Reactor and spent fuel

Relevant data about the reactor and its spent fuel are given below. 

Reactor type Swimming pool research reactor 

Major functions Radioisotope production, material irradiation, physics research 

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Includes cumulative amounts from power reactors and spent fuel. 

The solidified low level radioactive wastes for which ultimate disposal must be provided fall into two broad categories the uranium-containing wastes from milling and the front end of the fuel cycle, including enrichment and the radionuclides from the nuclear reactors and spent fuel operations, together with the radionuclides from applications in research, medicine, and other industries.42... 

As radiation sources y-ray emitters, such as Co or Cs, and electron accelerators are applied. Nuclear reactors and spent fuel elements have also been discussed as radiation sources. 

In the case of the WWER NPPs, the polar crane in the reactor building lacks adequate interlocks. Interlocking is required to prevent the simultaneous transport of heavy loads over the reactor and spent fuel pool and a decoupling of the crane forks and hooks. 

Established transport routes avoid unnecessary movement over reactor and spent fuel pool. 

Stage 2 works could begin once removal of fuel (from reactor and spent fuel pool) has been completed, and the spent fuel area has been decontaminated and cleared for use. Current plans are that Stage 2 activities would take approximately 6 years to complete. 

In the structural failure characterizations for the reactor and spent fuel pool Level 2 PSA modeling, NRC is relying on a combination of (i) past assessments, (ii) new calculations using three-dimensional finite element analysis in conjunction with statistical data for the failure strain of the liner materials, as well as models for tearing of the liner, and (iii) assessments using engineering criteria. Of particular interest here are the characterizations of containment severe-accident-induced failure and spent fuel pool seismic failure. 

Most of the wastes dumped was low- and intermediate-level, but spent fuel and reactors fi-om nuclear submarines introduce high-level wastes. Since the time of the dumping total inventory of radioactivity has reduced due to the natural decay of radionuclides. Some of calculations suggest that less than 130,000 curies remains in the reactors and spent fuel deposited in the Arctic [OTA, p. 49]. 

The increasing number of atomic reactors used for power generation has been questioned from several environmental points of view. A modern atomic plant, as shown in Fig. 28-3, appears to be relatively pollution free compared to the more familiar fossil fuel-fired plant, which emits carbon monoxide and carbon dioxide, oxides of nitrogen and sulfur, hydrocarbons, and fly ash. However, waste and spent-fuel disposal problems may offset the apparent advantages. These problems (along with steam generator leaks) caused the plant shown in Fig. 28-3 to close permanently in 199T. 

Table 1. Chemical compositions (ivr%) of low-pressured water reactor (LWR) spent fuel and uraninite from Oldo reactors 10. 16 and Cigar Luke...

Radioactive wastes of concern include wastes that result from operation of the nuclear fuel cycle (mining, fuel fabrication, reactor operation, spent fuel reprocessing, and waste storage), from nuclear weapons testing, and from medical and research activities. In recent years, the emphasis has been on predicting the behavior of disposed high-level wastes in deep geologic... 

We shall be interested in estimating the fuel-cycle performance of this reactor during a steady-state cycle, in which fresh fuel has a enrichment of 3.2 w/o and spent fuel has a enrichment of around 1.0 w/o and also contains around 0.6 w/o fissile plutonium. The reference design condition used to evaluate effective neutron cross sections and other reactor physics parameters during irradiation is taken to be 2.7 w/o This value, slightly hi er than the arithmetic mean of the fissile content of fuel at the begiiming and end of irradiation, is intended to reflect the hl er cross section of fissile plutonium compared with... 

The reactors made plutonium by bombarding special fuel rods containing uranium with neutrons. Once the maximum amount of plutonium was produced, workers removed tlie fuel rods (now called spent fuel ) from the reactor. The spent fuel rods were extremely radioactive, and the process for recovering the plutonium used only remote-corttrolled equipment. 

The elimination of on-site refueling directly attacks the two greatest proliferation risks of the traditional power reactor accessibility of materials and use of the facility for illicit purposes. Elimination of on-site refueling removes easy access to both fresh and spent fuel from the reactor site. Fissile material is found only inside the reactor, where it is protected by both limitations of physical access and a very intense inherent radiation barrier. The only period where fissile materials might be considered at risk is during transportation and set up, and during early operation where the fission product buildup is limited. Access to fissile materiids and use of the reactor for illicit irradiation is furdier complicated by the lack of physical features and infi astructure to open the reactor vessel. 

Even if the transportation difficulties could be overcome, the high level of radioactivity of the spent fuel makes reprocessing a hazardous operation. At present in the United States spent fuel elements are kept in storage at reactor sites. Spent fuel is reprocessed, however, in France, Russia, the United Kingdom, India, and Japan. 

All the fuel handling equipment of V-392 reactor plant (in-plant transport packing set for fresh and spent fuel, leak-tight bottles, bottles of defective assembly detection system) have the cells for fuel assemblies made of hexahedral tubes. This measure provides for improvement of nuclear safety under accident situations and also prevents mechanical damage of fuel assembly during its installation and withdrawal from the fuel handling equipment. 

The principle decision on the discontinuance of the reactor operation in 2003 has been accepted. Proceeding from it the process of the preparatory work and development of the particular decommissioning programs is beginning now. First of all these are the programs on the radioactive wastes and spent fuel management. 

In May 1993 the Russian Federation provided information to the IAEA about the high and low level radioactive waste dumped in the Arctic Seas ("White Book-93"). According to the "White Book-93" the total amount of radioactivity dumped in the Arctic Seas was more than 90 PBq. The items dumped included six nuclear submarine reactors containing spent fuel, spent fuel from an icebreaker reactor, ten reactors without fuel, and liquid and solid low level waste. The nuclear reactors and the fuel from the icebreaker reactor were dumped in the shallow bays of Novaya Zemlya and in the Kara Sea. 

In-service inspection of ET-RR-1 reactor vessels and spent fuel storage tank... 

Fuel reprocessing Fuel reprocessing is carried out to recover uranium and plutonium from spent fuel used in reactors. Most spent fuel from reactors is retained on-site in interim storage, pending decision on ultimate disposal or retrievable storage. Only about 5-10% of fuel is submitted to the reprocessing stage of the nuclear fuel cycle. The plants are operated in France, Japan, and the UK. 

This section deals with information about the reactor vessel, the core, control rods and control rod drive mechanism, vessel head and head mounted components. It discusses the systems and equipment employed to handle and store both firesh and spent fuel. It also covers information on the primary, secondary and tertiary circuit as applicable, including associated systems e.g. steam generators, pressurizer, reactor coolant pumps etc. 

Other auxiliary systems serve to cool and clean the water in the condensation pool in the containment wetwell and the water in the reactor service and spent fuel storage pools on top of the containment structure. 

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