6. NUCLEAR RESEARCH REACTORS AND NUCLEAR RESEARCH CENTERS

6.1. General

The nuclear research centres of the ex-USSR are intended for studies in the fields of nuclear physics, solid state physics, radiation material science, radioisotope production and for the solution of other tasks. Most of them were constructed in the 40s-50s, and the main facilities were put into operation in the late 60s. As a rule these centers were complex systems i.e. they had involved not only the research reactors but also "hot" cells for material tests, research laboratories, radwaste handling facilities, etc. The research reactors installed in the nuclear centers are very diverse in their designs, power levels, material used, operation mode; however it can be noted on the whole that the power levels of these reactors are relatively low, and therefore the RW quantities stored in the nuclear research centers are relatively small. These reactors belong to many different departments.

A brief characteristic of the research reactors is given in Table 6.1.

Table 6.1

The civil-purpose research reactors of the research centers of Russian Federation and of the ex-USSR countries

6.2. Characteristic of accumulated radioactive materials (RM) and radioactive wastes (RW)

In this Section of the Sector the information as for 01.07.95 is given.

6.2.1. Russian Research Centre "Kurchatov Institute"

6.2.1.1. Reactor F-1

This reactor contains 46411 kg of natural uranium in the form of cylindrical metallic slugs, balls and pellets of UO₂ and U₃3O₈, as well as about 41 kg of 2% enriched uranium cylindrical metallic slugs.

The burnup in the natural uranium slugs is 6 kWd/slug, in the 2% enriched uranium slugs it is 2 kWd/slug. Total activity is about 6x10¹¹Bq.

The reactor contains no radwastes. No radionuclides are discharged to the environment. The argon-41 release is negligible because of a low thermal neutron flux in the reactor.

The reactor has no RM and RW storages.

In case of the reactor putting out of service the 430 t of the reactor graphite stack are the only potential RW.

6.2.1.2. Reactor VVR-2

The reactor is decommissioned in 1983.

The spent fuel having been accumulated in the reactor from 1956-1982 is kept in the fuel pond: 2657 fuel rods (initial enrichment - 10%) and 1447 fuel rods (initial enrichment - 36%), the total weigh of fissile materials (FM) - 241.6 kg. The total activity of fission products in the spent fuel is about 2x10¹⁵ Bq.

The uranium activity - 5.2x10⁹ Bq.

There were no radionuclide discharges to the environment.

The argon-41 release to the environment did not exceed 0.5 Ci/h.

The reactor has a liquid RW storage: two metallic tanks with a capacity of 50 m³ each. They contain 14 m³ of low-active liquid RW of total activity 2.6x10¹⁰ Bq. The storage age is over 30 years.

For solid radwastes there are two deep steel tanks of total volume 87 m³ containing about 70t of high-active solid RW (components of the dismantled reactor).

The total high-active solid RW activity is 3.1x10¹¹ Bq.

6.2.1.3. Reactor RFT

The reactor has been stopped and put out of service in 1962.

The spent fuel of the reactor having been accumulated for the period of its operation in 1953-1958 is kept in the dray storage of the MR reactor (initial enrichment - 10%).

The total FM weight - 302.44 kg.

The total activity of fission products in the spent fuel is about 3x10¹⁵ Bq, uranium activity is about 5x10⁹ Bq.

There were no discharges of radionuclides to the environment.

The steel reactor vessel with the graphite stack remains in the reactor building. Potential RW in case of the reactor vessel dismantling are the steel vessel parts, graphite and a part of the concrete reactor well accommodated in the vessel. The quantity of RW and their activity can be determined after the project of these works is worked out.

6.2.1.4. Reactor MR

The reactor is shut down in 1993. The first phase of putting it out of operation has been completed: the fuel was discharged and, after its hold up in the storage pool, put into the MR dry storage. The development of the project of the works in the subsequent phases of putting the reactor out of service has been started.

The spent fuel having been accumulated in the reactor from 1986 to 1993 is kept in the dry storage of the MR reactor: 187 fuel assemblies (initial enrichment 90%). The total FM weight is 63.3 kg.

The total activity of fission products in the spent fuel is about 4.4x10¹⁶ Bq, the uranium activity is about 4.4x10⁹ Bq.

The number of spent loop assemblies in the storage is about 200. The fission product (FP) activity is about 5x10¹⁶ Bq.

The dry storage is located in an isolated room of a building near the reactor building. The storage has three sections.

Section 1 is intended for storage of fuel assemblies (FA) of the RFT reactor (rows 1-16) and pilot loop FA (rows 17-24). The total number of cells in Section 1 is 192. The spent FA of the RFT reactor are kept in the cells in aluminium sealed casks. The spent loop FA are put into the cells in special sealed stainless steel casks.

Section II serves for storing spent FA from the MR reactor, which are transferred there upon holdup in the storage pool in the reactor building. The total number of Section II cells is 216. In this section the MR FA can be put into two rows in height.

Section III is intended for storage of the IRT-3M-type FA in aluminium casks. There are 117 cells in this section. The sections are covered from the top with a 46 cm thick protective steel plate with charging openings provided with plugs.

The storage age is about 40 years.

There were no radionuclide releases to the environment.

