Symbol which demonstrates the danger of the nuclear waste

Hello Designers! I need someone who can draw a nice symbol / warning sign to show the danger of the nuclear waste. The symbol must be universal and everlasting (I mean for example after 10 000 years it will be understandable too) The reason: the nuclear waste must be stored at least 10 000 years, so after that time the symbol must be actual too and must be good warning sign for the people. I need the selected provider to explain me his/her idea: why he/she think the symbol is everlasting and useful. I need the symbol provided in PDF. Lowest bid and the best idea will win:) Thanks in advance, Esther