Add a Complex property to EF 6.1 Model to handle Null value

Experts,

I am using Database First to design a Model for access to a database.  In the Stored Procedure I have a field that allows NULL values.  I have created the Entity Data Model as a separate Project that I can access from several applications as needed with the proper references.  When I was mapping the Stored Procedures I can't figure out exactly how to code for a field that is allowed to be null in the table.  The EF identifies the field with an extra line in the Stored Field Mapper of "@ IsNull_Table_FullDescription:int".

Here is the table "tblSupportTables" list of properties:

Field                                      Type
Table_ID                               int
Table_DateAdded              DateTime
Table_DateModified         DateTime
Table_CodeSequence      Int32
Table_RecordStatus         String
Table_Name                      String
Table_Version                   String
Table_FriendlyName       String
Table_BriefDescription   String
Table_FullDescription     String

The field "Table_FullDescription" can be NULL.  So when I mapped fields the Update and Delete Mappings added a new field. "IsNull_Table_FillDescription", with "int" as the type.

I think I have to create a new complex property?  Is this correct?  In VB.NET how would I write the code for this property?  The examples I have seen don't clearly show me so that is why I need your advice.  Thanks!