The reactor has three metallic tanks of 30 m³ each for storage of low-active liquid RW. They contained 20 m³ of liquid wastes with the total activity of 7.4x10⁸ Bq. There is a 30 m³ metallic tank for medium-active liquid RW containing 20 m³ of wastes with the total activity 7.4x10¹⁰ Bq.

The storage age is about 40 years.

For storage of solid radwastes seven deep concrete compartments and a concrete storage with 127 cells are provided. They contain high-active solid RW with the total activity of about 10¹⁵ Bq.

There is a considerable number of spent loop channels in the storage pool. Some sections of these channels have a high specific activity.

The total amount of solid RW which can be formed in the process of putting the reactor and its 10 loop facilities out of service can only be estimated after the project of conducting these operations is worked out.

6.2.1.5. Reactor IRT

The reactor was stopped in 1979 and put out of service as it was replaced by the IR-8 reactor. The dismantled in-pool equipment (reactor vessel, ejector, sections of the horizontal experimental channels) was transferred to the MNPO "Radon" storage.

The spent fuel was passed for reprocessing to the PO "Mayak".

6.2.1.6. Reactor IR-8

There are 16 fuel assemblies (initial fuel enrichment 90%, the uranium content in each FA-0.294 kg of FM) in the core. The burnup averaged over the core volume is about 25%.

The total activity of fission products in the core, with the reactor in operation, is 5.7x10¹⁶ Bq, uranium activity - 2.6x10⁸ Bq.

The storage pool designed for storage of up to 120 spent FA contains 36 fuel assemblies having been discharged out of the reactor during 1989-1995.The total weight of uranium in FA is 5.79 kg of FM.

The total activity of fission products in 36 FA is 3x10¹⁵ Bq, the uranium activity - 3.9x10⁸ Bq.

The reactor has two underground steel tanks each of 50m³ for liquid RW storage. There are 20 m³ of low activity liquid RW with the total activity 7.4x10⁶ Bq.

The storage age is about 40 years.

There were no radionuclide releases to the environment.

The argon-41 release to the environment did not exceed 1 Ci/h.

The reactor has no storage for solid radwastes.

6.2.1.7. Reactor IIN-3M-"Gidra"

This is a homogeneous reactor. The core volume - 40 liters of aqueous solution of UO₂SO₄. It contains 3.44 kg of uranium enriched to 90%. The burnup is insignificant. The total activity is about 3x10⁸ Bq. There are no radionuclide releases to the environment.

Argon-41 does not practically release to the environment because of a low neutron flux and pulse mode of operation.

The reactor has neither fuel no radwaste storages.

6.2.1.8. Reactor GAMMA

The core has 69 FA each containing 0.56 kg FM with the initial enrichment higher than 20%. The average burnup in the FA is 70 kWd. The total fuel activity is about 1.4x10⁹ Bq.

The reactor is provided with a 10m3 metallic container for liquid radwastes, containing 5 m³ of low-active liquid RW. The total activity of the liquid wastes is 2.0x10⁵ Bq.

The storage age is 13 years.

No radionuclides are released to the environment.

The argon-41 release to the environment is insignificant.

There are no solid radwastes in the reactor.

6.2.1.9. Reactor "ArgusQuot;

The "Argus" is a homogeneous reactor. Its core contains 22 l of aqueous solution of UO₂SO₄. There is 1.71 kg of uranium of 90% enrichment. The burnup is insignificant. The total fuel activity is 1.2x10⁸ Bq. No radionuclides are released to the environment.

The argon-41 to the environment is insignificant because of a low level of the thermal neutron flux.

The reactor has neither fuel nor RW storages.

6.2.1.10. Reactor OR

The core has 375 fuel rods each containing 0.025 kg of uranium of 36% initial enrichment. The average burnup in the fuel rod is 200 kWd.

The total activity of fission products in the core, with the reactor in operation, is about 3x10¹⁶ Bq, the uranium activity is about 3.3x10⁸ Bq.

For storing RW produced in the reactor operation the VVR-2 reactor storages are used (see item 2.1.2).

No radionuclides are released to the environment.

The argon-41 release to the environment does not exceed about 0.05 Ci/h.

6.2.1.11. Reactor "Romashka"

The reactor is shutdown in 1966 and decommissioned.

The spent fuel of the reactor having been accumulated during the reactor operation from 1964 to 1966 (44.5 kg FM) is stored in a dry storage.

The total activity of the fission products in the spent fuel is 2.9x10¹², the uranium activity is 3.2x10⁹ Bq.

No radionuclides were released to the environment.

The argon-41 to the environment was insignificant.

6.2.1.12. Critical test facilities SF1, SF-3, SF-5, SF-7, "Kvant", physical model of the MR reactor, "Delta", UG, RBMK, V-1000, "ASTRA", "EFIR-2M", "Mayak", NARCISS-M2, GROG, P, ISKRA

The fuel used in the critical test facilities can be considered as practically "fresh" one since the power of most critical test facilities (CTF) does not exceed 100W, and the operation mode is continuous. Both the natural uranium and fuel enriched from 1.6% to 96% is used in CTF. The total quantity of fuel contained in all CTF is about 48270 kg. Its total activity is about 7x10¹¹ Bq.

No radionuclides were released from CTF to the environment.

There were no argon-41 release to the environment because of the low CTF power level.

