Table 5. — Estimated annual variable costs for cobalt 60 and X-ray machine facilities, by hours of annual 



operation and size of facility, 1964 





: 2,000 hours (half year) 



: 4,000 hours (full year) 



Item 



: Cobalt d :. X-ray machine 



: Cobalt 60 :X-ra:/" machine 





: 1-kw. : 3-kw. : 3-kw. 



: 1-kw. : 3-kw. : - ■ . 



5- 

 6. 



7. 



Labor expense: l/ : 



2 technicians at $6,000 annual salary: 6.0 6.0 

 1 electronic engineer at $12,000 an- : 



nual salary : 



Source replenishment at 14 percent for : 



cobalt 60 2/ : 6.2 18.5 



Power-source replacement such as tubes : 

 and other parts for X-ray machine 3_/»-- '• 

 Electric power for conveyor and an- : 



ciliary equipment 4/ : 0.2 0.3 



Power inputs for X-ray machines 5_/ : 



Variable office and administrative : 



expense (overhead) : 6.0 6.0 



Variable maintenance and repairs : 

 (largely conveyor and ancillary elec- : 



tronic equipment ) : 4.0 5-0 



Other expenses directly related to the : 

 volume of output, including cost of : 



fuel and water : 0.3 0.4 



Allowance for contingencies 6/ : 1.5 3.0 



Total variable costs : 24.2 39.2 



6.0 

 6.0 



12.0 



0.3 

 2.7 



7.0 

 4.0 



0.4 

 4.0 



12.0 12.0 



6.2 18.5 



0.4 0.6 



12.0 12.0 



8.0 10.0 



0.6 0.8 



3.0 6.0 



42.4 42.2 59-9 

 Dollars 



12.0 

 12.0 



24.0 



0.6 

 5-4 



14.0 

 8.0 



84.8 



10. Average variable cost per kw.-hr. of : 



annual facility operation : 12.10 6.53 



7.07 



10.55 4.99 



7.07 



1/ Assuming 2 shifts, 5 days per week. Greater use of labor for maintenance was anticipated for X-ray 

 machine facilities than for cobalt 60 facilities (see assumption 5> P» 7) because of the difference in 

 use factors of these facilities. 



2/ 9,520 curies x 65 cents. Determined on the basis of 68,000 curies per kilowatt of facility size, 

 and a replenishment price estimated at 50 cents per curie plus 15 cents per curie for- encapsulation and 

 transportation . 



3_/ Estimated at $6 per hour for a 3-Mev. insulating core transformer, ICT 3000. 



4/ Determined from present commercial electricity rates for California, Florida, Louisiana , and Michigan 

 published by the Federal Power Commission. 



5_/ Determined from present industrial electricity rates for California, Florida, Louisiana, and Michigan 

 published by the Federal Power Commission. 



6/ Funds to pay for unpredictable cost items including those associated with downtime. 



Source: Estimates by the author based on: (1) research experience with cobalt 60 irradiators in the 

 United States and several foreign countries as explained by Otto A. Kuhl, L. E. Kukacka, and B. Manowitz, 

 Brookhaven National Laboratory, July 13, 1964; (2) research and commercial experience with electron and 

 X-ray machines revealed by representatives of the organizations listed in the preface, and from the 

 published sources listed in the. bibliography. 



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