MONK Validation Report No. 25. - NRC: Home Page · ANSWERS/MONK/VAL. 1/25 1 October 1996 NRSmith MONK VALIDATION REPORT NO. 25 N R Smith AEA Technology Summary This report describes

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ANSWERS/MONK/VAL. 1/25

1October 1996NRSmith

MONK VALIDATION REPORT NO. 25

N R Smith

AEA Technology

Summary

This report describes the assessment of critical experiments as part of the validation study for theMONK computer code package. A summary of the system studied is given below:

Fissile Material:

Geometry:

Moderator:

Low-enriched (4.46 wt0/o U235) damp U308 powder (H:Uatomic ratio -0.77)

Array of cuboids of powder separated by moderating andabsorbing plates

Methyl Methaorylate Plastic plates separating powder cuboids

Neutron Poison:

Reflector:

Primary Reference:

PVC or steel absorbing platesSome cases with no absorbing plates

Plastic

R E Rothe, I Oh and G R GoebelCritical Experiments with Interstitially-Moderated Arrays ofLow-Enriched Uranium OxideNUREG/CR- 1071

Code Package: MONK7A

Reference: ANSWERS/MONK/VAL.1/25Page: 2

Version: IAuthor: N R Smith



DOCUMENT AZIENDMENT RECORD

Original Reference: ANSWERS/MONK/VAL.1/25

New Reference (if modified):

Document Title: MONK Validation Report No. 25

Version Date = Name Signature Date1 Oct 96 Author N R Smith

Checker N T Gulliford

Checker P R 'Ibome

Checker L Farrington

Approver N R Smith

List superseded versions:

Change requests incorporated in this amendment:

Amendments:

Distribution: ANSWERS MONK customers

Reference: ANSWERS/MONK/VAL. 1/25Page: 4

Version: IAuthor: N R Smnith

CONENTS

1. INTRODUCTION

2. EXPERIMENTAL DESCRIPTION

3. THE MONK MODEL

4. RESULTS

4.14.24.3

Standard CalculationsSensitivity AnalysisComparisons with Earlier Work

5. CONCLUSIONS

REFERENCES

APPENDIX A - MONK INPUT LISTINGS

TABLE 1.TABLE 2.TABLE 3.

EXPERIMENTAL CRITICAL PARAMETERSSUMMARY OF MATERIAL DATARESULTS OF MONK7A CALCULATIONS

TABLE 4. RESULTS OF EXPERIMENTAL UNCERTAINTY CALCULATIONS

FIGURE 1FIGURE 2.FIGURE 3.FIGURE 4.FIGURE 5.

FIGURE 6.

VIEW OF CAN SHOWING WATER INJECTION TECHNIQUEOVERALL VIEW OF EXPERIMENTAL ARRANGEMENTCATEGORY 0 EXPERIMENT - NORTH TABLECATEGORY U EXPERIMENT - NORTH TABLECATEGORY S EXPERIMENT - SOUTH TABLE WITH FILLING!REFLECTOR REMOVEDCATEGORY P EXPERIMENT' - SOUTH TABLE WITH FILLING/REFLECTOR REMOVEDVIEW OF EXPERIMENTAL CAN CONFIGURATIONSFIGURE 7.

Reference: ANSWERS/MONKNAL.1/25Page: 5

Version: 1Author: N R Smith

1. INTRODUCTION

This report describes the assessment of experiments performed as part of the validation study forMONK7A, which is a package comprising a Monte Carlo computer code and its standardUKNDL-based nuclear data library [1]. The experimental programme from which the experimentswere selected was performed at Rocky Flats in Colorado during 1979 [2]. Ten experiments arereported here each comprising an interstitially moderated array of aluminium cans containing damplow-enriched uranium oxide powder (H:U atom ratio - 0.77) with methyl methacrylate plasticreflection. Other experiments in the programme were reflected by concrete, but the potentialuncertainty in reported reflector composition imakes these less suitable for benchmark analysis. Intotal twelve plastic experiments were reported but two of these contained separating metal spacersthat, due to interpretation difficulties, would have increased the uncertainty in the calculation model.As these two added little to the data provided by the other ten it was decided to omit them from thisanalysis.

Details of the experiments, the MONK models of the experiments and the results obtained are givenin the following sections. The work file [3] contains detailed model construction notes and recordsthe location of the code input and output data. This experimental analysis has been given theMONK validation number 25.

2. EXPERIMENTAL DESCRIPTION

The experimental configuration comprised arrays of aluminium cans containing low-enriched (4.46wt0/o U235), slightly damp (H:U atom ratio - 0.77, equivalent to -1.8wt0/o water), compacted(density equal to 4.7 g/cm3) uranium oxide. Each array was constructed in two parts on a steel splittable machine and brought close together during an approach to critical series of measurements.The aluminium cans were interspersed with layers of neutron moderating and absorbing materials,and reflected on all sides by thick cubical shells composed of plastic. The parameters variedbetween experiments were: the thickness of interstitial moderating plastic, the composition andthickness of interstitial absorbing materials, the size of the critical array and the separation of the twoarray parts.

The experimental report contains a great deal of experimental detail which has been examined andinterpreted to produce the reasonably accurate calculation models used for the MONK analysis.Where approximations have been made (either by necessity or choice) these are described in thenext section. This section contains only an overview of the experimental detail and the interestedreader should refer to the experimental report to get a feel for the great care and attention to detailthat was apparently applied to these measurements. As this experimental report is part of the US.Nuclear Regulatory Commiission (NRC) Nuclear Regulation (NUREG) documentation, it isconsidered sensible not to repeat here material that is already more fully described in a standardregulatory reference document.



The fissile material was primarily U308, although a small amount of UO2 was detected Theprocedure employed for packing the cans and adding (and measuring) the water to obtain therequired H:U atom ratio is described in detail in the experimental report. A summary of the keypoints is included here. The powder was spooned into polythene bags and compacted in a press toa density of -4.7 g/ cm3. Each compacted block weighed -540 g and measured 7.5 cm squarewith one slightly rounded corner to match the aluminiurn can. Cubical alunminium cans (outsidedimension 15.28 (wide) by 15.28 (deep) by ]15.28cm (high), wall thickness 0.15cm) were used tocontain twenty-eight compacted blocks of powder (7 layers of four). The cans had small holesdrilled into two parallel sides, two equally spaced in the centre plane of where each compactedblock would appear when filled. These holes were used to inject the added water to anive at theH:U ratio of -0.77. (see Figure 1).

The amount of added water needed to reach the desired H:U atom ratio took into account the wateralready present in the oxide, together with the hydrogen present in the polythene bags (and minorquantities present in sealing tapes). Initial thoughts would suggest that this injection method mustproduce regions of saturated and dry powder. However it is considered that this is sufficientlyfundamental to the success of the experiments that it would have been taken into account in theexperimental design, so that the injection techmique would have been performed so as to minimiseany uncertainty in the homogeneity of the powider. The uncertainty associated with a variation indensity is considered in the sensitivity analysis discussed later.

As the water contained in the uranium oxide is such a key parameter for these experiments, thewater content was carefully measured by two independent methods. These methods were averagedfor each can used in the experiments. A curiosity of the experiments is that all cans demonstratedsome weight gain over the period of the experiments. Experiments were performed exposing cansto various environments, including humid atmosphere, for a prolonged period to ascertain the sourceof the weight gain. This was eventually attributed to the absorption of oxygen from the atmosphere,even though tapes had been used to seal the cans.

Eight types of experiment (called categories in the experimental report) were studied during theexperimental programme. However the exclusion of the metal spacer arrays means that only sevenare considered in this analysis. These are (using the designations from the experimental report [2]):

* Category 0 (Optimum moderation) - interstitial moderating methyl methacrylate plasticthickness of 2.44 cm resulting in the smallest critical array size

* Category U (Undermoderated) - interstitial moderating methyl methacrylate plastic thicknessof 0.929 cm resulting in the thinnest material for which criticality would occur

* Category S ('Supercans') - groups of 2xlx2 cans of oxide separated by 2.44cm moderatorthickness to investigate the effect of larger oxide batch sizes

Reference: ANSWERS/MONKNAL. 1/25Page: 7


* Category P (PVC absorber) - the same moderator thickness as category 0 and the cansare completely surrounded by 0.054 cm thickness PVC cladding. Certain industrial shippingcontainers for uranium oxide have a polyvinyl chloride packaging insert

* Category M (Mild steel absorber) - the same moderator thickness as category 0 and thecans are completely surrounded by 0.117 cm mild steel cladding. Many industrialoperations involving uranium oxide use steel containers.

* Category m (thin mild steel absorber) - the same moderator thickness as category 0 andthe cans are completely surrounded by 0.060 cm mild steel cladding.

* Category T (Thick steel/thin moderator) - the same steel thickness as category M but with1.23 cm thick interstitial moderator.

The reflector shell interior was large enough to accommodate a maximum of 5 (wide) by 5 (deep)by 5 (high) array of cans, with two layers (deep) placed on the north table and three layers (deep)placed on the south table. The shell interior can be seen in the experimental arrangement shown inFigure 2. However, the interior dimensions were not necessarily large enough to accommodate thearray plus the desired interstitial material. In fact all experiments had only four cans in the east-westdirection. Five cans could be assembled vertically with as much as 1.3 cm of interstitial materials,and this proved adequate for all cases studied. Five cans plus interstitial moderators exceeded theavailable depth in the north/south direction. This was solved by the use of reflector extensionshaving the same dimensions as the frames themselves but suitable thickness to provide the requireddepth.

