Technical Assistance Request Concerning Posting per 10 CFR 34.42 and Surveys per 10 CFR 20.201
See the memorandum from J. E. Glenn to R. Cooper dated July 7, 1990.
This memo responds to a technical request from Region I, dated May 18, 1990, on the above subjects. In general, the staff may by 10 CFR 20.501 [or, at present, 10 CFR 20.2301] and 10 CFR 34.51 consider any application for an exemption to the regulations in 10 CFR Part 20 or 10 CFR Part 34 if it determines the exemption is (1) authorized by law, (2) will not result in undue hazard to life or property, and (3) the applicant has submitted sufficient justification. However, the staff is not required to grant an exemption request.
Provided below are answers to specific questions regarding posting and surveys when performing radiography on pipeline welds:
Posting of radiation areas per 10 CFR 34.42: Does NRC consider exceptions to the posting requirements in such practical field situations as thick brush or woods immediately adjacent to the radiography operation, or radiography operations that are adjacent to a heavily-travelled highway? Can dirt from the pipe ditch be used as a partial shield, or can the ditch itself be used as a barrier preventing access to the radiation area in lieu of posting?
The regulation clearly requires that areas in which radiography is being performed be conspicuously posted. That is, all potential pathways to radiation and high radiation areas must contain the appropriate posting. Exemptions have not been made for wooded or thick brush areas, ditches, or heavily travelled highways in the past. The convenience or inconvenience of the posting is not a sufficient criterion alone to grant an exemption.
Performance of radiation area surveys per 10 CFR 20.201 [or, at present, 10 CFR 20.1501]: How often does one need to survey to confirm the radiation and high radiation areas when performing radiography along a pipeline where weld exposure geometries are essentially the same but shielding provided by adjacent terrain varies?
The licensee is required to make an evaluation of radiation hazard any time the conditions of the radiation exposure changes. Accordingly, even though the weld-to-weld exposure geometries are essentially the same, if the shielding provided by adjacent terrain varies, a new survey / evaluation is required. Note that a measurement is not necessarily required in order to make an evaluation.
Regulatory references: 10 CFR 20.201, 10 CFR 20.501, 10 CFR 20.1501, 10 CFR 20.2301, 10 CFR 34.42, 10 CFR 34.51
Subject codes: 4.7, 7.1