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List of British manufactured joint service valves which may be radioactive - dated March 1961.

CV number Manufacturer Isotope Quantity per valve in microcuries
CV2248 * Ferranti H3 60µc approx.
CV2249 * " " 70µc approx.
CV2250 * " " 70µc approx.
CV2251 * " " 80µc approx.
CV2252 * " " 80µc approx.
CV2374 * " " 45µc approx.
CV2375 * " " 60µc approx.
CV2483 Nore Electric " 92µc approx.
CV5229 * Ferranti " 55µc approx.
CV5312 " " 40µc approx.
CV5384 Hivac " 3.5µc approx.
CV6028 Nore Electric " 10.5µc approx.

(note the symbol 'c' as published is an older symbol for the 'curie', now Ci)

* CV2248 to CV2252 inclusive, CV2374, CV2375 and CV5229 made before April 1961 contain Radium Bromide.

List of American manufactured British joint service radioactive valves showing British CV numbers and American tube types - March 1961. Note the information in Columns 3, 4 and 5 is extracted from SSC.347.

Column 1 Column 2 Column 3 Column 4 Column 5
CV number American type Manufacturer Isotope Isotope quantity per tube (microcuries)
508 1B49 West Ra 226 2.0
539 1B23 Bomac Co 60 0.15
Cent Co 60 0.5 to 1.0
576 1B26 Bomac Co 60 0.15
577 1B36 Bomac Co 60 0.25
713 1B27 Bomac Co 60 0.15
725 1B24 West Ra 226 2.0
761 1B22 Bomac Co 60 0.25
1793 724B Bomac Co 60 0.15
1832 0A2 Ray Co 60 0.0067
1833 0B2 Ray Co 60 0.0067
2573 5651 Ray Co 60 0.0067
2615 313C WE Ra 226 0.01
2626 346A - - -
- 346B WE Ra 226 1.0
2826 1B63A Bomac Co 60 0.15
Microwave Co 60 0.5
Syl Co 60 1.0
2914 1B40 Bomac Co 60 0.2
Syl Co 60 1.0
3539 6024 / ATR387 Bomac Co 60 0.45
3548 1B24A Bomac Co 60 0.15
Microwave Co 60 0.5
Syl Co 60 1.0
West Ra 226 2.0
3549 1B38 Bomac Co 60 0.9
3550 1B41 Bomac Co 60 0.25
West Ra 226 2.0
3628 1B35A Bomac Co 60 0.4
Syl Co 60 1.0
- 5791/X6007 Syl Co 60 1.0
- 446 AE Co 14 1.0
3745 1B58 - - -
- GL-1B58 GE Co 60 0.475
3877 1B56 Bomac Co 60 0.45
3897 5787 Ray Co 60 0.0067
3906 6117 Bomac Co 60 0.45
Microwave Co 60 0.5
Syl Co 60 1.0
3933 5783 Ray Co 60 0.0067
3960 5783WA Ray Co 60 0.0067
4020 0A2WA Hy Ni 63 0.01 to 0.05
Ray Co 60 0.0067
4028 0B2WA Hy Ni 63 0.01 to 0.05
Ray Co 60  
5062 5841      
5113 5787WA      
5186 5651WA Ch Ra 226 0.045 to 0.055
Ray Co 60 0.0067

Joint Services specification K1001 indicates that valves would not come into the radioactive class if they had less than a given amount as indicated in column 2 below. If a valve had more than one substance then provided the total did not exceed those in the table it still would not come into the radioactive class. E.g. if a valve had 0.8 microcuries of Krypton 85 then it has 80% of the permitted amount of that element. If it also contained 0.02 microcuries of Caesium 137 this would represent 20% of the permitted amount. Added together this is 100% and thus still within the total limit. In all cases the maximum permitted radiation dose rate allowed at surface of valve in millirads per hour was 0.01.

Column 1 Column 2
Substance Quantity allowed per valve in microcuries
Hydrogen 3 (H3) 1.0
Carbon 14 (C14) 1.0
Chlorine 36 (Cl36) 1.0
Cobalt 60 (Co60) 0.1
Nickel 63 (Ni63) 0.1
Krypton 85 (Kr85) 1.0
Caesium 137 (Cs137) 0.1
Thorium natural 0.1
Thallium 204 (Tl204) 0.1
Lead 210 0.1
Radium 226 0.1
Uranium natural (U238) 0.1

 

This file was last modified 15:52:12, Tuesday September 02, 2014