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Full text of "Radiological applications program annual report for ..."

.CALIFORNIA, DEPT. OF WATER RESOURCES. 

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ULLETIN No. 144-69 



PIOLOGICAL 
APPLICATIONS 
PROGRAW 

A 




Annual Report fbi? FY 1968-69 




NORMAN B. LIVERMORE, JR. 

Secrefary for Resources 
The Resources Agency 



RONALD REAGAN 

Governor 

State of California 




BSvrt. OF CALIFORNIA 

r 'DAVl^ 



MAR 18 1970 
LIBRARY 



WILLIAM R. GIANELLI 

D/recfor 
Deportment of Water Resources 




Measuring soil moisture depletion of plum trees with nuclear moisture gauge. 



STATE OF CALIFORNIA 
The Resources Agency 

Department of Wa ter Resources 
BULLETIN No. 144-69 



RADIOLOGICAL APPLICATIONS 

PROGRAM 

Annual Report for FY 1968-69 



CopiM of this bulUtin at $1.00 Midi may b* ord«r*cl from: 

OfRc* of Procuramont 

DOCUMENTS SECTION 

P.O. Box 30191 

Socramvnto, California 95820 
MaU chKk* poyabU to STATE OP CALIFORNIA. 
California rotldontt add 5 porcont (oIm lax. 



December 1969 



NORMAN B. LIVERMORE, JR. 

Secretary for Resources 
The Resources Agency 



RONALD REAGAN 

Governor 

State of Colifornio 



WILLIAM R. GIANELLI 

Director 
Department of Water Resources 



Foreword 



This second report in the Bulletin No. 144 series covers activities of the 
Department of Water Resources' radiological applications program during the 1968-69 
fiscal year. 

The term "radiological" pertains to the study and use of atomic energy 
in the form of radioactive isotopes and X-ray apparatus. The Nuclear Engineering program 
of the Department was initiated in 1958, pursuant to House Resolutions 88 and 234, 
1957 California legislative session. H.R. 234, among other provisions, directed appoint- 
ment of a Subcommittee to ascertain, study, and analyze all facts relating to "....develop- 
ment in the general field of peaceful use of atomic energy as these may relate to California 
water problems;..." 

Clearly, the Legislature intended that the Department assume an active 
role in studying and developing nuclear energy applications - primarily power for project 
use, but in a broader sense all applications that might benefit water resources develop- 

!^ ment. These include radiological applications. 
The term "program" as used herein differs from the conventional meaning 
of the word in Department usage. The radiological applications program in itself is not 
productive of a result such as a plan, a design, or a recommendation for development of 
a water resource. Rather, it applies to the application of nuclear phenomena as an aid 
i in measurement, identification, tracing, or detection, and is thus a tool to be used in 
I Department investigative programs or construction projects. Typical among such programs 
I or projects are vegetative water use, soil salinity investigations, and nondestructive 
inspection of construction materials. 

This report includes brief descriptions of studies, investigations, and 
* tasks related to water resources in which radiological applications have played a part and 
may continue to do so in the future. 

f This report series is intended to keep those concerned with planning and 

development of water resources and the operation of water projects currently informed 
on radiation-related activities. 



William R. Gianelli, Director 
Department of Water Resources 
The Resources Agency 
State of California 
November 26, 1969 



state of California 
The Resources Agency 
DEPARTMENT OF WATER RESOURCES 



RONALD REAGAN, Governor 
NORMAN B. LIVERMORE, Jr., Secretary for Resources 

WILLIAM R. GIANELLI, Director, Department of Water Resources 
ALFRED R. GOLZE , Deputy Director 
JOHN R. TEERINK, Deputy Director 



POWER OFFICE 
James K. Cummings , Chief 

This report was prepared under 
the direction of 

Maurice B. Andrew Chief, Nuclear Unit 

by 

Irving Goldberg Associate Soils Specialist (Radiologic) 

