Annual Report to Congress 1966 Plowshare 453700

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7&-___ ~ ~ __- iawrence Radirtfion L a b o r a f o w yi . U N I V E R S I T Y O F C A L I F O R N I A

ONGRESS - 1966(Title: Unclassified)Plowshare Division

October 31, 1 9 6 6

DISCLAIMERThis report was prepared as an account of work sponsored by an agency of th e United Sta tesGovernment. Neithe r the United Sta tes Government nor any agency thereof, nor any of theiremployees, makes any warranty, express or implied, or assumes any legal liability or responsi-bility for the accuracj, completeness, or usefulness of any information, apparatus, produb, orprocess disclosed, or represents that its use would not infringe privately owned rights. Refer-ence herein to any specific commercial product, process, or service by trade name, trademark,manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recom-mendation, or favoring by the United States Government or any agency thereof. The viewsand opinions of authors expressed herein do not necessarily state or reflect those of theUnited States Government or any agency thereof.

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ANNUAL REPORT TO CONGRESS - 1966Plowshare ivision

Lawre nce Radiation Laboratory, University of California,Livermore, California

I. INTRODUCTIONPr og re ss in the Plowshare program during 1966 was characterized by the

upsurgence of i n t e r p t by industry in the contained applications of nuclear explosionsfor gas and oil stimulation, stora ge and disposal, rec ov ery of oil fr om oil shales, and

' mining. Advances in the excavation are a wer e limited to improved code calculationsa s no field expe riments wer e conducted.

11. NATURAL RESOURCES DEVELOPMENTA. Gas and Oil Stimulation

1. General SummaryNatural gas is produced c omm erci ally fro m underground regions of permeable

rock in which the ga s ha s been trapped.the ga s normally flows fre el y into the well fro m the pore s in the rock.can drain t he gas f rom a lar ge volume of reserv oi r rock at a ra te fast enough to be

When a well is dri lled into the r es er vo ir rock,A single well

e conomicai ly worthwhile.In many ar e as in the weste rn United States and Canada, however, natu ral gas is

found i n reserv oi r rock of such low permeabili ty that it cannot be produced economicallyf rom normal xell. The trapped gas, i f it f lows at all, does not f low freely enough into._the well to give an ecoiiomically attractive rate of production.be used xo stim ulate produc tion of g a s from such tight re servo irs.method (Fig. l , nuclear explosions in the res erv oir rock a re used to cr eat e large zones

Nuclear explosions canIn the proposed

WLC: &&,*


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("chimneys") of broken and c rack ed ro ck into which the ga s would flow more freely.The chimney essentially becomes a ve ry la rg e production well.

A survey of more' than 125 members of the natural gas producing industryindicated 23 gas fields in t he United States and 9 in Canada where production pro blem sa r e attributed to low permeabili ty of the gas-bearing strata.

Figure 2shows the known gas-bearing reservoirs in the Rocky Mountain stateswith production zones thick enough to warrant consideration for nuclear stimulation.Other suitable a re as f or nuclea r stimulation a r e in Western Canada, and in parts ofKansas, Oklahoma, and Texas. The nuc lea r stimulation technique will have its firstte st i n Pro jec t Gasbuggy (described below); i f this test and others show the techniqueto be feasible, our natura l gas rese rve s will be increased great ly - erhaps by tentimes the ir present .amount.i

2. Planned Gasbuggy Experim entProject Gasbuggy is a nuclear stimulation experiment planned for a remote portion

of the San Juan Basin in New Mexico, about 70 miles east of Farmington. The presentplan is to detonate a 24-kiloton nuclear device at a depth of 4200 feet, which is slightlybelow the Pictured Cliffs Formation, a gas -bearing res erv oir of low permeability about300 feet thick at the site of the experiment. El Pa so Natural Gas Company and the U. S.Bure au of M ines will part icipa te in the Gasbuggy experim ent; the Law renc e RadiationLaborator y (LRL) will furniqh technica l direction.

The experiment a s presen tly conceived is a com prehensive investigation of theeffects that a nuclear explosion in a low-permeabili ty re se rv oir wi l l have on gasproduction. Becau se Gasbuggy is a fracture-controlled re serv oir, a l l questionspertaining to other types of re se rv oir s cannot be answered by this single experiment.

