SWRHL-44r
PUBLIC HEALTH ASPECTS OF THE CIVILIAN
APPLICATIONS OF NUCLEAR EXPLOSIVES (PLOWSHARE)
PROGRAM
by
Delbert S. Barth
Bioenvironmental Research Program
Southwestern Radiological Health Laboratory
U. S. Public Health Service
Department of Health, Education, and Welfare
Las Vegas, Nevada
December 11, 1967
This study performed under a Memorandum of
Understanding (No. SF 54 373)
for the
U. S. ATOMIC ENERGY COMMISSION
-------
LEGAL NOTICE
This report was prepared as an account of Government sponsored
work. Neither the United States, nor the Atomic Energy Commission,
nor any person acting on behalf of the Commission:
A. Makes any warranty or representation, expressed or implied,
with respect to the accuracy, completeness, or usefulness of the in-
formation contained in this report, or that the use of any information,
apparatus, method, or process disclosed in this report may not in-
fringe privately owned rights; or
B. Assumes any liabilities with respect to the use of, or for damages
resulting from the use of any information, apparatus, method, or pro-
cess disclosed in this report.
As used in the above, "person acting on behalf of the Commission" in-
cludes any employee or contractor of the Commission, or employee
of such contractor, to the extent that such employee or contractor of
the Commission, or employee of such contractpr prepares, dissemin-
ates, or provides access to, any information pursuant to his employ-
ment or contract with the Commission, or his employment with such
contractor.
0039
-------
SWRHL-44r
PUBLIC HEALTH ASPECTS OF THE CIVILIAN
APPLICATIONS OF NUCLEAR EXPLOSIVES (PLOWSHARE)
PROGRAM
by
D. S. Earth
Bioenvironmental Research
Southwestern Radiological Health Laboratory
National Center for Radiological Health
U. S. Public Health Service
Department of Health, Education, and Welfare
Las Vegas, Nevada
Copy No. 39
Margaret M. Snow, EIR
SWRHL,, Las Vegas, Nevada
Presented at the International Health Symposium held
in Miami Beach, Florida
October 26, 1967
Under contract number SF 54 373 for the U. S. Atomic Energy
Commission
-------
ABSTRACT
A brief discussion of the work being carried on within the PLOWSHARE
Program is presented. This includes an introduction to studies in
the categories of research and development, excavation experiments,
scientific research experiments and underground engineering experiments.
Particular attention is devoted to public health aspects of the
excavation and the underground engineering applications. Potential hazards
which may be associated with ground shock as well as those related to
nuclear radiation are discussed in general terms. An inventory of
some radionuclide activities expected to be released from nuclear
cratering events of useful magnitude is presented.
-------
PUBLIC HEALTH ASPECTS OF THE CIVILIAN
APPLICATIONS OF NUCLEAR EXPLOSIVES (PLOWSHARE)
PROGRAM
by
D. S. Earth
Before discussing public health aspects of the PLOWSHARE Program
I believe it appropriate to spend some time discussing the PLOWSHARE
Program itself. The work being carried on under this program may be
divided into four categories ' ' research and development, excavation
experiments, scientific research experiments and underground engineer-
ing experiments.
The principal effort in the research and development category is
directed toward "obtaining a fundamental understanding of nuclear
explosive design, explosion phenomenology and uses of nuclear explosions
for civil, industrial and scientific purposes." ' ' The E. 0. Lawrence
Radiation Laboratory (LRL) in Livermore, California, which is operated
for the U. S. Atomic Energy Commission by the University of California,
is the major location for this work. Investigations are proceeding in
four major areas: "(1) development of the theory of nuclear explosion
effects in a variety of underground environments; (2) development of a
predictive capability for ground motion, acoustic waves and radioactivity;
(3) measurement and evaluation of physical data to support the theoretical
studies; and (4) feasibility studies and cooperative work with other
groups on the use of nuclear explosives in potential applications." (*•)
The principal effort in the category of excavation experiments
has been directed toward providing adequate information to the Atlantic-
Pacific Interoceanic Canal Study Commission in order that, the feasibility
of nuclear excavation may be considered in its final report to the
President. In transmitting the Third Annual Report of the Study Com-
mission to Congress, President Johnson stated:
-------
"There is little doubt that the construction of a sea-level canal
is technically feasible. The major questions to be resolved are:
--when it will be needed,
--whether it would be financially feasible, and
(2)
--where and how it should be constructed."