As each experiment comprised a different number of cans and moderator arrangement, the insidecavity of the reflector shell necessarily exceeded the maximum size required. Whenever practical todo so, this space between the core and reflector was filled with blocks of plastic, effectively bringingthe reflector as close as possible to the core. One consequence of this is that the reflector is not ofconstant thickness in all directions. However even the minimum reflector thickness, 25cm, issufficient to provide isolation from the environment

Each 'half' of the array was stacked against a face-plate which separated the two parts as they werebrought together. Although the array ¶alves! did not touch, this separating plastic materialeffectively provided a near-uniform moderator arrangement across the whole array. In cases wherea full array height was not required, the base of the array was raised by the use of filler material.Typical table loadings are shown in Figures 3 to 6 with sketches of each configuration studied hereshown in Figure 7.

Measured parameters used in the validation study are given in Table 1. The ten experiments (2category 0, two U, one S, one P. two M, one m and one T) are given MONK validation numbers25.01 to 25.10, respectively.


Version: IAuthor: N R Smnith

3. THE MONK MODEL

The MONK models of the experiments have been constructed from the data presented inReference 2. However, it is important to note the following differences between the experimentsand the models used in the calculations:

(i) Temperature Effects

Cross section data within the MONK 7A nuclear data library are fixed at standard roomtemperature, 293K The actual temperature distribution of the experimental apparatus is notgiven but it is assumed that any difference would be small and have no significant effect onthe calculated values of k-effective. Any increase in temperature would result in an increasein the density. The impact on k-effective of a change in density is considered as part of asensitivity analysis.

(ii) Shape of the Cans

The cans used in the experiments had rounded edges but these have been modelled as beingperfectly square. An analysis of the difference has been performed (a volume difference of-0.5%) and it is considered that the effect on k-effective of the difference between theexperiment and model will be negligible compared with the other uncertainties.

(iii) Composition of the Oxide

The powder was pre-packed into polythene bags before being packed into the aluminiumcans. The MONK model assumes that the polythene of the bag is homogeneously mixedwith the oxide (due to the compression process this is not an unreasonable assumption).The MONK model also ignores the impurities present in the oxide powder. This is becauseof the very small quantities present, which would have a negligible effect on k-effective.Other minor components that have been ignored as being negligible are the polythene bagstwist-ties and sealing tapes used to hold the can lids in place. The hydrogen content of theseminor items is well within the uncertainty on the total hydrogen content of the oxide, and thislarger uncertainty is considered in the sensitivity analysis. The average oxide powderuranium composition and density was used for all cans with the effect of the uncertainties onthese average values considered by sensitivity analysis. The weight gain observed during thecourse of the experiments due to absorption of oxygen from the atmosphere is less than theuncertainty on the oxide density and so is considered covered by that sensitivity.

(iv) Stacking Gaps. Can Size and Plate Thickness



The outer extent of aluminium cans, interstitial moderator and, where present, absorbingmaterial when stacked and formed into an array were measured. This dimension did notequate to the value obtained by adding up the mean values of can dimension and platethickness. One cause of the discrepancy is clearly the fact that the cans and plates differedin dimensions about the mean value. Some information concerning the actual can and platethickness used for each configuration is given in the experimental report but it is notsufficiently clear to be utilised. Hence the average values have been used in the MONKmodels. The variations about these mean values are considered in sensitivity analyses.Another cause of the discrepancy is that the cans and plates are not uniform (i.e. thedimension or thickness varied across the surface). This would lead to small stacking gaps inthe array being present Analysis of the data confirmed that these gaps would be very smalland the effect on the calculated value of k-effective would be negligible given the overalldimensions of the experimental assembly. For the absorber clad cans the absorber plate isanother source of overall dimensional uncertainty and this is also considered in the sensitivityanalysis.

(v) Reflector Material

The experimental report states that inadvertently two different types of plastic had been usedfor the experiments, one a standard plastic and the other a fire-retardant variety. Someadvice on how to accommodate the different types in a calculation model is given but it isnot intended to be representative of the actual arrangement as the use of the two types wasnot readily separated. An alternative assumption is to inter-mix the compositions of the twotypes according to their relative quantities to create a smeared 'average' plastic material.The effect of this smearing is considered negligible given the large thickness of reflectorpresent and the similarities of the two plastic types. In addition, average inner and outerreflector dimensions are used in the calculation model rather than the independentlymeasured values for each experimental configuration. This has been done to simplify themodelling process. However given the thickness of the reflector, the effect of thesimplification is considered to be negligible.

(vi) Filler Density

As described above the space between the aluminium cans and the reflector shell was filledas much as possible with additional plastic of appropriate dimension. However due to theshapes of some of the gaps, complete in-filling was not possible. The experimental reportprovides an estimate of the amount of in-filling that was possible in terms of a percentage,with typical values being about 80%. As this is quite a large proportion of the volume andthe filler is itself surrounded by plastic reflector, an average smearing of the void gaps hasbeen performed by multiplying the plastic density for the filler material by the in-fillingpercentage. The effect of this assumption has been considered in the sensitivity analysis.

(vii) Neutron Source and Detectors



A small Cf252 source was positioned within the core and gradually removed as the twopartial arrays were brought together (and removed well outside the reflector beforecriticality appeared imminent). The effect of this source on the calculated results isconsidered negligible. Eight detectors were used for all configurations, with holes beingdrilled in the plastic reflector to accommodate the devices. The effect of these devices onthe calculated results is considered negligible due to their small size relative to the totalreflector volume.

(viii) Critical Separation Distance

No direct uncertainty on the critical separation distance is given in the experiment but it canbe determined from the positive and negative period measurements that the uncertainty is ofthe order of one or two in the last significant figure quoted. This uncertainty is considered inthe sensitivity analysis. The quoted positive and negative period measurement results alsohighlighted an error in the reported critical separation distance for case 25.04. The reportedseparation distance of 1.54 cm is less than both the positive and negative period values of1.83cm and 1.86cm, respectively. It has therefore been assumed that 1.54cm is a typingmistake and a value of 1.84cm has been used in the MONK calculation. The quoted valueof separation distance is used as part of the sensitivity analysis.

(ix) Brmine

Bromine is not present in the MONK7A UKNDL-based nuclear data library. It has beenrepresented in the plastic material as RulOl which has similar cross-section data [3].Inspection of the previous JEF-based library calculations reveals that a negligible number ofcollisions occur with Bromine making this approximation acceptable.

(x) Stainless Steel Compositions

Minor trace elements have been excluded from the material compositions used for thestainless steel table top and steel absorbers (thick and thin). The experimental referencereports a measurement uncertainty of a factor of two on each trace element concentrationand so have been included as iron. Since the trace elements account for approximately0.3wt/o of the steel absorbers and this steel causes at most 4% of the total absorption in thesystem, it is assumed that this will have a negligible impact on k-effective. No absorptionoccurs in the stainless steel table top so again the impact on k-effective of excluding thesetrace elements will be negligible.

The materials used in the MONK model are presented in Table 2. Each calculation employed1000 neutrons per stage and was run to achieve a precision better than 0.0014 in k-effective. Thisensured that adequate statistical sampling was performed, which was verified by performing detailedchecking of the output The input specification and output for each calculation were independentlychecked. The results from two calculations using different random number seeds were averaged foreach experiment to give a combined statistical precision of about 0.0010 (1cr).



4. RESULTS

4.1 Standard Calculations

MONK7A calculations using its standard UKNDL-based nuclear data library have been performedas described above using the critical parameters given in Table 1. The results obtained from thecalculations are summarised in Table 3.

The calculations indicate that the Monte Carlo code MONK7A in conjunction with its UKNDL-based nuclear data library calculates the system multiplication for low-enriched damp uranium oxidepowders within 1.8% of unity with a mean value of 1.0101±0.0014. However an analysis of theexperimental uncertainties is required to see whether the difference between calculated andmeasured is significant - this is considered below.

For the ten calculations the observed external standard deviation is 0.0045±0.0010 (compared withthe internal MONK estimate of the standard deviation of 0.0010). The MONK results for the tencases should be statistically consistent unless there are significant random uncertainties present in theexperiments or the accuracy of the code is a finction of one of the experimental variables. Analysisof the calculated values of k-effective as a fimction of the key parameters that vary between theconfigurations failed to identify a consistent trend, therefore suggesting that random experimentaluncertainties dominate this difference between the external and internal standard deviation.

However, there is an apparent reduction in the calculated values of k-effective when the separationdistance increases and those cases with a separation distance of greater than 1.Ocm have asignificantly lower average calculated value of k-effective than those below. As no explanation forthis can be identified and because the sensitivity analysis described below concludes that theseparation distance does not make a significant contribution to the total experimental uncertainty thisapparent trend has been discounted.

4.2 Sensitivity Analysis

The effects of the various uncertainties have teen examined to assess whether the above indicationof the accuracy of the code is sustainable. Both the calculation and the experiment have residualerrors/uncertainties that might affect the calculated value of k-effective. It is considered that theMONK model has been constructed with sufficient accuracy and the Monte Carlo sampling isadequate; therefore any deviations between the calculated and measured results are due either toerrorshuncertainties in the nuclear data library used in the calculations or errors/uncertainties in theexperiments.

Experimental Uncertainties



The significance of the experimental uncertainties was assessed by sensitivity analysis as part of theoriginal JEF-based library study of this experiment. A further series of MONK calculations wasperformed in order to assess the sensitivity of the system multiplication to the following modeluncertainties: oxide hydrogen content, oxide density, oxide uranium content, can size, moderatorplate thickness, filler density, absorber plate thickness and critical separation distance. One casewas considered sufficiently representative of the whole set for the purposes of obtaining an estimateof the experimental uncertainty. For all but the critical separation distance, Case 25.10 wasmodified to provide input to additional calculations. For the separation distance, Case 25.04 waschosen as the individual halves of the array anr the most reactive for this configuration and hence theeffect would be the largest. Although the sensitivity calculations were performed using a JEF-basednuclear data hlrary, it is considered that the results can be directly re-used for the current analysis,as the calculation of differences will remove the systematic effect of the library to the level ofaccuracy required.

