https://declassified.library.utoronto.ca/files/original/a280d658ee889bd0ec4ce5bab9074593.pdf e846b6de9d2408828162c5f62f9651df PDF Text Text Document disclosed under the Access to Information Act DocumentjdiRQlgpe en vertu de la Loi sur I'acces a I'information SECRET M E M O R A N D U M V 2080-1 (DSTI) V 3145-1 15 Apr 66 DGP COMPREHENSIVE TEST BAN TREATY Reference: a. V3145-1 (DLRP) of 30 Mar 66, attached b. External Affairs letter of 22 Mar 66. 11X1-1 •mt" !• Because of the complexity of the issues involved, it is impossible for us to provide brief categorical answers to the questions posed in reference b. Since Canadian scientists and engineers have not been permitted to work on the design of neclear weapons and do not have access to US and UK weapons design data,, it follows that our knowledge of the state-of-the-art of nuclear weapons is sketchy. This also applies to the more sophisticated elements of ABM systems. Our judgements therefore are based largely on impressions received from discussions in the US and UK and on our interpretation of accumulated pieces of information, rather than on full knowledge of the facts. 2. The eleven questions listed on pages 2 and 3 of the letter from External Affairs should be answered in detail by the Director of Atomic Research, DRB and by the Seismology Division of the Dominion Observatory, both of whom have received similar letters. We feel it\ appropriate, however, to comment briefly on the first three questions. 3. What is the threshold above which we can now identify all seismic events in the Soviet Union? - In our view there is no absolute threshold above which all seismic events in the USSR can be positively identified with 100% certainty. However, one can speak of seismic magnitudes above which one would hope to be able to detect and identify the majority of seismic events with reasonable certainty. The presently-existing combination of overt and covert*") western seismic stations is believed to be capable of detecting and identifying the majority, say 85% or so, of seismic events in the USSR above magnitude 4.75 (m 4.75). This corresponds roughly to closely-coupled, or tamped, underground nuclear tests ranging in yield from 10 to 100 KT, depending on the medium in which they are conducted, i.e. (1) If conducted in a highly elastic, non-spongy medium like granite, the majority of Soviet tests above 10 KT can probably to detected and identified. (2) If conducted in a non-elastic, spongy medium like alluvium, the majority of Soviet tests above 100 KT can probably be conducted and identified. (3) If conducted in a medium of intermediate elasticity, the "high-certainty" threshold is probably between 10 and 100 KT. ...12 000038 �SECRET Document disclosed under the Access to Information Act Document divulgue en vertu de la Loi sur I'acces a I'information - 2 - 4. Is this threshold likely to be lowered significantly in the near future? - With the expected deployment of more large aperture seismic arrays (LASA), as well as ocean-bottom and deep well seismometers, the above threehold of m 4.75 could probably be lowered to m 4 in the near future. This corresponds roughly to the detection by the West of the majority of closelycoupled Soviet underground nuclear tests ranging in yield from 1 to 10 KT. 5. Could the Soviet Union undertake a series of tests underground without at least one test registering unmistakably on a seismometer outside Soviet territory? - The likelihood of an entire series of tests in the USSR completely escaping detection is probably small, although in the case of a low-yield test series there might be considerable uncertainty as regards positive identification. Also it might be possible for the USSR to attempt to muffle or decouple the higher-yield tests by conducting the detonation in large caverns. Such a procedure would be expensive and time-consuming and would also result in much above-ground activity which might be detected in one way or another by intelligence sensors. Large abandoned mines might however be useful for this purpose. 6. Could the Soviet Union make significant advances in nuclear weapons technology on the basis of isolated tests, not in series? - What increased costs and difficulties would there be to achieve the same results in single tests? If past history can be used as a guide, then we believe the USSR could make significant advances in nuclear weapons technology on the basis of isolated tests. There are several tests in the Soviet nuclear weapons development program to date which substantiate this belief. For example, on the basis of a single thermonuclear test in August 1953, the USSR was apparently able to weaponize and stockpile at least a limited number of first-generation "hydrogen bombs" for heavy bomber delivery. In order to continue achieving significant advances with single tests, a country would of course be forced to do much more homework, more laboratory work, more prototype and mock-up studies, etc. We have no way of gauging the increased cost and difficulties, apart from a possible time penalty. 7. The four questions listed on pages 3 and 4 of the letter from External Affairs should be answered in detail by the Director General of Operations Research, whose personnel have been studying the ABM program and related consideration in some detail in recent years. Hdwever, we would like to make the following comments on these questions. 8. How valid is the USA military argument that the USA should continue testing to improve its nuclear warheads both for the strategic deterrent and for a possible ABM system? - Our discussions over the past year with personnel in the US intelligence and defence communities would lead us to judge that the argument for maintaining at least a minimum test option is valid. It is our understanding that US weapons designers'feel that a great deal of work still needs to be done to improve the invulnerability of US ICBM warheads to a variety of possible Soviet defensive measures, such as X-ray kill, neutron heating, laser damage, etc. They feel that the actual tests of such improved or "hardened" warheads, probably in lower-yield versions, will be necessary from time to time to ensure that the US remains ahead of the USSR in the seesaw battle of measures and countermeasures. .../3 000039 �Document disclosed under the Access to Information Act Document divulgue en vertu de la Loi sur I'acces a I'information SECRET -.3 9. We also understand that the developments and testing of a relatively light, low-megaton warhead, optimized for X-ray production, is considered essential by the US in the creation of an effective anti-Soviet ABM system. Ideally, such a warhead should be tested in the environment in which it is intended to function, i.e. space., However, being able to test it underground is obviously preferable to not being able to test it at all. A site in northern Nevada is presently being developed by the US for the underground testing of higher-yield nuclear devices; presumably the proposed ABM "X-ray" warhead could be proof-tested here at full yield. 