Radiological Operations Officer 



IV 



CONTENTS 

Foreword iii 

Organization iv 

Acknowledgments vi 

Conclusions vii 

Abstract viii 

Chapter I - Introduction 1 

Chapter II - Radiological Applications 3 

Soil Moisture and Density Gauges 3 

Description of the Nuclear Method 3 

Nuclear Gauge Applications 3 

Vegetative Water Use 3 

Soil Salinity Studies 6 

Compaction Control 8 

Radiotracer Applications 8 

Littoral Transport Studies 8 

Other Radioisotope Tracer Projects 9 

Snow Management Research 9 

Radioisotope Flow Measurements 12 

Underground Nuclear Explosives 13 

Chapter III - Radiation Protection Program 15 

Introduction 15 

Summary of Department Activities 15 

ILLUSTRATIONS 

Measuring soil moisture depletion of plum trees with nuclear Frontispiece 

moisture gauge 

1 Soil permeability Studies, U. S. Bureau of Reclamation, 

Fresno, California 5 

2 Delta Fish and Wildlife Protection Study 7 

3 RIST Field Operations at Surf, California, February 1969 10-11 

4 Radiographic Operations in Weld Inspection 16 



n 



Acknowledgments 



The assistance provided by public agencies in helping to further the 
Department of Water Resources' radiological applications program has been singularly 
valuable. It has aided the Department in pursuing a more extensive program of study 
and application than otherwise would have been possible. For the cooperation and counsel 
provided by the following agencies, the Department is particularly appreciative. 

California Department of Public Health 
Bureau of Radiological Health 

California Department of Industrial Relations 
Division of Industrial Safety 

California Division of Highways 
Materials and Research Department 

University of California at Davis 
Department of Water Science and Engineering 

U. S. Forest Service 

Pacific Southwest Forest and Range Experiment Station 

U. S. Department of Agriculture 
Agricultural Research Service 

U. S. Department of Interior 
Bureau of Reclamation 

U. S. Department of the Army 
Corps of Engineers 

U. S. Atomic Energy Commission 
E. 0. Lawrence Radiation Laboratory 

In addition, the Department appreciates the cooperation of the many in- 
dividuals and the private organizations who gave generously of their time for consultative 
services and from whose experience in this emerging science theDepartment has benefited 
greatly. 



Conclusions 



Water resources development is a field in which the unique properties 
of radioisotopes have found many applications. Such uses have resulted in improving 
conventional practices and in making possible new measurements unachievable by other 
means. Probably the application most beneficial to the Department is the use of radioiso- 
tope gauging devices for determining moisture content and density of granular materials, 
such as soils. These devices have contributed significantly to the improvement of 
accuracy and dependability of soil moisture and density measurements. The Department's 
investigations of vegetative water use and compaction control have been particularly 
aided by utilization of nuclear moisture-density gauges. 

Investigations in which radioisotopes are used as tracers have shown 
promise of revealing information which cannot be obtained by any other known techniques. 
An example is the knowledge of sediment drift gained by using radioisotopic tracers to 
follow the movement of offshore underwater sediments. Use of radioisotopes to measure 
fluid flow and to rate pumps and turbines has shown potential value as an alternative 
to the conventional methods used by the Department. These applications are worthy 
of continued evaluation. No immediate needs are foreseen for nuclear explosives, but 
this is a technique that may ultimately find some application in excavation or ground 
water resources development. 

The widespread application of sealed radioactive sources to inspect 
construction materials is an unquestionably valuable technique in the Department's 
construction program. 

Because the use of radioactive material is subject to regulatory and 
licensing control, a radiation protection program has been developed as an adjunct to 
the applications program. This auxiliary program has functioned so successfully that 
since it began about ten years ago thousands of man-hours have been spent in handling 
potentially hazardous radioactive material without a single reportable instance of 
personnel overexposure. 



1 



Abstract 

The atom has been put to work, and its manifold benefits demonstrated, 
in many of the widely divergent activities carried out by the Department of Water 
Resources. Described in this report are radiological techniques which have been applied 
to more than 10 investigative programs of the Department or of other agencies with which 
the Department has cooperated. These uses range from development of a device to 
measure soil compaction in earthwork construction to determination of the suitability 
of a wildlife habitat - from making in-place measurements of the physical properties of 
a snow bank on a mountain top to following the offshore movements of drifting sand 
at the bottom of the ocean. 

In addition to describing the beneficial uses to which radioisotopes have 
been put, the report discusses several possible future projects connected with depart- 
mental functions which might be benefited by radiological applications. Among these 
are large-scale excavation by means of nuclear explosives and utilization of radiotracers 
in rating high -head pumps and turbines. 