At the RRC "Kurchatov Institute" critical test facilities there were no accidents in the reactors which could have resulted in the environment contamination, including the sanitary protection zone, with RW.

6.2.2. RF State Research center - Institute of Theoretical and Experimental Physics

6.2.2.1. Reactor TVR

The reactor was stopped in 1986 and is now in the decommissioning phase.

The spent fuel having been accumulated, for the period of the reactor operation from 1949 to 1986 was transferred to PO "Mayak".

No radionuclides were released to the environment.

In the reactor hall remains the heavy water moderator-coolant contaminated with tritium.

There is no liquid RW in the reactor.

Low active solid RW are stored in the concrete biological shielding of the reactor. Their mass is 995 t, volume- 414 m³, activity - 1.87x10¹⁰ Bq.

Medium-active solid RW are stored in the concrete biological shielding of the reactor. their mass is 84.14t, volume - 33.14 m³, activity 215x10¹⁰ Bq.

High-active solid RW are kept in a special shielded well.

Their mass is 1.1 t, activity 12.54x10¹⁰ Bq. The isotopes determining activity are Co-60, Cs-137.

Potential RW to be released in case of the reactor dismantling are parts of the steel vessel, heavy water and a part of the reactor well concrete.

The quantity of RW and their activity can be determined after the project of fulfillment of these operations is worked out.

6.2.2.2. Critical test facility "Mayak"

The core contains 300 FA (initial enrichment 90%). No burnup. The CTF has neither radwaste nor fuel storages.

No radionuclides were released to the environment.

No argon-41 releases were to the environment.

6.2.3. Moscow State Institute of Engineering Physics (Engineering University)

6.2.3.1. Reactor IRT

The core contains 15-16 FA (initial fuel enrichment - 90%, uranium content in the six-tube FA - 0.294 kg, in the eight-tube FA - 0.333 kg FM).

The uranium-235 burnup average over the core is about 20%.

The total activity of fission products in the core of the operating reactor is 2.5x10¹⁷ Bq, uranium activity is 3.6x10⁸ Bq.

The spent fuel having been discharged out of the reactor up to 1982 was transferred to PO "Mayak".

The spent fuel having been discharged out of the reactor in the period from 1982 to 1991 is stored in the reactor storage well representing an aluminium tank located near the reactor pool in the concrete shielding.

The total number of FA kept in the storage well is 52, total weight of uranium in FA is 19 kg of FM. The total activity of fission products in the fuel is 0.3x10¹⁷ Bq, the uranium activity is 7x10⁸ Bq.

The reactor is provided with two steel reservoirs each of 100 m³, which contain 30 m³ of low-active liquid RW. The total activity of liquid RW is 107 Bq.

The storage age is 30 years.

The low-active solid wastes are temporarily kept in paper and polyethylene bags.

No radionuclides were released to the environment.

The argon-41 release to the environment did not exceed 0.3 Ci/h.

For the whole period of the reactor operation there were no accidents with RW releases which could have contaminated the environment including the sanitary protection zone.

Potential RW to be released in case of the reactor dismantling are in-pool components of the reactor, a part of the biological shielding etc.

6.2.4. Research and Design institute of Power Engineering

6.2.4.1. Reactor IR-50

The reactor was shutdown for reconstruction in 1993.

The spent fuel having been accumulated in the reactor during its operation from 1961 to 1993 is stored in a wet storage tank: 603 FR (initial enrichment - 10%). The fuel burnup is about 1%.

The total activity of fission products in the spent fuel is 0.25x10¹⁵ Bq.

No liquid RW is in the reactor.

An insignificant amount of solid RW contained in the reactor is gradually transferred to MNPO "Radon".

No radionuclides were released to the environment.

The argon-41 release to the environment was insignificant.

During the reactor operation there were no accidents which could have result in the contamination of the environment, including the sanitary protection zone, with RW.

6.2.5. Research Institute of Instruments

6.2.5.1. Reactor IRV

The reactor was shutdown in 1990 for reconstruction.

The spent fuel having been accumulated in the reactor during its operation from 1974 to 1990 is kept in the reactor storage: 22 FA (initial enrichment - 90%, burnup 10.35 MWd/FA). The total uranium-235 weight in the spent FA - 3.46 kg. The total fission product activity in the fuel is 7.4x10¹² Bq.

The low-active liquid wastes are stored in sumps and tanks of the special water treating station. Their volume is 5 m³, activity - 1.8x10⁶ Bq.

The low-active solid wastes are stored on special shelves and in casks. Their weight is 0.165 t, volume - 1 m³, activity - 1.2x10⁷ Bq.

The medium-active solid RW are kept in special containers. Their weight is 30.76 t, volume - 40 m³, activity - 3x10¹² Bq.

There were no radionuclide releases to the environment.

The argon-41 to the environment was insignificant.

During the reactor operation there were no accidents which could have led to the RW contamination of the environment including the sanitary protection zone.

6.2.6. State Research Center RF Konstantinov Institute of Nuclear Physics

6.2.6.1. Reactor VVR-M

The core contains 145 FA (initial fuel enrichment - 90% uranium content per FA - 0.074 kg). The total activity of fission products in the core - 1.8x10¹⁸ Bq, uranium activity - 7x10⁸ Bq.

