Radiation-hygienic characteristic of the protected zones of peaceful nuclear explosions in the Arkhangelsk region

The article presents data on the radiation situation on the territories of the protected zones of peaceful nuclear explosions «Globus-2», «Agat» and «Rubin-1» based on the results of field studies in 2020. Peaceful nuclear explosions were conducted in the Arkhangelsk region for seismic exploration. The results of the radiation-hygienic state of protected zones and radiation safety in the territories adjacent to peaceful nuclear explosions are analyzed by the main indicators: the values of the ambient dose equivalent of gamma radiation, the identification of gamma-emitting radionuclides in situ by field gamma spectrometry, the specific activity of technogenic radionuclides in the soil and tritium in the water of reservoirs and drinking water sources. An assessment of the sanitary condition of the studied territories of protected zones of peaceful nuclear explosions is given. It was found that the levels of the ambient dose equivalent rate of the gamma radiation at all sites are at the level of fluctuations in the natural regional radiation background in the range of 0.08-0.20 microSv/h. On the territory of the protected zone of the peaceful nuclear explosion «Globus-2» were repeatedly identified areas of minor local soil contamination with ¹³⁷Cs (the previous study was performed in 2011). Increased values of the ambient equivalent dose rate of gamma radiation (0.20 -0.22 μSv/h) and specific activity of ¹³⁷Cs in two soil samples (154 and 160 Bq/kg, respectively) were found in these areas. The tritium content in the water of water supply sources does not exceed 5 Bq/kg. These values are typical for global levels of this radionuclide in water bodies. Remains of technological equipment were found on the territories of the protected zones of the peaceful nuclear explosions (especially in the protected zone of the explosion «Agat»), as well as rusty metal pipes and barrels, the remains of wooden structures, etc. Information signs installed on dilapidated concrete foundations at the mouths of combat wells of all surveyed peaceful nuclear explosions have subtle inscriptions. The presence of forest thickets in the places where the investigated peaceful nuclear explosions are conducted and their ignition during forest fires is a potential threat to the release of technogenic radionuclides during depressurization of the mouths of combat wells.

1. Modern radioecological situation in the field of peaceful nuclear explosions on the territory of the Russian Federation / PCs. authors; under hands. Prof. V.A. Logacheva. Moscow; 2005. 256 p. (in Russian).

2. Soviet nuclear tests. Volume 4. Using nuclear explosions to solve economic tasks and research / PCs. the authors hand. V.N. Mikhailov. Sarov: VNIIEF; 2000, 200 p. (in Russian).

3. Peaceful nuclear explosions: General and radiation safety when they hold/ PCs. authors; under hands. Prof. V.A. Logachev. Moscow; 2001. 519 p. (in Russian).

4. Kasatkin VV, Ilichev VA, Kamnev EN, Kasatkin AV, Samorodova TS. Geological and radioecological problems of the objects formed by peaceful nuclear explosions – special radwaste repositories. Atomnaya energiya = Atomic Energy. 2012;113(5): 289-293. (In Russian).

5. Repin VS, Ramzaev VP, Khramtsov EV. The role of protected zones in ensuring the radiation safety of the population living in the areas of peaceful nuclear explosions. Proceedings of the International Scientific and Practical Conference «Actual Issues of Radiation Hygiene»1-3 October 2012, Saint Petersburg, Russia. Saint Petersburg: NIIRG; 2012. P. 109-112. (In Russian).

6. Kiselev GP, Bazhenov AV, Kiseleva IM, Druzhinin SV. Radioactivity of epicentral zones of industrial nuclear explosions in Arkhangelsk region. Vestnik Severnogo (Arkticheskogo) federalnogo universiteta. Seriya: estestvennye nauki = Vestnik of Northern (Arctic) Federal University. Series «Nature Sciences». 2014;4: 21-31 (In Russian).

7. Zelentsova SA, Arkhangelskaya GV, Zykova IA, Khramtsov EV, Zelentsov IG. Public attitude to consequences of peaceful nuclear explosions in Arkhangelsk region. Radiatsionnaya Gygiena = Radiation Hygiene. 2012;5(2): 14-19. (In Russian).

8. Vilegodsky state natural biological reserve of regional significance: Proceedings / Com. on the ecology of Arhang. Region; ed: E.V. Shavrina. Arkhangelsk; 2007. 62 p. (In Russian).

9. Ramzaev VP, Repin VS, Khramtsov EV. Peaceful underground nuclear explosions: current issues on radiation safety for general public. Radiatsionnaya Gygiena = Radiation Hygiene. 2009;2(2): 27-33. (In Russian).

10. Ramzaev VP, Medvedev AYu, Repin VS, Timofeeva MA, Khramtsov EV. Radiation monitoring the industrial nuclear explosion sites and evaluation of the doses to the critical groups of population. Radiatsionnaya Gygiena = Radiation Hygiene. 2010;3(1): 33-39. (In Russian).

11. Journal of the International Commission on Radiation Units and Measurements, Report 53, Volume os27, Issue 2, 1 December 1994.

12. International Commission on Radiation Units and Measurements: Report 53. Gamma-ray spectrometry in the environment / ICRU, 1994. Guidelines for monitoring nuclear or radiation accidents. IAEA, Vienna. IAEA-TECDOC-1092/R.ISSN 1011-4289. IAEA, 2002.

13. Radiation situation in the territory of Russia and neighboring states in 2019. Annual. Obninsk; 2020. 340 p. (In Russian).