The Ionising Radiations Regulations 2017

Estimated and notional doses and special entries

23.—(1) Where a dosemeter or other device is used to make any individual measurement under regulation 22(2) and that dosemeter or device is lost, damaged or destroyed or it is not practicable to assess the dose received by a classified person over any period, the employer must—

(a) make an adequate investigation of the circumstances of the case with a view to estimating the dose received by that person during that period and either—

(i) in a case where there is adequate information to estimate the dose received by that person, send to the approved dosimetry service an adequate summary of the information used to estimate that dose and arrange for the approved dosimetry service to enter the estimated dose in the dose record of that person; or

(ii) in a case where there is inadequate information to estimate the dose received by the classified person, arrange for the approved dosimetry service to enter a notional dose in the dose record of that person which must be the proportion of the total annual dose limit for the relevant period; and

(b) in either case referred to in sub-paragraph (a), take reasonable steps to inform the classified person of the entry in their dose record and arrange for the approved dosimetry service to identify that entry as an estimated dose or a notional dose as the case may be.

(2) The employer must, at the request of the classified person (or a person formerly employed by that employer as a classified person) to whom the investigation made under paragraph (1) relates and on reasonable notice being given, make available to that person a copy of the summary sent to the approved dosimetry service under paragraph (1)(a).

(3) Subject to paragraphs (5) and (8), where an employer has reasonable cause to believe that the dose received by a classified person is much greater or much less than that shown in the relevant entry of the dose record, the employer must make an adequate investigation of the circumstances of the exposure of that person to ionising radiation and, if that investigation confirms the employer’s belief, the employer must, where there is adequate information to estimate the dose received by the classified person—

(a) send to the approved dosimetry service an adequate summary of the information used to estimate that dose;

(b) arrange for the approved dosimetry service to enter that estimated dose in the dose record of that person and for the approved dosimetry service to identify the estimated dose in the dose record as a special entry; and

(c) notify the classified person accordingly.

(4) The employer must make a report of any investigation carried out under paragraph (3) and must preserve a copy of that report for a period of 2 years from the date it was made.

(5) Paragraph (3) does not apply—

(a) in respect of a classified person subject only to an annual dose limit, more than 12 months after the original entry was made in the record; and

(b) in any other case, more than 5 years after the original entry was made in the record.

(6) Where a classified person is aggrieved by a decision to replace a recorded dose by an estimated dose pursuant to paragraph (3) that person may, by an application in writing to the appropriate authority made within 3 months of the date on which that person was notified of the decision, apply for that decision to be reviewed.

(7) Where the appropriate authority concludes (whether as a result of a review carried out pursuant to paragraph (6) or otherwise) that—

(a) there is reasonable cause to believe the investigation carried out pursuant to paragraph (3) was inadequate; or

(b) a reasonable estimated dose has not been established,

the employer must, if so directed by the appropriate authority, require the approved dosimetry service to re-instate the original entry in the dose record.

(8) The employer must not, without the consent of the appropriate authority, require the approved dosimetry service to enter an estimated dose in the dose record in any case where—

(a) the cumulative recorded effective dose is 20 mSv or more in one calendar year; or

(b) the cumulative recorded equivalent dose for the calendar year exceeds a relevant dose limit.

(9) In this regulation “appropriate authority” means—

(a) in relation to a classified person employed wholly or mainly on nuclear premises, the ONR;

(b) otherwise, the Executive.