Regulatory Guide 3.9
| ML003740214 | |
| Person / Time | |
|---|---|
| Issue date: | 06/30/1973 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| References | |
| RG-3.009 | |
| Download: ML003740214 (2) | |
U.S. ATOMIC ENERGY COMMIIISION
REGULATORY
DIRECTORATE
OF REGULATORY
STANDARDS
REGULATORY
GUIDE 3.9 CONCRETE RADIATION
SHIELDS
A. INTRODUCTION
Section 20.101 of 10 CFR Part 20. "Exposure of Individuals to Radiation in Restricted Areas," states that no licensee shall possess. use, or transfer licensed material in such a manner as to cause any individual in a restricted area to receive a dose in excess of the limits specified therein. Paragraph (c) of § 20.1 provides that licensees, in addition to complying with the requirements set forth in Part 20. make every reasonable effort to maintain radiation exposures as far below the limits specified in this part as practicable.
Concrete radiation shields can be installed in nuclear facilities such as hot laboratories, radiochemical plants, experimental facilities, and nuclear fuel fabrication plants to provide a barrier between personnel and radiation sources for the purpose cf reducing doses of ionizing radiation received by personnel to as low as practicable levels. This guide describes practices for the construction of concrete radiation shielding structures for such nuclear facilities, which are acceptable to the Regulatory staff as methods of complying, in part, with Commission regulations with regard to reducing radiation exposures.
Much of the information included may be applicable to shielding structures for reactors and other nuclear and nonnuclear facilities which require concrete radiation shields.
B. DISCUSSION
Subcommittee ANS- I, Radioactive Materials Handling Facilities and Specialized Equipment.
of the American Nuclear Society has developed a standard presenting requirements and recommended practices for the construction of concrete radiation shielding structures and for certain elements of design that relate to problems unique to this type of structure.
This standard was approved by the American National Standards Comrruttee N]01. Atomic Industry Facility June 1973 GUIDE Deipi. Construction and Operation Criteria.
and it was subsequently approved by the American National Standards Institute (ANSI I on December 2'Z. 1Q'". and designated ANSI NIOI.6.1Q72.
The standard discusses agpegate,.
design of concrete mixtures and forms, placement of concrete, design and installatior of penetrations.
embedments.
metal liners, and penetration plup and outlines testing and quality assurance provistions needed to verify that the desired quality of design and construction has been achieved.
The standard does not include detailed treatments of structural design or determination of shield thickness.
C. REGULATORY
POSITION The requirements and recommended practices contained in ANSI N101.6-1972. "Concrete Radiation Shields,"'
are acceptable for the construction of radiation shielding structures for hot laboratories.
radiochemical plants, experimental facilities, and nuclear fuel fabrication plants subject to the, following:
I. Section 2 of ANSI NI01.6-1q712 lists applicable documents which are intended to supplement this standard.
The specific applicability or acceptability of these listed documents has been or will be covered separately in other regulatory guides or in Commission regulations.
where appropriate.
2. Section A.8 of ANSI N1OI..-Q072 delineates special precautions to be observed in the construction of concrete radiation shields. Where steel or other metals are used as aggrepte t, increase the density of the concrete.
the metal should be of such type that it will not cause hydrogen or other explosive gases to be generated by reaction with the cement. 'Copies may be obtained from the Ameri.-can Nuclear Society. 244 Eait Ogden Avenue. Hinsiale.
litanois 6052
1. USAEC REGULATORY
GUIDES CSS Of Pub e gdnie, n*v be obtained by remterl i nd,cing d",o "a.wd to the US. Atomic Emwrv Comm.es-on.
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3. Section 6.4 of ANSI N I0 .6-1972 does not explain how some d" the variables which are used in the equations for bending moment and tensle strew am to be determined.
Therefore this section should not be used as a substitute for detailed thermal stres analysis in the desigp of temperature reinforcement for control of aacking in specific concrete radiation shields.4. Section 8.7.1 of ANSI NIOI.6-1972 sutes, in part. that rednforcli steel or other means, be provided for tVan erring shoa forces throuOh a wonstructien joint. This requirement Is not sufficient.
Provision skould be made for adequaste meam of transferring shear and other forces through the joint.?C 3.9.2