Underground Nuclear Explosion Site Research Articles

Radiation situation at the “Pirit” peaceful underground nuclear explosion site

The aim of this study was to evaluate radiation situation at the “ Pirit ” peaceful underground nuclear explosion site . The peaceful underground nuclear explosion “ Pirit ” with the capacity of 37.6 kt оf TNT equivalent was carried out on May 25, 1981 on the territory of the Kumzhinskoye gas condensate field at a depth of 1.5 km . The field is located near the northern coast of the European part of Russia in the delta of the Pechora River ( Nenets Autonomous District ). The peaceful underground nuclear explosion “ Pirit ” was carried out with the aim to stop the uncontrolled gas gushing . Radiation situation is assessed according to the main indicators : dose rate values and content of technogenic radionuclides in soil and water . The radiation survey included d etermining g eographic c oordinates o f s pecific l andscape e lements , m easurement a nd s ampling p oints u sing s atellite n avigators , m easurement o f a mbient d ose e quivalent r ate , i dentification o f g amma-emitting r adionuclides i n s itu b y f ield g amma s pectrometry , s ampling o f w ater , p hoto a nd v ideo s hooting . On t he s ite o f t he u nderground n uclear e xplosion “ P irit ” t he v alues o f t he a mbient d ose e quivalent r ate w ere i n t he r ange o f 0.050–0.089 μ Sv / h, w hich c orresponds t o t he l evels o f t he n atural r adiation b ackground . No s ites o f l ocal r adioactive c ontamination o f s oil b y 137Cs w ere d etected . The t ritium c ontent ( l ess t han 5 B q / k g ) i n w ater b odies d oes n ot e xceed t he l evels o f f luctuations o f t his i ndicator i n o ther r egions o f t he European t erritory o f Russia. The e stimated v alue o f t he e ffective d ose d ue t o i ngestion o f t ritium i n d rinking w ater i n l ocal s ettlements w as 0.044 μ Sv / y ear . The r adiation s ituation o n t he t erritory o f t he p eaceful n uclear e xplosion “ P irit ” m eets t he r equirements o f t he Russian S anitary R egulations a nd Standards 2.6.1.2819-10 “ E nsuring t he r adiation s afety o f t he p opulation l iving i n t he r egions o f n uclear e xplosions f or p eaceful p urposes (1965–1988)” a nd c urrently d oes n ot p ose a t hreat t o p ublic h ealth . D ue t o t he p otential d anger o f t echnogenic r adionuclides c oming f rom t he e picenter o f t he e xplosion t o t he s urface f or l ong-term r adiation s afety , i t i s n ecessary t o o rganize r adiation m onitoring o f t he t erritory a djacent t o t he e xplosion s ite , d etermine t he b oundaries o f t he p rotected z one a nd s et a ppropriate i nformation s igns w arning o f r adiation d anger .

Evaluating the Radiation Status of the Environment on the Underground Nuclear Explosion Site Code-Named Tavda

This paper analyzes the radiation status of environmental components on the underground nuclear explosion site codenamed Tavda, which is located in the Nizhnetavdinsky District of Tyumen Oblast. This underground nuclear explosion occurred in 1967 and was part of the Program #7 Nuclear Explosions for the National Economy; it is currently one of the sources of radiation pollution in its environment. The authors hereof present the analysis of technogenic radionuclide contamination of soils in the explosion epicenter as well as within 500 meters thereof, which analysis takes into account the horizontal and vertical migration of radionuclides, and the contamination of grassy vegetation with strontium-90 and caesium-137 (measurements were taken at 100 m intervals).We have found out that the radiation burden is essentially a function of strontium-90 content in the soil. Maximum density of strontium-90 and caesium-137 contamination is observed in deeper soil layers. Technogenic radionuclide contamination is present in naturally growing grass on the Tavda site due to a high concentration of strontium-90 with a mean specific radionuclide activity of 288.33 Bq/kg, while the maximum permissible concentration of this element in natural hay is 180 Bq/kg. The concentration of caesium-137 in collected samples was not found to be in excess of the permissible concentrations.

