United States Nuclear Regulatory Commission - Protecting People and the Environment

Air Intrusion into BWR Primary Systems

HPPOS-107 PDR-9111210254

See the memorandum from J. E. Wigginton to R. R. Bellamy (and others) dated April 15, 1983.

The memo states that high radiation in main steam lines is likely from resin or amine injection from condensate demineralizers and not a result of air intrusion. High main steam radiation levels should prompt licensees to note changes in other parameters.

Several facilities had attributed increased main steam line radiation levels to increased N-16 production from free oxygen. The consensus opinion following informal discussions with representatives from General Electric, the Chemical Engineering Branch of NRR, and INPO, however, was that the more likely cause for the increased radiation levels could be resin and/or amine injection from condensate demineralizers.

Since a stagnant, offline demineralizer can produce amines, General Electric recommends a thorough rinse prior to returning an idle bed online. An improperly regenerated resin bed could also be a source of amines. High main steam radiation levels should prompt licensees to note changes in other chemical parameters (i.e., pH, chloride, conductivity) sensitive to potential intrusions and not concentrate solely on fission product analysis.

Regulatory references: None

Subject codes: 5.0, 6.2, 7.1, 10.2

Applicability: Reactors

Page Last Reviewed/Updated Tuesday, June 09, 2015