Regulatory Guide 8.4
| ML003739448 | |
| Person / Time | |
|---|---|
| Issue date: | 02/26/1973 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-8.4 | |
| Download: ML003739448 (2) | |
2/26/73 U.S. ATOMIC ENERGY COMMISSION
REGULATORY GUIDE
DIRECTORATE OF REGULATORY STANDARDS
REGULATORY GUIDE 8A
DIRECT-READING AND INDIRECT-READING
POCKET DOSIMETERS
A. INTRODUCTION
requirements [§20.202(b)]. Specific performance standards for pocket dosimeters used for area The Atomic Energy Commission's "Standards for monitoring are not included in this guide at this time.
Protection Against Radiation," 10 CFR Part 20, These latter standards are expected to be less stringent contains several regulations regarding the measurement than personnel monitoring standards.
of X- or gamma radiation from sources external to the body. Such measurements 're required by § 20.202(a)
B. DISCUSSION
"Personnel Monitoring," to determine compliance with limits specified in § 20.101, "Exposure of Individuals to Subcommittee N13.5 on Performance of Portable Radiation in Restricted Areas," and § 20.104, Survey Meters and Personnel Dosimeters, of the
"Exposure of Minors." with results recorded as required American National Standards Committee N13 on by § 20.401, "Records of Surveys, Radiation Radiation Protection, has developed a standard which Monitoring, and Disposal." Such measurements are also provides performance specifications for direct-reading needed to determine incident reporting requirements as and indirect-reading pocket dosimeters for X- or famma specified in § 20.403, "Notification of Incidents," radiation. The standard, ANSI N13.5-1972, was whether the measurements are made during the actual approved by the American National Standards Institute incidents or during a pust-incident invcstigation. The on December 9, 1971.
Commission's reguiation "Licenses for Radiography and Radiation Safety Requirements for Radiographic As a performance standard, N13.5-1972 does not Operations," 10 CFR Part 34, contains a provision provide detailed guidance on the use of pocket which requires pocket dosimeters or pocket chambers as dosimeters. However, certain details such as the measurement devices for personnel monitoring .tontrol maximum intervals for leak rate and calibration/response I§ 34.33j. These measuiements are concerned with the testing are directly related to performance standards in dose to personnel. the. context of satisfying Commission regulations.
Therefore, guidance in this document is not limited to Al th qtpgh compliance with these regulations the standards appearing in N 13.5-1972 but also includes necessitates measurements of X- and gamma radiation, recommended intervals for such testing.
the Commission has not prescribed performance standards for the instrumentation that may be used. This Many Commission licensees employ film dosimetry guide provides such standards for direct-reading and to satisfy the personnel monitoring requirements of 10
indirect-reading pocket dosimeters used for personnel CFR Part 20. However, film used in mixed fields of dose or dose rate measurements pursuant to §§ 20.101, gamma and neutron radiation may provide an
20.104, 20.202(a), 20.401, 20.403, and 34.33. incomplete indication of the dose equivalent due to neutrons. This difficulty arises when a significant Other regulations in 10 CFR Part 20 are concerned fraction of the dose equivalent is due to intermediate with area monitoring as necessary to demonstrate compliance with permissible levels of radiation in 'Copies may be obtained from the American National unrestricted areas J§ 20.105(b)(2)J, survey Standards Institute, Inc., 1430 BToadway, New York, New York requirements I§ 20.2011, and area classification 10018.
USAEC R.GULATO"V GUIDES Copie of published qu.oe may be obtained by rebuest indating the divisions desired to the US. Atomic Eneis- Comrinio.l tlhington. ODC. 20545.
Regulat*ory Guod el rr issued to deio be and niehe ivailable to the public Atention Director of Regulatery Standards Comments and tuwantion$ for etnods ecmptable to the AlCt:CftlilJaoly ostall of I*OWlermniln ipecifiociparone iof flwaiteis nti in tiell guidn awe entcti olrgdand titould be tnt to the Secrelary Ito LOns*o.toln ma1lat0 . i' doellrote tainoques usted by the staff in
-6o, of the CoMMmuitoni. U.S. Atomic Energy Cormr*ono. Wahington, 0.C. 20545.
sevluating apecttic poooblertn a? posiarlostiel accodoeiit, v, to trovide gsuidien to A too ion Chief. Public PrOw~ig;~n Staff.
