- 産業: Government
- Number of terms: 11131
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A long, slender, zirconium metal tube containing pellets of fissionable material, which provide fuel for nuclear reactors. Fuel rods are assembled into bundles called fuel assemblies, which are loaded individually into the reactor core.
Industry:Energy
The processing of reactor fuel to separate the unused fissionable material from waste material. Reprocessing extracts isotopes from spent nuclear fuel so they can be used again as reactor fuel. Commercial reprocessing is not practiced in the U. S. , although it has been practiced in the past. However, the U. S. Department of Defense oversees reprocessing programs at DOE facilities such as in Hanford, WA, and Savannah River, SC. These wastes as well as those wastes at a formerly operating commercial reprocessing facility at West Valley, NY, are not regulated by the NRC.
Industry:Energy
A thimble-sized ceramic cylinder (approximately 3/8-inch in diameter and 5/8-inch in length), consisting of uranium (typically uranium oxide, UO<sub>2</sub>), which has been enriched to increase the concentration of uranium-235 (U-235) to fuel a nuclear reactor. Modern reactor cores in pressurized-water reactors (PWRs) and boiling-water reactors (BWRs) may contain up to 10 million pellets, stacked in the fuel rods that form fuel assemblies.
Industry:Energy
The series of steps involved in supplying fuel for nuclear power reactors include the following:
* Uranium recovery to extract (or mine) uranium ore, and concentrate (or mill) the ore to produce "yellowcake“
* Conversion of yellowcake into uranium hexafluoride (UF<sub>6</sub>)
* Enrichment to increase the concentration of uranium-235 (U-235) in UF<sub>6</sub>
* Deconversion to reduce the hazards associated with the depleted uranium hexafluoride (DUF6), or tailings produced in earlier stages of the fuel cycle
* Fuel fabrication to convert enriched UF<sub>6</sub> into fuel for nuclear reactors
* Interim storage of spent nuclear fuel Reprocessing of high-level waste to recover the fissionable material remaining in the spent fuel (currently not done in the United States)
* Final disposition (disposal) of high-level waste
The NRC regulates these processes, as well as the fabrication of mixed oxide nuclear fuel, which is a combination of uranium and plutonium oxides.
Industry:Energy
A structured group of fuel rods (long, slender, metal tubes containing pellets of fissionable material, which provide fuel for nuclear reactors). Depending on the design, each reactor vessel may have dozens of fuel assemblies (also known as fuel bundles), each of which may contain 200 or more fuel rods.
Industry:Energy
A Federal law that requires Federal agencies to provide, upon written request, access to records or information. Some material is exempt from FOIA, and FOIA does not apply to records that are maintained by State and local governments, or Federal contractors, grantees or private organizations or businesses.
Industry:Energy
Special nuclear material, in any combination, in a quantity of 5000 grams or more computed by the formula, grams = (grams contained U-235) + 2. 5 (grams U-233 + grams plutonium). This class of material is sometimes referred to as a Category I quantity of material.
Industry:Energy
An on-the-job training program, sponsored by the NRC for assignees from other countries, usually under bilateral information exchange arrangements with their respective regulatory organizations.
Industry:Energy
Inspections designed to evaluate and improve the effectiveness of a licensee's security force and ability to defend a nuclear power plant and other nuclear facilities against a design-basis threat. An essential part of the security program instituted by the NRC, a full force-on-force inspection spans 2 weeks and includes tabletop drills and multiple simulated combat exercises between a mock commando-type adversary force and the plant’s security force.
Industry:Energy
The shutdown of a generating unit, transmission line, or other facility for emergency reasons, or a condition in which the equipment is unavailable as a result of an unanticipated breakdown. An outage (whether full, partial, or attributable to a failed start) is considered “forced” if it could not reasonably be delayed beyond 48 hours from identification of the problem, if there had been a strong commercial desire to do so. In particular, the following problems may result in forced outages:
* Any failure of mechanical, fuel handling, or electrical equipment or controls within the generator’s ownership or direct responsibility (i.e., from the point the generator is responsible for the fuel through to the electrical connection point)
* A failure of a mine or fuel transport system dedicated to that power station with a resulting fuel shortage that cannot be economically managed
* Inadvertent or operator error
* Limitations caused by fuel quality
Forced outages do not include scheduled outages for inspection, maintenance, or refueling.
Industry:Energy