The spent fuel having been discharged out of the reactor by 1980 was transferred to PO "Mayak". The spent fuel having been discharged out of the reactor from 1980 to 1995 is kept in the storage pool located near the massive biological reactor shielding below the floor of the experimental hall. The total number of FA in the storage is 802. The total weight of uranium in FA is 43 kg. The total activity of fission products is 2x10¹⁷ Bq, uranium activity is 3x10⁹ Bq.

The reactor has two underground and a surface steel tanks of 300 m³ each. They contain 150 m³ low active liquid RW.

The total activity of liquid RW is 5.5x10⁹ Bq.

The storage age is about 36 years.

The reactor has no solid radwaste storage. The solid low-active RW are temporarily kept in bags and casks.

There are no radionuclide releases to the environment.

The argon-41 release to the environment did not exceed 2 Ci/h.

During the reactor operation there were no accidents which could have resulted in the RW contamination of the environment including the sanitary protection zone.

6.2.6.2. Critical test facility with the physical model of PI reactor

The core of the PI physical model contains 18 FA with 30.6 kg uranium enriched with uranium-235 to 90%. The total uranium activity is about 2x10⁹ Bq.

No radionuclides were released to the environment.

6.2.7. RF State Research Center-Research Institute of Atomic Reactors

6.2.7.1. Reactor SM-3

The core contains 28 FA (initial fuel enrichment - 90%, the uranium content in a full FA - 1.05 kg, in the FA for target irradiation the uranium content is 0.89 kg).

The total activity of fission products in the core is 16.8x10¹⁸ Bq.

Two interim repositories of spent FA are mounted in the reactor vessel. They can accommodate up to 16 FA without depressurizing the reactor. The system of temporary FA storage in the reactor involves three fuel ponds made of stainless steel. The fuel ponds of the storage can contain up 852 FA.

The storage age is about 35 years.

For collection and interim storage of liquid radwastes there is a 8 m³ stainless steel tanks and two carbon steel tanks, each of 3 m³.

For collection of solid RW of high specific activity a heavy box is used, slightly active solid wastes are collected in a container.

No radionuclides were released to the environment.

6.2.7.2. Reactor MIR-M1

The core contains 48 FA (initial fuel enrichment - 90%, uranium content in FA 0.39 kg). The total activity of fission products in the core is 6.8x10¹⁸ Bq.

The spent FA having been discharged out of the reactor in 1966-1996 are stored in the fuel pond made of stainless steel. The fuel pond can contain up to 356 FA and up to 22 experimental tubes.

The storage age is about 30 years.

No radionuclides are released to the environment.

6.2.7.3. Reactor BOR-60

There are 100 FA (initial fuel enrichment - 90%) in the core. The total activity of fission products in the core - 10.6x10¹⁸ Bq, uranium activity - 7.8x10⁸ Bq.

The spent FA having been discharged out of the reactor in the period from 1969 to 1996 are stored in the stainless steel fuel pond. The fuel pond is designed to contain up to 356 FA and up to 22 experimental tubes.

The storage age is about 28 years.

No radionuclides were released to the environment.

6.2.7.4. Reactor PBT-6

The core contains 56 spent FA of the SM-3 reactor (initial fuel enrichment - 63%). The total activity of fission products in the core 1.1x10¹⁸ Bq.

There is no spent fuel storage in the reactor as it uses the spent FA of the SM-3 reactor.

No radionuclides were released to the environments.

6.2.7.5. Reactor RBT-10/I

The core contains 78 spent FA of the SM-3 reactor (initial fuel enrichment - 63%). The total activity of fission products in the core - 1.8× 19¹⁸ Bq.

The reactor has no spent fuel storage as it uses the spent FA of the SM-3 reactor.

No radionuclides were released to the environment.

6.2.7.6. Reactor RBT-10/2

There are 78 FA (initial fuel enrichment - 63%) in the core. The total activity of fission products in the core - 1.8x10¹⁸ Bq.

The reactor has no spent fuel storage as it uses the spent FA of the SM-3 reactor.

No radionuclides were released to the environment.

6.2.7.7. Reactor BK-50

The core contains 72 FA (initial fuel enrichment 2; 2.4 and 3%). the total activity of FP in the cores is 35.2x10¹⁸ Bq.

Liquid radwastes are stored in a 50 m³ stainless steel tank.

6.2.7.8. Critical test facilities with the physical models of the SM-3 and MIR-M1 reactors

The fuel used in the critical test facilities (CTF) can be considered practically "fresh" as the power of most CTF does not exceed 100 W and they operate in the continuous mode. In the CTF the fuel of 90% enrichment is used. The total activity of the fuel is about 10¹¹ Bq.

No radionuclides were released to the environment.

No argon-41 was released to the environment because of a low CTF power.

The RF SRC NIIAR has a centralized system of storing spent FA as well as of collection, storage and disposal of liquid and solid RW from all the institute installations.

The spent FA storage consists of two 7 m deep pools containing 5200 FA with 85 t of uranium including 4t of uranium of 90% enrichment.

