ML19261C987
| ML19261C987 | |
| Person / Time | |
|---|---|
| Site: | 07105908 |
| Issue date: | 05/08/1973 |
| From: | Owens G WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP. |
| To: | Reese W US ATOMIC ENERGY COMMISSION (AEC) |
| Shared Package | |
| ML19261C983 | List: |
| References | |
| WAPD-RS(CC)-620, NUDOCS 7904230102 | |
| Download: ML19261C987 (13) | |
Text
y tuJD-RS(CC)-620 m.
b I
cett:sAtzxece(men Tilfif,llouSf Electt!c Corporation 0003 1
WestIA!!'nPerrsyhna15122 s
May '8, 1973 i
Manar.cr, Pittchm rJh Haval Reactors Office United States Atomic Energy Ccenmi. scion Post Officc Bccc,109 West l'ifflin, PennJ1vania 15122 Attention: Mr. U. A. Recce, Director Safety and !!aterials Division
Subject:
Request for Arproval to Ircrease H/U limit for DOP S}<:cification 6M Dmm
Reference:
(a) WAPD-RS(CC)-lll, "Benchnark Calculations for 2330 and 232Th Isetopes on Tape Humbers 7627 and 1706 Used in the Hazard Aralysis for the INilR Program," dated April 1972 SC-DR-72 0397, "Special Tests for Plutonium (b)
Shipping Containers 6M, $793,and L-10" Se;tember 1972 L. F. Stravaamik, Sandia laboratories (c) DP-1292, "Driet and Poard-Type II. alation Overrocks of Shippin,r; Packages fcr Radioactive Materials,"
E. E. Imra]len, Savannah River Iaboratcry Ju]y 1972 (d) UAID-SG(Fil)-35$ 3 "BFIGC Meetiry; of April 23, 1969" WAPD-0(AO) 14191, " Westinghouse Bettic Atomic Pcr<rcr (c)
Intx>ratory Radicoctive ard Fissionablo Paterial Shipping Containersy Section 5B May 1967 (f) NR:DP:RS Drodsky A//2002 dated December 21, 1967 Daar Sir:
Dettic plana to ship binary (Th02 uith up to 6 v/o 233UO ) gel:rler cludge 2
Ct:rrent a retrievabic burial site using D02 Specification oM Drum.
0CFR 170-189) remit cach drum to contain 50] grans 233U to DOP rer3ulations (It but restrict the hydrogen content Ly liriti ng the H/U ratio to a narime:.1 Dinarf sludr.c can be dried to this limit but, since the mterial is of 3.
inherently hygroscopic vill rapidly absc-b :noisture from the strrounding The racunL of such moisture is typically on the order of 1 u/o.
For air.
binary ratorial of the composition being produced at Bcttis, this is egriv-alent to an H/U ratio of up to 20. Ecttis therefere propcces to increase from the procent value of
- the allouable.H/U limit for shire:cnt of 233UO 2
's,3 to a new liH t of 20.
1 WAFD-RS(CC ).l>20 i
t of Page 2 the DOP regulatiom for ship::enraterials t-Sirce the 6M drum is approved inlarge quantity and f t
ncet the stnictural require.cn sit is therefore s t ate within the evaluated ard shcun tosatisfaction of DCT.
s in 6M drums is nuclearly safed Appeniix 0529 of 233UO2 b
to the that the shirnent ofof h9CFR 173 and of Chapter an ith an H/U ratio not to' exceed 20.
233U The criteria amlysis was Bettis plans to make shirnents o 233U), but the not, nore than $00 grams 23 U w terial (< 6u/o limit nay le applied to any 3
/
All shipments will be in the form of binary ma2 so that the increased H U i e shipment in 6M druns.This is more re DOP 233UO b
of higher v/o mixtures that might mqu r performed for
)(2)(i)), which pomit an unlinited nu~. erHc III.
will be made as Fissile Clans ile Class I.
adiation 3nvols regulatiom (h9CFR 173 396 (csuch drums to be shipp i
Class reduct, ion in the number 233U is the limitin.3requirenents of O$29 for Fiss factor.
associated uith theon tin basis of the was therefdre dom i
nts -
in 0$29 for Fissile Class III sh pne i ting of III shipments.
be suberitical, 2) an array cons s3) an array There are three basic requirements t incra must In suberitien1 andt of d
- 1) each individual container must suberitical.
tuo shipments of undamged con a 233g consisting of a single chiluen t d on the basis that the total itical The firct condition nay be demonstra e(500 grarc) is less The mird-The i
mass in the inner 2R contairer 233U in TID-7028.
