Regulatory Guide 8.28
| ML003739382 | |
| Person / Time | |
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| Issue date: | 08/31/1981 |
| From: | Office of Nuclear Regulatory Research |
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| RG-8.28 | |
| Download: ML003739382 (6) | |
U.S. NUCLEAR REGULATORY COMMISSION Augut 1981 REGULATORY GUIDE
OFFICE OF NUCLEAR REGULATORY RESEARCH
REGULATORY GUIDE 8.28 (Task OH 804-4)
AUDIBLE-ALARM DOSIMETERS
A. INTRODUCTION
where to stand while doing a job to receive the least expo sure. Although a survey with a survey meter is required Section 20.201, "Surveys," of 10 CFR Part 20, "Stand before work starts, the audible-alarm dosimeter can help a ards for Protection Against Radiation," states that licensees worker recall the locations of "hot spots" and help the must make or cause to be made such surveys to evaluate worker better locate the centers and boundaries of any radiation hazards as may be necessary for the licensee to "hot spots."
comply with the regulations of Part 20. Section 20.202,
"Personnel Monitoring," requires the use of appropriate In medical institutions, audible-alarm dosimeters have personnel monitoring equipment to determine whether any been found to be very useful as a training aid to demonstrate radiation dose is being or has been received. Licensees where and when radiation exposure is being received.' In sometimes supplement such monitoring equipment with certain situations, moving to a slightly different location electronic pocket dosimeters that have an audible alarm to will greatly reduce exposure. Thus, audible-alarm dosimeters warn workers that they may be receiving more exposure can be useful in programs to maintain occupational exposures to radiation than they had expected or had planned.
to radiation as low as is reasonably achievable (ALARA).
This guide discusses a program for the appropriate use of In industrial radiography, an audible-alarm dosimeter audible-alarm dosimeters, including certain conditions can provide warning to a radiographer that he or she is under which they should not be relied upon to perform approaching an exposed source. Ideally, the radiographer's their intended function. The guide also discusses perform survey meter should have provided a warning, but, in many ance specifications that the dosimeters should meet if they radiography overexposures, the radiographer did not use are used. the survey meter or else used the meter but did not draw appropriate conclusions from the meter readings.
In this guide, the term "audible-alarm dosimeters" refers to electronic dosimeters that alarm when either a preset In low-level waste disposal, an audible-alarm dosimeter integrated exposure or a preset exposure rate is reached;
can quickly warn a worker that a particular package is more these dosimeters generally sound a short "beep" every time than normally radioactive and should receive especially an exposure of I milliroentgen is accumulated. The term cautious handling.
audible-alarm dosimeters also includes "chirpers," those devices that sound a brief "chirp" or "beep" every time Audible-alarm dosimeters are not generally substitutes some small exposure is received; these "chirpers" usually for conventional survey meters:2 The dosimeters provide a emit a hundred or more chirps per milliroentgen.
complementary function. They provide some redundancy or
"defense in depth" where (1) the operator fails to perform
B. DISCUSSION
Several types of work lend themselves to the advanta Joel E. Gray, "Radiation Awareness and Exposure Reduction geous use of audible-alarm dosimeters. For example, with Audible Monitors," American Journal of Roentgenology, vol.
133, p. 1200, December 1979.
audible-alarm dosimeters may be effectively used during nuclear power plant maintenance operations. The alarm can 2An exception to this statement, however, can be found in warn workers that they are being exposed unexpectedly. Standard Technical Specification 6.12.1, "High Radiation Area,"
for nuclear power plants. The specification allows an audible-alarm The alarm can tell a worker who has reached a preset dose dosimeter to be substituted for a survey meter after the dose rates in level to leave the area. The alarms can also tell a worker the area have been measured with a survey meter and the workers in the area have been informed of the measured dose rates.