10. To what extent will improve missile systems result from developments in propulsion, targetting, guidance, decoys, etc., and to what extent from further improvements in nuclear warheads? - The in achievement of a given mission effectiveness of kill probability, an improvement in the accuracy of a missile system is roughly proportional to the inverse square of the yield or the inverse square of the number of missiles required. Thus a two-fold improvement in accuracy allows either a four-fold reduction in warhead yield or a four-fold reduction in the number of missiles required. On the average, present Soviet ICBMs are estimated to have a nominal accuracy of 1 n.m. CMP. This is expected to improve to \ n.m. and is likely to be achieved either with improved missileborne guidance equipment or with ground-based radio-assisted techniques. There is some evidence that the Russians are working on the latter method, although ground-based equipment is subject to attack and to electronic interference. Nevertheless, if nuclear testing is prohibited, both the US and USSR could continue to improve the mission effectiveness of their strategic missile systems by concentrating on the improvement of missile guidance. Improved nuclear warheads, which would require nuclear testing, would of course significantly angment the effect of guidance improvements. 11. All presently operational Soviet ICBMs are liquid fuelled and hence not weight-limited with respect to neclear warheads. The US strategic deterrent however is based largely on solid-propellant missiles, which are weight-limited, and there are indications that a trend in this direction is now developing in the USSR as well. Since the solid-propellant missiles developed to date are relatively small with warhead weights of 1500 lbs and yields of 1-2 MT (at best), theyare more suitable for attach against soft targets than hardened targets, unless an attacker is prepared to expand considerable numbers of them. An improvement in quidance and an increase in warhead yield would significantly increase the effectiveness of these systems against hardened targets and permit the use of significantly smaller numbers per target. The achievement of an increased warhead yield at those relatively low warhead weights would require continued nuclear testings. 12. We believe that both the US and the USSR now have target data of sufficient accuracy, so that their ICBM forces are not limited in their effectiveness by targetting considerations. The US is believed to have ail extensive program for the development and testing of decoys and penotration aids. There is no evidence of Soviet testing of decoy systems on their strategic missiles; however, we estimate that their technology is adequate to develop and produce both decoys and penetration aids, if and when they consider these necessary. ...Ik �Document disclosed under the Access to Information Act Document divulgue en vertu de la Loi sur I'acces a I'information SECRET - 4 _ - 13. Do you think it possible or likely that the USA deterrent would lose its credibility if the USSR conducted small clandestine nuclear tests underground leading to some technological improvements? - The US deterrent would only lose credibility if the USSR could achieve some significant technological improvement in the ABM warhead area, i.e. something which would again render US ICBM warheads more vulnerable. It is possible but likely that such improvements could be achieved with very low-yield tests. 14. To what extent is an effective ABM system attainable and how much nuclear testing would have to go into the realization of such a system? - We believe that with some combination of the Nike-Sprint concept and a multimegaton "X-ray" warhead, an effective ABM system is attainable now with the present state-of-the-art. As stated above, some nuclear testing over the next year or two would be essential to complete the development of the most effective ABM warhead. However, the situation never remains static, and a system which may be effective now, could be essentially nullified by a Soviet discovery of some unexpected new method of "hardening" warheads. This in turn would necessitate the development by the US of ABM warheads using a new kill mechanism. From this point of view therefore, the option for some form of nuclear testing needs to be kept open. 15. To what extent will the growth of Communist China as a neclear power affect the USA need for an ABM system? - For at least the nect ten and possibly twenty years, the slowly-growing military threat of Communist China to North America could probably be effectively countered by a limited US deployment of a relatively unsophisticated ABM system. For this purpose, the 200 KT "neutron-kill" warhead developed and tested for the Nike-Zeus system would probably be quite adequate. Original Signed by L. Guy Eon (L.E. Kenyon) Brigadier Director-General of Intelligence. JKoop (2-8388)mo Dist: orig/circ/DSTI/file retyped (8«D checked &V\) � Text A resource consisting primarily of words for reading. Examples include books, letters, dissertations, poems, newspapers, articles, archives of mailing lists. Note that facsimiles or images of texts are still of the genre Text. Dublin Core The Dublin Core metadata element set is common to all Omeka records, including items, files, and collections. For more information see, http://dublincore.org/documents/dces/. Identifier An unambiguous reference to the resource within a given context CDBM00011 Title A name given to the resource Memo Date A point or period of time associated with an event in the lifecycle of the resource 4/15/1966 Source A related resource from which the described resource is derived RG25-A-3-c, file 27-11-7, "DEFENCE - CONVENTIONAL AND NUCLEAR ARMAMENTS - ANTI - BALLISTIC MISSILES (ABM) = DEFENSE - ARMEMENTS DE TYPE CLASSIQUE ET NUCLEAIRE - ENGINS ANTIMISSILES (ABM)," vol. 10357, part 1, Library and Archives Canada, (LAC). Creator An entity primarily responsible for making the resource External Affairs Rights Information about rights held in and over the resource Canadian Crown Subject The topic of the resource Anti-ballistic missiles Description An account of the resource Comprehensive Test Ban Treaty Publisher An entity responsible for making the resource available Canada Declassified Type The nature or genre of the resource Text Format The file format, physical medium, or dimensions of the resource PDF Language A language of the resource en