233U vi]1 be less than 6 w/o in thcr a mss of $90 grams quoted for icantly rarcater since themum critien1 mass for a 6 w o m denomtrated utdng the Ecttis Monteof the n
/
statistical entinate multiplication s The second anl thini conditions wereCarle progra:n R The uncertainties quoted here for theT y were blens as a cat' ton of a given systcm.are at the 96% confiderce level.
The 6M dntm was shsun in %e ECP proThe t
qualified in Reference (a).
le h0 pipe uith 1/h inch thick caps a hich.
23 inch diarct.cr cylinder 35 inches of the 2R containtr is 7 9 liters.
is a 2h inch section of $ inch ccheduThe total en in the drun by eclo tex, a sugar caneCe The pipe is centered ard suppcrtedfiber mterini co equivalent to water at 11% of either end.
f cellulecc.
d to represcrt celo-tex in the RCP This is containing 6% by weight of hydrogen.the 1.heoretica problems.
_.m G
Page 3
}JAPD-RS(CC) -620 In order to show that the array of tuo shipmats of undanaged contairers is subcritical, it was simplest to demonstrate that an infinite array of such containers is subcritical. Using the syr.ctry capabilities of RCP, a 1/3 section of a single drun uas shown, resulting in the equivalcat of an infinite hexanguhr array of 6M dnuts. Each drum was 7
shown with $00 grams 233U trith sufficient hydrogrm to obtain an H/U ratio of 20 The uranim and the hydrogen were assumd to be unifomly distri-buted throughout the containment vessel. Tic celo-tex was ircluded, and the spaces between the drums were filled with air. The remiting nulti-plication for this case as calculated by RCP is 0.h8 i.0$ which is well subcritic al.
It is noted that the same problem with an H/U of 3 results in a nultiplication of 0.$01.03, iniicating that ircreasing the H/U limit to 20.,has no significant effect on an arrtr/ of this size.
A finite hexangular array or$7 drums was used to demonstrate the suberiticality of the array of damaged drums.
An array of $7 drums was used rather than the actual shipment limit of $1 drums in order to simplify the RCP representation, which is shown in Figure 1.
It was postulated that the damage to the druns consisted of crushing the drun to an eqtd. valent dianeter of 16 inches, cc:plete charrire, of the celo-tex (ani consequent loss of all hydrogen) during the fire test and flooding of the 2R container with water.
The crushing estimte was a conservative extrapolation of data from Refereme (b), uhich presents results obtaired by Sardia dtring tests on the 6M drums ard other containers. Crushing as great as six inches was observed after impacts on the edge of the lid at 130 feet per second.
It' is estimated that this is equivalent to a unifcrm decrease in radius of mt nore than 3 inches along the entire height of the drum. Accordingly, the damaged drums were assumed to be on a 16 inch center-to-center spacing.
As sho.m in the same document and also in Reference (c), much of the celo-tex is charred during the required fire test. It is conservatively assumed that all the celo-tex is charred an1 consequently loses all its original hydrogen content. This in sinnificant sime the hydrogen provides conc isolation be-tueen iniividual 6M drums by reducing the neutron interaction.
Complete flooding of the 2R container in the danaged 6M druro in the array is also considered. This argumption is necessarv since, in Bettis exparience, it is difficult to produce a leak tight seal on the schedule ho pipas as 2R conta iners, mking it passible for watcr to leak into the pipas under accide'$
c onditions. This is conservatively taken into account by assuming that all the pi es are completely flood ed'.
l The $7 drums were airangad in 3 layers of 19 drums. Each layer formed a hex-at;on uith the 19 drums m a 16" trianrular pitch.
It was assired that due to the crushing accident, the charred celo-tex, re; resented by a void, filled the entire space bett.uen the schedule h0 pires.
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D
Page h UAPD-R3(CC) 620 The nultiplication of the da: raged array, as calcuhted by RCP, is 0.91.1.03.
The sane array with the colo-. tex present has a multip'licatica of 0.77 i.02.
Thus fe anall arrays, the presence or absence of tho celo-tex is not crucial.
Ilo.rever, it can be shoun that loss of the colo-tex in inifinite arrays can result in a nultiplication significantly greater than unity. A few additional problems were run for the finite $7 drum array to imure tint them is not an u
amount of interspersed moleration tint would msult in a hider multiplication.
