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Environmental
Contractor
Contractor ERC Team
Interoffice Memorandum
M. A. St. John x.0-19
40mm` Scc Below
°"7e l;ebruary 27.1999
0-o' S. L. Wi^ow
RadCun Eaginceriag
X3411531-070,
wuEcr. CVHlF FSTTMATE FOR S111PP1NC CONCRFTF. CORE SAMPLES
CCN: 055088
Job So. n1 92
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The 1•olluwing calculations show that cvn: satnplawith a direct reading of equal to or less than
400.000 dpm/100cm' will be below the de fi nitionafradimttive mate rial as defined in 49 CFR 173.40 3
of 70 Bq/g (2F.3 pCi/g). L'ach sample will consistofcoacrcte mate rial from Ibur, two inch co re
samples and enough wat er to make r slum consiotocy. The distrihution of radionuc lides is bussed tin
previous concrete samples taker from the below grade Fad Storage Basin that would also he
representative of these cuncrcte samples.
iven:
Cylinder Vulurrtc = ttr'h Radius ofcaocrcte core (r) = I inch
Concrete Density = 2.35 g/cm' Height of care sample taken (h) - 0.25 inches
27 pCi = Dq Maximum & Lt Wading on core = 40,000 dpm/ 1 UUcm'
2?2 dpm = pCi
Calculations:
V - (3.14) (1 in.)'(U 25in) =0.78 in' (16.4 cm'/irrl(4 mix samples) = 51.2 cm,
(400,000 dpm/51.2 cm') (cm'1235 g) = 3.32E3 dpdg
3.32ED dpm/g (pCi/2.2 dpm) = 1.SE3 pCi/g or 9.4 8419
SI.W:did
Percent Distribution(7) Concemratina (oC: i/c)
ACo 0.17 2.55 pCi/g
'rrCs 82 1.2F3 pCi/g
131 E 0.33 4.95 pCi/g
134 E 0.05 7.5E-1 pCi/g
'Sr 17 2.55E: pC ilg
741 Am 0. W5 7.5F Z pCi/g
n9 210p u 0.1 1.5
TOTAL: 1.460 PCi/g
C(2 j! 5E
S. 6. Marske X5 -53
P. A. Newman X3-41
RadCun Enginee ring File/LB X0-23
Document and into Se rvices 1 10-09 00001)