Monthly Archives: March 2011

What is criticality?

The words “criticality” and “re-criticality” have been used extensively in the media coverage.  Criticality is a nuclear term that refers to the balance of neutrons in the system. “Subcritical” refers to a system where the loss rate of neutrons is … Continue reading

Posted in Basics

Plutonium in the Environment

Much recent news and many questions directed at the blog have centered around the detection of plutonium in soil and water surrounding the Fukushima reactors. This post will outline our current knowledge of the situation, as well as potential impacts … Continue reading

Posted in Radiation Protection

News update, 3/18

News Brief, 3/18/11, 10 AM EDT Spraying of spent fuel pools at Units 3 and 4 is still underway. Visual inspection of Unit 4’s pool showed water in the pool, and so efforts have been temporarily focused upon Unit 3. … Continue reading

Posted in Uncategorized

What is an isotope?

It seems that there is a lot of confusion as to what isotopes, radioisotopes, nuclides, and radionuclides are.  First, we have to go back to chemistry class and remember the periodic table of elements, which lists all of the chemical … Continue reading

Posted in Basics

On worst case scenarios

On prediction of “worst case” scenarios The blog has received a great number of questions surrounding worst case scenarios. This is not surprising given that such scenarios, with varying degrees of scientific merit, have been advanced in the media. The … Continue reading

Posted in Incident History

Progress Update at Fukushima Daiichi – 3/17/11 (3:30 pm EST)

The high levels of radiation braved by workers at the scene in Fukushima Daiichi appear to have reduced after the expansion of the workforce and announcements of infrastructure improvements to come. In recent days emergency managers were faced with an … Continue reading

Posted in Fukushima

A Summary on Plutonium in Nuclear Fuel

Mixed Oxide (MOX) Fuel Uranium occurs naturally on earth. We mine it, refine it, and use it as fuel in nuclear reactors. All other elements that can sustain the nuclear fission chain reaction, including plutonium, do not occur naturally on … Continue reading

Posted in Basics | 1 Comment