Critical dimensions of systems containing /sup 235/U, /sup 239/Pu, and /sup 233/U: 1986 Revision Page: 63 of 205
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
HOMOGENEOUS HYDROGEN-MODERATED PLUTONIUM
PL1'TONITM SOLUTIONS, LOW " Pu
Plutonium solutions, nominally PuiNO3) h are not as stable as uraityl fluoride and aranyl
nitrate solutions.* The addition of nitric acid, one-half normal or greater, is necessary
to prevent t ile format ion of ploly er over most of t ile plut onium concent rat ic i range. At
300 g PutL and greater, polymer can appear -ven in the presence of nitric acid. For
comparison, urannyl fluoride solutions without exress acid may attain almost 1 kg U/L
w it hunt precipitation.
l'arly llauforl critical experiments xxith plutonium solutions, both spherical and cylin-
drie-d, are reported in Ref. 26. Results for wairr-retlected solutions are summarized in
Fi, 28 where there have been empirical adjust muients for Pu iand nitrat e contents. The
relations between H/Pu and Pu density of Table 7 are supplemented by Fig. 29, which
shows how that relation changes with HNO3 molarit y." Results are supported by Harwell
measurements on partially reflected solution."
An extensive program at Saclay led, among other results, to the data summarized in Table
I3.590-92 Further, supplementary Hanford critical data for solution spheres with various
reflectors are reported in Ref. 93 (see Fig. 30). Table 14 contains the items of Table 1 of
that report for which corrections for neck and support of spheres are available. Data for
reflectors of I.2 -cm-t hick paraffin, 10.2-cm-thick concrete, and concrete with gaps are not
included because such corrections are lacking. Reference 93 also includes critical masses
of hypothetical Y-phase2"Pu-water mixtures over a range of plutonium densities, from
calculations that give near agreement with experimental data.
Critical masses and volumes of water-moderated plutonium appear in Figs. 31 and 32,
diameters of infinite cylinders in Fig. 33, and thicknesses of infinite slabs in Fig. 34.2'9''95
Curves derived directly froni experiment al data apply to water-reflected Pu(N03)4 solution
with 1 N FIN03 and 3.1% 240Pu content of the plutonium. To show extreme hypothetical
departures from solution values, computed curves for ,:-phase plutonium-water mixtures
from Ref. 93 and Tables 15 and 16 are included in these figures.
The experimental value of infinite slab thickness that appears in Fig. 34 is derived from
Ref. 9-I. Adjustuants to I N H NO3 and 3.1% "Pu were empirical.
Te limiting critical concentrat ion in Figs. 31-34. 7.6 g 3"Pu/L. was deduced at Hanford
from specifications of a critical plutonium solution ili a 4-ft-diani sphere. " This compares
wit h ti) g "2tPu L as originally obtained front a Hanford Physical Const ants Test Reactor
(PCTR 1 ieasureuent '= and as reduced to 7.2 g = Pu 'L in a reexamination of the data,"'
* Eldon Christ ensen. Los Alamos National Laboratory. Los Alamos. N'.I (1985).
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Paxton, H.C. & Pruvost, N.L. Critical dimensions of systems containing /sup 235/U, /sup 239/Pu, and /sup 233/U: 1986 Revision, report, July 1, 1987; New Mexico. (https://digital.library.unt.edu/ark:/67531/metadc1109879/m1/63/: accessed March 19, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.