The changes made to the reference case to compute the effect of each identified source ofuncertainty is given in Table 4, together with the computed reactivity effect. On this basis theexperimental uncertainty appears to be of the order of ±0.42% (1a) and on that basis the observeddifference between calculation and experiment might be due solely to experimental uncertainties.

Calculational Uncertainties

It should be noted that MONK uses only a prompt neutron fission spectrum and so the significanceof delayed neutrons needs to be considered. However considering low leakage of these systemsand the magnitude of the estimated experimental uncertainty for these experiments it is consideredthat this effect can be ignored.

4.3 Comparison with Earlier Work

These experiments have not previously been used as part of the MONK validation database [1], soit is not possible to make a direct comparison with earlier MONK results.

5. CONCLUSIONS

This report has shown that MONK7 in combination with a UKNDL-based nuclear data librarycalculates the system multiplication for damp low-enriched uranium oxide systems within +03% and+1.8% of unity, yielding a mean calculated value of k-effective of 1.0101±0.0014. Sensitivitycalculations have provided an estimated total experimental error ±0.42% (la). The mean value of1.01% over-prediction of k-effective by MONK7 is erefore statistically significant at the twostandard deviation level, but not at the three standard den iation level.

These experiments fall into the MONK7 categories 1 2 (121212) for cases 25.01, 25.02, 25.06,25.07, 25.08 and 25.09 and 138 (121322) for cases 25.03, 25.04, 25.05 and case25.10. Thedifferent categories are caused by the changes in resona ce absorption and fast fission.





REFERENCES

[I] MONK - A Monte Carlo Program for Nuclear Criticality Safety AnalysesUser Guide for Version 7AANSWERS/MONK(94)3 - February 1994

[2] R E Rothe, I Oh and G R GoebelCritical Experiments with Interstitially-Moderated Arrays of Low-Enriched UraniumOxideNUREG/CR-1071 - September 198()

[3] NCD/MONK/VAL/TW.25Work file for MONK validation experiment no.25RPSCD Archive, Winfrith.



Table 1 - EXPERIMENTAL CRITICAL PARAMETERS

MONK Experiment Configuration 2 Total number Critical In-fillingValidation Category' of cans Separation percentage (%)Number Distance

25.01 0 (b) 1 42 0.31 8825.02 0 (c) 43 1.52 8925.03 U (q) 100 1.05 7025.04 U (q) 100 1.84 3 7025.05 S (n) 74 0.68 7925.06 P (g) 56 0.42 9025.07 M () 60 0.23 8825.08 M (k) 62 1.28 8825.09 m (d) 51 0.24 8625.10 T (q) 100 0.70 84

Notes

I Experiment categories are:0 Optimum moderationU UndermoderatedS SupercansP PVC absorberM Mild steel absorberm Thin mild steel absorberT Thick steel/thin moderator

2 Configurations are denoted in terms of those used in the experimental report and depicted inFigure 6.

3 The experimental reference [2] reported a separation distance of 1.54 cm However this isless than both the reported positive and negative period values of 1.83cm and 1.86crn,respectively. It has therefore been assumed that 1.54cm is a typing mistake and a value of1.84cm has been used in the MONK calculation.



Table 2 - SUMMARY OF MATERIAL DATA

Material Density Nucide Compositiongc3

Uranium Oxide Powder 4.60 U234 3.8(weight ratios) U235 568.6

U236 10.2U238 12165.4O 2619.5H 42.5

. C 45.0Aluminium can 2.713 Al 99.36(weight /.) Si 0.10

Fe 0.42Cu 0.12

Moderator Plastic 1.185 H 7.83(weight /) C 59.49

. 0 32.48Filler and reflectorplastic 1.261 H 7.30(weight /) C 53.50

N 0.13Note actual filler plastic density for each case 0 30.34is obtained by multiplying by the in-filling P31 0.82percentage Cl 1.45

Br 5.68Steel table top 7.93 Cr 19.7(weight /o) Ni 10.3

Fe 70.0PVC absorber 1.318 H 5.25(weight /) C 42.52

O 1.66Cl 50.14

Thick steel absorber 7.863 Fe 99.595(weight /o) C 0.065

Mn 0.340Thin steel absorber 7.863 Fe 99.636(weight °/0) C 0.034

Mn 0.330



Table 3 - RESULTS OF MONK7A CALCULATIONS

MONK k-effective - k-effeclive - MeanValidation run 1 run 2 k-effectiveCase No.

25.01 1.0115 (0.0014) 1.0123 (0.0014) 1.0119 (0.0010)

25.02 1.0048 (0.0014) 1.0055 (0.0014) 1.0052 (0.0010)

25.03 1.0081 (0.0014) 1.0066 (0.0014) 1.0074 (0.0010)

25.04 1.0042 (0.0014) 1.0035 (0.0014) 1.0039 (0.0010)

25.05 1.0136 (0.0014) 1.0148 (0.0014) 1.0142 (0.0010)

25.06 1.0158 (0.0014) 1.0188 (0.0014) 1.0173 (0.0010)

25.07 1.0098 (0.0014) 1.0068 (0.0014) 1.0083 (0.0010)

25.08 1.0053 (0.0014) 1.0074 (0.0014) 1.0064 (0.0010)

25.09 1.0112 (0.0014) 1.0157 (0.0014) 1.0135 (0.0010)

25.10 1.0108 (0.0014) 1.0153 (0.0014) 1.0131 (0.0010)

Notes

The figure in brackets for the individual calculations is the standard deviation estimated by MONKFor the mean value the figure in brackets is the standard error on the mean value computed using thestandard deviations from the two independent calculations.



Table 4 - RESULTS OF EXPERIMENTAL UNCERTAINTY CALCULATIONS

MONK Parameter Uncertainty Mean Reactivity Worth forValidation Considered (lo)' k-effective 1 a change 2

Case No. for 10a changes (Niles)

25.10 Reference Case 0.9986 (0.0010)

25.10S1 Hydrogen content of 2.6 g 1.0366 (0.0010) 0.0037 (0.0001)oxide (per can)

25.10S2 Oxide density 3 0.01 E/Cm 3 1.0015 (0.0010) 0.0003 (0.0001)

25.10S3 Uranium content of 33 g 0.9975 (0.0010) 0.0001 (0.0001)oxide (per can)

25.10S4 Can size 0.02 cm 0.9946 (0.0010) 0.0004 (0.0001)

25.10S5 Plate thickness 0.01 cm 0.9863 (0.0010) 0.0012 (0.0001)

25.10S6 Filler density 5% 4 0.9964 (0.0010) 0.0002 (0.0001)

25.10S7 Absorber plate 0.002 cm 1.0137 (0.0010) 0.0015 (0.0001)thickness

25.04 Reference Case 0.9880 (0.0010)

25.04S8 Critical separation 0.03 cm 0.9914 (0.0010) 0.0003 (0.0001)distance

Total 0.0042 (0.0003)

Notes

2

2..

Except where noted, these have been taken from the experimental report.

The reactivity worth is computed by subtracting the inverse k-effective from the inverse k-effective for the reference case and dividing by 10.

3. The oxide density uncertainty has been computed from the uncertainty on the mass of allconstituents of the oxide and covers the; weight gain arising from oxygen absorption.

4. This has been estimated based on the likely uncertainty in being able to measure the effectivefiller density.



Figure 1 VIEW OF CAN SHOWING WATER INJECTION TECHNIQUE



Figure 2 - OVERALL VIEW OF EXPERIMENTAL ARRANGEMENT



Figure 3 - CATEGORY 0 EXPERIMENT - NORTH TABLE



Figure 4 - CATEGORY U EXPERIMENT - NORTH TABLE



Figure 5 - CATEGORY S EXPERIMENT - SOUTH TABLE WITHFILLING/REFLECTOR REMOVED

Reference: ANSWERS/MONKNVAL.1/25Page: 24


Figure 6 - CATEGORY P EXPERIMENT - SOUTH TABLE WITHFILLING/REFLECTOR REMOVED



Figure 7- VIEW OF EXPERIMENTAL CAN CONFIGURATIONS

Configuration (b) - Case25.01

Configuration (d) - Case25.09

Configuration @) - Case25.07

Configuration (c) - Case 25.02

Configuration (g) - Case 25.06

Configuration (k) - Case 25.08

Configuration (n) -Case25.05 Configuration (q) - Case 25.03,04 & 10


Version: 1Author: N R Srmith

APPENDIX A - MONK INPUT LISTINGS

Case 25.01

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.01*…-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

* Calculations performed by N R Smith - October 1995* Reported in ANSWERS/MONK/VAL/25

* Summary of experiment

* Fissile Material: Low enriched Uranium oxide powder* Geometry: Homogeneous blocks in aluminium cans* Moderator: Plastic* Neutron poison: None* Reflector: Plastic* Reference: R E Rothe, I Oh and G R Goebel* Critical Experiments with Intersitially-Moderated* Arrays of Low-enriched Uranium Oxide* NUREG/CR-1071

* September 1980

* Critical Parameter Data*…-- - - - - - -- -- -- - - - -- -- -

* Experiment 1 - Category 0 (optimum moderation)* Configuration (b)

* Number of cans = 42

* Critical separation of north and south cores = 0.31cm

* Important Notes*…-------------

* 1. Polythene bags assumed homogeneously mixed with powder* 2. Average block composition data used* 3. Powder impurities ignored* 4. Miscellaneous tapes ignored* 5. Curved can edges represented as square* 6. Average plastic composition used* 7. Filler percentage used to scale density (88%)* 8. Average inner and outer reflector dimensions used

BEGIN MATERIAL DATAMONK6 18 NUCNAMES

WGT 4.60 ! Ml - uranium oxide powderU234 3.8 U235 568.6 U236 10.2 U238 12165.4o 2619.5 J2H/H20 42.5 C 45

