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United States. Natlo/Requirements for an QC100 .U57 V603;1981 C.I NBS-PUB-R 1981 NBS SPECIAL PUBLICATION 603

U.S. DEPARTMENT OF COMMERCE/National Bureau of Standards

Requirements for an Effective

National Ionizing Radiation

Measurements Program

-QC

100

.U57

NO. 603

1981
NATIONAL BUREAU OF STANDARDS

The National Bureau of Standards' was established by an act ot Congress on March 3, 1901. The Bureau's overall goal is to strengthen and advance the Nation's science and technology

and facihtate their effective application for public benefit. To this end, the Bureau conducts

research and provides: (1) a basis for the Nation's physical measurement system, (2) scientific and technological services for industry and government, (3) a technical basis for equity in trade, and (4) technical services to promote public safety. The Bureau's technical work is per- formed by the National Measurement Laboratory, the National Engineering Laboratory, and

the Institute for Computer Sciences and Technology.

THE NATIONAL MEASUREMENT LABORATORY provides the national system of

physical and chemical and materials measurement; coordinates the system with measurement

systems of other nations and furnishes essential services leading to accurate and uniform

physical and chemical measurement throughout the Nation's scientific community, industry,

and commerce; conducts materials research leading to improved methods of measurement,

standards, and data on the properties of materials needed by industry, commerce, educational

institutions, and Government; provides advisory and research services to other Government

agencies; develops, produces, and distributes Standard Reference Materials; and provides

calibration services. The Laboratory consists of the following centers:

Absolute Physical Quantities^ — Radiation Research — Thermodynamics and

Molecular Science — Analytical Chemistry — Materials Science. THE NATIONAL ENGINEERING LABORATORY provides technology and technical ser- vices to the public and private sectors to address national needs and to solve national problems; conducts research in engineering and applied science in support of these efforts; builds and maintains competence in the necessary disciplines required to carry out this research and technical service; develops engineering data and measurement capabilities;

provides engineering measurement traceability services; develops test methods and proposes

engineering standards and code changes; develops and proposes new engineering practices;

and develops and improves mechanisms to transfer results of its research to the ultimate user. The Laboratory consists of the following centers:

Applied Mathematics — Electronics and Electrical Engineering^ — Mechanical

Engineering and Process Technology^ — Building Technology — Fire Research —

Consumer Product Technology — Field Methods.

THE INSTITUTE FOR COMPUTER SCIENCES AND TECHNOLOGY conducts

research and provides scientific and technical services to aid Federal agencies in the selection, acquisition, application, and use of computer technology to improve effectiveness and

economy in Government operations in accordance with Public Law 89-306 (40 U.S.C. 759), relevant Executive Orders, and other directives; carries out this mission by managing the Federal Information Processing Standards Program, developing Federal ADP standards

guidelines, and managing Federal participation in ADP voluntary standardization activities; provides scientific and technological advisory services and assistance to Federal agencies; and

provides the technical foundation for computer-related policies of the Federal Government.

The Institute consists of the following centers:

Programming Science and Technology — Computer Systems Engineering.

'Headquarters and Laboratories at Gaithersburg, MD, unless otherwise noted; mailing address Washington, DC 20234. ^Some divisions within the center are located at Boulder, CO 80303.
Requirements for an Effective

National Ionizing Radiation

Measurements Program

A Report to the Congress by the

National Bureau of Standards

Prepared in cooperation with

The Conference of Radiation Control Program Directors, Inc.

Center for Radiation Research

National Measurement Laboratory

National Bureau of Standards

Washington, DC 20234

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

,5 NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

issued March 1981

National Bureau of Standards

Library. E-Ol Adnu'n, Bidg.

MAR I 6 1981

not ctfc . ~Ke-(

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Library of Congress Catalog Card Number: 81-600005

National Bureau of Standards Special Publication 603

Nat. Bur. Stand. (U.S.), Spec. Publ. 603, 139 pages (Mar. 1981) CODEN: XNBSAV

For further information regarding this report please contact Elmer H. Eisenhower, Chief, Office of Radiation Measurements,

Center for Radiation Research, National Measurement Laboratory, National Bureau of Standards, Washington, DC 20234.

U.S. GOVERNMENT PRINTING OFFICE

WASHINGTON: 1981

For sale by the Superintendent of Documents, U.S. Governrnent Printing Office, Washington, D.C. 20402

Price $2.25 '-• (Add 25 percent for other thafi"U.S. mailing)
Abstract

This report was prepared for the Senate Committee on

Commerce, Science, and Transportation in response to its recommendation that the National Bureau of Standards review , in

cooperation with the Conference of Radiation Control Program

Directors, the need for intermediate calibration laboratories

for ionizing and nonionizing radiation. Conclusions relevant

to the measurement of nonionizing radiation are presented in

a separate report. This report is a description of the elements

of an effective support system for ionizing radiation measurements,

an evaluation of current needs in this area, a description of

necessary measurement accuracies for specific applications, and

a discussion of possible options to improve the support system.

The focus is on institutional and technical actions needed to

assure the accuracy of ionizing radiation measurements for the

protection of workers and the general public.

Key words: Beta rays; Federal and State laboratories; gamma

rays; instrument calibrations; intermediate calibration laboratories; ionizing radiation measurements; measurement accuracies;

neutrons; radiation dosimetry; radiation protection; radiation

standards; x rays.

Contents

Abstract iii

Executive Summary vii

Glossary xiii

Organizational Abbreviations xvi

1. Statement of the Problem 1

1.1 Pervasiveness of Ionizing Radiation 1

1.1.1 Naturally-Occurring Sources 1

1.1.2 Man-made Sources 1

1.2 National Concern with Radiation 3

1.2.1 Public Concerns with Risk 3

1.2.2 Benefits of Radiation 4

1.3 Regulation of Radiation 5

2. Measurement Needs vs. Present Capabilities 8

2.1 Needs for Accuracy in Radiation Measurements 8

2.1.1 Medical 8

2.1.2 Occupational 9

2.1.3 Environmental 9

2.2 Comparison of Needs with Capabilities 10

2.2.1 Medical Radiation 10

2.2.2 Occupational Radiation Protection 12

2.2.3 Environmental Radiation 14

3. Measurement Support System 16

3.1 Necessary Elements of a Radiation Measurement

Support System 15

3.1.1 Measurement Standards 16

3.1.2 Calibrations..... 16

3.1.3 Field Instruments 17

3.1.4 Data Analysis and Recording 17

3.1.5 Measurement Quality Assurance 18

3.1.6 Documented Procedures 18

3.1.7 Research and Development 18

3.1.8 Education and Training 19

3.2 Institutional Structures for Measurement Support 19

3.2.1 International Standards Laboratories 19

3.2.2 National Standards Laboratories 19

3.2.3 Intermediate-Level Laboratories 21

3.2.4 Field-Level Entities 21

3.2.5 Voluntary Standards Writing Organizations 22

3.2.6 Professional Societies 22

3.3 Status of Present Measurement Support System 23

3.3.1 Strong Points 23

3.3.2 Weak Points 25

3.4 Priorities for Improvement of Ionizing

Radiation Measurements 26

V
4. Possibilities for Improving Measurement

Traceability Through the Intermediate Level 28

4.1 Enlarge NBS In-House Calibration Services 28

4.2 Use Existing DOE and DOD Laboratories 29

4.3 Regulatory Agencies Provide Intermediate Level 30

4.4 Establish Federally-Supported Regional

Calibration Laboratories 31

4.5 Foster Private-Sector Intermediate

Calibration Laboratories... 32

4.6 Establish State-Run Regional Calibration

Laboratories 34

5 . Analysis 35

5.1 Needed Programmatic Actions 35

5.1.1 Personnel Monitoring 36

5.1.2 Occupational Radiation Survey 37

5.1.3 Radiation Therapy 37

5.1.4 Environmental Radioactivity 38

5.1.5 Ambient Radiation 38

5.1.6 Medical Diagnosis 38

5.2 Needed Institutional Structures and Functions 39

5.2.1 Current Situation 39

5.2.2 Recommendation: Strengthen IntermediateLevel Institutions 41

5.3 Proposed Plan for Implementation , 45

References 49

Appendix A. Final Report of Task Force on Radiation

Measurements, Conference of Radiation

Control Program Directors A-1

Appendix B. Report on Ionizing Radiation Measurement

Criteria for Regulatory Purposes, by

Conference of Radiation Control Program

Directors B-1

Appendix C. Growth and Economic Value of Applications

Involving the Use of Ionizing Radiations:

Five Examples ; C-1

Appendix D. Summary of Recent Estimates of Occupational

Exposure to Ionizing Radiation D-1

Appendix E. Summary of State and Local Radiological

Health Program Activities E-1

vi
Executive Summary

This report was prepared for the Senate Committee on

Commerce, Science, and Transportation in response to its

recommendation that the National Bureau of Standards review, in

cooperation with the Conference of Radiation Control Program

Directors, the need for intermediate calibration laboratories

for ionizing^ and nonionizing radiation. Conclusions relevant

to the measurement of nonionizing radiation are presented in a separate report.

Included in this report is a description of the elements

of an effective support system for ionizing radiation measurements, an evaluation of current needs in this area, a description of necessary measurement accuracies for specific

applications, and a discussion of possible options to improve

the support system. The focus is on institutional and

technical actions needed to assure the accuracy of ionizing

radiation measurements for the protection of workers and the

general public.

Problem

Reliable measurements have been demonstrated for only a fraction of the ever-increasing uses of ionizing radiation and

for human exposures to this radiation. The increase in applications of ionizing radiation has resulted in numerous regulations intended to protect the public from potential

radiation hazards. Compliance with these regulations is

generally determined by measurement of radiation levels resulting from a particular radiation source. Thus it is essential

that the measurements be adequate if compliance is to be

determined and public safety assured.

Currently, 19 Federal agencies have some radiation health

and safety authority, and over 100 enabling acts for radiation

protection regulations have been passed by the States. Effective, equitable enforcement of regulations requires measurements that are reliable, uniform, and sufficiently accurate.

Uniformity of measurement results is of primary importance for

conformity between the regulator and regulatee. Adequate

accuracy and uniformity can be achieved when measurements

are made in terms of the national physical measurement standards

maintained by NBS, and are therefore consistent with these

standards. To achieve the necessary degree of consistency,

actions and programs such as calibrations and measurement

quality assurance tests may be employed. These provide the

route by which field measurements can be traced to the

national standards

.

^Italicized words are defined in the glossary which follows.

VI i
Measurement Needs vs. Present Capabilities

The report summarizes the required accuracy and the

currently available accuracy for various types of radiation.

Accuracy requirements resulting from field measurements of

radiation vary with the type and intensity of the radiation.

In general, the greater the intensity the better the accuracy

needed:

"Radiation therapy, where large doses are required for

killing cancerous cells, requires a dose measurement

accuracy of about 3 percent. Diagnostic x rays, on the

other hand, require measurement accuracies of 10 percent

because the dose is smaller.

"Occupational safety measurements for ionizing radiations

frequently require accuracies of about 20 percent for

area surveys and about 30 percent for personnel dosimeters. ^ "Accuracy requirements for environmental field measurements are typically in the range of 10 to 20 percent,

relaxing to a factor-of-two for very low level measurements, such as normal background radioactivity in natural

materials

.

The report also identifies several areas where improvements in measurement capabilities are needed to meet the

requirements set forth by regulations or good practice.

Accuracy requirements become more rigorous as one moves

through the various levels of the measurement support si/stem,

starting with field measurements, then to the intermediate

level calibrations, and finally to the national standards

maintained by NBS . Adequate accuracy at the higher levels

is a prerequisite for satisfying accuracy needs at the lower

levels. In the medical applications three areas of need stand

out:

"The accuracy of cobalt-60 radiation therapy dosimetric is

in a nearly satisfactory state at all levels, but the

accuracy of radiation therapy dosimetry for high energy

X rays and electrons is not satisfactory either at NBS or

at intermediate level laboratories.

"The accuracy of neutron dosimetry, a new method for radiation therapy, is also unsatisfactory.

"Accuracy available at hospitals and clinics for medical

diagnostic x rays has not been documented, although

capabilities at the Federal-sector intermediate laboratory level and NBS levels are adequate.

In occupational radiation protection, there is no generally

available mechanism for demonstrating the accuracy of field

V 1 i i
measurements such as area survei/s . In personnel monitoring

,

required accuracies are not available at the field level, the

intermediate level, or in some cases at NBS.

Environmental radioactivity measurement accuracies achieved

vary widely. Intermediate level services, in the form of

radioactivity standards, are available from the EPA, but do

not provide complete coverage of the field. NBS standards and

calibration accuracies for environmental radioactivity appear

to be generally satisfactory, and standard reference materials

enable the users to calibrate their instruments or procedures in

terms of the national standards.

Measurement Support System

To ensure consistent and accurate measurements at the

user level, there are many necessary technical elements of the

measurement support system. These include measurement standards,

calibrations, field instrumentation, data analysis and recording,

measurement quality assurance (MQA), documented procedures,

research and development, and education and training. To

ensure that the system works properly, each element must

receive proper attention and must function adequately.

In addition to the technical elements, there are necessary

institutional elements of the measurement support system:

international standards laboratories, national standards

laboratories, intermediate level laboratories, field level

entities, voluntary standards organizations, and professional

societies. An effective system is dependent upon the achievement of adequate institutional arrangements in conjunction

with the necessary technical capabilities.

The current measurement support system has many strong

points. National measurement standards for many radiation

quantities exist. Calibrations are provided by NBS for many

instruments used by intermediate standards laboratories and

others. The framework is in place to support and to develop

voluntary standards needed for good measurement practice.

Several Federal regulatory agencies and professional societies

have established intermediate standards laboratories.

Nonetheless, a number of important deficiencies exist.

National standards need to be developed or improved in the

areas of (1) dosimetry for high-energy x rays and electrons,

and fast neutrons; (2) monitoring occupational exposure to

neutrons and beta rays; and (3) measurement of low-level radiation in the general environment. Instrument calibrations and

measurement quality assurance services are not available to all

who need them. Only a few measurement traceable intermediate

standards laboratories exist at this time. A pressing need is

seen for intermediate standards laboratories to provide services

ix
to state and local regulatory agencies. Instruments available

for use at the field level are sometimes inadequate, particularly for measurement of beta and neutron radiation. Other

deficiencies include the lack of adequate education and training and an obvious lack of coordination of measurement-related

efforts among the various Federal, state, and local regulatory

agencies

.

Options for Institutional Improvements ^ Several ways of restructuring institutional relationships

to improve measurement traceability can be considered. A

greatly expanded role for NBS in providing direct calibration i services to the user is one option. VThile this would provide

direct traceability , the disadvantage of physical distance

from the user could cause serious time delay and transportation

problems . NBS would be unable to handle the increased volume

of services without a significant change in both its resources

and the nature of its programs.

Another option would be to use existing DOE and DOD

radiation laboratories. These are well equipped and regionally

distributed. However, neither agency has as its mission the

provision of measurement and calibration service on a general

basis, nor is there traceability to a common set of national

standards in all areas.

Some Federal regulatory agencies currently provide some

calibration and measurement quality assurance services to

users. These services might be expanded to give more complete

coverage of the radiation measurement field. Again, the

regulatory agencies do not have the provision of measurement

and calibration services as their general mission and calibrating instruments for regulatees may present enforcement problems

to the regulator.

Congress might support the establishment of federallysupported regional calibration facilities, either government

or contractor operated. This would solve many of the problems

described above as these laboratories would be chartered with

the specific mission of providing measurement services. The

Federal cost of this option would be higher than other possible

choices. Duplication and competition with some currently existing

private-sector services are potential problems. Additionally,

federally-supported laboratories create a dependence by the

states on the Federal government, when what is needed is a general

improvement of state capability.

Fostering increased private-sector involvement in measurement services is another option. This might be done by having

contractor-run facilities evolve into independent entities, by

X
establishing "quasi-public" corporations, or by encouraging

the private sector to expand current services . Examples of

private-sector services now in place are calibrations by

instrument manufacturers and measurement services provided by

professional and industrial groups, e.g., the regional calibration laboratories accredited by the American Association of

Physicists in Medicine and the MQA program sponsored by the

College of American Pathologists.

The last possibility to be considered here is the establis

ment of state-run regional calibration laboratories. By

sharing the expenses of operating such a facility, the states

have the opportunity to lower the costs of obtaining needed

services. The primary laboratory services would be calibrations, measurement quality assurance, and education and

training. One disadvantage is that the state-subsidized

laboratories might be competing with the private sector in

some areas. This could restrict the users of the facilities

to state and local governments. To explore this option, the

National Bureau of Standards is establishing a pilot program

with the State of Illinois for a regional calibration laboratory.

Analysis

A cooperative analysis by NBS and the CRCPD has resulted

in the identification of actions that should be considered for

improvement of the measurement support system. These actions

are of two types - programmatic and institutional.

Programmatic actions can be considered for medical, occupational, and environmental radiation measurement:

°For personnel monitoring, the greatest need is for measure

ment quality assurance at the field level.

"Occupational radiation survey measurements could benefit

from development of a wider range of national standards,

criteria for interactions between the intermediate level

and NBS, and development of continuing MQA programs.

°For radiation therapy, national standards should be

developed for high-energy x rays and electrons, and for

neutrons

"Environmental radioactivity measurements could benefit

from better-defined traceability for radioactivity

standards and cross-check samples issued by intermediate

laboratories

°For very low levels of radiation, national standards

should be developed and suitable calibrations provided.

xi
°With regard to medical diagnosis, it would be desirable

to have operational MQA programs between NBS and intermediate laboratories, followed by similar programs between

the latter and those making measurements in the field.

Institutional actions needed for improvement of the

measurement support system include the provision of more

services at the intermediate level. i °Traceability mechanisms from Federal agencies to NBS

could be improved through better interagency communications

and cooperation.

° Improving traceability to the private sector is complicated by the diversity of actors in this area, e.g.,

instrument manufacturers, radiologists, private calibration

services, etc. All levels of the measurement support

system together with the voluntary standards writing

organizations should develop measurement traceability

criteria for calibration services provided by the private

sector. Further development of calibration services, and

particularly measurement quality assurance programs, is

needed before the private-sector measurements can be

considered satisfactory.

°In the state sector, the Federal government, in cooperation with the Conference of Radiation Control Program

Directors, should foster the establishment of up to seven

state regional laboratories to provide calibrations and

measurement traceability to state radiation control

programs. The number of these laboratories and the speed

at which they could be established would be dependent on

the amount of funding available.

Summary

The most effective measurement support system would

provide those mechanisms required to ensure the continuing

adequacy of radiation measurements that are intended to provide

public safety and health. Some of the required mechanisms are

in place and functioning, but many have not yet been developed.

These weaknesses could be overcome with additional technical

programs and institutional improvements at the intermediate

laboratory level.

xii
Glossary

Absorbed Dose (D^2 : The amount of energy imparted by radiation

to matter per unit mass. Its unit is the rad, which is equal

to 1/100 joule per kilogram.

Accuracy : The degree of agreement of an individual measurement result or the average of several measurement results with

an accepted reference ("true") value or level. As used in this

report, numerical values of accuracy (2%, 5%, 10%, etc.) indicate

the deviation of the measured value from the "true" value.

Air-Cavity Ionization Chamber : A contained volume of air

usually surrounded by an air- or tissue-equivalent wall, and

provided with electrodes that collect ions produced when

ionizing radiation enters the volume. The number of ions

produced, which are manifested in a small electrical current,

is an indication of the radiation level.

Ambient Radiation : As used in this report, low-level x or

gamma radiation that is emitted by radioactive materials in

the environment or that results from manmade radiation sources.

This type of radiation generally occurs in an area to which

access is not restricted.

Area Survey: The measurement of radiation level within a

specified area or within the vicinity of a radiation source.

Calibration ( Instrument

)

: A comparison of the response of a given instrument with the response of a standard instrument

when both have been exposed to the same radiation source under

the same conditions; or the determination of the response of a given instrument when exposed to the output of a standard

source under well defined conditions. The standard instrument

is calibrated against the national standard or against a secondary standard which has its calibration traceable to the

national standard.

Dose Equivalent (H) : In general, the biological effectiveness of a given absorbed dose depends on the type of radiation

and on the irradiation conditions. In current radiation

protection procedures, an indication of the effect upon a given organ is inferred by weighting the absorbed dose in that

organ by certain modifying factors. The product of these

modifying factors and absorbed dose is called dose equivalent,

H. The special unit of H is the rem. When D is expressed in

rads, H is in rems

.

Dosimetry: The practice of measuring or evaluating the absorbed

dose, exposure, or similar radiation quantity.

^Dose is often used loosely in the field to mean either absorbed

dose or dose equivalent.

XI i 1
Environmental Radioactivity: Radioactivity that exists in the

general environment as a result of natural occurrence of

radioactive materials or as a consequence of radiation applications by mankind.

Field Level Entity : That element of the measurement support

system that functions at the level where radiation is applied

or used, and where routine measurements are necessary. This

may involve an individual instrument or person, or may involve

a laboratory with many measurement instruments and employees

.

Instrument Traceability

:

The ability to demonstrate that a particular measuring instrument or artifact standard has been

calibrated at acceptable time intervals either against the

national standard or against a secondary standard which has

been in turn calibrated against the national standard or a transfer standard.

Intermediate Level Laboratory : A laboratory equipped with

transfer standards for providing calibrations for measurers in

the field. Sometimes these laboratories provide instrument

testing, measurement quality assurance, and other services.

Ionizing Radiation : Any type of particulate or electromagnetic

radiation that, as a result of physical interaction, can cause

atoms or molecules to lose (or gain) one or more electrons

and, thereby, to become ionized. X rays, electrons, neutrons,

gamma rays, beta rays, alpha particles, and pi mesons are

examples of ionizing radiations.

Measurement Quality Assurance (MQA): Procedures which enable

a measurer to demonstrate that the total measurement uncertainty

relative to the national standard is within prescribed limits.

One of these procedures may be a performance test.

Measurement Support System : The system of technical and

institutional elements that serves as the mechanism for enabling

field measurements to be sufficiently in agreement with the

national standards

.

Measurement System : The specific combination of instrumentation

operator, and procedure used to make a particular measurement

of a radiation quantity.

Measurement Traceability : The ability to demonstrate on a

continuing basis that the measurement results from a particular measurement system are in agreement with comparable

measurement results obtained with the national standard within

a specified uncertainty.

Millirem (mrem) : See rem.

National Standard : Artifacts, such as well-characterized

instruments or radiation sources, that embody international

definitions of primary physical measurement standards for

national use.

xi V
National Standards Laboratory : The laboratory which maintains

the national measurement standards, such as the National

Bureau of Standards in the United States

Nuclide: A species of atom characterized by its mass number,

atomic number, and nuclear energy state, provided the mean

life in that state is long enough to be observable.

Occupational Radiation Survey : The measurement of radiation

level within the vicinity of a radiation source for protection

of workers from possible radiation hazards.

Personnel Monitoring : The measurement of the amount of radiation

to which a person has been exposed by means of a small measurement

instrument worn or carried by that person.

Person-RemsThe product of the average individual dose in a population times the number of individuals in that population.

Precision: The degree of reproducibility with which a measurement IS performed.

Radionuclide: A radioactive nuclide.

Radiopharmaceutical : A radionuclide usually contained in a

pharmaceutical preparation that is administered internally to

the human body for the purpose of medical diagnosis or therapy.

Rem: The unit of dose equivalent. The dose equivalent in

rems is numerically equal to the absorbed dose in rads multiplied

by the quality factor and any other necessary modifying factors.

(Originally derived from roentgen equivalent man. ) A millirem

(mrem) is 1/1000 of a rem. (See also person-rem .

Standard Reference Material : A well-characterized reference

material generally used for calibration of a measurement system,

or for development or evaluation of a measurement method.

TraceabilityThe systematic process (or set of processes)

whereby a quantity is measured in terms of an appropriate

reference measurement standard which serves as a national

standard. (See also instrument traceability, measurement

traceability. ) Transfer Standard: A physical measurement standard which is

calibrated by direct comparison with the national standard.

A transfer standard is typically a high-quality measurement

instrument or a radiation source.

Uncertainty: An estimate of the limits of the total amount of

inaccuracy m a measurement or series of measurements. The

total uncertainty consists of both random and systematic

uncertainties

XV
Organizational Abbreviations

AAPM - American Association of Physicists in Medicine

ANSI - American National Standards Institute

BIPM - Bureau International des Poids et Mesures

BRH - Bureau of Radiological Health

CRCPD - Conference of Radiation Control Program Directors

DOD - Department of Defense

DOE - Department of Energy

EPA - Environmental Protection Agency

ISO - International Organization for Standardization

ICRP - International Commission on Radiological Protection

ICRU - International Commission on Radiation Units and Measurements

NBS - National Bureau of Standards

NCI - National Cancer Institute

NCRP - National Council on Radiation Protection and Measurements

NRC - Nuclear Regulatory Commission

OSHA - Occupational Safety and Health Administration

XV i
Requirements for an Effective National Ionizing Radiation

Measurements Program

1 . Statement of the Problem

Reliable measurements have been demonstrated for only a fraction of the ever-increasing uses of ionizing radiation!^

and for human exposures to this radiation.

