Document: NUREG-0800
Document ID: bfe08773-10ce-45c6-9767-3cbe51c1726f
Document Type: srp
Title: - 12.4
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070720019.pdf
Revision Date: 2023-06
Chapter: 12
Section ID: 12.3
CFR Part: 
CFR Title: 

Content:
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. Labyrinth shielded access ways and penetrations should be used to minimize radiation steaming 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, Regulatory Guide 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. Regulatory Guide 8.8 provides additional acceptance criteria regarding shielding and isolation in radiation protection design. 12.3-12.4-11 Revision 3 - March 2007 3. Ventilation The ventilation system will be acceptable for radiation protection purposes if the criteria and bases for ventilation rates within the areas covered in SAR Section 12.2.2 will ensure that air will flow from areas of low potential airborne radioactivity to areas of higher airborne radioactivity and then to filters or vents, that the concentrations of radioactive material in areas normally occupied can be maintained in accordance with the requirements 10 CFR 20.1701, and that the dose limits of