The Comprehensive Test Ban Treaty is a multilateral arms control Treaty negotiated in the mid-1990s which sought to ban all nuclear weapons tests. In October 2023, President Vladmir Putin directed the revocation of Russian ratification of the Comprehensive Test Ban Treaty (CTBT), which Russia’s rubber-stamp Duma promptly did. As early as March 2023, Putin hinted Russia might resume nuclear testing. Much of the media commentary takes Russia’s hedged claim that it will not resume nuclear testing at face value. Putin has indicated that “…if the United States conducts a nuclear test, we will also carry it out.” This apparently will be the bogus political rationale for resumed Russian nuclear testing. In October 2023, Mikhail Ulyanov, Russia’s envoy to the United Nations in Vienna, stated that, “Never say never. Tests may resume under certain circumstances.” (Emphasis in the original), Russian Deputy Foreign Minister Sergei Ryabkov was more specific, saying resumed Russian nuclear testing would be a response to U.S. nuclear tests.
The legal implication of Russia’s revocation of CTBT ratification is quite important in the context of the current nuclear crisis generated by Russia’s invasion of Ukraine. Under the Vienna Convention of the Law of Treaties, Russia’s revocation of the CTBT ratification eliminates the legal obligation not to defeat the object and purpose of the Treaty. This opens the legal possibility of high-yield nuclear testing by Russia. The ridiculous Russian claims that the Biden Administration plans to resume nuclear testing appear to be aimed at creating a fake political rationale for resumed high-yield nuclear testing. Reportedly, satellite imagery indicates that Russia has “built new facilities and dug new tunnels” at its Novaya Zemlya nuclear weapons test site. Resumed high-yield nuclear testing may very well happen in light of: 1) the persistent Russian nuclear threats since its 2022 invasion of Ukraine, 2) the value Russia places on its nuclear capability, 3) its political agenda of recreating the Soviet Union, and 4) its ultimate political objective of dominating Europe. A nation that would initiate the use of nuclear weapons for the first time since World War II clearly wants to be certain that they will work as expected, which can only be accomplished by nuclear testing.
By “high-yield” nuclear testing I do not mean “high yield” (approaching a megaton) as the Atomic Energy Commission and the Department of Energy would have characterized it during the Cold War. Rather they would be “high” in the context of the covert low-yield nuclear testing that Russia has conducted in violation of its legal obligations under the CTBT probably for the last twenty years or more. Both the Trump and the Biden Administrations concluded that Russia has conducted covert low-yield nuclear tests in violation of the CTBT and the Threshold Test Ban Treaty (TTBT). (The TTBT is a bilateral arms control agreement negotiated between the Soviet Union and the United States in the 1970s which banned underground nuclear tests with yields of over 150-kilotons. The TTBT requires notification of nuclear tests and has a substantial verification regime.)
If Russia resumes high-yield nuclear testing, the key issue will be whether Russia announces or cares whether the nuclear tests are detected and presumably become public. It is impossible to know which way President Putin would go. If Russia plans to announce nuclear testing or does not care whether the nuclear tests are detected, there is almost no limit on what testing yields could be. Clearly, the higher the yield, the higher the cost. However, the potential savings in the cost of Russian modernization would more than offset the cost of the tests. The Threshold Test Ban Treaty would in theory limit testing to 150-kilotons but this is one of the treaties that Russia has been violating. Russia may depend upon the near certainty that the arms control enthusiast community and the left-wing seismological community would be in denial concerning the reality of a barely detected Russian nuclear test. The behavior of the Biden Administration suggests it will do nothing other than verbal denouncements in response to resumed Russian high-yield nuclear testing. Indeed, its 2022 Nuclear Posture Review report called for ratification of the CTBT, despite the fact that the Administration’s own 2022 State Department report on arms control compliance reported Russian violations of the CTBT.
All yield producing nuclear tests (supercritical tests) provide benefits regarding nuclear weapons sustainment and modernization compared to non-yield producing (subcritical) experiments. Generally speaking, the higher the yield, the greater the benefits. Resumed Russian high-yield nuclear tests could be anywhere from sub-kiloton to hundreds of kilotons.
There are large advantages from high-yield nuclear testing in maintaining an existing nuclear stockpile and it is very important for the type of nuclear modernization Russia is conducting. There are significant verification problems associated with the CTBT. During the Senate hearings on the CTBT, Ambassador C. Paul Robinson, then-Director of the Sandia National Laboratory and Chief of Delegation to the United States CTBT negotiations, cautioned that, “If the United States scrupulously restricts itself to zero yield while other nations may conduct experiments up to the threshold of international detectability, we will be at an intolerable disadvantage.” This is the reason that CTBT is the only arms control treaty ever to be rejected by a majority vote in the United States Senate.
Covert tests of several kilotons and possibly as high as 10-kilotons are possible using techniques such as: 1) nuclear testing outside of known nuclear weapons test sites, 2) decoupling (testing in tunnels with a large cavity to reduce the seismic signal) or 3) decoupling combined with testing in salt mines These techniques are more expensive and inconvenient than overt nuclear testing at test ranges but they are certainly possible. Indeed, Russia may already be doing more than low-yield testing and the higher-yield tests simply have not been detected.