The Gasbuggy experim ent wil l permit investigation of two ma jor a re a s: (1) changesi n the r e se rvo i r rock as a re su lt of the explosion, and (2) contamination of the gas byradioactive products of the explosion and the efficacy of proposed control me asu res .

a Effects of Explosion on Reservoir Rock - Before the shot, the res er vo ir rockwill be explored by core dril l ing at various distances and directions f ro m the planned


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shot location. This core-drilling information will be supplemented by 1) extensivetes ts on core sam ples and 2) a comprehensive geophysical and hydrological loggingprogram.instru men ts fo r mea surin g the effects of the shot.

Some of the dr il l holes fo r the preshot exploration will be used to emplace

The amount of ga s in place, its distribution, and the perm eabi lity of the formationwill be determined by a se ri es of r es er vo ir production tes ts to which both s tanda rd andtime-dependent computer analysis techniques will be applied.

Characteris t ics of the rese rvo ir after the shot will be determined by a postshotdrilling program.will be taken t o study the changes that have occurred .the data taken at the tim e of the shot, will make possible an improved definition of t hefracturing m ech ani shs and the ir effect iveness in increasing permeabi l i ty of t heres erv oir rock. Gas production tests and analysis s im ilar to those performed preshotwi l l estab lish the productivity change brought about by the nu clea r stimulation.

The boundaries of the chimne y will be delineated, and rock samplesThis information, together with

b. Effects of Radioactive Contamination of the Gas - After 6 to 1 2 months, thesho rt -lived radioactive isotopes will have decayed, leaving krypton -85 and tri tiu m(hydrogen-3) a s the principal radioactive contaminants in the gas.noble o r unreactive gas) wil l have been produced almost en tirely by th e fission reaction .

Krypton (which is a

Tritium, on the other hand, is a product of the fusion reacti on; it can be eliminatedfr om the detonation products by choosing an all-f issio n device (which, of cou rse , wouldincrease the krypton production).explosives that could be used in future applications.

Such a choice might place se ve re limitation s on the

It may develop that the trit ium is pri ma rily contained in water vap or which couldthen be removed at the well head. Another possibility is to develop techniques fo rflushing the gas at the well head to remov e su bstantial amount of both tri ti um and krypton.

nuclear explosive will he selected to allow investigation of both the fissio n and fusionreactions in the hydrocarbons.


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1. General SummaryB. Storage and Disposal

Increasing use of natural gas has brought a demand for more s torag e capaci tythan can be m et by conventional storage rese rvoir s, such a s depleted na tural g as fields.Present indications are that the demand for g as stora ge capacity will grow by at l e a s t177 billion cubic feet p er ye ar (see Fig. 3).stor age capaci ty is to produce large underground cav ities by nuc lea r explosions.

One promising method for creat ing new

A feasibili ty study ha s shown that a nuclear-explosion-produced c himney (seeFig. 4 could provide sto rag e fo r up to 10 million cubic feet of g a s per kiloton ofexplosive yield.at the chimney' s d&th below the surf ace .be possible, the reb y providing even gre ate r stora ge capacity.

This assumes a gas s torage pre ssu re equal to hydros ta tic pre ssur eConsiderably higher pr es su re s than this may

A nuc lea r chimney can be made to yield its storage gas ov er a v e r y wide ra ng e ofCalculations made f or flow r a t e s f r o mlow r a te s with essenti ally the sa m e equipment.

1 million to 500 million cubic feet per day from a chimney produced by a 50-kilotonexplosion indicate that investment costs would be f ro m $2 t o 4 pe r thousand cubic feetof usable gas sto ra ge capacity.ga s storag e in depleted gas, oil , or aquifer reserv oirs, and two to ten ti me s cheaperthan other standard storage methods.

These numbers a r e competit ive with natu ral underground

2. Proposed Ketch ExperimentThe feasibility of storing natural gas in a nuclear chimney will be tested in the

Ketch prototype experim ent, which has been proposed by the Columbia Gas S ystemService Corporation a s the result of a joint design effort with LRL.

A s i t e in cen tral Pennsylvania has been selected fo r Proje ct Ketch, in which a24-kiloton nuclear explosive set off at a depth of 3300 feet in an impermeable shale isexpected t o produce a chimney with a stora ge volume gr ea te r than 2 million cubic feet.The experiment wi l l have three main purposes:

(1) To de ter mi ne the ability of a rubble-filled chimney in a relativelyimpermeable material to s to r e gas at pres su res up to and abovehydrostatic p r e s s u r e .