On the whole amount of wastes the shares of RAS from the reactors, radiochemical production and special laundry are 60%, 10% and 15%, respectively. Liquid low - and medium active RW are transferred by the special sewerage systems to a 200 m³ tank and four reservoirs each of 2000 m³. The total activity of these wastes is 1.5x10¹² Bq. The waste activity is determined by isotopes Cs-134, Cs-137, Sr-90, I-131, Ru-103, Ru-106, Co-60 etc. After averaging, settling and neutralization the low-active liquid RW are pumped into the underground repository of a semi-industrial test site which is a system of injection and observation wells provided with appropriate process equipment and systems of technical control and radiation monitoring. The activity of RW pumped into the ground repository is 4.1x10¹⁵ Bq.

The high-active liquid RW are transferred by the special sewerage system to seven reservoirs: three of 500 m³, two of 600 m³, two of 6000 m³ capacity. The total activity of these wastes is 9.3x10¹⁴ Bq, volume - 3300 m³. The activity of the wastes is determined by isotopes Cs-134 Cs-137, Sr-90, I-131, Ru-103, Ru-106, Co-60 etc.

The low-active solid RW in paper bags are transferred to trenches which, upon being filled up, are covered with a 1.5-2 m thick layer of soil. Around the bunker a system of wells is provided for controlling ground waters. The total activity of these, annually produced, wastes is 7.4x10¹¹ Bq.

The high-active solid RW are shipped by special vehicles to high active waste burials in reinforced concrete bunkers. The total activity of these wastes is 3.3x10¹⁶ Bq, volume - in excess of 1700 m³.

On the CTF and reactors of the RF SRC NIIAR no accidents occurred, which would have led to RW contamination of the environment including the sanitary protection zone.

6.2.8. Research Institute of Nuclear Physics of Tomsk Polytechnical University

6.2.8.1. Reactor IRT-T

The core contains 20 FA (initial fuel enrichment - 90%, uranium content in a six-tube FA - 0.294 kg, in an eight-tube FA - 0.333 kg).

The total activity of fission products in the core of the operating reactor is 6x10¹⁷ Bq. The uranium activity - 2.2x10⁸ Bq.

The spent fuel discharged out of the reactor is stored in a storage well. The total number of FA in the storage is 64, total weight of uranium - about 34 kg. The total activity of fission products - 6x10¹⁶ Bq, uranium activity - 9x10⁸ Bq.

The reactor is provided with steel tanks for liquid RW storage:

• two of 100 m³ each
• one of 325 m³.

The total quantity of low-active liquid RW contained in these tanks is: 100 m³, 25 m³ and 50 m³ in the first, second and third tanks, respectively.

The total activity of liquid RW is 3x10¹⁰ Bq, including Co-60 - 4.8x10⁸ Bq, Cs-134× 10⁸ Bq, Cs-137-3.8x10⁸ Bq.

The storage age is about 30 years.

The reactor has no solid RW storages.

No radionuclides are released to the environment.

The argon-41 release to the environment does not exceed 1 Ci/h.

During the reactor operation there were no accidents which could have resulted in the RW contamination of the environment including the sanitary protection zone.

6.2.9. Sverdlovsk Branch of Research and Design Institute of Power Engineering

6.2.9.1. Reactor IVV-2M

The core contains 42 FA (initial fuel enrichment - 90%, uranium content in a FA is 0.25 kg).

The total activity of fission products in the core of the operating reactor - 2.8x10¹⁸ Bq.

The spent fuel having been discharged out of the reactor by 1991 was transferred to PO "Mayak". The spent fuel having been discharged from the reactor from 1992 to 1996 is stored in a permanent storage pool.

The low active liquid RW are stored in special tanks of 100 m³ each. Their total activity is 4.4x10¹¹ Bq.

The low-level solid RW are stored in special containers on working places, their annual buildup is 35 m³.

The medium-active solid RW are kept in special containers on working places, their annual buildup is 15 m³.

The low- and medium-active solid RW are transferred for disposal to the special combine "Radon" (Pyshma) and high-active RW - to the PO "Mayak".

6.2.10 RF State Research Center "Institute of Physical and Power Engineering" (FEI)

The RF SRC set up in 1946 has two research reactors and a great number of critical assemblies. A large quantity of various RW had been accumulated.

6.2.10.1. Reactor AM

The core contains 122 FA including 31 FA with the initial enrichment 4.4% and 91 FA with the initial enrichment 10%. The FM content in the FA is 120 kg. The fuel burnup in the FA - 60 MWd/FA and 100 MWd/FA, respectively. The total fuel activity is 2x10 ¹⁸ Bq.

The spent fuel having been discharged out of the reactor for the period from 1962 to 1996 is stored in the fuel pond. The total number of FA in the fuel pond is 297. The total mass of FM in the fuel is 1250 kg.

In the centralized SNF storage of RF SPC FEI 4274 fuel rods of the reactor AM are stored, which had been discharged from 1962 to 1996 with a burnup of 25-35 MWd/FR.

The reactor has no liquid RW storage.

The total quantity of solid RW is 90t (30 m³), their activity is 5.55x10¹² Bq. They are stored in a 148 m³ concrete bunker.

No radionuclides are released to the environment.

6.2.10.2. Reactor BR-10

The core contains 97 FA (initial enrichment - 90%, total weight of FM - 130 kg). The fuel burnup in the core is 5500 MWd/t. The total activity of fission products is 1.6x10¹⁸ Bq.