Measurements of Argon-39 at the U20az underground nuclear explosion site

Pacific Northwest National Laboratory reports on the detection of 39Ar at the location of an underground nuclear explosion on the Nevada Nuclear Security Site. The presence of 39Ar was not anticipated at the outset of the experimental campaign but results from this work demonstrated that it is present, along with 37Ar and 85Kr in the subsurface at the site of an underground nuclear explosion. Our analysis showed that by using state-of-the-art technology optimized for radioargon measurements, it was difficult to distinguish 39Ar from the fission product 85Kr. Proportional counters are currently used for high-sensitivity measurement of 37Ar and 39Ar. Physical and chemical separation processes are used to separate argon from air or soil gas, yielding pure argon with contaminant gases reduced to the parts-per-million level or below. However, even with purification at these levels, the beta decay signature of 85Kr can be mistaken for that of 39Ar, and the presence of either isotope increases the measurement background level for the measurement of 37Ar. Measured values for the 39Ar measured at the site ranged from 36,000 milli- Becquerel/standard-cubic-meter-of-air (mBq/SCM) for shallow bore holes to 997,000 mBq/SCM from the rubble chimney from the underground nuclear explosion.

Membrane luminescence determination of technogenic actinides and their speciation in environmental objects

Researchers of the Vernadsky Institute of Geochemistry and Analytical Chemistry of the Russian Academy of Sciences created a luminescence photometer of a new generation for the determination of trace amounts of uranium and transuranium elements (TUE). The limits of detection for actinides vary from 0.3 pg for uranium and neptunium to 2.0 pg for plutonium. For 237Np, the relative limit of detection is 0.008 Bq/L. The photometer was tested in the radioecological monitoring of a number of polluted zones in Russia. The dynamics of actinide migration in all of the studied zones enhanced in the series 239Pu 241Am > 239Pu irrespectively of the soil. In the group of humic acids, concentrations of radionuclides increased in the series 237Np < 239Pu < 241Am. The sorption coefficients of radionuclides by bottom sediments of the Markha River (Kraton-3 underground nuclear explosion site) and Lake Kyzyltash (East Urals Radioactive Trace) were calculated. Bioaccumulation factors of radionuclides by different plants in the impact area of the Kraton underground nuclear explosion were determined depending on the plant type.

Radiological investigations at the “Taiga” nuclear explosion site: Site description and in situ measurements

In the summer of 2009, we performed a field survey of the “Taiga” peaceful underground nuclear explosion site, the Perm region, Russia (61.30° N, 56.60° E). The explosion was carried out by the USSR in 1971. This paper provides an extended summary of the available published data on the “Taiga” experiment. A detailed description of the site is illustrated by original aerial and ground-level photos. A large artificial lake (700 m long and 350 m wide) currently occupies the central area of the experimental site. The ground lip surrounding the lake is covered by a newly grown mixed forest. In situ measurements, performed in August 2009, revealed elevated levels of the γ-ray dose rate in air on the banks of the lake “Taiga”. Two hot spots were detected on the eastern bank of the lake. The excess of the γ-ray radiation is attributable to the man-made radionuclides 60Co and 137Cs. The current external γ-ray dose rate to a human from the contaminations associated with the “Taiga” experiment was between 9 and 70 μSv per week. Periodic monitoring the site is recommended.

Radioecological studies at the Kraton-3 underground nuclear explosion site in 1978–2007: a review

Within this paper, radioecological data concerning the “peaceful” underground nuclear explosion Kraton-3, conducted at a remote Arctic location (65.9°N, 112.3°E) within the former USSR in 1978, are reviewed. The data and estimates published in the available literature sources before September 2008 could be grouped as following: (a) characterisation of the current radioactive contamination (γ-, β- and α-emitters) of environmental compartments in terms of radionuclides composition, activity concentration, area contamination density; (b) determination of current gamma dose rates in air, including mapping using GPS; (c) evaluation of cumulative gamma doses in air (with calculations and thermoluminiscence measurements in ceramic objects); (d) description of the visually distinguishable changes in the terrestrial ecosystem; (e) description and quantitative evaluation of morphological abnormalities in the organs of adult plants as well as in seeds and seedlings of some herbs and shrubs, and in small mammals; (f) application of countermeasures. Knowledge gaps and possible further studies are indicated.