The final chapter in the report describes the present functions of the 
Department's radiological protection program. 



viu 



Chapter I - INTRODUCTION 



Recognizing the useful role which can be played by the application of 
radioisotopes to engineering activities, the Department of Water Resources first made use 
of radioactive materials as long ago as 1957. At that time radiation applications were 
just emerging from their earlier status as laboratory curiosities. Demonstrably beneficial 
results of radioisotope uses had been obtained by the late 1950's, a decade after they 
were introduced. 

Bulletin No. 144-68* described about twenty-five of the Department's 
water resources-related activities in which radioisotopes have played a part. The 
significant benefits of radioisotopes already being achieved are generally recognized 
as indicative of the ultimate value of nuclear methods yet to be applied to the Depart- 
ment's water resources development program. 

This report describes current progress in radiation-related activities. 
Radiological applications in which the Department has participated during the past 
year may be conveniently divided into three categories: 

Soil moisture-density gauges 
Isotopes as tracers 
Nondestructive testing 

The report's final chapter discusses the Department's radiation protection 
program. This function is required under the provisions of the Department's Radioactive 
Material License, which permits possession and use of radioactive material. 



• "Radiological Applications Program - Annual Report for FY 1967-68", DWR Bulletin 
No. 144-68, September, 1968. 



■1- 



Chapter II - RADIOLOGICAL APPLICATIONS 



SOIL MOISTURE AND DENSITY GAUGES 

Rapid, precise, portable, nondestructive — these are the characteristics of the radiation 
scattering technique for soil moisture and density determination that make it valuable 
for a number of water resources-related applications. The nuclear method is admirably 
suited to determining rate of water use by a crop or compaction in an earth fill. This 
is because it permits repeated accurate measurements of moisture content or density 
changes over a long period of time to virtually unlimited depths of soil. 

Description of the Nuclear Method 

A detailed description of the nuclear method for determining moisture and density, 
contained in Bulletin No. 144-68, may be briefly summarized as follows: 

Soil moisture and density gauges consist of four inter- 
connected components: 1) a sealed source of radiation, 
2) a radiation detector, 3) a device for converting the 
detectoi^s signals into recordable count rates, and 4) a 
power supply. The detector is designed to respond 
exclusively to radiation which has been affected by that 
characteristic of the medium which is to be measured. 
When the source and detector are placed at the point of 
measurement, and the counting device started, a reading 
can usually be obtained within one minute or less. By 
means of a suitable calibration table, the appropriate 
moisture or density value can then be recorded. The device 
is then repositioned and another reading obtained imme- 
diately. The portable device can easily be moved by one 
man to several measurement locations in the field. 

Nuclear Gouge Applications 

Vegetative Water Use 

Neutron soil moisture probes have been used principally in the San Joaquin District 
by the Land and Water Use laboratory in Bakersfield, which has continued to develop 



and accumulate information on vegetative water use. The laboratory also functions 
as the key station for testing potential improvements in techniques and instruments 
tiiat might eventually be used statewide. 

The principal radiological accomplishments of the Bakersfield laboratory during the 
past year have been: 

Soil moisture depletion measurements to determine evapo- 
transpiration rates of a plot of table grapes and a plot 
of mechanically harvested canning tomatoes. The grapes 
were measured twice a month and the tomatoes were mea- 
sured approximately once a week. Eight moisture profiles 
were obtained. 

Development of a technique to determine evapotranspiration 
rates for shallow-rooted crops by measuring applied irriga- 
tion water and increase of soil moisture in initially dry 
soil profiles. A memorandum report, "Consumptive Use of 
Water by Spring Potatoes", describing this work in more 
detail, was published in May 1969. 

During the year, a new model of portable scaler, a component of the nuclear moisture 
gauge, was delivered to the Bakersfield laboratory. This instrument weighs less 
than the earlier scaler and is easier to maintain. However, the new scaler's greater 
ability to resolve pulses aniving at a rapid rate proved to be somewhat of an in- 
convenience. Its higher rate of resolution results in a higher apparent count rate 
for high moisture content soils than was obtained when the previous system was 
originally calibrated. Extremely careful field measurements of soils in this high 
moisture range were necessary to revise the existing calibration curves. At year's 
end, data which will become the input for the revised calibration were being pro- 
cessed for the computer. 