Adequate accuracy is achieved when field measurements

are in agreement with national physical measurement standards

to within specified limits. To achieve and document this

needed agreement, field measurements must be traceable to the

national standards through calibrations and measurement quality

assurance tests. The United States currently lacks the means

to achieve these calibrations and measurement quality assurance

goals in key areas of radiation measurement. In other areas

for which there are already agreement mechanisms, these mechanisms may need further refinement.

1 . 1 Pervasiveness of Ionizing Radiation

1.1.1 Naturally-Occurring Sources

Mankind is continuously exposed to a number of natural

sources of radiation. In fact, all life has evolved in the

presence of radiation. These natural sources include: cosmic

rays; electromagnetic and charged particle radiation from the

sun; and radioactive materials found in the earth's biosphere

As indicated in Figure 1-1, natural sources make the largest

contribution to the average whole-body radiation dose in the

United States. The actual dose of ionizing radiation received

by individuals varies with geographic location [NCRP - 1975],

but averages over 100 mrem/Y

Exposure to natural sources is generally uncontrollable,

but does not appear to be a biological hazard unless the

radionuclides contained in the earth are redistributed or

concentrated by human activity or technology. Actions that

enhance naturally-occurring radiation include mining operations, well drilling and development, burning of fossil fuels,

and the use of construction materials (e.g., granite, brick,

concrete block) containing radionuclides [Gesell - 1975]

.

1.1.2 Man-made Sources

Radiation sources developed by man include devices such

as x-ray machines and charged-particle accelerators, and

^Italicized words are defined in the glossary found following the

Executive Summary.

1
Fig. 1-1. Estimated average annual whole-body dose

rates in the U.S. (1970) [BEIR-1, 1972].

2
artifically-produced radionuclides such as those generated in

the operation of nuclear reactors, or those produced specifically

for use in nuclear medicine or industrial applications. As shown

in Figure 1-1, the total average annual dose to the public from

all man-made radiation sources is approximately 80 mrem per

person, which is less than the dose resulting from the natural

sources. Diagnostic x rays and other medical procedures make

up 90 percent of the population dose from man-made sources.

In contrast to radiation dose received from undisturbed natural

sources, the dose due to man-made sources can be effectively

controlled.

1.2 National Concern with Radiation j 1.2.1 Public Concerns with Risk

The nation's leaders and the general public are seriously

concerned about possible health hazards resulting from exposure

to ionizing radiation from man-made or naturally-occurring sources,

and from radiation administered during medical procedures.

Probably the single event which caused greatest public

concern about ionizing radiation was the accident at the

Three Mile Island nuclear power plant in Pennsylvania. It has

been estimated [TiyiI-1979] that the 2 million people who live

within a 50-mile radius of the plant received an excess aggregate

radiation dose of 3300 person-rems due to the accident. This is

equivalent to the natural background radiation dose that the same

population would be exposed to in a period of 10 days. Many of

the instruments used to measure radiation levels were subsequently

submitted to NBS for calibrations because the particular type of

radiation predominant in off-site locations was characteristically

different from the type used originally to calibrate the instruments.

The calibration results showed that most of these instruments

overestimated radiation present at Three Mile Island.

General concern about the effects of low level radiation

encountered occupationally or in the general environment has also

been increased by recent studies. Effects of low radiation

levels have been reported for workers at the Hanford (Washington)

facility of the Department of Energy [Mancuso-1977 , Kneale-1978]

and the Portsmouth naval shipyard [Najarian-1978] . Low-level

radiation's effects have prompted a number of recent studies

including a reanalysis of the Tri-state medical x-ray survey

data [Bross-1977, 1979], investigation of military personnel

exposed to atomic weapons tests, a study of the effects of fallout on children downwind from such tests [Lyon-1979] and a reexamination of atomic bomb survivors in Hiroshima and Nagasaki

[Rossi-1978] . Several of these studies indicate increased

deleterious health effects at low doses, but questions have

3
been raised about the adequacy of the measurements that were

made and the adequacy of the methodology of analysis employed

[Sanders-1978, Gertz-1978, Anderson-1978 , Reissland-1978

,

Rothman-1979, Boice-1979, and Spiers-1979]

.

The Committee on Biological Effects of Ionizing Radiation

(BEIR) of the National Academy of Sciences has reviewed its 1972

report [BEIR 1-1972] concerning the health effects of ionizing

radiation. Despite the new studies mentioned above, this group

concluded that risk estimates remain essentially the same as

those presented in the 1972 report.

A report by the Presidentially-mandated Interagency Task

Force on the Health Effects of Ionizing Radiation concluded that

inherent methodological problems may prevent scientists from

ever finding a definitive answer to the low-dose question

[Libassi-1979] . This group listed dosimetry first among these

problems

:

"It is often impossible to determine the dose received by

an individual although researchers usually attempt to

estimate it. As a result, it may be difficult to determine whether an observed response indicates a greater-thanexpected effect of a low dose of radiation or a predictable

effect of a higher-than-expected dose of radiation."

All of the above studies have one thing in common—they

attempt to relate biological effects to radiation dose. For

the results to be meaningful, it is necessary to know accurately

the dose distribution to the population under study. It is

now increasingly acknowledged that the ultimate accuracy in

determination of a dose-effect relationship rests on accurate

knowledge of the dose given to the population under study.

This knowledge can only come about through more extensive and

accurate radiation measurements.

1.2.2 Benefits of Radiation

The degree to which sources of radiation should be controlled is determined by an assessment of the benefits from

their application, balanced against the resultant risk to

public health and safety. This assessment is difficult because the risk cannot be precisely quantified, particularly

when the level of radiation exposure is low [Libassi-1979].

If the risk is overestimated, potentially beneficial radiation

applications may be foregone.

An important example of a national benefit of radiation applications is nuclear power, which currently provides over 10 percent

of the total U.S. electric generating capacity [INFO-1979].

4
This percentage is expected to increase over the next few

decades, thereby reducing our relative dependence on imported

oil

.

Substantial benefit is received from medical applications

of radiation for diagnosis and therapy. Each year, more than

150 million Americans receive medical and dental x rays. It

has been estimated [McIntyre-1979] that the number of nuclear

medicine procedures, which employ radioactive materials, has

risen from 7 million in 1975 to 14.5 million in 1979. A vast,

increase in diagnostic information has been made possible I through the use of recently-developed computed-tomography

x-ray systems (CT scanners).

Industrial radiation processing is used primarily for

curing plastics and sterilizing medical products, resulting in

improved qualities or lower costs. Since 1970, industrial

radiation processing has grown six-fold to become a billion

dollar industry (see Appendix C, which discusses this and

other selected examples of the growth and economic value of

radiation applications).

1.3 Regulation of Radiation

Regulations have been promulgated by Federal, state, and

local agencies in response to public concern about potential

hazards resulting from rapidly expanding applications of

ionizing radiation. As indicated in Table 1-1, radiation

control responsibilities in the nation are broadly distributed

among many agencies at the Federal and state level. In some

cases, the authority granted to a specific agency may be

unclear and may appear to overlap the authority granted to a different agency. At the Federal level a relatively large

number of agencies issue regulations for radiation control

under authorities specified by an increasing number of acts

[Dodge-1978]

.

Through various contracts and agreements, responsibility

for enforcing many of the Federal regulations is delegated to

state radiation control programs [AEA-1954] . This responsibility,

combined with that of enforcing a growing number of regulations

issued by states themselves, assigns to state programs a major

national role for ensuring public health and safety.

The legislative authorities under which various Federal

agencies issue specific regulations are shown in Table 1-2

[Dodge-1977, 78, 79]. Although 19 Federal agencies have been

identified which have some radiation health and safety authority,

only those agencies with major responsibility are included in

the table.

5
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itii

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ill Hi

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urn

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ill

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ii

'-hi m

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6
Table 1-2. Responsibilities and Authorities of Regulatory Agencies.

Agency Responsibi 1 ities Legislative Authorities

1. Nuclear Regulatory Commission

(NRC)

2. Department of Energy

3. Environmental Protection

Agency

5.

Department of Health and Human Services (DHHS) National Institute for Occupational Safety &

Health (NIOSH) Food and Drug Admin.

(FDA)

Dept. of Labor (DOL)

Occupational Safety and Health Admin. (OSHA)

Dept. of Transportation

(DOT)

Regulation of nuclear facilities

and radioactive materials; public

and occupational safety; oversight

of the use of radioisotopes in nuclear medicine and industry.

Ionizing and non-ionizing

radiation research related to hazards, biological effects safety

standards; regulation of contractor

faci 1 ities.

Control and monitoring of ionizing

and non- ionizing radiation in the environment; establishment of safety

and exposure standards.

Biological effects and medical

appl i cations. Occupational safety and health

standards. Protection of public from radiation

emitting electronic products, and establishment of exposure standards.

Occupational safety and health of personnel, including those working

around radiation sources.

Safety aspects of the transportation

of radioactive materials.

Atomic Energy Act of 1954

as amended. Energy Reorganization Act

of 1974.

Energy Reorganization Act

of 1974.

National Environmental Policy i Act of 1969. Clean Air Act. Federal Water Pollution

Control Act. Resource Conservation and Recovery Act of 1976. Safe Drinking Water Act. Marine Resources and Engineering Development Act

of 1966. Toxic Substances Control Act. Solid Waste Disposal Act. Marine, Protection, Research

and Sanctuaries Act of 1972. Uranium Mill Tailings Radiation

Control Act of 1978.

Radiation Control for Health

and Safety Act of 1968. Medical Device Amendments

of 1976.

Occupational Safety and Health Act of 1970.

Transportation Safety Act

of 1974.

In addition to Federal regulation, the states maintain

their own regulatory authority which in many cases is more

comprehensive. The number of state enabling acts for radiation protection regulations is over 100 [iyioats-1978] . States

can implement model regulations as provided in the Suggested

State Regulations for Control of Radiation [SSRCR-1978 ]

, with

or without modification, or they can develop the regulations

independently. It is highly desirable from the standpoint of

the regulatee that the measurement requirements of the various

Federal, state, and local regulatory agencies be consistent

with one another.

Essentially all regulations which have as their purpose

the control of public exposure to radiation hazards are stated

in terms of specific measured upper limits. Most Federal and

state agencies also support the ALARA principle, which suggests

7
that every reasonable effort should be made to maintain radiation

exposures as low as reasonably achievable. In recognition of

this, agencies which have regulatory responsibility for radiation safety are increasingly emphasizing the need for reliable

measurements. Whereas requirements for measurements of radiation consistent with national standards were formerly almost

the exclusive province of procurement contracts, such requirements are now also found in radiation regulations [CFR-1979]

.

Uniformity of measurement results is of primary importance

for conformity between the regulator and regulatee. Regulators

are increasingly concerned that their measurements may have to

be defended in a court of law (see Appendix A). Therefore,

the incentive to assure adequate measurement quality is becoming

stronger.

2 . Measurement Needs vs. Present Capabilities

Greater accuracy is needed in measuring certain types of

medical, occupational, and environmental exposures to ionizing

radiation. Field accuracy, measurement standards for selected

types of radiation, and measurement quality assurance programs

are not yet adequate in key areas

.

2 . 1 Needs for Accuracy in Radiation Measurements

The need for accuracy in radiation measurements varies

v/ith the application or situation, and to some extent with the

type of radiation. The accuracy of measurements in the field

is established by calibrations or measurement quality assurance

tests by intermediate-level or national standards laboratories

(see Section 3 for a full discussion).

2.1.1 Medical

The need for the highest accuracy in the field of medical

radiation is for radiation therapy. Here it is generally

agreed that 5 percent accuracy in absorbed dose to the tumor

is desirable [Herring-1971 ; Shukovsky-1970 ; Shalek-1976 ] . This

requires accuracy in radiation dose measurement of about 3 percent.

The additional uncertainty is due to other factors such as

patient movement, uncertainty in knowledge of the position of

the tumor, uncertainties in the depth dose curve due to body

inhomogeneities , etc. which may affect the tumor dose. The

stringent accuracy requirement is due to the rather small

difference between the radiation dosage for tumor control and

the radiation level which will unacceptably damage the normal

tissues. Regulatory requirements for accuracy are somewhat

lower, 5 percent for beam calibration of Cobalt-60 (6oco) therapy

units under NRC regulation, and 10 percent as recommended by the

Conference of Radiation Control Program Directors.

8
since diagnostic x rays constitute the greatest contribution

to the lifetime dose of the general public from man-made

radiation, it is important that sufficient accuracy be achieved.

The CRCPD and the Bureau of Radiological Health have specificed

that measurements with 10 percent accuracy are needed in the field.

Accuracy requirements for radiopharmaceuticals used for

diagnostic procedures such as brain and liver scans, and for

therapy, have been adopted by the concerned regulatory agencies,

particularly the NRC. A diagnostic dose of a radiopharmaceutical

differing from the prescribed dose by more than 50 percent, or a therapeutic dose differing by more that 10 percent, is defined as a misadministration and must be reported and recorded. Accuracy

is needed because too high a dose will give unnecessary radiation

to the patient, while too low a dose may not yield a satisfactory

diagnostic image, requiring repeated exposures.

2.1.2 Occupational

Occupational safety measurements for ionizing radiations

frequently require accuracies on the order of 10 to 20 percent,

if the radiation level is near or above permissible dose limits.

If the levels are low, accuracies of a factor-of-two are

frequently permitted. In the case of personnel monitoring

where workers wear film badges or other kinds of dosimeters,

accuracies of the order of 30 to 50 percent are frequently

accepted, largely because of the extreme difficulty in achieving

higher accuracy in this situation where precise location of

the radiation source is frequently not known, and the orientation

of the worker's body may influence readings. Requirements are

the same, whether the worker is involved in medical, nuclear

power, or conventional industrial applications of radiation.

Whereas radiation work is generally done in some kind of

restricted area, there are always areas near radiation facilities where the public is admitted without restriction. The

permissible radiation levels in these unrestricted areas are

typically about one-tenth of those in the radiation hazard

areas . Accuracy requirements are correspondingly somewhat

relaxed due to the low radiation hazard levels.

2.1.3 Environmental

Environmental radiation measurements are generally made

in support of regulations to protect the general public from

exposure to radiation. Accuracy requirements for field measurements at levels near the regulatory limits are typically

in the range of 10 to 20 percent, relaxing to a factor-of-two

for very low level measurements such as background levels of

radioactivity in natural matrices, food and water, etc.

Monitoring of external radiation is typically done in terms of

exposure or absorbed dose, whereas for the other categories

9
activity is generally determined. For the purposes of regulation

of ingested radioactivity, activity of an identified radionuclide

is the appropriate measurement. Activity can be used with

internal dose models to estimate the dose to the affected

organs in the body.

2 . 2 Comparison of Needs with Capabilities

In Appendix B, a table of information is presented detailing accuracy needs in state radiation control programs as

developed by the Conference of Radiation Control Program

Directors (pp. B-11 to B-23). This and other information is

summarized in Table 2-1, 2-2, and 2-3. Typical accuracy

requirements are indicated in these tables for medical radiation measurements, occupational radiation measurements, and

environmental radiation measurements. In the following

sections we shall discuss the tables and the implications of

the information given on field measurements, on intermediate

level and NBS calibrations, and on NBS standards.

2.2.1 Medical Radiation

Radiation Therapy . In Table 2-1 are indicated some

typical accuracy requirements for four types of radiation used

in therapy: cobalt-60 gamma rays, high-energy x rays, high-energy

electrons, and fast neutrons. A measurement assurance test of

cobalt-60 therapy units in hospitals carried out by the National

Bureau of Standards and the Bureau of Radiological Health

found 83 percent of respondents within 5 percent of the accepted

value, but 5 percent of the respondents more than 10 percent

away from this value [Soares-1978 ] . A study conducted by the

Nuclear Regulatory Commission yielded comparable results

[Dicey-1978] . As can be seen from the table, a requirement of

3 percent accuracy in the field requires an accuracy of about

2 percent at the intermediate level, and requires an accuracy

for the NBS national standard of about 1 percent. Cobalt-60

radiation therapy dosimetry is in a nearly satisfactory state.

NBS calibrations and standards, and the intermediate level

calibrations, which are provided by three American Association

of Physicists in Medicine Regional Calibration Laboratories

and by the Radiological Physics Center in Houston, Texas under

National Cancer Institute (NCI) sponsorship, provide acceptable

accuracy for those who use their services [Golden-1972 ] . What

is presently needed is one additional regional calibration

laboratory on the west coast, and measurement quality assurance

on a continuing basis to help hospitals which are not meeting

the required accuracy [AAPM-1979]

.

Two large and rapidly growing methods of radiation therapy

are high-energy x rays and electrons produced by linear accelerators and betatrons. The accuracy available in radiation

therapy centers for high-energy x rays is not known. For

10
Table 2-1. TYPICAL ACCURACY REQUIREMENTS FOR MEDICAL RADIATION

Kind Intermediate NBS NBS

of Radiation Field Level Calibration Cal ibration Standard Measurement Accuracy Accuracy Source of Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy

Required Avai lable Accuracy Required Available nvd 1 1 dU 1 c

D on 1 1 1 v^D ri r\ V d 1 I dU 1 c Requirement

Dosimetry Co Y 3%^ <5%, 83%^ Herring and 2% 2-3% 1.5% 1-2% n <i%

for 5-10%, 12% Compton, 1971; radiation >10%, 5% Shukovsky

,

therapy, 1970; Shalek

external High energy 3% 7 et al.

,

2% 4%*^ 1.5% 4%*^ 1% beam X 1976; NRC^ High energy 3% <5%, 60%^^ CRCPD 2% 4%° 1.5% 4%'' 1% 4%'' e- >5%, 40% n 3% 7-10% 2% Not , 1.5% Not nrpcpnt LI 1 C J C 1 1 ^ available avai lable

Medical X 10% 7 BRH 5% 5% 3% 1-2% 2% 1%

X ray, CRCPD diagnostic

Nuclear 10% <30% NRC^ 5% Not 2-5% 1.5% 2-3% 1.5% medicine (hospital

)

available

diagnostic <10% CRCPD (needed for short-lived

and (manufacturers) materials only)

therapeutic

^Good therapy practice requirement (3%) is sometimes tighter than regulatory requirement (5-10%). ^Best available is ^°Co calibration with use of absorbed dose conversion factors, C^ and C^. .Small program just starting with NCI support. The meaning of this notation is, for example, that 83% of those tested demonstrated accuracy better than 5% (12% of those tested demonstrated accuracy between 5 and 10%, etc.).

^Required accuracy of calibration measurements for teletherapy units is stated in 10 CFR 35.21 (b) (1). Accuracy requirements are implied in 10 CFR 35.41 (d), (e), and (f).

high-energy electrons NBS has provided a ferrous sulfate

dosimetry service for a number of years which has shown about

two-fifths of the respondents to be outside of a 5 percent

accuracy limit. Accuracies available at NBS and intermediate

calibration levels are not satisfactory because direct calibrations

with high energy x rays and electrons are not provided. Instead,

cobalt-60 calibration is provided with the use of absorbed

dose conversion factors for electrons and for high energy

X rays. There is about a 4 percent uncertainty in these factors,

which is the dominant uncertainty in the accuracy available at

NBS [Nahum-1976]

.

A new method for radiation therapy using fast neutrons is

being tested at about five centers in the United States . The

accuracy available is about 7 to 10 percent, as shown by two

international dosimetry comparisons, one sponsored by the

International Commission on Radiation Units and Measurements

(ICRU) and the other by the Commission of the European Communities.

This accuracy is considered unsatisfactory [ICRU-1978; Broerse1978] . Therapy centers in the United States are using similar

dosimetry instruments and are on a closer relative scale than

this [Smith-1976] . Due to the small number of centers no

intermediate level calibration laboratory is needed. NBS

11
calibrations are not available for neutron radiation therapy

dosimetry. However, a small program was started at NBS in

September 1979 with National Cancer Institute support to

develop neutron dosimetry calibration capabilities.

Diagnostic X rays . As shown in Figure 1-1, medical diagnostic X rays constitute the major source of man-made ionizing

radiation dose to the population. Calibration of the useful

beam output is required to an accuracy of 10 percent. Accuracy

available in hospitals has not been documented. The AAPM

regional calibration laboratory system has recently agreed to

permit calibration of diagnostic instruments. However, at

present, calibrations for diagnostic x-ray measurements are

provided chiefly by equipment manufacturers and the Bureau of

Radiological Health (BRH). As an example during 1979 BRH

performed approximately 250 calibrations on state-owned instruments and 380 on federally-owned instruments on active

loan to the states [Ohlhaber-1979]

.

Nuclear Medicine . Radiopharmaceuticals are used in nuclear

medicine primarily for diagnosis but occasionally for therapy.

An accuracy requirement of 10 percent for therapy and 50 percent

for diagnosis has been established by the NRC. Current

measurement assurance testing of hospitals by NBS indicates

that most report values which differ by less than 30 percent

from the NBS value. Radiopharmaceutical manufacturers who

jointly sponsor a measurement assurance program with NBS are

now nearly always within 10 percent of the NBS value. This is

a significant improvement over the situation before this

program [Cavallo-1977] . Intermediate level or regional calibration

laboratories are needed only for short-lived materials since

NBS long-lived radioactivity standard reference materials can

be used directly by the hospital or clinic. Regional calibration laboratories are not available, however, to provide

calibrations of short-lived materials such as metastable

technetium-99 (^^^^tc)- When available for the given nuclide,

NBS calibration and primary standardization accuracies are

sufficient.

2.2.2 Occupational Radiation Protection

Restricted Area Survey . As is shown in Table 2-2, accuracy

requirements for radiation surveys of restricted areas (utilized

by radiation workers but not by the general public) are typically

20 percent. The accuracies available in the field are not

known. Some intermediate level calibrations are available,

but there is no regional calibration laboratory or secondary

standards laboratory that is measurement traceable to NBS.

Some manufacturers do offer calibration services and may claim

instrument traceability to NBS. Furthermore, most field

instruments are not submitted to such secondary standards

laboratories on a regular basis. NBS calibration services and

12
Table 2-2. TYPICAL ACCURACY REQUIREMENTS FOR OCCUPATIONAL RADIATION PROTECTION

Kind Intermediate NBS NBS

of Radiation Field Level Calibration Cal ibration Standard Measurement Accuracy Accuracy Source of Accuracy Accuracy Accuracy Accuracy Accuracy Accuracy

Fxcl^U 1 1 cU nv a I I du 1

c

Required Avai lable Required Avai lable Required Avai lable Requirement

x,Y 20% NRC^ and 5% Not . 3% 3% 2% 2% Restricted CRCPD avai lable area

survey p 20% NRC and 5% Not . 3% Not 2% Not CRCPD aval lable avai lable avai lable

n 20% 7 NRC 5% Not 3% Vari es^ 2% ,, • a Van es avai lable

a 20% 7 CRCPD 5% Not . 3% 2%

(airborne) available

x.Y

jT" 30-50%° 33%^ ANSI 5-7%^ Not . 3% 3% 2% 2% Personnel within Draft aval lable monitoring spec. National Standard 30-50%^ 59%^ ICRU, Not

^ 3% Not 2% Not within NCRP, avai 1 abl

e

aval 1 abl

e

avai 1 abl

e

spec

.

n 30-50%'' 36%^ Not . 3% w a Vanes 2% Varies^

within avai lable

spec.

Unrestricted x 20% 7 CRCPD 10% Not , 5% 3% 3% 2%

area avai lable survey

For neutron sources useful for checking normalization, of instrument readings accuracy available is 2% for calibrations, 1.2% for standard. Reactor beam monoenergetic neutron (2 keV, 25 keV, 144 keV) accuracies are both 10%. Van de Graaff monoenergetic beams are available 0.2-1.2 MeV with calibrations accuracy of 5%; j^standard, 2%. Monoenergetic neutron beams are needed to check energy response of instruments. ^At values small compared to the permissible limit, factor-of-2 accuracy is permitted.

jBased on ISO standard.

No calibrations are available from measurement traceable intermediate level laboratories. ®The number shown is the percent of participants who performed within specifications during a pilot test

^of a draft American National Standard.

NRC Regulatory Guide 8.21 states accuracy requirements for calibration of survey instruments. ^Accuracy requirements for pocket dosimeters are stated in 10 CFR 34.33 (c).

standards are acceptable for x a^d gamma radiation. They are

not satisfactory for the case of nonoenergetic neutron calibrations

where a wider range of energies a_id higher accuracy are needed,

for beta rays where a series of higher accuracy NBS standards

is needed, nor for airborne alpha radiation where NBS has no

suitable calibration facility. Measurement quality assurance

is not available.

