Limited quantity, radioactive material

The radioactive material storage limitation for radioactive material storage areas was used to develop the source term for an airborne release. Each radioactive material storage area may store radioactive material in excess of the HC3 threshold but less than the HC2 threshold of DOE-STD-1027-92, Change 1 (DOE, 1992). Therefore, HC2 quantities of radioactive material are the most that must be considered for a fire DBA source term. Thus, the HC2 quantities of radioactive material were used as a conservative bound to the source term. The actual inventory and isotope mix of radioactive material in a radioactive material storage area will change from time to time as new material is stored and old material is removed. 

Limited quantities of materials are defined in 49 CFR 173.403 and discussed in 49 CFR 173.425. The table in that section provides detailed guidance on what defines a limited quantity for solids in normal and special form, for tritiated liquids, and for gases. For example, a limited quantity normal form solid is a quantity of <10 A2 in total activity per package. The table also contains provisions for shipping instruments or articles containing small amounts of radioactivity as a limited quantity. 

RADIOACTIVE MATERIAL, EXCEPTED PACKAGE -LIMITED QUANTITY OF MATERIAL ... 

The separation of small amounts of radioactive material by the use of ion exchange resins is one of the most useful and flexible of separation methods, and one which can be readily adapted to remote control when large amounts of radioactive material are to be handled. The limit of the quantity will be reached when the resin decomposes under the action... 

The dose of radiation delivered by an internally deposited radionuclide depends on the quantity of radioactive material residing in situ. This quantity decreases as a function of the physical half-life of the radionuclide and the rate at which the element is redistributed or excreted (i.e., its biological half-life). Because the physical half-life is known precisely and the biological half-life can be characterized within limits for most radionuclides, the dose to a tissue that will ultimately be delivered by a given concentration of a radionuclide deposited therein can be predicted to a first approximation. The collective dose to a population that will be delivered by the radionuclide—the so-called collective dose commitment—serves as the basis for assessing the relevant long-term health effects of the nuclide. 

In 1934, nuclear physics was young and the neutron had only just been discovered, yet the transuranium project was approached with a remarkable degree of confidence. The concepts from chemistry and nuclear physics that framed and guided the investigation were never seriously questioned, even though the synthesis and identification of new elements was, by definition, a leap into the unknown. Similarly, researchers were relatively unconcerned about the limitations of their small-scale experiments, even though the experiments themselves were notoriously difficult due to the tiny quantities of radioactive material. 

Studies of the coordination chemistry of the actinides have been limited by a number of factors - the care needed in handling radioactive materials and the possibility of damage to human tissue from the radiation toxicity (especially Pu) the very small quantities available and very short half-lives of the later actinides radiation and heating damage to solutions and radiation damage (defects and dislocations) to crystals. 

The SITP is a quantity derived from the Annual Limit on Intake (ALI), an internationally accepted concept that has been acknowledged by the Government s Radioactive Waste Management Committee (RWMAC) as a valid method of establishing equivalent hazards of different waste types. The ALI is a derived limit for the permissible amount of radioactive material taken into the body of an adult radiation worker by inhalation or ingestion in a year. The ALI is the smaller value of intake of a given radionuclide in a year by the reference man that would result in either a committed effective dose equivalent of 0.05 Sv or 0.5 Sv to any individual organ or tissue. 

Elucidate the criteria for shipping limited quantity of radioactive material. 

Table 13.1 is merely a guide. Each laboratory should develop specific quantity limits. In some cases, the license under which the laboratory operates will specify the quantity limits. For instance, the NRC issues specific radioactive material licenses to facilities, and each license specifies the maximum quantity limit for a given radionuclide. At government owned and operated sites, the DOE facilities do... 

The material is a limited quantity packaged under authorized exceptions (excluding Class 7 (radioactive) material) or is a Packing Group III material in Class or Division 3, 4, 5, 6.1, 8, or 9 ... 

Only individuals likely to receive within 1 year more than 10% of the allowable dose limits are required to be monitored by the licensee. However, unless the dose is monitored, it is difficult to establish with certainty that an active user of radioisotopes may not have exceeded the 10% limit. Many licensees do monitor most users of radioactive materials by providing personnel dosimeters to measure external exposures, excluding those who only work with weak beta emitters. In order to monitor internal exposures, the licensee can perform measurements of (1) concentrations of radioactive materials in the air in the workplace, (2) quantities of radionuclides in the body, (3) quantities of radionuclides excreted from the body, or (4) combinations of these measurements. 

TA-V installations that could potentially affect or be affected by the HCF include the Annular Core Research Reactor (ACRR), Gamma Irradiation Facility (GIF), Auxiliary Hot Cell Facility (AHCF), Radiation Metrology Laboratory (RML), and the Sandia Pulse Reactor III (SPR III). The GIF provides two cobalt cells for total dose irradiation environments. A new GIF is under construction in the northeast quadrant of TA-V. SPR III provides intense neutron bursts for effects testing of materials and electronics. The RML provides radiation measurement services to Sandia s reactors, isotopic sources, and accelerator facilities. The AHCF provides a capability to handle limited quantities of radioactive material in a shielded cell. These facilities have separate SARs that describe potential accidents. The most severe accidents for all of these facilities involve the release of radiological materials which could necessitate a site evacuation. No physical damage to the HCF could be induced by any of the postulated accidents, nor could any of the HCF accidents physically affect any of the other facilities. 

Hoods and shielded gloveboxes are used In Rooms 113 and 113A to accomplish isotope production quality control that consists of simple chemical processing steps and other light laboratory operations with limited quantities of radioactive materials. The shielded glovebox Is exhausted through HEPA filters by fans 15 or 16, while the hoods are exhausted through a HEPA filter by fan 17. 

This internally initiated DBA is a potential fire in a radioactive material storage area that is associated with the HCF. Limited quantities of combustible material are present in some of the radioactive material storage areas. Additionally, ignition sources, primarily electrical, also exist and are active in some of the radioactive materiai storage areas. Thus, the potential exists for a fire in some of the radioactive materiai storage areas. 

The labeling requirements for radioactive material are set forth in 49 CFR 172.403. There are, however, many exceptions to labeling requirements in the specific provisions for limited quantity shipments, LSA, and SCO, as discussed in 49 CFR 173.421 through 173.427, and the requirements of these sections should always be reviewed first before considering the standard labeling requirements. 

Developing a DSA requires that an inventory of potential hazards within the facility be developed. One method of identifying potential hazards is to use a checklist. Normally, a team comprised of engineering, operations, and safety would do a wall down of the facility. Many sites have an inventory system that identifies chemicals and their quantities. This inventory system should be queried to determine what chemicals are in the facility. Radioactive material inventory and sealed source inventory systems should also be used to determine their inventories. A typical hazard identification checklist is provided in Table 20.3. Dispositions are either identified as a Standard Industrial Hazard, screened out due to limited quantities of hazardous material, or are carried forth as an initiator of an event or the hazard from an event. The criteria identified in Table 20.4 are used to determine which hazards require further review. 

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