 2011), atmospheric dispersion from both nuclear accidents
and nuclear explosions can be simulated, as well as, atmospheric
transport and deposition of radioactive particles of arbitrary size
and density. This model version has been used for all the compu-
tations presented and discussed here.

2.2. Meteorological database

The European Medium Range Weather Forecast Centre
(ECMWF) in Reading, UK, is a valuable source of not only meteo-
rological forecasts, but of long term historical meteorological data
as well. For the specific Norwegian needs, a historical meteoro-
logical database NORA10 was developed first (Reistad et al., 2011)
based on ERA40 e a historical database developed at ECMWF
(Uppala et al., 2005). For the present study, a new improved
meteorological database called NORA10-EI has been prepared and
used. The database NORA10-EI has been produced by dynamical
downscaling of the ERA-Interim (Dee et al., 2011) reanalysis with
the HIRLAM numerical weather prediction model (Und�en et al.,
2002). Its domain includes the north-eastern North Atlantic and
the Nordic countries. The horizontal resolution is approximately
11 km. Surface fields are stored every hour, while model level fields
are stored every third hour. This database covers the period January
1980 and up to December 2012. It has been used as a meteoro-
logical input for all SNAP runs in this study.

2.3. Selection procedure

It is difficult to formulate a set of objective criteria for selecting
the worst case meteorological scenario for the atmospheric trans-
port of radionuclides to Norway. Considering the problem from the
environmental perspective, maximum deposition over Norwegian
territory has been used as the main criterion in selecting the worst
case scenario.

Three locations of a hypothetical K-27 accident were taken into
account: 1) the initial e present location of K-27, 2) the location on
the way to Murmansk region and 3) the final location corre-
sponding to a reception point at Gremikha Bay. Amapwith all three
locations of the potential accidents is shown in Fig. 1.

The selection of the worst case meteorological scenario was
made by performing SNAPmodel runs for a given accident scenario
for the entire considered period. The transport of the recovered K-
27 over the Barents Seawould be possible only during a two-month
window (August and September) because of difficult meteorolog-
ical conditions and extensive presence of sea ice in the remaining
months of the year. Therefore, for the accidents at all locations,
SNAP was run twice a day, but only for August and September, each
year.

The source-term of the worst case accidents at the different
locations is highly uncertain. To separate the meteorological vari-
ability from the source term uncertainties, a simplified source term

has been selected for the identification of the worst meteorological
case. This simplified source-term defined in Table 1 assumed
release of 137Cs particles with diameter 0.55 mm and density
2.3 g cm�3. The size and density are taken from ARGOS database
(Hoe et al., 2002; Bartnicki et al., 2011). ARGOS is a decision support
system used by radiation protection authorities in Scandinavian
countries: Norway, Denmark Sweden and Finland.

The deposition of 137Cs to Norwegian territory has been used as
a pre-selection criterion for the worst cases for each accident
location. The top cases of the pre-selection were then inspected
visually for the final selection of the worst case meteorological
scenarios.

2.4. Worst case source term for K-27 accident

The simplified preliminary source term was only used for the
model runs in the selection procedure. A more advanced and
complicated source term was developed for the final SNAP runs
with the selected worst case meteorological scenarios. This source
term was based on the inventory which has been developed
through considering, among other things, the reactor design and its
existing barriers (furfural, bitumen).

For the compilation of the potential source term it is necessary
to estimate the residual activities in the reactor of the submarine
located in different places within the vessel and related to different
radionuclides. There are several estimates available from the past
(IAEA, 1997; Lavkovsky, 1999), but in the present work we have
used the most updated estimates of residual activities for the K-27
reactor by 2013, as shown in Table 2. More details concerning this
source term are provided in NRPA (in preparation).

Degradation of the reactors with time may lead to an event
involving a Spontaneous Chain Reaction (SCR). There are two
possible conditions for an SCR to occur: (1) water penetration into
the core, and (2) relative displacement of fuel resulting in reduction
in the compensation capacity of the Control and Protection System
(CPS) operating elements. The reactor compartment of K-27 was
sealed before dumping to reduce risk of releases of radionuclides in
the marine environment. In addition, measures were taken to
prevent displacement of fuel and infiltration of water through in-
jection of preservatives (e.g. furfural, bitumen) into the free spaces
of the reactor compartments.

The specification of the source term for the final model runs was
developed with all the above facts in mind. In the final model runs,
utilizing the worst case meteorological scenarios, the same source
term was used for all three locations of the potential accident. Ac-
tivities for the present study were calculated at the time of release
assuming various release fractions as considered by NRPA (in
preparation), plus the activity generated during a potential criti-
cality event.

Four particle classes with different densities and sizes and
iodine gas were taken into account in determining the source term
for the final model runs. Specification of the source term for four
classes of particles and for iodine gas is shown in Table 3.

