Tritium in well waters, streams and atomic lakes in the East Kazakhstan Oblast of theSemipalatinsk Nuclear Test Site

Abstract

The concentration of tritium has been determined in well waters, streams and atomic lakesin the Sarzhal, Tel’kem, Balapan and Degelen Mountains areas of the Semipalatinsk TestSite. The data show that levels of tritium in domestic well waters within thesettlement of Sarzhal are extremely low at the present time with a median value of4.4 Bq dm−3 (95% confidenceinterval: 4.1–4.7 Bq dm−3). These levels are only marginally above the background tritium content in surface watersglobally. Levels in the atomic craters at Tel’kem 1 and Tel’kem 2 are between one and twoorders of magnitude higher, while the level in Lake Balapan is approximately12 600 Bq dm−3. Significantly, levels in streams and test-tunnel waters sourced in theDegelen Mountains, the site of approximately 215 underground nucleartests, are a further order of magnitude higher, being in the range133 000–235 500 Bq dm−3. No evidence was adduced which indicates that domestic wells in Sarzhal arecontaminated by tritium-rich waters sourced in the Degelen massif, suggesting that thelatter are not connected hydrologically to the near-surface groundwater rechargingthe Sarzhal wells. Annual doses to humans arising from the ingestion of tritiumin these well waters are very low at the present time and are of no radiologicalsignificance.