Joint investigations of vegetative water use utilizing neutron probes have been 
conducted with the University of California, Davis, and the U. S. Bureau of 
Reclamation, Fresno Field Division. Photographs of one of the Bureau of Reclama- 
tion's installations are shown in Illustration 1. 

The Department also contributes to the support of investigations by the Soil and 
Water Conservation Division, Agricultural Research Service, Southwest Branch, at 
Lompoc, California, which used neutron moisture meters in two investigations 
during the year. 

One of these investigations employed neutron moisture meters to measure deep 
penetration of rain water at naturally vegetated and artificially denuded sites. These 
data permit estimation of the amount of water penetrating beyond the root zone. 
From this information, methods are being developed to predict natural groundwater 
recharge by means of vegetative, soil, and climatic parameters in a computer model. 
Results obtained last year with the neutron moisture meter gave clear indications 
of the passage of soil moisture waves downward through the profiles. The data 



Illustration 1 SOIL PERMEABILITY STUDIES, U. S. BUREAU OF RECLAMATION, 

FRESNO, CALIFORNIA 




View of permeability test pit sheltered from precipitation by plastic cover. 




View into permeability test pit. 



View across permeameters in which barley crop is 
being grown. 



-5- 



also showed that in one 19-foot profile a depletion phase occurs at lower depths 
in the profile at the same time the accretion phase of a succeeding cycle is 
penetrating the upper part of the profile. In one instance, two annual accretion 
phases were measured simultaneously in one profile. 

Another investigation conducted last year by the Agricultural Research Service 
under sponsorship of the Department of Water Resources had as its objective the 
determination of relationships between evapotranspiration and various climatic, 
soil, and plant influences. To develop a greater understanding of the evapotrans- 
piration process, periodic neutron meter measurements are made of soil profile 
water contents in native vegetation. From these measurements the effects of 
changes in vegetation (burning off brush, mechanically clearing land) on soil 
moisture profile conditions may be determined. The amount and distribution of 
precipitation permit study of the source and movement of soil moisture. For example, 
in a year of lower than normal rainfall, it is possible to measure the quantity of 
moisture carried over from previous years which has been used in the evapotrans- 
piration process. 

Soil Salinity Studies 

Nuclear soil moisture gauges are also used in soil salinity studies. Such an 
application during the year occurred in the Suisun Marsh study, a joint undertaking 
by the Departments of Water Resources and Fish and Game as part of the Delta 
Fish and Wildlife Protective Study. The objective of the maish study is to deter- 
mine the effect of changes in channel salinity upon the soil salinity and hence 
upon the forage and migratory bird population. Changes in the salt load will affect 
forage production, which in turn affects the migratory bird population. 

Because the soils are highly organic, gravimetric determinations of soil water 
content are questionable when accomplished by the oven-drying procedures normally 
used for mineral soils. Although the quantitative soil moisture results obtained 
with the neutron probe in organic soils are not as reliable as those obtained from 
a probe in mineral soils, changes in soil moisture which may be determined by 
repetitive measurement of the soil moisture profile are reliably indicated. Soil 
moisture changes are required to determine the change in salinity from data obtained 
with electrical conductivity probes at the same time, date, and location. Additional 
data are also being obtained on the volume weights or densities of these soils 
through mathematical calculations based upon the soil moisture and electrical 
conductivity readings. Illustration 2 shows some of the field activity required for 
this study. 

Without doubt neutron soil moisture meters have been of great benefit in this 
measurement program. Data of comparable reliability could not have been obtained 
at a reasonable cost without these instruments. 

The past fiscal year has been one of concentration on the data collection program. 
Although a report on the Suisun Marsh investigation will be completed by December 
1969, the field measurements are expected to continue well into the 1969-70 fiscal 
year and the data obtained thereby included in a supplemental report. 



Illustration 2 DELTA FISH AND WILDLIFE PROTECTION STUDY 




Overall view of instrumented study 
site at Joice Island (DWR Neg. 3722-1). 




Simultaneously measuring salt concen- 
tration with conductivity meter and 
soil moisture content with neutron 
meter (DWR Neg. 3722-28). 




Aluminum boat transports recording 
instrumentation. White polyethylene 
shield (right of center) provides addi- 
tional personnel protection. (DWR 
Neg. 3722-24). 