In the SNAP model, the properties of radioactive particles (U
matrix) and gases are included in the so-called “model particles”
explained in Section 2.1. The number of model particles for
simulating the source term, described in Table 3, can be reduced,
mainly because of similarities between different groups of
radioactive particles. The specification of the model particles used
in the SNAP runs for the worst case scenarios is presented in
Table 4.

Altogether, 30 model particles were used in the SNAP runs with
the final source term. These model particles represent the real
particles listed in Table 3. We assumed a release time of 1 h and a
release height in the range of 0e100 m for this accident.

Fig. 1. Three accident locations which have been taken into account in the selection procedure: A) the initial e present location of K-27, B) the location on the way to Murmansk
region and C) the final location at Gremikha Bay.

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 407

3. Results and discussion

The extensive meteorological database which was established
within this study has been used for the selection of the worst case
meteorological scenarios and statistical analysis of the results and
especially for the probability maps of arrival to Norway (see Section
3.2).

3.1. Selection of the worst case meteorological scenarios

An important element of the selection procedure is the choice of
the criterion or criteria for the worst case. This is a challenging
problem which can be approached from different perspectives.

Under normal conditions, wet deposition is the most effective
mechanism for significant deposition, even at substantial distances
from the original source (Wright et al., 1997). Therefore, wet
meteorological situations need to be accounted for and especially
for those situations involving long-distance atmospheric transport
without precipitation on route followed by heavy precipitation at
the arrival point.

Table 1
Specification of the preliminary source term used for the selection procedure.

Parameter Value

Initial location 72.5N 55.5E
Intermediate location 69.5N, 47.0E
Final location 68.04N, 39.33E
Radionuclide Cs-137 in the particle form
Particle size 0.55 mm
Particle density 2.3 g cm�3

Release rate 2.0 � 1011 Bq s�1
Release period 12 h
Vertical range 0e500 m

Table 2
The most recent estimates of residual activities for the reactors on board the nuclear
submarine K-27. Reference year 2013.

Activity source Main radionuclides Activity (TBq)

Fission products 137Cs þ 137mBa, 90SR þ 90Y 270
Control rods 152Eu, 154Eu 40
Reactor shell constructions 63Ni, 60Co 11
Actinides 238Pu, 239Pu, 240Pu, 241Pu, 241Am 4.6
Tritium 3H 34

In this study focus has been placed upon the potential for
environmental impacts, including impacts on food-chains leading
to man. Thus, average deposition over Norwegian territory was
chosen as the worst case criterion in the selection procedure. Only
137Cs particles were released in the preliminary source term. These
particles are among the smallest and lightest, being subject to
moderate wet-deposition. The 137Cs is also a well-studied isotope
and has been observed to undergo long-range atmospheric
transport.

From all model runs we selected those contributing to non-zero
deposition to Norwegian territory. By dividing the number of
contributing runs by the number of total runs we could calculate
the percentage of meteorological situations with transport to
Norway from the accident locations. The number of cases with
deposition above zero decreased with the distance between the
release location and Norway. For releases at the initial location,
during the transport and at the final destination, the probabilities

Table 3
Source term for the worst case accident scenario for K-27 submarine which includes
a hypothetical SCR event.

Component Half-life Total release (Bq)

UO2Be, density ¼ 2.1 g cm�3, size classes: 0.1, 0.5, 1.0, 5.0, 10.0, 20.0, 50.0,
100.0 mm

137Cs 30.17 years 7.1 � 1012
90Sr 28.8 years 6.2 � 1012
238Pu No decay 1.6 � 1011

Bitumen, density ¼ 1 g cm�3, size classes: 0.1, 0.5, 1.0, 5.0, 10.0, 20.0, 50.0,
100.0 mm

137Cs 30.17 years 4.4 � 1011
90Sr 28.8 years 3.9 � 1011
238Pu þ 240Pu No decay 1.0 � 1010
131I 8.04 days 1.4 � 1011

Metal coolant, density ¼ 10.5 g cm�3, size classes: 0.1, 0.5, 1.0, 5.0, 10.0, 20.0,
50.0, 100.0 mm

137Cs 30.17 years 4.4 � 1011
90Sr 28.8 years 3.9 � 1011
238Pu no decay 1.0 � 1010

Ru-106, density ¼ 3.3 g cm�3, size classes: 0.1, 0.5, 1.0, 5.0, 10.0, 20.0 mm
106Ru 1.02 years 1.9 � 109

I-131, gas, density ¼ 0.0113 g cm�3
131I 8.04 days 1.4 � 1011
133I 20.04 h 5.2 � 1012

Table 4
Specification of the model particles representing the real particles and gases for the worst case SNAPmodel runs. The symbol “C” indicates the type of themodel particle used
in the simulations. Decay means assumed decay half-life.

