Schema for DICE

 

The Database for the International Handbook of Evaluated Criticality Safety Benchmark Experiments (DICE) is a tool intended to make a more efficient use of the handbook described in the previous section. DICE has two objectives:

• Provide a summary description of each experimental configuration, where the main characteristics of the experiments are displayed in a uniform format.
• Allow users to search the handbook for experimental configurations that satisfy their desired input criteria.

 

To meet these objectives, a relational database is created from the ICSBEP database. Specific information from each evaluation in the handbook is extracted and stored in the ICSBEP database. The DICE database is then copied from the ICSBEP database for the purpose of providing summaries and satisfying search requests.

 

The table below summarizes the relationship between the 13 tables or entities in the ICSBEP database and the DICE database.  Column one lists the name of each table in the ICSBEP database. Column two provides a brief description of the table's content.  Column three lists the name of the corresponding DBTable object constructed in the DICE database.

 

 

 

Note that the table icbreviewer appears in the ICSBEP database, but no DBTableobject is generated. This table is only used internally by NEA for master database updates. For this reason, DICE does not construct an associated DBTablefor this table.  The table ICBISO contains a list of isotopes referenced by table ICBCOMPS.

 

Table ICBMOD_ISO gives the composition of moderators. Among all isotopes present in a given moderator, this table provides the most important contributors to the slowing-down process of neutrons. Generally, the lighter an isotope, the more efficient it is for neutron slowing-down. For example, the most important isotope for the moderator water (i.e. H₂O) is H.

 

Table ICBMOD_ISO is used to select the relevant isotopes in fuel compositions. This information is used in calculations of the moderator to fuel ratio and moderator to fissile ratio values. Currently these values are calculated prior to execution of DICE so the table is not used.

 

Relational databases are organized into tables or entities consisting of rows and columns. Each entity is in a separate table and the fields in the table describe the attributes of the entity.

 

Tables are connected to each other through unique fields. A field or combination of fields that uniquely identifies each record in a table is called a primary key. The primary key in table icbcases, shown in the figure below is field EVAL_ID. A relationship links two tables by a common field appearing in both tables. The field EVAL_ID appears in both table icbcasesand table icbevaluators. The key field in the related table icbevaluatorsis called a foreign key. The figure below illustrates a one-to-many relationship between tables icbcases and icbevaluators. One record in table icbcases or icbevals can be related to many records in table icbevaluators. In other words, each case in table icbcases, can have more than one associated evaluator from table icbevaluators.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table icbdics

 

Table icbdics, shown above, is the "dictionary" of the ICSBEP database. Field DESCR contains strings indexed by a sequence number in field DICKEY. All other tables store the DICKEY value as a key for accessing the associated string in field DESCR. The table below is an extract from table icbdics.

 

 

 

The field DICNAME is a string that allows grouping of entries into "dictionaries". Possible values for field DICNAME are given in the table below. These values for field DICNAME are also the names of fields in other tables. For example, facility , mat_pu, and mat_mixed are fields in table icbevals.