The results of these problens, p esented in Fi~are 2, chcw that there is no observabic naxinum in nultiplication between 0,% water (charred celo-tex) and 1]$ water (virr;in eclo-tex).
It is coneltded on the basin of these calcuhtions that the proposed ship 7ent is in co7pliance with tln requiremmts of chapter O$29. This compliance is demon:3trated item-by-iten in the accompanying Tabh I.
s..
Fissile Chsc III ship ents of 5 6M drums with $0] grams of unmoderated 233g each was approved by the Bottis Fuel Hartiling Safeguards Condtt ce in Reference (d). Approval uns based on the justification cf similar shipmnts with 1503 seems 235U per drun as presented in Reference (c), uhich was appro7ed by t!c AEC in Reference (f). The ace.ident conditions as comidered by Bettis are the same fe 500 grams 233U at cn H/U ratio of 20 as at an H/U ratio of 3 since total flooding of the 2R container is assumed. The accident coalitions were censidered in Refereme (c) but were reconsidemd in this letter for infcr-nation arrl conphtenass. It is further noted that DT Special Femit $3h1 permitted a simihr increase in the H/U ratio for shipments of 235U in 6M drums provided that the 233U content did rot exceed 3.6 kilograrc.
Al'C approval is requested on this basis to ship $16M drums wi.th $00 grams 2330 por drum at a H/U ratio not to excced 20.
Very truly yours, b /
W gbQ* Ava l'
/. C. Owens, Ihnager G
Criticality Control Radiation and Safety L. Laude /jnl 7
Attachnents 9
WAID-RS(CC)-620 3-
.u-L Black AbsorberNJ 12". Water Reflector e-O O
2R Container Charred Ce10-tex D
D
_l I
w Syr ctry Boundary Conditions L'
FICURE 1 RCP Reprer.c'.
t.ien of the Array of $7 @! Druns O
n ---
i, i
T
- o. 65 U
O S
6 Or.80 0
n O
M 8075 c
O bg
.a 0 70 0
5 10 20 25 Equivnicct % Water Botueen Pipes FIGURE 2 Effect of Intersterced Moderation on Array Midtiinicdion V"'
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s T.GIZ I-CNFLIA?tE TO THE ?F;CLE/R SAET R20"IREG??:'S CF /JPZ'DII 0528 cf the AE0 ?*J2FJAI, Section of Roqtdrement or Subject Cha ?.,cr 0529 of Provision
,Ascccanent of Cc.e.pli.,nce C.
Critic.111ty S tan t'ar ds for Finnile Ma.terial The nTinal contents of the package is less thr.n PC CI'"'
the nint:t:1 critical mass fct, 233U.
1 A package used for the transport of fissile catorial shall be so designed and censtrucqcd and its contents so limited that it would be suberitical if it is tsr u:a.:4 that water leaks into the contain-ent vessel, and:
a.
water coderation of the contants occurs to tin most reactive credible er. tent consistent with the chemical cud physical form of the centents; and b,
the contain=ent vessel is fully reficcted on all sides by water.
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2 k'AFS-25(CO),520 2
A package used for the transport of' fissile This pragraph is rot applicable cir.ce this materici shall be so designed and con-container will not be used by Ecttis to ship structed and its contents so limited that liquid s.
't would ic suberitical if it is assumed that any contents of the package which are liquid during norcal transport leak out of the containment vessel, and that the fissile material is then:
~.
a.
in the rest rdactive credible configuration consistent with the chemica7 an'd physical form of the material; f
b.
moderated by water outside of the containment vessel to the most reactive credible extent; and c.
fully reflected on all sides by water.
3.
The rnnager or other designated official No exemptions to the roquirencris of Section II.C.
may approve exceptions to the requirements are irquested.
of this section where the containment vessel incorporates special design features which would preclude Icakage of liquids in spite of any single packaging ciror and appropriate measures are taken bufore cach shipment to verify the leak tightness of each conteinment vessel.
i
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St:ndaron for Noren1 Conditions of Trans-port fc a SL: zle Packace 2
A package used for the shipment of fissile
=aterial shall be so c'esigned and. cen-structed and its contents so limited that under normal conditions of transport, s pe ci fie d ' in annex 1, below, considere d individually:
a, the package will be suberitical; Sec item II.C. abotc.
b.
the geo=ctric form of the package
. Satisfied by acceptance as a specification centents voul'd not be substantially c ontainer.
altered; 4
c.
there will be no leakage of water into In lea' cage of water will not ocer under the contain~.__nt vessel. This requirc-nomal conditions of transpcrt.
ment need not bcoct if, in the evaluation of undaraged packages under H l., I. l.a, or J.1.,
below, it has been assumed that moderation is present to such an extent a."
to cause maximum reactivity consistent with the chemical and physical form of the ratericl; cnd d.
there will be no substantial reduction Satisfied by acceptance as a specification containct in the effectiveness of the packaging, 9
9 8
9
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" f
-h-WAFD-ES(CC) 6?O F.