Group Density (g cm�3) Radius (mm) Release (Bq) Decay (h)

0.1 0.5 1.0 5.0 10 20 50 100

UO2Be 2.1 C C C C C C C C 1.35 � 1013 No
Bitumen 1.0 C C C C C C C C 9.8 � 1011 No
Metal 10.5 C C C C C C 8.4 � 1011 No
106Ru 3.3 C C C C C C 1.9 � 109 No
131I 0.0113 C 1.4 � 1011 192.96
133I 0.0113 C 5.2 � 1012 20.04

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416408

of reaching Norwegian territory were 17%, 25% and 37%, respec-
tively. Also, the average deposition over Norway was clearly
dependent upon the distance from the release location, with the
largest depositions occurring for the source located at the final
destination.

The worst meteorological cases for hypothetical accidents are
presented as maps of total 137Cs deposition in Fig. 2. For the
hypothetical accident at the initial location, the worst case
meteorological scenario was found for a release starting on 26th
August 1998 at 00 UTC. For the hypothetical accident during
transport and at the final destination, the worst case meteoro-
logical scenario was found for a release starting on 7th September
1986 at 12 UTC and on 22nd September 2004 at 12 UTC,
respectively. These selected meteorological situations were used
for SNAP runs with the worst case accident scenario discussed in
Section 3.3.

The deposition pattern is similar for initial and final accident
locations and also similar, but with some small differences, for the
accident location during transport or ‘on theway’. In all three cases,
there is a clear initial transport of radionuclides to the west, before
the plume trajectory turns to the south and even to the east during
the late stage of transport. The main difference for the accident
location ‘on theway’ is the visible addition of direct transport to the
east from the source.

For all accident locations, a relatively high deposition level can
be noticed in the most northern part of Norway. Elevated de-
positions can be also observed in central Norway. Deposition levels
in southern Norway are much lower than those in northern
Norway.

The selected meteorological situations described above were
used for the model runs with the realistic, worst case accident
scenario discussed in Section 3.3.

3.2. Probability maps

The probability of arrival is an important piece of information
for risk estimation. The probability of arrival to a given model grid
was calculated as the ratio of model runs with non-zero deposition
in a given grid to the total number of model runs. The maps of
probability of arrival to each model grid are shown in Fig. 3 for all
three accident locations.

The probability of arrival to Norway is clearly higher for the
hypothetical accident at the final destination in Gremikha Bay than
for accidents at the two other locations. The probability of arrival
has a maximum in the very northern part of Norway falling within
the ranges 10e15%, 15e25% (but closer to 15%) and 15e25% (but
closer to 25%) for the accident in the initial location, ‘on the way’
and at the final destination, respectively. These probabilities are
much lower in the model grids located in southern Norway, below
1% for the accident at the initial location and below 3% for the ac-
cident at the remaining locations.

3.3. Worst case scenarios with the final source term

The SNAP model was run with the source term for the realistic,
worst-case accident scenario described in Section 2.4 and for all
three selected worst case meteorological scenarios.

Limited information was available in relation to a realistic
radionuclide distribution among different particle size classes and a
particle distribution pattern for the worst case source term.
Therefore, an equal distribution was assumed for each of the size
classes used in the SNAP runs. This assumption could lead to an
overestimation of the contribution of large particles to the depo-
sition, while this potential overestimation will be limited to short
range transport only.

The heat generated during an explosion would have the po-
tential to lift radioactive pollutants into the air. Usually the upper
limit for vertical distribution of pollutants in such cases is the top of
the mixing layer. For the chosen locations and the time of the year
when the potential accidents could occur, a typical height of the
mixing layer would be about 100 m. Therefore, we have assumed
the release to be in the range of 0e100 m, corresponding to a
typical mixing layer with a height of 100 m.

The horizontal spread of radionuclides during the release was
assumed to occur in a cylinder with a radius of 25 m. There is some
uncertainty in this assumption, but for a long range transport, as
exemplified by our case, the calculated levels of deposition are
rather insensitive to this parameter.

The results of the model simulations for the worst case accident
scenario and worst case meteorological scenarios are shown in
Fig. 4 for all three locations of the hypothetical accident. This figure
shows the total deposition after 96 h from the accident start. Total
refers to the sum of wet and dry deposition from all considered
particle classes.

In case of the accident at the initial location, two regions situ-
ated in the northern part of Norwaywould be affected. The absolute
maximum values of total deposition for this scenario were seen in
the northern part of Finnmark, falling in the range of 10e30 Bqm�2.
The range of total deposition in the region between Nordland and
Troms was slightly lower: 3e10 Bq m�2. The rest of Norway was
practically unaffected by radioactive contamination in this
scenario.

