. Closing of the Semipalatinsk underground nuclear test site, Kazakhstan: Aug 1991

. only currently declared (1993) Russian test site: NZ

. Paper reviews geologic data on NZ published in various books and Journals over a period of 70 years

. For OSI: presented data usefull for estimating the coupling characteristic of the rock, potential for decoupling , comparisons with the geology of othr nuclear test sites worldwide

. Between 1964 and 1990, 36 underground tests have been conducted at this test site

. The Matochkin Shar test site has not been as active as the test sites in eastern Kazakhstan deactivated 1991

. Underground nuclear testing at the Matochkin Shar site occurs in low-porosity, metasedimentary, fractured and faulted rocks in a permafrost environment

. Conditions under the U.S. has no previous test experience

.Themajority of tests appear to have been conducted in clastic rocks, though some mapped test epicenters are located on stratigraphic units composed mostly of carbonates

. In spite of scaled depths of burial similar to those used at he U.S. test site, a large number (72%) of tests at Matochkin Shar resulted in seepage of radioactive inert gases into the atmosphere, suggesting that the testing media do not provide reliable, complete containment of radioactive explosions products