Figure 1 shows the basic procedures in disposing
nuclear powered submarines. In essence, they are similar in both countries.
We pay an attention to the substantial differences.
The first reason is that the naval facilities for temporary storage of spent nuclear fuel are full. According to the conclusions, released by the governmental committee in the spring of 1993, more than 30,000 spent nuclear fuel assemblies were placed at the naval storage facilities, which corresponds to nearly 140 reactor cores. The facilities were overfilled. By now, the situation has not been improved. It should be noted, that the naval facilities were constructed in such a way, that storage of spent nuclear fuel was supposed no longer than for 5 years. Part of the spent fuel assemblies are currently placed outdoors at open cites. Some of the storage facilities, for example, like one at Andreyeva Bay of the Northern Fleet, have suffered radiation accidents and currently are not operational.
Beginning 1989, annual delivery of spent nuclear fuel from submarines to the naval storage facilities was constantly exceeding shipments of the fuel to the reprocessing plant "Mayak" from the Navy. According to the data by Norwegian environmental organization "Bellona', this practice initiated even earlier in 1984. The situation aggravated after 1992, when the Gosatomnadzor had prohibited use of obsolete containers of TK-11 and TK-12 types for fuel transportation. At the time being, new containers of TUK-18 type only are permitted for shipment of the spent fuel to "Mayak". The only existing train of 4 special cars allows to deliver less than 12-15 reactor cores annually to the reprocessing plant . At the same time, nearly 30 reactor cores of spent nuclear fuel are removed annually due to submarine inactivation and planned refueling of operational submarines.
Another problem of the slow rate of defueling is related with the fact that eight of the eleven existing service ships for submarine reactor refueling procedures are in a bad technical condition, because they have been operated for more than 25 years. New ships of project 2020 ("Malina" class) are built very slowly because of lack of financing. They are supposed to replace the old service ships.
Fuel removing is going slowly also because practically all existing shore-based and floating storage facilities for solid and liquid radioactive wastes are full. According to estimates of experts of the Russian Academy of Sciences, routine submarine operations and activities of related infrastructure create almost 6000 cubic meters of solid wastes and 15000 cubic meters of liquid radioactive wastes annually. There is a lack of facilities and resources for proper reprocessing and burying these radioactive wastes.
In spite that the reactors of decommissioned nuclear powered submarines are shut down, they represent a potential danger as long as their fuel is not removed. Tough, these reactors are under strict control, and the probability of accidental chain reaction is negligible, experts do not exclude a possibility of radioactivity leakage from the reactors as a result of environmental disasters, mistakes of the personnel or a sabotage. Besides that, a long delay in defueling may substantially complicate the process of removing the fuel assemblies in future, because the assemblies and elements of the reactor may be damaged.
In order to decrease the radiation danger, and exclude a possibility of a reactor accident during defueling operation, experts propose to store the spent fuel inside "dried" reactors of decommissioned submarines. In any event, slowness in removing spent fuel from submarine reactors will lead to additional expenses and complicate speeding up the rate of submarine disposal.
It must be noted, that many Russian experts suggest, that reprocessing of the spent submarine fuel is impractical. Removed fuel contains substantial amount of uranium (U-235). It is this fact to have been the major argument, that spent fuel of submarine reactors was reprocessed. After reprocessing, the obtained uranium was used in the nuclear energy cycle for fabrication of fuel for RBMK-1000 type reactors of civil nuclear power plants. These days, when considerable amount of "fresh" uranium is available due to dismantling the Russia's nuclear arsenal, reprocessing of spent submarine fuel is not profitable anymore. Opponents of reprocessing suggest, that special facilities should be built to place the spent fuel for long term storage until "clean" and environmentally safe reprocessing technologies emerge. It is already apparent, that significant part of the spent fuel is not subject to reprocessing. This is the fuel of the liquid metal submarine reactors (9 reactor cores) and almost 10% of the fuel of pressurized water reactors currently stored at naval bases (according to "Bellona", this fuel represents damaged assemblies and the fuel of accidental reactors ),
However, differences exist in sequences of further operations of submarine disposal. In the US, inactivation of submarines is carried out at five ship repair facilities of the West coast. Most of the inactivated submarines are prepared for transportation and towed to Pudget Sound Naval Shipyard in Bremerton, Washington. Part of the inactivated submarines is prepared for waterborne storage, so that a watertight hull integrity is established to support a minimum of 15 years of wet storage. In spite of the fact, that most of defueled Russian submarines have to be kept afloat at least for 15-20 years until dismantling, they are rarely undergone appropriate operations for waterborne storage. As a result, a personnel has to be kept aboard the submarine, in order to prevent sinking the ship near its pier.
Removal of the reactor compartment from a submarine is performed at Pudget Sound Naval Shipyard only. The cutting technology is in fact similar to the one applied in Russia. For this purpose, torches, hand held saws, pipe cutters, and grinders are used in the US.
Having been cut, a reactor compartment is load on a barge and transported along the West coast and Columbia river to DoE's Hanford Nuclear Reservation in Washington state. The final stage of transportation is carried out by multiple wheel high capacity trailers. Reactor compartments are placed in a specific trench at Hanford Site for indefinite storage. Experts conclude, that it will take at least 600 years before the first pinhole penetration of some lead containment areas of the reactor compartment packages. It will take several thousands years before a leakage of remaining radioactivity in the reactors becomes possible.[5-7]
So far, there are no equipped long term storage facilities in Russia to place removed reactor compartments and keep them under control. As a rule a three compartment section is cut, which consists of the reactor and adjoining compartments of a submarine. Such sections are prepared for "wet" storage and transported to a specific place to be kept afloat. There is also a practice, when one (the reactor compartment) or multi-compartment (8-10 compartments of a submarine's inner hull) watertight sections are stored afloat.