The shape of the total deposition was predicted to be slightly
different in the case of an accident location ‘on the way’, but also, in
this case, the absolutemaximumwas observed in northern Norway.
However, the maximum of total deposition in the northern part of
Finnmark was close to 300 Bq m�2, much higher than in the pre-
vious case. Also in this scenario, the central and southern parts of
Norway were not affected by the accident.

The Norwegian area covered by the deposition in case of the
accident location in Gremikha Bay was predicted to be significantly
larger than in the two previous cases. The local maxima of total
deposition were visible again in the north, affecting the three

Fig. 2. Maps of total deposition of 137Cs in the worst case meteorological scenarios, 96 h after the accident start. Accident at initial location e top, accident on the way e middle and
accident at the final destination e bottom. Units: Bq m�2.

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 409

counties: Finnmark, Troms and Nordland. In addition, several
counties in central Norway (Nord-Trøndelag, Sør-Trøndelag, Møre
and Romsdal, Oppland and Hedmark) were also affected. The levels
of local maxima of total deposition were 100e300 Bq m�2 in the
north and 10e30 Bqm�2 in central Norway. This was theworst case
of combinedmeteorological and accident scenario among the three
locations of a potential accident.

Comparison of three deposition maps shown in Fig. 4 clearly
indicates that in any case it is the very northern part of Norway that
would receive the highest deposition.

3.4. Dry versus wet deposition

In general, wet deposition is much more effective in removing
elements from the air than dry deposition, conditional, of course,

Fig. 3. Maps of probability of arrival (in %) to each model grid from releases: at initial location e top, on the way to Gremikha Bay e in the middle and at the final destination e
bottom.

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416410

on there being precipitation during transport from the source to the
receptor. The wet deposition parameterization developed by
Baklanov and Sørensen (2001) is implemented in the SNAP model.
In this parameterizationwashout coefficients are dependent on the
particle size, precipitation intensity and precipitation type. A
comparison of dry and wet deposition after 96 h from the accident
start, for the worst case meteorological scenario with Gremikha as
the accident location, and final source term is shown in Fig. 5.

Except for a small area on the North Sea, wet deposition dominated
over dry deposition everywhere, especially in northern and central
Norway.

3.5. Depositions from individual components

Total deposition from all components together was presented
and discussed in the previous section. Here we will discuss the

Fig. 4. Maps of total deposition (wet þ dry and from all components) from SNAP runs with the final source term specified in Table 4 and worst case meteorological scenario for
accident at the initial destination (top), on the way (middle) and at the final destination (bottom). Units: Bq m�2.

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 411

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416412

individual impact of all 30 model components included in Table 4.
The complete results of the model run for all individual compo-
nents are not shown due to limited space, but can be found in
Bartnicki et al. (2013).

Among the four groups of particles which were included in the
SNAP run for the worst case scenario, the total release was highest
for the UO2Be group, falling two orders of magnitude above the
releases for the two next groups (Bitumen and Metal). The total
release of the last group (106Ru) was again much lower, more than
four orders of magnitude lower than the UO2Be group. The total
releases of iodine gases were one and two orders of magnitude
lower, for 133I and 131I, respectively.

These differences in total releases for the groups are clearly
reflected in the deposition maps available in Bartnicki et al. (2013).
Also, differences in particle sizes for individual components within
each group were quite significant and probably the most important

Fig. 5. Comparison of dry (top) and wet (bottom) deposition maps from SNAP runs with
accident at the final destination. Both wet and dry deposition is the sum of depositions fro

in terms of deposition levels in Norway. Deposition from UO2Be
components was higher than deposition from the Bitumen group
and slightly lower than the deposition from the Metal group
(Bartnicki et al., 2013). The main reason for lower deposition of the
Metal group, despite very similar levels of release, was the higher
density of particles in the metal group compared to the Bitumen
group. The difference in total release was so large that deposition
from the last group, 106Ru, was hardly visible on themaps and could
only be seen close to the source (Bartnicki et al., 2013).

There are some similarities for all groups of particles. Namely,
long range transport is most effective when the particle size is
below 1 mm. For the UO2Be group, deposition fields were very
similar for particles with sizes 0.1, 0.2 and 1.0 mm. Above 1 mm,
the transport range rapidly decreased and for particles with sizes
above 20 mm (50 and 100 mm) only local areas, close to the source,
were subject to deposition. To illustrate this fact, four maps for

the final source term specified in Table 4 and worst case meteorological scenario for
m all 30 components. Units: Bq m�2.

Fig. 6. Deposition maps from SNAP runs with individual UO2Be particles with the radius 0.1, 1.0, 10.0 and 20.0 mm. Total (dry þwet) deposition is shown after 96 h from the accident
start in Gremikha Bay. Units: Bq m�2.

