Posts Tagged ‘Japan nuclear power plant’

50 Mile Evacuation of Japan Nuclear Plant: Making Sense of Evacuation Distances

Monday, March 21st, 2011

Author: Jack Long, Director of CBRNE Preparedness, IEM

Since the US Nuclear Regulatory Commission recommended on March 16 that US residents who are within 50 miles of the damaged Japanese nuclear power plants should evacuate, there has been a lot of speculation as to why the NRC would recommend such a large evacuation zone when the guidance for the plume exposure pathway emergency planning zone in the United States is for an area approximately 10 miles in radius.

First, the NRC recommendation was based on specific US guidelines for radiation exposure and some sophisticated calculations of the possible radiation doses based on what is known or suspected to be happening at all of the Fukushima plants, so this NRC recommendation is very site-specific and incident-specific whereas planning guidance is based on a wide range of possible accident scenarios.

Secondly, the US guidance for emergency planning for commercial nuclear plants never established 10 miles as any kind of outer limit or maximum evacuation zone.  Rather, the US guidance is designed to require highly detailed response plans and preparedness for a 10 mile radius zone since that area is at greatest risk and has the least amount of time to evacuate. (more…)

Transportation Around Evacuation Areas of Fukushima Nuclear Plants

Friday, March 18th, 2011

Author: Justin Krometis, Transportation Analyst, IEM

I have participated in over a dozen evacuation studies over the last several years, many of them focused on nuclear plants, so I have been closely following the protective actions being taken around the Fukushima nuclear power plants in Japan. I wanted an easy way to look at the towns affected and the road network therein but I had not yet seen an interactive map that showed the locations of the plants and the areas covered by the evacuation and shelter orders. So I used the Google Maps API to create one.


What will we in the U.S. learn from the events in Japan?

Thursday, March 17th, 2011

Author: Gary Scronce, Director of Preparedness Programs, IEM

I’ve been asked the question a couple of times over the past few days by family and friends, some who know I work in homeland security and emergency management, some who know I spent more than 12 years as an engineer at a nuclear power plant. My answers have generally started with “It’s a little hard to tell right now, but a year or two down the road when more is known about the response operations to the earthquake, tsunami, and what is still evolving at the nuclear power plants, I’m sure there will be plenty of lessons that will affect how we approach things in the U.S.”

My answers start that way because it is still too soon and too hard to tell what is truly going on there from here in the U.S. With regard to the earthquake, I believe we will learn a lot more about how well various structural designs, including those specifically designed to mitigate the effects of an earthquake, really behave in an earthquake this severe. From an engineer’s perspective, there are few substitutes for data from failure analysis of full-scale structures to tell you what will really happen, what variables may not have been considered, and how to design against a similar failure.

Certainly lessons will be learned about what went well and not so well regarding Japan’s response to the earthquake and tsunami. I think this will be particularly true with regard to the need to provide for the basic needs of so many displaced people resulting from what was largely a no-notice event. (more…)

Nuclear Terminology: Getting It Right, Part II

Tuesday, March 15th, 2011

Author: Debbie Kim APRN, MSN, Sr. Health Care System Analyst, IEM

This morning on National Public Radio, I heard reports of the third reactor fire in Japan, and a fire now in a storage area. They are reporting an hourly release of radiation into the environment. To follow up on Gary Scronce’s previous blog post (Nuclear Terminology: Getting it Right), I wanted to discuss radiation measurement. The CDC Radiation Emergencies website explains it all very clearly. As Gary wrote, there is a difference between emitted radiation and absorbed radiation dose. To measure both, a sensor needs to be in place to provide that measurement. As a nurse, part of what I have always done is to teach patients and their families about treatments and their effects.

Just to make things more confusing there are different naming conventions for describing radiation that is emitted into the environment—radiation dose and radiation risk. There are “conventional units” (or terminology) that some of us old-timers remember such as the Curie (Ci), rad and rem. Then there is the newer System Internationale (SI) that uses the terms becquerel (Bq), gray (Gy) and sievert (Sv). Reporters have been using both versions of the terminology to describe the events surrounding the fires around the reactor site in Japan. (more…)

Nuclear Terminology: Getting it Right

Monday, March 14th, 2011

Author: Gary Scronce, Director of Preparedness Programs, IEM

On Sunday morning, March 13, 2011, I was reading an AP story entitled “Japan fights nuclear threat” by Eric Talmadge and Yuri Kageyama that really pounded home for me again the need to educate the press and public at large prior to potential disasters, particularly ones involving radiation and nuclear plants.

In talking about the blast at one of the Fukushima reactors, the article says,

“Nine residents of a town near the plant who later evacuated the area tested positive for radiation exposure, though officials said they showed no health problems.”

Japan Earthquake and Nuclear disaster

Residents evacuated from areas surrounding the Fukushima nuclear facilities damaged in Friday's massive earthquake, are checked for radioactive contamination, Sunday, March 13, 2011, in Koriyama city, Fukushima prefecture, Japan. (AP Photo/Wally Santana)

This choice of words perpetuates a fairly common misunderstanding about the difference between radiation and radioactive contamination. It is not possible in general to test someone for exposure to radiation unless they happened to be wearing some sort of dosimetry when they were exposed. For instance, if you get a medical X-ray, then go down the street to a laboratory it would not be possible for them to run a test and tell if you had the X-ray or not. What these people were likely tested for was radioactive contamination, the presence of particles of radioactive material on their skin or clothing. Unless some of that material was inhaled or ingested, it can be removed through decontamination, stopping the exposure they were receiving from the contamination. (more…)