The production of electricity in nuclear power plants generates radioactive waste as a by-product. The waste is often placed in canisters (containers), but it remains radioactive for thousands of years, emitting invisible radiation that is harmful to humans and other living things. Scientists are currently discussing several strategies for safely storing the canisters; they need to be stored for thousands of years until the waste loses its radioactivity.
Surface Storage
One option is to store the canisters in permanent structures above ground. If properly constructed from a radiation-blocking material like concrete, such structures should remain sealed for thousands of years. Clear instructions would ensure the structures are properly maintained so that the material does not leak out and cause damage. In addition, signs with written warnings would be posted throughout storage sites to clearly indicate the purpose of the structures.
Borehole Disposal
Another option is to store the canisters in boreholes--long, vertical holes dug deep down into the earth. The waste would be lowered into the bottom of the borehole, and the remaining space filled and sealed with radiation-blocking material. Engineers already have considerable experience drilling boreholes for experimental purposes and oil exploration. In the proper area, boreholes are stable and relatively inexpensive to create.
lce Sheet Storage
Another solution is to store the canisters under the large, uninhabited surface of solid ice that has covered Antarctica for thousands of years. Radioactive waste produces a small amount of heat, so if a canister with waste were placed on the ice sheet, its heat would melt enough ice to allow it to sink farther and farther down. As it sinks, the melted ice layers above it would freeze again, sealing the waste off from the surface. Under this ice sheet, the waste should remain isolated from the surface long enough to lose its radioactivity.
The passage discusses nuclear waste disposal and puts forward several solutions to dispose of it safely. However, the lecture casts doubt on all of them by presenting serious counterarguments.
First and foremost, the article asserts that storing nuclear wastes above ground in permanent containers made of solid concrete that prevent leaking them with signs to alarm people would be practical. On the either hand, the professor calls this into question. He explicitly states that nuclear wastes will be stored for thousands of years therein people in that time probably would not use nuclear power, hence stopped maintaining it. Moreover, they may speak a different language resulting in not understanding the signs of nuclear waste's signs.
Secondly, the writer contends that boreholes down into the earth in the proper areas are reliable locations in which nuclear wastes could be stored. The speaker, conversely, points out that vertical boreholes are too narrow and should be widened twice to provide enough space which causes lots of stress thereby leaking radioactive wastes. Therefore, hardly does this solution work.
Last but not least, The author claims that inhabited solid ice sheets are able to store radioactive wastes for a long time even in case of leaking nuclear wastes produce heat melting the ice which allows waste to sink further. In contrast, the lecture clears out that due to climate change ice sheets are less satble, and they move to unexpected areas and contaminate there exposing huge risks.
Transition Words or Phrases used:
but, conversely, first, hence, however, if, may, moreover, second, secondly, so, therefore, in contrast
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 8.0 10.4613686534 76% => OK
Auxiliary verbs: 6.0 5.04856512141 119% => OK
Conjunction : 6.0 7.30242825607 82% => OK
Relative clauses : 11.0 12.0772626932 91% => OK
Pronoun: 17.0 22.412803532 76% => OK
Preposition: 31.0 30.3222958057 102% => OK
Nominalization: 2.0 5.01324503311 40% => More nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1283.0 1373.03311258 93% => OK
No of words: 242.0 270.72406181 89% => More content wanted.
Chars per words: 5.30165289256 5.08290768461 104% => OK
Fourth root words length: 3.94415379849 4.04702891845 97% => OK
Word Length SD: 2.52299377235 2.5805825403 98% => OK
Unique words: 157.0 145.348785872 108% => OK
Unique words percentage: 0.648760330579 0.540411800872 120% => OK
syllable_count: 387.0 419.366225166 92% => OK
avg_syllables_per_word: 1.6 1.55342163355 103% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 2.0 3.25607064018 61% => OK
Article: 8.0 8.23620309051 97% => OK
Subordination: 0.0 1.25165562914 0% => More adverbial clause wanted.
Conjunction: 1.0 1.51434878587 66% => OK
Preposition: 2.0 2.5761589404 78% => OK
Performance on sentences:
How many sentences: 11.0 13.0662251656 84% => Need more sentences. Double check the format of sentences, make sure there is a space between two sentences, or have enough periods. And also check the lengths of sentences, maybe they are too long.
Sentence length: 22.0 21.2450331126 104% => OK
Sentence length SD: 57.5743859486 49.2860985944 117% => OK
Chars per sentence: 116.636363636 110.228320801 106% => OK
Words per sentence: 22.0 21.698381199 101% => OK
Discourse Markers: 9.36363636364 7.06452816374 133% => OK
Paragraphs: 4.0 4.09492273731 98% => OK
Language errors: 0.0 4.19205298013 0% => OK
Sentences with positive sentiment : 3.0 4.33554083885 69% => OK
Sentences with negative sentiment : 7.0 4.45695364238 157% => OK
Sentences with neutral sentiment: 1.0 4.27373068433 23% => More facts, knowledge or examples wanted.
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.200480007501 0.272083759551 74% => OK
Sentence topic coherence: 0.0645637322373 0.0996497079465 65% => OK
Sentence topic coherence SD: 0.0625379432717 0.0662205650399 94% => OK
Paragraph topic coherence: 0.107677998345 0.162205337803 66% => OK
Paragraph topic coherence SD: 0.043935935152 0.0443174109184 99% => OK
Essay readability:
automated_readability_index: 14.5 13.3589403974 109% => OK
flesch_reading_ease: 49.15 53.8541721854 91% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 13.46 12.2367328918 110% => OK
dale_chall_readability_score: 9.1 8.42419426049 108% => OK
difficult_words: 67.0 63.6247240618 105% => OK
linsear_write_formula: 10.5 10.7273730684 98% => OK
gunning_fog: 10.8 10.498013245 103% => OK
text_standard: 11.0 11.2008830022 98% => OK
What are above readability scores?
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Rates: 90.0 out of 100
Scores by essay e-grader: 27.0 Out of 30
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Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.