[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Sealed sources
A "sealed source" is not necessarily "rugged"; especially alpha sources with
thin windows. For lack of anything better, the best regulatory definition is
the one in 10CFR30.4, "Sealed source means any byproduct material [can be
extended to any radioactive material] that is encased in a capsule designed to
prevent leakage or escape of the byproduct material." My own practical
definition is that a sealed source is in a container which you must destroy to
open.
Here's to a risk free world, and other fantasies.
The opinions expressed are strictly mine.
Bill Lipton
liptonw@detroitedison.com
This is a situation in which the definition of "sealed source" in 10CFR4 is
not particularly helpful. I think most people have an idea of implied
ruggedness in the term "sealed source" which would not include a glass vial
however closed (but see below). I know that when I was inspecting I would
have questioned that kind of designation and brought the point back to the
office for a thorough discussion.
One correspondent suggested that a sealed source is one which meets the
requirements of 10CFR71.4 and 71.75. While this may be true in practice,
one should be careful because the provisions of 10CFR71 are for
transportation purposes.
ANSI has at least two documents on sealed sources:
ANSI N43.6 1977 (R1989) Classification of sealed radioactive sources
ANSI N42.16 1986 (R1993) Sealed radioactive check sources used in liquid
scintillation counters
I used "sealed" and "radioactive" as search terms on the ANSI web site. Of
course, ANSI standards are voluntary ones but the regulators may have
incorporated them by reference into their regulatory scheme or may accept
them as de facto standards. Why not call and ask. Some of us don't bite.
(Usual disclaimers.)
wayne johnston
nh bur rad hlth
6 hazen dr
concord, nh 03301-6527
603-271-4842
wjohnsto@dhhs.state.nh.us