Studies of two-region subcritical uranium heavy water lattices

"February 1969.""MIT-2344-13."Some technical reports have the series numbering of MITNE-84Substantially the same as J.W. Gosnell's Ph. D. thesis in the Dept. of Nuclear Engineering, 1969Includes bibliographical references (leaves [212]-215)Reactor physics parameters were measured in eleven two-region subcritical assemblies moderated by heavy water. The regions of the assemblies consisted of nine different lattices of various fuel rod size, U235 enrichment, and spacing. The following parameters were measured in the assemblies: bare and cadmium-covered gold foil radial traverses; bare gold foil axial traverses; the ratio of epicadmium to subcadmium capture r tes in U238 (P28); and the ratio of fissions in U238 to fissions in U233(628)- From analysis of axial traverses at various radial positions, it was determined that the axial buckling was independent of radial position in the assemblies. A method was developed to apply the age equation to the experimental gold foil traverses. This analysis yielded the quantity [ ... ] for each region of the assemblies. Calculated values of [ ... ] were used to obtain values of the infinite multiplication factor from this parameter.For assemblies of sufficiently large inner regions, the values of km so found agreed within experimental uncertainty with independent determinations. The slowing-down spectra. arising from the age theory analysis were used to extrapolate two-region assembly measurements of P28 to critical assembly values. General agreement was found between these extrapolated values and the results of measurements made in full, single region lattices. The heterogeneous expressions for uncollided flux derived by Pilat were extended to two-region assemblies and used to determine single rod values of 628 from two-region assembly measurements. The theory was also used to predict values of 628 for each of the lattices composing the two-region assemblies. Both the single rod values and the full lattice predictions agreed within experimental error with previously reported results. The determination of material buckling from two-region subcritical assemblies is also discussed.!Because of the nature of the assemblies investigated, satisfactory measurements of the material buckling could not be made.U.S. Atomic Energy Commission contract AT(30-1)-234

The Reactor engineering of the MITR-II : construction and startup

Statement of responsibility on title-page reads: G. C. Allen, Jr., L. Clark, Jr., J. W. Gosnell, and D. D. Lanning"June, 1976."Also issued as a Ph. D. thesis by the first author, MIT Dept. of Nuclear Engineering, 1976Includes bibliographical references (pages 518-521)The heavy water moderated and cooled research reactor, MITR-I, has been replaced with a light water cooled, heavy water reflected reactor called the MITR-II. The MITR-II is designed to operate at 5 thermal megawatts. The MITR-I was shutdown in May, 1974, dismantling, construction, and preoperational testing continued until the MITR-II went critical on August 14, 1975. Cadmium absorbers were fixed in the upper core of the first fuel loadings to shorten the active core height and provide reactivity control. Solid non-fueled elements were also loaded for additional reactivity control. Swelling of the original cadmium fixed absorbers necessitated a second core configuration. The second core contained additional solid non-fueled elements and no fixed absorbers. The compact core of the MITR-II causes thermal neutron flux and power peaking to occur at the core outer boundaries and incore locations with excess moderator. The active core power density is in the!  range of 100 to 150 watts/cm 3 with peaks up to 300 watts/cm 3 . The power, flow, and temperature distributions of the initial core loadings were determined analytically and experimentally in order to evaluate the safety limit factor and limiting operating conditions. Neutron flux, core temperature, coolant flow, and power distributions were measured by various experimental techniques. The thermal-hydraulic parameters of the initial fuel loadings are evaluated and shown to satisfy the acceptance criteria for operation of the MITR-II

The Reactivity and transient analysis of MITR-II

Statement of responsibility on title page reads: Nuh Tolga Yarman A.F. Henry, D.D. Lanning, and J.W. Gosnell"July 1972."Originally written by the first author as a Ph. D. thesis, MIT, Dept. of Nuclear Engineering, 1972Includes bibliographical references (pages [191]-193)The two-dimensional, time dependent, three-group diffusion equations for the proposed designed core of the MIT reactor are written with an extra source term accounting for the photoneutrons generated in the D20 reflector. An analytical expression is developed for this term. Then an approximate flux composed of two spatial shapes chosen beforehand, each having an unknown time coefficient, is inserted into the time dependent multigroup equations and the weighted residual criteria is applied. This yields multimode kinetics equations with generalized definitions for the conventional matrix parameters: generation time, reactivity, delayed neutron (and photoneutron) fractions matrices. Computational methods for these parameters are presented. An accident concerning the withdrawal of the shim rods is examined with the code OZAN written for the purpose of-the computations required by the present work. This study suggests that a space-dependent analysis is required to analyse the accident postulated

Heavy water lattice project annual report / editors: Irving Kaplan, D.D. Lanning, T.J. Thompson ; contributors H. E. Bliss ... [et al.]