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(2) To determine the total volume available fo r storage, includingthe frac tion ou tside the chimney boundaries.

3) To determine the feasibili ty and necessity f or various methodsof flushing and controlling the gase ous r adioactivity prese nt inthe chimney.

C. Oil Shales1. General Summary

A recent theoretical study at LRL has examined the problem of retorting brokenoil shale in a chimney created by an underground nuclear explosion,base d on previously developed predictions of the probable siz e distribution of oi l shalefragments in a chimney. Results of the study suggest that a lmos t al l the oil, includingthat in oil shale chunks as la rg e as seve ral feet acro ss, can be removed by retortingslowly at tem pera tures in the range of 750 F, considerably lower than thos e used inmost previously suggested retorting schemes.

Calculations were

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The proposed nuclear chimney retorting syste m uses comparatively low air flowrates, thus keeping compressor costs at a lowe r level. Twelve to eighteen monthswould be required to reto rt completely the broken oil shale in a 100-kiloton nuclearchimney (Fig. 5). It should be possible to re cov er 50 to 70 percent of the oil in thebroken shale.

Results of the theoretical study ar e in excellent agreemen t with experimentsconducted by the U. S. Bureau of Mines (USBM), in which fragm ents of oil sha le up to20 inches acros s were retorted in a 6-foot diam eter , 10-foot high ve sse l.and experimeptal re sul ts a re presented in a recent joint technical report by L R L andUSBM.

Calculations

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It is estimated that Colorado's Piceance Basin contains 320 bil lion barr els of oili n oil shale formations 5 feet o r more thick, with an ave rage oil content of 2 5 gallons

%L omb ard, David B., and 13. C. Carpen ter. Retorting Oil Shale in a Nuclear Chimney,UCRL-14795, Ju n e 1966.


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p e r ton.nuclear chimney retorting system is successful.recovered if l o w e r grades of oil shale are amenable to the sa m e t reatment (see Fig. 6 ) .

About half of this reserve, or 160 billion barrels, could be recovered i f theEven gre ater amount of oil might be

2. Proposed Bronco ExperimentA grou p of about 24 domestic oil companies ha s been organized by CER-Geonuclea

Corporation to cooperate with the AEC, USBM, and LRL, in sponsoring Projec t Bronco,a nuclear explosion experiment in oil shale.determine whether an underground nuclear explosion can be used to pr ep are oil shaledeposi ts for insi tu retort ing on a commercial scale.shale is produced by the explosion, reto rting techniques will be t e s t ed i n a second phaseof the experiment. Major aspects to be studied in the retoring phase would include theproportion of oil recoverab le and the costs of operation.

The first objective of Br onc o is t o

If a reto rtable volume of broken

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The P rojec t Bronco plan is to detonate a 50-kiloton nuclear explosive at a depthof about 3000 feet in oil shale, at a government-owned site in the Picea nce Basin.Pr es ho t and postshot investigations at the Bronco sit e will be re la ted main ly to f rac tu r-ing of the oil sha le and to public safety. A careful seismic damage study w i l l beconducted. A typical in situ retorting scheme for oil shale is shown in Fig. 5. .

N o t ime scale has been established for the Bronco experiment, but it could prob ablnot be prepa red fo r detonation before midyea r 1968.coop erate in conducting the experiment and would sh ar e costs.

Industry and government would

D. Mining1. General Summary

Economical means must be found for mining increasingly deeper and lower gradeo r e bodies if the United States is to remain self-sufficient i n copper production.Figure 7illustrates the present domestic copper situation. A promising technique thatha s been proposed f o r extracting the copper from such low-grade ore is to brea k up theo r e body with nuclear explosions and t o pass a leach solution through the broken o re toremove the copper (s ee Fig- 8 ) . The g re at economic advantage of th is in-place


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processing is that no effort is spent in tran spor ting the huge quantities of low grad eor e that m ust be t reated. Nuclear explosives a r e the key to the method.