Fig. 7. Maps of total (sum of depositions from all 30 components) from SNAP runs with the final source term specified in Table 4 and worst case meteorological scenario for accident
at the final destination after 12, 24, 48 and 96 h from the accident start. Units: Bq m�2.

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 413

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416414

individual UO2Be particles with different sizes are presented in
Fig 6.

Deposition fields for radioisotopes of Iodine and especially for 133I
were similar to the deposition fields of particles with a radius below
1 mm.

3.6. Dynamics of the transport

The radioactive cloud resulting from the potential accident
scenario where K-27 is located in Gremikha Bay has the potential to
be transported rapidly towards Norway. The evolution in time was
analysed by inspection of the total deposition maps for the worst
case meteorological scenario and a potential accident at this final
destination location for the submarine. The maps were calculated
for the period of 96 h with 3 h intervals and the same scale is used

Fig. 8. Comparison of total deposition map from the worst case K-27 scenario (top) with tota
maps. Deposition data for Norway from Chernobyl accident were provided by NRPA (Backe

for all of them. Here, we only present four maps in Fig. 7, as ex-
amples. For the complete set of these maps we refer to Bartnicki
et al. (2013).

Already after 8e9 h after the initial accident, the Norwegian
cities such as Vadsø, Vardø and Kirkenes would be contaminated
with radioactive fallout. In the next 1e2 h contamination would
extend to the towns of Mehamn and Hammerfest. After 18e20 h of
transport, the city of Tromsø would also be affected by deposition.
Subsequently, in the next 15e16 h, deposition from the radioactive
cloud would only expand over the sea. Approximately 35e36 h
from the accident start, Namsos and Steinkjer would be affected by
the deposition and slightly later, after the next 9 h, Trondheim
would also be affected. In the next stage, the radioactive cloud was
predicted to travel to Sweden reaching the Baltic Sea after a
transport time of 51 h. Because of the deposition scale used, Oslo

l deposition map from the Chernobyl accident (bottom). The same scale is used on both
et al., 1986).

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416 415

was not covered by the deposition, however with a source term
involving a higher release than the one considered here for a po-
tential K-27 accident, we would expect radionuclides to be
deposited in the Oslo area as well. Under such circumstances, the
estimated travel time would be 40e45 h after the start of the
accident.

3.7. Comparison with Chernobyl accident

The total deposition over Norway from the potential K-27 ac-
cident was compared with the deposition from the Chernobyl ac-
cident in the same domain, as shown in Fig. 8.

The deposition data after the Chernobyl accident was based on
soil measurements of 137Cs in municipalities in Norway (Backe
et al., 1986). The data have been gridded using regularized splines
with tension interpolation (Mitasova and Hofierka, 1993). Subse-
quently, the results have been smoothed to compensate for local
extremes, and to provide maps which might be more easily
compared with modelled depositions.

After the Chernobyl accident, central Norway and especially
some mountain regions were affected by relatively high levels of
137Cs deposition. The maximum, above 50 kBq m�2 137Cs, was
observed in the Valdres and Jotunheimen areas. The helicopter
measurements made in 2011 over Jotunheimen have revealed that
the deposition in 1986 was above 200 kBq m�2 in the most
contaminated areas (Baranwal et al., 2011; Skuterud et al., 2014).
The maximum deposition from the potential K-27 accident would
be at least two orders of magnitude lower (100e300 Bq m�2) than
the maximum deposition attributable to Chernobyl and largely
restricted to northern Norway. The deposition in southern Norway
associated with the potential release from K-27 will be two to three
orders of magnitude lower than the maximum levels associated
with the Chernobyl accident.

4. Conclusions

The main conclusions from this study with regards to a hypo-
thetical accident at submarine K-27 situated at Novaya Zemlya and
transported to a final destination in Gremikha, are:

� The number of cases with deposition above zero over Norwe-
gian territory decreases with the distance between the release
location and Norway. For releases at the initial location (Stepo-
vogo Fjord), during transport and at the final destination (Gre-
mikha Bay) of the submarine, the probabilities of deposition
events occurring over Norwegian territory are 17%, 25% and 37%,
respectively. This relationship was also reflected in the maps
showing the probability of arrival to Norway. The worst case
meteorological scenarios were selected for the dates: 26 August
1998, 7 September 1986 and 22 September 2004, for hypo-
thetical accident locations corresponding to the initial destina-
tion, during transport and at the final destination, respectively.
The worst meteorological case among all destinations is the one
at Gremikha Bay.