WGT 2.713 ! M2 - aluminium canAL27 99.36 SI 0.10 FE 0.42 CU 0.12

WGT 1.185 ! M3 - moderator plasticJ2H/CH2 7.83 C 59.49 0 32.48

WGT 1.110 ! M4 - filler plasticJ2H/CH2 7.30 C 53.50 N 0.13 0 30Y34 P31 0.82 CL 1.45 J2RU101 5.68

WGT 1.261 ! MS - reflector plastic

Reference: ANSWERS/MONKJVAL.1/25Page: 27


J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 PS1 0.82 CL 1.45 J2RU101 5.68

WGT 7.93 M6 - steel table top

CR 19.7 NI 10.3 FE 70.0

END***************************************B****************************************

BEGIN MATERIAL GEOMETRY

PART

BOXBOXBOX

BOX

1 NEST

BH3M4

M5

M3

! North core assembly

0.0 0.0 0.0 33.0 E8.44 50.72-5.87 0.0 -26.1 38.87 77.5 83.4-31.07 -25.6 -51.45 64.07 128.4 133.6

-31.07 -25.6 -51.45 65.3 128.4 133.6

PART

BOXBOX

BOX

BOX

2 NESTBH9

M4M5

M3

! South core assembly

0.0 0.0 0.0 33.0 68.44 50.720.0 0.0 -26.1 46.77 77.5 83.40.0 -25.6 -51.45 73.27 128.4 133.6-1.23 -25.6 -51.45 74.5 128.4 133.6

PART 3

BOX

BOX

BOX

PART 4

BOXBOX

CLUSTER

P1 0.0 0.0 0.CP2 65.61 0.0 C

MO 0.0 0.0 0.C

! Complete assembly

0 65.3 128.4 133.6

D.0 74.5 128.4 133.6

0 140.11 128.4 133.6

! Add steel table top

D 140.11 128.4 133.6

3 140.11 128.4 134.9

NEST

P3M6

0.0 0.0 0.00.0 0.0 -1.

END

BEGIN HOLE DATA

POLY

2 0

! Hl - aluminium can and contents

1 8 0.15 0.15 0.15

0.15 0.15 15.13

-2 8 0.0 0.0 0.0

0.0 0.0 15.28

0.15 15.13 0.15 15.13 15.13 0.150.15 15.13 15.13 15.13 15.13 15.130.0 15.28 0.0 15.28 15.28 0.0

0.0 15.28 15.28 15.28 15.28 15.28

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICEDCOSINES -l 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.31

! H2 - holes in can body

5 0.315 28*0 0 2

XYZMESH3 0.0 15.28

7 0.0 15.28

5 0.0 15.28-1 3 -1 3

3 3 3 3

-1 3 -1 3-4 3 3 3

4 -5 -1 .-7

0

17.72

17.72

17. 72

3 3

3 3

3 3

3 3

3 3

! H3 - north assembly

33.0

33.0 35.44 50.72 53.1633.0 35.44 50.72

-1 3 -1 3 33 -13

3 3 3 3 33 3 3 3

-1 3 -1 3 3 3 -1 3

3 3 3 3 33 3 i 3 3

-1 3 -1 3 3 3 -1 3

68.44

-l

3

-1

3-1

33

3

3-8

3

33

33

3

3

333

-13

-1

-44

33

3

3-5

-1

3

-1

3-1

PLATE

0 0 1 1 1.23 4 3! H4 - Filler/half-moderator Z segment

PLATE

1 0 0 1 1.21 3 4

! H5 - Filler/half-moderator X+ segment

Reference:Page:

Version:Author:

ANSWERS/MONK/VAL.1/2528IN R Smith

PLATE1 0 0 1 1.23 4 3

PLATE

0 1 0 1 1.21 3 4

PLATE

0 1 0 1 1.23 4 3

! H6 - Filler/ha:.f-moderator X- segment

! H7 - Filler/hal.f-moderator Y+ segment

! H8 - Filler/half-moderator Y- segment

XYZMESH

3 0.0 15.28

7 0.0 15.28

5 0.0 15.28

-1 3 -1 3

3 3 3 3

-1 3 -1 3

3 3 -4 3

-1 -6 4 3

0

17.72

17.72

17.72

3 3

3 3

3 3

3 -4

3 4

! H9 - south assembly

33.0

33.0 35.44 50.72 53.16 68.44

33.0 35.44 50.72

-1 3 -1 3 3 3 -1 3

3 3 3 3 3 3 3 3

-1 3 -1 3 3 3 -1 3

3 3 -4 3. 3 -4 3 3

-1 -6 4 3 3 4 -1 -6

-1

3-1-44

33333

33333

333

-44

-1

3-13-1

3333

-6

-13

-1-4

4

END*************************************** ** *** ** * ** ** ** ** * **** * *** ** * ** *** * ** ** ** *

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END**************************************** *********t*******************************

BEGIN SOURCE GEOMETRY

ZONEMAT ZONE 1 PART 4 / MATERIAL 1

END

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.02

* MONK VALIDATION CALCULATIONS - EXPERINENT 25.02*…-- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


* Summary of experiment*…--- -- - --- - - --- - - - --

* Fissile Material: Low enriched Uranium oxide powder* Geometry: Homogeneous blocks in aluminium cans* Moderator: Plastic* Neutron poison: None* Reflector: Plastic* Reference: R E Rothe, I Oh and G R Goebel* Critical Experiments with Intersitially-Moderated* Arrays of Low-enriched Uranium Oxide

NUREG/CR-1071* September 1980

* Critical Parameter Data

* Experiment 2 - Category 0 (optimum moderation)* Configuration (c)* Number of cans = 43* Critical separation of north and south cores = 1.52cm

* Important Notes*…--- -- ------ --



WGT 4.60 ! Ml - uranium oxide powderU234 3.8 U235 568.6 U236 10.2 U238 12165.4O 2619.5 J2H/H20 42.5 C 45

WGT 2.713 M2 - aluminium canAL27 99.36 SI 0.10 FE 0.42 CU 0.12


WGT 1.122 ! M4 - filler plasticJ2H/CH2 7.30 C S3.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

WGT 1.261 ! MS - reflector plastic


Version: IAuthor: N R Srnith

J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68


CR 19.7 NI 10.3 FE 70.0

END*BG******************************************************************************


PART

BOX

BOX

BOX

BOX

1 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 33.0 68.44 50.72

-6.37 0.0 -26.1 39.37 77.5 83.4

-31.57 -25.6 -51.45 64.57 128.4 133.6

-31.57 -25.6 -51.45 65.8 :.28.4 133.6

PART

BOX

BOX

BOX

BOX

PART

BOX

BOX

BOX

PART

BOX

BOX

2 NEST

BH9

M4

M5

M3


0.0 0.0 0.0 33.0 68.44 50.72

0.0 0.0 -26.1 47.87 77.5 83.4

0.0 -25.6 -51.45 74.37 128.4 133.6

-1.23 -25.6 -51.45 75.6 128.4 133.6

3 CLUSTER

P1 0.0 0.0 0.0

P2 67.32 0.0 0.0

MO 0.0 0.0 0.0

Complete assembly

65.8 128.4 133.6

75.6 128.4 133.6

142.92 128.4 133.6

Add steel table! top

142.92 128.4 133.6

142.92 128.4 134.9

4 NEST

P3M6

0.0 0.0 0.00.0 0.0 -1.3

END***************************************, ****************************************

BEGIN HOLE DATA

POLY ! H1 - aluminium can and contents

2 0

1 8 0.15 0.15 0.15

0.15 0.15 15.13

-2 8 0.0 0.0 0.0

0.0 0.0 15.28

0.15 15.13 0.15

0.15 15.13 15.13

0.0 15.28 0.0

0..0 15.28 15.28

15.13 15.13 0.15

15.13 15.13 15.13

15.28 15.28 0.0

15.28 15.28 15.28

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICEDCOSINES -l 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315

H2 - holes in can body

0.315 28*0 0 2

XYZMESH

3 0.0 15.28

7 0.0 15.28

5 0.0 15.28

-l 3 -l 3

3 3 3 3

-1 3 -1 3

-4 3 3 3

4 -5 -l -7

0

17.72

17.72

17. 72

3 3

3 3

3 3

3 33 3


33.0

33.0 35.44 50.72 53.16 68.44

33.0 35.44 50.72

-1 3 -1 3 3 3 -1 3 -1 3

3 3 3 3 3 3 3 3 3 3

-1 3 -1 3 3 3 -1 3 -1 3

3 3 3 3 3 3 3 3 3 3

-1 3 -1 3 3 3 -1 3 -1 -8

3

3

3

3

3

3

3

3

3

3

-13

-1-4

4

3

3

3

3

-5

-13

-1

3

-1

PLATE

0 0 1 1 1.23 4 3

! H4 - Filler/half-moderator z segment

PLATE

1 0 0 1 1.21 3 4

! H5 - Filler/half-moderator X+ segment



PLATE H6 - Filler/haLf-moderator X- segment

1 0 0 1 1.23 4 3

PLATE ! H7 - Filler/haLf-moderator Y+ segment

0 1 0 1 1.21 3 4

PLATE ! H8 - Filler/ha:Lf-moderator Y- segment

0 1 0 1 1.23 4 3

XYZMESH H9 - south assembly3 0.0 15.28 17.72 33.07 0.0 15.28 17.72 33.0 35.44 50.72 53.16 68.445 0.0 15.28 17.72 33.0 35.44 50.72-1 3 -1 3 3 3 -1 3 -1 3 3 3 -1 3 -1 3 3 3 -1 3 -1

3 3 3 333 3 3 3 3 3 3 3 3 3 3 3 3 3 3-1 3 -1 3 3 3 -1 3 -1 3 3 3 -1 3 -1 3 3 3 -1 3 -1

3 3 -4 3 3 3 333 3 3 3 3 3 -4 3 3 -4 3 3 -4-1 -6 4 3 3 -7 -1 3 -1 3 3 -8 -1 -6 4 3 3 4 -1 -6 4