Personnel Monitoring . For the radiations shown, which

are the most important, accuracy requirements range from 30 to

50 percent based on a draft American National Standard prepared

by the Health Physics Society for the American National Standards

Institute (ANSI), which is in turn based on ICRU, National

Council on Radiation Protection and Measurement (NCRP) and

International Commission on Radiological Protection (ICRP)

recommendations. This requirement is relatively low because

it is not presently possible to make significantly better

measurements . Some reasons for uncertainties in the measure13
ment process are variability in dosimeter materials, poor

procedures, inherent limitations in dosimeter design, and use

of correction factors in lieu of a range of radiation sources

for dosimeter calibration. A recent performance test of

commercial personnel monitoring services in the United States

indicated that about one-third of the suppliers are within

specifications for x rays, gamma rays, and neutrons, and roughly

60 percent for beta particles (see Table 2-2). The required

intermediate level calibration accuracy as recommended by the

International Organization for Standardization (ISO) is 5 to 7

percent. This accuracy can reasonably be expected to be much

better than the actual accuracy in the field since the important

perturbing factors in the measurement situation are absent.

Intermediate level calibration laboratories are not available.

The standards situation is the same as for restricted area

surveys

.

Unrestricted Area Surveys. Accuracy requirements here

are lower than for restricted area surveys because of the very

low radiation levels in areas of public access. Accuracy

available in the field is not known, nor are suitable intermediate calibration laboratories available. NBS standards and

calibration accuracies are sufficient.

2.2.3 Environmental Radiation

Radioactivity . Typical accuracy requirements near regulatory

limits are in the range of 10 to 20 percent. The requirements

decrease to a factor-of-two accuracy at levels less than or

equal to 10 percent of the maximum permissible activity level.

Environmental measurements are difficult, frequently involving

questions of chemistry and sampling. As a result the accuracies

available as found by measurement assurance testing vary

widely as shown in Table 2-3 from uncertainties such as 5

percent to a factor-of-ten. Intermediate-level services, in

the form of radioactivity standards, are available from the

Environmental Protection Agency (EPA), but do not provide

complete coverage of the field. NBS standards and calibrations,

when available for the particular radionuclide in question,

are usually sufficiently accurate. Environmental radioactivity

standard reference materials provide a means of giving calibrations

directly to the user without going through the intermediate

level. In practice, however, because of the large number of

measurers, many standard reference materials are supplied by

the intermediate level laboratories.

Measurements of radioactivity in natural matrices such as

water, soil, and biological materials are important to establish

natural background levels and as an aid to environmental

radioactivity measurements. Since the radioactivity of these

samples is normally well below the regulatory limits, a factor14
Table 2-3. TYPICAL ACCURACY REQUIREMENTS FOR ENVIRONMENTAL RADIATION MEASUREMENTS

Kind Intermediate NBS NBS

of Radiation Field Level Calibration Cal ibration Standard Measurement Accuracy

Required

Accuracy

Available

Source of Accuracy

Requirement

Accuracy

Required

Accuracy

Available

Accuracy

Required

Accuracy

Avai lable AccuracyRequired

Accuracy

Avai lable

External radiation

(dose)

20%^

5%

to factor

of 10 NRC,^CRCPD

10% 3% <2%^ 3%

Airborne

(activity)

«. P, Y 10%^

i%

to factor

of 10 CRCPD 5% 5% 2% <2%^ 2% <2%

Food

and water

(activity)

a, P, Y 10%^

b%

to factor

of 10 CRCPD 5% 2% <2%^ 2%

Liquids

(activity)

«. P. Y 15%^

5%

to factor

of 10 CRCPD 8% 5% 3% <2% 3% <2%

Surface

contamination,

sol ids (activity)

a, P. Y 10%^

5%

to factor

of 10 CRCPD 5% 5%'^ 2% <2%^ 2% <2%^

.Near regulatory limit. Requirements decrease to factor - of -2 well below limit. Calibrations and standards are available only for a limited energy sprectrum.

^Services are available for a limited number of gaseous radionuclides. Services are available for a limited number of radionuclides and matrices. ^Accuracy requirements for thermoluminescence dosimeters are stated in NRC Regulatory Guide 4.13.

of-two accuracy in the field is sufficient. However, the

measurement problem is extremely difficult and outlying results

are sometimes as far off as a factor of 50. A partial solution

to this problem is to use standard reference materials traceable

to NBS.

During the past few years, potential health hazards of

radiation exposure due to the presence of the radioactive gas radon in the environment and in houses have received increasing

attention. The measurement of radon and its decay products, which manifest themselves as airborne alpha and beta radiation,

is relatively difficult. Commercial availability of newer

types of instruments is limited, and calibrations provided by

commercial suppliers have been found to be unsatisfactory

[Breslin-1980] . NBS can provide only a well-characterized

radium source which produces radon, and has no standards or

facilities for calibration of the various types of instruments

used to make relevant measurements

.

External Radiation . Since the radiation levels measured

to determine the dose from external radiation in the general

environment are usually quite low (at or near normal background

levels), the required accuracy is on the order of 20 percent. Although no comprehensive performance testing of field capability has

15
been done, there is reason to believe that this level of

accuracy cannot be achieved when certain types of common survey

instruments are used. If pressurized ionization chambers are

used, the desired accuracy can be achieved when this instrument

is calibrated properly. A series of international intercomparisons of environmental thermoluminescence dosimeters showed a large variation in accuracy of participants' results. Although

intermediate level calibrations are available, they are not

always performed with a radiation source that is representative

of the energy spectrum encountered in the field. The NBS

standard and calibration capability also are not representative

of environmental field conditions.

3 . Measurement Support System

3 . 1 Necessary Elements of a Radiation Measurement

Support System

3.1.1 Measurement Standards

Primary physical measurement standards are ones which,

with certain defining relationships, fix the size of all units

of measurement. National standards are artifacts that embody

international definitions for national use. Often for more

frequent use and service, other standards called national

reference or national transfer standards are developed by the

national standards laboratory. These are compared as frequently

as necessary with the national standards. For ionizing radiation

national standards exist for the quantities of exposure,

absorbed dose, radioactivity, source emission rate, and fluence

rate. For example, a national standard for exposure is the

free-air chamber while the corresponding national transfer

standard is an air-cavity ionization chamber. The types of

ionizing radiation of most interest for measurement in the

medical, occupational, and environmental areas are x rays, y

rays, p particles, a particles, electrons, and neutrons.

Establishment and maintenance of a national ionizing radiation

standard usually involves an instrument used in conjunction

with a well-characterized radiation source.

3.1.2 Calibrations

Transfer standards provide a measurement reference basis

where it is needed and used. These standards are compared to

the national standards or national reference standards. The

process of comparison constitutes a calibration . When transfer

standards are calibrated and returned to an intermediate

laboratory, a factory or other local laboratory, they become

the basis for calibration of local working standards or field

instruments. Instruments calibrated against these transfer

16

I
standards are said to be instrument traceable . Concepts

fundamental to calibration of a standard and its use are

accuracy , precision , and uncertainty (see Appendix B, p. B-7).

Accuracy is the degree of agreement of an individual measurement or the average of several measurements with an accepted

reference value or level, and precision is the degree of mutual

agreement among individual measurements under defined conditions.

The uncertainty of a measurement is usually taken as a combination

of the random and systematic errors associated with the measurement.

3.1.3 Field Instruments

Working instruments for measurements by scientists, technicians, inspectors, or regulators at a local site of interest

are called field instruments. These instruments are calibrated

against transfer standards maintained by a local laboratory or

sometimes at an intermediate standards laboratory. Field

instruments can often be tested and adjusted by the application

of a known, associated quantity. For example, some ionizing

radiation measurement instruments may be tested by applying a

known voltage to their associated electrical circuits and

their readout adjusted accordingly. Desirable properties of

field instruments are that they be simple to calibrate, maintain,

and use, and also be portable and rugged.

3.1.4 Data Analysis and Recording

Essential to valid interpretation and, when necessary,

comparison of measurement data is that all data be recorded

properly and analyzed by acceptable statistical techniques.

Accuracy and/or precision and uncertainty of measurements

should be reported when appropriate. Records of the conditions under which measurements were made are also essential.

This makes possible the proper identification of inconsistencies, errors, and significant changes in the data. On some

levels, measurement data analysis and evaluation can lead to

standard reference data. Such data are important in developing and maintaining measurement standards. In addition, these

data, along with other associated measurement data on the

interaction of ionizing radiation with matter, serve as the

basis for mathematical models for calculating the effects of

ionizing radiation. Direct measurement of certain physical

quantities is impractical under some conditions and must be

based on calculations involving other, related phenomena.

These calculated values become the basis for interpreting the

conditions and effects of a particular ionizing radiation

environment.

17
3.1.5 Measurement Quality Assurance

Measurement quality assurance is a procedure that enables

a measurer to demonstrate, for example by measuring an accurately

known quantity (unknown to the measurer), that the total measurement uncertainty relative to national standards is within

prescribed limits. Measurement quality assurance is necessary

on both a national and an international level . Periodic

comparisons should be made between nations of their national

standards, and between national and international primary

standards. These comparisons assure that particular national

standards satisfactorily define the internationally agreed

upon units of measurement to a sufficient level of accuracy.

Within a nation, continuing measurement quality assurance

testing of intermediate standards laboratories and of field

measurements can assure that measurements are sufficiently

accurate for their intended purpose. Such measurements on the

local level are said to be measurement traceable when they are

demonstrated to be consistent with measurement results obtained

with national standards. Measurement traceability is a rigorous

test of the measurer's overall capability including performance

of the instrument and personnel, and adequacy of procedures.

For this reason it is much more desirable than instrument

traceability which by itself does not assure correct

measurements

.

3.1.6 Documented Procedures

Accurate and traceable measurements often depend on the

development of written standards or procedures that include:

definitions; compilations of reference data; data recording

and analysis; calibrations; recommended measurement practices;

and test methods. Such written standards are prepared by

voluntary consensus organizations, professional societies,

instrument manufacturers, and governmental organizations.

These documents should take into account the needs of those

who will apply them in practice, and thus, ideally should be

developed in cooperation with or open to comments by users

before implementation or adoption.

3.1.7 Research and Development

In order to improve the accuracy of national and transfer

measurement standards and improve the accuracy of the traceability path, a vigorous program of research and development must

be supported. New knowledge, scientific data, and technical

innovations in scientific instrumentation make possible continual,

improvements. An example of this is the semiconductor detector

technology which revolutionized both radiation measurement and

standardization. Research and development are usually performed

at national standards laboratories, specialized scientific and

technological institutions, universities, and private industry.

18
Activities usually cover areas larger than physical standards

development and include test methods and all applications of

measurement science and technology.

3.1.8 Education and Training

To develop the knowledge and skills needed to maintain competent measurement systems, education and training must occur on

all levels. Errors found in measurement quality assurance testing

can frequently be associated with inadequate education or training

Specialized courses are essential for disseminating the basic procedures needed for an in-house quality assurance program that guar

antees adequate continuous performance between periodic tests.

On some levels, education and training are needed on a long-term

basis, while on other levels specialized seminars, workshops, and

short-term training courses are sufficient. Intermediate or

regional calibration laboratories often serve an educational or

training function.

3 .2 Institutional Structures for Measurement Support

The accuracy of field measurements of ionizing radiation

is supported by reference to intermediate level laboratories.

These intermediate level institutions in turn depend on national

standards laboratories (such as the NBS in the United States)

to keep their instruments and measurement standards comparable, as shown in Figure 3-1.

3.2.1 International Standards Laboratories

In 1875, an international treaty called the "Treaty of

the Meter" was established to define and maintain basic measurement standards. At present, over 40 nations, including

the United States, are signatories of this treaty [NBS-1977].

Measurement standards are maintained at the Bureau International

des Poids et Mesures (BIPM) located at Sevres, France. The

BIPM serves as a center for comparison of national standards

of measurement with international standards, and coordinates

information exchange on measurement units and on progress in

research and development on measurement science.

3.2.2 National Standards Laboratories

The National Bureau of Standards develops and maintains

the national measurement standards for the United States. It

also represents the U.S. in international deliberations and

comparisons of measurement standards. Other comparable national

laboratories are:

° National Research Council of Canada

° National Physical Laboratory (United Kingdom)

° Physikalisch-Technische Bundesanstalt (Federal

Republic of Germany)

19
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The national standards laboratories serve as a reference for

standards needs for governmental agencies, industries, and

other relevant sectors of the national economy. In some

nations, they have regulatory responsibilities. This is not

the case for NBS in the United States.

3.2.3 Intermediate Level Laboratories

Intermediate standards laboratories are normally equipped

with transfer standards and provide calibrations, and they

sometimes provide measurement quality assurance and other

services to measurers in the field. Intermediate standards

laboratories are often convenient sources of education and

training for field measurers, for example by observing the

calibration or through short courses. These laboratories

should be measurement traceable to NBS

.

Advantages of inserting intermediate-level laboratories

between the national standards laboratory and users in the

field include: (1) ability to provide services to large

numbers of users; (2) intermediate-level laboratories are

often closer to users and can give faster service; (3) training of field measurement personnel is often more convenient;

and (4) with regional intermediate-level laboratories, programs

can be adapted to the needs of the region. However, the gains

achieved by introducing intermediate-level institutions between

the primary and field levels may be lost if more than one

intermediate level is introduced, since this would allow

uncertainties in the calibration chain to increase.

For therapy applications, three intermediate laboratories

have been established under sponsorship of the American Association of Physicists in Medicine (AAPM). The Bureau of Radiological

Health, Environmental Protection Agency, and Nuclear Regulatory

Commission also maintain a limited number of intermediate

standards laboratories for carrying out their respective

regulatory responsibilities.

3.2.4 Field Level Entities

The measurement support system exists to serve the needs

of those who make measurements at the field level. These are

the ultimate measurement makers, who have the day-to-day

responsibility for ensuring the safety and health of workers

and the public. The nature of these entities varies considerably, ranging from laboratories that may have in-house capability

for testing and calibrating instruments to an individual who

possesses a single instrument. Included are manufacturers of

radiation sources, users of such sources, manufacturers of

radiation-measuring instruments, and those who enforce safety

regulations

.

21
Ideally, the adequacy of measurements at this level would

be demonstrated periodically through participation in performance

testing services provided by intermediate-level laboratories

which, in turn, provide a measurement traceability link to the

national standards laboratory. This is not the present situation

however, because the testing programs that would provide

measurement traceability for field-level entities are not

generally available. At this time, the predominant type of

traceability at the field level is instrument traceability,

which does not entail a demonstration of measurement adequacy.

Calibrations that provide a high degree of instrument traceability may not be available to all who make measurement at

the field level. Those calibrations that are available sometimes have questionable quality because too many intermediate

levels are involved in making the link to the national

standards

3.2.5 Voluntary Standards Writing Organizations

A number of voluntary standards writing organizations

exist both nationally and internationally. Ideally, a consensus standard is developed by inputs from representatives

of all sectors interested or affected by the use of the standard.

Written standards usually include: standard definitions,

recommended practices, test methods, classifications of materials

and specifications for products. Voluntary standards are

often incorporated in legal specifications for products and in

Federal, state and local governmental regulations. Some

international standards writing organizations important to

ionizing radiation are:

International

International

International

International

(ICRP)

International

Organization for Standardization (ISO)

Electrotechnical Commission (lEC)

Atomic Energy Agency (IAEA)

Commission on Radiological Protection

Commission on Radiation Units and

Measurements (ICRU)

National standards writing or coordinating organizations

include

The American National Standards Institute (ANSI)

American Society for Testing and Materials (ASTM)

National Council on Radiation Protection and

Measurements (NCRP)

3.2.6 Professional Societies

As part of their organization, many professional scientific

and technological societies maintain committees or task forces

22
that concentrate on standards development. One of the important

functions of some professional societies is to provide accreditation of laboratories for calibration and testing of measurement

instruments and services. Examples of such organizations that

have activities or concerns in development of voluntary standards

in the areas of ionizing radiation are:

° Conference of Radiation Control Program Directors

( CRCPD

)

° Health Physics Society (HPS)

° Institute of Electrical and Electronics Engineers

( IEEE)

° American Association of Physicists in Medicine

(AAPM)

° Atomic Industrial Forum (AIF)

° College of American Pathologists (CAP)

° American Nuclear Society (ANS)

3 . 3 Status of the Present Measurement Support System

3.3.1 Strong Points

Both the elements of a radiation measurement support

system discussed in Section 3.1 and the institutional structures discussed in Section 3.2 are basic to the measurement

support system. Many of the essential elements of the measurement support system are in place in the United States; however,

it is recognized that improvements are needed overall [see

Appendix A]. A list of strong points of the system follows:

° National measurement standards for many quantities

are established at NBS . Frequent comparisons have

been made of these standards both bilaterally and

multi-laterally with other nations that have wellestablished national standards laboratories and

internationally with those ionizing radiation standards maintained by BIPM.

° NBS provides calibration, measurement quality assurance, and consultation services to various levels

of the measurement support system. NBS also provides

educational services such as symposia, workshops,

and seminars.

° The framework is in place to support and to develop

voluntary standards writing for all areas of ionizing

radiation on both a national and international

level. For example, on the national level, the NCRP

has more than 40 published documents and 54 functioning

committees for standards review and development.

23
° Federal regulatory agencies, namely BRH, EPA, and

NRC, have established intermediate standards laboratories to be responsive to some of their regulatory

responsibilities. For example, the EPA laboratory

in Las Vegas and the Radiological and Environmental

Sciences Laboratory of the Department of Energy

(DOE) in Idaho Falls serve as intermediate-level

standards laboratories for EPA and NRC, respectively

[Ziegler-1978; Weiss-1974] . Some state and local

governments have been supported by these Federal

agencies to carry out the agencies' responsibilities

in regulation of ionizing radiation. In the Federal

sector, the Department of Defense (DOD) and DOE

provide intermediate level calibration services for

their own needs

.

° Professional societies have been active in supporting

establishment and fostering of intermediate standards

laboratories and services. Those involved include:

American Association of Physicists in Medicine

( AAPM

)

- has a program for providing accredited calibration services for instruments used in medical therapy.

Three regional calibration laboratories have been accredited by this organization: M.D. Anderson Hospital (Houston

Texas), Memorial Hospital (New York, N.Y.), and Victoreen

Instrument Company (Cleveland, Ohio). Standard instruments

and their measurements in these laboratories are traceable

to NBS. A significant part of the service of these

laboratories is also providing free consultations on

measurement and calibration problems. In addition to

these regional calibration laboratories, a Radiological

Physics Center [Shalek-1976 ] has been set up at the M.D.

Anderson Hospital. This Center is operated by the AAPM

and funded by the National Institutes of Health through

the Committee for Radiation Therapy Studies. The Center

is conducting a measurement quality assurance program for

the ionizing radiation dosimetry practices of approximately

200 participating hospitals.

Atomic Industrial Forum (AIF) - has a cooperative program

with NBS m the area of radiopharmaceuticals. A research

associate program has been established by AIF at NBS.

This program provides a mechanism whereby NBS supervises

a radioactivity measurement quality assurance program for

the radiopharmaceutical industry [Colle-1976 ; Cavallo-1977]

.

At present, seven major commercial radiopharmaceutical

manufacturers are participating. NBS also has currently

an interagency agreement to provide similar services to

the Food and Drug Administration.

24
College of American Pathologists (CAP) - also has a cooperative program with NBS m the area of radiopharmaceuticals. The Nuclear Medicine Subcommittee of CAP in

cooperation with NBS provides a radiopharmaceutical

measurement quality assurance program for subscribing

hospitals, clinics, and nuclear pharmacies [Cavallo-1977]

.

Under CAP sponsorship, NBS distributes radioactive samples

twice a year for identification and assay to approximately

50 to 100 participating laboratories.

3.3.2 Weak Points

Although many of the basic elements of the measurement

upport system for ionizing radiation are in place, a number

f serious deficiencies exist:

° As pointed out in Section 2 of this report, national

measurement standards maintained by NBS are not

adequate in the areas of (1) dosimetry required for

the use of high-energy x rays, high energy electrons,

and fast neutrons in radiation therapy; (2) monitoring

of occupational exposure to neutrons and beta rays;

and (3) measurement of low-level radiation in the

general environment. As a result NBS is unable to

provide calibrations in these areas.

° Instrument calibrations and measurement quality

assurance services are not available to all who need

them at the field level . Only a few accredited

intermediate-level laboratories exist at this time, , and they cover limited areas of need. A pressing

need appears to be for intermediate laboratories to

provide a broad range of services to state and local

regulatory agencies. These agencies have primary

responsibility for detecting and monitoring radiation

in the interest of public health and safety, and

demands on them are increasing both in terms of

quantity and quality of their measurements [Parrott-1976 ]

.

° Instruments available for use at the field level are

in some cases inadequate for the intended purpose.

This is particularly true for measurement of beta

and neutron radiation. Needed improvements include:

less dependence of instrument response on radiation

energy; better response to short-pulse radiation;

more adaptability to automated calibration; better

reliability; capability to analyze the radiation

energy spectrum; and reduced effects from extraneous

environmental factors. Standardized performance

specifications for field instruments are not generally ^ available, nor is the capability to conduct definitive

tests of instrument performance.

25
° Although a number of regulations require instrument

calibrations, there is no accompanying guidance with

regard to what constitutes an acceptable calibration

and no recommended procedures for achieving it. In

addition, there are in general no documented criteria

for adequate performance of intermediate calibration

laboratories. Ideally, such criteria would specify

procedures for the achievement and maintenance of

demonstrated traceability to national measurement

standards . Voluntary consensus standards writing

organizations are a logical source of such procedures and criteria.

° Another serious deficiency in the measurement support

system is the lack of adequate education and training

(see appendix A). This is another example where the

magnitude of the need - many thousands of technical

personnel-cannot be met at the national standards

laboratory level but could very well be handled by

intermediate standards laboratories which could best

supply most of the training urgently needed at the

field level. Inclusion of radiation measurement

science in university curricula might contribute to

the solution of this problem.

° Measurement quality assurance services are not

available to the extent desirable at the field level

(see Tables 2-1, 2-2, and 2-3). Only limited,

sporadic programs exist which serve a small fraction

of those who make routine radiation measurements.

The procedures, instruments, and reference materials

required for more extensive MQA programs, and the

institutional mechanisms needed to conduct them, have

not been developed. A crucial element for successful

MQA efforts is follow-up consultation to improve

performance, and yet such support is almost totally

unavailable

.

° There is an obvious lack of coordination of measurementrelated efforts among the various Federal, state,

and local regulatory agencies. This gives rise to

many inconsistencies and results in inefficient

application of limited resources. Improved coordination is necessary for uniform national implementation

of procedures and criteria that will enable a more ^, adequate measurement support system.

3 .4 Priorities for Improvement of Ionizing Radiation

Measurements

Clearly not every deficiency can be attacked at once.

Table 3-1 is an attempt by the NBS and the CRCPD to place

priorities on the actions which could be taken to improve each

26
Table 3-1. PRIORITIES FOR IMPROVEMENT OF IONIZING RADIATION MEASUREMENTS

NBS National Cal ibra- Standards tionsFoster

Industrial

I.L. Labs

Inte rmediate Level Establ ish Federal State Lab RCL's TraceabilityImprove

Field

Instrumen- tation

Education

&

MQA Training

Rad'n Therapy

60C0

Rad'n Therapy

Hi -En X

Rad' n Therapy

Hi -En eRad'n Therapy

n

X-Ray

Diagnosis

Nuclear Medicine

Occupational

Survey

Occupational

Survey

Occupational

Survey

n

Occupational

Survey

a (air)

Personnel Monitoring

Personnel Monitoring

Personnel Monitoring

n

Unrestricted

Area Survey

X

External Radiation

V. (dose)

Airborne

a, P. Y (activity)

Food, water,

1 iquids

a, P, Y (activity)

Surface Contam- ination solids

a, P, Y (activity)

Note: Priorities are listed in numerical order, 1 being highest. Items left blank indicate

no need for improvement or need of relatively low priority.

27
class of ionizing radiation measurement. There is a four-step

scale of priorities: 1, 2, 3, and blank. Priorities 1, 2,

and 3 have the usual meaning, and a blank indicates either no

need for action or that priority for action is low compared to

other actions

.

Table 3-1 was prepared by considering the necessary actions

for each radiation measurement class:

° Medical

° Radiation therapy (x ray, y ray, electron,

neutron)

° Medical diagnosis (x ray, nuclear medicine)

° Occupational

° Occupational radiation survei/s (x ray, y ray,

p-particle, of-particle, neutron)

° Personnel monitoring (x ray, y ray, p -particle,

neutron)

° Environmental

° Environmental radioactivity/ (airborne, food,

water, liquids, solids)

° Ambient radiation (unrestricted area survey,

external radiation)

Actions which could be taken to improve radiation measurements in each of these areas include improving field instruments, carrying out measurement quality assurance, and providing additional education and training. Actions at the intermediate calibration level could include fostering industrial

intermediate-level laboratories, establishment of state regional

calibration laboratories, and improving traceability for

intermediate-level Federal laboratories (see Section 4). At NBS

possible actions include development or improvement of calibration

services and standards.

In the next two sections various proposals for improvement

of the radiation measurement support system will be considered to

fulfill the needs indicated in Table 3-1.

4. Possibilities for Improving Measurement Traceability Through

The Intermediate Level

The measurement deficiencies discussed in the previous

section may be remedied in part through an improved institutional

structure of the measurement support system. In this section

several possibilities for improving the structure of the

measurement support system are discussed. These approaches

are not mutually exclusive.