The spent fuel having been discharged out of the reactor for the period from 1959 to 1991 is stored in the centralized SNF storage of RF SRC FEI.

The total number of FA in the storage is 497, the fuel burnup is 20-35 MWd/FA. The total quantity of FM in the FA is 0.93 t. The total activity of fission products is 3.7x10¹⁶ Bq.

The liquid RW are stored in a metallic reservoir. Their total volume is 14.6 m³, activity - 1.33x10¹³ Bq.

The high-active solid RW are stored in a concrete bunker. Their weight is 4.5 t, volume 0.9 m³. The total activity is 6x10¹³ Bq.

No radionuclides are released to the environment.

6.2.10.3. Critical test facilities BR-1, BFS-1, RF-GS, MATR-2, PS-2, T-2, SGO, "Strela", BFS-2, KOBR, AMBF-2, FS-1M, K-1

The fuel used in the CTF can be considered as practically "fresh", as the power of most CTF does not exceed 100 W, and they operate in a continuous mode. Both natural uranium and fuel of 1.6% to 96% enrichment are used in the CTF.

No radionuclides are released to the environment.

The total content of FM in spent FA of RF SRC FEI is 14.52t. The total activity of fission products is 4x10¹⁷ Bq.

6.2.11. Branch of RF State Research Center - Karpov Institute of Physical Chemistry

6.2.11.1. Reactor VVR-C

The core contains 70 FA (initial fuel enrichment is 36%, uranium content in a FA is 0.3-303 kg).

The total activity of fission products in the core of the operating reactor is 1.4x10¹⁸ Bq. The uranium activity is 6.5x10⁸Bq.

The spent fuel having been discharged out of the reactor by 1991 was transferred to PO "Mayak". The spent fuel having been discharged out of the reactor from 1991 to 1995 is kept in the storage pool: 242 FA, the total weight of uranium in the FA is about 63 kg. The total activity of fission products in them is 2x10¹⁷. The uranium activity is 1.8x10⁹ Bq.

The reactor has a 200 m³ stainless steel tank, for storing the low-active liquid RW where 14 m³ of wastes of the total activity 2.6x10¹⁰ Bq are stored. The storage age is about 31 year.

For storing medium-active liquid RW a 200 m³ stainless steel tank divided into two compartments is provided. It contains no wastes. The tank age is about 31 yr.

There are three storages for solid RW.

• a 150 m³ woodlined deep cavity in the concrete floor for low-active solid RW, where 60 m³ of wastes are contained;
• a 225 m³ reinforced concrete semi-deep cavity for high-active solid RW, where 70 m³ of wastes of total activity about 3x10¹¹ Bq are stored.

The storage age is about 31 yr.

No radionuclides were released to the environment.

The argon-41 release to the environment does not exceed 1.85x10¹⁰ Bq/h.

During the reactor operation no accidents occurred. The environment including the sanitary protection zone is not contaminated with RW.

6.2.12. Latvia AS Institute of Physics

6.2.12.1. Reactor IRT-M

The core contains 21 FA (initial enrichment - 90%, uranium content in FA - 0.294 kg and 0.333 kg in the six- and eight-tube FA, respectively).

The total activity of fission products in the core of the operating reactor - 5x10¹⁷ Bq. The uranium activity - 3.8x10⁸ Bq.

The spent fuel having been discharge out of the reactor by 1987 was transferred to PO "Mayak". The spent fuel having been discharged out of the reactor from 1987 to 1994 is stored in the storage well: 44 FA, the total weight of uranium in them is 8.8 kg.

The total activity of fission products in the FA is estimated as 2x10¹⁶ Bq, uranium activity is 6x10⁸ Bq.

The reactor is provided with two underground metallic tanks of 100 m³ each for storing liquid RW. There are no data available about the content of low-active liquid RW in these tanks.

The age of the storage is about 34 yr.

The reactor has no storage for solid RW.

No radionuclides were released to the environment.

The argon release to the environment does not exceed 1.85x10¹⁰ Bq/h.

During the reactor operation no accidents occurred.

The environment including the sanitary protection zone is not contaminated with RW.

6.2.13. Byelorus AS Institute of Nuclear Power

6.2.13.1. Reactor IRT-M

The reactor was shutdown in 1988 and put out of operation.

Practically all the spent fuel having been accumulated for all the operation time was transferred to PO "Mayak". In the reactor storage pool remained 24 EK-10 fuel rods (initial fuel enrichment - 10%, uranium-235 content in the fuel rod - 8 g), having been discharged in the 70s. The fuel burnup is 20%. The total activity of fission products in the fuel assemblies is estimated as about 10 Bq.

No radionuclides were released to the environment.

The argon-41 release to the environment did not exceed 1.85x10¹⁰ Bq/h.

During the reactor operation no accidents occurred. The environment including the sanitary protection zone are not contaminated with RW.

6.2.14. Ukrainian AS Institute of Nuclear Research

6.2.14.1. Reactor VVR-M

The core contains 140 FA (initial fuel enrichment - 36%, uranium content in an FA - 0.09 kg).

The total activity of fission products in the core of the operating reactor is 10¹⁸ Bq. The uranium activity is 3.9x10⁸ Bq.