USNRC REGULATORY GUIDES
Comments should be sent to the Secretary of the Regulatory Guides are issued to describe and make available Commission, public methods acceptable to the NRC staff of Implementing to the U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Docketing and Service Branch.
specific parts of the Commission's regulations, to delineate niques used by the staff in evaluating specific problems or tech The guides are issued In the following ten broad divisions:
lated accidents or to provide guidance to applicants. Regulatorypostu Guides are not substitutes for regulations, and compliance 1. Power Reactors with 6. Products them is not required. Methods and solutions different from 2. Research and Test Reactors 7. Transportation out in the guides will be acceptable if they provide a basisthose set 3. Fuels and Materials Facilities for findings requisite to the issuance or continuance of a permit the 8. Occupational Health or 4. Environmental and Siting 9. Antitrust and Financial Review license by the Commission. 5. Materials and Plant Protection 10. General This guide was issued after consideration of comments received Copies of issued guides may be purchased at the current Government the Public. Comments and suggestions for improvements from in these Printing Office price. A subscription service for future guides in spe guides are encouraged at all times, and guides will be revised, cific divisions Is available through the Government Printing Office.
appropriate, to accommodate comments and to reflcct new as Informa Information on the subscription service and current GPO prices may tion or experience. be obtained by writing the U.S. Nuclear Regulatory Commission, Washington, D.C. 20555, Attention: Publications Sales Manager.
a survey. (2) the operator fails to make a fully adequate Conversely, some medical users complained that the dosim survey, or (3) the survey meter has malfunctioned, unknown eters were too loud and had to be modified to reduce the to the operator. An audible-alarm dosimeter is especially sound level. Certain dosimeter models did not survive drop asefuLl when workers cannot hold survey meters because tests of 4 to 8 feet, but other models did. Certain models they need both hands to perform a job or when workers had weak mounting clips or switches that were so easily cannot c-ntinually look at the survey meter because the accessible that they were inadvertently moved. These operation they are performing requires them to look defects should be easily apparent to a potential purchaser clsewhere. The alarm dosimeter also provides continuous and therefore avoidable. Thus, it must be concluded that feedback to users about where and when they are receiving although the dosimeter models tested are not perfect and a radiation dose. Used in the manner described above, cannot meet all environmental conditions, a potential alarm dosimeters can be a valuable part of a licensee's purchaser can find models that will be adequately reliable educational program or ALARA program and can comple for a wide variety of uses. Thus, the NRC staff believes that rmient the conventional survey meter. many commercially available audible-alarm dosimeters are adequate to perform a valuable function if they are not The main difficulties that arise with the use of audible subjected to inappropriate use as described in the regulatory alarm dosimeters are related to their occasional unreliability position.
and their improper use. A worker wearing an audible-alarm dosimeter that has stopped working may have a false In addition to the results of these studies, the American indication of safety. Unaware that the audible-alarm National Standards Institute (ANSI) Committee N13, dosimeter is not working, the worker may neglect other "Radiation Protection," sponsored by the Health Physics precautions such as performing radiation surveys. In such a Society, has developed a standard on acceptable performance case, the worker could be unaware of radiation exposure specifications for audible-alarm dosimeters. The standard levels. The possibility of depending on an alarm dosimeter entitled "Performance Specifications for Pocket-Sized that is not working can be diminished by using a modem Alarming Dosimeters/Ratemeters" was approved by ANSI
audible-alarm dosimeter designed for severe industrial use in April 1981 and designated ANSI N13.27. 4 Regulatory and by following procedures for avoiding misuse. These Guide 8.28 endorses, with one exception, the performance subjects are discussed in the regulatory position. specifications for dosimeters indicated in this standard.
To evaluate the reliability of audible-alarm dosimeters
C. REGULATORY POSITION
now commercially available, the NRC contracted with Battelle-Pacific Northwest Laboratories for performance The NRC staff approves of the use of audible-alarm I
testing of such dosimeters. The results of these tests are dosimeters if they are used as part of a carefully controlled reported in NUREG/CR-0554, "Pocket-Sized Electronic program that ensures proper use of the alarm dosimeters.
Dosimeter Testing," 3 January 1979. written by Oscar The program should contain guidance on the selection of Mulhem, William Bartlett, and C. I). Hooker, and NUREG/ appropriate dosimeters, their proper use, and what consti CR-1452, "Further Testing of Pocket-Sized Electronic tutes misuse.
Dosimeters," 3 April 1980, written by Robert A. Fox, C. D.
