ML20037B721
| ML20037B721 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 05/19/1980 |
| From: | Milian L, Nicolosi S, Weiss A BROOKHAVEN NATIONAL LABORATORY |
| To: | |
| Shared Package | |
| ML20037B722 | List: |
| References | |
| RTR-NUREG-0686, RTR-NUREG-686 NUDOCS 8011100083 | |
| Download: ML20037B721 (2) | |
Text
_
nd e
May 19, 1980 'U1[is
~
/V u f f G-0676 SOLIDIFICATION AND LEACHING OF 00W VINYL ESTER-STYRENE WASTE FORMS CONTAINIcG "S-1 DECONTAMINATION WASTE CONCENTRATE l
A. J. Weiss, L. Milian, and S. L. Nicolosi l
Brookhaven National Laboratory I
Upton, NY 11973 1
l l
Introduction This work described in this report is a continuation of technical. assis-tance requested by C. Bishop on August 16, 1979.
Three reports were previously submitted concerning NS-1 decontami-3. tion waste, viz. September 18, 1979, October 31, 1979, and December 4, 19,9.
This report describes leach tests of NS-1 solidification waste forms and experimental problems encountered with so-lidification of one batch of NS-1 decertaminaticn solution concencrete.
Excerimental The NS-1 decentamination solutions used in these erperiments were cbtained frca Dow Chemical Cenpany in two five-gallon containers (lct #1128, barrel #17)
- hich we designated "NS-1A and NS-1B".
Previous data reported were derived frca experi ents perfcnned wi-h NS-1A. When cur supply of NS-1A was depleted, the NS-13 sample was concentrated to 43 weight % sclids by heating with a hot plate and Seat lamp as previously acccmplished for NS-1A. Analyse: cf NS-1A and NS-1B samples are sh
..n in Table 1.
I TEble 1 Analysis of NS-1 Waste NS-1 Waste NS-1 Waste As Received Concentrata NS-1A NS-IS NS-1A NS-13
~
dissolved solids (wt.%)
7.05 5.38 5?.0 42.5 Fe (p;m) 1275 1250 9500 9:00 Ni (ppm) 600 675 4"00 5130 pH 3.64 3.79 3
density 0 700C, (g/cm )
1.03 1.21 The NS-1A and NS-13 decontamination solutions as received from Duw were presumed to be taken from the same batch cf stock material.
NS-1 solutions are green before concentration and thus, the ccncentrate is also expected to be dark green. However, the MS-1B appeared to be darker and more viscous than the NS-1A. Visual ccmparison of the twc concentrates revealed the following 0011100gg)
\\
m t
differences: NS-1A concentrate was dark green, containing suspended floc; NS-1B concentrate was dark brown with a sludge-like consistency.
Closer examination of the NS-1B concentrate revealed the presence of finc carbon particles, which may be the result of improper heating during the concentratP,n process.
Solidification of the NS-1B concentrate with Dow vinyl ester-styrene mono-mer !101 in a waste: binder ratio of 1.5:1 by volume did not produce a prcduct comparable t; the good waste form reported earlier for NS-1A concentrate. The mixture obtained with NS-1B concentrate and vinyl ester-styrene resin was dark brown, whereas it should have been green. Upon mixing, only a partial emulsifi-cation was observed, and the solid form obtained was not as hard as that ob-tained with NS-1A concentrate.
Leach Tests One solidified sample of NS-1A concentrate and two of solidified NS-1B con-centrate were immersed in deicnized water for several weeks.
The NS-1A solid maintained gcod integrity while the NS-13 solids began to ex;and after 24 hcurs.
Af ter three days the NS-15 specimens expanded to approximately twice their crig-inal size, and after seven days began flaking.
The NS-1A solid form and one NS-1B solid form were leached in deicnized water by a modeled IAEA procedure involving complete renewal or. eachant a'it' each leach period.
The leachant volume was selected so that the volume to ;;ec-icen surf ace area was 10 cm.
Leaching characteristics of iron and n'ckel ccn-tained in the NS-1 concentrates were investicated over a 37 day ;ericd.
The tctal fractional release of iron was 2.0% frca the NS-1A waste form and 17f, frca
"? NS-IS waste form. The total fractional ' release of nickel frca sample NS-1A
- s reported here as less than 0.3%.
This value is a conservative p;er limit because the nickel concentration in many of the leach samples were beicw the detectable limit anc were assiv.ed the detectable limit in cal miating the total fractional release.
Nickel release frca the NS-13 solid was not determined.
Ccnclusions Additional experiments with NS-1 concentrates are needed to explain the cause cf the problems we en cuntered with its solidification with Dcs vinyl ester-styrene.
If the prc;erties of the NS-1 concentrate and subsecsent solidi-fication are sensitive to the method cf ccncentration, this needs to be under-s cod to prevent similar problems in solidificatica of actual decontamination solutions.
We cannot say much about the reproducibility of the process unless a sta-tistically valid number of tamples are prepared and leached.
On the basis of one sample, we can only estimate the iron diffusivity fron an apparently good 2
sample as 2 x 10-6 cm / day.
G 4
m
=
e
=--w ma em e
m mM O
w
-m m-e e
O e
m"S, 6
NO j
4 l
,f
)
Dw b'* W K
,: L i c. a ; L.< w a n.w gn 2 ap:+ un pu o
d
.- -. - o;.
.. t,=J-f il,m.. _[.c} (4 f6 _
m t
c
^
s, yh
]
1y s;
-- a
?
trRrw"*
'~
i l
l 1
l
.