2. Proposed Sloop ExperimentA proposa l ha s been submitted by Kennecott Copper Corp oration to conduct a

nuclear in situ leaching demonstration experiment in a copper deposit owned by thecompany n e a r Safford, Arizona, This experiment, Pro jec t Sloop, is tentativelydesigned a s a %-kiloton nuclear detonation at a depth of about 1200 fee t . P re l iminaryexperimental design is being ca rr ied out by technical personnel fro m Kennecott CopperCorporation and LRL.

Following th e detonation and form ation of a chimney, the rubble will be leache din place t o determing whether copper can be recovered by this method. A pilot scaleprecipitation plant will be constructed on the ground surfa ce to investigate techniquesof separating the copper fr om both the leach solution and the radioactive contaminantsthat may be ca rr ie d from the explosion environment during the leaching operation.

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Int ere st has been shown in this experim ent by a number of o ther mining companies,and alterna te experiment sit es a r e available should the propose'd site prove unsuitablefo r any reason.

The problem of radioac tive co ntamination of the o r e ha s bee n studied, with thegeneral conclusion that it is an ent irely manageable problem.of these studies ar e:

Some significant re su lts

1) Concentrations of radioactive isotop es in the leach liquor would below enough that no specia l shielding fro m radiation ex posu re wouldbe needed.

(2) The most troublesome radioactive isotopes would be those of metals,such a s si lv er -l lO m, zirconium -95, niobium-95, and ruthenium-101;.Fortunately, the rela tively nonvolatile radionuclides would b e lockedin the congealed insoluble "puddle glass" at the bottom of the cavity,and only a sm al l percentage would ente r the leach liquor.metallurgical processing, o r a newly developed solvent extraction process,remove s virtually a li radioactive contaminants f r om the finished copper.

Subsequent


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3 ) Harmful radioactive contamination of ground water can be avoidedby careful si te selection.

E. Re sea rch and Development1. Hydrocarbon Experiment

Experim ents have been conducted to investigate the production and distributionof volatile radioactivity that might r esu lt fr om detonating a nuclear explosive in ahydrocarbon-rich material , such as petroleum reservoir rock. In the experiments,the nuclear device was packed in a measured amount of asphalt as the hydrocarbon-rich material . Analysis is not complete, but the results of this experiment a r e expected

' to show whether it is bet ter , fr om the standpoint of volatile radio activ ities, such askrypton-85 and tritium, to detonate the nuclear explosive for ga s stimulation applicationsin the petroleum reser voir m aterial o r close below in the m ate ria l containing less

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hydrocarbons.

2. Hardhat Perm eabili ty StudiesPerm eab ility of the rock outside the chimney crea ted by the Hardha t underground

nuclear experiment (5.4 kilotons at a depth of 939 feet in granite) has been determinedby drilling long holes and pressur'izing them with ai r. Results (given in Fig. 9) showthat permeability has increased 100-fold or more as fa r out as 215 feet fro m the shotpoint or 165 feet fro m the verti cal axis of the chimney. This repr es en ts a volume ofsome 30 million cubic feet in which the perm eability ha s been in crea sed 100-fold o rmore.extended because a collapsed dr if t prevented further measurements.

It could not be dete rmin ed how much far th er out the zone of high perm eab ility

3. Handcar Chimney StudiesA vertical exploratory hole was d rilled into the top of the chimney crea ted by the

Hatidcar underground nuclear experiment ( 1 2 kilotons at a depth of 1320 feet in dolomite).The top of th e chimn ey was found to be 223 fee t above the shot point, about 23% lessheight than had been expected on the bas is of e xperience fro m the Hardh at and Shoalshots in granite. The center of the void space at the top of the chimney, instead of


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being d ire ctly above the shot point, is displaced about 20 feet in the direction towardwhich the dolomite beds dip. Th is sugg ests a chimney that is somewhat t i lted r ath erthan vertical (see Fig. 10 . The rubble and void at the top of the chimney is shown inFig. 11.

Pressurizat ion te st s indicate a total void volume in the chimney, including theempty spa ce s between the rubble particles, of 1, 315,000 cubic feet (* 15 ).corresponds to a radius of 68 f 3 feet fo r the initial cavity produced by the shot. Anoptical surv ey and stereophotograp hs show that the void s pac e at the top of the chimneyabove the rub ble is mo re than half the volume of the orig inal cavity, indicating that lessbulking o ccu rre d than was expected.compared t o tha t of Har dha t which was 28 in hard rock.the rubble a r e relat ively small, 8 2 by volume being le ss than 1.5 feet in diameter.

