my_list = [[34, 23, 34], [17, 46, 47], [22, 14, 22], [28, 91, 19]]

print("The list is :")
print(my_list)

my_result = [element for element in my_list if len(set(element)) == len(element)]

print("The result is :")
print(my_result)

The list is :
[[34, 23, 34], [17, 46, 47], [22, 14, 22], [28, 91, 19]]
The result is :
[[17, 46, 47], [28, 91, 19]]