Hooker. and B. T. Hogan. The authors of NUREG/CR-1452 1. Selection of Appropriate Dosimeters have prepared another report, NUREG/CR-2019, "Third Phase of Pocket-Sized Electronic Dosimeter Testing," that The radiation protection staff should be given the is expected to be published in August 1981. The authors of responsibility for selecting dosimeters appropriate for the these reports were rather critical of the performance of the conditions to be encountered.
audible-alarm dosimeters that they tested. A careful reading of their conclusions reveals that the failure of any dosimeter Audible-alarm dosimeters should meet the performance models to survive the water-immersion test and audibility specifications indicated in ANSI N13.27-1981, "Perform test under very noisy conditions was an important factor in ance Specifications for Pocket-Sized Alarming Dosimeters/
reaching their conclusions. Ratemeters," except that dosimeters to be used in quiet locations need not meet the loudness specification of the It appears that the criteria against which the instruments standard (paragraph C.2). Only dosimeters designed for were tested were unduly stringent and that the Battelle severe industrial use (those that can pass the 1.2 meter drop testers may be requiring more of the instruments than test described in paragraph A.3 of the standard) should be is necessary for certain uses. It is difficult to justify requiring used.
the instruments to operate after immersion in water if the instruments will not be used in heavy rain or if their being Audible-alarm dosimeters with an appropriate chirp rate dropped in water is unlikely. The sound levels may not be should be se;ected. Thus, audible-alarm dosimeters that will adequate for many noisy industrial environments and not chirp excessively at the anticipated exposure levels should consequently should not be used in these environments. be selected. For example, dosimeters that chirp 50 times or more per I milliroentgen dose are not suitable for use in
3 Copies are available at current rates through the Distribution industrial radiography or nuclear reactor maintenance Services Section, Division of Technical Informjation and Document Control, U.S. Nuclear Regulatory Commission, Washington, D.C. 4
20555, or from the National Technical Information Service, 5285 Copies are available from the American National Standards Port Royal Road, Springfield, Virginia 22161. Institute, Inc., 1430 Broadway, New York, New York 10018.
8.28-2
because they will chirp so frequently that they will be (4) Dosimeter Affected by Chemicals. Alarm dosim annoying to the user. eters should not be used when a salt or corrosive chemical laden atmosphere is present. Salt water quickly caused all
2. Proper Use audible-alarm dosimeters tested to malfunction.
The radiation protection staff should be responsible for c. Each day, before use, audible-alarm dosimeters should assigning audible-alarm dosimeters only when the working be tested for adequate battery strength and should be environment is suitable for their use and when the users checked with a radiation source for proper operation.
have been instructed in proper use of the dosimeters and can be trusted to use the dosimeters as instructed. Proper d. Care should be taken to avoid dropping alarm dosim use includes the following: eters. If a dosimeter is dropped, its proper operation should be verified with a radiation source before using a. Audible-alarm dosimeters should not be substituted the dosimeter again.
for a survey meter. 2 Instead, they are a complementary warning device. 3. Misuse of Dosimeters b. A program should prohibit the use of a dosimeter in The program should permit the radiation protection the following adverse situations: staff to take the dosimeter away from a worker immediately on observing that the worker is misusing the dosimeter
(1) Alarm Inaudible. Alarm dosimeters should not (e.g., using the alarm dosimeter as a substitute for the be used when the alarm may not be heard, such as (a) in a survey meter in violation of operating procedures or hardl high noise environment, (b) when the user has a pronounced ing the alarm dosimeter roughly). In addition, the progrim hearing loss, (c) when the user is wearing mufflers over should allow any worker to discontinue using an audibh the ears, or (d) when the sound from the dosimeter would alarm dosimeter if the worker finds use of the dosimeter be muffled by heavy clothing worn over the dosimeter.
inappropriate. The use of alarm dosimeters should alvavs be optional, never mandatory.
(2) Alarm Too Loud. Audible-alarm dosimeters with a loud sound level should not be used in quiet environ
D. IMPLEMENTATION
ments where the dosimeter might create a disturbance or become annoying, thereby causing the user to shut it off. This section provides information to applicants on thfe NRC staff's plans for using this regulatory guide.