4.1 Enlarge NBS In-House Calibration Services

The NBS has responsibility to be the source and custodian

of the national standards of physical measurement, and thereby

28
provide the country with a scientific basis for accurate

measurements. To this end, NBS maintains a number of national

radiation standards, provides various calibration and testing

services, and conducts a research program to support these

efforts and to ensure that its measurement methods are at the

state-of-the-art and meet the needs of current technology.

NBS also plays a key role as an impartial coordinator of the

consensus approach to the solution of radiation measurement

problems. Additional details may be found in a report on NBS

interactions with the entire ionizing radiation community

[Caswell-1977]

.

Although NBS has the national responsibility to develop

and maintain the basic standards of measurement, and to provide

means and methods for making measurements consistent with

them, it nevertheless has limited resources and cannot provide

detailed services directly to the thousands who routinely make

radiation measurements without a significant change in both

its resources and in the nature of its programs. Specifically,

within its present resources, NBS could not provide these

services without serious impairment of its efforts in measurement research and basic standards development.

The principal advantage of expanding the NBS calibration

services is that the traceability link would be as direct as

possible, i.e., all calibrations would be made by direct

reference to national standards. However, it is important to

recognize that for many ionizing radiation measurements maintenance of traceability currently depends on the stability of

a given instrument which has been calibrated by reference to a

national standard. The stability of these instruments is

affected by their handling, their environment, and time. Measurement quality assurance is needed to maintain the accuracy

of radiation measurements. The NBS program is based on improving the accuracy of measurements of the national standards,

improving the stability of the components of a traceability

path to reduce the need for repeated calibrations, and improving

measurement technology such that inherently more accurate

and/or more sensitive measurements can be made in the field.

It is in these areas that NBS can make the greatest contribution toward more accurate radiation measurements.

A disadvantage of this possibility is that to the field

measurer who needs calibration, the convenience of a more

accessible laboratory would often be preferable to an NBS

calibration. A local laboratory can provide faster service

(less transit time) and more direct access for consultation.

A laboratory servicing fewer customers could also provide more

personal services to the user.

4.2 Use Existing DOE and POD Laboratories

Another approach that would make use of existing facilities

and expertise is to expand the role of DOE and/or DOD laboratories

29
to provide calibration services. For example, a number of the

DOE facilities, notably some of the national laboratories

operated under contract for DOE, have extensive expertise,

developed over many years, in radiation measurements. These

laboratories are well-equipped for ionizing radiation measurements. Except in providing measurement services for DOE's own

programs, these facilities and personnel have not been utilized

for routine calibration services. This may be partly attributed

to the prohibition by 0MB on having these public-subsidized

laboratories compete with private calibration enterprises.

The advantages of using these existing facilities as

calibration laboratories are: (1) the facilities already

exist, (2) the laboratories are well located geographically

(the DOE labs, for example, are in New York, Illinois, Tennessee,

New Mexico, Washington, and California and these could be

supplemented with DOD laboratories), and (3) neither DOE nor

DOD are primarily regulatory agencies, minimizing conflicts of

interest with regulatees. This latter advantage is reduced by

the fact that both DOE and DOD are viewed by a segment of the

public as promoters of radiation applications, specifically

nuclear power and nuclear weapons.

The principal disadvantage is that neither DOE nor DOD

consider providing measurement and calibration services to

other organizations and users as part of their principal

mission. It might be that these agencies would have to divert

resources away from their primary mission to serve this function; in fact, it is not clear that such diversion is within

the legislated authority of these agencies. Furthermore, not

all of the laboratories currently have expertise in all of the

radiation measurement areas of interest, nor is there traceability to a common set of national standards in all areas. NBS

and the national laboratories do plan to strengthen their

interaction regardless of whether the laboratories are used as

generally-available intermediate calibration facilities. They

do serve as intermediate-level laboratories in a limited

portion of the Federal sector.

4.3 Regulatory Agencies Provide Intermediate Level . A number of Federal agencies have specific interests in

assuring the accuracy of radiation measurements that are

traceable to national standards [Schneider-1976] . They have

recognized the importance of having accurate measurements that

can provide protection of workers and the public from radia- / tion hazards, and that can be used to enforce the extensive

and growing number of regulations and guidelines. As a result,

they are already providing limited measurement support services

in some areas. As was mentioned earlier, the EPA runs a

quality assurance program out of the National Environmental

Research Center in Las Vegas, the NRC conducts a confirmatory

measurements program from the Radiological and Environmental

30
Sciences Laboratory of the Department of Energy in Idaho

Falls, and the BRH provides the states with calibrated instruments, personnel training and other services.

There are advantages in having regulatory agencies provide

measurement support services and in having them serve as

intermediate laboratories. First, since the measurement

interests of an agency are quite specific, they are able to

focus their resources on those calibration services and those

measurement assurance activities which are of importance to

specific regulations. For example, the NRC reference laboratory

is concerned with radioactivity standards and measurement intercomparisons for only those radionuclides that are present in the

nuclear fuel cycle, while NBS maintains a much broader measurement

capability to provide the physical basis of measurements that

go beyond specific regulatory needs. Secondly, since regulators

maintain traceability to NBS, it may be logical to utilize

these agencies as the intermediate link between NBS and the

many different radiation users. Lastly, a number of agencies

maintain laboratories which have extensive expertise developed

over many years in radiation measurement. These facilities

and personnel are a national resource which could be utilized

to a greater extent.

However, it is unlikely that all existing needs for

measurement support services could be satisfied by utilizing

the regulatory agencies as the intermediate laboratories.

Even agencies like EPA or the Occupational Safety and Health

Administration (OSHA) which have a clear role in these areas

may not support the calibration of instruments and provide

other services necessary for the implementation of their

regulatory posture, and they may seek support in this regard

from NBS and from the industry. Furthermore, the states and

other users would need to go to different agencies for each

type of calibration, with each agency maintaining traceability

to NBS. The laboratories are not regionally distributed,

requiring either travel or shipping over long distances.

Because instrument calibration is not a primary function of

regulatory agencies, long-term continuity of calibration

services may not be assured. Finally, the practice of regulators calibrating instruments for regulatees may present enforcement problems to the regulators (one can imagine a situation where a utility cited for releasing too much radioactivity

claims that an NRC-calibrated instrument was the source of

difficulty)

.

4.4 Establish Federally-Supported Regional Calibration

Laboratories

An option that would not use any currently existing

institutions is to establish federally-supported regional

calibration facilities. This facility could be either a government owned and government operated (GOGO) facility or

31
government owned and contractor operated (GOCO). In the

former case, NBS is a logical agency, although not the onlypossibility. In the GOCO case, the NBS role could be as

contract monitor.

Both the capital investment and operational funds would

probably need to be subsidized by the Federal government with

part or all of the cost recovered through fees for services.

The customer would be anyone who needs the services and who

pays a reasonable fee. Several regional laboratories could be

created, the number depending upon demand. Services could

include calibrations, measurement assurance, consultation,

education and training, instrument lending pool, and instrument

performance tests. Traceability mechanisms would be specified

by NBS, applicable to all laboratories.

Based on opinions offered during this review, (see also

Appendix A) this possibility (either GOGO or GOCO) would be

acceptable to the majority of the radiation measurement community.

It avoids essentially all questions about conflict of interest

or political sensitivity because the laboratories would be

operated by a non-regulatory organization. Long-term commitment

by the Federal government to radiation measurements and services

would ensure stability. Duplication of new facilities would

be avoided in the Federal, state, and private sectors although

conflicts with pre-existing private sector facilities would

have to be resolved.

The disadvantages include relatively high capital costs

and continuing operational costs, both covered with Federal

funds. (Some of the high capital costs might be reduced by

locating the laboratories at appropriate current or surplus

Federal facilities). Also, it could represent government

competition with private sector laboratories, including many

which are now providing some of the needed services. Additionally it creates a dependence by the states on the Federal

government, when what is needed is a general improvement of

state capability.

The GOGO case, with NBS acting as the operator, has the

same disadvantage as enlarging NBS in-house services (see

Section 4.1). In this case NBS would have expanded its mission to providing direct calibration services to all users.

4 . 5 Foster Private-Sector Intermediate Calibration

Laboratories

One interesting possibility for the above-mentioned GOCO

facilities is that they might eventually become selfsupporting or very nearly so. If that were to occur, the

Congress might want them to become independent of governmental

control (except for traceability to NBS). This could occur

32
through allowing the contractors to "buy out" the government's

interest or through the establishment of "quasi-public" corporations. Successful examples of the latter are the TVA, Comsat,

and the Corporation for Public Broadcasting. Alternately, the

GOCO step could be skipped and an effort made immediately to

establish private-sector control of the calibration laboratories.

The advantages of such private-sector control are that

the Federal research agencies could continue to concentrate on

their principal missions and the regulatory agencies would be

relieved of making calibrations for their regulatees. The

principal disadvantage is that of economic uncertainty. The

question of whether a "full service" private-sector laboratory

could make a profit must be carefully examined. Rates high

enough to ensure profitability could prevent state and local

governments from obtaining all of the necessary services. A

private-sector laboratory might be forced to abandon some

important services that were losing money to concentrate on

more profitable services. If a private laboratory declared

bankruptcy, the government might have to step in to maintain

services and insure continuity. If calibrations or measurement

quality assurance were generally required by regulations, this

would greatly improve economic viability of private-sector

intermediate-level laboratories.

There does exist at the present time some private-sector

involvement in intermediate calibrations through commercial

calibration service companies, instrument manufacturers, and

professional groups . Instrument manufacturers occupy a unique

position in the radiation measurement community since all measurements of radiation must be made with instruments. As a result, when a user suspects that there is a problem with an

instrument, the manufacturer is usually considered first for

repair and recalibration of the instrument. Most manufacturers

offer repair and recalibration services for their own instruments,

and some manufacturers will calibrate instruments from other

manufacturers. However the consensus of instrument manufacturers

is that most instruments will not be returned unless there is

obviously something wrong with them. One manufacturer estimated

that less than 10 percent of the instruments are ever returned for

repair and recalibration, and less than 1 percent are returned for

recalibration alone.

In the absence of legal requirements for traceability

,

many instrument manufacturers do not interact directly with

NBS to insure that the calibration services they offer are

closely tied to the national standards. This is clearly an

area where improvement is needed. Although instrument manufacturers provide an important role at present with their

calibrations, there are disadvantages to the user. First, the

instruments must often be shipped long distances with the

attending possibility that handling on the return route has

disturbed the calibration. Second, calibrations of different

33
instruments must go to different manufacturers. And lastly,

not all calibration services are available.

Professional and industrial groups now provide another

mode of private-sector involvement in the intermediate calibration services. Three programs serving the medical radiation

community (see Section 3.3.1) have been provided through

professional and industrial groups. These programs have been

highly successful technically and the extension of them into

other areas of radiation measurements must be considered as a possible solution. The principal drawback is that users again

must go to different institutions for different types of

services. NBS is also required to interact with many different

groups (which it has done quite successfully though this may

not be the most efficient use of its resources.) Also, present

institutions would have to greatly expand their services or

other professional groups would have to become involved in

this process.

4 . 5 Establish State-Run Regional Calibration Laboratories

State radiation control programs have the major responsibility for assuring public health and safety in the radiation

area. This requires the ability to make accurate measurements

and, in the case of their enforcement powers, to be able to

demonstrate that accuracy. Traceability to national standards

is the key to demonstrating accuracy. States can obtain this

traceability through direct interaction with NBS, from private

industry, or through a system of regional calibration laboratories. The states feel it may be undesirable, however, for

states to have their instruments calibrated by private industry,

since the states license these industries and must use the

same instruments to determine their compliance with state

regulations.

Creating regional calibration laboratories run by state

governments is attractive for several reasons. By sharing the

expenses of operating such a facility, the states have the

opportunity to lower the costs of obtaining needed services.

Through cooperation in the design of the facility, the states

can assure that the most necessary services are provided while

obtaining infrequent services through a more cost-effective

route. These laboratories can be used by the states as "centers

of excellence" for radiation measurements, e.g., the laboratories

can be used for training state employees in new measurement

techniques either through exchange programs, course offerings,

or seminars. To obtain maximum participation in such a program,

several laboratories would be needed, geographically sited so

that each state was near a laboratory. Traceability mechanisms

would be developed by a consensus procedure involving the

states, the voluntary standards writing organizations and NBS.

Another advantage of the state regional calibration laboratory

approach is that those agencies having major responsibility

34
for radiation control would be closely coupled with the required

measurement capability.

A state regional calibration laboratory, or in fact the

radiation measurements laboratory in a given state, could be

located in a state radiation control department, or in a state

metrology department, or in some other independent agency such

as a university.

One disadvantage is that these state laboratories might

be unable to supply calibrations to the private sector since

these laboratories would be subsidized by public funds and

hence should not compete with private enterprise calibration

laboratories. Additionally, laboratories located in state

radiation control departments may not with to calibrate instruments for industries they regulate, since they feel it may

present enforcement problems. In instances where no privatesector service is available, the state-run laboratories could

provide needed services.

At this time the National Bureau of Standards, in cooperation with the State of Illinois, is establishing a pilot

program for a state-run regional calibration laboratory. NBS

is supplying the capital equipment on a loan basis as an

incentive to establishing this type of laboratory. The State

of Illinois is supplying the space for the facility and the

personnel to run the laboratory.

5 . Analysis

The national achievement of demonstrably reliable radiation measurements for health and safety requires both specific

technical actions and changes in institutional arrangements

and structures to ensure adequacy and reliability for ionizing

radiation measurements. Most importantly, there is a need for

strengthening the intermediate level coupling national standards

and field users of radiation measurement.

5 . 1 Needed Programmatic Actions

For purposes of analysis the classes of radiation measurement discussed will be those listed in Section 3.4 of this

report.

From a programmatic perspective, it is useful to consider

two types of action:

A. Those programs required for interactions between NBS

and the intermediate laboratory level

B. Those programs required for interactions between

intermediate laboratories and the field level.

35
The most effective approach is first to develop those programs

that will result in improved interactions between NBS and the

intermediate level, followed by developing programs required

to link intermediate laboratories to the field level.

It is important to recognize that, in the interest of

accuracy and uniformity for all measurements made in the

United States, both types of actions should be dependent only

upon the particular radiation quantity of interest, and not on

whether the Federal, state, or private sector is involved.

For example, the actions should be identical for intermediate

laboratories in all these sectors for the particular quantity

or measurement class involved. It is also important to recognize that the ultimate objective of all programmatic actions

is to achieve measurement quality assurance at the field

level. This requires continuing demonstration of satisfactory

measurement performance, in terms of acceptable limits of

deviation from national measurement standards. However,

before such programs can be implemented by intermediate laboratories it is first necessary to assure that their performance

is sufficiently consistent with national standards. Those

actions required to achieve an acceptable degree of consistency

will be emphasized in the following discussion of each radiation

measurement group.

5.1.1 Personnel Monitoring

The need for quality assurance at the field level has

been recognized for 25 years, but no satisfactory national

program has yet been developed. Since 1973 NBS has cooperated

with the states, various Federal agencies, and the Health

Physics Society in an attempt to establish a performance

testing program for the organizations that provide personnel

monitoring services. With NBS leadership, criteria have been

developed that will form the basis of a future routine performance testing program [ANSI -1978]. As indicated in Section

2.2 of this report, a recent pilot test that utilized these

criteria showed that present performance of personnel monitoring services must be improved.

As the future national program is envisioned by the

Interagency Policy Committee on Personnel Dosimetry Performance Testing, there will be a testing laboratory (or laboratories) at the intermediate level which will continually test

the performance of personnel monitoring services. The NBS

role will be to ensure that this intermediate-level laboratory

uses procedures that maintain consistency with national measurement standards. In this quality assurance role, NBS will

periodically calibrate the radiation sources and instruments

used by the testing laboratory, and will monitor overall

technical performance.
To improve its interactions with the intermediate-level

testing laboratory NBS should develop a wider range of national

standards, particularly for beta and neutron radiation, and

related calibration services. Routine quality assurance

interactions between NBS and the testing laboratory should be

developed and documented. Training and guidance must be

provided to the operators of the testing laboratory.

5.1.2. Occupational Radiation Survey

With the personnel monitoring performance testing program

serving as a model, discussions have been held between NBS and

interested state and Federal agencies that will eventually

lead to a similar program for measurements made with portable

survey instruments. In this case, the intermediate laboratory

is that which manufactures, tests, and/or calibrates such

instruments. Present interactions between NBS and this intermediate level are limited and poorly defined.

A number of actions must be taken to achieve a satisfactory

relationship. National standards should be developed and

maintained by NBS over a wider range of radiation types,

energies, and intensities. Photon radiation fields should be

made available which are characterized in terms of their

spectra and the exposure rate at the point of interest.

Beam-type and immersion-type standardized beta radiation

fields should be established and maintained over a range of

energies, as well as monoenergetic electron fields. A standardized moderated fission field of neutrons should be added.

Using these standard radiation fields, a wider range of primary

calibrations should be provided.

Criteria should be developed for interactions between NBS

and intermediate laboratories that will provide measurement

traceability to national standards. Continuing measurement

quality assurance programs should be implemented. As required,

the technical artifacts and instruments suitable for use in

such interactive programs should be developed or adopted.

Education and training should be made available to operators

of intermediate-level laboratories.

5.1.3 Radiation Therapy

In this particular area, there is a strong need to extend

the range of NBS standards and services in response to changing

medical practice. Increased use of high-energy x rays and

electrons in cancer therapy has created a national need for

standards and calibrations for these types of radiation.

Experimental use of neutron radiation for cancer therapy

has resulted in similar needs for NBS standards and services.

Under sponsorship by the National Cancer Institute, work is

beginning in this area.

37
Measurement quality assurance is essential because the

acceptable error is relatively small for radiation therapy.

For this reason, MQA programs should be developed and implemented

between NBS and the intermediate laboratories for all radiation

quantities of interest.

5.1.4 Environmental Radioactivity

In terms of operational measurement quality assurance

programs between NBS and intermediate laboratories, this area

is relatively well under control. Interactive mechanisms and

criteria are specified in interagency agreements with the

participating Federal laboratories. Improvements should be

considered that would allow better-defined traceability for

radioactivity standards and cross-check samples issued by the

EPA intermediate laboratory in Las Vegas.

Because follow-up consultation and training are not

available, some who participate in MQA programs at the field

level continue to perform unsatisfactorily [ Jarvis-1976 ]

This is an effective demonstration that MQA programs must be

accompanied by training if they are to be successful in improving

performance. The measurement of radon and its radioactive

decay products is a problem that must receive increased attention.

A suitable exposure chamber should be built by NBS to serve as

a national reference point for calibration of instruments that

measure the various quantities of concern (radon concentration,

radon daughter concentrations, working levels, and emanation

rates )

5.1.5 Ambient Radiation

This group of measurements is presently concerned with

low-level photon radiation that may occur naturally, may be

technologically enhanced, or may be produced by man. In

either case, the levels are sufficiently low to qualify as an

unrestricted area. Because the levels are barely above natural

background, special measurement problems are encountered. For

devices that measure dose from gamma radiation (such as thermoluminescence dosimeters) a national standard should be developed,

and suitable calibrations should be provided. When this has been

achieved, MQA programs should be implemented with intermediate

laboratories and appropriate training should be provided.

5.1.6 Medical Diagnosis

J' Whether the radiation used for diagnostic purposes is

emitted by an x-ray machine or a radioactive material administered internally, the NBS standards and calibrations are

considered to be adequate for national needs. For nuclear

medicine (radioactive materials), the existing MQA program

with manufacturers appears to be adequate but does not involve

all of them. The existing MQA program with hospitals reaches

only a small fraction of the institutions where radiopharmaceuticals

are administered to patients.

38
As mentioned earlier in this report, substantial public

exposure to radiation results from diagnostic x rays. For

this reason, it would be desirable to have operational MQA

programs that monitor measurement performance at the field

level. As a first step, NBS is beginning the development of

criteria and physical mechanisms required to establish MQA

programs between NBS and the AAPM intermediate laboratories.

When a working relationship has been established at this

level, similar programs will be developed for extending MQA

from the intermediate level to those making measurements in

the field.

5 . 2 Needed Institutional Structures and Functions

A clear need for improvement of the measurement support

system is in providing services at the intermediate level.

Although intermediate services now exist, there are obvious

gaps and weaknesses which should be remedied (see Tables 2-1,

2-2, and 2-3). Possible improvements can be examined from the

point of view of different levels of Federal involvement:

5.2.1 Current Situation

Some things can be and are being done with present resources

.

These involve no new additional Federal expenditures

.

Traceability mechanisms from Federal agencies to NBS can

be improved through better interagency communications and

cooperation, and steps in this direction have already begun.

As is indicated in Figure 5-1 the traceability in the Federal

sector is primarily instrument traceability. Additional

funding would be required to develop measurement traceability

programs

.

NBS in cooperation with state and local governments is

developing traceability mechanisms through state regional

calibration laboratories. One of these laboratories is already

being set up in Illinois and another is being planned. If

these state pilot programs are successful, host states for the

other necessary laboratories may be forthcoming. Raising the

necessary capital for equipping these laboratories remains an

impediment to establishing additional laboratories.

As indicated in Figure 5-1 some (limited) measurement

traceability reaches state radiation control departments

through, for example, the EPA Las Vegas laboratory as an

intermediary.

Some instrument traceability exists in the industrial

(non-medical) private sector through intermediate level laboratories which are privately operated. A survey is currently

being carried out by CRCPD to determine the number of these

laboratories and their functions. The laboratories do not

couple strongly nor do measurement assurance programs exist.

39
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40
Improving traceability to the private sector is complicated by

the diversity of actors in this area, e.g. instrument manufacturers, radiologists, private calibration services, and so

forth. In the case of medical radiology, several regional

calibration laboratories have been set up by the American

Association of Physicists in Medicine, a professional organization. These laboratories are measurement traceable to NBS

and provide instrument traceability to hospitals and clinics.

A study by AAPM indicates at least one additional regional

calibration laboratory is needed [AAPM-1979].

The National Bureau of Standards together with the voluntary standards writing organizations and professional societies

should develop measurement traceability criteria for services

performed in the private sector. Further development of calibration

services, and particularly measurement quality assurance

programs, is needed before private sector measurements

can be considered satisfactory. Progress will remain at a relatively slow pace unless financial support is increased.

5.2.2. Recommendation: Strengthen Intermediate

Level Institutions

An improved measurement support system, represented

schematically in Figure 5-2, would take advantage of existing

intermediate level laboratories in the Federal, state and

private sectors. New intermediate level laboratories would be

established where appropriate, and a greater emphasis put on

measurement traceability at all levels. This would ensure

that the best form of traceability is made available to field

users of radiation measurement in all sectors. In addition to

making maximum use of existing laboratories, the advantage of

the approach outlined in Figure 5-2 is that each sector has

intermediate laboratories suitable to its own needs, and to

whom the sector's field measurers of ionizing radiation can

relate effectively.

In the case of the Federal sector, intermediate level

laboratories exist in the Department of Defense, Department of

Energy, Environmental Protection Agency, Bureau of Radiological

Health, and for the Nuclear Regulatory Commission. Measurement

quality assurance programs would be needed, both for testing

the traceability of the Federal intermediate level laboratories

to NBS, and of Federal measurers to their intermediate level

laboratories. It is not likely that these laboratories in

specialized agencies would broaden their missions to serve all

sectors.

In the state sector, the Federal government in cooperation

with the Conference of Radiation Control Program Directors

should foster the establishment of up to seven state regional

calibration laboratories which could provide calibrations and

measurement traceability to state and local radiation control

41
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42
departments. The state regional calibration laboratory might

be located in the Department of Health, as are the radiation

control departments normally, or in an existing state metrology

laboratory or in other institutions such as non-profit companies

or universities. State radiation control departments could in

principle operate state regional calibration laboratories and

provide calibrations to licensees within the state or region.

However, many of them feel that this represents a conflict of

interest and would prefer that licensees receive their calibration from industrial intermediate level laboratories.

As mentioned in Section 4.6, NBS is cooperating with the

State of Illinois in the establishment of a pilot regional

calibration laboratory. It is expected to become operational

in 1981, with original capability to provide calibrations

of instruments used to measure x rays applied in medical

and industrial radiography. The capability to provide calibrations for gamma radiation, using cesium-137 as the source,

will be added in the very near future. As the laboratory

develops, it is planned to add other calibration services,

and to subsequently provide measurement quality assurance

services. It is hoped that the Illinois laboratory will be

able to subsequently provide training to other state personnel in the area of radiation measurement and calibration.

Another service this laboratory may eventually provide is

testing of instruments to determine whether state performance

specifications have been met by the supplier.

The Illinois laboratory will serve that state's needs

for measurement support services in implementation of its regulatory program, and will make its services available to other

state and local governments on a fee basis. Most state radiation control programs in that region of the country have expressed their intent to use the available services. It is expected that the State of Illinois will recover a substantial

fraction of the cost of laboratory operation from user fees.