Because of unavoidable delays in starting field work in Panama
and Columbia and because the PLOWSHARE nuclear cratering experiments
needed to determine the technical feasibility of nuclear excavation
have experienced temporary postponement, the Study Commission has requeste
that its final report due date be changed from June 30, 1968, to December
1, 1970. This request is now pending before the Congress.
The nuclear cratering experiments planned for the future include
Projects CABRIOLET, BUGGY I, BUGGY II, AND SCHOONER. CABRIOLET,
possibly to be conducted in FY 68, is planned to be a 2.5 kiloton
explosion at a depth of 170 feet in hard rock at the Nevada Test Site.
"The explosion is intended to produce a crater with an expected depth
in the range of from 115 to 145 feet, and a diameter of from 425 to
460 feet. The project will be an important step in providing essential
data on basic cratering effects from a nuclear explosion occurring at
the apparent optimum depth in hard, dry rock,,
BUGGY I, planned for FY 68, "involves the simultaneous underground
detonation of five low yield nuclear explosives in even terrain at the
Nevada Test Site and is designed to produce a smooth ditch-like crater.
After BUGGY I, a second nuclear row charge, BUGGY II, is planned. The
experiment is planned to be performed adjacent to the BUGGY I crater
and will be designed to produce a second ditch-like cratar which will
connect with the BUGGY I crater. This experiment is also very important
because the current concept of nuclear excavation of canals and mountain
passes calls for such inter-connecting of a series of nuclear row charge.
craters."(1)
-------
SCHOONER "which is presently conceived to be a 10's to 100 KT
nuclear point charge in hard rock, possibly in the Bruneau River area
of southwestern Idaho, would provide the basis on which to extrapolate
to the higher yields needed for practical large-scale, nuclear excava-
tion." (*) This experiment may be conducted in FY 69.
"The nuclear excavation experimental program in later years
depends on the results obtained from the experiments just described.
It is expected that at least one higher yield nuclear row charge in
varying terrain and a major experiment or demonstration project com-
bining several experimental objectives would be required for purposes
of the canal studies." W
"Reduction of the amount of radioactivity released from nuclear
cratering explosions has always been recognized as crucial to the
ultimate success of the nuclear excavation program." *• '
Low-fission explosives, improved emplacement techniques and
decreases in radioactivity by shielding the nuclear explosive with
neutron-absorbing material have all been achieved. All of the above
add to the natural scavenging process which occurs during nuclear
cratering. "The combination of all these factors now allows the
prediction that, in cratering explosions of useful yields, the sum
of fission products airborne in the radioactive cloud and in the close-in
fallout should be about 100-150 times less than the amount estimated to
have been released from the 1962 SEDAN cratering experiment." ^ '
In the category of scientific research applications, attention
to date has been in two areas: heavy element experiments and neutron
physics experiments. Data collected to date indicate that "increased
neutron flux levels do not produce increasingly heavy nuclei as easily
as was originally believed." ^' Theoretical and experimental work in
this area is continuing. In the neutron physics experiments work is
continuing to develop the "techniques and equipment necessary to conduct
-------
particularly neutron fission and capture cross-section experiments,
using a nuclear explosion as a source of neutrons." ' ' All experiments
in the above two areas are conducted with completely contained under-
ground nuclear explosions.
In the category of underground engineering experiments, several
interesting projects are under study. All of these involve the use of
completely contained deep underground nuclear explosions to develop
and manage natural resources. "For example, a nuclear chimney and
related fracture zone located underground in natural gas bearing rock
formations of low permeability could act as a highly effective well
bore which may make it possible to recover natural gas which is now
economically unproducible. Located in oil shale or a low-grade copper
ore body, a nuclear chimney might also be used as an underground area
from which the oil, or copper, could be extracted. Situated in an area
regionally near, but locally remote from major population centers, such
a chimney could be used to store natural gas near the consumer-end of
gas transmission lines."
"The U. S. Bureau of Mines estimates that if nuclear gas stimulation
is successful, U. S. recoverable gas reserves would more than double
from under 300 trillion cubic feet to about 600 trillion cubic feet.
The USBM also estimates that if in-place retorting of domestic oil shale
in nuclear chimneys proves feasible, 160 billion barrels of oil might
be recovered. Similarly, nuclear chimneys might lead to the recovery
of millions of tons of copper which are not presently economically
recoverable and could provide needed storage for billions of cubic feet
of natural gas." ^ '
Project GASBUGGY, a joint AEC-U. S. Bureau of Mines - El Paso
Natural Gas Company project in Rio Arriba County, New Mexico, which
will be the first in a proposed series of natural gas stimulation
experiments, is currently scheduled for November 14, 1967.
