Document: NUREG-0800
Document ID: 9f13abda-ee55-4fa1-8276-db55ac2094ef
Document Type: srp
Title: CONTROL ROOM HABITABILITY SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070449.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.4
CFR Part: 
CFR Title: 

Content:
r protecting control room operators under postulated design basis accident conditions. They are not to be interpreted as accept able emergency doses. The dose levels quoted here are derived for use in the controlled plant environment and should not be confused with the conservative dose computation assumptions used in evaluating exposures to the general public for the purposes of comparison with the guideline values of 10 CFR Part 100. The whole-body gamma, thyroid, and beta skin doses are consistent with the recommendations of International Committee on Radiation Protection (ICRP) 26, which were used in the May 21, 1991, revision of 10 CFR Part 20. DRAFT Rev. 3 - April 1996 6.4-6 size, and the available control room protection provisions. The acceptance criteria for the control room habitability system are provided in the regulatory positions of Regulatory Guide 1.78 with respect to postulated hazardous chemical releases in general and in Regulatory Guide 1.95 with respect to accidental chlorine releases in particular. 6. Radiation Hazards The dose guidelines for evaluating the emergency zone radiation protection provisions are as follows: whole body gamma: 50 mSv (5 rem)34 thyroid: 300 mSv (30 rem)35 beta skin dose: 300 mSv (30 rem) 36*37 38 In accordance with GDC 19, these doses to an individual in the control room should not be exceeded for any postulated design basis accident. The whole body gamma dose consists of contributions from airborne radioactivity inside and outside the control room, as well as direct shine from all radiation sources. 7. Toxic Gas Hazards Three exposure categories are defined: protective action exposure (2 minutes or less), short-term exposure (between 2 minutes and 1 hour), and long-term exposure (1 hour or greater). Because the physiological effects can vary widely from one toxic gas to another, the following general restrictions should be used as guidance: there should be no chronic effects from exposure; acute effects, if any,