Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_50 ( silver INTEGER, gold VARCHAR, nation VARCHAR )

### Question ###
what is the highest amount of silver when gold is 0 for soviet union?

### Accurate SQL ###

SELECT MAX(silver) FROM table_name_50 WHERE gold = 0 AND nation = "soviet union"