Storage, retrieval, 20 year

A. The Twenty Year Retrieval Storage has allowed us to continue operating while alternate methods of disposal could be established. The twenty year retrieval concept will become one of three things in the not too distant future. 

TRU are those containing isotopes, like 241Am and 243Am, that follow uranium in the periodic table and whose half-lives are >20 years. If their level of activity was more than 100 nanocuries of alpha-emitters per gram of waste material (up from 10 nanocuries/g in 1982), the waste could be disposed of by shallow burial. Otherwise, the waste had to be placed in retrievable storage for eventual transfer to a permanent repository. TRUs generally have low levels of radioactivity, generate very little heat, and can be handled by ordinary means without remote control (Eisenbud 1987 Murray 1994). 

An alternative to permanent isolation of the spent nuclear fuel is monitored, retrievable storage. This method has an advantage since, if reprocessing to remove potentially useful materials such as plutonium becomes feasible, the wastes are still accessible. The argument for this plan is that the technologies and alternatives available to society a few hundred years... 

Mr. Pahissa-Campa observed that uranium resources are not as great as originally estimated. He emphasized the nuclear energy being essential for at least the coming 50 years and that one must not squander uranium reserves as it was done with petroleum. This means that the spent fuel should be considered not as a common waste but as potentially reusable material. Safe, reliable and retrievable storage should be the approach until a definitive decision is taken. 

PEL Pg pmol PHS PMR ppb ppm ppt REL RfD RTECS sec SCE SIC SIR SMR STEL STORET TLV TSCA TRI TRS TWA u.s. UF yr WHO wk permissible exposure limit picogram picomole Public Health Service proportionate mortality ratio parts per billion parts per million parts per trillion recommended exposure limit Reference Dose Registry of Toxic Effects of Chemical Substances second sister chromatid exchange Standard Industrial Classification Standardized incidence ratio standard mortality ratio short term exposure limit STORAGE and RETRIEVAL threshold limit value Toxic Substances Control Act Toxics Release Inventory total reduced sulfur time-weighted average United States uncertainty factor year World Health Organization week... 

Thus the consistent Canadian philosophy has been to store irradiated fuel retrievably until a decision on its ultimate disposition is necessary or desirable. Experience with the storage of CANDU fuel now extends over 15 years and has provided confidence that this type of fuel can be stored safely and economically for the order of five decades, using proven technology. 

For several years we have been involved in a wide-ranging project to develop methods for the representation and searching of the three-dimensional (3-D) protein structures in the Brookhaven Protein Data Bank [28, 29], Our work derives from the graph-theoretic methods that are used for the storage and retrieval of information pertaining to both two-dimensional (2-D) and 3-D small molecules [1, 58]. 

It may take years for a company to compile and submit a regulatory package of completed studies in support of an application. Thus, data storage and retrieval are important. All raw data, documentation, records, protocols, specimens, and final reports generated as a result of a study should be retained. Specimens obtained from mutagenicity tests, specimens of soil, water, and plants, and wet specimens of blood, urine, feces, and biologic fluids, need not be retained after QA verification.6-8... 

Calculations were made for the initial and final states of the waste, and also year by year to show the impact of radioactive decay. Modelling of any short-term increases in hazard potential arising from retrieval, immobilisation and store management operations is outside the scope of the RHP, which is intended to be a measure of progress towards passively safe storage rather than a continuous hazard monitor . The RHP is normally calculated either annually or upon work-stream completion. 

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