Statement of responsibility on title-page reads: editors: Irving Kaplan, D.D.Lanning, T.J. Thompson; contributors: H. E. Bliss, F.M. Clikeman, W.H. D'Ardenne, J.W. Gosnell, J. Harrington, III, I.Kaplan, H. Kim, D.D. Lanning, B.E.Malaviya, E.E. Pilat, A.E. Profio, E. Sefchovich. R. Simms, T.J. Thompson, G.L. Woodruff"September 30, 1963"Includes bibliographical referencesAnnual report; September 30, 1963U.S. Atomic Energy Commission contract AT(30-1)234

Heavy water lattice project annual report / editors: D.D. Lanning, I/ Kaplan [and] F.M. Clickeman ; contributors J. Barch ... [et al.]

Statement of responsibility on title-page reads: "Editors: D.D. Lanning, I. Kaplan, F.M. Clikeman; Contributors: J. Barch, N. Berube, F.M. Clikeman, W.H. D'Ardenne, J.W. Gosnell, J. Harrington III, I. Kaplan, B. Kelley, D.D. Lanning, B.K. Malaviya, L.T. Papay, E.E. Pilat, E. Sefchovich, A. Supple, T.J. Thompson, and G.L. Woodruff.""September 30, 1964.""MIT-2344-3."Includes bibliographical references (pages 165-168)Annual report; September 30, 1964U.S. Atomic Energy Commission contract AT(30-1)234

Heavy water lattice project annual report / editors: T.J. Thompson ... [et al.] ; contributors J. Barch ... [et al.]

Statement of responsibility on title-page reads: "Editors: T. J. Thompson, I. Kaplan, F.M. Clikeman, M.J. Driscoll; Contributors: J. Barch, N. Berube, H. Bliss, F.M. Clikeman, W.H. D'Ardenne, M.J. Driscoll, D.M. Goebel, J.W. Gosnell, H.M. Guéron, J. Harrington, III, S.P. Hellman, I. Kaplan, B. Kelley, D.D. Lanning, L.T. Papay, E.E, Pilat, C. Robertson, E. Sefchovich A. Supple, T.J. Thompson, and G.L. Woodruff .""September 30, 1965""MIT-2344-4."Includes bibliographical referencesAnnual report; September 30, 1965U.S. Atomic Energy Commission contract AT(30-1)234

Heavy water lattice project annual report / editors: T.J. Thompson, I. Kaplan, [and] M.J. Driscoll ; contributors J.H. Barch ... [et al.]

Statement of responsibility on title-page reads: Editors: T.J. Thompson, I. Kaplan and M.J. Driscoll; contributors: J. H. Barch, N.L. Berube, H.E. Bliss, K.D. Bowles, E J. Chase, H.S. Cheng, F.M. Clikeman, M.J. Driscoll, I.A. Forbes, D.Frech, J.W. Gosnell, T.L. Harper, J.Harrington, III, F.H. Hauck, M.G. Johnson, I. Kaplan, B. Kelley, L.T. Papay, E.E. Pilat, L.N. Price, N.C. Rasmussen, R.L. Ricketts, E. Sefchovich, S.S. Seth, A.T. Supple, T.J. Thompson, and G.L. Woodruff"September 30, 1966""MIT-2344-9."Includes bibliographical referencesAnnual report; September 30, 1966An experimental and theoretical program on the physics of heavy water moderated, slightly enriched lattices is being conducted at the Massachusetts Institute of Technology. During the past year, work was completed on studies of fast neutron distributions, lattices with added neutron absorbers, miniature lattices, two-region lattices, pulsed neutron source methods, and single,-rod experiments. In the past year, measurements were also completed on six lattices: three spacings each for 0.75-inch- and 0.387-inch-diameter, 0.947% enriched, uranium metal fuel.U.S. Atomic Energy Commission contract AT(30-1)234