Radiation safety regulatory issuesof Crookes tubes
in junior high and high schools
Ichiro Yamaguchi 1), Masafumi Akiyoshi 2)
NIPH1), Radiation research Center, Osaka prefecture UNIV 2)

1

Have you ever seena Crookes tube in a school?
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Yes

I have never seen2

Is it regulated?
Should we regulate it?
••   Yes

No3

IAEA: GSR Part 3• EXEMPTION AND CLEARANCE  
 – Radiation generators of a type approved by the regulatory body, orin the form of an electronic tube, such as a cathode ray tube for thedisplay of visual images, provided that:• (i) They do not in normal operating conditions cause an ambient dose
equivalent rate or a directional dose equivalent rate, as appropriate,exceeding 1 μSv/h at a distance of 0.1m from any accessible surface of theequipment; or• (ii) The maximum energy of the radiation generated is no greater than 5keV.

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http://www-ns.iaea.org/standards/review-of-the-bss.asp4

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http://www8.cao.go.jp/kisei/siryo/030919/09-2.pdf

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http://www.mext.go.jp/b_menu/shingi/chousa/gijyutu/004/004/attach/1267122.htm

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UK: Work with ionising radiation: Ionising Radiations Regulations 2017
Dose constraints for members of the public
155 Where employers anticipate that any work activity or facility is likely to expose members of thepublic to direct radiation or contamination, they should apply a dose constraint.
• It is recommended that the constraint on optimisation for a single new source should not exceed 0.3 mSv ayear.
• Employers should take this recommendation into account in establishing a dose constraint for members of thepublic.
• The constraint should be applied to estimates of dose for representative individuals likely to receive the highest
average dose from the work.
16