This

Bulk porosity of the rubble is only about 1470, sThe part icles at the top of

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4. Cavity Collapse and Chimney DevelopmentMost proposed underground na tural res our ce development applications depend on

the form ation of rubble-f illed &iimney and on the physical characteris t ics of thatrubble and the wall roc k surr oun ding the chimney. Studies of the physics and inter-action of the explosion phenomena with variou s roc k m ate ria ls and geologic setting sa r e needed to understand the controlling facto rs in producing chimneys with favorablecharacteris t ics ; i. e. , high poro sity and permeability and well-fragmented rubble. Afirst experim ent ha s been performed to determ ine how chimneys develop above thecavity produced by a nuclear detonation in alluvium.needed for other ma teria ls that a re likely to be encountered in proposed underground

Chimney development studies a r e

applications.Information was obtained on the collap se of th e alluvium overlying a nuclear

explosion at a depth of 1125 feet. Collapse data were obtained for points on the surfa ceand beneath the surface down to a depth of 750 feet. As with most underground shotsin alluvium, the collap se of the mat er ia l overlying th e cavity extended all the way tothe surface arid produced a "subsidence crater. I f Surface collapse was monitored byphotographing a s e r i e s of tar ge ts resting on the surf ace above the shot; underground&ol lapse , b y special detectors called "slifer" cables . Pa rti cl e velocity and accelerationmeasure ments ivere also made


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Figure 12shows how collapse progre sses. A s expected from earl ier s tudies ,the collapse was mas sive and rapid once it began; the propagation rate of the collapsefront w a s 100 to 150 feet pe r second. A t a given depth the collapse was found to startabout 3 seconds e ar li e r in the ce nter of the chimney than at the edges. This lagcontinues as collapse prog res ses upward fr om the cavity to.the surfa ce.5. Effect of Wate r on Cavity Size

A study conducted at LRL ha s shown that t he w ater content of a medium affectsthe s ize of cavities produced by nuclear explosions. An equation was derived thataccu ratel y de scr ibe s the cavity dimension when the medium density, water content,depth of burst, and explosive energy ar e known.of 40 detonations intuff, alluvium, salt, and gran ite were calculated within the ac cu ra cythat cavity radius and othe r variables can be m easu red in the field.indicated that medium strength properties do not appear to influence the s iz e of thecavity.

6. Emplacement Hole Re-entry

Using this equation, the cav ity ra di i1

This study also

A technique ha s been developed for re- enter ing the cavity or chimney producedby a nucl ear detonation through the orig inal device emplacement hcle.prom ises t o be extrem ely useful f r om both technical and cost considerations in containedapplications.Salmon cavity.sep ara te hole of the s am e size and depth is realized.

This capability

A R P A sponsored the first field te st of this technique in re-enter ing theResults indicate that a savings of about 50% in the cost of dr i l l i nga

With the em placeme nt hole andhard war e designed specifically for re-e ntry purposes, an equivalent or greater savingwould accrue to future Plowshare programs in which a relat ively large diameter holeis useful f o r commercial downhole processing. An emplacement hole re -e nt ry sy ste m

4 is cur ren tly being designed for use in Gasbuggy,

7. Seismic Damage StudiesPrediction of architectural clamage f r o m seismic motion is beaornirg impor tant

An investigation of representative buildingso the feasibility of Plowshare projects.


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in Merc ury, Nevada, close to many nucle ar detonations within the Nevada Test Sitewas made to determine:

(1) The validity of peak particle velocity a s a damage criterion.(2 ) The peak particle velocity that causes m inor arc hitectural

damage to selected masonry s t ructures .3) The validity of the Hattiesburg, Mississippi, experienc e (Salmon

event).(4) The natural cracking rate for sim ila r struc tures in Nevada.Selected masonry s t ruc ture s in Mercury were inspected for cracking before and

after nuclear detonations and during periods of no nuclear test activity. Nuclea r te stdetonations gave peak particle velocities c lose to those experienced during the Salmon

;event.p e r second caused mo re cracking than normal (4 to 35 cracks in the 43 buildings);however, cracks at these low levels of motion a re not more sev ere than those occurring

Findings in du de evidence that peak partic le velocities of 0.17 t o 0.32 centimeters

naturally. During periods of no nuclear tes t activity a total of 2 1/2 c racks a dayoccurred natural ly in the 4 3 buildings under surveillance , indicating that the nuc learevents produced a number of c ra ck s equivalent to 2 to 14 days of norm al cracking.However, th er e a r e indications that for some period of time following a nuclear tes t ther a t e of natural ly occurring crack s is reduced.cra cks in a building a t some l at er time may be independent of the acc elera tion of crack-ing cau sed by th e low velocities cited.