Radiostrontium hot spot in the Russian Arctic: ground surface contamination by 90Sr at the “Kraton-3” underground nuclear explosion site

Strontium-90 activity concentrations in surface soils and areal deposition densities have been studied at a site contaminated by an accidental release to atmosphere from the underground nuclear explosion “Kraton-3” conducted near the Polar Circle (65.9°N, 112.3°E) within the territory of the former USSR in 1978. In 2001–2002, the ground surface contamination at 14 plots studied ranged from 20 to 15 000 kBq m −2, which significantly exceeds the value of 0.44 kBq m −2 deduced for three background plots. The zone with substantial radiostrontium contamination extends, at least, 2.5 km in a north-easterly direction from the borehole. The average 137Cs/ 90Sr ratio in the ground contamination originated from the “Kraton-3” fallout was estimated to be 0.55, which is significantly different from the ratio of 2.05 evaluated for background plots contaminated mostly from global fallout. Although vertical migration of 90Sr in all undisturbed soil profiles studied is more rapid than that for 137Cs, the depth of percolation of both radionuclides into the ground is mostly limited to the top 10–20 cm, which may be explained, primarily, by permafrost conditions. The horizontal migration rate of radiostrontium in the aqueous phase exceeds the radiocaesium migration rate by many times. This phenomenon seems to be a reason for the significant enrichment of the soil surface layers by radiostrontium at some sites, with variations occurring in accordance with small-scale irregularities of landscape.

137Cs and 90Sr in live and dead reindeer lichens (genera Cladonia) from the “Kraton-3” underground nuclear explosion site

The contents of 137Cs and 90Sr have been determined in 29 samples of live and dead reindeer lichens (genera Cladonia) collected at the “Kraton-3” underground nuclear explosion site (65.9°N 112.3°E, event year – 1978) in Yakutia, Russia in 2002. The area contamination was within the range of 0.36–700 and 0.13–770 kBq m −2 for 137Cs and 90Sr, respectively. The dead organisms were on average much more contaminated than the live ones. Vertical fractionation of the live lichen carpet demonstrated maximal activity concentrations of both radionuclides in the lower older section of the plants, while for the dead lichens the maximal activity concentrations of 137Cs were detected in the upper part. The vertical distribution of 90Sr was more or less homogeneous in the cushions of dead lichens. Elevated levels of 137Cs and 90Sr activity concentrations were also detected in the re-establishing young lichens growing over the residua of some dead lichens.

Surface ground contamination and soil vertical distribution of 137Cs around two underground nuclear explosion sites in the Asian Arctic, Russia

Vertical distributions of 137Cs have been determined in vegetation-soil cores obtained from 30 different locations around two underground nuclear explosion sites – “Crystal” (event year – 1974) and “Kraton-3” (event year – 1978) in the Republic of Sakha (Yakutia), Russia. In 2001–2002, background levels of 137Cs surface contamination densities on control forest plots varied from 0.73 to 0.97 kBq m −2 with an average of 0.84 ± 0.10 kBq m −2 and a median of 0.82 kBq m −2. 137Cs ground contamination densities at the “Crystal” site ranged from 1.3 to 64 kBq m −2; the activity gradually decreased with distance from the borehole. For “Kraton-3”, residual surface contamination density of radiocaesium varied drastically from 1.7 to 6900 kBq m −2; maximal 137Cs depositions were found at a “decontaminated” plot. At all forest plots, radiocaesium activity decreased throughout the whole vertical soil profile. Vertical distributions of 137Cs in soil for the majority of the plots sampled ( n = 18) can be described using a simple exponential function. Despite the fact that more than 20 years have passed since the main fallout events, more than 80% of the total deposited activity was found in the first 5 cm of the vegetation-soil cores from most of the forested landscapes. The low annual temperatures, clay-rich soil type with neutral pH, and presence of thick lichen-moss carpet are the factors which may hinder 137Cs transport down the soil profile.