Procedures used in this laboratory, including specific interactions with NBS, will be documented and will serve as the

basis of operational criteria for laboratories of this type.

These criteria may subsequently be used for accreditation of

this, and similar, state laboratories by the Conference of

Radiation Control Program Directors.

In this cooperative endeavor, the State of Illinois has

provided suitable laboratory space and the operational staff

required for continuing provision of services to users at

the field level . The National Bureau of Standards has provided, on a loan basis, the instrumentation and radiation

sources required in an intermediate standards laboratory of

this type. NBS also assisted in design of the laboratory and

provided training for the operator. On a periodic basis, the

instruments used as in-house standards by this laboratory will

be recalibrated by NBS and the laboratory's services will be

monitored to assure that adequate quality is maintained.

43
When a range of services is available, documented procedures are followed, and adequate quality is maintained, all the

pertinent necessary elements of the measurement support system

described in Section 3 of this report will be satisfied, and the

Illinois laboratory will then serve as an example to be followed

by other states interested in establishing similar facilities.

Two additional states. South Carolina and Washington, have already expressed their desire to develop laboratories based on

the Illinois model.

In the private sector there exist a number of private

laboratories which may be instrument companies, calibration

service companies, or in some cases not-for-profit institutions.

Work needs to be done with the voluntary standards community

and professional societies to establish criteria for the

industrial intermediate level laboratories, and to establish

measurement traceability to NBS through the industrial

intermediate level laboratories for measurers in the industrial

sector. As previously noted, in the case of the medical regional

calibration laboratories, the American Association of Physicists

in Medicine believes that one more laboratory is required.

The calibrations for diagnostic purposes are only beginning,

calibration for radiation therapy having been the primary

service provided in the past.

To accomplish all that is represented under this option

increased funding will be required. Equipment will be needed

for state regional calibration laboratories. The states and a fee system will probably provide the operating funds for these

laboratories. Measurement traceability criteria will be required

for the laboratories in the industrial sector. A very large

set of measurement quality assurance programs will be needed in

all sectors to establish measurement traceability.

The benefits of following this overall approach which is

keyed to strengthening intermediate level institutions include:

(1) the measurement traceability of field measurements throughout

the nation in each sector--Federal , state, and private; (2)

strong support for regulatory measurements done by state and

Federal regulators; (3) creation or improvement of a measurement

support system suitable for each sector with a minimum of new

institutions, the chief new institutions being the state

regional calibration laboratories.

It should be recognized, however, that a satisfactory

overall approach to the measurement support system for radiation health and safety also requires development of needed

national standards where they do not exist, and improvement of

field measurement methods in cases where current methods are

not adequate

.

As indicated in Tables 2-1, 2-2, and 2-3, the accuracy of

field measurements is frequently inadequate or unknown. The

44
ultimate criterion for judging an improved measurement support

system is the achievement of demonstrated adequate accuracy for

field measurements. NBS at present carries out a number of

measurement quality assurance programs to determine or ensure

field measurement capability. Where accuracy available in the

field is indicated in Tables 2-1, 2-2, and 2-3, this has been

determined by measurement quality assurance testing of field

measurements (measurement of an unknown radiation source or

radiation field), usually by NBS programs.

The approach suggested in Figure 5-2, which includes measurement quality assurance testing through the radiation measurement system, allows one to establish the accuracy currently

being achieved in the field. A very important feature is that

the system of Figure 5-2 is self-monitoring, providing its own

indications of the success or lack of success of the measurement support system through the results of the MQA tests. For

example, if the measurement quality assurance tests at the field

level show steadily improving accuracy, then we know the measurement situation is improving. If all MQA test results were

within the accuracy requirements as determined by regulatory

agencies or codes of good practice, then one could conclude

that the measurement support system is indeed in a satisfactory

state. If, however, field measurement performance is often

or usually worse than accuracy requirements, need for more

drastic action would be indicated.

The National Bureau of Standards could take a lead role

in bringing about a demonstrably adequate measurement support

system by developing MQA programs reaching to the intermediate

level laboratories (see Figure 5-2). It could assist the

states. Federal agencies, and industry in the development of

intermediate level laboratories in each sector, and bringing

them to a high level of competence. NBS could provide technical backup and resolution of special problems for field measurers, and provide new standards and calibrations for radiation measurements where required but not now available.

5.3 Proposed Plan for Im lementation

In this section an approach is suggested that would promote

the achievement of consistency of radiation measurement with national measurement standards through a joint effort of laboratories in the Federal, state, and private sectors. This approach builds upon the current base program at NBS which will

continue to provide essential standards and primary calibrations for low energy x rays, cobalt-60 gamma rays, radioactivity,

and pure neutron fields. The current base program also provides a modest level of measurement quality assurance and the

limited exploration of the intermediate level laboratory concept. The plan outlined below would provide a timely, comprehensive response to the most important unmet national requirements identified in this report. Additional funding would

be required to augment the base program to meet these high

priority national needs.

45
This plan would be implemented in two phases. In the

first phase new intermediate level laboratories (e.g. state

laboratories) and improved coupling of NBS with new and existing

intermediate laboratories would be established to provide a more effective mechanism for measurement support and traceability

between field users and national standards. This coupling

would be effected through standards support, measurement assurance, training, equipment loans and consultation. The second phase would emphasize the implementation of measurement

services to the field users by these intermediate laboratories

plus the long-term development of advanced measurement technology by NBS to support new types of radiation measurement.

The laboratory services would include calibrations, methods

evaluation, measurement quality assurance and training.

First year

Begin development of operational criteria for intermediate laboratories in the state and industrial sectors.

Design prototype calibration laboratories to serve as a

model for the states and industry.

Begin procurement of calibration and standards equipment

for state laboratories.

Host states begin construction of intermediate laboratories.

Provide elementary training for state and industrial personnel . Begin development of national standards for high-energy x

rays, fast neutrons, beta fields, additional monoenergetic neutrons, and photon fields.

Begin development of MQA technology and procedures to be

implemented by NBS, state. Federal, and industrial

laboratories.

Second year

Begin development of operational criteria for MQA programs

provided by intermediate laboratories to field-level

users in all sectors.

Begin providing MQA services to state. Federal, and industrial

intermediate laboratories.

States begin x-ray and gamma-ray calibrations.

State laboratories begin providing consultation to field

personnel, for instrument requirements and performance,

calibration methods, and measurement procedures.

46
Begin development of transfer standards.

Begin study of automated calibration systems.

Begin study of special measurement problems and development of field instruments.

Third year

State laboratories begin beta-ray and alpha-ray calibrations . State and industrial laboratories begin MQA services for x and gamma rays

.

State and industrial laboratories begin providing consultation and MQA procedures.

Begin providing refresher training by NBS for state and

industrial personnel.

States begin testing service for newly-procured instruments.

Fourth year

Development of operational criteria for intermediate

laboratories completed.

Procurement of equipment for state laboratories completed.

State and industrial laboratories begin MQA services for

beta and alpha rays

.

State laboratories begin providing elementary and refresher

training; NBS limits training to intermediate laboratory

operating staff.

Complete development of national standards begun during

first year. Provide calibration services against these

standards

.

Fifth year

Host states complete construction of intermediate laboratories . Development of transfer standards completed.

Study of special measurement problems completed.

47
The following activities continue into future years:

Revision of operational and MQA criteria for use

in all intermediate laboratories.

Calibration and MQA services by state, Federal,

and private intermediate laboratories.

Consultation services by NBS and intermediate

laboratories.

Training of field personnel by intermediate

laboratories.

Training of intermediate laboratory operating staff by NBS

Calibration and MQA services by NBS for state,

Federal, and private intermediate laboratories.

48
References

[AAPM - 1979] American Association of Physicists in Medicine,

"Report of the Committee on Radiation Calibration Needs

in Therapy", April 1979,

[AEA - 1954] Atomic Energy Act of 1954, as amended. Section

274.

[Anderson - 1978] Anderson, T. W. , "Radiation Exposures of

Hanford Workers: A Critique of the Mancuso, Stewart and

Kneale Report", Health Physics 35 (1978) 793.

[ANSI - 1978] Draft American National Standard Criteria for

Testing Personnel Dosimetry Performance, N13.11 (July

1978)

.

[BEIR-1 - 1972] Report of the Advisory Committee on the Biological Effects of Ionizing Radiations, National Academy

of Sciences-National Research Council, The Effects on

Populations of Exposure to Low Levels of Ionizing

Radiation , (1972).

[Breslin - 1980] Breslin, A. J., "Techniques for Measuring Radon in

Buildings", Radon in Buildings , NBS Special Publication 581,

pp. 27-35 (1980).

[Boice - 1979] Boice, J. D. , and Land, C. E., "Adult Leukemia

Following Diagnostic X-Rays?", American Journal of Public

Health 69 (1979) 137.

[Broerse - 1979] Broerse, J.J., Burger, G., Coppola, M.

,

Schraube, H. , and Zoetlief, J., "Evaluation of the

Results of the European Neutron Dosimetry Intercomparison

Project", Proceedings of the Third Symposium on Neutron

Dosimetry in Biology and Medicine, Commission of the

European Communities, Luxembourg, Document EUR 5848

(1978)

.

[Bross - 1977] Bross, I. D. J., and Nataragen, N., "Genetic

Damage from Diagnostic Radiation", Journal of the

American Medical Association 237 (1977) 2399.

[Bross - 1979] Bross, I. D. J., Ball, M. , and Falen, S., "A

Dosage Response Curve for the One Rad Range: Adult Risks

from Diagnostic Radiation", American Journal of Public

Health 69 (1979) 130.

[Caswell - 1977] Caswell, R. S., The National Measurement

System for Ionizing Radiations", NBSIR 75-946, December

1977.

49
[Cavallo - 1977] Cavallo, L., Ehrlich, M., and Hutchinson, J.

M. R., "Traceability in Ionizing Radiation Measurements

Systems", IAEA-SM-222/18 1977.

[CFR - 1979] Code of Federal Regulations, Title 10, Chapter 1,

Part 35, "Human Uses of By-product Material", January

1979, p. 35-4.

[Colle - 1976] Colle, R. , "AIF-NBS Radioactivity Measurements

Assurance Program for the Radiopharmaceutical Industry",

Measurements for the Safe Use of Radiation , NBS Special

Publication 456, pp. 71-6 (1976).

[Dicey - 1978] Dicey, B. B., Moe, H. J., and Tongue, T. M.

,

"Nationwide Evaluation of ^°Co Teletherapy Calibrations",

Medical Physics 5, 434-8 (1978).

[Dodge - 1977, 78, 79] Dodge, C. H. and McCullough, J. M.

,

"Radiation Health and Safety: Issues of Congressional

Interest", Issue Brief No. IB77062, Library of Congress,

Congressional Research Service, originated 5/16/77 (1977),

updated 7/27/78 (1978), updated 7/2/79 (1979).

[Gertz - 1978] Gertz, S. M. , "Some Major Statistical Comments

on: Radiation Exposures of Hanford Workers Dying from

Cancer and Other Causes", Health Physics 35 (1978) 723.

[Gesell - 1975] Gesell, T. F. and Prichard, H. M. , "The Technologically Enhanced Natural Radiation Environment",

Health Physics 28, 361-6 (1975).

[Golden - 1972] Golden, R. , Cundiff, J. H. , Grant, W. H. , and

Shalek, R. J., "Review of the Activities of the AAPM

Radiological Physics Center in Inter- Institutional Trials

Involving Radiation Therapy", Cancer, 29, 1468 (1972).

[Herring - 1971] Herring, D. F., and Compton, D. M. J., "The

Degree of Precision Required in the Radiation Dose

Delivered in Cancer Radiotherapy", British Journal of

Radiology, Special Report Series No. 5, Paper No. 10,

1971, p. 51.

[ICRU - 1978] International Commission on Radiation Units and

Measurements, "An International Neutron Dosimetry Intercomparison", Report No. 27, February 1978.

[INFO - 1979] INFO, published by Atomic Industrial Forum, 7101

Wisconsin Avenue, Washington, D.C. 20014, May 1979,

[Jarvis - 1976] Jarvis, A.N. , Smiecinski, R.F., and Easterly,

D.G., "The Status and Quality of Radiation Measurements

of Water," U.S. Environmental Protection Agency,

EPA-600/4-76-017 (1976).

50
[Kneale - 1978] Kneale, G., Steward, A., and Mancuso, T.

,

"Reanalysis of Data Relating to the Hanford Study of the

Cancer Risks of Radiation Workers", IAEA International

Symposium on the Late Biological Effects of Ionizing

Radiation, Vienna, March 1978.

[Libassi - 1979] Libassi, F. P., et. al. , "Report of the

Interagency Task Force on the Health Effects of Ionizing

Radiation", Department of Health, Education and Welfare

(June 1979).

[Lyon - 1979] Lyon, J. L. , Klauber, M. R., Garner, J. W. , and

Udall, K. S., "Childhood Leukemia Associated with Fallout

from Nuclear Testing, New England Journal of Medicine,

300 (1979) 397.

[Mancuso - 1977] Mancuso, T. F., Stewart, A., and Kneale, G.

,

"Radiation Exposures of Hanford Workers Dying from Cancer

and Other Causes", Health Physics 33 (1977) 369.

[Mclntyre - 1979] Mclntyre, A.B. , Bureau of Radiological

Health, private communication 1979.

[Moats - 1978] Moats, R. A. and Miller, L. A., "Report of

State and Local Radiological Health Programs Fiscal Year

1977", HEW Publication (FDA) 78-8034 (1978).

[Nahum - 1976] Nahum, A. E., and Greening, J. R. , "Inconsistency

in Derivation of C. and C„", Physics in Medicine and Biology,

21 862 (1976). ^ ^

[Najarian - 1978] Najarian, T., and Colton, T., "Mortality

from Leukemia and Cancer in Shipyard Nuclear Workers",

Lancet 1 (1978) 1018.

[NBS - 1977] The International System of Units (SI), NBS

Special Publication 330 (1977).

[NCRP - 1975] National Council on Radiation Protection and

Measurements, "Natural Background Radiation in the United

States" (1975).

[Ohlhaber - 1979] Ohlhaber, T.R., Bureau of Radiological

Health, private communication, 1979.

[Parrott - 1976] Parrott, N. W. , "State Responsibilities and

the Radiation Measurement System", Measurements for the

Safe Use of Radiation , NBS Special Publication 456, pp.

31-6 (1976).

[Reissland - 1978] Reissland, J. A., "An Assessment of the

Mancuso Study. National Radiological Protection Board",

Harwell, England, NRPB-R79 (1978).

51
[Rossi - 1978] Rossi, H. H. , and Mays, C. W. , "Leukemia Risk

from Neutrons", Health Physics 34 (1978) 353.

[Rothman - 1979] Rothman, K. J., "Review of Dr. Irwin Bross'

Presentation on Radiation Exposure and Cancer Risk",

Public Meeting of U.S. Nuclear Regulatory Commission,

April 7, 1979.

[Sanders - 1978] Sanders, B. S., "Low-Level Radiation Cancer

Deaths", Health Physics 34 (1978) 521.

[Schneider - 1976] Schneider, R. H. , "The Federal Regulatory

Agency and the Radiation Measurement System" , Measurements

for the Safe Use of Radiation , NBS Special Publication

456, 25-9 (1976).

[Shalek - 1976] Shalek, R. J., Kennedy, P., Stoval, M.

,

Cundiff, J. H. , Gagnon, W. F., Grand, W. , and Hanson, W.

F. . "Quality Assurance for Measurements in Therapy", NBS

SP456, p. Ill (1976).

[Shukovsky - 1970] Shukovsky, L. J., "Dose, Time, Volume

Relationships in Squamous Cell Carcinoma of the Supraglottic

Larynx", American Journal of Roentgenology 108 (1970) 27.

[Smith - 1975] Smith, A. R., Almond, P. R. , Smathers, J. B.,

Otte, V. A., Attix, F. H., Theus, R. B., Wootton, P.,

Bichsel, H. , Eenmaa, J., Williams, D., Bewley, D. K. , and

Parnell, C. J., "Dosimetry Intercomparisons Between

Fast-Neutron Radiotherapy Facilities", Medical Physics, 2

195 (1975).

[Soaies - 1978] Scares, C. G. , and Ehrlich, M. , "Nationwide

Survey of Cobalt-60 Teletherapy Dosimetry", NBS Technical

Note 978, August 1978.

[Spiers - 1979] Spiers, F. W. , "Background Radiation and

Estimated Risks From Low-Dose Irradiation", British

Journal of Radiology 52 (1979) 508.

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Inc., U.S. Nuclear Regulatory Commission, U.S. Environmental

Protection Agency, and U.S. Department of Health, Education

and Welfare, "Suggested State Regulations for Control of

Radiation", October 1978.

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Mile Island Nuclear Station", May 10, 1979. (U.S. Government Printing Office, Stock No. 017-001-00408-1).

52
[Weiss - 1974] Weiss, B. H. , "AEC Independent Measurements Program",

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Control, DHEW Publication (FDA) 75-8010, p. 254 (1974).

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Distribution Program: 1978-79", Environmental Protection

Agency EPA-600/4-78-033 (June 1978).

53

APPENDIX A

FINAL REPORT

TASK FORCE ON RADIATION MEASUREMENTS

CONFERENCE OF RADIATION CONTROL PROGRAM DIRECTORS

The States and Federal agencies are responsible for the protection of the

public health from the hazards associated with the use of radiation. In

order to meet this responsibility it is necessary to make radiation measurements which are accurate and defensible. Instances wherein such measurements

were made with inappropriate instrumentation, of inappropriate types of

radiation, with uncalibrated or poorly calibrated instruments, and with

inappropriate techniques are rampant and too numerous to list.

This report has been prepared by the Task Force on Radiation Measurements

of the Conference of Radiation Control Program Directors in accordance with

U.S. Department of Commerce - National Bureau of Standards Contract

No. 6-35737.

This report in its present form is divided into four sections: (1) Summary

of Recommendations, (2) Background of Task Force Activities and Personnel

during the contract period, (3) A more detailed discussion of the recommendations and suggestions for additional Task Force activities and (4) Attachments.

SUMMARY OF RECOMMENDATIONS

1. There was unanimous agreement of the need for more direct National Bureau

of Standards assistance to the States in the areas of physical standards

and measurement systems for radioactive materials and ionizing radiation.

In particular NBS should develop a mobile calibration laboratory to assist

the States in both quality assurance and training.

2. NBS should provide more standard reference sources directly to the states

at little or no cost. Specific items which are needed will be determined

and recommended in a future report.

3. NBS should review and approve all Federal guidelines, standards, and

regulations which require radiation measurements prior to the promulgation

of such guidelines, standards, and regulations to assure that such

radiation measurements are both technically feasible and practically

attainable. The Task Force should continue to review this problem during

the next contract period.

4. NBS should coordinate the development of model sampling procedures,

chemical separation procedures, and analytical measurement methods for

a variety of environmental radiocontaminants which could be used by

all State, Federal, and private laboratories to assure consistency in

the quality of the measurements.

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5. NBS in cooperation with EPA should be designated as the Federal agency

responsible for coordinating efforts among the Federal and State agencies

to immediately develop a uniform data reporting system so that present

environmental data which is being generated throughout the country can

be utilized and evaluated in terms of possible population exposures.

6. NBS should design a model calibration facility and recommend procedures

for calibration of field ionizing radiation survey instruments and

monitoring systems.

7. There is a need for additional training for all State personnel involved

in ionizing radiation measurements. Training programs should be sponsored

and supported by all Federal agencies involved in ionizing radiation

measurements. It is recommended that The Conference of Radiation Control

Program Directors establish a Task Force on Training which would, as part

of their efforts, coordinate the training activities sponsored by Federal

agencies

.

8. NBS should begin to work with specific states to resolve specific measurement problems which could be applicable to the remaining states. Such areas may include the design and operation of a state calibration facility,

calibration of specific instruments for specific types of measurement

problems, etc.

9. The present Environmental Protection Agency environmental radioactivity

laboratory intercomparison studies program provides a cross-check on individual laboratories. That program has been very successful in

identifying specific problems. However, there is presently no follow-up

program to provide assistance to those laboratories which the cross-check

program identifies as having such problems. The Task Force recommends

that the Environmental Protection Agency, the Nuclear Regulatory

Commission, the Energy Research and Development Administration, and the

National Bureau of Standards cooperate in resolving this issue.

10. The Task Force was unable, because of restrictions in time, to adequately

address all of the problems of radiation measurement. For that reason,

it restricted its area of concern to ionizing radiation measurement

systems only. In the field of ionizing radiation measurement, the Task

Force was only able to scratch the surface of the problems. It is

believed that a more in-depth analysis would be appropriate and may

alter the above recommendations. Therefore, as a final recommendation,

the National Bureau of Standards should continue to sponsor the Task

Force on Radiation Measurements in a manner suitable to both the

National Bureau of Standards and the Conference of Radiation Control

Program Directors.

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BACKGROUND OF TASK FORCE ACTIVITIES

The Task Force on Radiation Measurements was organized in 1975 by the

Conference of Radiation Control Program Directors to work with the National

Bureau of Standards in an attempt to provide input into Bureau activities

relating to state radiation measurement problems and priorities. The Task

Force consisted of six state radiation control personnel as follows:

Thomas M. Gerusky, Pennsylvania, Chairman; Marshall W. Parrott, D.Sc,

Oregon; Donald E. Van Farowe, Michigan; Ellen Haars, Ph.D., Iowa;

Richard Bleumle, South Carolina; and Paul Eastvold, Illinois. Four Federal resource personnel were assigned as follows: Roger Schneider, FDA;

Raymond Johnson, EPA; Bernard Weiss, NRC; and Sherman Fivozinsky, Ph.D.,

NBS.

An organizational meeting was held on October 22-23, 1975 at the National

Bureau of Standards. Ellen Haars was elected Vice-Chai rman and Paul Eastvold

was elected secretary. Thomas Ohlhaber replaced Roger Schneider as the FDA resource person. During that meeting, a questionnaire was designed to

determine the needs and desires of the states concerning 1 aboratory" and field

radiation measurement systems for both ionizing and non-ionizing radiation.

On February 11, 1976 a contract between the Department of Commerce and the

Conference of Radiation Control Program Directors was signed by the parties

requiring the Conference through the Task Force on Radiation Measurements to

"study radiation measurement needs and practices in the various state agencies

. . ." The Task Force was also required to file a progress report, a draft

final report, and a final report on the results of the study for NBS. The

report was to include "the problem areas discovered, the kinds of technical

and procedural activities which would serve to solve the problems, and the

proposed role of NBS in aiding implementation of these activities."

On April 6, 7, and 8, 1976, the Task Force met in Las Vegas at EPA's Office

of Radiation Programs facility to analyze the results of the questionnaire,

to visit with EPA quality assurance personnel, and to tour the EPA radiation

measurements facility. A report summarizing the questionnaire results was forwarded to NBS on April 13, 1976. (See Attachment A)

The Task Force also met during the annual meeting of the Conference of

Radiation Control Program Directors in Springfield, Illinois in May to plan

future activities of the Task Force.

A sub-group of the Task Force (Marshall Parrott and Robert Craig, Oklahoma,

a new member) were requested to visit a state radiation control laboratory

to discuss measurement needs directly with the state radiation control

program personnel. They visited the California State Health Department

laboratories on July 1 and 2, 1976.

A progress report on Task Force activities was submitted to NBS on August 10, 1976.

AThe Task Force was reconstituted by the Executive Board of the Conference

of Radiation Control Program Directors due to changes in state personnel

and resignations. Presently the following personnel constitute the Task

Force on Radiation Measurements: Thomas M. Gerusky, Pennsylvania, Chairman;

Marshall Parrott, Oregon; Robert Craig, Oklahoma; Larry McDonnell, Wisconsin;

Paul Eastvold, Illinois; and Richard Bleumle, South Carolina. Federal resource

personnel include Elmer Eisenhower, NBS; Bernard Weiss, NRC; Thomas Ohlhaber,

BRH-FDA; and Raymond Johnson, EPA.

On October 27-29, 1976, the Task Force met in Des Plaines, Illinois to

determine the content of the draft final report and to discuss future goals

of the Task Force.

On February 23 and 24, 1977, the Task Force met in Phoenix to review the

comments on the draft report and made significant changes as are incorporated

in this final report.

DETAILED DISCUSSION OF PROBLEMS AND RECOMMENDATIONS

It became very evident during the first few hours of Task Force discussions

that the problems involved in the measurements of ionizing radiation sources were of such a magnitude that the primary effort of the Task Force would be

to attempt to prioritize those ionizing radiation measurements problems and

then to recommend specific actions which could be taken to solve those

problems. The attitude of the Task Force was not that there are no serious

problems with non-ionizing radiation measurements, but that the needs of and

demands placed upon state radiation control programs were mainly in the area of ionizing radiation. Non-ionizing radiation measurements are expected to

become a more serious problem as more states become involved in this area of radiation protection.

The Task Force decision was backed up by the state questionnaire survey.

One survey reporter stated: "Let's solve our present problems before we solve our future problems." That statement epitomized the feelings of the

Task Force members.