This implies that the total number of

8. Code CalculationsComputer code development in support of the underground applica tions has

continued from Y 1965, o r was initiated during the yea r a s follows:( I ) Studies of the mathematical simulation of in situ retorting of oil shale.2 ) Development and testing of 2 -dimensional mathematical model of

fluid f low in porous and fractured media.3 ) Effects of heat transfer on fluid flow in a porous medium.

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m. EXCAVATIONA , General

Past re po rts have described experiments nece ssary to advance nuclear excavationtechnology to the stage where it can be used in la rg e construction projects.program has been designed to answ er the following ma jor tec hnical questions:

This

3)

How does cr a te r si ze depend on geologic pr oper ties ?Can cr at er s ize, sei smi c effects , air blast, and radioactivitydistribution of low yield experiments be extended to yields in themegaton range ?How do n4clear charges in a row nteract? Can projects for nuclearexcavation of channels through ter ra in varying in rock type andelevation be designed with confidence?

B. Field ExperimentsTo answer th ese questions, a number of experiments a r e required with excavation

explosives of increasingly higher yields. Two nuclear craterin g experiments, Cabrioletand Flivver, were designed at LRL and fielded in 1966, but they were not executedbec ause of possible conflict with the limited tes t ban treaty.

1. CabrioletCabriolet is planned as a 2.5-kiloton event in a hard, dry rhyolite rock medium

n e a r the anticipated optimum depth of burst.ba sic information on cratering, including experimental data to test LRL abili ty to maketheoretical calculations of cr at er s in earth materia ls with which LRL has no pr ior

The objectives of Cabriolet ar e to obtain

experience, and to develop a more complete understanding of the venting process andthe distribution of radioactivity. Seismic wave propagation an? ai r blast will also bestudied.


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i2. F l i v v e r 1

Fliwer I is planned by L R L as the first in a series oI LDw-yield and rel ati vel yThe main purpose of the Fl iwer s e r i e snexpensive nuclear crate ring experiments.

is to test new concepts in nucl ear excavation techniques, which a r e imposs ible orundesirable t o perf orm with high explosives. The objective is to find methods f orreducing the maximum s alv o yield in channel excavation, examp les of which m ay be"nibbling" (singly detonated ra th er than simu ltaneously detonated row cha rge s) andwater vapor enhancement.

.

Specifically, 5'liwer I is to be detonated in the Buckboard M e s a basal t at a scaleddepth of bu rst about equal to that of Danny Boy (0.42 kiloton), which is the only nuclearcr at er produced to &ate n basalt. The following a r e the specific objectives of Flivver I:

(1) To determine the reproducibility and the degree of scat tering inbasa lt c rater ing data.

(2) To test the radioactivity relea se concepts derived from Danny Boyand Sulky.

3 ) To esta blish th e capability of existing computer c odes t o predictnuclear cratering phenomena in a well-characterized hard rock.

C. Research and Development1. Device Development

General safety considerations and, more crit ica l currently, l imitations imposedby the test ban treat y req uire that excavation experiments re lea se minim al amounts ofradioactivity into the atmosph ere. During 1966, effort was expended on the developmentof thermonuclear explosives with a minimum of fission and induced radioactivities.Several device tests related to this pvogram were conducted by L R L during 1966.Special emplacem ent techniques a r e als o being studied a s a means of reducin g theamount of radioactivity rele ased by nuclear c rat eri ng detonations, and extensivecoristruction and planning have occurred i n preparation for a n experiment planned for1967.

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f 2. Crate ring CalculationsLRL ha s developed a technique for c lculating t h mound nd cav ity growth duri

nuclear and high explosive cratering events.num eric al approach to high intensity stress- wav e propagation, coupled with a unique

The calculations feature a standard

model of ma te ria l behavior.geophysic al logging at the s i t e of the event and fro m laboratory tests of cor e samples .With th is information, the code calculates the boundary of ejected material , the c ra te rradius, and the mass deposition.Boy experime nt; agre eme nt with the calculated rad ius and ejec ta deposition is quitegood. A next s t ep in the calculation effort is to determine the bulk volume of materialthat falls back into the c ra te r to obtain c ra te r depth.w i l l also have to be considered.

