According to the U.S. Nuclear Regulatory Commission, in 2015 there were 99 commercial nuclear reactors operating in the United States. In 2015, 4.1 × 10⁶ gigawatt hours of electricity were generated for use, and 19.5% of that was generated by nuclear power.

(a) A nuclear technician assumed that the products of the fission of ²³⁵U by one neutron were ⁹⁷Zr and ¹³⁷Te (see Problem 14.53). Ignoring decay products, the technician estimated the total mass of zirconium and tellurium in metric tons that would have to be disposed of in 2015 as nuclear waste (1 watt-hour = 3600 joules; 1 metric ton= 1000 kg). What was the technician’s result?

(b) Look up the half-lives of ⁹⁷Zr and ¹³⁷Te. When the waste was disposed of, do you think there was a measurable quantity of either isotope? Explain.

(c) Look up the decay mode of each isotope and write the decay series to a stable isotope for each one. Which decay series has a radioactive isotope that will remain in the waste for many years?

(d) Using the stable isotope products in your calculation, how far off was the technician’s estimate of total waste? Explain.

Data from Problem 14.53

How much energy is released in the fission of 1 kg of 235U according to the equation below? The experimentally determined masses of the products are 136.92532 u and 96.91095 u, respectively. 

Transcribed Image Text:

232U + n→ ¹32Te + %Zr + 2 n