The Task Force then wrestled with the problem of "quality assurance" versus "quality control" or instrument calibration. It was decided that the whole

radiation measurement system was in desperate need of a properly designed

and executed quality assurance program, both for low-level environmental

radioactivity or radiation measurements and higher level field survey

radiation measurements (such as x-ray output and scatter, neutron measurements

etc. ).

ENVIRONMENTAL RADIATION MEASUREMENTS

Problems involved with environmental ionizing radiation or radioactivity

measurement systems dominated the Task Force discussions, mainly because

A-4
of both the magnitude of the problems and the scope of involvement by Federal,

state and private company programs in this vital area. Both routine and

emergency measurement systems were discussed, but the Task Force concentrated

on routine measurements. Other Federal and Conference Task Forces are reviewing emergency monitoring requirements.

The states needs in environmental measurements can be summarized as follows:

a. A quality assurance program to include:

1. Sampling procedures (collection)

2. Sample preparation

3. Sample measurement

4. Data reporting

b. Additional low level laboratory standards

There is a serious need to adequately define the term "quality assurance"

as related to environmental radioactivity analysis. A recent paper by

J. Selvidge entitled "Precision of Radiation Monitoring Measurements,"

Health Physics , Vol. 30, June, 1976, pp. 479-484, discusses the problem in

general and specifically cites the example of the monitoring of ^^^Pu

concentrations in air from working areas and stacks.

Selvidge states "For measurements of levels of radioactivity to be most

useful to decision makers, some indication of the precision of the figures

obtained should be reported ... To determine the cumulative error associated

with such a measurement, the different sources of error must be identified,

the magnitude of their contributions to the error estimated, and the

propagation of the error throughout the procedure computed."

He addresses the types of error as follows: "The types of error important

in radiation monitoring can be classified into four general categories:

1. Errors arising from the mechanics of the collecting and

counting procedure;

2. Statistical variation in the phenomenon being observed;

3. Limitations on the number of significant figures obtainable

for quantities appearing in the computations; and

4. Indeterminate errors."

Selvidge' s conclusions and the conclusion of the Task Force are almost identical

although arrived at separately. Selvidge outlined a method "for identifying

sources and magnitudes of factors contributing to monitoring errors and their

propagation through the calculation of the concentration [which] enables the

A-5
analyst to determine how accurate a measurement of radioactivity is." He also

states that error can be reduced by devising specific plans once the sources

of the errors are known.

The Task Force for its purposes has defined "quality assurance" as both

a determination of the error and a program to control that error within

reasonable limits.

Within environmental radiation sampling there is a need for:

1. Universally accepted definitions of sampling procedures for

specified samples (air, water, soil, etc.);

2. A method of reporting sampling procedures;

3. A method to determine if the sample collected is a representative sample; and

4. A standard procedure for determining sampling errors.

In the sample preparation procedure there is a need for:

1. Standardized procedures (does the checmical or mechanical

procedure change the sample in such a way that one is not

analyzing what one thinks he is analyzing?)

2. Procedures for determing error (What procedures produce

uncertainties in the measurement system? For example,

how much of a specific radioisotope is lost on glass

walls, released to the atmosphere, etc. by the specific

preparation? The quality assurance program should locate

and assure that the variability in the sample preparation

technique remains within acceptable limits.)

In the sample analysis area:

Equipment should be calibrated for the type of sample being

analyzed including geometry and for specific isotopes in the

sample.

In data reporting area:

There is a need for a standardized data reporting system for

all agencies and other companies or individuals publishing

environmental monitoring results. (Claude Sill, Chief,

Analytical Chemistry Branch, Health Services Laboratory, ERDA,

recently prepared an internal document which discusses in

detail the problems with the way various laboratories report

A-6
their analytical results. He also proposes a standardized procedure

for the Health Services Laboratory. NBS, the other Federal agencies,

and the states should review this procedure for its appropriateness.

(See Attachment B)

There is a definite need for methods of calibration and suitable standards

traceable to NBS for field environmental radiation measurements. Natural

background levels of radiation are variable throughout the U.S. One

example of the problem of low-level environmental radiation is the determination of exposure from natural uranium deposits. Calibration sources

(e.g. a slab of uranium ore) are necessary to calibrate scintillation

counters, thermoluminescent dosimeters, and pressurized ion chambers so that radiation exposure levels can be accurately determined.

During the discussions concerning environmental monitoring the Task Force

agreed that the present EPA environmental radioactivity laboratory intercomparison studies program was indeed successful and that EPA should be

lauded for this activity. The program should be expanded and a follow-up

program should be started to assist those state programs where deficiencies

exist.

The Task Force also agreed on the need for a continuing program of Federal

agency cooperation and that NBS should play a greater role in this effort,

especially since the remaining agencies are mainly regulatory in nature.

In all cases, environmental radioactivity measurement systems should be

traceable to an NBS system.

It is also recognized that NBS should maintain its independence from direct

involvement in the regulatory process.

FIELD SURVEY MEASUREMENTS

Field survey measurements made by state radiation control programs may be

subject to future court actions since many of these measurements are directly

involved in the regulatory process. There is some question concerning the

accuracy requirements of these instruments.

In any case, there is a need for survey equipment evaluation, survey equipment

calibration standards and calibration procedures.

Presently, NBS does provide both equipment calibration services and reference

sources. Both of these areas should be expanded and equipment evaluation

should be included in any expanded program.

Of major concern to the states is the cost of the calibration of their survey

equipment. Present costs are too prohibitive. It is recommended that the

Federal and state agencies involved in field survey equipment calibration be

given immediate monetary relief.

A7
A major step toward relieving the states from the routine calibration cost

burden is by NBS providing a mobile calibration facility or facilities which

could assist the states in their calibration procedures. Most states polled

felt that the optimum solution for calibration would be to have their own facilities with routine back-up by NBS. Unfortunately budgetary constraints

again restrict most states from proceeding toward that goal. The NBS mobile

calibration facility would solve the problem for the near future.

Some states expressed a desire and apparently had funds to establish their

own calibration facility. The Task Force recommends that NBS develop a model calibration facility and work with those states desiring assistance

in designing and use of state facilities. In this way, NBS would benefit by

learning the problems inherent in the design and use of state calibration

facilities and solving those problems.

Specifically, the Task Force recognized problems in the field survey measurement system and cites the following examples:

1. The wide spread of x and gamma energies (from 20 keV to '^-2 MeV for

most operations) and spectra which are seen in the field;

2. The lack of neutron survey equipment and calibration standards;

3. The calibration of thermoluminescent dosimeters for both low

and high level radiation sources;

4. The need for additional alpha and beta calibration standards; and

5. The need for survey equipment evaluation and model design

specifications for survey equipment.

GENERAL COMMENTS

The Task Force also reviewed the lack of training courses and facilities for

state program personnel, specifically as it relates to the areas of radiation

measurement and quality assurance, the only areas of direct concern of the

Task Force. It is realized that the problem is greater than this, hence the

recommendation made concerning training activities.

The group also believes it necessary to continue the activities of the Task

Force and strongly supports a greater role for the National Bureau of Standards

in the activities of the Conference of Radiation Control Program Directors.

The state radiation control programs can indeed benefit greatly from more

direct contact with and support from the National Bureau of Standards. We

do not feel it presumptuous to state that the National Bureau of Standards

may also benefit from this relationship.

A-8
Areas in which further Task Force activities are desired are:

1. Determination of states instrumentation requirements;

2. Determination of the need for and kinds of accuracy required

in radiation measurements;

3. Continued assistance to NBS and other Federal agencies in

carrying out the recommendations previously made;

4. Non-ionizing radiation instrumentation and measurement needs;

5. Ultra-sound measurement needs; and

6. Maintenance of this new liaison between the states and NBS.

A-9
ATTACHMENT A

REPORT - TASK FORCE ON RADIATION MEASUREMENTS CONFERENCE OF

RADIATION CONTROL PROGRAM DIRECTORS

On April 6, 7, 8, 1976, the Task Force on Radiation Measurements of the

Conference of Radiation Control Program Directors met at the EPA Office

of Radiation Programs Facility in Nevada to analyze the results of a joint

Conference-NBS questionnaire on radiation measurement needs of the state

and local radiation control agencies.

At the time of the meeting, twenty-eight state or local agencies responded.

They were Arkansas Department of Health, California Department of Health,

Florida Department of Health and Rehabilitation Services, Illinois Department

of Public Health, Indiana State Board of Health, Iowa Department of Environmental Quality, Kansas Department of Health and Environment, Kentucky

Department for Human Resources, Louisiana Department of Conservation, Maine

Department of Human Services, Maryland Department of Health and Mental

Hygiene, Massachusetts Department of Public Health, Michigan Department of

Public Health, Minnesota Department of Health, Mississippi State Board of

Health, Nebraska Department of Health, New Hampshire State Department of

Health and Welfare, New Mexico Environmental Improvement Agency, New York

State Department of Environmental Conservation, Oregon State Health Division,

Pennsylvania Department of Environmental Resources, Philadelphia Department

of Public Health, Rhode Island Department of Health, South Carolina Department

of Health and Environmental Control, Tennessee Department of Public Health,

Texas Department of Health Resources, Washington Department of Social and

Health Services, and Wisconsin Department of Health and Social Services.

Twenty-two of the agencies responding have radioactive materials licensing

and regulatory programs, twenty-three carry out environmental surveillance

programs and twenty-seven have x-ray regulatory and inspection programs.

Fifteen of the respondents were USNRC Agreement States, eleven had USNRC

contracts for monitoring reactor effluents, eleven had FDA-BRH contracts for

monitoring electronic product radiation, and seven had OSHA contracts.

In response to the question concerning the types of NBS assistance needed,

the following types were ranked in decreasing importance:

1. (MOST IMPORTANT) To provide transfer standards to establish and

maintain traceability to NBS primary standards;

2. To prepare standard procedures for calibration of field instruments

and; to prepare standard procedures for making accurate measurements;

(tied)

3. To conduct periodic tests of measurement performance, and to provide

assistance if needed for improvement;

4. To calibrate states' transfer standards periodically against NBS

primary standards;

A-10
5. To conduct training sessions for state program personnel;

6. To provide technical assistance in evaluating measurement

instruments

7. To design a complete model state laboratory for radiation

instrument calibrations; and

8. To design a recommended calibration range for survey instruments.

The agencies were most interested in NBS transfer standards for calibrated

radioactive sources, with high interest in ionization chambers, moderate

interest in high quality survey instruments and low interest in activation

foils for measurement of neutron fields.

In response to a question concerning adequacy of field survey instrument

measurements, the majority of respondents (19) believed that gamma field

survey measurements were adequate, with a split on the adequacy of alpha,

beta and x-ray measurements. Most states (18) felt that neutron field

survey measurements needed improvement.

Twenty-six of the states (an overwhelming majority) believed that better

uniformity of measurements among the states was needed. Fifteen of the

states felt that this included all measurements, eight listed environmental

monitoring as being most important for uniformity with three states mentioning

field survey measurements.

Twenty-two of the states felt that better agreement between Federal and

State measurements was needed with eight states mentioning environmental,

and one mentioning field survey measurements. Suprisingly, five states

felt that better agreement was not needed.

Only thirteen states responded to the question that better agreement of

measurements among the federal regulators was needed with eight believing

that better agreement was necessary and five disagreeing. The "no-response"

by so many states may indicate that they did not know.

In responding to the question concerning a trend regarding needs for new

types of radiation measurements, a great variety and number of responses

were received. Non-ionizing radiation measurements headed the list, but

states mentioned needs for more environmental monitoring, emergency

radiation dose instrumentation, low-energy x rays, alpha, beta and gamma

spectrometry, thermoluminescent dosimetry, standardization of survey

procedures for x-ray equipment, nuclear reactor environmental monitoring,

and high energy particle accelerators, and radon measurements in the

field. Two states responded that we should solve our present problems

with instrumentation and measurements before we worry about future problems.

A-11
In response to the question concerning the trend regarding demand for improved

accuracy, the responses were also varied. However, the outstanding statement

was that a definition of acceptable accuracy of radiation measurements was

needed. Others included: low-level environmental monitoring for alpha, beta,

gamma, and in particular Iodine-131 and Strontium 90; accident radiation

measurement instrumentation; personnel monitoring devices; accuracy in

measurements of x-ray exposures of the public; thermoluminescent dosimetry;

and non-ionizing radiation instrumentation and calibration. Another important

statement was that the states will need to "defend" their measurements in

court cases. (A discussion among task force representatives re-enforced this

statement in that one state was then in court defending its measurements).

In response to the question "Measurement assurance programs are designed to

periodically monitor the measurement performance of a laboratory, and to

assist it in improving performance if that necessity is indicated. Would

your office be interested in participating in such a program, with NBS as a monitor?", the majority (26) responded yes .

Respondents who answered yes to the above question were asked to rank their

priorities for the type of radiation measured in a measurement assurance

program. The response in order of decreasing priority is as follows:

1. gamma environmental

2. beta environmental

3. alpha environmental

4. X radiation

5. gamma survey

6. beta survey

7. alpha survey

8. neutron radiation

In response to the question, "If you believe that a model state radiation

calibration facility is needed, what calibration capability would you like

to see included?", the response was as follows:

X-ray calibration range - 21

Y-ray calibration range - 22

TLD calibrator - 22

Reference radiation sources (rad mat) - 22

Radiopharmaceutical dose calibrator - 13

Non-ionizing radiation calibration equipment - 17

The states responded to the next question, "Are you confident that the measurements presently made by your program could be successfully defended for legal

purposes if challenged in court?", the response was as follows:

2 12 14 0

few

could

some

coul d

most

could

all

could

A-12
It is an interesting response and will be pursued further in future meetings

of the task force.

In response to the question, "Would additional ties to NBS make you more confident in defending your measurements?", the overwhelming response (26-2) was yes .

The recommended priority of measurements for which the states would like to

have recommended procedures is as follows:

1. Environmental sample counting

2. X and y radiation surveys

3. TLD monitors

4. Beta particle field measurements

5. Radiopharmaceutical dose calibrator

The recommended priority on procedures for calibrations is as follows:

1. Calibration of survey instruments

2. Calibration of counting systems

3. Calibration of TLD systems

This seems like an inconsistency with the above question, but the ranking of

priorities for 1 and 2 was very close and does not really show a serious

inconsistency.

The recommended priorities in the various mechanisms that NBS could use to

disseminate national radiation measurements standards is as follows:

1. Calibration of states' transfer standards in a mobile NBS

calibration facility which would visit each state periodically.

2. Calibration of states' transfer standards at an NBS regional

calibration facility serving a number of states.

3. Calibration of states' transfer standards at NBS site.

Twenty-five of the respondents indicated that microwave radiation was a non- ionizing measurement made in their programs, five indicated lasers, and three

indicated ultraviolet.

Thirteen respondents stated that they had legislative authority over lasers,

thirteen over microwaves, and eleven over ultraviolet radiation.

In attempting to rate the services NBS should provide regarding non-ionizing

radiation, the response was above average in all categories with ranking as

fol lows

:

1. Guidance on instrument selection

2. Training in use of measurement systems

A-13
3. Periodic test of electromagnetic radiation measurement system

4. Calibration of microwave instrumentation

5. Calibration of laser instrumentation

6. Calibration of ultraviolet instrumentation

Most states believed that in-house capability was the most desirable method

for maintaining the calibration of survey instruments, with use of external

service a low second, and return to the manufacturer a losing third.

The states responded in a variety of ways over their major concern (problems)

regarding laboratory (environmental) measurements and calibration of systems

used for this purpose. Apparently, all of the respondent's had differing

opinions on this subject. Because of the overwhelming response and the

number of problems encountered, it is obvious that serious problems exist in

all state environmental radiation laboratories. It would have been interesting

to determine if the federal laboratories had similar responses.

In response to the question, "How could NBS provide services that would help

your program find an acceptable solution to the above problem(s)?" , the answers were just as varied, but included reference standards, on-site - assistance and training, new standard methods, etc.

NBS stated in the questionnaire that six states would be involved in a joint

development phase of a mutually acceptable program and asked the states if

they had an interest in being one of those six states. Fourteen had a very

high interest, eleven had a high interest and three had a moderate interest.

The instrumentation portion of the questionnaire is very difficult to summarize.

The states possess a great variety of both laboratory and field survey instruments. A more detailed analysis will be attempted at a later date when all

questionnaires are received.

However, there are some areas of response which can be rather quickly analyzed.

In response to a question related to estimated accuracy for field surveys and

another question related to the satisfaction with the accuracy, it appears

that those respondents who believe they have ±20% accuracy or below are satisfied with that accuracy. Whether or not the estimated accuracy is correct

is debatable. In any case, sixteen respondents stated that they are satisfied

with their accuracy for inspections and surveys. Eleven respondents are not

satisfied.

In the laboratory situation, four states responded yes to the question, "Is

any energy determination made in a a-particle counting?", and twenty-three

responded negatively.

A-14
ATTACHMENT B

REPORTING OF ANALYTICAL RESULTS

Analytical Chemistry Branch

Health Services Laboratory

U. S. Energy Research

and Development Administration

There is considerable confusion in the way various laboratories report their

analytical results, particularly those from radiochemical measurements. Some

laboratories report the standard deviation resulting from measurement of the

random processes only; others report the random uncertainty after multiplication by two or three to obtain higher confidence limits. In many cases, only

the statistical uncertainty of the final sample measurement is included, while

other equally important random uncertainties incurred earlier in the determination are completely ignored. Some laboratories report various combinations

of random plus systematic uncertainties, sometimes with no clear explanation

as to what was done.

In addition to the confusion, there are other objectionable practices that

are widespread. Analytical results should be reported in such a way as to

convey as much information as clearly as possible. However, physical measurements should not be permitted to appear more precise and/or accurate than they

really are to prevent unwarranted conclusions from being drawn from the data.

For example, many laboratories report standard deviations to three or more significant figures with no more justification than "that's what the computer

gives." A standard deviation is a value by which the associated measurement

can be expected to vary once out of every three times. To infer that the

results are sufficiently precise to permit interpretation of the standard

deviation to three or four significant figures is certainly optimistic, even

if the value of the standard deviation used were correct. More often, the

value used is not even correct for several reasons: other important random

errors have not been propagated to the final result; the population distribution

is either not known or is known to be skewed; and other nonrandom (systematic)

uncertainties are present and have not been included.

Another bad practice encountered frequently is the failure to ensure decimal

agreement between the result and its associated uncertainty. For example,

results such as 1.2 ± 0.002 or 1.234 ± 0.2 are internally inconsistent and

should be clarified. Either the result is more precise than is given, as indicated by its standard deviation, and more significant figures should be

retained; or the result is much less precise than indicated, and the number

of significant figures should be decreased to agree with the precision

indicated by the standard deviation. Lack of correspondence in the decimal

places of numbers being added or subtracted frequently is responsible for

implied precision and accuracy that cannot possibly be achieved. For example,

suppose the annual release of radioactivity from several facilities was

A-15
Reporting of Analytical Results

21,200,000 curies from one, 5,260 curies from another, and 1.62 curies from a third. To say that the total activity released from the site was 21,205,261.62

curies certainly implies a precision in the measurement that is both incorrect

and unintended.

Analytical results obtained from this Branch will reflect the following criteria.

Every result will be expressed as a finite number with a pi us-or-minus uncer- tainty attached. The term "not detected" will not be used because it indicates

only that the substance in question was in fact not detected by whatever means employed but gives no quantitative information as to the sensitivity with which

it was not detected. The human eye is a much more sensitive indicator of the

size of a lump of coal than the macro scales in the coal yard. The term

"detection limit" will be used only to describe quantitatively the sensitivity

of the analytical procedures available and not to express the quantitative

results of actual analyses. The same objections and prohibition are also true

with respect to the use of other similarly quantitatively nondescripti ve terms

such as nil, none, trace, negligible, etc. Except in the absolute sense of the

last molecule, even the term "zero" is meaningless and requires quantitative

description by use of appropriate numerical values, e.g., 0.00 is certainly

different in its implication than 0.

The pi us-or-minus value attached to the result is the total statistical uncer- tainty resulting from measurement of all random processes involved, properly

carried through to the final result using the fundamental law of propagation

of errors, at the 68% confidence level (i.e., one standard deviation). The

standard deviation will be rounded off to one significant figure, or to not more than two significant figures when the numbers involved are less than 15.

For example, the number 12 has twice as many significant figures as the number

9, but an absolute uncertainty of one part in the last place produces a relative uncertainty that is not significantly different for either number.

The result itself will then be rounded off so that the last significant figure

retained will occur in the same decimal place as that in which the standard

deviation occurs. THESE NUMBERS MUST THEN BE INTERPRETED BY THE USER WITH DUE

CONSIDERATION FOR THE CONFIDENCE LIMITS DESIRED! :

An estimate of all nonrandom or systematic uncertainties incurred anywhere in

the measurement process, if significant compared to the random uncertainties,

will be placed in parentheses after the standard deviation. This estimate is

highly subjective and generally difficult, or impossible to achieve with any

substantial accuracy. However, the impressions of the analyst can be as important in assessing the accuracy and acceptability of the final result as the numerical data. Because the numerical data are more objective and

susceptible of exact statistical interpretation, the systematic uncertainties

will be kept separate so that the precision with which the measurement was carried out can be kept clearly defined.

A-16
Reporting of Analytical Results

In the past, it has been the practice of this Branch to report analytical

results at or near the detection limit somewhat indiscriminately in either

of two ways. A "less than" value such as < 6 x 10"^ yCi/ml, corresponding

to the detection limit at the 95% confidence level for the conditions used,

and the net disintegration rate actually obtained together with the standard

deviation of its determination, such as 2 ± 3 x 10"^ yCi/ml , have both been

used. Although both numbers mean almost but not quite the same thing statistically, it was thought that the practical conclusions to be obtained and the

intent would be clear from the way the data were presented. However, some confusion, loss of data, and additional problems have resulted. Particularly,

when large numbers of radiochemical results are to be combined, such as in

obtaining yearly averages, mean trends, etc., the question arises as to how

to handle results reported in terms of "less than," detection limits, or negative numbers.

In all radiochemical measurements near the detection limit, the net value

is obtained from the difference between a gross count and a background count,

which are nearly identical in size for the same counting time and which

reflect the measurement of statistically random processes. The problem is

further complicated by the fact that a net reagent blank, also near zero,

must also be determined in the same way as the net sample measurement and

subtracted therefrom. Consequently, if the sample contains "no" activity,

there is exactly the same probability of obtaining small positive net values

that are in fact "zero" as in obtaining equally small negative net values

that are "zero" because of the identical statistical probability of either

number being numerically larger than the other. The inclination to accept a small positive value as being real simply because it is positive, but to reject

an equally small negative value because it is negative is a purely human

reaction, totally unsupported by mathematical statistics when random events

are being measured. Although it is completely clear and logical that there

can be no such thing as a negative concentration, it is equally clear that

elimination of small negative numbers representing measurements of random

processes will surely give rise to a slightly positive bias in the means of

a large number of measurements.

Henceforth, it will be the policy of this Branch to report the net disintegration rate (expressed as a concentration) and standard deviation actually

obtained, whether or not the sign is negative. When the absolute value of

the net rate can be rounded off to one significant figure occurring in a decimal place to the right of the one in which the standard deviation occurs,

the value is rounded to zero. For example, 0.086 ± 0.2 is rounded upwards

to 0.09 and then to 0.10 and reported as 0.1 ± 0.2; 0.04 ± 0.2 is rounded

downward and reported as 0.0 ± 0.2. Net negative numbers should then be

rounded upwards to zero by the customer before publication or other release

after the averages have been determined, or on each individual result if

no further mathematical treatment is intended. It may be predicted with

some confidence that net negative numbers larger than two or three times

A-17
Reporting of Analytical Results

the standard deviation of the net will not be encountered. Much larger values

would give increasing confidence that the negative values were real. Because

of the physical impossibility of such a result, presence of a systematic error

in the measurement is indicated that will be identified and eliminated.

Claude W. Sill , Chief

Analytical Chemistry Branch

A-18
APPENDIX B

IONIZING RADIATION MEASURENENT CRITERIA FOR REGULATORY PURPOSES

Conference of Radiation Control Program Directors^ Inc.

Task Force on Radiation Measurements

Prepared for the National Bureau of Standards under the terms

OF NBS Contract Number 7-35787

B-l
IONIZING RADIATION MEASURErai CRITERIA

FOR REGULATORY PURPOSES

TABLE OF CONTENTS

Abstract ii

Introduction 1

Definition of Terms - The Meaning of Accuracy 3

General Discussion of Tables I - IV 6

X-Ray Measurements

Healing Arts X-ray Survey Measurement Criteria 8

Table I 9

Non-medical X-ray Survey Measurement Criteria 11

Table II 12

X-ray Measurement Problems Encountered 14

Radioactivity Measurements

Radioactive Material Measurement Criteria (Restricted Areas) 16

Table III 17

Radioactive Material Measurement Criteria (Unrestricted Areas) 18

Table IV , 19

Appendix I (for Table IV) 21

Appendix II 22

Glossary of Abbreviations and Terms 23

References 25

B-2
ABSTRACT

A number of approaches could have been made for providing the

reader with the information contained in this publication. In • the interest of brevity, it was deemed necessary to develop

definitions and tabularize the material that could be most easily

utilized by those persons enforcing certain regulatory requirements

and guides as well as those persons who are affected by the

requirements and guides. To that end, this report:

1. Defines "accuracy" which is necessary for radiation

control purposes

2. Lists pertinent regulatory criteria and limits

3. Lists the radiation sources that require measurements

4. Lists the expected ranges for those measurements

5. Lists the accuracy requirements

6. Lists the instrument considerations necessary to make

those measurements accurately

7. Discusses some of the problems and pitfalls in radiation

control measurements.