Genotoxicity and cytotoxicity assay of water sampled from the underground nuclear explosion site in the north of the Perm region (Russia)

The results of our study revealed a local biologically relevant surface water contamination in the radionuclide anomaly in the north of Russia (Perm region) by means of Allium schoenoprasum L. anaphase–telophase chromosome aberration assay. This radionuclide anomaly was formed in 1971 as a result of an underground nuclear explosion with soil excavation. Specific activities of main dose-forming radionuclides in all examined reservoirs are below intervention levels officially adopted in Russia for drinking water. We found that 90Sr significantly contributes to induction of cytogenetic disturbances. Our previous data and the data described here suggest that metal and radionuclide combined exposure (with the dose below permissible exposure limits for human) may cause substantial biological effects. These effects are in part due to synergic response. The findings described here indicated that development of a new concept of radiation protection for humans and biota should be based on the clear understanding of biological effects of low doses of radiation in chronic exposure to multi-pollutant mixtures.

Characterization of pre-β- and α-migrating HDL subfractions in Russian men with high and low HDL cholesterol level

Vertical distributions of 137Cs have been determined in vegetation-soil cores obtained from 30 different locations around two underground nuclear explosion sites – “Crystal” (event year – 1974) and “Kraton-3” (event year – 1978) in the Republic of Sakha (Yakutia), Russia. In 2001–2002, background levels of 137Cs surface contamination densities on control forest plots varied from 0.73 to 0.97 kBq m−2 with an average of 0.84 ± 0.10 kBq m−2 and a median of 0.82 kBq m−2. 137Cs ground contamination densities at the “Crystal” site ranged from 1.3 to 64 kBq m−2; the activity gradually decreased with distance from the borehole. For “Kraton-3”, residual surface contamination density of radiocaesium varied drastically from 1.7 to 6900 kBq m−2; maximal 137Cs depositions were found at a “decontaminated” plot. At all forest plots, radiocaesium activity decreased throughout the whole vertical soil profile. Vertical distributions of 137Cs in soil for the majority of the plots sampled (n = 18) can be described using a simple exponential function. Despite the fact that more than 20 years have passed since the main fallout events, more than 80% of the total deposited activity was found in the first 5 cm of the vegetation-soil cores from most of the forested landscapes. The low annual temperatures, clay-rich soil type with neutral pH, and presence of thick lichen-moss carpet are the factors which may hinder 137Cs transport down the soil profile.

Residual radioactive contamination at the peaceful underground nuclear explosion sites “Craton-3” and “Crystal” in the Republic of Sakha (Yakutia)

In this paper, results are reported on the concentrations and activity ratios of 137Cs, 239+240Pu and 238Pu in soils, lichen and bottom sediments collected at the peaceful underground nuclear explosion sites “Craton-3” and “Crystal” (Republic of Sakha (Yakutia), North-East Siberia). At the “Craton-3” site, 239+240Pu concentrations in the range 6.2 mBq/g to 5.9 Bq/g in surface soils (0–5 cm) and 239+240Pu concentrations up to 7.4 Bq/g in lichen were observed. The 137Cs concentration in measured soils range from 0.52 to 216 Bq/g for the near-plume and from 1.65 to 21.5 Bq/g for the far-plume. In lichen, 137Cs concentration varied from a global background level up to 251 Bq/g. Radioactive contamination at “Crystal” demonstrates an extremely irregular distribution of 239,240Pu and 137Cs in environmental samples taken at locations within 150 m radius of the site. Further work on compiling detailed maps of radioactive contamination of the territory around “Craton-3” and “Crystal” is discussed.

