D.Belyashov, A.Tichshenko

Institute of Natural Sciences, Almaty, Kazakhstan

 

GEOETHICS PROBLEMS CAUSED BY UNDERGROUND NUCLEAR EXPLOSIONS

 

Abstract

 

Near two and a half milleniums ago Hippocrates determined the main principle of medicine as non nocere (do not damage).  To our opinion this principle could be applied to geoethics as well.  From this point of view in the report some problems of how nuclear explosions affected the conditions of geological environment and ecological situation will be considered. 

 

 

During several decades, a huge amount of underground nuclear explosions (UNE) was conducted in different parts of the world. More of them were the tests of nuclear weapons. Besides that, a series of the so-called “peaceful” nuclear explosions took place to solve a number of national economic problems.

 

It is necessary to mark that in many cases planned tasks were successfully solved. At the same time, after years in many regions some negative consequences of UNE have appeared. The results of how UNE affects geological environment were rather widely discussed in press. Some negative consequences of UNE resulted in appearance of radionuclides and other contaminating materials in the ground water and productive series and their crop out due to migration of radionuclides in weak zones and forcing of radioactive contaminated solutions from the UNE cavities after their collapsing.

 

Examples of some negative consequences of Underground Nuclear Explosions are listed below.

 

Galit Facility:                 gases and radioactive ground dismissing from the cavities, appearance of “white” fogs, ulcerating of the horse’s extremities, whitening of plants and insects, and flooding of the cavities.

 

Vega Facility:                decrease in volume of the test cavities and their flooding, output of radioactive brines on the surface, contamination of underground water. At a distance of two kilometers from one of the test holes tritium was found in the water-bearing horizon of mesokainozoic cover.

 

Grachevskoye            tritium appearance in the ground water at a distance up to 3

Oil Deposit:                 kilometers from test site

 

Osinskoye                   radionuclides appearance in petroleum producing facilities,

Deposit:                      dismissing of radioactive water.

 

Nevada Test Site: plutonium migration in the bed water at a distance of 1.5 km from the epicenter of the underground nuclear explosion.

 

Semipalatinsk               disturbing the centers of local seismic activity located close

Test Site:                      to nuclear cavities; unexpected explosion in the Glubokaya hole; short and long term variation of chemical contents of underground waters caused by UNE.

 

There are many other examples of how UNE negatively affects the subsurface.  Thusly, the main principle of geoethics “non nocere” (do not damage) was violated.

 

At the same time it has to be indicated that having highly enough level of knowledge about the influence of nuclear explosions on the earth crust condition it would be possible to exclude negative consequences in many cases.

 

The authors believe in the future development of atomic energy industry and in high effectiveness of underground nuclear explosions conducting for solving different economic problems.

 

            To conduct underground nuclear explosions for economic purposes in the future it is necessary to set up a geological and geophysical monitoring of the sites where UNE were conducted. It will allow to study the processes caused by UNE and to develop some methods of the process forecasting providing with recommendations on security.

 

The main approaches to organize the monitoring of subsurface in the places of UNE conducting will be given in the next chapter.

                         

 

Objectives of the Subsurface Monitoring

 

Monitoring of subsurface aims to observe the status of the subsurface and collect the data concerning:

-         conditions of rocks, including their contamination by chemical and radioactive components;

-         status of underground water;

-         dangerous geological activity (both exogenous and endogenous);

-         status of the storage of harmful and radioactive wastes;

-         geophysical, seismic and other fields.

 

Other objectives of the monitoring could be an assessment of the subsurface status, forecast of possible changes in subsurface, development of recommendations about administrative measures to be undertaken by corresponding state departments.

 

 

Assessment of Rock Conditions, Including Contamination by Harmful Chemical and Radioactive Components

 

Assessment of rock conditions includes theoretical and experimental research goes toward obtaining the data about the character of distribution of physical, mechanical, geological and sorption features of rocks forming the blocks where nuclear cavities are located.   Besides that, the assessment can involve geological and geophysical research to provide charting of zones of possible ways of radionuclides migration to the day surface (lithochemical research).   Express georadioecological charting can provide an assessment of contamination by the main technological radionuclides (Cs137, Sr90, Pu239-241), gamma-spectrum research of bore holes, remote research are another components of the rock assessment.

 

 

Assessment of Underground Water

 

The assessment of underground water starts from feasibility study and equipping of hydrogeolological bore holes for observation.   To assess the quality of the water it is necessary to analyze a content of radioactive and other toxic components in natural water.  Another possible test is bio-testing of natural water.

 

 

Research of Dangerous Geological Processes

 

·        Epeirogenous processes

 

According to B.Golubev, the author of a number of publications concerning nuclear test sites, one of the reasons why cavities of Vega facilities are collapsing is low-temperature deformation of massive rock in the area of unstable tenses.  The tenses come from the changes of the Caspian Sea level that caused by earth oscillations.  According to preliminary estimates in 10-30 years the territory with Lira facilities will have the same phase of epeirogenous oscillations as Vega facilities had during its cavities collapsing.

 

Analysis of the dynamics of sea level using height marks on the large territory will allow obtaining of precise assessment.  For this purpose can serve the results of measurements made on geo-dynamical areas by high-precise satellite systems.  Another way to estimate dynamics of the earth crust is to analyze a rhythmic of bottom deposits  of lakes.

 

 

·        Influence of solar and moon flows on the status of nuclear cavities.

 

Possible influence of the solar and moon flows on the status of nuclear cavities and changes of gamma activity in this connection was marked by L.Pevzner.  This hypothesis was proved by receiving a close correlation between the solar and moon cycles and time changes of intensity of gamma field along the section of some test-holes and observing holes at Lira facilities.

 

 

·        Assessment of tectonic tension of the earth block contained nuclear cavity.

 

Tectonic tension involves both natural and industrial (oil extraction etc.) activity.  To estimate the tectonic tension method of passive seismic surveying could be used.

 

·        Assessment of after explosion processes of epigenetic mineral formation (hydration of anhydride etc.)

 

·        Assessment of after explosion radio-chemical processes .

 

According to the data obtained by Murzadilov, each cavity of the Lira facility isolated 300 kilograms of chlorine.

 

 

 

Assessment of subsurface conditions and status of storage facilities

 

The complex assessment of subsurface conditions and status of storage facilities includes assessment of morphology of nuclear cavities carried out by acoustic geomethods and an estimation of the status of hydroisolation of the cavities and radionuclide contamination.  Besides, it is appropriate to conduct a 3D charting of physical and mechanical transgression of rock blocks.  Studying of structural and tectonic features of geological environment of the cavity can help to find possible ways of migration of contaminated materials.  In addition, it is necessary to study hydrodynamics of radio-contamination of open-end water-bearing zones of broken tectonics and centers of their relaxation into water bearing horizons of the over dome structural level.  Moreover, it is necessary to assess technological condition and protection of pipes of the cavities.

 

 

Forecasting changes of subsurface

 

Forecasting changes of the subsurface is a final task of the proposed monitoring.  The task can be solved by developing of a special complex 3D dynamical model that will determine both structural and tectonic fluid-dynamical regimes of the block of the earth crust, which contains nuclear cavities. The model is based on the data obtained during observation of subsurface conditions that involve information about geological structure, physical and chemical features of water and rocks, and information about character of current natural and industrial processes.