Can morality survive without religion?
Yes. Moral systems aren't dependent on religion and they never actually have been. Morality is dependent on the the existence of a systemic purpose. Basically, so long as a particular culture exists, morality will survive. Culture is a moral system that is necessary for reconciling the goals of individuals, and ensuring that most of them can reach whatever goal they may have. Religion is a common means of establishing a purpose for a particular culture. It's not necessary, it's just … common.
The ability to reasonably discern right from wrong and follow through with it, technically everyone has a morality of some sort, a unique world view and value system which will form the basis of how they decide what is right and wrong. Inevitably this will be shaped by many interconnected factors such as culture, parenting, life experiences, education, etc. Morality exists outside of religion, but religion needs morality to be effective. Morality is a standard, but religion is a mere belief system.
Technically, atheists do not define morality by themselves. No one does. Morality is a social, collective construct, not an individual one. They define it by aspects in their particular society, laws, and culture. The only difference between the morals of a theist and the morals of an atheist in the same culture is the atheists have removed the morals which apply directly to religious matters or God. The rest of the standards still remain virtually the same.
Morality is not necessarily ethical or according to conscience. Anything can be "moral." It is a system of "acceptable" behavior, not correct or right behavior. That would be ethics. Ethics and morality are often confused with one another. Morality deals with controlling behavior, whereas ethics deal with the reasons behind behavior.
When I say that morality is not necessary ethical, I'm speaking from an analytical standpoint. Ethically speaking, taking a life for any reason other than to immediately preserve your life or the life of others is wrong. It is also wrong to take a life if other options are available to you, even if it is to preserve one's life.
However, morally, this is not the case. In many cultures, putting criminals to death even after they have been caught, or executing prisoners of war is not considered moral. And eating cat / dog meat in some cultures is considered immoral. But it would be unethical according to the standards of objective reasoning that govern volition and behavior under ethics. Forcing individuals to comply with the wishes of the majority even where not necessary for the greater good is also considered a harm and usually unethical. However, not only is it perfectly moral, but an ingrained concept in many moral codes.