Radiological states around the Kraton-4 underground nuclear explosion site in Sakha.

A radiological survey around the site of Kraton-4, an underground nuclear explosion (Yield of 20 kt, depth of 560 m, 1978) in Sakha was carried out in March 1998. Gamma survey and in-situ spectroscopy on the ground exhibited quite normal levels: a dose rate of 0.022 microSv/h and Cs-137 surface contamination of less than 1.1 kBq/m2 around the hypocenter. The results suggested no remarkable leakage of radioactivity from the epicenter to the ground surface at least not for non-rare gas elements as of 1998.

Techniques and Deflection Tools in High-Angle Drilling: Past, Present and Future

Abstract Directional drilling is used extensively in the oil industry, and also has many uses in other fields. Early directional drilling is discussed in detail to familiarize the reader with its terminology and to help him more fully understand the need for improvements. In the past 10 years, directional drilling companies have developed many new, tools and techniques. Advantages and disadvantages of these improvements are pointed out in this article. Introduction Directional drilling, which was started in the early 1930's, has found a respected place in the oilfields of the world. In recent years it has become a highly scientific and technical profession. In the mid 1950's, engineers took directional drilling in hand and the established methods that were based entirely on experience began to give way to modern techniques. These techniques were designed to improve the mechanics of directional drilling and to reduce high costs of directional drilling jobs. This article presents the many improvements that have been made in directional drilling equipment and techniques in the past 10 years. The article represents the views of the author as obtained from experience as a directional driller, and from interviews with directional drilling representatives both in management and on the field engineer level. Uses of Directional Drilling The proper approach for illustrating these many improvements must begin with an understanding of directional drilling and its many uses. As applied to the oil industry, the deflecting of wellbores comes under three general headings. Sidetracking, in its most popular form, involves going around a fish left in the wellbore. Another example: when a producing reservoir is missed, a plugback and the accompanying oriented sidetrack can give a much more favorable bottom-hole location structurally. Sidetracking has been used often in secondary recovery work in both cased and uncased holes to move the bottom-hole location to an area of less depletion. A second general heading involves straightening or straightening up of a wellbore. This operation is mainly concerned with moving the bottom-hole location back to the proximity of the surface location. Typical applications would be drilling contract commitments, lease line obligations and bottom-hole well spacing requirements. A third general heading, and by far the most important, is planned directional drilling which has numerous applications, the largest being in offshore drilling operations. Platform-type directional drilling programs involving multiple wellbores have many cost-saving features, in both drilling and production phases. In multiple-well platforms of four to six wells, the initial costs would be equivalent to those of five or six individual vertical wells. However. with platforms of 12, 18 and 24 wells, economic operation is realized. Expensive rig moves are eliminated. The close proximity of multiple wellheads greatly simplifies gathering systems and production techniques. Under this same general heading fall relief wells that are drilled to kill uncontrolled blowouts. This application has no parallel in many instances. Another application involves inaccessible well sites. Typical examples are wells drilled under lakes and rivers, under populated metropolitan areas and difficult terrain such as mountainsides. Another use of directional drilling principles is the drilling of drain holes where many "roots" extend from a single wellbore in thick producing zones. These drain holes produce some of the most rapid drift angle buildups that are known, often 2 degrees/ft or angles completely horizontal. Other applications of directional drilling that are of interest would be drilling wellbores into shallow sulfur deposits and using super-heated steam to melt the sulfur for production. Completely opposite production techniques are planned for a potash field in Canada. Twenty to 25 wells are being directionally drilled to circulate a freezing medium and solidify underground water formations for a mining operation. Directional drilling has been used in recent years to tap underground nuclear explosion sites to obtain samples for radioactive analysis. Directional wellbores have been guided from mountain sites to intersect with tunneling operations for air purification purposes. JPT P. 469ˆ