-7- 



Compaction Control 

Following completion of the Thermalito Forebay-Afterbay embankment in the fall 
of 1968, the Department's nuclear compaction control equipment was moved to the 
North San Joaquin construction project at Byron. These instruments were intended 
principally to assist in controlling density of the soil-cement to be placed on the 
Clifton Court Forebay embankment. 

Precise control of moisture and density is absolutely essential in soil-cement 
construction, because the surface application is used in place of riprap and is 
occasionally subjected to high wave forces. Supplemental moisture and density 
data provided by the nuclear devices should contribute to better control of the 
embankment. Unfortunately, last winter's high water delayed placement of soil- 
cement. The work had barely commenced by the end of the fiscal year. Therefore, 
very little use of the nuclear devices was possible. They will, however, be used 
as required from the present through the completion of the embankment. 

RADIOTRACER APPLICATIONS 



Because of their extreme sensitivity and specificity, isotopic tracers are particularly 
valuable tools for following the pathways taken by a material through its environment. 

Radioisotopic tracers are thus useful in water resources-related activities. Although no 
new tracer applications were initiated in Department activities during the year, progress 
in some of the continuing investigations was followed with interest. 

Littoral Transport Studies 

The Department of Water Resources has been directly involved in a continuing series 
of tests in which radioisotope-tagged sand is used to determine the mechanics of 
offshore movement of sediment, particularly around headlands. This study, called 
RIST (Radioisotopic Sand Tracer Study), is under the combined sponsorship of the 
U. S. Air Force, the U. S. Navy, the U. S. Army, and the Department of Water Resources. 

The basic objectives of the RIST study are to develop methods and equipment for 
measuring sand transport and to obtain data that can be used to solve engineering 
problems related to maintaining coasts and waterways. These data would result in 
more precise knowledge of the characteristics of littoral material transport around 
headlands or supposed natural barriers to littoral drift, particularly sediment movement 
in the nearshore and offshore zones. Information will also be obtained on seasonal 
changes in rate, direction, and distance of littoral transport; average velocity of 
transport along a straight beach and around a headland; and the fundamental mechanics 
of sediment transport. 

The procedure is to label ("tag") with a radiotracer about 100 pounds of sand removed 
from the t)each under study. The tagged sand is then deposited in the surf at high tide 
and its movement is followed by four scintillation detectors housed in a 300-pound 
cylindrical device that rolls along the bottom as it is towed behind an amphibious 



vehicle. The underwater mobile detector system and the ancillaiy computer and data 
treatment programs were developed by and are operated during field tests by Oak Ridge 
National Laboratory. 

In the past fiscal year, three offshore injections of tagged sand were made. The first 
series of tests was conducted at Surf, California, in September and October, 1968. 
These operations were based on a laboratory study made on a model beach in May, 

1968. This model study proved valuable because the field work turned out to be the 
most successful to that date. 

In the first field test, a line source was constructed to extend from the beach face 
parallel to and through the surf zone. This was done by placing discrete samples 
of sand labelled with radioactive xenon in water-soluble bags at about 15-foot 
intervals. In the first test with this line source, an injection of 40 liters of sand was 
made under relatively calm conditions. In four days of monitoring, little movement was 
observed except along the beach face. In a second test, the waves were higher and 
the 40 liters of sand was rapidly dispersed. Two subsequent tests in which radioactive 
gold was used to label the sand gave generally the same results. Patterns were re- 
corded for a distance of 2,500 feet, although actual surveys covered approximately 
2 percent of the total offshore area involved. 

In February, 1969, radioactive gold was used in a field test conducted near Point 
Conception, California, offshore from Vandenberg Air Force Base. The test was 
proceeding most satisfactorily when an unfortunate mechanical breakdown of the 
detector vehicle prevented most of the planned measurement program. Photographs 
taken at the time of this test are shown in Illustration 3. 

A third test also utilizing gold-tagged sand was conducted during the week of June 16, 

1969. This test appeared to proceed without difficulty, and at fiscal year's end the 
data obtained therefrom were being analyzed. 

The project is progressing in orderly steps. Althou^ as yet no quantitative measure- 
ments of gross littoral drift have been made, each experiment provides valuable 
information that improves the next measurement. As each phase begins, these improve- 
ments are evidenced by more sophisticated equipment, greater confidence of personnel 
in handling the equipment and the data, and generally much more reliable results. 