The properties of the earth ma terials are determined from

Figure 13 depicts the calculations m ade f or the Danny

Stability of the cratered s lope

3. A ir Blast CalculationsA i r blast fro m nuclear cratering shots is being studied at LRL by calculating

both the close-in ?ir shock and the long-range signal refrac ted in a layer ed atmosphere.A code has been developed for the refra cted signal and verified against observed datafr om the Scooter and Sedan events.10 percent of the mea sure d values in the Scooter high-explosive cra ter ing shot. A two-dimension al hydrodynamic com puter code ha s also been used to study close-in a i r blast.

The calculated peak o ve rp re ssu re agreed within

4. Cloud Diffusion StudiesA computer code has been developed at LRL fo r predicting the long-ter m diffusion

over varying fe rr a in of clouds generated by a nuclear explosion.used to inv estigate the influence of weather conditions and geogra phy on the shape, a re a ,and con cen tratio n of radioactive m ate ria l within the cloud. The stud y indicated thatairc raf t sampling procedures will have to be changed to obtain the data necessary tocheck any particular diffusion theory when applied to clouds a s larg e as those generatedb y underground nuclear explosions, and fo r duration of about two days.

The code has also been


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IV SCIENTIFIC STUDIES

A. Heavy Element P rog ramPlow shar e experiments in the heavy element prog ram during the yea r w ere aimed

at lear ning mo re about the exact ca pture path for producing v er y heavy isotopes, theextent of fission lo ss es in heavier targe ts, and improvements in design to incre ase theneutron flux. It has been concluded that neutron capture in protactinium is the mostlikely so ur ce of v ery heavy isotopes when uranium-238 is the init ial target.

On experime nts in which plutonium-242 and americium-243 wer e used a s targetmaterials, excessive fission losse s in the neutron capture sequence prevented theformation of signifidant amoun ts of ve ry heavy nuclides. In the LASL Cyclamen event,attainable flux levels were inc reased by an improvement in device design.

There is now some evidence that increased flux levels may not produce the d esiredheavy nuclei as easily as expected, particularly in the A = 259 mass chain.exposure in the uranium-238 targe t fro m the Cyclamen event was sufficient to havemade detectable amounts of fermium -259 and /o r mendelivium-259. However, none weredetected within a wide range of half-life limits. Possible explanations a r e being studiedand new theo retic al investigations into the half-life problem a r e being start ed.design changes a r e contemplated that should markedly increase the neutron exposureand should extend the expected heavy element yield well past the A = 259 point.

Neutron

Device


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FIGURE CAPTIONS

Fig. 1.

Fig. 2.Fig. 3.

Fig. 4.

FA ..

Fig. 6.

Fig. 7 .

Natural Gas Reserv oir Stimulation by Nuclea r Explosion. Nuc lear explosionscan be used t o stimulate the production of natura l gas f rom reser voi r rock ofsuch low permeabili ty that the g as cannot be produced economically fr om anorm al well. Nuclea r explosions would be se t off in the re se rv oi r rock t ocrea te la rg e chimneys of broken and cra cked rock from which th e ga s wouldflow mo re freely.a closeup of a cr os s section of one of the chimneys.Estimated Natural G a g Reserves in U. S.Actual and, Proje cted G as Re serv oir Capacity and Demand for Gas S torage inU. S. from'1965 to 1975.Storage of Natural Gas in Chimney Created by Nuclear Explosion.established that nuclear explosives in an im permea ble medium can produceunderground chimneys ,useful fo r com mer cial stora ge of n atu ral gas.chimney shown has a la rg e volume for the purpose of storing natural gas underpressure.

Th ree such chimneys a r e showm on the left; on the right is

Recoverable by Nuc lear Stimulation.\

It has been

The

In situ Retorting of Oil Shale in Chimney Cre ated by N uclear Explosion.re tor tin g of broken oil sh al e in a chimney crea ted by a nuclear explosion isshown.manne r suggested in the upper left.operation is shown at the lower left.r e q u i r e d to re to rt completely the broken o il shale in the 100-kiloton nuclea rchimney shown.U. S. Oil Shale Res erv es Showing Res erve s Recoverable with Nuclear Explosivesin Pice anc e Basin, Colorado.E. S. Copper Supply and in s i t u Copper in Leachable Rese rves.