(3) Dosimeter Soaked with Water. Alarm dosimeters should not be used when immersion in water or soaking of If an applicant plans to use audible-alarm dosimeters as the dosimeter, such as from rain, is possible. Tests have part of the radiation protection program, the selection and shown that immersion in water stops all alarm dosimeters use of the audible-alarm dosimeters will be evaluated on the from working. Complete drying of dosimeters and replacing basis of this guide unless the applicant has proposed an the batteries will allow some but not all dosimeters to acceptable alternative method for complying with the resume proper operation.
specified portions of the Commission's regulations.
8.28-3
VALUE/IMPACT STATEMENT
I. THE ACTION 1.3.2 Industry
1.1 Description The guidance will allow licensees (including industrial radiographers, nuclear power plant personnel, low-level The action, issuance of Regulatory Guide 8.28, "Audible radioactive waste disposal facility personnel, and others) to Alarm Dosimeters," is intended to provide guidance on the select an audible-alarm dosimeter suitable for their needs selection of reliable audible-alarm dosimeters and on the and to avoid using dosimeters that are not likely to perform appropriate use of such dosimeters by industrial radiog adequately. The guidance will also alert licensees to situations raphers, nuclear power plant workers, and others as a where the use of audible-alarm dosimeters is not appropriate.
supplemental warning of exposure to radiation. This will assist licensees in conducting adequate surveys and using appropriate personnel monitoring equipment.
1.2 Need The guidance will also provide dosimeter manufacturers At times in the past, industrial radiographers have with criteria to use in designing suitable dosimeters.
attempted to improve safety by using audible-alarm dosim eters. For the most part these attempts were unsuccessful An impact of publishing performance specifications is for two reasons. First, commercially available audible-alarm that the market potential for dosimeters not meeting the dosimeters often were not rugged enough to operate specifications will be greatly reduced. Manufacturers of reliably under adverse field conditions.* Second, radiog those dosimeters would probably have to redesign their raphers using these audible-alarm dosimeters placed less dosimeters.
reliance on the use of survey meters. A survey meter reading not heeded coupled with the radiographer depending 1.3.3 Workers on an audible-alarm dosimeter that was not working has often created a dangerous situation. The use of reliable audible-alarm dosimeters can be beneficial to workers if good dosimeters are used in appro The guidance is intended to allow licensees to select priate situations. Warning of high radiation levels can reliable audible-alarm dosimeters and to provide dosimeter reduce the frequency of radiation overexposures and can manufacturers with criteria they may use in designing their reduce occupational exposure to radiation when radiation products. Because reliability and use of alarm dosimeters levels are higher than expected.
are so interconnected, both performance criteria and pro grams for dosimeter use will be treated in the same guide. 1.3.4 ANSI
1.3 Value/Impact The draft guide on audible-alarm dosimeters was based on the May 11, 1979, version of a draft standard developed
1.3.1 NRC Operations by the American National Standards Institute (ANSI)
Committee N1 3, "Radiation Protection," sponsored by the Approximately one man-year of staff time has been Health Physics Society. The development of NRC guidance required to develop and review the guide. A technical proceeded in parallel with the ANSI standard, but the NRC
assistance contract ($77,000) with Battelle-Pacific North did not wait for issuance of the ANSI standard before west Laboratories was awarded for testing commercially publishing the draft guide for public comment.
available alarm dosimeters. Their first report was received in March 1979 and published as NUREG/CR-0554, "Pocket The active guide, Regulatory Guide 8.28, endorses, with Sized Electronic Dosimeter Testing."** A followup report one exception, ANSI N13.27-1981, "Performance Specifi was published in April 1980 as NUREG/CR-1452, "Further cations for Pocket-Sized Alarming Dosimeters/ Rate meters,"
Testing of Pocket-Sized Electronic Dosimeters."** A final that was approved by ANSI in April 198 1.
report, NUREG/CR-2019, "Third-Phase of Pocket-Sized Electronic Dosimeter Testing," is expected to be published
2. TECHNICAL APPROACH
in late 1981.
Comments from some users were given in Attachment 1 to the 2.1 Value/Impact of the Use of Audible-Alarm Dosimeters value/impact statement issued with Draft Guide OH 804-4, "Audible in Industrial Radiography Alarm Dosimeters," in August of 1979. Co ie available for public inspection or copying fora fee in teU.. Nuclear Regulatory Commission Public Document Room, 1717 H Street NW., Washing It is believed that the careful use of audible-alarm ton, D.C.
dosimeters in industrial radiography would reduce workers'
Copies are available at current rates through the Distribution collective dose, but it is not possible to estimate the size of Services Section Division of Technical Information and Document the reduction. In some cases increased dose could result Control, U.S. Nuclear Regulatory Commission, Washington, D.C.
