From: hawk@iastate.edu (John D Hawkinson)
Newsgroups: sci.physics.fusion
Subject: Re: Kamiokande and BYU experiments
Summary: portland cement as a radiation shield
Keywords: cold fusion, radiation detection, background radiation
Date: 12 Nov 92 04:17:20 GMT
Article-I.D.: news.BxL58w.5x
Organization: Iowa State University, Ames, IA

I remember cement was a problem when doing low-level counting work...in fact,
we usually kept the stuff away from our detectors....

Here's a reference I hope might help shed some light on the subject:
"Radioactivity in Consumer Products", NUREG/CP-0001, U.S. Nuclear Regulatory
Commission, August 1978.  The specific sections are:

p. 332-343, "Radioactivity in Building Materials" and
p. 351-368, "Radiation Exposure from Construction Materials Utilizing Byproduct
             Gypsum from Phosphate Mining".
 
In article <1992Nov11.101727.189@physc1.byu.edu> jonesse@physc1.byu.edu writes:

[everything not related to cement deleted -jdh]

 >(3) Cement experiment
 >We have found a clear random neutron emission from the portland cement mixed
 >with D2O at the level of 1X10-3 neutrons/second, which is, however, difficult
 >to explain based on radioactivity contamination in the cement, though more
 >data are clearly needed.  [Signal is about ten times the sensitivity level.]

I assume you're primarily concerned with the fissile materials, since they're
the ones that can decay through spontaneous fission?  Wollenberg & Smith gave 
values of 1.1 pCi/gm U-238 and 0.4 pCi/gm Th-232 for cements in general.

Cements utilizing byproduct gypsum from phosphate mining are even more 
"interesting".  Phosphate ore in the U.S. has concentrations of uranium and 
thorium.  When phosphatic fertilizers are produced, a large amount of phospho-
gypsum is formed as a byproduct.  About 20% of all phosphogypsum produced 
(1975 data) goes into PORTLAND CEMENT.

Phosphogypsum from Florida phosphates contains on average, 33 pCi/gm of
Ra-226, 6 pCi/gm U-238 and 13 pCi/gm Th-230.  Idaho-produced phosphogypsum
has 23 pCi/gm Ra-226...I don't have any numbers on U or Th, although the
proportions should be similar (I _think_ ).

 >(4)  More study
 >Several more data on teh portland cement + D2O are to be analyzed.  A system-
 >atic study of radioactive impurities in all the samples is underway.  The
 >final results critically depend on these studies and will be reported soon.

I wonder if you might have to do a Monte Carlo simulation of the system, as 
well...I hate to suggest it, because it's a *good* way of burning up an
enormous amount of computer time...

 >
 >As I have reported at recent scientific conferences, further studies on cement
 >+D2O at Kamiokande and in the BYU tunnel lab continue to show a "clear random
 >neutron emission" while the cement is curing (not after heat-curing).  The
 >cement+H2O samples show no signal in four tries.  We have transported these
 >cement+D2O studies to Provo from Kamiokande for two main reasons:  1- The 
 >neutron (clearly not gamma) signal from  the curing cement is sufficiently
 >large to interfere with neutrino measurements in the Kamiokande, so we looked
 >for another facility to pursue the path; 2- the Kamiokande is sensitive to
 >thermalized neutrons, and therefore to neutrons from (a particular concern)
 >deuteron photodisintegration induced by gammas from daughters such as thallium
 >208.  We have made an extensive study of this question (along with fission
 >neutrons and d(alpha,n) reactions) in the Provo Tunnel, and have not found
 >a fitting conventional explanation.  Moreover, we have a detector which
 >discriminates against the low-energy photodisintegration neutrons, and yet
 >the signal from fast-setting cement + D2O is seen in Provo.  Clearly, we
 >will not abandon the path as we have searched diligently for years for a
 >reliable neutron producer.  We are attempting to isolate the reaction(s)
 >responsible for the "clear random neutron emission" from setting cement +
 >D2O.  
 >Again I stress that the observed signals are very small and in no way support
 >claims of excess heat production in electrolytic cells by nuclear processes.
 >Sincerely,
 >Steven E. Jones
 >BYU 
 >

This last point may be worthless but, for what it's worth, the NUREG/CP noted 
(page 338):

   "A number of studies have been made, and others are in progress, on the 
    emanation of radon from various materials.  A few points of interest
    emerge.  One is that an increase in the water content of concrete or
    other porous material increases the emenation rate (Auxier, 1974)."

Any speculation as to what impact "radon puffs" from the drying concrete 
might have on the detector setup?
Newsgroups: sci.physics.fusion