The spent fuel having been discharged out of the reactor is kept in the storage pool: 562 FA with the total weight of uranium in them about 42.3 kg. The total activity of fission products in them is estimated as 10¹⁷ Bq, the uranium activity is 1.3x10⁹ Bq.

The reactor is provided with two metallic reservoirs each of 330 m³ for storing liquid RW. There no data available about the quantity of wastes in these reservoirs. The reservoirs age is about 35 years.

There are two lined concrete bunkers for storing solid RW: one for low-active solid RW, the other - for medium active solid RW. The age of the storages is about 35 years. There are no data available on the quantity and activity of the waste contained in the storages.

No radionuclides are released to the environment.

The argon-41 release to the environment does not exceed 5.55x10¹⁰ Bq/h.

During the reactor operation there were no accidents which could have resulted in the contamination of the environment, including the sanitary protection zone, with RW.

6.2.15. Georgian AS Institute of Physics

6.2.15.1. Reactor IRT-M

The reactor was shutdown in 1990 and is being put out of operation. Practically all the fuel that has been discharged from the reactor is transferred to PO "Mayak". In the reactor remain some spent FA of different types (EK-10, IRT-M, TTR) with the total content of uranium-235 equal to 900 g. The uranium burnup is from 3% to 18%. The total activity of fission product is estimated as 10¹⁴ Bq.

There is some "fresh" (not spent) FA of EK-10, TTR, IVV-2, IRT-21 types with the uranium-235 content of 4.23 kg (initial uranium enrichment 10% and 90%).

No radionuclides were released to the environment.

The environment including the sanitary protection zone are not contaminated with RW.

6.2.16. Uzbekistan AS Institute of Nuclear Physics

6.2.16.1. Reactor VVR-SM

The core contains 24 FA (initial fuel enrichment - 90%, uranium content in an FA - 0.294 kg).

The total activity of fission products in the core, with the reactor in operation, is 10¹⁸ Bq. The uranium activity is 4x10⁸ Bq.

The spent fuel having been discharged out of the reactor by 1989 was sent to IA "Mayak". the spent fuel having been discharged from 1989 to July of 1995 remains in the permanent storage-pool and in an additional wet storage constructed in the 80s. The age of the permanent storage is about 35 yr. In both storages were kept (as of July 1995) 143 FA with the total uranium weight of 24.2 kg. The total activity of fission products there is estimated as 10¹⁷ Bq, uranium activity - 1.6x10⁹ Bq.

The reactor has two steel underground tanks of 300 m³ each for the storage of liquid RW. They contain 200 m³ of low-active liquid RW whose total activity is 6x10¹⁰ Bq.

The low-active solid RW are stored in metallic casks, kraft paper or polyethylene bags. Their total weight is 0.5 t.

The medium-active solid RW are kept in the interim repository, their total weight is 0.1t.

The total activity of low-active and medium-active RW is estimated as 7x10¹⁰ Bq.

As they are built up, the solid wastes are transferred to the regional storage in the Republic.

No radionuclides were released to the environment.

The argon-41 release to the environment did not exceed 1 Ci/h.

During the reactor operation no accidents occurred.

The environment including the sanitary protection zone is not contaminated with RW.

6.2.17. Commercial Corporation "Foton"

6.2.17.1. Reactor IIN

The core contains 4.4 kg of uranium enriched to 90%. Due to the pulse mode of operation the quantity of fission products is insignificant. The total uranium activity is estimated as 3.2x10⁸ Bq.

No radionuclides were released to the environment. No accidents occurred. The environment is not contaminated with RW.

6.2.18. Alma-Ata Branch of Institute of Atomic Energy of Republic Kazakhstan National Nuclear Center

6.2.18.1. Reactor VVR-K

The reactor was partly shutdown in 1988 because of doubts in its seismic stability. After appropriate studies the possibility of its safe operation was proved.

At present preparation to resuming reactor operations is in progress.

The spent fuel having been discharged out of the reactor from 1974 to 1988 is kept in the storage pool: 332 FA with the total weight of uranium about 88 kg. The total activity of fission products in FA is about 2x10¹⁶ Bq. The uranium activity is 2.7x10⁹ Bq.

The reactor has two steel tanks of 50 m³ each for storing low-active liquid RW and two steel tanks of 100 m³ each for high-active liquid RW.

The age of the storage is 28 yr.

No radionuclides were released to the environment.

The argon-41 release to the environment is about 1 Ci/h. During the reactor operation no accidents occurred. The environment including the sanitary protection zone is not contaminated.

6.2.18.2. Critical test facility with the physical model of VVR-K

The core of the VVR-K physical model contains 59 FA with 17.9 kg of uranium of 36% enrichment.

The total uranium activity is about 6.5x10⁸ Bq.

No radionuclides were released to the environment.

No accidents occurred at the critical test facility.

6.2.19. Institute of Atomic Energy of Republic Kazakhstan National Nuclear Center

6.2.19.1. Reactor IGR

The core consists of 2800 graphite blocks impregnated with uranium of 90% enrichment. Each block contains 3g of uranium. The fuel burnup is insignificant: 2 kWd/block ( 0.1%). The total uranium activity is about 6x10⁸ Bq.

No radionuclides were released to the environment.

