[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
RE: Porcelain Electrical Insulators
Porcelain used for electrical insulation is made out of raw materials
normally containing 28 percent china clay, 10 percent fall clay, 35 percent
feldspar, 25 percent flint, and 2 percent talc (Electrical Engineer's
Handbook). The feldspar serves as a fluxing material to assist in
dissolving the more insoluable constituents, clay and quartz. The fledspar
and clays contain significant levels of K-40, RB-87, Th-232, and U-238
(NCRP-45; NCRP-94). We've detected several thousands of dpm on breakers
and insulators.
Randy Redmond
Radiological Control Organization
BWXT Y-12 L.L.C.
Oak Ridge, TN
865-574-5640
> -----Original Message-----
> From: Neil, David M [SMTP:neildm@id.doe.gov]
> Sent: Tuesday, April 29, 2003 1:15 PM
> To: ray ilson; radsafe@list.vanderbilt.edu
> Subject: RE: Porcelain Electrical Insulators
>
> Porcelain clay is detectably radioactive. Naturally, the sensitivity
> needed to detect it is related to the quantity. (As I discovered
> empirically early on in my career through taking a 'live' meter into
> multi-seat, tiled, restroom. :-D) Over and above that, some of the glazes
> are even more radioactive - not just Fiestaware Orange.
>
> The insulators I recall seeing were white porcelain with a brown glaze,
> and putting two and two together (and maybe getting 22) I wouldn't be at
> all surprised if they were easily detectable just from the natural
> constituents. I would doubt any intentional enhancement of radioactivity,
> since this would reduce the break-over voltage of the insulator.
>
> Dave Neil
>
> -----Original Message-----
> From: ray ilson [mailto:raymond.ilson@UTORONTO.CA]
> Sent: Tuesday, April 29, 2003 6:47 AM
> To: radsafe@list.vanderbilt.edu
> Subject: Porcelain Electrical Insulators
>
>
>
> Hello Radsafers!
>
> I have received a query about "Canadian Porcelain" electrical insulators
> used on high tension electrical distribution power lines. It appears
> that they are giving off radiation fields which were detected at the
> gate of a waste station. The insulators were manufactured in 1953-1954.
>
> I have not assessed these fields as yet but assume that the radioactive
> material is embedded within the porcelain itself rather than being a
> result of surface contamination, although both possibilities will be
> checked.
>
> Does anyone have any experience with such materials or could you direct
> me to further information?
>
> Many thanks, Ray
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
> You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/
>
> ************************************************************************
> You are currently subscribed to the Radsafe mailing list. To unsubscribe,
> send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
> radsafe" (no quote marks) in the body of the e-mail, with no subject line.
> You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/
************************************************************************
You are currently subscribed to the Radsafe mailing list. To unsubscribe,
send an e-mail to Majordomo@list.vanderbilt.edu Put the text "unsubscribe
radsafe" (no quote marks) in the body of the e-mail, with no subject line.
You can view the Radsafe archives at http://www.vanderbilt.edu/radsafe/