Outside drain - how to replace this grate?
i don't know what the numbers mean but if you get a measurement of the opening and bring that to a metal fabrication shop they may be able to fabricate a screen for you. This would result in a small raised edge, but would eliminate the need to jackhammer the concrete. I don't know what area you live in but i know that most areas have some place like this by just doing a quick search on the internet