Typos, Errors and Clarifications (Updated Version)

We opened ourselves to receiving comments on the book, From Hiroshima to Fukushima to You, and did we ever receive them! From physicists, mechanical and nuclear engineers to doctors and lay people, most of the letters have been complementary. Unfortunately, a few errors or misunderstandings have occurred.

Typos: 

Page 26: Bismuth-208 should be bismuth-209.

Page 31: Astatine-219 should be astatine-218. Its half-life is actually about

                        1.5 seconds.

 Page 32: Figure 2.4 the first mentioned bismuth-210 should be

bismuth-214.

Page 86 & 90:  Plutonium-249 should be Plutonium 239.

Page 89: “Moderate” should be used instead of “modulate” and a

            “modulator” should be a “moderator”.

Page 177: Heavy water is deuterium oxide, not deuterium dioxide.

Downright Errors:

Page 30: The text erroneously says that neutrons don’t occur naturally – of course they do. Uranium-235 releases neutrons when it fissions.

Page 85: Figure 6.2 shows one U-235 fission producing three U-235 fissions and then possibly six U-235 fissions. This would not be a “controlled nuclear reaction”. Each generation should have the same number of fissions.

There are a number of areas where our readers and we differ on some of our interpretations of “how things work”.  We have enjoyed the discussions and look forward to more feedback.

Clarifications:

Page 2 and page 31:  We refer to “cosmic rays” and “gamma rays”. There is reason to be confused about the exact nature of the ionizing radiation reaching the surface of the earth from outside the atmosphere; see the Canadian Nuclear Safety Commission backgrounder at http://www.nuclearsafety.gc.ca/eng/resources/fact-sheets/natural-background-radiation.cfm 

Page 25: The damage to organic material when a neutron decays is done by the resulting proton and electron but technically, a neutron is not “made up of a proton and an electron”.

Both neutrons and protons are composed of quarks – a neutron is composed of two “down quarks” and one “up quark”. (http://www.youtube.com/watch?v=_nky2XQGQ3k) The decay of 10.3 minutes actually involves the transformation of one of the “down quarks” into an “up quark” turning the bulk of the neutron into a proton. The rest of the decay involves the emission of an electron and an antineutrino. (See http://hyperphysics.phy-astr.gsu.edu/hbase/particles/proton.html)  We chose not to introduce new subatomic particles to the reader; a neutron’s damage results from its ability to penetrate and from the resulting proton and the electron. 

Page 29: Several readers have pointed out to us that in Figure 2.3 “If the plastic or wood is thin enough, it won’t stop beta particles.” Correct. In fact, beta particles have a wide range of energies (however specific for specific radioisotopes) and the thickness required to stop them varies with their individual energies. Wood could be as thin as a centimeter and as thick as 31 cm (1 foot) or more!

Page 31: Astatine was not shown in the decay chain but mentioned in the text: It was omitted from figure 2.4 for simplicity. Polonium-218 decays to lead-214 and also to astatine-218. Astatine-218 decays two different ways: by alpha emission to bismuth-214 and by beta emission to radon-218 (which then decays to polonium-214 by alpha emission).

We continue to welcome your input.