BA SUBJECT: Nose Swipe Data the action level equates to 112.6 pci per filter paper. What is done is to take the gross alpha activity in counts per minute of the filter paper using a field survey instrument. If a certain number of counts is obtained, it equates _to an approximate concentration in the air of radioactivity and triggers additional measurements, i.e., nose swipes. The action level at Enewetak is conservative, thus many nose swipes are taken when conditions such as have apparently existed recently occur-- an apparent abundance of short-lived natural alpha-emitting isotopes, probably radon from sea water. The field instrument does not discriminate among alphas from plutonium, americium or radon or any other nuclide. That the activity on the filter paper is short-lived is borne out by the fact that no activity is measured a few days later in the laboratory. 3. The aspect of these messages that should be emphasized, in my opinion, concerns the statement about a programming error that existed for close to four months. surprising that an error occurred; however, It is not it is surprising that the fact that the Ys in the air sample measurement valves during that period apparently did not provoke a bit of curiosity on She part of someone as to whether they were real or not, or “Gua—te the probable cause, aa ete may be that it did, and they couldn't find the reason until this time had elapsed.) Abrupt changes are important to rad-safe people from the standpoint of what caused them-- Are they @) ae _ : oe wae _. =e. ae Terr: ‘ we . = . 4 ~ t