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
2010-09-06
41
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
但是,未来10至15年内,根据未来的协商,无论就储存量达成何种商议,美国都需要保证氚的供给。
解析
转载请注明原文地址:https://kaotiyun.com/show/HLZ4777K
0
考研英语一
相关试题推荐
Accordingtotheauthor,theAmericaneconomicsituationis______.WhichofthefollowingstatementsisNOTmentionedinthep
TheCommitteeadoptedaresolution(requiring)thesevenautomakers(selling)themostcarsinthestate(making)2percentoft
AreportconsistentlybroughtbackbyvisitorstotheU.S.ishowfriendly,courteous,andhelpfulmostAmericansweretothem.
Readthefollowingtextcarefullyandthenwriteasummarybasedonit.Yourshouldwriteabout100words.(10points)I
CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootball,baseball,basketball
(46)Culture,inabroadsense,meansthetotalwayoflifeofapeople,includingthepatternsofbelief,customs,institutions,
Mostpeoplewouldbe(1)_____bythehighqualityofmedicine(2)_____tomostAmericans.Thereisalotofspecialization,agr
Thefollowingparagraphsaregiveninawrongorder.Youarerequiredtoreorganizetheseparagraphsintoacoherenttextbycho
Energywillbeoneofthedefiningissuesofthiscentury.Onethingisclear:theeraof(1)_____Oilisover.Whatwealldon
ManyforeignerswhohavenotvisitedBritaincallalltheinhabitantsEnglish,fortheyareusedtothinkingoftheBritishIsle
随机试题
有以下结构体说明、变量定义和赋值语句:structSTD{charname[10];intage;charsex;}s[5],*ps;ps=&s[0];则以下scanf函数调用语句有
女性,56.岁,5年前息乳腺癌手术治疗,术后化疗半年余,半年前发现左锁骨上淋巴结肿大,2个月来出现胸憋,气短就诊,化验检查Hb109g/L,WBC6×109/L,红细胞沉降率40mm/h,x线胸片示右肺肿块阴影,心影向两侧扩大,心脏搏动减弱。此时应
布氏杆菌中,对豚鼠致病力最强的是
患者男性,21岁。在某施工工地干活时不慎绊倒,造成右颊部贯通伤,出血较多如果口腔黏膜无缺损,而皮肤缺损较多,应采取的措施是
患部形小如栗,根深如钉,漫肿灼热。麻木疼痛者,为
A.指纹鲜红B.指纹紫红C.指纹青色D.指纹淡白E.指纹紫黑
A.大肠埃希菌B.双歧杆菌C.金黄色葡萄球菌D.铜绿假单胞菌E.艰难梭状芽胞杆菌与胆道感染相关的肝脓肿的常见致病菌是()
关于资金时间价值的影响因素,以下说法正确的是()。
转租合同的终止日期()原租赁合同规定的终止日期。
学前教育的公益性
最新回复
(
0
)