0

END********************** *****************1t*********************** ** ** ** * **** ** * ** *

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END***************************************.* * * * ** **********************************



END**************************************fl **********************************f******

BEGIN ENERGY DATA

SCORING GROUPS 1615.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.03

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.03------------------------ …----------------------



* Fissile Material: Low enriched Uranium oxide powder* Geometry: Homogeneous blocks :in aluminium cans* Moderator: Plastic* Neutron poison: None* Reflector: Plastic* Reference: R E Rothe, I Oh and G R Goebel* Critical Experiments with Intersitially-Moderated* Arrays of Low-enriched Uranium Oxide* NUREG/CR-1071* September 1980

* Critical Parameter Data*…--- - - - --- - - -- - -- - -- --

* Experiment 3 - Category U (under-moderated)* Configuration (q)* Number of cans = 100* Critical separation of north and south cores = 1.05cm

* Important Notes-------- …------



WGT 4.60 ! MI - uranium oxide powderU234 3.8 U235 568.6 U236 10.2 U238 12165.4O 2619.5 J2H/H20 42.5 C 45


WGT 1.185 M3 - moderator plasticJ2H/CH2 7.83 C 59.49 0 32.48

WGT 0.883 ! M4 - filler plasticJ2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

WGT 1.261 ! M5 - reflector plastic



J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P.31 0.82 CL 1.45 J2RU101 5.68


CR 19.7 NI 10.3 FE 70.0

END**************************B*****************************************************


PART

BOX

BOXBOX

BOX

1 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 31.489 63.907 80.116

-0.281 0.0 0.0 31.770) 77.5 83.4

-25.481 -25.6 -25.35 56.970 128.4 133.6

-25.481 -25.6 -25.35 58.2 :L28.4 133.6

PARTBOXBOX

BOX

BOX

2 NESTBH4

M4

M5

M3


0.0 0.0 0.0 47.698 63.907 80.116

0.0 0.0 0.0 50.176 77.5 83.40.0 -25.6 -25.35 76.676 128.4 133.6

-0.924 -25.6 -25.35 77.6 :.28.4 133.6

PART 3

BOXBOXBOX

PART 4

BOXBOX

CLUSTERP1 0.0 0.0 0.CP2 59.25 0.0 CMO 0.0 0.0 0.C

! Complete assembly

58.2 128.4 133.6

0.0 77.6 128.4 133.6

0 136.85 128.4 133.6


D 136.85 128.4 133.6

3 136.85 128.4 134.9

NEST

P3M6

0.0 0.0 0.00.0 0.0 -1.

END

BEGIN HOLE DATA

POLY ! Hi - aluminium can and contents

2 0

1 8 0.15 0.15 0.15

0.15 0.15 15.13

-2 8 0.0 0.0 0.00.0 0.0 15.28

0.15 15.13 0.15 15.13 15.13 0.15

0.15 15.13 15.3.3 15.13 15.13 15.13

0.0 15.28 0.0 15.28 15.28 0.0

0.0 15.28 15.2E: 15.28 15.28 15.28

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICE ! H2 - holes in can bodyDCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315 0.315 28*0 0 2

XYZMESH

3 0.0 15.28

7 0.0 15.28

9 0.0 15.28

16.209

16. 209

16. 209


31.489

31.489 32.418 47.698 48.627 63.907

31.489 32.418 47.698 48.627 63.907 64.836 80.116

(-1 3 -1

21*3

(-1 3 -1

21*3(-1 3 -1

21*3(-1 3 -1

21*3

(-1 3 -1

0

3 3 3)*3 -1 3 -1

3 3 3)*3 -1 3 -1

3 3 3)*3 -1 3 -1

3 3 3)*3 -1 3 -1

3 3 3)*3 -1 3 -1

! H4 - south assemblyXYZMESH

5 0.0 15.28 16.209 31.489 32.418 47.698



7 0.0 15.28 16.209 31.489 32.418 47.698 48.627 63.9079 0.0 15.28 16.209 31.489 32.418 47.698 48.627 63.907 64.836 80.116(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1 3 -135*3

(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1 3 -1

35*3(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1 3 -135*3(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1 3 -1

35*3(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1 3 -10

END*************************************** *****************************************

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END*********.************* ***** ************* *** ****** *********** *** *****************



END

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.04

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.04* …____________________________________._________

* Calculations performed by N R Smith - July 1995

* Reported in ANSWERS/MONK/VAL/25

* Summary of experiment*…-- -- - - - - - - -- - - - - - --

* Fissile Material: Low enriched Uranium oxide powder

* Geometry: Homogeneous blocks in aluminium cans

* Moderator: Plastic

* Neutron poison: None

* Reflector: Plastic

* Reference: R E Rothe, I Oh and G R Goebel

* Critical Experiments with Intersitially-Moderated

* Arrays of Low-enriched Uranium Oxide

* NUREG/CR-1071

* September 1980

* Critical Parameter Data*…-- - -- - -- -- - - - - - -- -- --

* Experiment 4 - Category U (under-moderated)

* Configuration (q)



* Important Notes*…-- - -- - - - -- - --

* 1. Polythene bags assumed homogeneously mixed with powder

* 2. Average block composition data used

* 3. Powder impurities ignored

* 4. Miscellaneous tapes ignored

* 5. Curved can edges represented as square

* 6. Average plastic composition used* 7. Filler percentage used to scale density (70%)

* 8. Average inner and outer reflector dimensions used

BEGIN MATERIAL DATA

MONK

6 18 NUCNAMES

WGT 4.60

U234 3.8

0 2619.5

! MI - uranium oxide powder

U235 568.6 U236 10.2 U238 12165.4

J2H/H20 42.5 C 45

WGT 2.713 ! M2 - aluminium can

AL27 99.36 SI 0.10 FE 0.42 CU 0.12

WGT 1.185 ! M3 - moderator plastic

J2H/CH2 7.83 C 59.49 0 32.48

WGT 0.883 ! M4 - filler plastic

J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68




J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68


CR 19.7 NI 10.3 FE 70.0

END


PART

BOX

BOX

BOX

BOX

1 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 31.489 63.907 80.116

-0.281 0.0 0.0 31.770 77.5 83.4-25.481 -25.6 -25.35 56.970 128.4 133.6

-25.481 -25.6 -25.35 58.2 128.4 133.6

PART

BOX

BOX

BOX

BOX

2 NESTBH4

M4

M5

M3

! South core assembly0.0 0.0 0.0 47.698 63.907 80.116

0.0 0.0 0.0 50.170 77.5 83.4

0.0 -25.6 -25.35 76.670 128.4 133.6

-1.23 -25.6 -25.35 77.9 128.4 133.6

PART 3

BOX

BOX

BOX

PART 4

BOX

BOX

CLUSTERP1 0.0 0.0 0.0

P2 60.04 0.0 0

MO 0.0 0.0 0.0

! Complete assembly

58.2 128.4 133.6

.0 77.9 128.4 133.6

137.94 128.4 133.6


137.94 128.4 133.6

3 137.94 128.4 134.9

NEST

P3

M6

0.0 0.0 0.00.0 0.0 -1.

END

BEGIN HOLE DATA

POLY ! HI - aluminium can and contents

2 0

1 8 0.15 0.15 0.15

0.15 0.15 15.13

-2 8 0.0 0.0 0.0

0.0 0.0 15.28

0.15 15.13 0.15 15.13 15.13 0.15

0.15 15.13 15.13 15.13 15.13 15.13

0.0 15.28 0.0 15.28 15.28 0.0

0.0 15.28 15.28 15.28 15.28 15.28

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICE ! H2 - holes in can bodyDCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315 0.315 28*0 0 2

XYZMESH ! H3 - north assembly

3 0.0 15.28 16.209 31.489

7 0.0 15.28 16.209 31.489 32.418 47.698 48.627 63.907

9 0.0 15.28 16.209 31.489 32.4i8 47.698 48.627 63.907 64.836 80.116

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

XYZMESH ! H4 - south assembly5 0.0 15.28 16.209 31.489 32.418 47.698



7 0.0 15.28 16.209 31.489 32.418 47.698

9 0.0 15.28 16.209 31.489 32.418 47.698

(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1

35*3

(-I 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -135*3

(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1

35*3

(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1

35*3

(-1 3 -1 3 -1 3 3 3 3 3)*3 -1 3 -1

0

48.627 63.907

48.627 63.907 64.836 80.116

3 -1

3 -1

3 -1

3 -1

3 -1

END** * * ** ************************* ***** ** ***s******** ********************************

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END*************************************** * ******************************** ** ** * * *



END***************************************. ****************************************

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END

Reference:Page:

Version:Author:

ANSWERSIMONK/VAL.1/25381N R Smith

Case 25.05

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.05* …-----------------------------------------------


* Summary of experiment* …--------------------

*

*

Fissile Material:Geometry:Moderator:Neutron poison:Reflector:Reference:

Low enriched Uranium oxide powderHomogeneous blocks in aluminium cansPlasticNonePlasticR E Rothe, I Oh and G R GoebelCritical Experiments with Intersitially-ModeratedArrays of Low-enriched Uranium OxideNUREG/CR-1071September 1980

* Critical Parameter Data*…-- - - - -- - - - - -

*

Experiment 5 - Category S ('Supercan')Configuration (n)Number of cans = 74Critical separation of north and south cores = 0.68cm