Other Radioisotope Tracer Projects 

Although the Department of Water Resources currently has no official direct involvement 
in them, a number of water resources-related activities wherein radioisotopes are 
utilized merit close attention. 

Snow Management Research 

For a number of years, the U. S. Forest Service, Pacific Southwest Forest and 
Range Experiment Station, has been conducting snow management research into 
methods for studying and solving such problems as delaying total water yield. 
The research has resulted in development of a remote-controlled in situ snow 



Illustrations RIST FIELD OPERATIONS 



(Right) Loading tamp being lowered on LARC XV am- ^ ^' 

phibious vehicle. These vehicles are capable of riding 
out a 10-foot surf. 








(Left) Mobile detector vehicle and instrument shelter on 
deck of LARC XV vehicle. 



(Right) Mobile detector vehicle containing scintilla- 
tion detectors and auxiliary circuitry. Rocks on sea 
bottom dented the surface reinforcement rods. 




-10- 



AT SURF, CALIFORNIA, FEBRUARY 1969 




(Left) Mounted on bow deck of LARC XV, shielded 
container holds water-soluble plastic containers of 
sand tagged with radio-gold. 



(Right) On-board instrumentation includes (from left) 400- 
channel pulse-height analyzer and radiation detection 
equipment, navigational equipment, and print-out devices. 





(Left) Dr. David B. Duane of U. S. Amy Engineers, 
RIST project director, tosses dye marker into surf to 
determine feasibility of dropping tracers. Photo taken 
approximately 20 feet above sea level. 



II 



-11- 



density gauge. Measurements obtained with the gauge are permitting development 
of predictive formulas for linking solar radiation with snow melt. The data have 
shown that snow melts at densities lower than those commonly believed necessary 
to produce melt. The system is being prepared for the computer to provide direct 
read-out of the numerical values of interest. 

Radiotracer experiments designed to measure movement of water downslope in 
snowpacks have shown that large quantities of water move through dense snow 
layers inside the pack. Heretofore, the water was thought to pond on such layers 
and run downslope on top of even denser layers. The position of the water and its 
speed affect the rapidity with which it reaches the streams. 

The Department is watching work now underway to develop a radioisotopic method 
to quantitatively evaluate water movement in trees. Radioactive phosphorus in 
water solution is introduced into mature pine trees through freshly cut root tips. 
The tracer moves up the trunk in a discrete narrow band, and its progress is followed 
quite easily by portable survey equipment. The position and extent of tracer 
movement is also occasionally checked by making auto radio graph pictures of the 
cross section of trunks of tracer-treated trees that have been cut down. Microscopic 
thin-section specimens are also obtained to show the extent of physiological 
structures that transport the tracer-treated water. According to Forest Service 
reports, these experiments produced estimates of water use by individual trees 
that are in marked agreement with values obtained from measurements of inflow 
and outflow for an entire watershed. 

From these preliminary results it is apparent that additional development of the 
radioisotopic water movement method would be desirable. With further study, this 
tree tracing technique might some day prove useful as one of the methods for the 
collection of data used in watershed management studies. 

Radioisotope Flow Measurements 

The U. S. Bureau of Reclamation is continuing to improve methods for measuring 
flow rate in high-head turbines and pumps. A series of measurements has been 
completed at Flatiron Powerplant, Colorado, on a 6-foot-diameter turbine penstock 
and an 8-foot-diameter pump-turbine pipeline. Radioactive bromine has been used 
to make several measurements of discharge values, with sufficient success to 
encourage further woric. 

The project will be continued by applying the equipment in a series of demonstra- 
tion measurements in a few selected power and pumping plants under the jurisdiction 
of the Bureau of Reclamation. Progress in these demonstration projects will be 
followed with interest by the Department of Water Resources. 

Neutron activation is a widely used and rapidly developing laboratory technique for 
elemental analysis, but field applications are as yet less common. Using neutrons 
to induce radioactivity into an otherwise stable material and tracing the movement 
of the material by detecting the gamma radiation it subsequently emits has certain 
marked advantages over conventional methods. The relatively high penetrating 
power of both the incident neutrons and the emitted gamma rays makes feasible 



-12- 



the tracing of fluids moving in a great variety of media and minimizes sampling 
errors or interference due to changes in chemical composition. Although only pre- 
liminary results have been reported so far, there is reason to believe that a 
practical system can be developed to apply the neutron activation technique to 
water flow measurement. 

