Environmental Engineering Reference
In-Depth Information
2.29 Dispersion of Radioactive Debris from Nuclear
Explosions in Novaya Zemlya in 1958: Results of the
Model Simulations
Jerzy Bartnicki, Jørgen Saltbones, Hilde Haakenstad, and Bjørn Røsting
Norwegian Meteorological Institute, P.O. Box 43 Blindern, NO-0313 Oslo, Norway
Abstract
In October 1958 a series of large nuclear explosions has been performed
in the region of Novaya Zemlya in the former Soviet Union emitting a significant
amount of radioactivity into the stratosphere. The Severe Nuclear Accident
Program (SNAP) model has been used to simulate dispersion from each of three
selected explosions and stratospheric intrusion for the episode of high measured
activity in Bergen on 20 October 1958. Model simulations have shown that there
was no direct transport of radioactivity from Novaya Zemlya to Bergen and
strongly indicated that the stratospheric intrusion was the main mechanism
responsible for measured high level of radioactivity.
1. Introduction
In October 1958 a series of large nuclear explosions was performed in the region
of Novaya Zemlya in the former Soviet Union. All together 17 bombs were
detonated in October 1958, but of special interest are three large atmospheric
explosions which occurred on 12th, 15th and 18th October with the yield of 1.45,
1.5 and 2.9 Mt, respectively. These explosions emitted large amounts of radio-
activity directly into the stratosphere.
Several days after the detonations, significantly elevated levels of radioactivity
were measured at four stations of the Norwegian measurement network: Tromsø,
Vaernes, Vadsø and Bergen. The highest level was measured on 20 October in
Bergen, with a total beta activity in the air reaching 600 mBq m
−3
(Bergan et al.,
2005).
The time of the detonations in Novaya Zemlya was carefully planned in this
way that atmospheric transport of radioactive debris was mostly directed into the
Soviet Union. However, the measurements indicated at first that some direct
tropospheric transport from Novaya Zemlya to Norway could be responsible for
high levels of measured radioactivity.
On the other hand, trajectory analysis based on the meteorological data for the
time of explosions indicated that such a transport did not take place (Bartnicki
et al., 2004a) and stratospheric intrusion is the most likely mechanism responsible