-------
The Continental Oil Company in conjunction with CER Geonuclear;
Inc., Las Vegas, Nevada, has proposed Project DRAGON TRAIL which
recommends using a 40 KT nuclear explosive at a depth of 2,700 feet
in the Mancos B Formation in Rio Blanco County, Colorado. This
project would seek data similar to that which will be gathered in
GASBUGGY, but in a gas-bearing formation with different geological
characteristics.
The Austral Oil Company in conjunction with CER Geonuclear, Inc.,
Las Vegas, Nevada, has proposed Project RULISON which would involve the
use of two simultaneous nuclear explosions, at depths of 7,500 and
8,500 feet, to create a nuclear chimney extending vertically almost
the entire height of the gas-bearing strata of the Mesa Verde formation
at the proposed site near Rifle, Colorado.
"The Columbia Gas System Service Corporation, Columbus, Ohio,
the U. S. Bureau of Mines, AEG and LRL, Livcrmore, are now completing
a feasibility study of the use of nuclear explosions to create under-
ground storage area for natural gas. For the purpose of studying an
actual location, a site in central Pennsylvania is being used in the
feasibility study." This study has been given the name Project
KETCH.
The Kennecott Copper Corporation, Salt Lake City, Utah, AEC
and LRL, Livermore, have completed a joint feasibility study,
Project SLOOP, to evaluate the use of nuclear explosions for breaking
copper ore bodies to prepare them for in-situ leaching. A site in
Kennecott's Safford, Arizona, ore body has been considered in the
study and would probably be used as the location for any experiment.
The quality of the ore there is such that it cannot be economically
•
mined and treated by presently known and proved methods.
Project BRONCO is the name given to a joint AEC, CER Geonuclear,
U. S. Bureau of Mines, and LRL, Livermore, feasibility study of the
use of nuclear explosions to break up oil shale deposits for subsequent
in-situ retorting. This study was begun in February, 1967.
-------
In summary, all peaceful applications of nuclear explosives can
be broken down into two types—those in which the effects and products
of the explosion are fully contained underground, and those in which
the effects, and therefore to a limited degree some of the products
of an underground nuclear explosion, are apparent on the surface.
This latter type constitutes the field of nuclear excavation.
After that rather lengthy introduction we now arrive at the
major topic to be considered in this presentation--public health aspects.
Potential public health problems associated with the PLOWSHARE Program
are concerned with releases of radioactivity to man's environment and
with ground motion or ground shock. Since the latter is much easier to
evaluate it will be taken up first.
Abundant data have accumulated from the underground testing program
to date to allow reasonably accurate prediction of ground motion to
be expected as a function of distance from a given yield nuclear explo-
sion in a given medium. The prediction capability in this field is
adequate to determine how far out it will be necessary to evacuate people
to assure no health hazards will result. The prediction capability,
however; is not good enough yet to predict with confidence the distances
to which minor damage to structures may result.
A question which is invariably asked in this regard is whether
or not an underground nuclear explosion could trigger a major earth-
quake. The Nevada Operations Office of the AEG has a group of engineering
and scientific authorities, which form a subcommittee of their Panel of
Consultants, who have considered this question in some detail. '
It is their unanimous opinion that an underground nuclear explosion
would not start an earthquake. "The authorities point out that
an earthquake results when tens of years of accumulated strain is
suddenly released. Since it is impossible to have a natural earthquake
without having prior storage of energy--something that occurs over a
period of years--a man-made explosion could not "cause" a natural
earthquake. Theoretically, if a nuclear explosion were large enough
-------
if the immediate area were seismically active, and if the strain had
built up to a great enough degree in the near vicinity, there is a
remote possibility that the detonation might be followed immediately
by an earthquake which was on the verge of occurring anyway. However,
there is no known instance of a natural earthquake being triggered by
a man-made explosion. It would be necessary to conduct the explosion
miles deep and in an earthquake-susceptible area to get near a zone
where the stress was great enough for an incipient earthquake to be
(3)
triggered by the explosion."
The assessment of potential public health problems which may
result from releases of radioactivity to man's environment is a much
more difficult matter. A complete determination in this regard
requires, in the beginning, a precise description of the source term
(inventory of amounts of each radionuclide released to the environment).