One recent development which may go a long way toward making neutron activation 
feasible is the commercial production of califomium-252. This man-made radioiso- 
tope emits neutrons spontaneously and intensely. It can be used in remote environ- 
ments because it requires no maintenance, no elaborate control system, and no 
power supply. The AEC* indicates that "Although less than 50 milligrams of 
califomium-252 are now in existence, several grams will be produced in the early 
1970's and hundreds of grams could be made available by 1980. A few micrograms 
are sufficient for many applications." 

The neutron activation analysis technique, with special regard to developments in 
the use of califomium-252, will be carefully observed for its potential in water 
resources applications, particularly in water flow measurement. 

Underground Nuclear Explosives 

Use of nuclear explosives has been considered as an altemative to conventional 
engineering means in water resources development. However, many problems stand 
firmly in the way of its use for this purpose in the near future. In addition to somewhat 
limited information on certain technical aspects of the detonation, stringent environ- 
mental, economic, and legal limitations also exist. 

It has been suggested that nuclear explosives might be used in construction for 
intercepting the natural movement of water, for detaining water in storage, or for 
conveying water. Also, the principal effect of nuclear detonation most likely to be 
useful to conserve and store ground water would be the rabble-filled collapse chimney 
that ordinarily results from a fully contained underground detonation. The chimney 
might function in four principal ways: 1) In a zone where a confining bed constrains 
the water, it might provide a highly permeable conduit, thus enlarging or prolonging 
the water yield from the aquifer system; 2) It might act as a "big well" to present 
a very large infiltration surface to the aquifer, thus increasing recoverable yield, 
facilitating recharge, or allowing injection of fluid waste products at suitable depths 
below land surface; 3) If it creates a suitable subsidence crater at land surface and 
reaches down to a saturated zone, it might help store surface runoff and help accelerate 
recharge of the zone; and 4) In massive impervious rock, it might afford underground 
void space for storing usable water. This last would be practical only if not restricted 
by the cost per unit volume of space. 

Although the concept of creation of new underground voids capable of storing ground 
water appears extremely attractive, it must be remembered that to date a nuclear 



*<< 



"Califomium-252, Its Use and Market Potential". Brochure published by USAEC, 
Savannah River Operations Office, Aiken, South Carolina. May, 1969. 



-13- 



device has not been detonated with the specific objective of providing underground 
storage of water. No reliable data based on controlled testing exist that can be used 
to evaluate certain problems in California. For example, how effective would deep 
nuclear explosions be in the relatively shallow saturated ground water reservoirs in 
California? Will confining clay layers, severed or shattered by nuclear explosions, 
tend to stay apart or will they blend together with time and tend to seal deeper 
aquifers? What size cavities can be developed, and how many acre-feet of usable 
new underground storage capacity can be created? What are the total costs of storing 
water underground by use of nuclear devices, as compared to conventional artificial 
recharge projects? How does one evaluate the impact of detonating nuclear devices in 
populated areas? What systems must be established for payment of any damages to 
man-made structures which might result from shock waves generated by nuclear 
explosives? Will a nuclear device exploded near one of California's many active faults 
trigger an earthquake? 

Some consideration has been given to using underground nuclear detonations to drain 
excess water collected this year in Buena Vista and Tulare Lake basins in San 
Joaquin Valley. However, geological and hydrological conditions in the saturated 
sedimentary materials beneath the valley floor do not appear favorable for creation of 
large new underground storage spaces. 

The Aquarius study, which is an investigation of the feasibility of applying nuclear 
explosives to improve the ground water supply in Arizona, began during the past 
year. It is being conducted jointly by the Atomic Energy Commission and the Depart- 
ment of the Interior, in response to a request by the Governor of Arizona. Results of 
the study will be read with interest. 

More definitive information should result from test detonations that currently are 
pending in other resource fields, such as natural gas. Beyond that, progress toward 
general understanding and possible acceptance of nuclear detonation in the field of 
water seems to rest on an experimental detonation of some demonstrably simple modi- 
fication of a natural hydrologic feature. 



