Routine hand doses vs monitoring regulations at a nuclear power plant

Hand radiation doses to workers at a nuclear power plant were monitored in this study to evaluate compliance with dose limits and to determine whether hand monitoring on a routine basis is necessary. Two hundred in-plant workers at Carolina Power and Light Co.'s H.B. Robinson Steam Electric Generating Plant were monitored with a ring TLD dosimeter on each hand for four months during routine plant operations. Study participants included plant operators, electricians, mechanics, health physics technicians and decontamination personnel. Ring dosimeters were worn, in addition to whole-body TLD dosimeters, at all times workers were in radiation control areas. Hand dosimeters were read on the same monthly schedule as the whole-body dosimeters to ensure correlation of exposure periods. The results of the analysis of hand-dose data obtained for these workers are summarized as follows: (1) No worker's hand dose exceeded 25% of the allowable quarterly dose. (2) Ninety-nine percent of hand doses were less than 600 mrem/month. (3) The highest hand dose observed in any month was 1074 mrem which if received for three months, is below regulatory dose limits and below the dose value where monitoring is required. The highest actual hand dose observed in the last quarter of 1981 was 1335 mrem. (4) Examination of hand dose to whole-body dose ratios revealed that if the whole-body dose limit is approached, hand doses are still below the dose level where monitoring is required. (5) A linear-regression analysis of hand and whole-body dose data provides the ability to predict hand doses from the whole-body doses. From these results, it is concluded that routine monitoring of hand doses is not required at the H.B. Robinson plant. This conclusion should also be applicable to routine operations at other similar nuclear plants.