This past Sunday marked the seventy-five anniversary of the day when the world’s first man-made self-sustainable chain reaction happened.
On Dec. 2, 1942, Nobel laureate and Italian physicist Enrico Fermi, and 48 scientists and students in his team succeed in activating the first-ever nuclear chain reaction in a human controlled facility, a reactor known as Chicago Pile 1.
Chicago Pile 1 the world's first nuclear reactor was designed by Fermi. It was a covert facility built underneath the University of Chicago's Stagg Field football stadium.
The reactor contained no mechanical parts or electric wires. Instead, it was built with 400 tons of graphite bricks, 6 tons of uranium metal and 45 tons of uranium oxide sphere that shaped baseball. A famous quote by Fermi, the Chicago Pile 1 was “a crude pile of black bricks and wooden timber.
In the 20 minutes of its first self-sustainable chain reaction, the reactor managed to generate whopping half a watt of power, just enough to power an Edison bulb. Yet, the success of this "blockbuster" experiment marked the official beginning of the Atomic Age of human society.
Seventy-five years after Chicago Pile 1, many consider the advent of nuclear technology have changed the world for the better, many others would disagree.
For those who see the Atomic Age as the beginning of the end, history was marked with horrifying destructions and tormenting tensions. The Manhattan Project, inspired by Fermi’s success, built the mighty and terrifying weapon that the world ever saw. Arm race based on nuclear weapons changed the dynamics of international relations for generations. And human errors and natural disasters struck hard at the concept of nuclear power generation, casting doubt on the future of atomic energy.
Painful memories can be overwhelming, but the Atomic Age isn’t all doom and gloom. The peaceful and progressive side of atomic energy should not be overshadowed.
The use of nuclear energy has kept a colossal amount of fossil fuels from being consumed and contributes to the avoidance of greenhouse gas release. In 2011 the world's nuclear power plants supplied 2518 TWh (billion kWh) of electricity. Generating the same amount of electricity by coal, oil or natural gas could have dumped 1,200 to 2,200 million tonnes of carbon dioxide into the atmosphere.
It is an absolute fact that traditional nuclear power plants, still the major workhorses nowadays, pose safety and environmental hazard. The new generation of nuclear reactors has learned their lesson, and they are sprouting around the globe. Designs like fast neutron reactors and molten salt reactors, which have the passive fail-safe mechanism, minimum weaponizing potential, and produce minimum shorter-lives waste, are considered the future of nuclear technology.
Nuclear medicine, a discipline born before the atomic age, has benefited substantially from the emergence of medical isotopes. These radioactive substance are used primarily to diagnose illness. Take technetium-99 for example, this reactor-produced gamma ray emitting isotope constitutes over 80 percent of all radiology diagnostic scans around the world at the peak of its supply. The use of radionuclides in nuclear medicine helps advancing medical knowledge and treating thousands of millions of patients.
Radiation therapy, which uses high-energy radiation to shrink or kill tumors, is another example of how atomic energy can save lives. The radiation may be delivered by a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy, also called brachytherapy).
Radiation blasting seeds and plants can scramble DNA and produce random mutations of crops. Before specific gene editing tools like CRISPR came along, the irradiation technique represented a fast, cheap and straightforward to create genetic diversity for further selection of useful phenotypes. The widespread application of this method in developing countries has yielded over 3,000 economically valuable mutants. In Bangladesh, for example, varieties of rice produced via mutation breeding have increased crop yields threefold over the past few decades.
The Sterile Insect Technique (SIT) is a nuclear technique used to prevent and cope with medical and agricultural pandemics that are usually spread by flying insects. Male insects are sterilized with heavy doses of gamma rays or X-rays and released back into the wild. Although the irradiated entities are still sexually competitive, they cannot produce offspring. SIT has successfully controlled populations of mosquitoes, moths, tsetse flies, screwworms, and other pests. Recently, the SIT technique was used to combat the spread of the Zika virus in Brazil.
Sterilization technologies play a crucial role in keeping us healthy. For materials that susceptible to damage by chemical agents or heat, such as disposable medical equipment and perishable food items that may contain pathogens, gamma radiation represents an important option for sterilization. It is often operated in an enclosed facility with heavy shielding, and the radiation is emitted by a radioisotope that has high-level photon energies, which can thorough eliminate worms, bacteria or virus inside or on the surface of the treated materials.
In the end, the unlocking of atomic power, like many era-defining moments before it, did not eliminate our problems. But it did provide us a much more powerful tool to construct a better and live a healthy life. The opposite is also true: we now hold a far deadlier weapon to threaten or destroy each other.
The only way to continue the push for the peaceful and environmentally sustainable use of nuclear technology is to remember both the destruction and progress that happened the last 75 years of Atomic Age.
The World's First Human-Made Nuclear Reactor. Credit: SciShow