Regulatory Guide 1.69

Concrete Radiation Shields for Nuclear Power Plants

ML003740235
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Issue date:	12/31/1973
From:	Office of Nuclear Regulatory Research
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RG-1.69
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December 1973 U.S. ATOMIC ENERGY COMMISSION

,)REGULATORY

DIRECTORATE OF .REGULATORY STANDARDS

GU IDE

REGULATORY GUIDE 1.69 CONCRETE RADIATION SHIELDS FOR NUCLEAR POWER PLANTS

A. INTRODUCTION

Section 20.101, "Exposure of Individuals to American Nuclear Society has developed a standard Radiation in Restricted Areas," of 10 CFR Part 20, presenting requirements and recommended practices for

"Standards for Protection Against Radiation," states the construction of concrete radiation shielding that, subject to certain specific exceptions contained in structures and for certain elements of design that relate that section, no licensee shall possess, use, or transfer to problems unique to this type of structure. This licensed material in such a manner as to cause any standard was approved by the American National individual in a restricted Area to receive a dose In excess Standards Committee NIO0, Atomic Industry Facility of the limits specified therein. Paragraph (c) of § 20.1 Design, Construction, and Operation Criteria, and was provides that licensees, in addition to complying with subsequently approved by the American National the requirements set forth in Part 20, should make every Standards Institute (ANSI) on December 22, 1972 and reasonable effort. to maltain radiation exposures as far designated ANSI NI01.6-1972. The standard discusses below the limits specified in that part as practicable. aggregates, design of concrete mixtures and forms, General Design Criterion" 1, "Quality Standards and placement of concrete, design and installation of Records," of Appendix A, "General Design Criteria for penetrations, embedments, metal liners, and penetration Nuclear Power Plants," to 10 CFR Part SO, "Licensing plugs and also outlines testing and quality assurance of Production and Utilization Facilities," requires that provisions needed to verify that the desired quality of structures, systems, and components important to safety design and construction has been achieved. The standard be designed, fabricated, erected, and tested to quality does not include detailed treatments of structural design standards commensurate with the importance of the or determination of shield thickness, but does reference safety function to be performed. Appendix B, "Quality other standards covering structural design.

Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants," to 10 CFR Part 50 requires that

C. REGULATORY POSITION

measures be established to assure design control, material control, special process control, and inspection The requirements and recommended practices and test controls. Appendix B also requires that contained in ANSI NI01.6-1972, "Concrete Radiation activities affecting quality be accomplished under Shields," ' have generally been endorsed by Regulatory suitably controlled conditions. This guide describes some Guide 3.9 as acceptable for the construction of radiation bases acceptable to the Regulatory staff for shielding structures for hot laboratories, radiochemical implementing the above requIrements with regard to the plants, experimental facilities, and nuclear fuel design and construction of concrete radiation shields in fabrication plants. Although written primarily for these nuclear power plants. The Advisory Committee on facilities, the requirements and recommended practices Reactor Safeguards has been consulted concerning this are also considered to be applicable to shielding guide and has concurred in the regulatory position. structures for nuclear power plants subject to the following:

B. DISCUSSION

Subcommittee ANS-11, Radioactive Materiah ' Copies may be obtained from Amercian Nuclear Society, Handling Facilities and Specialized Equipment, of the 244 East Ogden Avenue, Hinsdale, Minois 60521.

USAEC REGULATORY GUIDES Cp of W shed guides may be obtained by request Indlmting the division desired to the US. Atomic Energy Commission. Washington. D.C. 20545.

egultatory Guides am Isued to describe and Wake avalable tO the Public Attention: Director of Regulatory Standmrde. Comments end Kugestions for enothod accptable to the AEC Regulatory etaff of idiPleentning specfIfc Paris Of lrnpXovernants Inthese k am encouraged and should be aent to the Secretary go CornuWMsiOns regulations. to delinet, tihniQue med by the saff in of the Doenrnon. US. Atomic Energy Coinmion. whington. D.C. 20545.

Nyeltueling spcific problasmnw poetubtad accidsnt,, or to Provide guidance to Attention-Chief. Public PromedngsBuff.

appllmnts. Regultory Guidk am not subrtitutes for nreulations and owonlahnm with 9hem b not reluired. Metw&odh end iolutions dfferent from tho at &utIn The guiehs am bIsued in the folloing ten broed divisions:

Uhegu= will be ecuttabie if thy provide a heels for the findlngs equislte 1o U.s uenee or consinuanor ol permlt or licens by the Commission. 1. Pose r Rctors S. Products

2. Reesearch end Test Reectors

7. Transportation

3. Fls nd Materials Facilities a. Occultionlt Health Published guids will be tevised perlodially. asepproprie. to momnmodt 4. EsIronwmtal and Siting 9. Antitrust Rlviw meomsn end w smfelct m information or experence. L atrIel and Plant Protection 1

0. General

1. Section 2 of ANSI NIO.6-1972 lists applicable precautions to be observed in the construction of documents which are intended to supplement the concrete radiation shields. Where metals are used as standaid. These documents, appropriately applied by the aggregate to increase the density of the concrete, tPi user, do provide useful supplementary guidance. metal should be of such type that it will not cau However, this endorsement of ANSI N101.6-1972 does hydrogen or other gases to be generated by reaction with not constitute a blanket endorsement of the contents of the cement. The requirements of Section 4.8A should the documents referenced by the standard. still be met, however, even if a nonreactive metal is used

2. Section 4.2 of ANSI N101.6-1972 states the when as aggregate.

the documents referenced in Section 2 differ from 6. Section 6.4 of ANSI Nl101.6-1972 does not explain project drawings and specifications, the project .how some of the variables which are used in the documents shall govern. This is acceptable provided the equations for bending moment and tensile stress are to resulting margin of safety is not reduced below that be determined. Therefore, this section should not be intended by regulatory requirements or comrhitments used as a substitute for detailed thermal stress analysis in made to regulatory authorities (such as in preliminary the design of reinforcement for control of thermal safety analysis reports). cracking (temperature reinforcement) in specific

3. Section 4.3.3 lists some applied loads to be concrete radiation shields.

considered. Concrete radiation shields for nuclear power 7. Section 8.7.1 of ANSI N101.6-1972 requires, in plants should also consider steady-state and transient part, that reinforcing steel or other means be provided thermal loads, and loads due to postulated missiles. for transferring shear forces through a construction

4. Section 4.3.4 of ANSI NIO.6-1972 states that, joint. Provision should also be made for adequate means when using the working-stress method, where stresses are of transferring other forces through the joint.

increased by temporary loads, the allowable stresses may 8. Section 9.3.4 permits the-inspection of liner welds be increased to those allowed for wind and earthquake with liquid penetrant or magnetic particle methods. In forces. This is acceptable unless such credit is prohibited addition, vacuum box testing would be considered an by regulatory or project criteria. acceptable supplementary method of testing the liner

5. Section 4.8 of ANSI NIi01.6-1972 delineates special welds for leak tight integrity.

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1.69-2.