Limits radiation exposure

Zapponi and Marcello (2006) report an interesting study, which says that if our low level adaptive response were to occur at just the level of the allowable radiation exposure limit, then the authors calculate that there is still some risk at or possibly below that level. To be a trae adaptive response one would want to go below the level where there is significant risk. As these data point out, this level may be difficult to calculate. Moreover, it may be easy to interpret data in a variety of different ways. 

Many of the recommendations of the ICRP and other radiation protection groups regarding radiation exposure have been incorporated into regulatory requirements by various countries. For the U.S. Department of Energy facilities, radiation exposure limits are found in Title 10, Part 835 of the Code of Federal Regulations (10CFR835). Table 3.1 provides a summary of the dose limits for occupational external exposures. 

Radiation exposure limit/week = 2 mrem/week... 

Radiation exposure limits are set at such levels that nonstochastic biological effects do not occur. 

The system permits sampling during reactor operation, cooldown, and post-accident conditions without requiring access to the containment. Remote samples can be taken of fluids in high radiation areas without requiring access to these areas, thus permitting personnel to remain within their radiation exposure limits. The sampling system performs no safety function (See CESSAR-DC, Section 9.3.2.1). 

Operating personnel radiation exposure limit <1 Sv/year... 

Deposition of corrosion products in a circulating AT liquid metal system is important for three reasons. First, the degradation of heat transfer perfonmance of heat exchangers must be predicted. Second, radiation exposure limits for maintenance in certain areas of nuclear reactor systems that transport and deposit radioactive species must be controlled. Third, the tendency for all deposits to become detached by thermal shock or flow perturbations must be known since there is concern that these types of debris could block critical coolant channels. It is therefore valuable, when possible, to monitor reactions involving deposition as well as dissolution. 

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