* Important Notes*…-- - - - - - - - - - - -










J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68


CR 19.7 NI 10.3 FE 70.0

END**** ***************************************************************************


PART

BOX

BOX

BOX

BOX

1 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 33.0 63.56 63.56

0.0 0.0 0.0 33.0 77.5 83.4

-24.97 -25.6 -25.35 57.97 128.4 133.6

-24.97 -25.6 -25.35 59.2 2.28.4 133.6

PART

BOX

BOX

BOX

BOX

PART

BOX

BOX

BOX

PART

BOX

BOX

2 NEST

BH4

M4

M5M3


0.0 0.0 0.0 50.72 63.56 63.56

0.0 0.0 0.0 50.97 77.5 83.4

0.0 -25.6 -25.35 77.47 128.4 133.6

-1.23 -25.6 -25.35 78.7 128.4 133.6

3 CLUSTER !

P1 0.0 0.0 0.0

P2 59.88 0.0 0.0

MO 0.0 0.0 0.0

Complete assembly59.2 128.4 133.678.7 128.4 133.6138.58 128.4 133.6

Add steel table top138.58 128.4 133.6138.58 128.4 134.9

4 NEST

P3

M6

0.0 0.0 0.00.0 0.0 -1.3

END

BEGIN HOLE DATA

POLY

2 0

! Hl - aluminium can and contents

1 8 0.15 0.15 0.15

0.15 0.15 15.13

-2 8 0.0 0.0 0.0

0.0 0.0 15.28

0.15 15.13 0.15 15.13 15.13 0.15

0.15 15.13 15.13 15.13 15.13 15.13

0.0 15.28 0.0 15.28 15.28 0.0

0.0 15.28 15.28 15.28 15.28 15.28

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICE.DCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315

H2 - holes in can body

0.315 28*0 0 2

XYZMESH

3 0.0 15.28

5 0.0 15.28

5 0.0 15.28

(-1 3 -1)*2

(-1 3 -1)*2

15*3

(-1 3 -1)*2

(-1 3 -1)*2

0

17.72

30.56

30.56

3*3

3*3

! H3

33.0

33.0

33.0

(-1

(-1

- north assembly

48.28

48.28

3 -1) *2

3 -1) *2

63.56

63.56

3*3 (-1 3 -1)*2

3*3 (-1 3 -1)*2

XYZMESH

5 0.0 15.28

5 0.0 15.28

5 0.0 15.28

17.72

30.56

30.56

! H4

33.0

33.0

33.0

- south

35.44

48.28

48.28

assembly50.72

63.56

63.56

(-1 3 -1 3 -1)*2 5*3 (-1 3 -1 3 -1)*2(-1 3 -1 3 -1)*2 5*3 (-1 3 -1 3 -1)*2



25*3(-1 3 -1 3 -1)*2 5*3 (-1 3 -1 3 4)*2(-1 3 -1 3 4)*2 4*3 4 (-1 3 -1 3 4)*2

0

END

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END



END

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END

Reference:Page:

Version:Author:

ANSWERS/MONKNVAL.1/25411N R Smith

Case 25.06

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.06* …----------------------------------------------


*

*

*

*

*

*

Summary of experiment

Fissile Material: Low enriched Uranium oxide powderGeometry: Homogeneous blocks in aluminium cansModerator: PlasticNeutron poison: NoneReflector: PlasticReference: R E Rothe, I Oh and G R Goebel

Critical Experiments with Intersitially-ModeratedArrays of Low-enriched Uranium OxideNUREG/CR-1071September 1980

* Critical Parameter Data*…-- - - - - - - - - - -

* Experiment 6 - Category P (PVC absorber)* Configuration (g)* Number of cans = 56


* Important Notes*…-- - - - - - - - - - - -

* 1. Polythene bags assumed homogeneously mixed with powder* 2. Average block composition data used* 3. Powder impurities ignored* 4. Miscellaneous tapes ignored* 5. Curved can edges represented as square* 6. Average plastic composition used* 7. Filler percentage used to scale density (90%)* 8. Average inner and outer reflector dimensions used* 9. Exact fitting abosrber plates


WGT 4.60U234 3.80 2619.5

! Ml - uranium oxide powderU235 568.6 U236 10.2 U238 12165.4J2H/H20 42.5 C 45


AL27 99.36 SI 0.10 FE 0.42 CU 0.12





WGT 1.261 ! M5 - reflector plasticJ2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

WGT 7.93 ! M6 - steel table topCR 19.7 NI 10.3 FE 70.0

WGT 1.318 !M7 - PVC absorberJ2H/CH2 5.25 C 42.52 0 1.66 CL 50.14

END


PART

BOX

BOX

BOX

BOX

1 NEST

BH3M4

M5

M3


0.0 0.0 0.0 33.216 68.872 68.872-5.654 0.0 -10.1 38.870 77.5 83.4-30.854 -25.6 -35.45 64.07 128.4 133.6

-30.854 -25.6 -35.45 65.3 128.4 133.6

PARTBOX

BOX

BOX

BOX

2 NESTBH7

M4

M5

M3


0.0 0.0 0.0 33.216 68.872 68.8720.0 0.0 -10.1 46.77 77.5 83.40.0 -25.6 -35.45 73.27 128.4 133.6

-1.23 -25.6 -35.45 74.5 128.4 133.6

PART 3 CLUSTER !

BOX P1 0.0 0.0 0.0

BOX P2 65.72 0.0 0.0

BOX MO 0.0 0.0 0.0

Complete assembly65.3 128.4 133.6

74.5 128.4 133.6140.22 128.4 133.6

PART 4 NEST

BOX P3

BOX M6


0.0 0.0 0.0 140.22 128.4 133.60.0 0.0 -1.3 140.22 128.4 134.9

END

BEGIN HOLE DATA

POLY ! Hi - aluminium can and contents plus steel surround

ORIGIN 0.054 0.054 0.054

2 71 8 0.15 0.15 0.15 0.15 15.13 0.15 15.13 15.13 0.15 15.13 0.15 0.15

0.15 0.15 15.13 0.15 15.13 15.13 15.13 15.13 15.13 15.13 0.15 15.13

-2 8 0.0 0.0 0.0 0.0 15.28 0.0 15.28 15.28 0.0 15.28 0.0 0.0

0.0 0.0 15.28 0.0 15.28 15.2t; 15.28 15.28 15.28 15.28 0.0 15.28

LATTICE ! H2 - holes in can body

DCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315 0.315 28*0 0 2

XYZMESH

3 0.0 15.388 17.

7 0.0 15.388 17.

7 0.0 15.388 17.

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3

(-4 3 3)*7(4 -5 -1 4 3 3)*3

0

828

82882 8


33.216

33.216 35.656 51.044 53.484 68.872

33.216 35.656 51.044 53.484 68.872

-1 3 -1

-1 3 -1

-1 3 -1

4 -5 -1



PLATE H4 - filler/half-moderator Z segment

0 0 1 1 1.23 4 3

PLATE ! H5 - filler/haLf-moderator X+ segment

1 0 0 1 1.21 3 4

PLATE ! H6 - filler/haLf-moderator X- segment

1 0 0 1 1.23 4 3

XYZMESH ! H7 - south assembly

3 0.0 15.388 17.828 33.216

7 0.0 15.388 17.828 33.216 35.656 5:L.044 53.484 68.872

7 0.0 15.388 17.828 33.216 35.656 5:L.044 53.484 68.872

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3(-1 3 -1 3 3 3)*3 -1 3 -121*3

(-1 3 -1 3 3 3)*3 -1 3 -1

(3 3 -4)*7

(-1 -6 4 3 3 4)*3 -1 -6 4

0

END* ** ** * ** ** *** ****** *** ** * ** **** *** * ** * *,***** ** *** ***** * ** **** * ****** * * **** ** * ***

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * V. * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *



END* * ** ** * ****.** ** * **** *** * ** *** **** * * **** * * ** *** * *** *** * ** * ** *** *** *** ** *** * * *****

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END

Reference:Page:

Version:Author:

ANSWERS/MONK/VAL.1/2544NN R Smnith

Case 25.07

*

MONK VALIDATION CALCULATIONS - EXPERIMENT 25.07_____________________________________.._________

Calculations performed by N R Smith - October 1995Reported in ANSWERS/MONK/VAL/25

* Summary of experiment*…-- - - - -- - - - -

*

*

*

*

Fissile Material:Geometry:Moderator:Neutron poison:Reflector:Reference:

Low enriched Uranium oxide powderHomogeneous blocks in aluminium cansPlasticNonePlasticR E Rothe, I Oh and G R GoebelCritical Experiments with Intersitially-ModeratedArrays of Low-enriched Uranium OxideNUREG/CR-1071September 1980

* Critical Parameter Data* …----------------------

* Experiment 7 - Category M (Mild steel absorber)* Configuration (J)* Number of cans = 60* Critical separation of north and south cores = 0.23cm

* Important Notes_ _ _ _ _ _ _ _… _ _ _ _ _ _

* 1. Polythene bags assumed homogeneously mixed with powder* 2. Average block composition data used* 3. Powder impurities ignored* 4. Miscellaneous tapes ignored* 5. Curved can edges represented as square* 6. Average plastic composition used* 7. Filler percentage used to scale density (88%)* 8. Average inner and outer reflector dimensions used* 9. Exact fitting abosrber plates****************************************************************** ** ************


WGT 4.60U234 3.80 2619.5

! Ml - uranium oxide powderU235 568.6 U236 10.2 U238 12165.4J2H/H20 42.5 C 45




J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

Reference: ANSWERS/MONKNVAL.1/25Page: 45




CR 19.7 NI 10.3 FE 70.0

WGT 7.863 ! M7 - thick steel absorber

FE 99.595 C 0.065 MN 0.34

END


PART

BOXBOX

BOXBOX

1 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 33.468 69.376 69.376

-5.402 0.0 -10.1 38.870 77.5 83.4

-30.602 -25.6 -35.45 64.07 128.4 133.6-30.602 -25.6 -35.45 65.3 128.4 133.6

PART

BOXBOX

BOXBOX

2 NEST

BH3

M4

M5

M3


0.0 0.0 0.0 33.468 69.376 69.3760.0 0.0 -10.1 46.77 77.5 83.40.0 -25.6 -35.45 73.27 128.4 133.6-1.23 -25.6 -35.45 74.5 128.4 133.6

