129. 



6.3 Where the nuclear fuel is introduced in the reactor in aqueous 



solution the output of the reactor is directly processed to remove the 



waste. If the waste from the reactor is in solid form and included in 



the spent fuel elements, the waste is separated from the unconsumed 



uranium and plutonium in a chemical processing plant, in which the 



solids are dissolved and the waste thereafter separated by one of sev- 



(2\\ 

 eral methods . v ' 



6.4 Natural uranium contains one part of fissionable U in 139 parts 

 of fertile U" . Thus, if natural uranium is used as a fuel, it is pos- 

 sible to consume U ■" both to support the chain reaction and to give 

 excess neutrons which, when captured in U ^ , will produce plutonium 

 239. Theoretically, in power breeders, it is possible to produce more 

 Pu ' than the combined consumption of U 2 -" and Pu in the reactor. 



In a system where highly enriched U^^- 3 is used, Pu is not produced be- 

 cause of the absence of fertile U . If, in such a system, the reaction 

 proceeded until 30% of the initial U -* were consumed, approximately 

 250 grams of fission products would be produced per kilogram of U"5 

 charged. (22) Thus, from one metric ton of natural uranium irradiated 

 to 30% burn up of U , approximately 2 kg of fission products will be 

 derived. If enriched U "° were used as fuel, the quantity of fission 

 products per ton of charge would be increased, depending upon the ex- 

 tent of the enrichment. 



7. REQUIREMENT FOR NUCLEAR ENERGY 



7.1 It has been calculated that the fission of 1 gram of U D will pro- 

 duce approximately 24,000 kilowatt hours at 100% thermal efficiency. ' ' 

 The efficiency of production of electrical power from heat is usually 

 taken as 25% for statistical calculations^ ' 



7.2 The present installed capacity of electric utility generating stations 

 in the United States is about 115,000,000 kw (115,000 megawatts) . ( 25 ) 

 The production of electrical energy for the year ended January 31, 1956, 

 was 553,568,952,000 kwh; equivalent to 63,000,000 kw-years. This 

 represents an average load factor of about 55%. 



7.3 Estimates have recently been made that the installed capacity of 

 electrical plants will increase 8-fold during the next 50 years.'^"' The 

 installed capacity has in the past doubled as follows: (see Figure 7) 



25,000- 50,000 mw 1927-1946, 18 years; 



50,000-100,000 mw 1946-1954, 8 years. 