� Model simulations with a source term corresponding to the
worst case accident scenario showed that for all locations of the
potential accident, the northern part of Norway would be
affected. Central Norway could also be affected by contamina-
tion, in addition to northern Norway, if the potential accident
occurred in K-27 when located at Gremikha Bay. In all compu-
tations, the contribution of wet deposition to total deposition
was much higher than the contribution from dry deposition.

� The differences in total release for individual particle groups are
clearly visible in calculated depositions. Long range transport
wasmost effective when the particle radius was below 1 mm. For

particles with a radius of 50 mm and above only local areas, close
to the sources, were subject to radioactive particle inputs.

� The radioactive cloud resulting from the K-27 potential accident
when situated in Gremikha Baywas transported rapidly towards
Norway in the worst case scenario. Already after 8e9 h from the
start of the accident, a large part of northern Norway would be
contaminated. Approximately 35e36 h from the accident start, a
large part of central Norway would also be affected.

� Compared to the Chernobyl accident, the maximum deposition
level from K-27 accident is predicted to be at least 100 times
lower than the maximum deposition in Norway from the
Chernobyl accident. Also the area of Norway affected is different
in both cases. Primarily northern Norway would be affected
from the K-27 accident whereas mostly central Norway was
affected by fallout from the Chernobyl accident.

There are two general conclusions from this study: (1) Assuming
that the source term for the worst case K-27 accident scenario is
reasonable, there are no substantial radiological consequences for
Norway. Even the maximum predicted levels would be much lower
than in case of Chernobyl accident. (2) Calculated depositions are
very sensitive to the magnitude of the source term used. Therefore,
for estimation of the radiological risk to Norway, it is very impor-
tant to develop as accurate as possible estimations of the source
term in case of a potential accident involving the K-27 submarine.
For this reason, much effort has been expended on precisely this
task in preparation for the simulations presented in this paper.

Acknowledgements

We are grateful to the Norwegian Radiation Protection Authority
for partial financial support of this project and for collaboration
within the Centre for Environmental Radioactivity, CERAD, Centre
of Excellence CoE. This work was partly supported by the Research
Council of Norway through its Centres of Excellence funding
scheme, project number 223268/F50.

References

Backe, S.H., Bjerke, A.L., Rudjord, F., Ugletveit, F., 1986. Deposition of Cesium in
Norway after Chernobyl Accident (Report No. 5). National Institute of Radiation
Hygiene, Østerås, Norway (in Norwegian).

Baklanov, A., Sørensen, J.H., 2001. Parameterization of radionuclide deposition in
atmospheric long-range transport modeling. Phys. Chem. Earth (B) 26 (10),
787e799.

Baranwal, V.C., Ofstad, F., Rønning, J.S., Watson, R.J., 2011. Mapping of Caesium
Fallout from the Chernobyl Accident in the Jotunheimen Area (Report
2011.062). Geological Survey of Norway (NGU), Trondheim, Norway, p. 26.

Bartnicki, J., Saltbones, J., 1996. Severe nuclear accident program (SNAP) e a real
time dispersion model. In: Zannetti, P., Brebbia, C.A. (Eds.), Development and
Application of Computer Techniques to Environmental Studies VI. Computa-
tional Mechanics Publications, Southampton, Boston, pp. 17e26.

Bartnicki, J., Salbu, B., Saltbones, J., Foss, A., Lind, O.C., 2003. Long-range transport of
large particles in case of nuclear accident or explosion. In: Borrego, C.,
Incencik, S. (Eds.), Air Pollution Modelling and its Application XVI. Kluwer Ac-
ademic/Plenum Publishers, New York, Boston, pp. 77e86.

Bartnicki, J., Salbu, B., Saltbones, J., Foss, A., 2005. Analysis of Atmospheric Transport
and Deposition of Radioactive Material Released during a Potential Accident at
Kola Nuclear Power Plant (Research Report No. 10, ISSN 1503-8025). Norwegian
Meteorological Institute, Oslo, Norway.

Bartnicki, J., Haakenstad, H., Hov, Ø., 2011. Operational SNAP Model for Remote
Applications from NRPA (Research Report No. 12, ISSN 0332-9879). Norwegian
Meteorological Institute, Oslo, Norway.

Bartnicki, J., Heiko, K., Hosseini, A., Hov, Ø., Haakenstad, H., Ole Lind, O.C., Salbu, B.,
Szacinski Wendel, C.C., 2013. Atmospheric Transport of Radioactive Debris to
Norway in Case of a Hypothetical Accident Related to the Possible Recovery of
K-27 Submarine (Research Report No. 21, ISSN 0332-9879). Norwegian Mete-
orological Institute, Oslo, Norway.

