Description¶

The element library allows the user to define the isotopic abundances to be used for each element. While this library should normally include a definition of the natural abundances for each element, an extension is available for defining enriched or isotopically tailored elements.

Format¶

An element library can contain an arbitrary number of elemental definitions, each represented by a block with the following format. Every block must start with the following five entries:

• a string indicating the name/identifier,
• a floating point value for the molar mass,
• an integer value for the atomic number,
• a floating point value for the theoretical density, and
• an integer value defining the number of isotopes.

This is followed by two entries for each of these isotopes:

• an integer value for the mass number, and
• a floating point value for the atomic abundance, in %.

Example¶

Naming Elemental Definitions¶

The names/identifiers for all elemental definitions must be derived from the chemical symbol for that element, using the format ZZ[:AAA…], where ZZ represents the chemical symbol, and [:AAA…] represents an optional modifier, separated by a colon, ‘:’, from the chemical symbol. By convention, entries without modifiers are used to define the natural abundances of isotopes. The modifier must be a character string containing no whitespace. [example: a definition for lithium enriched to 90% in the isotope 6Li, might have the name ‘Li:90’.] These names/identifiers can be used both in a mixture block of the input file (when defining a constituent of type element) and in the material library.

Description¶

The material library is a mechanism for allowing users to save and re-use the definitons of a set of materials. Users are encouraged to develop their own material libraries, by adding material definitions to them as needed. Material libraries are all defined as lists of elemental definitions, each of which must occur in the Element Library.

Format¶

A material library can contain an arbitrary number of material definitions, each represented by a block with the following format. Every block must start with the following three entries:

• a string indicating the name/identifier,
• a floating point value for the theoretical density, and
• an integer defining the number of elemental definitions.

This is followed by three entries for each elemental definition:

• a string indicating the name/identifier,
• a floating point value for the weight fraction in %, and
• an integer for the atomic number.

Example¶

Naming Material Definitions¶

The name of a material definition must be a character string with no whitespace. The recommended practice is that material definitions never be deleted from a material library, ensuring the repeatability of results. It is expected, however, that many materials will undergo variations in their definition over time. It is therefore recommended that each material be named with a very specific identifier, perhaps containing dates, references, or project names. This will allow a single material library to be a growing and complete record of the material definitions used over time.

Description¶

Waste disposal ratings and clearance indices are used to provide a single metric for classifying the level of control required when disposing of used material. Each metric is based on a (possibly) unique list of isotopes and the allowable specific activities for those isotopes.

Format¶

The WDR/CI files contain the disposal limit expressed as either a volumetric or specific activity. These files are simple text files containing one pair for each isotope for which a limit exists. The first entry of each pair identifies the isotope using either the standard chemical symbol notation CC-AAAM (CC is the chemical symbol, AAA is the mass number, and M is the isomeric state: ‘m’ for the first isomeric state, ‘n’ for the second, and so on), or ALARA’s kza notation ZZAAAM (ZZ is the atomic number, AAA is the mass number, and M is the numerical isomeric state: ‘1’ for the first state, ‘2’ for the second, etc). The second entry is a specific activity in any combination of units supported by ALARA. The user is responsible for ensuring that the units chose in the output block match the units in the waste disposal limit file(s) used in that same block.

Example¶

Description¶

Because the reaction schemes/chains are created by a depth first search using the data from the transmutation and decay libraries, these libraries need to be accessed extensively and randomly. In the past, such random access was not possible due to limits on mass storage devices. Currently, in a text format, such random access would still be very tedious. To ensure that this random access does not create a drag on ALARA, it is necessary to either store the entire library in memory or use a binary file format. Because the libraries are often quite large (many MB) a simple binary format was designed.

Note¶

For more information, see the section on binary reaction libraries in the Developers’ Guide.