Determination of Prior Occupational Dose

Section 340 Section 340.250  Determination of Prior Occupational Dose a)         For each individual who may enter the licensee's or registrant's restricted area and is likely to receive, in a year, an occupational dose requiring monitoring pursuant to Section 340.520 of this Part, the licensee or registrant shall determine the occupational radiation dose received during the current year prior to allowing such individual to enter a restricted area.  In order to comply with this requirement, a licensee or registrant may accept, as a record of the occupational dose that the individual received during the current year, a written signed statement from the individual, or from the individual's most recent employers for work involving radiation exposure, that discloses the nature and the amount of any occupational dose that the individual may have received during the current year.  To accomplish this, a licensee or registrant may use the NRC Form 5 or submit equivalent information. AGENCY NOTE:  Licensees and registrants also should attempt to obtain the records of cumulative occupational radiation dose. b)         Prior to permitting an individual to participate in a planned special exposure, the licensee shall: 1)         Determine the cumulative occupational radiation dose. A)        In order to comply with this requirement, a licensee may accept, as the record of cumulative radiation dose, an up-to-date NRC Form 4, or equivalent, signed by the individual and countersigned by an appropriate official of the most recent employer for work involving radiation exposure, or the individual's current employers (if the individual is not employed by the licensee); and B)        Obtain reports of the individual's dose equivalent for the time period subsequent to that included in NRC Form 4, or equivalent, as specified in subsection (b)(1)(A) of this Section.  Such reports shall be signed by the individual and countersigned by an appropriate official of the most recent employers for work involving radiation exposure, or the individual's current employers (if the individual is not employed by the licensee).  The information shall be recorded on NRC Form 5, or equivalent. 2)         Determine the internal and external doses from all previous planned special exposures. 3)         Determine all doses in excess of the limits received during the lifetime of the individual, including doses received during accidents and emergencies. c)         The licensee or registrant shall record the exposure history, as required by subsections (a) and (b) of this Section, on NRC Form 4 or 5, or equivalent, as applicable, or other clear and legible record containing all of the information required on that form. 1)         The form or record shall show each period in which the individual received occupational exposure to sources of radiation and shall be signed by the individual who received the exposure.  For each period for which the licensee or registrant obtains reports, the licensee or registrant shall use the dose shown in the report in preparing the exposure history.  For any period in which the licensee or registrant does not obtain a report, the licensee or registrant shall place a notation on the exposure history indicating the periods of time for which data are not available. 2)         For the purpose of complying with this requirement, licensees or registrants are not required to reevaluate the separate external dose equivalents and internal committed dose equivalents or intakes of radionuclides assessed before January 1, 1994.  Further, although occupational exposure histories obtained and recorded before January 1, 1994, would not have included effective dose equivalent, such histories may be used in the absence of specific information on the intake of radionuclides by the individual. d)         If the licensee or registrant is unable to obtain a complete record of an individual's current and previously accumulated occupational dose, the licensee or registrant: 1)         When establishing administrative controls pursuant to Section 340.210(g) of this Part for the current year, shall assume that the allowable dose limit for the individual is reduced by 12.5 mSv (1.25 rem) for each calendar quarter for which records were unavailable and the individual was engaged in activities that could have resulted in occupational radiation exposure; and 2)         Shall not authorize the individual to receive any planned special exposures. e)         Records shall be retained in accordance with the requirements of Section 340.1140(a) of this Part.