Safety has to be based on evidence. Should probing the secrets of the universe create a global threat? Is it relevant to bring up Marie Curie in safety arguments for unkown or complicated physics? How about the past nuclear fission research?

Fast reactors are a good example of known physics guiding the research for the missing experimental data such as the Doppler Coefficient. SEFOR was built just to make the needed measurements to assure the inherent safety of a fast reactor core. Later, indeed, EBR-II confirmed the correctness of this inherent feature of the fast reactors. It was shutdown in 1994 after 30 years of successful operation.

We have come a long way in understanding the risk content of engineered or man-made systems. Ridiculing risk analysis is futile. Any danger that is possibly threatening human life and resources will have to be dealt with in a large project like the Large Hadron Collider (LHC). People have rightly asked: How much of a risk would there have to be before these scientists would say we can't do the experiments?

The LHC will produce head on collisions between two beams of particles, either protons or lead ions. About 800 million collisions per second will actually be at the highest energies observed under laboratory conditions. To understand the risks here, it is customary to ask these three questions. 1. What can go wrong with LHC? 2. How likely is that to happen at LHC? 3. What are the consequences?

Interested parties like us outside the project are able to read Review of the Safety of LHC Collisions

( which says: "Having reviewed the theoretical and experimental developments since the previous safety report was published, we confirm its findings. There is no basis for any concerns about the consequences of new particles or forms of matter that could possibly be produced by the LHC."

OK, but is this an independent risk assessment? No, it is not. Furthermore, the conclusions state: "We have considered all the proposed speculative scenarios for new particles and states of matter that currently raise safety issues. Since our methodology is based on empirical reasoning based on experimental observations, it would be applicable to other exotic phenomena that might raise concerns in the future."

Hence, here is an opportuniy to establish another first by CERN for the future of science: Give us the scenarios, the choices, the evidence, we then do an independent risk assessment of LHC.

This invitation is to Lyn Evans, the project manager. Oh, until we do this, just say "What's your evidence?" to anyone who claims safety.