Resource Type

Month

6 Matching Results

Results open in a new window/tab.

Mars ascent propulsion on a minimum scale (open access)

Mars ascent propulsion on a minimum scale

A concept is presented for a single stage vehicle intended to lift a Mars sample to an orbital rendezvous. At 200 kg liftoff mass, it can potentially be delivered by a Mars Pathfinder size aeroshell. Based on launch vehicle design principles, propellants are pumped from thin-walled low pressure tanks into compact high pressure thrusters. Technical risk is reduced by using non-cryogenic propellants, and by driving piston pumps with heated helium.
Date: March 3, 1998
Creator: Whitehead, J.C. & Guernsey, C.S.
System: The UNT Digital Library
Status and use of the Rocky Flats Environmental Technology Site Pipe Overpack Container for TRU waste storage and shipments (open access)

Status and use of the Rocky Flats Environmental Technology Site Pipe Overpack Container for TRU waste storage and shipments

The Pipe Overpack Container was designed to optimize shipments of high plutonium content transuranic waste from Rocky Flats Environmental Technology Site (RFETS) to Waste Isolation Pilot Plant (WIPP). The container was approved for use in the TRUPACT-II shipping container by the Nuclear Regulatory Commission in February 1997. The container optimizes shipments to WIPP by increasing the TRUPACT-II criticality limit from 325 fissile grams equivalent (FGE) to 2,800 FGE and provides additional shielding for handling wastes with high americium-241 (Am-241) content. The container was subsequently evaluated and approved for storage of highly dispersible TRU wastes and residues at RFETS. Thermal evaluation of the container shows that the container will mitigate the impact of a worst case thermal event from reactive or potentially pyrophoric materials. These materials contain hazards postulated by the Defense Nuclear Facilities Safety Board for interim storage. Packaging these reactive or potentially pyrophoric residues in the container without stabilizing the materials is under consideration at RFETS. The design, testing, and evaluations used in the approvals, and the current status of the container usage, will be discussed.
Date: March 3, 1998
Creator: Thorp, Donald T.; Rivera, Michael A. & Geinitz, Richard R.
System: The UNT Digital Library
Cementation of residue ion exchange resins at Rocky Flats (open access)

Cementation of residue ion exchange resins at Rocky Flats

Ion exchange resins have been used to purify nitric acid solutions of plutonium at Rocky Flats since the 1950s. Spent ion exchange resins were retained for eventual recovery of residual plutonium, typically by incineration followed by the aqueous extraction of plutonium from the resultant ash. The elimination of incineration as a recovery process in the late 1980s and the absence of a suitable alternative process for plutonium recovery from resins led to a situation where spent ion exchange resins were simply placed into temporary storage. This report describes the method that Rocky Flats is currently using to stabilize residue ion exchange resins. The objective of the resin stabilization program is: (1) to ensure their safety during interim storage at the site, and (2) to prepare them for ultimate shipment to the Waste Isolation Pilot Plant (WIPP) in New Mexico. Included in the discussion is a description of the safety concerns associated with ion exchange resins, alternatives considered for their stabilization, the selection of the preferred treatment method, the means of implementing the preferred option, and the progress to date.
Date: March 3, 1998
Creator: Dustin, D.F.; Beckman, T.D. & Madore, C.M.
System: The UNT Digital Library
Packaging and transportation system for K-Basin spent fuel (open access)

Packaging and transportation system for K-Basin spent fuel

This paper describes the cask/transportation system that was designed, procured and delivered to the Hanford K-Basin site at Richland, Washington. The performance requirements and design of the various components -- cask, trailer with cask tie-down system, and the cask operation equipment for the load-out pit -- will be discussed. The presentation will include the details of the factory acceptance testing and its results. The performance requirements for the cask/transportation system was dictated by the constraints imposed by the large number of high priority shipments and the spent fuel pool environment, and the complex interface requirements with other equipment and facility designs. The results of the testing form the basis for the conclusion that the system satisfies the site performance requirements. The cask/transportation system design was driven by the existing facility constraints and the limitations imposed by the large number of shipments over a short two-year period. This system may be useful information for other DOE facilities that may be or will be in a similar situation.
Date: March 3, 1998
Creator: Kee, A. T.
System: The UNT Digital Library
The use of filtered bags to increase waste payload capacity (open access)

The use of filtered bags to increase waste payload capacity

For the past few years, the Department of Energy has favored the direct disposal of low plutonium content residue materials from Rocky Flats rather than engage in expensive and time consuming plutonium recovery operations. One impediment to direct disposal has been the wattage limit imposed by the Waste Isolation Pilot Plant on hydrogenous materials such as combustibles and sludges. The issue of concern is the radiolytic generation and accumulation of hydrogen and other explosive gases in waste containers. The wattage limits that existed through 1996 restricted the amount of plutonium bearing hydrogenous materials that could be packaged in a WIPP bound waste drum to only a fraction of the capacity of a drum. Typically, only about one kilogram of combustible residue could be packaged in a waste drum before the wattage limit was exceeded resulting in an excessively large number of drums to be procured, stored, shipped, and interred. The Rocky Flats Environmental Technology Site has initiated the use of filtered plastic bags (called bag-out bags) used to remove transuranic waste materials from glove box lines. The bags contain small, disk like HEPA filters which are effective in containing radioactively contaminated particulate material but allow for the diffusion of hydrogen …
Date: March 3, 1998
Creator: Dustin, Donald F.; Thorp, Donald T. & Rivera, Michael A.
System: The UNT Digital Library
Progress in stabilization of plutonium and residues since DNFSB recommendation 94-1 (open access)

Progress in stabilization of plutonium and residues since DNFSB recommendation 94-1

There are approximately 100 metric tons of residues at the Rocky Flats Environmental Technology Site containing approximately 3 metric tons of plutonium. The residues are byproducts of past plutonium operations incinerator ash; pyrochemical salts; graphite; sand, slag, and crucible; and miscellaneous forms of combustibles, glass, metal, and sludges. In September 1993, a report was released (Reference 1) which identified concerns with the chemical stability of the residues and with the integrity of packaging. In May 1997, the Defense Nuclear Facility Safety Board published recommendation 94-1 citing a concern for the residue stability and requiring that the possibly unstable residues be processed within 3 years and all others within 5 years. A risk categorization scheme was developed which assigned a numerical risk to each residue type based on the probability and consequence of occurrence of failures associated with the hazards identified. The residues were ranked for priority of stabilization actions. Urgent concerns were resolved. All residue drums were vented to eliminate the potential for hydrogen and other explosive gas accumulation. Leaded rubber gloves and ion exchange resins were washed to eliminate the explosion potential. An aggressive characterization program was implemented to search for any additional safety or environmental concerns and to …
Date: March 3, 1998
Creator: Ball, J.M. & Dustin, D.F.
System: The UNT Digital Library