Document: NUREG-0800
Document ID: 968e9bbe-e8ca-4639-a8d2-f96483377bae
Document Type: srp
Title: - 12.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1219/ML12191A219.pdf
Revision Date: 2023-06
Chapter: 12
Section ID: 12.3
CFR Part: 
CFR Title: 

Content:
utron- gamma sources. The code description file of the Radiation Safety Information Computational Center (formerly the Radiation Shielding Information Center) at Oak Ridge National Laboratory includes most of the codes used by shield designers, which means that the codes have been tested and authenticated for operation but not for reliability and accuracy. Radiation shielding codes vary in complexity and accuracy from the relatively simple point-kernel methods, to the more complex discrete ordinates methods, to the still more rigorous Monte Carlo methods. The staff may use these codes, as necessary, to calculate dose rates for given shield designs and source strengths as a confirmation of the applicant’s method. The applicant’s shielding design is acceptable if the methods are comparable to commonly accepted shielding calculations and if assumptions regarding source terms, cross sections, shield and source geometries, and transport methods are realistic, and specified radiation zones are consistent with the assumed source term and shielding specified in the design. Labyrinth shielded access ways and penetrations should be used to minimize radiation streaming and scatter around shields. Composition of the shielding material should be selected to minimize, to the extent practicable, the potential for the shield itself to become a radiation source (either from activation of the shield material or production of secondary radiation resulting from interactions with the primary radiation). Effective shield design is essential to meeting the criteria that ORE will be ALARA. In addition, RG 1.69 and ANSI/ANS-6.4-1997 provide guidance on the fabrication and installation of concrete shields for occupational radiation protection at nuclear power plants. Acceptability of the shield construction will be based on an indication that the guidance of these documents have been implemented in facility construction, or that acceptable alternatives have been proposed. RG 8.8 provides