PART 3

BOXBOX

BOX

CLUSTER ! IP1 0.0 0.0 0.0P2 65.53 0.0 0.0

MO 0.0 0.0 0.0

Complete assembly

65.3 128.4 133.6

74.5 128.4 133.6

140.03 128.4 133.6

PART 4 NEST

BOX P3

BOX M6


0.0 0.0 0.0 140.03 128.4 133.60.0 0.0 -1.3 140.03 128.4 134.9

END********* ***********************************************************************

BEGIN HOLE DATA

POLY ! H

ORIGIN 0.117 0.117 0.117

2 7

1 8 0.15 0.15 0.15 00.15 0.15 15.13 0

-2 8 0.0 0.0 0.0 0

0.0 0.0 15.28 0

1 - aluminium can and contents plus steel surround

.15 15.13 0.15 15.13 15.13 0.15

.15 15.13 15.13 15.13 15.13 15.13

.0 15.28 0.0 15.28 15.28 0.0

.0 15.28 15.28 15.28 15.28 15.28

15.1315.13

15.28

15.28

0.1s 0.150.15 15.13

.O O O .0,0 1$:28


DCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315 0.315 28*0 0 2

XYZMES

377

(-121*3

(-1

21*3

(-1

21*3

(-1

0

SH ! H3 - north assembly

0.0 15.514 17.954 33.468

0.0 15.514 17.954 33.468 35.908 51.422 53.862 69.376

0.0 15.514 17.954 33.468 35.908 51.422 53.862 69.376

3 -1 3 3 3)*3 -1 3 -1

3 -1 3 3 3)*3 -1 3 -1

3 -1 3 3 3)*3 -1 3 -1

I II 1I

I:!Ii

4

3 -1 3 3 3)*2 -1 3 -1 -4 3 -4 4 3 4



PLATE ! H4 - filler/half--moderator Y- segment0 1 0 1 1.23 4 3

END*************************************** ,******************************************

BEGIN CONTROL DATASTAGES -1 100 1000 STDV 0.0014END*************************************** ****************************************

BEGIN SOURCE GEOMETRYZONEMAT ZONE 1 PART 4 / MATERIAL 1END

BEGIN ENERGY DATA

SCORING GROUPS 1615.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-51.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.08

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.08*…----------------------------------------------



* Fissile Material: Low enriched Uranium oxide powder* Geometry: Homogeneous blocks in aluminium cans* Moderator: Plastic* Neutron poison: None* Reflector: Plastic* Reference: R E Rothe, I Oh and G R Goebel* Critical Experiments with Intersitially-Moderated* Arrays of Low-enriched Uranium Oxide* NUREG/CR-1071

* September 1980

* Critical Parameter Data*…-- - -- - -- -- - -- - - - - -- --

* Experiment 8 - Category M (Mild steel absorber)* Configuration (k)* Number of cans = 62

* Critical separation of north and south cores - 1.28cm

* Important Notes*…--- ----- --- --

* 1. Polythene bags assumed homogeneously mixed with powder* 2. Average block composition data used* 3. Powder impurities ignored* 4. Miscellaneous tapes ignored* 5. Curved can edges represented as square* 6. Average plastic composition used* 7. Filler percentage used to scale dersity (88%)* 8. Average inner and outer reflector dimensions used* 9. Exact fitting abosrber plates '****************************************** *********************** *-* *************


WGT 4.60 Ml - uranium oxide powderU234 3.8 U235 568.6 U236 10.2 U238 12165.4O 2619.5 J2H/H20 42.5 C 45






WGT 1.261 M5 - reflector plastic

J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P231 0.82 CL 1.45 J2RU101 5.68

WGT 7.93 ! M6 - steel table top

CR 19.7 NI 10.3 FE 70.0


FE 99.595 C 0.065 MN 0.34

END


PART

BOXBOX

BOXBOX

1 NEST

BH3M4

M5

M3


0.0 0.0 0.0 33.4613 69.376 69.376

-5.402 0.0 -10.1 38.871) 77.5 83.4

-30.602 -25.6 -35.45 64.07 128.4 133.6-30.602 -25.6 -35.45 65.3 L28.4 133.6

PART

BOXBOX

BOXBOX

PART

BOXBOX

BOX

PART

BOX

BOX

2 NESTBH5

M4

MSM3


0.0 0.0 0.0 33.4613 69.376 69.3760.0 0.0 -10.1 46.77 77.5 83.4

0.0 -25.6 -35.45 73.27 128.4 133.6-1.23 -25.6 -35.45 74.5 :L28.4 133.6

3 CLUSTER !

P1 0.0 0.0 0.0P2 66.58 0.0 0.0

MO 0.0 0.0 0.0

Complete assembly

65.3 128.4 133.6

74.5 128.4 133.6141.08 128.4 133.6

Add steel table top

141.08 128.4 133.6

141.08 128.4 134.9

4 NEST

P3

M6

0.0 0.0 0.0

0.0 0.0 -1.3

END

BEGIN HOLE DATA

POLY ! H1 - aluminium can and contents plus steel surround

ORIGIN 0.117 0.117 0.117

2 7

1 8 0.15 0.15 0.150.15 0.15 15.13

-2 8 0.0 0.0 0.00.0 0.0 15.28

0.15 15.13 0.15 15.13 15.13 0.15 15.13 0.15 0.150.15 15.13 15..3 15.13 15.13 15.13 15.13 0.15 15.13

0.0 15.28 0.0 15.28 15.28 0.0 15.28 0.0 0.0

0.0 15.28 15.28 15.28 15.28 15.28 15.28 0.0 15.28


DCOSINES -1 0 0 0 0 17 4 RECT 2.18 3.82-1.09 -1.91 PINS 0.315 0.315 28*0 0 *

XYZMESH3 0.0 15.514 17.7 0.0 15.514 17.,

7 0.0 15.514 17.1

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*2

0


954 33.468

954 33.468 35.908 51.422

954 33.468 35.908 51.422

-1 3 -1

53.862 69.37653.862 69.376

-1 3 -1

-1 3 -1

-1 3 -1 -4 3 3 4 3 -1



PLATE ! H4 - filler/half-moderator Y- segment

0 1 0 1 1.23 4 3

XYZMESH ! H5 - south assembly3 0.0 15.514 17.954 33.4687 0.0 15.514 17.954 33.468 35.908 5L.422 53.862 69.376

7 0.0 15.514 17.954 33.468 35.908 5:L.422 53.862 69.376

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*2 -1 3 -1 3 3 -4 -1 3 4

0

END* * ************************************ **,******** ********************************

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END* * *** * *** * ********************* ******** .****************** *** ** * **** * ** ** ** ** ** *



END*************************************** *****************************************

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.09

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.09*…----------------------------------------------

* Calculations performed by N R Smith - October 1995

* Reported in ANSWERS/MONK/VAL/25


* Fissile Material: Low enriched Uranium oxide powder

* Geometry: Homogeneous blocks in aluminium cans

* Moderator: Plastic

* Neutron poison: None

* Reflector: Plastic

* Reference: R E Rothe, I Oh and G R Goebel

* Critical Experiments with Intersitially-Moderated

* Arrays of Low-enriched Uranium Oxide

* NUREG/CR-1071

* September 1980

* Critical Parameter Data*…-- - -- - -- - -- - - -- - -- - --

* Experiment 9 - Category m (Thin mild Steel absorber)

* Configuration (d)



* Important Notes*…-------------

* 1. Polythene bags assumed homogeneously mixed with powder

* 2. Average block composition data used

* 3. Powder impurities ignored

* 4. Miscellaneous tapes ignored

* 5. Curved can edges represented as square

* 6. Average plastic composition used* 7. Filler percentage used to scale dersity (86%)

* 8. Average inner and outer reflector dimensions used

* 9. Exact fitting abosrber plates****** * ********************************i*** ****************************** *********

BEGIN MATERIAL DATA

MONK

7 19 NUCNAMES

WGT 4.60 Ml - uranium oxide powder

U234 3.8 U235 568.6 U236 10.2 U238 12165.4

O 2619.5 J2H/H20 42.5 C 45


AL27 99.36 SI 0.10 FE 0.42 CU 0.12

WGT 1.185 ! M3 - moderator plastic

J2H/CH2 7.83 C 59.49 0 32.48


J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

Reference: ANSWERS/MONKNVAL. 1/25Page: 51



WGT 7.93 !M6 - steel table topCR 19.7 NI 10.3 FE 70.0

WGT 7.863 M7 - thin steel absorberFE 99.636 C 0.034 MN 0.33

END*********************************I******,****************************************


PART

BOX

BOXBOX

BOX

1 NEST

BH3M4M5

M3


0.0 0.0 0.0 33.24 68.92 68.92-5.63 0.0 -10.1 38.870 77.5 83.4-30.83 -25.6 -35.45 64.07 128.4 133.6-30.83 -25.6 -35.45 65.3 128.4 133.6

PARTBOX

BOXBOX

BOX

2 NESTBH9

M4

M5

M3

! South core assembly0.0 0.0 0.0 33.24 68.92 68.92

0.0 0.0 -10.1 46.67 77.5 83.40.0 -25.6 -35.45 73.27 128.4 133.6-1.23 -25.6 -35.45 74.5 128.4 133.6

PART 3 CLUSTER

BOX P1 0.0 0.0 0.0

BOX P2 65.54 0.0 0.0BOX MO 0.0 0.0 0.0

Complete assembly65.3 128.4 133.6

74.5 128.4 133.6

140.04 128.4 133.6

Add steel table top

140.04 128.4 133.6

140.04 128.4 134.9

PART

BOXBOX

4 NEST

P3M6

0.0 0.0 0.00.0 0.0 -1.3

END**************************** **** ******** ************************************ *****

BEGIN HOLE DATA

POLY ! H:

ORIGIN 0.060 0.060 0.060

2 7

1 8 0.15 0.15 0.15 00.15 0.15 15.13 0.