The lowest yield type of nuclear tests are called hydronuclear tests which cannot be detected by seismic means. The 2002 report of the National Academy of Sciences on CTBT verification said:
At the lower end of the very-low-yield category, Russia could develop and test new very-low-yield tactical weapons in the range of 10 to 100 tons. With respect to seismic detection, the 10-ton weapon could confidently be adequately tested under decoupling conditions even at Novaya Zemlya [Russia’s nuclear test site], and might even be tested in a steel or composite containment so that it would give no ground shock at all. Indeed, with its experience in testing and weapons design, Russia could develop a 10-ton nuclear weapon using only hydronuclear tests in the kilogram-yield range, and be reasonably confident of its performance.
In April 1999, President Boris Yeltsin reportedly authorized conducting “hydronuclear field experiments.” In the same month, then-First Deputy Atomic Energy Minister Dr. Viktor Mikhaylov stated that Russia would conduct “so-called test-site hydronuclear experiments, where there is practically no release of nuclear energy,” and that “…developed traditional nuclear powers can use hydronuclear experiments to perform tasks of improving reliability of their nuclear arsenal and effectively steward its operation.” (Emphasis added). In July 2001, when Dr. Mikhaylov was Director to the Sarov nuclear weapons laboratory, he reiterated that “…the developed, traditional nuclear powers, using hydronuclear experiments, can perform the task of improving reliability of the nuclear arsenal and effectively track its operation while reducing the risk of possible accident.”
During the Mikhaylov era, the Russians spoke repeatedly about hydronuclear tests apparently because Mikhaylov was trying to legitimize them under the CTBT. When he was Atomic Energy Minister, Dr. Mikhaylov co-authored a publication which revealed that most of the 89 Soviet hydronuclear tests were under 100-kg explosive yield, but the report gave no indication what the highest yields were. Based on Russian statements concerning Soviet nuclear testing a reasonable guess about how Russia defines hydronuclear tests might be a ton of TNT. (In June 2000, Nikol Voloshin, a senior official of the Ministry of Atomic Energy said, “The [nuclear] ammunition we have developed ranges in power from tons to megatons of TNT equivalence.” [Emphasis added.]) The Mikhaylov report on Soviet hydronuclear testing said that two of the Soviet-era nuclear tests were airburst, suggesting a rather elastic definition of a hydronuclear test (i.e., the yield Russian experts think they need to test at). In 1999, Dr. Mikhaylov stated, “Determining the limits of ‘authorized activity’ is no simple process and only professionals can direct it correctly.)”
In January 2016, Dr. John Foster, former Director of the Lawrence Livermore National Laboratory and probably the greatest U.S. nuclear weapons designer,[1] stated that hydronuclear tests “of less than one ton” yield can provide high confidence in the “performance [of nuclear weapons] at low yield.”[2]
Higher yield testing up to the threshold of detectability using the available concealment techniques offer substantially greater advantages. Ambassador C. Paul Robinson, former Director of the Sandia National laboratory and the Chief U.S. negotiator in the CTBT negotiation, said, “At that time [1995], we in the U.S. labs requested that the permitted test level should be set to a level which is, in fact, lower than a one-kiloton limit, which would have allowed us to carry out some very important experiments, in our view, to determine whether the first stage of multiple-stage devices was indeed operating, successfully.” Higher yield tests provide even greater benefits. According to Siegfried Hecker, a former Director of the Los Alamos National Laboratory, “[M]ost [new] designs could be adequately tested at yields between one and ten kilotons.”
Nuclear testing at full yield or at a significant fraction of full yield would obviously result in the greatest benefits with regard to assessing reliability, improving knowledge of the physics involved, and the development of new weapons but it is probably not necessary compared to testing at say tens of kilotons.
Other than denouncing Russia’s resumed nuclear testing, the Biden Administration will almost certainly do nothing in response to even overt Russian nuclear testing and may even attempt to coverup these tests, if possible. There will almost certainly be assertions that the United States does not have to conduct nuclear tests because of the success of the stockpile stewardship program. These assertions have little to back them up since there is no way to prove them, absent nuclear testing. In 2008, then-Secretary of Defense Robert Gates assessed the situation as follows: “To be blunt, there is absolutely no way we can maintain a credible deterrent and reduce the number of weapons in our stockpile without either resorting to testing our stockpile or pursuing a modernization program.” The United States has not resumed nuclear testing. The reference to the “modernization program” was a proposal to develop more robust types of nuclear warheads called the Reliable Replacement Warheads. This was not done until possibly the recent W93 warhead program. The W93 may be a more robust design although the official description of the warhead does not mention this. Even if the W93 is a more robust design, it could not compare to the reliability of a Russian nuclear weapon subject to contemporary high-yield nuclear testing. Russia will be certain that its nuclear weapons work while the United States believes that ours do. In addition, nuclear tests have considerable implications for understanding nuclear weapons effects and testing equipment against these effects.
Resumed nuclear testing by Russia could easily become nuclear testing by Russia and China. While China probably has covertly conducted nuclear tests, it would probably gain even more than Russia from high-yield nuclear testing. The current relationship between Russia and China could certainly result in a joint program to exploit resumed Russian nuclear testing. This has to be viewed in the context of the two peer nuclear threats the United States and its allies now face.
This story originally was published by Real Clear Wire.