B-3
INTRODUCTION

Because of the desire of the Conference of Radiation Control Program Directors

to promote uniform radiation measurements nationwide, as well as the concern

of the Conference regarding the lack of knowledge or training of personnel

and the lack of proper instrumentation for making such measurements, the Task

Force on Radiation Measurements was established. The Task Force was given

responsibility to investigate current radiation measurement needs of state

radiation control agencies throughout the United States, and on the basis of

analysis of these needs, to suggest mechanisms by which radiation measurements might be improved such that they might be uniform nationwide. This,

then, is the basis and goal of this report. The tables summarize the results

of this investigation.

State regulatory agencies, with limited manpower, resources, and never enough

training, are required to "spread themselves thin" by making measurements on a wide variety of radiation sources and yet, at the same time, are expected to

be "expert" on each source.

The tables included in the body of this report have been developed to aid in

relieving at least a portion of this problem. They point out the typical types

of radiation measurements to be made and the reasons for making them by citing

the applicable regulatory criteria and/or guides. It is important to note that

when reviewing the regulatory criteria the ALARA (as low as reasonably achievable) concept should always be kept in mind. The range of radiation levels to

be expected when making such measurements and the accuracy with which they

should be made are also given in the tables. In addition, some of the items

which must be taken into account when selecting and using instruments are listed in the column entitled "Instrument Considerations." Because of the

limited time usually available to state personnel and the necessity to find

fast answers to problems, there are deliberate redundancies in this report to assure that those persons scanning only small portions of this document obtain

the desired information.

It is important to note that the information contained in these tables is not

"all inclusive" and is not, by any means, the answer to all problems. These

tables are a first attempt to comprehensively summarize the information and

place it into a format which can be easily utilized.

Information contained in the tables represents the current consensus, not

only of the members of the Task Force, but also of comments received from

state radiation control programs. Federal agencies, industry, health physicists,

and instrument manufacturers.

B-4
Use of the tables, as well as a continuing program for updating and

upgrading the tables by regulatory personnel and other health physics

professionals and the industry, is an important first step in promoting

uniform radiation measurements nationwide. Hopefully, we will all be

making measurements on the same basis.

In reviewing the tables, particular note should be taken of the rather wide

range of accuracy requirements. For some applications more than one accuracy

requirement is given, e.g., screening vs. verification measurements. In line

with Lauriston S. Taylor's article "A Saga of Radiation Safety" in the

May 1976 issue of NBS Dimensions, it must be kept in mind that radiation

measurements should be made, not to assure regulatory compliance for

compliance's sake, but to protect people. It is vital that we be reasonable

and rational in our requirements because different accuracies may be

appropriate for different applications. For example, an accuracy of +50%

may be appropriate for a small fraction of the occupational radiation

exposure limit, while +^10% to +20% may be appropriate for measurements at

or above the limit.

Quoting from Taylor's article, the following principles are vital to the

promotion of uniform radiation measurements:

"1. Assure the existence of basic standards of the necessary accuracy.

2. Assure the existence of transfer standards of the necessary

accuracy.

3. Develop adequate and reliable field instruments.

4. Develop adequate means for calibrating field instruments.

5. Assure that at all times any instrument reading anywhere can be

traced to its basic calibration source.

6. In measurements anywhere, do not lose your sense of humor."

NOTE: Not all references listed at the end of this report are specifically

referred to in the text or tables. It would be necessary to increase

substantially the size of the tables to include the references for

each chemical procedure avaiU )le, for example. The intent was to

list references, however, for explicit purposes and procedures which

should be available to all state personnel.

B-5
DEFINITIONS OF TERMS

THE MEANING OF ACCURACY

There are several terms which must be understood in order to discuss the

problems encountered in radiation measurements. This understanding is

especially important in the context of this report because many people

use the terms interchangeably to describe concepts which are fundamentally

different. The terms are "accuracy," "bias," "reproducibility," and

"precision." Webster defines them as follows:

Accuracy "Degree of conformity of a measure to a standard

or true value."

Bias "Systematic error introduced into sampling or testing by encouraging one outcome or answer

above others,"

Reproducibi lity "The ability to 'cause' (the value of a measurement) to exist again."

Precision "The degree of reproducibility with which an operation is performed or a measurement stated."

In the National Bureau of Standards Handbook 80 [7]* entitled "A Manual of

Radioactivity Procedures," these terms and their relationship to one another are further explained.

Reproducibility and precision are very closely related and are usually

expressed as the amount of variation to be expected between two or more measurements of the same quantity. Precision can be determined or (more

properly) estimated from the results of a series of measurements. The

standard deviation of the set of resultant values is usually taken as a measure of the precision.

"Accuracy" and "bias" are many times used interchangeably, but in the

context of this report must be considered to be very different. Bias can be determined quantitatively as the amount by which a measurement

(if only one is available) or the average of a series of precise measurements differs from the "true" value. Bias is many times called 'systematic error' and can be expressed quantitatively as the amount by which the

average of a series of precise measurements differs from the true value.

Accuracy is difficult to determine quantitatively since its essential

components (bias and precision) cannot be combi ned in any simple fashion

to produce a single measure which is meaningful. Instead, the accuracy

required of a measurement system must be judged in terms of a predetermined degree of uncertainty which is acceptable for the type of

measurement under consideration. The accuracy of the measurement can then

be judged acceptable if the uncertainty associated with the result(s)

lies within the acceptable range. Only in this case would the difference

between the measured and true value not exceed the degree of acceptable

uncertai nty

.

*NBS Handbook 80 has been superseded by NCRP Report 58 [1]

B-6
An essential part of this problem is that the result of a measurement is

affected by all aspects of the measurement system, which includes not

only the instrumentation used to make the measurement but the procedures

used in operating the instruments, the care which the person making the

measurement takes to follow the procedure, and the selection of the

sample on which the measurement is to be made or the location at which

the measurement is to be made. These aspects, and there are others, are sources of error which can affect both the bias and precision of the

measurement.

Cali and Reed [22] have defined an accurate measurement system as "one

that produces precise numerical values of the property or properties

under test or analysis that are free of, or corrected for, all known

systematic errors. Such values are also related to the 'true value' of

the property(ies) under test or analysis."

In the following figures, the inner circle is the acceptable range of error of a measurement with the 'true value' being at the center. If

the results of a series of measurements lie within this circle, then the

accuracy of the measurement sytem is considered to be acceptable.

In Figures 1 and 2, the measurements have the same precision but are displaced (biased) from the center by different amounts. In Figures 1 and 3 the averages of the measurements have the same bias, but with

different precision. In Figures 3 and 4, the measurements have the same precision, but the biases are different.

Figure 4 is the only one in which the accuracy is acceptable because

both the bias and precision are such that the results of the measurements are within the acceptable range of uncertainty. In Figure 1 the

accuracy is not acceptable because of both large bias and poor precision.

In Figure 2 the accuracy is not acceptable because, while the bias may

be acceptably low, the precision is so poor that it is not possible to

make a decision as to the amount of bias which may be present and very

few of the measurements fall within the acceptable range of uncertainty.

Figure 3 has unacceptable accuracy because of the large bias, even

though the precision is acceptable.

B-7
Fig. 1. Inaccurate, large bias, Fig. 2. Inaccurate, questionable

and poor precision. bias, and poor precision.

Fig. 3. Inaccurate, large bias. Fig. 4. Accurate, acceptable bias,

and acceptable precision. and acceptable precision.

B-8
GENERAL DISCUSSION OF TABLES I-IV

In the following tables the column headed "Application" contains the

type of radiation measurement which is to be made. The second column,

labeled "Regulatory Criteria," lists those issuances which contain limits or criteria to which radiation measurements may be compared and, in some

cases, the numerical value of those limits or criteria.

The column labeled "Range Expected" is the range of radiation characteristics

which is expected to include most of the measurements made for a particular

purpose. Values included here are based on a consensus of the Task Force

members and others.

The column headed "Accuracy Requirements" contains values which express the consensus of measurement accuracy required to enable good decisions as to

whether or not regulatory action should be taken. By way of explanation, it

is considered that those measurement results which are near the regulatory limit

require the best accuracy because it is at this point where a decision may be

difficult. The following two examples illustrate that for measurement far from

the regulatory limit even large errors will not affect decisions determining the

need for regulatory action. First consider the case where the measured value

is 5% of the limit. Even if there is a 100/^ error on the measurement, such

that the true value is between 07o and 10% of the limit, there is no need for

regulatory action. Second, consider the case where the magnitude of the error

equals the limit. If the measured value is 300% of the limit, such that the

true value is between 200% and 400% of the limit, there is a need for regulatory

action. If the measurement and its error had included the regulatory limit,

then there would have been some question as to the propriety of either decision

and whichever decision was made would have been subject to valid criticism.

The fact that an error of 100% may be acceptable under certain circumstances

does not mean that errors of this magnitude should be tolerated. The consensus is that measurement errors as great as 50% may be tolerable when

the measurement is made for screening purposes. These would be subject to

verification if the screening measurement were close to the regulatory limit.

The measurements for verification purposes should not be subject to errors greater than 10% to 20%.

The last column of the tables, headed "Instrument Considerations," lists some of the types of instruments suitable for particular types of applications and some of the essential characteristics of the instrumentation.

One of the essential characteristics not mentioned in the tables is that

the instrument absolutely must be capable of detecting the type of radiation

to be measured. This may seem to be obvious, but there are many documented

instances in which the presence of alpha-emitting radioactive material has

been sought with a Geiger-Muel ler (G-M) detector with stainless steel walls.

Other instances have been documented in which attempts were made to measure

low energy x rays with uncalibrated G-M survey meters. It is essential that

those people who are required to make radiation measurements be provided with

instrumentation which is appropriate for the type of radiation to be measured

B-9
and which has been properly calibrated with that type of radiation. They

should also have been trained in the proper procedures for making

measurements and in the choice of proper instrumentation. Interpretation

of the results of those measurements (including the interpretation of the

associated errors) is an essential part of the training.

In that light, the measurement of neutrons probably represents the greatest

dilemma for the inspector. Sources which emit neutrons present a problem

in measurement which is difficult but not insurmountable if the appropriate

measuring equipment is available. Other sources are on the market which emit

neutrons although not designed specifically for that purpose (industrial and

medical accelerators). Due to the magnitude of the problem and the still

unsolved methods of routine neutron measurement around those devices, they

will not be included until some of these problems can be resolved.

J',

Note added in proof: A glossary of abbreviations of terms and units used

in the tables is included as Appendix III to this report.

B-10
HEALING ARTS X-RAY SURVEY MEASUREMENT CRITERIA

(Table I)

Measurements in the healing arts x-ray field are becoming more and more

complex with the emergence of highly technical and specialized medical

x-ray equipment. Promulgation of the Federal x-ray performance

standard has added to the complexity of such measurements. This table

outlines the different types of measurements which must be made on healing arts x-ray equipment as well as regulatory limits or criteria

which must be used in the decision-making process. It is vital that

instruments used to measure x rays be calibrated with x rays in the

appropriate energy range.

Problems of instrument energy dependence can be partially solved by

calibrating at a number of different energies and then plotting the

response of the detector vs. energy. However, to use this information

accurately, the energy spectrum of the equipment under test must be

known. Since spectral measurements are not routinely performed in the

field extreme care must be exercised in applying energy-dependent

correcti ons

.

Certain common attributes of instruments used for measurement of healing

arts X rays have been omitted from the table. The instrument is assumed

to be a rugged, portable survey meter with minimal temperature dependence,

exposure rate dependence, directional dependence, background, and effects

from other environmental causes, in addition to the other specific

characteristics in the table. As a minimum, the instrument must be able

to maintain a level of performance consistent with the accuracy requirement.

B-11
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B-13
NON-MEDICAL X-RAY SURVEY MEASUREMENT CRITERIA

(Table II)

This table includes a wide range of non-medical applications of x rays.

The range of radiation energies and intensities is very wide, and instruments must be used which respond adequately for the particular application

being considered.

As in medical x-ray measurements, it is important that instruments be

calibrated over the appropriate range of energies typically encountered.

This is necessary because most survey instruments show appreciable energy

dependence over this broad range.

Since a wide range of environmental conditions will also be encountered,

other effects on instruments must be considered. Shielding against the

effects of radio-frequency radiation is important in airports, for example,

when surveying baggage inspection units. The presence of radio-frequency

and radar fields can result in erroneous indications from unshielded

survey instruments. [17]

In using ion chamber type instruments, it is important that the entire

active volume of the chamber be exposed to the x-ray field. If the entire

chamber is not exposed, the meter indication will be low. Corrections

can be applied if the beam size is known.

Instruments which are intended for use in high-energy radiation measurements

should be calibrated with a suitable high-energy source of radiation.

Build-up caps may have to be used to achieve adequate accuracy at higher

energies. If measurements are made with the use of a build-up cap, it must

also be in place during calibration.

Neutron contamination may be present when measuring radiation fields with

energies above approximately 10 MeV. Instruments used primarily to measure

photon radiation will not respond properly to neutron radiation, and the

total radiation hazard will be underestimated as a result. Thus an instrument capable of measuring neutron radiation should be available.

High voltage generators, capacitor banks, transformers, and other electromagnetic equipment may generate x radiation during normal modes of operation

or malfunctions. For instance, high-voltage transformers above 10 kV may

produce x rays inadvertently, particularly if the transformer undergoes

electrical breakdown. Capacitor banks can be a source of x radiation during

breakdown of the dielectric at voltages above 10 kV. Capacitor discharges

can produce x rays by a mechanism similar to that incorporated in capacitive

discharge x-ray machines. Survey equipment used for these measurements must

also be shielded against electromagnetic radiation in the radio-frequency

range as well as being energy and rate independent.

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B-16
X-ray Measurement Problems Encountered

It should be noted that even though calibration techniques may be available,

they may not fill all needs for a specific measurement. An example of this

is the measurement of scatter from a medical x-ray unit. The specified

range of the instrument is from a few mR per hour to several R per hour. It may only be practical to calibrate the instrument with an exposure of approximately

1 R per hour. However, the requirement may necessitate measuring 2 mR per hour.

On multiscale instruments, some other way must be used to determine if a measurement on a lower range (maybe 3 mR per hour full scale) is also accurate.

It might be possible to do this check electrically but, by any method, something must be done to insure accuracy on the scale actually used for the

measurement.

This problem is only the tip of the iceberg of measurement problems encountered.

The accuracy requirements include the overall accuracy of the instrument,

including effects due to energy dependence of detector, directional dependence

of detector, exposure-rate dependence of detector, background noise or leakage

of detector and readout, dynamic range of readout, scale non-linearities of

readout, inability of readout to track linearly from scale to scale, and other

serious environmental effects on both detector and readout. Problems of detector

energy dependence can be partially solved by calibrating at a number of different

energies and then plotting the response of the detector vs. energy. However,

to use this information accurately, the energy spectrum of the equipment under

test must also be known, and this is usually not the case. Many of the parameters

mentioned above are provided by the manufacturer of the instrument. Unfortunately,

not all manufacturers provide all the information, and those who do provide

information are not uniform in how they specify the tests. Even more unfortunate,

the limitations of the instruments are often overlooked when the measurement is

performed.

The topic of environmental effects must be considered. Since most instruments

used for x-ray measurements are vented air ionization chambers, it is obvious

that corrections should be made for temperature and pressure variations in the

environment. Not so obvious is the problem of the time lag involved before the

air in the chamber achieves equilibrium with the ambient conditions after a change from one location to another, for example from a car trunk in summer to an air conditioned building. For some chambers, this lag could approach hours.

Also, the change in relative humidity inside the chamber could cause increased

leakage.

It must be noted that low levels of radio-frequency interference (levels which

have been measured in hospital environments) can cause serious errors in most

ionization chamber type instruments . [1 7] There is reason to believe that

other environmental factors may cause equally serious effects.

The discussion above is not all-inclusive. The instruments in use are not

ideal and, therefore, must be calibrated and corrected. Some of the required

measurements outlined in the tables are very difficult, if not impossible, to

make with present technology. However, with careful analysis and understanding

of the measurement problem, many technically valid tests may be performed.

B-17
In some respects, equipment available for surveys around medical and

dental x-ray machines comes closer to satisfying the needs of state

programs than most of the instrumentation designed for use in other

areas. Yet, routine x-ray safety evaluations by state inspectors are - subject to errors from sources other than the measuring devices.

Perhaps the major source of inaccuracy in the measurement system is

the human element. The inspector's ignorance of, or inattention to,

particulars of the measurement environment or limitations in the

equipment may lead to incorrect or meaningless results. These factors

can only be minimized by proper training and strict adherence to welldesigned survey procedures.

Inspectors' techniques are often a significant factor resulting in a compilation of meaningless data. Since an inspector's performance

may be evaluated on the basis of the number of machines checked, some individuals cut corners on the established survey procedures to increase

productivity. This, coupled with their own vagueness concerning their

equipment, has produced in at least some cases a scenario very similar

to the following:

Arriving at a doctor's office, the inspector takes his survey equipment

out of the trunk of his car where the temperature exceeds 120°F and

enters the air-conditioned office. Moisture condenses inside the ionization

chambers, and no time can be permitted for proper humidity and temperature

equilibration. The doctor is also in a hurry and makes it clear that the

inspection is costing him money, so no time is spent setting up the NEXT

test stand; all output measurements are made with the chamber mounted in an inappropriate position. Half-value layer measurements are made with the

aluminum filtration resting on top of the chamber, and the collimator of

the unit is set at any convenient aperture. Scatter measurements are made

at the same time and the exposure interval is less than a second. No

correction for instrument response time is made. The instrument may be

placed outside of the protective barrier with no consideration given to

directional dependence. The survey is completed as quickly as possible.

The film badge records are leafed through, and the inspector departs for

the next facility after a brief interview with the doctor. Total time

elapsed is a fraction of the time necessary for adequate inspection of a one-machine facility. The details on the inspection form may be filled

in later.

The inspector in this case probably has no idea what effect these modified

procedures have on his measurements, and his supervisor is not aware that

the results of the inspection have been compromised because field performance

evaluations are not routine.

B-18
RADIOACTIVE MATERIAL MEASUREMENT CRITERIA (RESTRICTED AREAS)

(Table III)

The measurement of radiation from radioactive material covers a wide

variety of applications or purposes. As a result, there are numerous regulatory limits or criteria which apply to different situations, as well as a broad range of radiation levels which must be measured. It

is essential that the person making the measurement be familiar with

the instrument requirements for the particular measurement, e.g., type

of radiation, energy of radiation, intensity, and rate dependency. Other

considerations are noted in the table for each particular application.

Instruments used for these measurements should be operable over a wide

range of environmental conditions such as temperature and humidity,

relatively easy to operate and maintain, and capable of measuring the

quantity of radiation or radioactivity encountered. Instruments used

in field surveys should be portable, rugged, and appropriate for the

intended purpose. Ancillary equipment needed to support the measurement,

such as air sampling equipment, power supplies, etc., should also have

many of the above attributes.

One must know the purpose for making the measurement, which then dictates

the accuracy required. Calibration is essential to the measurement system,

since a radiation measurement is no better than the calibration of the

instrument used in inaking the measurement.

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B-20
RADIOACTIVE MATERIAL MEASUREMENT CRITERIA (UNRESTRICTED AREAS)

(Table IV)

Table IV consists of common measurements that are made by state and

Federal agencies for radioactivity in environmental samples. The

regulatory criteria given for each application consist of Federal

guidance or regulation and/or state regulation. Expected ranges

are based on data from measurements currently made in the environment. Accuracy requirements are based on current desirable procedures and measuring equipment available, as well as projected needs.

Instruments are listed by type for the various measurements. The

list of instruments is not intended to be all-inclusive but is an example of the minimum equipment necessary to measure environmental

radioacti vi ty.

Radiation measurements in unrestricted areas include measurements

of external radiation which impinges upon the body from outside

sources and radioactivity in airborne particulates, gases, and

liquids. These kinds of measurements are associated with environmental radioactivity monitoring programs carried on by states in the

vicinity of potential sources of environmental radioactivity, including nuclear power plants and large hospital complexes. These

measurements are also performed in other areas where environmental

radioactivity is of concern. Milk, air, and water are commonly

monitored by many state programs. In addition, the federal drinking

water standards require screening of water supplies for gross alpha,

gross beta, and identification and measurement of certain specific

radionuclides in samples which exceed the screening levels.

Measurements for contamination, leak tests, lost sources, and emergency

response require varied instrumentation. The table lists a few common

instruments, required accuracy, and expected ranges. No attempt, however,

was made by the Task Force to exhaustively study each application due

to the multitude of measurements that might be required.

A list of radionuclides used for calibration by states is shown in

Appendix I. If a sealed liquid source is received by a laboratory from

NBS and is opened for analysis, it is no longer considered the "same,

identical sample" prepared by NBS. As a consequence the result of the

analysis of that sample is not traceable to NBS but may have some

degree of credibility. If the results of the "round robin" or "blind"

analysis of samples fall within the limits established by the sponsor

of the samples, traceability may be achieved if the sponsor is NBS or

a laboratory that has achieved traceability like EPA, Las Vegas.

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B-23
APPENDIX I

LIST OF RADIONUCLIDES USED FOR CALIBRATION OF COUNTING SYSTEMS

[FROM ALL-STATES QUESTIONNAIRE - 1976-1977]

(For availability see Ref. 21)

(Also see Footnote - Appendix II)

H-3 Ru-106 Pu-239

C-14 Cd-109 Am- 241

Na-22 Ag-110 Pu-241

Cl-36 Sb-124 Pu-242

K-40 Sb-125 Mixed Gamma

K-42 1-131

Sc-46 Ba-133

Ca-45 Xe-133

Cr-51 Cs-134

Mn-54 Cs-137

Co-56 Ba-La-140

Co-57 Ce-141

Co-58 Ce-Pr-144

Fe-59 Eu-152

Co-60 Eu-154

Zn-65 Hf-181

Se-75 Hg-203

Kr-85 Tl-204

Sr-85 Bi-207

Y-88 Pb-210

Sr-89 Po-214

Sr-90 Ra-226

Y-90 Ra D+E

Zr-Nb-95 Th-natural

Tc-99m U-natural

Ru-103 Pu-236

B-24
APPENDIX II

SOME NECESSARY REFERENCE STANDARDS IN THE MEDIA ENCOUNTERED

MEDIUM MATRIX TYPE ISOTOPES

Water

Water

Milk

Milk

Air

Air

Sediments

Plant and animal

tissue

True Solution

Mixture of suspendeddissolved

Typical organic

.bound/non-bound

mixture

Particulate

Iodine

Dried and/or

ashed tissue

Mixed Y emitters

Sr-89-90

Ra-226-228

Mixed Y emitters

Sr-89-90

Ra-226-228

1-129-131

Mixed Y emitters

Sr-89-90

Ra-226-228.

Mixture of a,B,Y emitters

on filter impregnated with

normal dust loading.

Charcoal absorbers impregnated

with various materials

(KI, TEDA, etc.) suitable for

both direct y analysis as well as chemical separation.

Mixtures of both natural and

man-made Y)3>ct emitters most

likely to be found in sediments

Mixture of those most likely to

be concentrated by the organism.

Three levels of concentration of radioactivity are needed:

1. - 10 x normal background for equipment calibration purposes.

2. Approaching the lower limit of detection (LLD) for a check of analytical

methodology. (LLD as defined by the USNRC)

3. 100-10*00 times normal background to test accuracy.

FOOTNOTE : Many of the radionuclides are available from the common sources but may

not be considered "Standards". Traceability to NBS must be established

with these sources before they can be considered acceotable for calibration

(See Ref. 21)

B-25
APPENDIX III

GLOSSARY

alvmimm - (ASTM Type 1100)

BEM - Breast Exposure: Nationwide Trends

hkg - background

BRU - Bureau of Radiological Health

CABINET - Enclosed x-ray machine for radiography ,

CFR - Code of Federal Regulations

Ci - Curie

DCPA - Defense Civil Preparedness Agency

DENT - Dental Exposure Normalization Technique

DOT - U.S. Department of Transportation

dpm - Disintegrations per minute

EVA - Environmental Protection Agency

EAA - Federal Aviation Administration

Film Badge - Personnel dosimeter containing film

EYL - Half Value Layer

ICRP - International Commission on Radiological Protection

kv - Kilovolt

fe7p - Kilovolts peak

MeV - Million electron volts - energy

MPBB - Maximum permissible body burden

MFC - Maximum permissible concentration

mJR - 1/1000 of a roentgen (mi 1 1 i roentgen)

mrem - 1/1000 of a rem (millirem)

NEXT - Nationwide Evaluation of X-ray Trends

NEC - Nuclear Regulatory Commission

NRC (10 CFR 20) - Nuclear Regulatory Commission (Title 10, Code of

Federal Regulations, Part 20)

B-26
pCill - Picocurie per liter (lO"^^ Curie /I)

Q!IR - Quarter

R - roentgen

rem - roentgen equivalent man

RF - Radio frequency

RSO (or RPO) - Radiation Safety Officer

S.S.R. (or State Regs) - Suggested state regulations for the control

of radiation

TLD - Thermoluminescent dosimeter

a - alpha particle ,

3 - beta particle

Y - gamma ray

= milli (1 x 10"^

y = micro (1 x 10"^)

p = pi CO (1 X 10-12)

B-27
REFERENCES

1. National Council on Radiation Protection and Measurements, Report #58,

A Handbook of Radioactivity Measurements Procedures, November 1978.