Dee, D.P., Uppala, S.M., Simmons, A.J., Berrisford, P., Poli, P., Kobayashi, S., Andrae, U.,
Balmaseda, M.A., Balsamo, G., Bauer, P., Bechtold, P., Beljaars, A.C.M., van de
Berg, L., Bidlot, J., Bormann, N., Delsol, C., Dragani, R., Fuentes, M., Geer, A.J.,
Haimberger, L., Healy, S.B., Hersbach, H., Holm, E.V., Isaksen, L., Kållberg, P.,
Kohler, M., Matricardi, M., McNally, A.P., Monge-Sanz, B.M., Morcrette, J.-J.,

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref1

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref2

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref3

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref4

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref5

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref6

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref7

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref8

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref9

J. Bartnicki et al. / Journal of Environmental Radioactivity 151 (2016) 404e416416

Park, B.-K., Peubey, C., de Rosnay, P., Tavolato, C., Thepaut, J.-N., Vitart, F., 2011.
The ERA-Interim reanalysis: configuration and performance of the data
assimilation system. Quart. J. R. Meteorol. Soc. 137, 553e597.

Hoe, S., MüH., Gering, F., Thykier-Nielsen, S., Sørensen, J.H., 2002. ARGOS 2001 a
decision support system for nuclear Emergencies. In: Proceedings of the Ra-
diation Protection and Shielding Division Topical Meeting, April 14e17, 2002,
Santa Fe, New Mexico, USA.

IAEA, 1997. Predicted Radionuclide Release from Marine Reactors Dumped in the
Kara Sea. Report of the source term working group of the International Arctic
Seas Assessment Project (IASAP). International Atomic Energy Agency, Vienna
(TECDOC-938).

Lavkovsky, S.A., 1999. Overview of the project 101B-96 ISTC (Kurgan). In: Interna-
tional Seminar on ISTC Projects Radiation Legacy in the CIS, Brussels, March
1999.

Lide, D.R., 2005. CRC Handbook of Chemistry and Physics: a Ready-reference Book
of Chemical and Physical Data. Taylor & Francis, Boca Raton, Fla.

Maryon, R.H., Saltbones, J., Ryall, D.B., Bartnicki, J., Jakobsen, H.A., Berge, E., 1996. An
Inter-comparison of Three Long Range Dispersion Models Developed for the UK
Meteorological Office, DNMI and EMEP. U. K. Met Office Turbulence and
Diffusion Note 234. UK Meteorological Office, Bracknell, United Kingdom.

Mitasova, H., Hofierka, J., 1993. Interpolation by regularized splines with tension.
Math. Geol. 25 (6).

NRPA, 2015. Inventory and source term evaluation of the dumped nuclear sub-
marine K-27. Strålevernsrapport (in preparation).

Reistad, M., Breivik, Ø., Haakenstad, H., Aarnes, O.J., Furevik, B.R., Bidlo, J.-R., 2011.
A high resolution hindcast of wind and waves for The North Sea, The Norwegian
Sea and The Barents Sea. J. Geophys. Res. 116, C05019. http://dx.doi.org/10.1029/
2010JC006402.

Salbu, B., Lind, O.C., 2011. Radioactive particles released into the environment from
nuclear events. In: Actinide Nanoparticle Research. Springer, pp. 335e359.

Salbu, B., Skipperud, L., 2009. Speciation of radionuclides in the environment.
J. Environ. Radioact. 100, 281e282.

Salbu, B., Krekling, T., Lind, O.C., Oughton, D.H., Drakopoulos, M., Simionovici, A.,
Snigireva, I., Snigirev, A., Weitkamp, T., Adams, F., Janssens, K., Kashparov, V.A.,
2001. High energy X-ray microscopy for characterisation of fuel particles. Nucl.
Instrum. Methods, Part A 467 (21), 1249e1252.

Saltbones, J., 1995. Real-time dispersion model calculations as part of NORMEM-
WP19. Saf. Sci. 20, 51e59.

Saltbones, J., Foss, A., Bartnicki, J., 1996. A real time dispersion model for severe
nuclear accidents tested in the European tracer experiment. Syst. Anal. Model.
Simul. 25, 263e279.

Saltbones, J., Foss, A., Bartnicki, J., 1998. Norwegian meteorological Institute’s real-
time dispersion model SNAP (Severe nuclear accident program). Runs for
ETEX and ATMES II experiments with different meteorological input. Atmos.
Environ. 32 (24), 4277e4283.

Saltbones, J., Bartnicki, J., Foss, A., 2003. Handling of Fallout Processes from Nuclear
Explosions in Severe Nuclear Accident Program e SNAP (Research Report No.
157). Norwegian Meteorological Institute, Oslo, Norway.