Following that, knowledge of the initial deposition and interaction of
the radionuclides with terrestrial, aquatic and marine environments
is required and particularly knowledge of the interactions of the
radionuclides in the food web of man. In brief, one needs to know
the fate in the biosphere of each radioactive atom. Finally, knowledge
of the effects on man of low levels of radiation dose of different
types delivered over long periods of time is another area of uncertainty.
Obviously if one were to wait until all these answers were known
accurately, there would be no nuclear excavations performed in our
lifetimes and probably not in those of our immediate descendants. It
should be pointed out, however, that had such rigid standards been
imposed in the past we would probably not now have such things as
electricity, automobiles, atomic energy, airplanes, TNT and a host
of other things.
Potential radiation hazards of nuclear excavations must be
realistically placed in perspective with other accepted human hazards.
-------
8
We must base our radiation safety decisions in this matter on a careful
and cautious evaluation of the best information available today, to-
gether with a balance of known benefit vs. probable risk as reflected
in accepted radiation protection standards. Is this not the same
safety dec is ion -making process followed in every other industry? Of
course, when new pertinent information comes to light, past safety
decisions must necessarily be re-evaluated in view of the new knowledge.
The remainder of this presentation will consider what is known
at this time concerning the total knowledge which is required. We
are not in as bad shape as some would have us believe.
A recent document from LRL has given a statement of con-
siderable interest concerning the source term.
"In order to plan for major excavation projects, the following
factors relative to release of radioactive debris should be taken
into account: The amount of radioactivity airborne in the cloud
and in the fallout is minimized by scavenging during the venting
process, by special emplacement techniques, by utilizing minimum
fission explosives, and by employing extensive neutron shielding.
Based on reasonable assumptions about these factors, the following
information can be used in planning for cratering events of useful
magnitude. For each individual nuclear explosive detonated, the sum
of fission products airborne in the radioactive cloud and in the
fallout can be expected to be as low as the equivalent of 20 tons.
The tritium release may be less than 20 kilocuries per kiloton of
total yield. The sum of activation products airborne in the radio-
active cloud and in the fallout may be expected to be as low as
the amounts shown in the following table;
-------
Nuclide
24,
Na
32,
45
Ca
54,
Mn
56,
Mn
55
Fe
59
Fe
185,
W
187,
W
203Pb
Other
REPRESENTATIVE SET OF INDUCED RADIOACTIVITIES
AT DETONATION TIME
(Total in Cloud and Fallout)
Nuclide Production, Kilocurie for Yield of
100KT 1MT
200
0.1
0.01
0.1
600
0.04
0.04
6
300
1,000
15
800
0.4
0.03
0.3
2,000
0.15
0.15
10
500
7,000
20
10MT
2,000
0.8
0.06
0.7
5,000
0.3
0.3
14
700
20,000
40
,,(4)
A listing of fission products to be expected from 20 tons equivalent
of fission can be found in various references in the unclassified literature.
Reference 5 is one such reference.
With the source terms in view, the next step in determining potential
human hazards is to identify the critical radionuclides by comparing
predicted amounts to accepted radiation protection standards. Since
maximum permissible concentrations are based on air, water and sometimes
milk levels, it is first necessary to calculate probable distributions
of the radionuclides based on diffusion models and meterological
parameters. Various ecological concentration processes must also be taken
into consideration. A complete radiation safety analysis must consider
radiation dose to humans resulting from external gamma radiation together
-------
10
with dose from internal emitters, including both ingested and inhaled
radionuclides. The critical radionuclides may be different for each
type of human dose. To calculate dose from ingested radionuclides it
is essential to identify the critical material in the human food web.
Suffice it to say that considerable data have accumulated over
the years in the above areas. In addition, experiments are under way
to generate missing pieces of data. An extensive bioenvironmental
evaluation of the areas under consideration for a sea level canal is
currently under way by Battelle Memorial Institute, Columbus, Ohio,
under contract to the AEG. Results of this study will be available in
time for them to be evaluated by the Canal Study Commission prior to
the submission of their final report to the President. In particular
Battelle has studies under way in the following general research areas;
dose estimation, human ecology, agricultural ecology, terrestrial
ecology, hydrology and radionuclide distribution, freshwater ecology,
physicochemical oceanography and marine ecology and resources .
The problems are many and varied but they are not insurmountable
if we are willing to settle for somewhat less than the ideal which,
of course, would be complete knowledge of all the factors previously
mentioned.
