Hi this is Sophia, the daughter of nuclear engineering professor Kai Vetter. I am accompanying him on his trip to Japan this upcoming week and I will blog about this visit. Our trip will take us to multiple locations, including Fukushima City, Koriyama City, Kawauchi Village, Hiroshima, Kyoto, and of course Tokyo. I’m really excited about this trip as I have never been to Japan. I will blog about my impressions, observations, and experiences of this country that I have heard so much about already, since my father has been to Japan many times over the last 5 years. I will also report on radiation measurements with a dosimeter my dad gave me.
To start off, I have measured the radioactivity at a location in the Bay Area with a Polimaster dosimeter. The dose rate I measure is low. This is because the Bay Area is at sea level, so less cosmic radiation can penetrate the atmosphere. Another reason is because the Bay Area contains very little radon, and I will explain later why that is. The number I observed was 0.12±0.3 uSv/h. uSv stands for micro-Sievert which measures the dose. uSv/h refers to the dose we receive per hour. This is called a dose rate. If we calculate how much radiation we get per year with this number, we have about 1,051 uSv, and then convert it to mSv by dividing the uSv by 1,000, we get about 1±0.3mSv. The ±0.3mSv shows the uncertainty that is provided by the dosimeter in %. The average natural radiation received in the USA is about 3 mSv, so the number we got is comparatively low. Another 3 mSv is received on average in the USA per year due to medical exams, for example from x-rays.