Skuterud, L., Thørring, H., Ytre-Eide, M.A., 2014. Conference Paper: Use of total 137Cs
deposition to predict contamination in feed vegetation and reindeer 25 years
after Chernobyl. In: ICRER 2014 e Third International Conference on Radio-
ecology and Environmental Radioactivity, Barcelona. http://dx.doi.org/10.13140/
2.1.2980.9928.

Und�en, P., Rontu, L., J€arvinen, H., Lynch, P., Calvo, J., Cats, G., Cuaxart, J., Eerola, K.,
Fortelius, C., Garcia-Moya, J.A., Jones, C., Lenderlink, G., McDonald, A., Mc-
Grath, R., Navascues, B., Nielsen, N.W., Ødegaard, V., Rodriguez, E.,
Rummukainen, M., R€o€om, R., Sattler, K., Sass, B.H., Savij€arvi, H., Schreur, B.W.,
Sigg, R., The, H., Tijm, A., 2002. HIRLAM-5 Scientific Documentation (HIRLAM-5
project). Swedish Meteorological and Hydrological Institute, Norrk€oping,
Sweden.

Uppala, S.M., Kållberg, P.W., Simmons, A.J., Andrae, U., da Costa Bechtold, V.,
Fiorino, M., Gibson, J.K., Haseler, J., Hernandez, A., Kelly, G.A., Li, X., Onogi, K.,
Saarinen, S., Sokka, N., Allan, R.P., Andersson, E., Arpe, K., Balmaseda, M.A.,
Beljaars, A.C.M., van de Berg, L., Bidlot, J., Bormann, N., Caires, S., Chevallier, F.,
Dethof, A., Dragosavac, M., Fisher, M., Fuentes, M., Hagemann, S., H�olm, E.,
Hoskins, B.J., Isaksen, L., Janssen, P.A.E.M., Jenne, R., McNally, A.P., Mahfouf, J.-F.,
Morcrette, J.-J., Rayner, N.A., Saunders, R.W., Simon, P., Sterl, A., Trenberth, K.E.,
Untch, A., Vasiljevic, D., Viterbo, P., Woollen, J., 2005. The ERA-40 re-analysis.
Quart. J. R. Meteorol. Soc. 131, 2961e3012.

Wendel, C., Fifield, L.K., Oughton, D.H., Lind, O.C., Skipperud, L., Bartnicki, J., Tims, S.,
Høibråten, S., Salbu, B., 2013. Long-range tropospheric transport of uranium and
plutonium weapons fallout from Semipalatinsk nuclear test site to Norway.
Environ. Int. 59, 92e102.

Wright, S.M., Strand, P., Sickel, M.A.K., Howard, B.J., Howard, D.C., Cooke, A.I., 1997.
Spatial variation in the vulnerability of Norwegian Arctic counties to radio-
caesium deposition. Sci. Total Environ. 202, 173e184.

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref9

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref10

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref11

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref12

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref13

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref14

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref15

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref16

http://dx.doi.org/10.1029/2010JC006402

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref18

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref19

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref20

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref21

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref22

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref23

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref24

http://dx.doi.org/10.13140/2.1.2980.9928

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref26

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref27

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref28

http://refhub.elsevier.com/S0265-931X(15)00061-2/sref29

Atmospheric transport of radioactive debris to Norway in case of a hypothetical accident related to the recovery of the Rus …

1. Introduction
2. Material and methods
2.1. SNAP model
2.2. Meteorological database
2.3. Selection procedure
2.4. Worst case source term for K-27 accident
3. Results and discussion
3.1. Selection of the worst case meteorological scenarios
3.2. Probability maps
3.3. Worst case scenarios with the final source term
3.4. Dry versus wet deposition
3.5. Depositions from individual components
3.6. Dynamics of the transport
3.7. Comparison with Chernobyl accident
4. Conclusions
Acknowledgements
References

Turn in your highest-quality paper
Get a qualified writer to help you with

“ Reading and Answering 3 ”

Get high-quality paper

NEW! AI matching with writer

Hire a Writer

Client Reviews

4.9

Sitejabber

4.6

Trustpilot

4.8

Our Guarantees

100% Confidentiality

Information about customers is confidential and never disclosed to third parties.

Original Writing

We complete all papers from scratch. You can get a plagiarism report.

Timely Delivery

No missed deadlines – 97% of assignments are completed in time.

Money Back

If you're confident that a writer didn't follow your order details, ask for a refund.

New to Your Trusted Assignment Help Service? Sign up & Save

Calculate the price of your order

Type of paper needed:

Pages:

You will get a personal manager and a discount.

Academic level:

We'll send you the first draft for approval by at

Total price:

$0.00

Power up Your Academic Success with the
Team of Professionals. We’ve Got Your Back.

Power up Your Study Success with Experts We’ve Got Your Back.

Order Now Order Now