International Control of Tritium for Nuclear Non-Proliferation and Disarmament
by Martin B. Kalinowski
The book is issued as Volume IV in the Science and Global Security Monograph series, a series with the explicitly expressed aim to publish high-quality technical and scientific analyses related to arms control and security policy.
Even though the book to some extent deals with political issues in the form of multilateral and bilateral treaties and agreements, and tritium control through national legislation, the main focus is on technical and scientific issues. Thus, the monograph falls well within the above cited scope of the series. Most nuclear weapons of all recognized nuclear weapon states are believed to contain tritium, and warheads containing tritium can be built smaller and lighter while retaining the same yield. This fact represents the technical and scientific background for suggesting international control of tritium for nuclear non-proliferation and disarmament.
In Chapter 1 the physical and chemical properties of tritium are summarized, and civilian and non-nuclear military applications are listed. Very briefly the function of tritium in nuclear warheads is described. For non-nuclear experts, the latter topic could with benefit have been outlined in greater detail. Another minor critical comment refers to the main physical data on tritium presented in Table 1.1 of the book. Here, a dose figure of 1.19 mSv/day resulting from 1 GBq tritium in man is given, which is correct for 1 GBq body content. However, health physics aspects are usually expressed in terms of committed dose from a particular intake, and the appropriate figure of approximately 20 mSv for a 1 GBq intake could also have been listed.
Further in Chapter 1, the current state of tritium control at the national and international level is described in some detail. In this context, a very recent initiative from IAEA as regards the strengthening of the import/export control of non-nuclear radiation sources from a radiation safety and security point of view could be mentioned. So far this initiative does not include open radioactive sources like tritium, but the principle may very well be extended to include these kind of sources as well.
In Chapter 2, a comprehensive analysis of diversion paths, i.e. clandestine production or illegal removal paths, are presented. All diversion paths by which a significant quantity of 1 gram per year can be acquired are considered in the analysis. Altogether 55 different paths are described, five of which do not exceed the critical production rate. The most relevant paths to illegally produce pure tritium in significant quantities are those that are based on the positioning of large quantities of raw material with a high cross section for tritium production in a high neutron flux. In this context the insertion of lithium-6 into a nuclear reactor may be the preferred technique. Among the diversion paths a number of tritium removal paths are listed. Larger quantities of tritium are available in heavy water and spent fuel, but the number of facilities in the world where the proper amounts of tritium are extractable is very small.
In Chapter 3, methods and goals for verification of an international tritium control agreement are discussed, in terms of verification of non-production and non-removal from existing and declared inventories. A table lists the various facility types worldwide which are relevant for tritium control. Of a total number of 956 facilities in 1992, almost 80 % are linked to nuclear power reactors or research reactors. A thorough list of appropriate inspection activities by facility types is presented. At nuclear reactors, verification of non-production is already covered by the existing nuclear safeguard procedures as carried out by IAEA and EURATOM, and the author concludes that unreported breeding of tritium up to 100 g/y would be detectable by those nuclear safeguards activities which are already implemented in order to detect unreported breeding of plutonium. Verification if non-removal can partly rely on IAEA safeguards for heavy water to the extent that these are actually implemented, and illegal removal from spent fuel containing more than 0.2 g of tritium would be detected with the existing control measures. The author thus concludes that verification of non-diversion of tritium is feasible at reasonable costs, and that the control regime would have to be applied to a limited number of facilities ( up to some 50).
In Chapter 4, the technical assessment of an international tritium control agreement is made. The politically required verification effectiveness may be lower for tritium than for nuclear safeguards in general, as tritium is not necessary for the production of first-generation nuclear weapons. The author concludes that all diversion paths which could yield more than 1 g of tritium within the desired detection time of 1 year can be covered by state-of-the-art control measures. Thus, it is suggested to expand the scope of the nuclear nonproliferation regime to include tritium. For this purpose, the author outlines an international Tritium Control System as well as a verified cutoff for the production of fissile materials and for tritium (Integrated cutoff).
The monograph gives a comprehensive qualitative and quantitative presentation regarding fields of application, production methods, and current status of tritium control. A large amount of data is gathered, and the book may very well serve as a general introduction to the world of tritium and tritium applications. The author further argues convincingly that it is feasible from a physical and technical point of view to implement and to verify an agreement on international tritium control, both to prevent horizontal proliferation and to reverse vertical proliferation.
The monograph is well written, and the topics are presented in an educational manner. Apart from Chapter 1, all chapters end with a conclusion section summing up the chapter content. The monograph is structured into 4 chapters, of which chapter 4 is a short chapter with only one sublevel repeating many of the major statements and conclusion of the previous chapters. The other chapters are structured in two sublevels, and to some extent even a third level with a separate heading is used. Chapter 1 in particular covers a great number of different topics. In order to improve the readability, the monograph would have benefited from a broader horizontal and a reduced vertical proliferation, i.e. from being structured into more chapters with fewer sublevels.
Tor Wøhni