The Battelle program will not shed any new light on potential
effects on humans of low levels of radiation delivered over a long
period of time. Under the linear concept of damage there is a small
but finite risk in this area which must be accepted if benefits are to
be derived. It should be pointed out that, at this time, it is just
as impossible to prove that there is any risk in this regard as it is
to prove that there is n£ risk.
Some comment should be made here concerning potential radiation
problems which may be associated even with completely contained under-
ground explosion applications such as the natural gas stimulation and
-------
11
the petroleum and copper recovery proposals. Natural gas, petroleum
and copper resulting from these experiments would be contaminated to
some extent with radioactive materials for some time. Determination
of the magnitude of the problems which this will pose to these appli-
cations must await successful experiments in each area. However, pro-
posals are already being made for methods to reduce the radioactive
contamination of natural gas, petroleum or copper which may result from
these applications.
This discussion has probably raised more questions in your mind
than it has provided answers. The day of applications of nuclear
explosives to peacetime problems is just beginning to dawn. No one
really knows what it holds in store for us. Without doubt, however,
success in presently planned experiments will inevitably lead state,
national and international health agencies into an entirely new era
of public health actions which, at this time, can only be partially
defined.
An International Symposium with the same subject as this paper
is currently being planned for fall, 1968, in Las Vegas, Nevada, under
the sponsorship of the U. S. Public Health Service. It is expected
that this Symposium will shed much more light on this subject area
than has been possible today.
In summary I would like to quote from a speech made by Dr. Glenn T.
Seaborg, Chairman, U. S. Atomic Energy Commission at Rio de Janeiro,
Brazil, on July 3, 1967. ' ' "... the United States has indicated
its readiness to enter into international arrangements to furnish
peaceful nuclear explosive services which can be safely undertaken,
whenever appropriate devices and technology are available. These
services would be supplied on a non-discriminatory basis, on attractive
terms identical for both United States and overseas customers. More-
over, when those devices and their applications become feasible, there
will be no scarcity of the necessary units and all proper uses can be
accommodated without delay."
-------
12
References
1. Statement on the Civilian Applications of Nuclear Explosives
(PLOWSHARE) Program, U. S. Atomic Energy Commission, F.Y. 1968
Authorization Hearings before the Joint Committee on Atomic
Energy.
2. Atlantic-Pacific Interoceanic Canal Study Commission -
The President's message to the Congress transmitting the
Commission's 3rd Annual Report, August 8, 1967.
3. News Release - Atomic Energy Commission Nevada Operations
Office, Las Vegas, Nevada NV-67-103, August 18, 1967.
4. Memorandum from Edward H. Fleming, Assistant Head, Chemistry
Department, May 11, 1967.
5. UCRL-50243 Fission Product Decay Chains, Volume II.
6. Bioenvironmental and Radiological-Safety Feasibility Studies,
Atlantic-Pacific Interoceanic Canal, January 13, 1967,
Battelle Memorial Institute, Columbus, Ohio.
7. Remarks by Dr. Glenn T. Seaborg, Chairman, U. S. Atomic Energy
Commission at Rio de Janeiro, Brazil, July 3, 1967.
-------
DISTRIBUTION
1 - 15 SWRHL, Las Vegas, Nevada
16 James E. Reeves, Manager, NVOO/AEC, Las Vegas, Nevada
17 Robert H. Thalgott, NVOO/AEC, Las Vegas, Nevada
18 Chief, NOB, DASA, NVOO/AEC, Las Vegas, Nevada
19 D. H. Edwards, Safety Evaluation Div. , NVOO/AEC, Las Vegas, Nev.
20 R. C. Emens, NTS Support Office, AEC, Mercury, Nevada
21 Martin B. Biles, DOS, USAEC, Washington, D. C.
22 JohnS. Kelly, DPNE, USAEC, Washington, D. C.
23 P. A. Allen, ARFRO, ESSA, NVOO/AEC, Las Vegas, Nevada
24 G. D. Ferber, ARL, ESSA, Washington, D. C.
25 - 29 Charles L. Weaver, NCRH, PHS, Rockville, Maryland
30 Northeastern Radiological Health Lab. , Winchester, Mass.
31 Southeastern Radiological Health Lab. , Montgomery, Alabama
32 D. W. Hendricks, Safety Evaluation Div. , NVOO/AEC, Las Vegas, Nev.
33 Mail & Records, NVOO/AEC, Las Vegas, Nevada
34 University of Nevada Library, Reno and Las Vegas, Nevada
35 - 36 USAEC Div. of Tech. Inf. Extension, Oak Ridge, Term.
------- |