OAR 333-120-0240
Control of Exposure from External Sources in Restricted Areas: Control of Access to Very High Radiation Areas — Irradiators
(1)
Each area in which there may exist radiation levels in excess of five gray (500 rad) in one hour at one meter from a sealed radioactive source that is used to irradiate materials must meet the following requirements.(a)
Each entrance or access point must be equipped with entry control devices which:(A)
Function automatically to prevent any individual from inadvertently entering the area when very high radiation levels exist; and(B)
Permit deliberate entry into the area only after a control device is actuated that causes the radiation level within the area, from the sealed source, to be reduced below that at which it would be possible for an individual to receive a deep-dose equivalent in excess of one mSv (0.1 rem) in one hour; and(C)
Prevent operation of the source if the source would produce radiation levels in the area that could result in a deep-dose equivalent to an individual in excess of one mSv (0.1 rem) in one hour.(b)
Additional control devices must be provided so that, upon failure of the entry control devices to function as required by subsection (1)(a) of this rule:(A)
The radiation level within the area, from the sealed source, or radiation source is reduced below that at which it would be possible for an individual to receive a deep-dose equivalent in excess of one mSv (0.1 rem) in one hour; and(B)
Conspicuous visible and audible alarm signals are generated to make an individual attempting to enter the area aware of the hazard and at least one other authorized individual, who is physically present, familiar with the activity, and prepared to render or summon assistance, aware of the failure of the entry control devices.(c)
The licensee or registrant must provide control devices so that, upon failure or removal of physical radiation barriers other than the radiation source’s shield or shielded storage container:(A)
The radiation level from the radiation source is reduced below that at which it would be possible for an individual to receive a deep-dose equivalent in excess of one mSv (0.1 rem) in one hour; and(B)
Conspicuous visible and audible alarm signals are generated to make potentially affected individuals aware of the hazard and the licensee/registrant or at least one other individual, who is familiar with the activity and prepared to render or summon assistance, aware of the failure or removal of the physical barrier.(d)
When the shield for the stored source is a liquid, the licensee or registrant must provide means to monitor the integrity of the shield and to signal, automatically, loss of adequate shielding.(e)
Physical radiation barriers that comprise permanent structural components, such as walls, that have no credible probability of failure or removal in ordinary circumstances need not meet the requirements of subsections (1)(c) and (d) of this rule.(f)
Each area must be equipped with devices that will automatically generate conspicuous visible and audible alarm signals to alert personnel in the area before the source can be put into operation and in sufficient time for any individual in the area to operate a clearly identified control device, which must be installed in the area and which can prevent the source from being put into operation.(g)
Each area must be controlled by use of such administrative procedures and such devices as are necessary to ensure that the area is cleared of personnel prior to each use of the radiation source.(h)
Each area must be checked by a radiation measurement to ensure that, prior to the first individual’s entry into the area after any use of the source, the radiation level from the source in the area is below that at which it would be possible for an individual to receive a deep-dose equivalent in excess of one mSv (0.1 rem) in one hour.(i)
The entry control devices required in subsection (1)(a) of this rule must have been tested for proper functioning. Records of required testing must be maintained in accordance with OAR 333-120-0680 (Records of Testing Entry Control Devices for Very High Radiation Areas).(A)
Testing must be conducted prior to initial operation with the source of radiation on any day (unless operations were continued uninterrupted from the previous day); and(B)
Testing must be conducted prior to resumption of operation of the source of radiation after any unintended interruption; and(C)
The licensee or registrant must submit and adhere to a schedule for periodic tests of the entry control and warning systems.(j)
The licensee or registrant may not conduct operations, other than those necessary to place the source in safe condition or to affect repairs on controls, unless control devices are functioning properly.(k)
Entry and exit portals that are used in transporting materials to and from the irradiation area, and that are not intended for use by individuals, must be controlled by such devices and administrative procedures as are necessary to physically protect and warn against inadvertent entry by any individual through these portals. Exit portals for processed materials must be equipped to detect and signal the presence of any loose radiation sources that are carried toward such an exit and to automatically prevent loose radiation sources from being carried out of the area.(2)
Persons holding licenses or registrations or applicants for licenses or registrations for radiation sources that are within the purview of section (1) of this rule and that will be used in a variety of positions or in locations, such as open fields or forests, that make it impracticable to comply with certain requirements of section (1) of this rule, such as those for the automatic control of radiation levels, may apply to the Authority for approval of the use of alternative safety measures. Any alternative safety measures must provide a degree of personnel protection at least equivalent to those specified in section (1) of this rule. At least one of the alternative measures must include an entry-preventing interlock control based on a measurement of the radiation that ensures the absence of high radiation levels before an individual can gain access to the area where such radiation sources are used.(3)
The entry control devices required by sections (1) and (2) of this rule must be established in such a way that no individual will be prevented from leaving the area.
Source:
Rule 333-120-0240 — Control of Exposure from External Sources in Restricted Areas: Control of Access to Very High Radiation Areas — Irradiators, https://secure.sos.state.or.us/oard/view.action?ruleNumber=333-120-0240.