-2 8 0.0 0.0 0.0 0.0.0 0.0 15.28 0.

1 - aluminium can and contents plus steel surround

.15 15.13 0.15

.15 15.13 15.13

.0 15.28 0.0

.0 15.28 15.28

15.13 15.13 0.1515.13 15.13 15.13

15,28 15.28 0.015.28 15.28 15.28

15.13 0.15 0.1515.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

LATTICE

DCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.31

! H2 - holes in can body

5 0.315 28*0 0 2

XYZMESH

3 0.0 15.400 17.:7 0.0 15.400 17.:7 0.0 15.400 17.:

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3

21*3

(-1 3 -1 3 3 3)*3


840 33.240

840 33.240 35.680 51.080

840 33.240 35.680 51.080

-1 3 -1

53.520 68.920

53.520 68.920

-1 3 -1

-1 3 -1

-4 3 -4 (-4 3 3)*5 -4 3 -4

3*4 4 -7 -7 4 -5 -1 4 -5 3 4 -5 -1 4 -8 -8 3*4

0


Version: IAuthor: N R Suith

PLATE ! H4 - Filler/half-moderator Z segment0 0 1 1 1.23 4 3

PLATE H5 - Filler/half-moderator X+ segment

1 0 0 1 1.21 3 4

PLATE H6 - Filler/ha~f-moderator X- segment

1 0 0 1 1.23 4 3

PLATE ! H7 - Filler/half-moderator Y+ segment

0 1 0 1 1.21 3 4

PLATE ! H8 - Filler/half-moderator Y- segment

0 1 0 1 1.23 4 3

XYZMESH ! H9 - south assembly

3 0.0 15.400 17.840 33.240

7 0.0 15.400 17.840 33.240 35.680 51.080 53.520 68.920

7 0.0 15.400 17.840 33.240 35.680 51.080 53.520 68.920

(-1 3 -1 3 3 3)*3 -1 3 -1

21*3

(-l 3 -1 3 3 3)*3 -1 3 -1

21*3

(-1 3 -1 3 3 3)*3 -1 3 -1

-4 3 -4 (3 3 -4)*3 (-4 3 -4)*3

3*4 -7 -7 4 -1 -6 4 -8 -8 4 9*4

0

END**************************************** ****************************************

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END**************************************** *******************************,*********



END

BEGIN ENERGY DATA

SCORING GROUPS 1615.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END



Case 25.10

* MONK VALIDATION CALCULATIONS - EXPERIMENT 25.10*…-- - - - - - - - - - - - - - - - - - - - - - - - - - -- - - - - - - ---- - - - - - - -



* Fissile Material: Low enriched Uranium oxide powder* Geometry: Homogeneous blocks in aluminium cans* Moderator: Plastic* Neutron poison: None* Reflector: Plastic* Reference: R E Rothe, I Oh and G R Goebel* Critical Experiments with Intersitially-Moderated* Arrays of Low-enriched Uranium Oxide* NUREG/CR-1071* September 1980

* Critical Parameter Data*…--- - - -- - - - - -- - -- -- - --

* Experiment 10 - Category T (Thick steel/thin moderator)* Configuration (q)* Number of cans = 100* Critical separation of north and south cores = 0.70cm

* Important Notes*…-- --------- --

* 1. Polythene bags assumed homogeneously mixed with powder* 2. Average block composition data used* 3. Powder impurities ignored* 4. Miscellaneous tapes ignored* 5. Curved can edges represented as square* 6. Average plastic composition used* 7. Filler percentage used to scale density (84%)* 8. Average inner and outer reflector dimensions used* 9. Exact fitting abosrber plates**************************************** ****************************************









J2H/CH2 7.30 C 53.50 N 0.13 0 30.34 P31 0.82 CL 1.45 J2RU101 5.68

WGT 7.93 ! M6 - steel table top

CR 19.7 NI 10.3 FE 70.0


FE 99.595 C 0.065 MN 0.34

END


PART

BOX

BOXBOXBOX

1 NEST

BH5

M4

M5

M3


0.0 0.0 0.0 32.250 65.746 82.490

-7.312 0.0 0.0 39.570 77.5 83.4-32.512 -25.6 -25.35 64.77 128.4 133.6

-32.512 -25.6 -25.35 66.0 :.28.4 133.6

PART

BOXBOXBOXBOX

2 NESTBH6

M4

M5

M3


0.0 0.0 0.0 49.002 65.746 82.4900.0 0.0 0.0 49.87 77.5 83.4

0.0 -25.6 -25.35 76.37 128.4 133.6

-1.23 -25.6 -25.35 77.6 ].28.4 133.6

PART 3 CLUSTER

BOX P1 0.0 0.0 0.0

BOX P2 66.7 0.0 0.0

BOX MO 0.0 0.0 0.0

Complete assembly

66.0 128.4 133.6

77.6 128.4 133.6

144.3 128.4 133.6

PART 4 NEST

BOX P3BOX M6


0.0 0.0 0.0 144.3 128.4 J.33.6

0.0 0.0 -1.3 144.3 128.4 134.9

END***************************************1D****************************************

BEGIN HOLE DATA

POLY

ORIGIN 0.117 0.117 0.11

2 7

1 8 0.15 0.15 0.150.15 0.15 15.13

-2 8 0.0 0.0 0.0

0.0 0.0 15.28

Hl - aluminium can and contents plus steel surround

0.15 15.13 0.15 15.130.15 15.13 15.13 15.13

0.0 15.28 0.0 15.28

0.0 15.28 15.26 15.28

15.13 0.1515.13 15.13

15.28 0.0

15.28 15.28

15.13 0.15 0.1515.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28


DCOSINES -1 0 0 0 0 1

7 4 RECT 2.18 3.82

-1.09 -1.91 PINS 0.315 0.315 28*0 0 2

POLY ! H3 - aluminium can and contents plus steel surround

missing steel plates in X+ direction

ORIGIN 0.117 0.117 0.117

3 0

1 8 0.15 0.15 0.15 0.15 15.13 0.15 15.13 15.13 0.15 15.13 0.15 0.:

0.15 0.15 15.13 0.15 15.13 15.13 15.13 15.13 15.13 15.13 0.15 15

-2 8 0.0 0.0 0.0 0.0 15.28 0.0 15.28 15.28 0.0 15.28 0.0 0.0

0.0 0.0 15.28 0.0 15.28 15.2E 15.28 15.28 15.28 15.28 0.0 15.

7 8 -0.117 -0.117 -0.117 -0.117 15.397 -0.117 15.280 15.397 -0.117

15.280 -0.117 -0.117

-0.117 -0.117 15.397 -0.117 15.397 15.397 15.280 15.397 15.397

15.280 -0.117 15.397

.13

Reference: ANSWERS/MONKIVAL.1/25Page: 55


POLY ! H'

ORIGIN 0.117 0.117 0.117

3 0

1 8 0.15 0.15 0.15 0.

0.15 0.15 15.13 0.

-2 8 0.0 0.0 0.0 0.

0.0 0.0 15.28 0.

I - aluminium can and contents plus steel surroundmissingsteel plates in X- direction

7 8 0.0

15. 397

0.0

15. 397

-0.117

-0.117

-0.117

-0.117

-0.11

15.3915.35

.15 15.13 0.15

.15 15.13 15.13

.0 15.28 0.0

.0 15.28 15.28

L7 0.0 15.:

L7

17 0.0 15.:

197

15.13 15.1315.13 15.13

15.28 15.28

15.28 15.28

397 -0.117

0.15

15.13

0.0

15.28

15.397

15.13 0.15 0.15

15.13 0.15 15.13

15.28 0.0 0.0

15.28 0.0 15.28

15.397 -0.117

397 15.397 15.397 15.397 15.397

XYZMESH !H5 - north assembly3 0.0 15.514 16.744 32.258

7 0.0 15.514 16.744 32.258 33.488 49.002

9 0.0 15.514 16.744 32.258 33.488 49.002

(-1 3 -3 3 3 3)*3 -1 3 -3

21*3

(-1 3 -3 3 3 3)*3 -1 3 -3

21*3

(-1 3 -3 3 3 3)*3 -1 3 -3

21*3

(-1 3 -3 3 3 3)*3 -1 3 -3

21*3

(-1 3 -3 3 3 3)*3 -1 3 -3

0

50.232 65.74650.232 65.746 66.976 82.490

XYZMESH

5 0.0 15.514

7 0.0 15.514

9 0.0 15.514

(-4 3 -1 3 -1

35*3

(-4 3 -1 3 -1

35*3

(-4 3 -1 3 -1

35*3

(-4 3 -1 3 -1

35*3

(-4 3 -1 3 -10

! H6 - south assembly16.744 32.258 33.488 49.002

16.744 32.258 33.488 49.002 50.232 65.746

16.744 32.258 33.488 49.002 50.232 65.746 66.976 82.490

3 3 3 3 3)*3 -4 3 -1 3 -1

3 3 3 3 3)*3

3 3 3 3 3)*3

3 3 3 3 3)*3

3 3 3 3 3)*3

-4 3 -1 3 -1

-4 3 -1 3 -1

-4 3 -1 3 -1

-4 3 -1 3 -1

END

BEGIN CONTROL DATA

STAGES -1 100 1000 STDV 0.0014

END



END

BEGIN ENERGY DATA

SCORING GROUPS 16

15.0 3.0 1.4 0.9 0.4 0.1 1.7E-2 3.OE-3 5.5E-4 1.OE-4 3.OE-5

1.OE-5 3.OE-6 1.OE-6 4.OE-7 1.OE-7 1.OE-20

END

Documents

MONK Validation Report No. 25. - NRC: Home Page · ANSWERS/MONK/VAL. 1/25 1 October 1996 NRSmith MONK VALIDATION REPORT NO. 25 N R Smith AEA Technology Summary This report describes