1.Distinguish between energy efficiency and net energy. What do each of these measures tell us about an energy resource/technology? [2 Marks]

2. Some environmentalists have cheered, albeit somewhat reluctantly, the significant new reserves of natural gas made available because of advances in hydraulic fracturing and horizontal drilling.

a) Describe two reason for which an environmentalist might prefer gas over coal for electricity production. [2 Marks]

b) Explain one of the lingering concerns surrounding these new unconventional gas supplies. [1 Mark]

3. In the immediate aftermath of an oil spill on the open sea, where no emergency response occurs, which is at greater short-term risk from acute toxicity: life in the benthic zone or in the euphotic/pelagic zone? Explain why that risk decreases quickly (give two reasons). (Look in Chapter 7 to remind yourself of aquatic life zone definitions.) [2 Marks] 

4. What constitutes “safe” transport of petroleum and bitumen? Explain why you agree/disagree with a definition of safety that takes into account only the risk of harm to human health and economic harm. [3 Marks] 

5. Some opposition to oil pipelines is based on the risk of direct ecological damage that could be caused by a pipeline rupture. However, others have expressed opposition to pipelines because these “enable” continued use of fossil fuels. Regardless of the underlying reason, do you think it is fair to prevent the province of Alberta from delivering its petroleum and bitumen, both legal products and major resources, to foreign markets? Explain. [4 Marks]

6. Suppose you have the ability to watch atoms “live”. Specifically, you are viewing atoms of cobalt-60 which are unstable with a half-life of about 5.3 years:

a) First, you watch a single cobalt-60 atom. What can you say confidently about when its nucleus will decay? [1 Mark]

b) Next you watch a collection of 1000 cobalt-60 atoms. What statement can you make about when they will decay? [1 Mark]

7. Your friend is terribly afraid of radiation, so naturally her wealthy and mischievous younger brother offers her a choice for her birthday:

1) a day-long walking tour of Okuma (during which she may wear a mask), where the residual radiation dose (from the 2011 Fukushima accident, 10 km away) averages roughly 4 micro-Sieverts per hour above normal background, OR

2) dinner in far-from-Fukushima Tokyo where fresh fish caught just off the coast of Fukushima prefecture and rice grown near Okuma will be served. In the absence of any other information, which option would you advise your friend to choose, and why? (There is no secret third option…) [2 Marks]

8. In your own words, explain why spent nuclear fuel needs continuous cooling for at least ten years after its removal from the core of a reactor. [2 Mark]

the coure is NATS 1840 and it is assignment NO7