title: A review of the (60)Co internal dosimetry at Devonport Royal Dockyard.
abstract: The physico-chemical properties of (60)Co contaminants arising from the UK Naval Nuclear Propulsion Programme (NNPP) pressurised water reactor (PWR) plants have been investigated in order to review individual monitoring requirements at Devonport Royal Dockyard (DRD). This has been achieved through laboratory tests on NNPP primary component samples and interpretation of direct bioassay measurements using internal dosimetry modelling software. Interpretation of lung measurements was completed for two inhalation events involving material originating from a PWR plant and post-primary circuit decontamination. Initial estimates of intake and dose were calculated using International Commission on Radiological Protection default parameter values. However, a good fit could only be achieved by fitting the data to alternative absorption parameters where 90-95% of the material dissolved and absorbed rapidly at a rate of 1 day(-1). As a consequence of this review, a number of improvements have been made to monitoring arrangements at DRD. A minimum of three direct measurements are now taken during the 0-30 day period after an intake, the capability of the Canberra Accuscan has been enhanced and dissolution tests are being carried out by the Health Protection Agency (HPA) on samples taken from PWR plants.
authors.affiliation: Babcock Marine, Devonport Royal Dockyard, Plymouth PL1 4SG, UK. Jenny.Vickers@babcock.co.uk
authors.forename: J M A
authors.initials: JM
authors.lastname: Vickers
authors.forename: R
authors.initials: R
authors.lastname: Collison
authors.forename: R
authors.initials: R
authors.lastname: Collision
mesh_terms: D000396:Air Pollutants, Radioactive / Q000032:analysis*; D003037:Cobalt Radioisotopes / Q000032:analysis*; D006801:Humans; D019570:Inhalation Exposure / Q000032:analysis*; D009688:Nuclear Reactors; D016273:Occupational Exposure / Q000032:analysis*; D011829:Radiation Dosage; D011834:Radiation Monitoring; D011835:Radiation Protection / Q000379:methods*; D011874:Radiometry / Q000379:methods*; D012984:Software; D013051:Spectrometry, Gamma; D006113:United Kingdom
chemical_list: D000396:Air Pollutants, Radioactive; D003037:Cobalt Radioisotopes