20555, or from the National Technical Information Service, 5285 from reliance on an alarm dosimeter that is not working in Port Royal Road, Springfield, Virginia 22161. place of a survey meter.
8.28-4
The alarm dosimeter would be of use in avoiding accident would not be safe and that it should help licensees select situations. It is not known how much of the collective dose dosimeters having adequate performance characteristics in radiography is caused by accidents, but it is probably no for their intended use where their use is desirable.
more than 10 percent of the total dose.
2.3 Value/Impact of the Use of Audible-Alarm Dosimeters Thus, accidents by NRC-licensed radiographers could in Other Activities account for 310 of 3100 man-reins. (The collective dose resulting from overexposures totals about 100 man-reins An informativc description of the use of audible-alarm annually, but not all accidents lead to overexposures.) dosimeters in medical institutions has been written by Dr.
Assuming the alarm dosimeters could reduce the 310 Joel E. Gray ("Radiation Awareness and Exposure Reduc man-reins by 50 percent, the dosimeters might save 155 tion with Audible Monitors," American Journal of Roent man-reins per year. genology, vol. 133, p. 1200, December 1979). Gray found that audible-alarm dosimeters were useful as a training aid To accomplish this saving, the industry would have to to demonstrate where and when radiation exposure is being buy 1500 alarm dosimeters per year (assuming a 2-year life)
received.
at a cost of $100 per unit. Thus, the annual equipment cost would be $150,000 per year. The cost of maintaining the
3. PROCEDURAL APPROACH
dosimeters would be at least $50,000 per year for a total cost of $ 200,000 per year. 3.1 Procedural Alternatives This cost might save 155 man-reins that might be caused There are four possible procedural approaches for by accidents and perhaps more in normal operations.
publishing this guidance:
2.2 Value/Impact of the Use of Audible-Alarm Dosimeters a. Regulation in Nuclear Power Plant Maintenance or Repair b. Regulatory guide developed by the staff c. Regulatory guide adopting an ANSI standard Audible-alarm dosimeters generally have a different d. NUREG-series report or other less formal presentation function in nuclear power plant maintenance or repair than of the criteria in industrial radiography. Rather than warning of an accident, they warn when a preset dose limit has been
3.2 Value/Impact of Procedural Alternatives reached. As such, they allow a more precise measurement of a worker's exposure during the course of a job than A regulation is not a suitable alternative for publishing would otherwise be possible. Thus, the dosimeters allow the this guidance because the use of alarm dosimeters is optional.
worker to work in the radiation area without receiving an overexposure. Used in this way, the purpose is not to A regulatory guide is the recommended procedural reduce the collective man-rem from a job, but to spread it alternative because a guide allows considerable flexibility in over enough workers that an overexposure to anyone would its application.
be avoided. The dosimeter's value to the licensee is that it allows better use of manpower.
Regulatory Guide 8.28. endorsing an ANSI standard has been selected because the ANSI standard represents the A savings of man-reins is possible during maintenance or work of a group of experts on the performance of these repair work when the size of the area being worked in is instruments.
large, when the dose rates in the area vary, and when the area contains "hot spots." An audible-alarm dosimeter with a "chirper" type alarm will immediately warn a worker that A NUREG-series report or other less formal presentation has not been selected because the performance criteria and he or she is in an area with high doses rates. This warning recommendations on the use of alarm dosimeters would allows avoidance of the area when possible. Unfortunately, really be guidance and not background information. The the savings in collective dose from this application will subject also seems important enough to warrant issuance of depend so strongly on the particular situation that an a regulatory guide.
estimate of dose savings cannot be made for the general situation. It is only possible to calculate a savings when the specific circumstances of an individual situation are known.
4. SUMMARY AND CONCLUSIONS
The value of this guide to the licensee is that it should prevent the use of audible-alarm dosimeters where their use Regulatory Guide 8.28 has been prepared. It endorses, with certain exceptions, ANSI N13.27-1981.
8.28-5
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