Disposal of submarines with accidental reactors represents a specific problem in Russia. There are three and two accidental submarines correspondingly with the Pacific and the Northern Fleets. According to experts, the fuel of some of these submarines can not be removed by existing technical means. Managing reactor compartments of the accidental submarines needs specific technologies as well.
Thus, recycling of the remaining submarine sections is not profitable in the U.S. In 1990-s, reusing of scrap metals was widely thought to cover the submarine recycling costs in Russia, provided that the expenses on spent nuclear fuel and radioactive wastes management are not taken into account. There is no information in the open literature to what extent proper disposal of non-radioactive hazardous wastes is performed in Russia, while the remaining submarine sections are recycled.
By the end of 1994, there were 180 nuclear powered submarines built
in the US. Nearly 80 of these ships were decommissioned, and 43 reactor
compartments were cut and placed at Hanford Nuclear Reservation.
There are plans to dispose all submarines built before mid-1970-s (pre-"Los
Angeles" and pre-"Ohio" classes) by the next century. This program will
cost $ 2.7 billion, so that expenses per unit submarine will be $ 25-40
million. Besides that, in 1995, the draft program
was prepared to dispose submarines of the third generation ("Los Angeles"
and "Ohio" classes), nuclear powered cruisers, most of which have been
already decommissioned. The cost of the program is estimated as $ 1.5 billion
, if the current scheme of submarine disposal is adapted. The variant,
which assumes recycling reactor compartments and re-use of the metal of
the reactor compartments will cost nearly $ 9.4 billion.
Current situation in Russia is much more complicated. By the end of 1995 nearly 250 nuclear powered submarines were built. More than 150 of them were decommissioned by the fall of 1996. Spent fuel was removed from reactors of one third of decommissioned submarines (52 submarines). Nearly 20 reactor compartments were removed and placed afloat. Nearly 10 sections (these consist of 8-10 compartments of the submarine inner hull including the reactor compartment) were prepared for "wet" storage before 1989.
It must also be noted, that, since 1993, the rate of submarine decommissioning was significantly exceeding the rate of defueling and removing the reactor compartments. The basic reason is well known - the scarce funds allocated to submarine inactivation and disposal, so that all previously adopted governmental programs have failed.
Figure 4 illustrates anticipated prospective, unless
current trends are changed. Even if the reactors of 10 submarines are defueled
annually, i.e. the current defueling rate is doubled, the problem of spent
fuel removal will not be solved sooner than in 20 years. Simple calculations
can show, that in order to solve the problem of reactor compartments removal
by 2010, current rates should be increased at least by the factor of 4-5.
1. The problem of submarine disposal has become the one to be considered of the highest priority in Russia. However, there is an impression, that Russia's government continues to ignore this fact by providing scarce financing. The analysis of the US program shows, that significant resources are needed for rehabilitating the environment and population from the consequences of nuclear powered submarines exploitation. Russia will probably have to pay much more compared to the US, taking into account the fact, that it does not have an adequately developed infrastructure to solve these problems. In addition, Russia has to deal with the effects of careless and insufficiently considered actions in maintenance of nuclear powered submarine fleet in the past. [1-4]
In particular, in 1995, experts estimmated, that major construction work would cost more than 90 trillion Russian Rubles. In order to solve the problems of spent nuclear fuel management, Russia would need at least 30-40 years and 2.6 trillion Russian Rubles of financing. Necessary funding for removal the submarine reactor compartments and disposing remaining submarine sections was estimated as 8 trillion Russian Rubles (160 submarines x 50 billion Russian Rubles).
2. The documents representing the US program of nuclear submarine inactivation and disposal [5-7] are publicly available, and they give clear answers to the following questions:
3. It will apparently take several dozen years in order to accomplish a feasible submarine disposal program. Though, importance of other measures should not be detracted, we think, that the priorities must be given to the following tasks.
The authors would like to thank W.
Alton Jones Foundation for financial support, which has substantially
promoted accomplishing this project. We thank Joshua Handler from Princeton
University for his help in our study.
2. Bukharin O., Handler J. Russian Nuclear-Powered Submarine Decommissioning, Science and Global Security, 1995, vol. 5, pp.245-271.
3. Nilsen T., Kudrik I., Nikitin A. The Russian Northern Fleet. Sources of Radioactive Contamination., "Bellona" report, # 1, 1996.
4. Problems of Decommissioning and Disposal of Nuclear Powered Submarines, International Seminar, held in Moscow on June 19-22, 1995. Abstracts. Moscow, 1995.
5. U.S. Naval Nuclear Powered Submarine Inactivation, Disposal, and Recycling, September 1993, United States, Department of the Navy.
6. Draft Environmental Impact Statement on the Disposal of Decommissioned, Defueled Cruiser, Ohio Class, and Los Angeles Naval Reactor Plants, August 1995, United States, Department of the Navy
7. Nuclear Submarines - Navy Efforts to Reduce Inactivation Costs. US General Accounting Office Report, July 1992, GAO/NSIAD-92-134
8. Miasnikov E., Military Nuclear Powered
Ships, In Nuclear Encyclopedia, ed. by A. Yaroshinskaya, Yaroshinskaya
Charitable Fund, 1996, pp. 148-159 (in Russian).