Following the dose calculations for particular operating and accident conditions, the containment design will be chosen to ensure that the Federal Regulations embodied in 10 CFR 20 and 10 CFR 100 are met and, indeed, are bettered.

The annual dose from a PWR from its design basis is 5 mrem/yr although it would be expected to be considerably better than that and values in the region of 0.0063 mrem/yr are likely to be experienced at the site boundary (3b, 6). These values should be compared to the 500 mrem/yr allowed by 10 CFR 20, and they should also be compared to the natural background of 100-600 mrem/yr and the 75-100 mrem/yr of man-made background (see Tables 5.3 and 5.4).

To put these values in perspective it is worth noting that for an increase in altitude of 600 ft there would be an increase in cosmic radiation of approx­imately 5 mrem/yr. Thus the federal regulations allow a release correspond­ing to 25,000 ft,+ the PWR design basis allows 600 ft, but actual emissions are in the range of an equivalent 12-in. increase in altitude!

A fast reactor has no difficulty in bettering the LWR release design figures. Indeed current designs allow for essentially zero release plants during normal operation with on-site storage of fission product wastes.