Standards for Evpo_thetien1 Accident
~
Cendittens f er.m Single Packnec_
2 A package used for the ship =ent of tissile
'The worst case condition of a singlo pnckage caterial shall be so designed and constructed after the hypothetical accidents re]ative to and its contents so limited that if subjected nuclear safe ty is 'le cane as that de-cribed.
to the hypothetical accident conditicas in II.O.; it is t.hcrefere concluded '.uat therc specified in annex 2, below, as the Free Drop, Puncture, Thermal, and Water In crsion conditions, is no problcm of nuclear safety for a single in the sequence listed in annex 2, the package container after the hypothetical ac'd/:tSts.
would be suberitical.
In determining whether this standard is satis fied, it shall be assu=cd that:
n.
the fissile enterial is in tbc cost reactive credible configuration consistent with the d maged condition of the package and the chemical and physical form of the contents; I
b.
water moderation curs to the most reactive credible extent consistent with the damaged condition of the package and the chemical and physical form of the contents; and
--n there is reflection by water en all c.
sides and as close as is consistent with the damaged condition of the package.
8 w
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u.
'G.
Evaluetten_of an Arrav of Packaces of Fissile Material 1
The ef fect of the transport environment en the nuclear criticality safety of an array of packages of fissile caterial shall be evaluated by subjecting a sampic package or a scale model, by test or other assessment, to the hypothetical accident conditions specified in *d.,
I.,
or J., below, for the proposed fissile class, and by assuming that cach pachage in the array is damaged to the cama extent a5 the sa=ple package or scale model.
In the case of a Fissile Class III shipment, the =anager or other designated official may, taking into account controls to be exercised by the shipper, permit the chipment to be evaluated as a whole rather than as individual packages, and cither with or without the transporting vehicle, for the purpose of one or more tests.
2 In detcrning whether the standards of 11.2.,
I. l.b., and J.2., belev, are satic fie d, it shall be assu=2d that:
a.
the fissile material is in the most The fissilo rntci.~.a1 was assunod to uniform 1v reactive credibic configuration distributed throughout the ccntainment vassch..
consistent with the damaged condition of the package, the chemical and physical form of the contents, an6 controls exercised over the nurber of packages to be transported together; cnd
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L_
b
?
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'JAFD-RS (CC'; 6EC b.
'.10er moderation occurs to the most Cetplete Water ncdcration of the contents reactive credible er. tent censistent vith the dac:ged condition of the was assuncd.
package and the chenical and physical form of the contents.
H.
_ Specific Standards for a Fiscile Class I
_Pa cbq Not app'licabic.
I.
Seceific Se7ndards for a Fissile _Cinns II Pncb ce Not applicable.
J.
Seccific Standards __for a Fiesile-Claes III Shiprent A package for Fissile Clacs III ship =ent shall be so decigned and constructed and its contents co limited, and the number of pac kage in a Fissile Class III shipnent chall be so limited that:
1 the undamaged chipment would be sub-An infinite array Ma nced containers critical with an identical ship =ent rather. than only two shipnents, was considered'.-
in contact with it and with the two ship =cate cloccly re flected on all The multiplication was shown to be 0.h6 I.05.
sidcc by water; and 4
s 2
the ship =ent would be suberiticci if each The danaged array was chem to be cube:'U. cal package were subjected to the
. g }. a multiplication of 0.811.03 The h re thetical o
hypctheticar acetdent conditions specified 4
acc_c, erd, co.h,g ons in Armex 2 vere used, in annex 2, belew, as the ree Drc,;,
c Thercel, and Water Immersion conditions, in the sequence listed in annex 2, with close re flection by water en all sides of the array and with the packages in the most reactive arrangement and with the most reactive degree of interspersed hydrogenous coderation which would be credible considering the controls to be exercised ever the. shipment. The condition of the pa'ckage shell be assumed to be as described in G., above.
Hypothetical accident conditions different from those specified in this subparagraph may be approved by the manager or other designated of ficial if the controls proposed to bc exerciced by the shipper arc demonstrated to be adequate to assure the safety of the shipment.
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