apaittnit Ne rumini, aer not wbobtat..tai fix regutatbortt and comnplienes (ltr vith them is ~*u iequiieo. Methods d toblutio difn Mnt hfrom thate tt out in The guidsm awt iud in the followting ten broadodvisiont:
the suids *III be ocomteptbir It ttse provide a basisto. thewfindong reqijisite to rhe imsoiace or onwwa,,u Of aer*
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oVcne na the conmrissidoli l by 1. Powe React1or 6 Products
2 Resmidh and Test Reactors 7, Transporta*lon
3. Fkantd Materiots Facilitie S. Occupaetonal Health Pubtivhoid etudes will be revitat piood*,cal;y. as appioprate tO aoM.oumoNdata 4 Envoreneiatal and Siting 9 Antitrust Review co'OntInts ond II refkiactneonw 1i nrintiwto a"Wei.elit. 5 Ma01terias tand Plant Protection to Ganeral
neutrons of insufficient energy to produce discernible (i) 3 months if the dosimeters are us :d as tihe recoil proton tracks in dosimetric fim or when tracks primary method for compliance with § § 20.2012(a) and are masked by blackening of the film due to gamma 20.401 of 10 CFR Part 20, or for compliance with radiation. To overcome these problems, licensees often § 34.33 of 10 CFR Part 34; or employ an indirect measurement technique which (2) 6 months if the dosimeters are used to utilizes gamma pocket dosimeters to determine the supplement the primary method for compliance with the neutron dose equivalent as well as the gamma exposure. above sections of the regulations.
This technique requires knowledge of the intermediate neutron-to-gamma ratio in the area of interest. Under 2. Rejection certain conditions this method is a useful personnel monitoring procedure. If the dose equivalent rate due to A dosimeter should be rejected if it fails t. comply intermediate neutrons and the gamma exposure rate are with either of the following:
determined separately and in a technically sound a. ANSI N13.5-1972, Section 9;
manner, and if the neutron-to-gamma ratio is essentially b. The calibration/response test result should not constant during the period(s) of exposure, the exceed +/-1 0% of an exposure from a source traceable to Commission will accept the method as complying with the National Bureau of Standards.
the regulations. Therefore, guidance on the method is included in this document. 3. Mixed Radiation Fields
C. REGULATORY POSITION
American National Standard N13.5-1972, Direct- or indirect-reading pocket dosimeters may
"Performance Specifications for Direct Reading and be used in a mixed neutron/gamma radiation field to Indirect Reading Pocket Dosimeters for X- and Gamma comply with the personnel monitoring and record Radiation," provides an acceptable basis for the keeping requirements of 10 CFR Part 20, § § 20.202(a)
selection and continued use of direct-reading or and 20.401, provided that all of the following conditions indirect-reading pocket dosimeters, as defined in Section are met:
2 of N13.5-1972; as instruments for measuring X- and a. The neutron dose equivalent rate and the gamma radiation2 pursuant to the requirements of §§ gamma exposure rate at the point of personnel exposure
20.202(a) and 20.401 of 10 CFR Part 20, and § 34.33 are known from separately made determinations;
of 10 CFR Part 34, as supplemented by the following: b. The neutron-to-gamma ratio is essentially constant during the period of personnel exposure;
1. Testing c. The degree of response of the dosimeter to the Direct- or indirect-reading pocket dosimeters used as neutron flux density is known.
personnel monitoring equipment should be tested for If the response to the neutron flux density is calibration/response and leak rate: negligible, the gamma exposure indicated by the a. Prior to initial use; dosimeter may be accepted. To determine the neutron b. After subjection3 to possible damage from dose equivalent, multiply the indicated gamma expoure dropping or other causes; by the neutron-to-gamma ratio.
c. At maximum testing intervals of: If the response to the neutron flux density is significant, the actual gamma exposure should be
"2 Any pocket dosimeter meeting the performance standards obtained by subtracting the neutron response from the specified in ANSI N13.5-1972 is acceptable to the AEC indicated gamma exposure. To determine the neutron Regulatory staff for X- or gamma radiation measurements made dose equivalent, multiply the actual gamma exposure by pursuant to § § 20.105(b)(2), 20.201, and 20.202(b) of 10 CFR the neutron-to-gamma ratio.
Part 20.
'Dosimeters should be worn in pairs when used as the primary method of personnel monitoring required by the regulations.
9.4-2