Tag: science

REFRESH — Astounding and (Perhaps) Little Known Facts about the NRC and Radioactive Materials

Brenda Akstulewicz
Regulatory Information Conference Assistant

refresh leafNuclear and radiation-related trivia is anything but trivial. It can be unexpectedly interesting – and you may find some of it surprising. This is a REFRESH of some little known “factoids” compiled from folks throughout the NRC.

* In the 1930s, a failed experiment by a Swiss physicist for detecting gas using a radioactive source led to the discovery of smoke detectors when the scientist lit a cigarette and the detector registered a reaction. The NRC approved 70 different smoke detector designs in 2012.

* It is estimated if only one NRC technical reviewer did each design certification application review, it would take 32 years to complete the review.

astronaut2* Some lightning rods contain Radium-226 to make them more effective.

* The NRC’s first Chairman, Bill Anders, was an astronaut on Apollo 8’s mission to the moon.

* NRC Inspectors from Region IV get a lot of frequent flier miles. They review activities in remote locations such as Guam, Saipan and the northern reaches of Alaska, among other locations.

* The NRC was the first federal agency to give the public electronic access to all of its public documents through the groundbreaking system known as ADAMS (Agencywide Documents Access and Management System).

* The final safety evaluation report for the ESBWR design certification document contains about 3,800 pages.

vet* The fastest growing use of nuclear materials in medicine is for diagnostic and cancer treatment procedures in veterinary medicine.

* The indicator lights in early appliances ─ such as clothes washers and dryers, coffeemakers, and stereos ─ used Krypton–85, a radioactive isotope.

* The NRC performs classified reviews of new Naval Reactor submarine and aircraft carrier reactor plants and provides advice to the Navy on the designs. This practice was initiated by President Kennedy in the 1960s.

* Three women have held the title of Chairman — Allison Macfarlane, Shirley Jackson and Greta Dicus.

* In 1992 Hurricane Andrew struck the Turkey Point nuclear power plant in Southern Florida, which prompted the NRC and FEMA to enter into a “Memorandum of Understanding” regarding emergency preparedness.

checklist* NRC’s longest serving commissioner was Commissioner Edward McGaffigan. He served 11 years (from 1996-2007) after appointments twice by President Clinton and once by President Bush. He died while still serving on the Commission.

* On average, NRC expends 6,160 hours of inspection effort at each operating reactor site each year.

This post originally ran in Summer 2013.

NRC Science 101: Understanding Ionizing Radiation – It’s Not That Bohr-ing!

Harry Anagnostopoulos
Health Physicist
 

science_101_squeakychalkIn this post, we will be discussing ionizing radiation. But to do that, we first have to talk about radiation, in general, and then build up to the concept of ionization.

In previous NRC Science 101 posts, we’ve talked about the composition of an atom, including electrons, protons and neutrons. In 1913, physicist Niels Bohr made adjustments to an earlier model which imagined that the structure of an atom was similar to a solar system: electrons in circular orbits around a “sun” otherwise known as an atomic nucleus.

While modern atomic science has a more accurate understanding of the atom, Bohr’s model is still useful. It is easy to visualize and helps us to think about the relationship between electrons and energy. So, for the purposes of this post, let’s use Bohr’s atomic model.

Radiation is simply the transfer of energy through a medium. The medium can be anything: water, air or even the vacuum of outer-space. The transfer of energy can be carried out by particles or by electromagnetic waves.

Let’s conduct a small experiment. Imagine putting your face close to (but not touching) a bare 100-watt light bulb in a lamp. If you did this, and closed your eyes, could you still tell if the light was on? Could you feel the heat on your face, even though you are not touching the bulb?

Of course you could. That’s radiation! Light, heat, pressure waves in the air (sound), radio signals, and x-rays are all forms of radiation.

atom2As noted in prior NRC Science 101 posts, the core of an atom (the nucleus) is surrounded by orbiting electrons, like planets or comets around a sun. The number of electrons (each with one negative electric charge) usually equals the number of positive charges in the center (from an equal number of protons). These charges cancel out. However, if an orbiting electron is pushed out of its orbit (due to it absorbing energy from an outside source), the charges are now unequal.

The result? An “ion pair” has been formed. The creation of an “ion pair” is called . . . ionization.

Ionizing radiation is radiation with enough energy to create ion pairs in atoms. It is ionizing radiation that is of particular interest to the NRC because of its potential to cause health effects (as will be discussed in a future post).

cometearthTo help you visualize this, think again about Bohr’s model. Imagine a comet (standing in place of an electron) passing through our solar system. As the comet approaches the sun, it feels an intensifying push as light from the sun imparts more and more energy to the comet. Eventually, there is so much “push” that the comet either changes speed or changes direction. Now where will it go? Will it now be on course to strike a planet or will it veer out of our solar system? It’s exactly what could happen to an electron in the subatomic universe it occupies.

But this example is nothing compared to the bizarre realm of atomic physics where a solar system (an atom) might spit out a mini-version of itself, split into two, or where two twin comets (electrons) might appear out of nothing! And there’s more! However, you will have to wait until a later post.