-14- 



Chapter III - RADIATION PROTECTION PROGRAM 



INTRODUCTION 

Use of radioactive material is limited by specific regulations set forth by the U. S. Atomic 
Energy Commission. The authority to regulate possession and utilization of radioactive 
material has been delegated by federal law to the governments of a number of states. In 
California, the regulatory agencies are the Department of Public Health and the Division 
of Industrial Safety. 

SUMMARY OF DEPARTMENT ACTIVITIES 



Authority for supervision of radioactive material in the Department of Water Resources is 
vested in a Radiological Operations Officer whose duties and responsibilities for the 
radiation protection program have been discussed in detail in Bulletin No. 144-68. 
The following activities were carried out under the jurisdiction of the Radiological 
Operations Officer during the past fiscal year: 

1. The Department of Water Resources' Radioactive 
Material license, bearing an expiration date of April 23, 
1969, was renewed on June 9, 1969. The new license, 
which expires April 23, 1974, includes six radioisotopes, 
a total of nearly 2,800 millicuries contained in 27 sealed 
sources. 

2. A number of amendments to the Department's Adminis- 
trative Manual's radiation safety section were submitted. 
These were approved and released by the Department's 
Management Analysis Office in October, 1968. In June, 
1969, an extensively revised version of this section was 
submitted through channels for approval. These revisions 
are intended not only to update the regulations but to put 
the section on specific radiological protection rules in a 
more convenient booklet form. 

3. In November, 1968, a 2-day training program qualified 
13 new Radiological Operators in accordance with provi- 
sions of the Department's Radioactive Material License. 
At the 1968-69 fiscal year's end, a total of 17 active 
Radiological Operators had been trained and were fully 

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lustration 4 RADIOGRAPHIC OPERATIONS IN WELD INSPECTION 




Radiography on Edmonston pumping plant discharge line 
showing remote control cable connected to a shield 
containing radioactive source (on wood crate). Radiation 
survey meter visible on platform next to crate. 



Operating remote control source positioning device, 
Wind Gap Pumping Plant discharge line. Cables pass 
through inspection port at right. 





Operating remote control source positioning 
device, Angeles Tunnel surge chamber. This 
device is connected to shield in background, 
photo to right. 



Arrow 1 shows position to be occupied by radioactive source 
when run out on cable from shield in background; arrow 2 
shows reinforcing steel weld wrapped with a film packet. 



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I 



qualified to work with radioactive materials in specific 
Department programs. 

4. The number of individuals subject to film badge 
monitoring requirements grew during the year from 40 to 
nearly 70. This increase stemmed primarily from an inter- 
pretation of the State radiation protection regulations made 
by the Division of Industrial Safety in April, 1969. The 
DIS interprets the language of the personnel monitoring 
regulation to include in the film badge monitoring program 
Department inspectors who might inadvertently be exposed 
to radiation. Photographs of some of the operations required 
in radiographic weld inspections are shown in Illustra- 
tion 4. As an additional safeguard for our personnel, five 
kits containing portable survey meters and pen-type self- 
reading pocket dosimeters were distributed to the following 
divisions of the Department: 

South San Joaquin Division 

Wind Gap Pumping Plant 

A. D. Edmonston Pumping Plant 

Tehachapi-West Branch Division 
Angeles Tunnel 

Angeles Tunnel Surge Chamber 
Castaic Dam 

Provision has been made for supplying welding inspectors 
in the Mojave-Santa Ana Division with similar kits during 
the next fiscal year, when radiography of welds begins. 
These survey instruments are in addition to those with 
which gauging operations are conducted by Radiological 
Operators in the Northern District, Red Bluff; in the 
San Joaquin District, Fresno and Bakersfield; in the 
Central District, Sacramento; at the Technical Services 
Office, Bryte; and in the North San Joaquin Division, 
Clifton Court Forebay. 

5. The Department entered the 10th year in which its 
personnel and contractors incurred neither reportable 
injury nor overexposure to radioactive material. The film 
badge records did indicate four instances of small but 
significant exposures received by individuals being 
monitored. Although the amounts of radiation recorded 
did not exceed the statutory limit, or even the administra- 
tive guidelines set forth in the Department's Administrative 
Manual, informal investigations were nonetheless conducted 
by the Radiological Operations Officer, and steps initiated 
to lower the average exposure of these individuals. 



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