首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
All U.S. nuclear weapons production facilities are presently closed down, and if the various agreements are adhered to, those fa
All U.S. nuclear weapons production facilities are presently closed down, and if the various agreements are adhered to, those fa
admin
2009-04-26
38
问题
All U.S. nuclear weapons production facilities are presently closed down, and if the various agreements are adhered to, those facilities will never be required except for one critical capability. All modern nuclear weapons use uranium(铀), plutonium(钚), and tritium(氚). Uranium and plutonium have very long half-lives, and there is large surplus of these materials.
Tritium, however, has a relatively short half-life of about 12.6 years, so about 5 percent of the amount on hand must be replaced each year to maintain the current inventory. (46)
Because of the large retirement of nuclear weapons by the United States in compliance with early agreements and national policy, tritium from retired weapons has been used to make up that lost through natural decay.
(47)
However, in about 10 to 15 years, depending on future negotiations, the United States will need a guaranteed supply of tritium to maintain its stockpile at whatever level is agreed on.
In anticipation of this future need to produce tritium, Defense Office Executive is pursuing two technologies. One uses a nuclear reactor that could also produce electricity whose sale would recover not only the capital cost of the reactor but also its annual operational cost. (48)
Unfortunately, the present Administration has a definite bias against nuclear power, so an alternative method is also being pursued even though it is agreed that it will cost twice as much as a reactor and use as much electricity as a reactor would produce.
This technology uses an accelerator to produce high-energy protons that in turn produce neutrons.
The main argument for the accelerator is that it produces no conventional nuclear wastes. (49)
Proponents readily admit that it will produce radioactive materials, but with a relatively short half-life compared with that of wastes from spent nuclear fuel.
The fact that the accelerator will require the equivalent of a nuclear power plant to supply its electricity is ignored.
(50)
Proponents ’also neglect to mention that about 22 percent of all electrical energy generated in the United States comes from nuclear power plants, so that 22 percent of the power used by the accelerator will generate conventional nuclear wastes, in addition to those the accelerator produces.
There is an alternative to either the reactor or the accelerator, which is simply to buy the required tritium from Canada or Russia.
选项
答案
美国依从早期的协定和国家政策,促使核武器大批量退役,所以这些退役核武器中的氚已经被用来补充自然衰减的氚。
解析
转载请注明原文地址:https://jikaoti.com/ti/8yURFFFM
0
考研英语一
相关试题推荐
ReadthefollowingtextandanswerthequestionsbychoosingthemostsuitablesubheadingfromthelistA-Gforeachnumberedpa
ReadthefollowingtextandanswerthequestionsbychoosingthemostsuitablesubtitlefromthelistA—Gforeachnumberedpara
ReadthefollowingtextandanswerthequestionsbychoosingthemostsuitablesubtitlefromthelistA—Gforeachnumberedpara
Onlyayearago,thesuitandtieseemedheadedforextinction—alongwithotherold-economyanomalieslikeprofits,provenprodu
Glaciersconsistoffallensnowthatcompressesovermanyyearsintolarge,thickenedicemasses.Mostoftheworld’sglacialic
Aftertakingabriefpausetoweathertherecession,aninvasionofBritainbysomeofAmerica’sbest-knownretailbrands—includ
Glaciersconsistoffallensnowthatcompressesovermanyyearsintolarge,thickenedicemasses.Mostoftheworld’sglacialic
BritishphysicistDr.JessWadehaswritten270Wikipediapagesfortrailblazingfemalescientistsinanefforttogeteverywom
FrankSinatraknewhewasgettingarawdeal.Hecouldsingbuthewasnotmuchofasongwriter,soheneversawacentwhenmos
FrankSinatraknewhewasgettingarawdeal.Hecouldsingbuthewasnotmuchofasongwriter,soheneversawacentwhenmos
随机试题
设有两个关系模式:职工(职工号,姓名,性别,年龄,职务,工资,部门号)部门(部门号,部门名称,经理名,地址,电话)依据上述关系回答下面小题。试用SQL语句定义一个包含姓名、性别、工资、职务和部门名称的视图ZBB。
接受捐赠的固定资产,按末来应交的所得税,贷记“应交税费——应交所得税”。()
会计工作交接完毕后,下列哪类人员可以不用必须在移交清单上签名或盖章()。
温州江心屿是中国四大名屿之一,屿中名胜古迹众多,最为有名的是()。
设定KPI指标和指标值时,一般不会选取()作为参考标杆。
搜查时,必须有被搜查人或者他的家属、邻居或者其他见证人在场。( )
简答语法规则的抽象性表现。
考生文件夹下存在一个数据库文件“samp3.accdb”,里面已经设计了表对象“tEmp”、窗体对象“fEmp”、报表对象“rEmp”和宏对象“mEmp”。试在此基础上按照以下要求补充设计:将窗体按钮“btnP”的单击事件属性设置为宏“mEmp”,以完
某模拟网站的主页地址是HTIP://LOCALHOST:65531/ExamWeb/INDEX.HTM,打开此主页,浏览“航空知识”页面,查找“运十运输机”的页面内容,并将它以文本文件的格式保存到考生目录下,命名为“yloysj.txt”。
ThemostfamouspainterinVictoria’shistoryisEmilyCarr.Whenshewasachild,shediscoveredthatwalkinginthewoods【C1】_
最新回复
(
0
)