The

Oil would be recovered from the oil shale by retorting slowly in theThe surface-to-chimney-to-surfaceTwelve to eighteen months would be


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f

I

-17-FIGURE CAPTIONS (continued)

Fig. 8 In situ Leaching in Nuclea r Explosion Area. This is a proposed technique forextracting copper from low-grade or e by breaking up the o r e body with a

nuc lear explosion (in th i s case, 75 kilotons - as shown on the left) and pas singa leaching solution through the broken or e to remo ve the copper. With the o rereco very operations ca rr ie d out at the surfa ce (as shown on the right), noexpense is involved in trans port ing huge quantities of low-grade or e fo rtreatment.

Fig. 9. Hardhat Perm eabili ty Measurements.Fig. 10. Schematic Section t h r o x h Handcar Chimney One Year af te r Explosion.Fig. 11. Han dcar Apical Void and Top of Rubble Column.Fig. 12. Schem atic eection of Subsidence Cr at er Development.Fig. 13. Calculations fo r Danny Boy Experiment.

a r e a nece ssary input to the code.zones to the subsequent detonation is determined from the code.

1

The grid l ine s delineate zones thatThe time histo ry response of each of these

The 0.42kiloton explosive was placed at a dept of 33 me ter s. At top, left, the deviceha s been detonated and the surrounding medium vaporized to a radius of 1.3meters . The press ure in the cavity at t h i s t ime is 1.6 megabars.milli seco nds (top, right , the cavity has expanded t o about 11 meters , thecavity pres sur e has been reduced to 35 bar s, and the ground surface hasexperienced a compressional shock wave and is moving upward.seconds (bottom left), the ca vity has expanded to about 15 me ters above thezero point and t h e cavi ty pre ssure is about 15 bars . All the ma terial above thecavity at t h i s t ime is esse ntially in fr ee fall with an ave rage velocity of 40me te rs per second, and no additional momentum is real ized from the lowcavity pressures.throwout calculation on the Danny Boy gr id at 100 milliseconds.

At 45

At 100 milli-

Shown at bottom right is the result of performing a free-fallThose zones

which had sufficient velocity to r is e above the orig inal ground sur fac e wereremoved from the grid and stacked on the surface. The bal l is t ic t rajectory ofthe zone determined it s final position on the surface,of the Danny Boy crater is shown superimposed (bottom, right).

The actual cross section


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- 1 9 -


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i

-22-


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.. i_. ~- --.- ... . . .. .. . .- 2 3 -


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-24 -


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4


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I964 MEASUREMENTSA A VERT ICAL

H O R I Z O N T A LA V E R T I C A LHORIZONTAL

( HOLE NUMBERS

I1965 MEASUREMENTS

i

1I- iZ\- 1 P R E C O L L A P S EC A V I T Y B O U N D A R YII

t

IO+A V . R A D I A L D I S T A N C E F R O M S H O T P O I N T FT)

Fig. 9.


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N70E-

F R I A B L E DOLO

Fig. 10.


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.

- - -. .. . -29-

SubsidenceCmterGround surface

av i t y rodius

Fig. 12.

li


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-30-


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LRL Internal Distr ibu t ionMichael M. MayC . FrankhauserW. Cl em en tsR. Ba tz e lG. DoroughP. StevensonB. RubinJ. GofmanJ. C a r o t h e r sC. McDonaldR. HerbstG. WerthJ. AllenJ. KahnG. HigginsA. HolzerM. NordykeJ. TomanJ. KnoxH. Tewes .TID File

i

DISTRIBUTION


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DISTRIBUTION (continued)

Exte rndl DistributionW. SlazakNuclear Cr aterin g GroupLivermore, CaliforniaJohn KellyDivision of Peaceful Nuclear Explosives (DPNE)Washington, D. C.John PhillipSan Francisco Operations OfficeBerkeley, California

wf f eds

Annual Report to Congress 1966 Plowshare 453700

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Transcript of Annual Report to Congress 1966 Plowshare 453700