2. Federal Register, Vol. 41, #133, 7/9/76, Federal Drinking Water Regulations,

U.S. Environmental Protection Agency.

3. Kanipe, L.G., Handbook for Analytical Quality Control in Radioanalyti cal

Laboratories. EPA 600/7-77-088, Aug. 1977.

4. Easterly et al.. The Status and Quality of Radiation Measurements for Air,

EPA 600/4-77-043, Oct. 1977.

5. Easterly et al.. The Status and Quality of Radiation Measurements for Food

and Human Urine, EPA 600/4-77-047, Oct. 1977.

6. HASL Procedures Manual, U.S. Energy Research and Development Administration

Report, HASL-300, 1972.

7. "A Manual of Radioactivity Procedures," National Bureau of Standards

Handbook 80, 1961

.

8. Snedecor and Cochran, Statistical Met;hods, Iowa State University Press,

Ames, Iowa, 6th Ed. 1968.

9. Standard Methods for Examination of Water and Waste Water (Latest Edition)

American Public Health Association, American Water Works Association and

Water Pollution Control Federation.

10. Quality Assurance for Radiological Monitoring Programs (Normal Operations)

Effluent Streams and the Environment, USNRC Regulatory Guide 4.15, Revision

1 , February 1979.

11. Kathren, R.L., Standard Sources for Health Physics Instrument Calibration.

Health Physics Vol. 29: pp 143-153, July 1975.

12. Branch Position for Preoperational Radiological Environmental Monitoring

Programs for Uranium Mills, USNRC Fuel Processing and Fabrication Branch,

17 pages, Jan. 9, 1978.

13. National Uses and Needs for Standard Radioactive Materials. A Report by an Ad Hoc Panel of the Committee on Nuclear Science, National Research Council.

National Academy of Sciences, Washington, D.C. 1970.

14. EPA 670/4-75-006 (June 1975), Activities and Needs Related to Radioactivity

Standards for Environmental Measurements. Symposium in Washington, D.C.

Aug. 21, 1973, Ed. Eldridge and Kahn.

15. Design and Operation of Secondary Standard Laboratories for Radiation

Dosimetry, Victoreen Instrument Division, Dec. 1977.

B-28
16. Ziegler, L.H. and H.M. Hunt, Quality Control for Environmental Measurements

Using Gamma-Ray Spectrometry, EPA 600/7-77-144, 147 pages, Dec. 1977.

17. Frazier, J.R., T.R. Ohlhaber and P.S. Ruggera. "Performance of X-ray

Measurement Instruments when Subjected to Environmental Level R.F. Fields,"

HEW Publication (FDA) 78-8065, June 1978.

18. "Certificates of Radioactivity Standards" Recommended by the Subcommittee

on the Use of Radioactivity Standards of the Committee on Nuclear Science,

Division of Physical Sciences, National Academy of Sciences-National

Research Council, Dec. 1966.

19. "Users' Guide for Radioactivity Standards" Recommended by the Subcommittee

on the Use of Radioactivity Standards, Committee on Nuclear Science, Division

of Physical Sciences, National Academy of Sciences - National Research

Council, Oct. 1967.

(N.B. This particular document gives a great deal of information on the

pitfalls of counting certain radioactive substances.)

20. Healy, J.W. Los Alamos Handbook of Radiation Monitoring, 1970, LA 4400

(Formerly LA-1835).

21. International Directory of Certified Radioactive Materials, International

Atomic Energy Agency Report STI/PUB/398, 1975.

22. Cali, J. P. and W.P. Reed. "The Role of the National Bureau of Standards

Standard Reference Materials in Accurate Trace Analysis" National Bureau

of Standards Special Publication 422, pp 41-54, Aug. 1976. Proceedings

of the 7th IMR Symposium.

23. Lubenau, J.O. and R. Librace. "Performance Characteristics of Selected

Integrating Ion Chambers." Jour. Health Physics Soc. 33:199-203, 1977.

B-29
NBS-114A IREV. 9-761

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO.

NBS GCR 79-174

a. Gov't Accession NoJ 3. 'k«eipfe«t' s Accession NoT

4. TITLE AND SUBTITLE

Ionizing Radiation Measurement Criteria for

Regulator Purposes

5. Publication Date November 1979

S. PeHttrming Organization Cod«

7. AUTHOR(S)

None

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND COMPLETE ADDRESS rS(ree(, City, St^te. ZIP) Conference of Radiation Control Program Directors, Inc.

E. Frank Wilson, Sec./Treas.

4815 West Markham Street

Little Rock, Arkansas 72201

Ift. Project/Task/Work Unit No.

11. Contract/Grant No. 7-35787

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS fSfree(. City, state. ZIP) National Bureau of Standards

Department of Commerce

Washington, DC 20234

13. Type of Report & Period Covered

Final

14. sponsoring Agency Code

15. SUPPLEMENTARY NOTES

[_J Document describes a computer program; SF-185, FIPS Software Summary, is attached.

To

16, ABSTRACT (A 200~word or less factual summary of most signi ficant information. If document ir^cludes a significant bibliography or

literature survey, mention it here.) A number of approaches could have been made for providing the reader with the

information contained in this publication. In the interest of brevity, it was deemed

necessary to develop definitions and tabularize the material that could be most

easily utilized by those persons enforcing certain regulatory requirements and

guides as well as those persons who are affected by the requirements and guides

that end, this report:

Defines "accuracy" which is necessary for radiation control

Lists pertinent regulatory criteria and limits

Lists the radiation sources that require measurements

Lists the expected ranges for those measurements

Lists the accuracy requirements

Lists the instrument considerations necessary to make those

accurately

Discusses some of the problems and pitfalls in radiation control

purposes

measurements

measurements

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Accuracy; criteria; instruments; measurements; radioactivity; regulations; x-ray.

18. AVAILABILITY Unlimited

rxl For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc, U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003-

Order From National Technical Information Service (NTIS), Springfield,

^ VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

(THIS PAGE)

UNCLASSIFIED

21. NO. OF

PRINTED PAGES

30

22. Price

B-30

USCOMM- DC
APPENDIX C

G rowth and Economic Value of Applications Involving the Use of Ionizing Radiation:

Five Examples

Five representative examples are briefly highlighted to illustrate the economic

value and rapid growth of applications involving the use of ionizing radiation.

1 . Selected Atomic Energy Products

Data on the monetary value of shipments of selected atomic energy

products (excluding radiation detection and monitoring devices, and control and

measuring devices containing radioactive sources) which are manufactured in

privately owned establishments are available from the Bureau of the Census

[Census, 1978]. The value of shipments of these products from 1968 through 1973

is shown in Figure 1. As indicated, there has been a 235 percent Increase

during the past decade, and the current worth is approximately $1.7 billion.

2. X-ray Equipment and Accessories

The total value of shipments of all x-ray and medical electronic

apparatus In 1975 and 1976 [Shope, 1978] was $829 and $943 million, respectively

(Table I). X-ray equipment and accessories constituted approximately half of

these totals, and Its value for these two years was $412 and $492 million. Dental

units typically cost $4000 to $10,000; and medical units: $20,000 to $150,000.

There are approximately 125,000 medical and 145,000 dental x-ray units in the

country [Moats, 1978]. Since the average lifetime of these units is 20 years,

approximately 13,500 x-ray units must be replaced each year.

C-1
c-2
Table I

Value of Shipments of X-Ray and fledical Electronic Apparatus

Value of Shipments ($1000)

1976 1975

Medical diagnostic and therapeutic

electronic equipment, except x-ray:

450,693 417,568

X-ray Equipment and accessories:

Medical and dental x-ray and gamma

ray equipment

338,717

Industrial and scientific x ray 38,475

X-ray equipment accessories 58,397

X-ray tubes and valves, sold separately 56,226

Total: 942,508

X-ray equipment as a percentage of total 52.2%

286,700

32,357

42,868

49,771

829,264

49.6%

C-3
3. Computed Tomography X-Ra.y Systems (CT Scanners)

An area of diagnostic medicine which has undergone rapid development

due to the introduction of a new technology has been that of computed-tomography

x-ray systems (i.e., CT scanners). The pioneering work was done by Hounsfield in

England, and the first clinical unit was installed at Wimbledon in 1971. The

vast increase in diagnostic information available using CT scanners, particularly

for head scans, was quickly recognized, and the first commercial scanners in

this country were installed during 1973. Table II shows the growth in the number

of CT scanners from 1975 to 1978. These values are based on preliminary data

from the Bureau of Radiological Health [Shope, 1979] and were determined from

assembler reports. They could be in error by 10 to 15% due to incomplete reporting.

Table II

Number of CT Scanners

Year Head Scanners Body Scanners

1975 140 40

1976 225 225

1977 310 655

1978 405 825

4. Radioactive Diagnostic Products

Another medical area experiencing rapid growth is radiopharmaceuticals

used for diagnostic nuclear medicine procedures. Figure 2 shows the annual

C-4
c-5
growth rate of sales of radiopharmaceuticals (in millions of dollars) used for

in vivo and in vitro diagnostic procedures during 1972-1976, and the estimated

growth rate for years later than 1976 [SRI, 1978]. It has been estimated

[Mclntyre, 1979] that the number of nuclear medicine procedures, in distinction

to the value of sales, has been increasing at 20% per year from 1975 to 1979.

Hence, the number of procedures has risen from 7 million in 1975 to an estimated

14.5 million in 1979. .

5. Industrial Radiation Processing

Industrial radiation processing is usually performed with radiation

60 from either intense cobalt ( Co) sources or electron beam accelerators. Figure

3 shows the growth of the total installed capacity in megawatts, for both cobalt and electron beam irradiation facilities [Anon., 1977]. Historically, the

primary applications have been in curing plastics and in sterilizing medical

products. These two applications use roughly 80% of the total installed irradiation capacity, and in 1977 produced products worth an estimated value of $1

billion dollars. Since then, sterilization of medical products by irradiation

has probably increased because of the ban placed on the use of ethylene oxide

(a mutagenic gas formerly used as an antiseptic agent). There have been many

new applications of radiation processing including hardening metal, disinfecting

sewage, byproduct recovery, food preservation, water treatment, pollutant removal in industrial gas stacks, and sludge processing.

C-6

References

Bureau of the Census, "Selected Atomic Energy Products, 1977" Current

Industrial Reports MA-38Q(77)-1 (September, 1978).

Shope, T.B. and Rudolph, H., A Second Look at the Costs and Benefits with

the Diagnostic X-ray Equipment Performance Standard and the Policy on Assembly

and Reassembly. Draft No, 3. Food and Drug Administration, Bureau of Radiologica

Health (Nov. 1978).

Moats, R.A. and Miller, L.A., Report of State and Local Radiological Health

Programs: Fiscal Year 1977, Bureau of Radiological Health, HEW Publication

{FDA)-78-8034 (1978)

Shope, T.B., Bureau of Radiological Health, private communication (1979).

Stanford Research Institute, SRI International Health Industries Handbook

(1978).

Mclntyre, A.B., Bureau of Radiological Health, private communication (1979).

Anonymous, "Radiation's Bright New Futures, Business Week, July 11, 1977.

C-8
Appendix D

Surrmary of Recent Estimates of Occupational Exposure

to Ionizing Radiation

In a current study to reevaluate occupational exposure limits for ionizing

radiation, the Environmental Protection Agency [Garcia, 1979; Cook, 1979] divided

the work force into five broad categories: —medicine

--industry

--government

--education

--nuclear fuel cycle.

All workers within a given category are not necessarily exposed to radiation. For

example, not all physicians in the medical category may be exposed. Further,

many workers who may be exposed receive less than a measurable amount of radiation

on their personnel monitors. Therefore, within each category, the workers were

considered in two ways:

°all workers who may be exposed (or "potentially exposed") to radiation

°only those workers who actually receive a measureable amount of radiation

The EPA estimates that there are 1.2 million workers who may be occupational ly

exposed. Of these, about 400,000 workers receive measurable amounts of radiation.

Figure 1 shows the distribution of these workers in each of the five major

categories. It can be seen that the category with the largest number of workers

is the medical profession. This category constitutes 45% of the work force which

may be exposed, and 38% of the work force which is measurably exposed. The

nuclear fuel cycle workers comprise 6% of the work force which may be exposed,

but 19% of the workers actually receiving measurable amounts of radiation.

D-1
600

ALL WORKERS WHO

MAY BE EXPOSED

500

400

300

200

100

0

ONLY THOSE WORKERS

RECEIVING MEASURABLE

AMOUNT

MEDICINE INDUSTRY GOVERNMENT EDUCATION NUCLEAR

FUEL CYCLE

Fig. 1. Categories of workers who may be exposed to radiation.

D-2
The EPA estimate [Cook, 1979] of the approximate dose received by workers

in the five categories is shown in Figure 2. As before, the average dose to

workers is estimated for all workers within a category who may be exposed, and

for those workers who receive a measurable dose. Of the five broad categories,

the workers in the nuclear fuel cycle receive the highest average dose:

0.34 rem for all workers who may be exposed; 0.63 rem for those workers

receiving measurable amounts.

Although the results are not provided here, the average dose received by

workers in specific occupations within each of the five categories show considerable variation [Cook, 1979]. The occupational group which has the largest average

dose is industrial radiographers who receive measurable amounts of radiation:

0.85 rem.

Considering the entire 1.2 million workers who may be occupational ly exposed

to ionizing radiation

°65% receive less than measurable doses

°95% receive less than 0.5 rem per year

°99.8% receive less than 5 rem per year

The average annual per capita dose to all occupational ly exposed workers is 0.11 rem

The average annual per capita dose to those receiving measurable amounts of

radiation was 0.31 rem. This is in addition to the 0.2 rem annual per capita

dose due to natural background and man-made sources of radiation.

The Nuclear Regulatory Commission (NRC), in a detailed study of occupational

radiation exposure at NRC-licensed facilities for 1975 [Cool, 1978], made

estimates of the dose received by workers in various licensee categories involving

NRC-licensee material (Byproduct, Source, and Special Nuclear Material). An

abbreviated summary of the results of this study is provided in Table I. The

table lists those occupational categories at NRC-licensed facilities in which

D-3
AVERAGE DOSE TO

THOSE WORKERS RECEIVING

MEASURABLE DOSE

MEDICINE INDUSTRY GOVERNMENT EDUCATION NUCLEAR

FUEL CYCLE

Fig. 2. Estimated approximate dose received by workers

occupational ly exposed to ionizing radiation.

D-4
Table 1

NRC License Material with Average Measurable Dose Greater Than 0.25 rem or Individuals Receiving Greater Than 1 rem in 1975^^^

Number of*

- —

r

Average Greater Precent Greater Than

Category of i Licenseendi vidua 1

s

monitored

measurabl

e

dose

Less than

measurabl

e

0-1 1-5

Than

5 1 rem 5 rem

Byproduct

Material

Waste Disposal

Burial

65 1

.

26 1 38 26 0 40 0 0 0

Well Logging 1514 0. 50 186 1161 163 4 1

1

0 0 3 Irradiator

{>10'* Ci)

134 0. 38 133 1 0 0 0 0 0 0

Private

Practice

486 0. 35 94 362 26 2 5 8 0 4

Tel etherapy 1716 0.29 789 872 55 0 3 2 0 0

1 lib I. 1 L . U Lilci Med.0. 28 w)00 1 q 3 1 0 09

Marketing Other 1195 0.28 902 274 19 0 11 D n n Other Medical 356 0. 27 188 159 8 1 C

c; n n Marketing Board 703 0. 26 563 129 11 0 1 6 0 0 Other Measuremen

Systems

t 2594 0.14 1541 1048 5 0 0 2 0 0

Source Material

U Mills 437 0. 41 33 363 41 0 9 4 0 0

UFe Processing 522 0. 22 192 328 2 0 0 4 0 0 Other U (>150 kg)

149 0. 17 41 104 4 0 2 7 0 0

Special Nuclear Material

Unencapsulated

SNM

204 1

.

54 190 6 8 0 3 9 0 0

Power Reactors 54763 0 76 26729 20797 6971 266 13 2 0 5 Fuel Storage 13 0 69 0 12 1 0 7 7 0 0 Manufacture &

Di stri bution

3367 0 64 1508 1545 287 27 9 3 0 08

Radiographers 9178 0 60 4485 3847 808 38 9 2 0 4 Fuel Proc. and

Reproc.

11614 0 57 6012 4856 667 79 6 .4 0 .7

Other SNM 203 ° 13 126 76 1 0 0 5 0 0

* Actual number of individuals monitored by reporting fraction. Total number monitored

by individuals will be higher.

(1) From NUREG-0419, Occupational Radiation Exposure at NRC-Licensed Facilities: 1975

D-5
the average dose for the category exceeded 0.25 rem per year and those categories

in which individual workers were exposed to more than 1 rem per year. For each

category, the table provides the number of individuals monitored, the average

measurable dose in rem, and the distribution of the dose in four broad ranges.

For the monitored workers in all occupational categories of Byproduct Material

licensees (18,400 workers)

°43% received less than measurable doses

°97% received less than 1 rem per year

°99.9% received less than 5 rem per year.

For the monitored workers in all occupational categories of Source Material

licensees (1 1 00 workers)

°24% received less than measurable doses

°96% received less than 1 rem per year

°all received less than 5 rem per year.

For the monitored workers in all occupational categories of Special Nuclear

Material licensees (79,340 workers)

°49% received less than measurable doses

°88% received less 1 rem per year

°99.5% received less than 5 rem per year.

References --

Garcia, L.F., Development of Radiation Protection Guidance for Occupational

J, Exposures, 11th Annual Conference on Radiation Control, 1979 (in press)

and private communication.

Cook, J.R., Cohen, S. and Nelson, D.R., Summary of 1975 Occupational Exposures

for the United States, Abstracts of Twenty-Fourth Annual Meeting of the

Health Physics Society, p. 54 (1979).

D-6
Cool, W.S., Occupational Radiation Exposure at NRC-Licensed Facilities: 1975,

Nuclear Regulatory Commission, NUREG-0419, Washington, D.C. (1978).

D-7

Appendix E

Summary of State and Local Radiological

Health Program Activities

Each year, a report of "State and Local Radiological Health Programs" is

published by the Bureau of Radiological Health to provide information on State

and local efforts in achieving and maintaining comprehensive programs to reduce

or control population exposure to ionizing and nonionizing radiation. The reports also provide a national profile of resources expended and activities performed in certain aspects of radiation control. The most recent report, the

seventeenth in the series, is for fiscal year 1977 [Moats, 1978]. This summary

highlights results from this series of publications.

°In addition to Federal regulation, the States maintain their own regulatory

authority which in many cases is more comprehensive. The number of State

enabling acts for radiation protection regulations from 1950 through 1976 is

shown in Figure 1. States can implement model regulations as provided in

the Suggested State Regulations for Control of Radiation [SSRCR, 1978] with

or without modification, or they can develop the regulations independently.

°State and local expenditures for radiological health activities since 1965

are shown in Figure 2. The total expenditures have dramatically increased

from approximately $6 million in 1965 to nearly $13 million in 1977.

°In 1977, State and local radiation control programs had a total full-time

equivalent of about 600 professional and semi-professional personnel, and

have been gradually, but steadily increasing since 1965 (Figure 2).

°The distribution of expenditures into various program areas is shown in

Figure 3. In recent years (1975-77), program expenditures have been roughly

E-1
E-2
Fig. 2. Total expenditures for state and local radiological health activities.

E-3
CO

<

o

o

CO2 4

g

_i

CO

llJ

Q

2 I Q.X

UJ

ENVIRONMENTAL

SURVEILLANCE

ELECTRONIC PRODUCTS

1

1970 1971 1972 1973 1974 1975 1976 1977

YEAR

Fig. 3. Selected area expenditures for state and local radiological

health activities.

E-4
34% x-ray survey and control

22% radioactive material

18% environmental surveillance

3% electronic products

with the remainder for basic planning and administrative (16%) and other

radiological health activities (7%).

°Figure 4 shows the number of licenses issued by the Nuclear Regulatory

Commission (or formerly AEC) and the 25 NRC Agreement States for byproduct,

source and special nuclear material. As of December 31, 1977, the Agreement States issued 11,473 licenses which represents nearly 57% of the total

licenses issued for such material. In 1977, these States performed 1817

inspections of which 59.6% were found to be in noncompl iance with State

regulations (Table I).

°In 1977, State and local personnel made over 50,000 inspections of x-ray

units, and nearly 10,000 inspections for radioactive materials. For x-ray

units 22% of the inspections found noncompliance with some aspect of State

regulations, while 59% of the initial inspections for radioactive materials

found cases of noncompliance (Table I).

References

Moats, R.A. and Miller, L.A., Report of State and Local Radiological Health

Programs: Fiscal Year 1977, Bureau of Radiological Health, HEW Publication

(FDA)-78-8034 (1978).

Suggested State Regulations for Control of Radiation, prepared by Conference of

Radiation Control Program Directors, Inc., U.S. Nuclear Regulatory Commission,

Environmental Protection Agency, and U.S. Department of Health Education

and Welfare, Food and Drug Administration, Bureau of Radiological Health

(October 1978).

E-5

Table I

Summary of Ionizing Radiation Inspection Activities for 1977

coi^iiiiaLcu nuiiiijcr

of units

acLua 1 numoer

of inspections

percenc or inspections

which found

ilUilUUIlip 1 lariUc

uenta

i

1/1/1 cnn 1 44 , bUU t4 , ouu 1 0 . 0

Medical OP, nnn <1D , uuu 01 0 CI , L

Diagnostic

Therapeutic 4 , J

Nonhealing X-Ray 1 , 1 U 1 03 . 1

Particle Accelerators 1 ITT 1 oo

Kaaioactive naueriais O , /

Nuclear Medicine /I Tnc 4, JUd

Other Medical 910

Industrial 2,585

Other 972

Licensing (Total) 20,239 3,199

NRC 8,766 1,382 43.3

Agreement States 11,473 1,817 59.6

* May be in noncompliance with state regulation for failure to register, film

development, shielding, etc.; no data on equipment noncompliance.

** Initial inspections/reinspections

(1) From Report of State and Local Radiological Health Program Fiscal Year 1977,

HEW (FDA) 78-8034.

E-7
NBS-n4A (REV. 2.8C) U.S. DEPT. OF COMM. BIBLiOGRAPHIC DATA

SHEET fSee instructions)

1. PUBLICATION OR

REPORT NO. NBS SP 603

2. Performing Organ. Report No, 3. Publication Date

March 1981

4. TITLE AND SUBTITLE

Requirements for an Effective National Ionizing Radiation Measurements Program

A Report to the Congress by the National Bureau of Standards

5. PERSON TO CONTACT

Elmer H. Eisenhower, Chief, Office of Radiation Measurements

6. PERFORMING ORGANIZATION (If joint or other thon NBS. see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8. Type of Report & Period Covered

Final

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

10. SUPPLEMENTARY NOTES

Prepared for the U.S. Senate Committee on Commerce, Science, and Transportation, the

Honorable Howard V. Cannon, chairman.

I I Document describes a computer program; SF-185, FlPS Software Summary, Is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a si gnificant

bibHograp^^y or literature survey, mention it here)

This report was prepared for the Senate Committee on Commerce, Science, and

Transportation in response to its recommendation that the National Bureau of Standards

review in cooperation with the Conference of Radiation Control Program Directors the

need for intermediate calibration laboratories for ionizing and nonionizing radiation.

Conclusions relevant to the measurement of nonionizing radiation are presented in a separate report. This report is a description of the elements of an effective support

system for ionizing radiation measurements, an evaluation of current needs in this area

a description of necessary measurement accuracies for specific applications, and a discussion of possible options to improve the support system. The focus is on institutional and technical actions needed to assure the accuracy of ionizing radiation

measurements for the protection of workers and the general public.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate kejy words by semicolons)

Beta rays; Federal and State laboratories; gamma rays; instrument cal ibrations ; intermediate calibration laboratories; ionizing radiation measurements; measurement accuracies; neutrons; radiation dosimetry; radiation protection; radiation standards; x rays,

13. AVAILABILITY

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I I For Official Distribution. Do Not Release to NTIS

[Yl Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402.

Order From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

139

15. Price

$2.25

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