There were no accidents on the reactor, which could have result in the RW contamination of the environment including the sanitary protection zone.

6.2.19.2. Reactor IVG-1

The core contains 31 FA (initial fuel enrichment - 90%, each FA contains 0.143 kg of uranium).

The fuel burnup is insignificant: about 0.1%.

The total core uranium activity is 3.2x10⁸ Bq.

No radionuclides were released to the environment.

There were no accidents on the reactor which could have resulted in the RW contamination of the environment including the sanitary protection zone.

6.2.20. Concern "Norilsk Nikel"

6.2.20.1. Reactor RG-1M

The core contains 50 FA (initial fuel enrichment - 10%, each FA containing 0.56 kg of uranium).

The total activity of fission products in the core of the operating reactor is about 7x10¹⁵ Bq. the uranium activity - 5.3x10⁸ Bq.

No radionuclides were released to the environment.

The argon-41 release to the environment is insignificant (<0.01 Ci/h).

There were no accidents on the reactor.

The above data on the research reactors are sufficiently complete but they do not include a number of reactors used for special purposes. It should be pointed out that these reactors operate in the pulse mode and, therefore, they had little RW accumulated.

6.3. Completeness and availability of the data

The data presented are complete enough. They do not include, however, a number of research reactors, used for special purposes, in particular, reactors in the Federal Nuclear Centers - VNIIEF (the All-Russia Research In stitute for Experimental Physics) and VNIITF (the All-Russia Research Institute for Technical Physics). An important circumstance is that the above-mentioned reactors work in a pulse mde, that is why the nuclear fuel in these reactors is not reloaded, and its activity level is low. Because of the same reason the RW accumulation in the reactors is insignificant.

Data concerning certain research reactors are still classified. For some reactors the data are not complete because of lack of necessary measurements. In particular, data concerning isotopic composition of SNF, liquid and solid RW are quite insufficient.

There are no databases available on RW and radioactive materials, accumulated at research reactors in Russia, except the RADLEG database

6.4. Problems of RW ans SNF management at the research reactors and in research institutes

All enterprises and institutions, having research reactors in their structure, are engaged in the following lines of activities related to RW and SNF management:

• accumulation, conditioning and disposal of low and medium specific activity level liquid RW;
• accumulation and long term storage of medium and high specific activity level liquid RW;
• accumulation and disposal of solid RW;
• transportation and interim storage of SNF.

The scale of these activities are, naturally, essentially different depending on the research reactors’ power, duration of their operation, scope and subject of experimental research.

SNF from research reactors of the former USSR was regularly brought to the RT-1 reprocessing plant in the Industrial Association "Mayak". For the last several years the economic situation has worsened, and the spent fuel has not practically been taken out. Nevertheless, there is no alternative to removing of the SNF to "Mayak" hereafter. Certain problems are connected with removing of spent experimental fuel as well as of fuel elements failed in the course of operation. Technical problems of the fuel elements’removal can be fully solved, but presently it is not possible because of the lack of financial means.

Solid RW are sent for disposal in the special combine of "Radon", but the situation has worsened herein too, and for the last years the RW removal has reduced, although no alternative to this solution is foreseen.

Problems of research reactors’ RW and SNF management are the same as those of other enterprises sending their SNF to Mayak and their RW to Radon. Some amount of spent nuclear fuel and radioactive specimens of construction materials comes from nuclear power plants to research institutes for investigation, increasing so the mass of RW in the institutes.

6.5. Conclusion

Research reactors and critical test facilities, built in nuclear research centers, differ greatly by design, power level, fuel form and composition, construction materials, operation mode, but, on the whole, it should be noted that power level of the reactors is relatively low, and this determines comparatively small amount of RW, accumulated in the nuclear research centers.

Spent fuel unloaded from research reactors for their operation time is kept in cooling ponds. The total activity of fission products in spent fuel assemblies is about 1.2x10¹⁸ Bq.

Liquid RW of research reactors are stored in steel and concrete reservoirs, their total activity is about 10¹⁵ Bq. The wastes are mainly concentrated in the RF SRC NIIAR, where the most powerful research reactors of the former USSR are operated. In NIIAR low-level LRW after averaging, settling and neutralization are pumped into deep underground repository of a semi-industrial test site. The total activity of LRW injected into the underground repository is 4.1x10¹⁵ Bq.

Low-level solid RW are stored in metallic barrels, paper or polyethylene bags. Medium-level SRW are kept in interim storage facilities. The total activity of low- and medium-level SRW may be estimated as equal to 5.9x10¹² Bq.

High-level solid RW are transported by special vehicles to burial facilities of high-level RW - reinforced concrete bunkers. The total activity of high-level SRW is about 3.3x10¹⁶ Bq.

The type of RW is mainly concentrated in NIIAR.

Practically no radionuclides were released into the environment.

For all the time period of research reactors and CTF operation there were no accidents, resulted in radioactive contamination of the environment, including the sanitary & protective zone areas.

REFERENCES

6.1. The research reactors of NIIAR and their experimental capabilities, - NIIAR (the Research Institute of Atomic Reactors), Dimitrovgrad, 1993.

6.2. Reseach and development in reactor scientific centers, The RRC Kurchatov Institute, Moscow, 1993.

6.3. Annual reports of research institutes.