Comments on the ICRP Draft Document:
Operational Quantities for External Radiation Exposure
On behalf of the World Nuclear Association
We appreciate the attempt made to simplify the system, and can understand the confusion that has resulted from the current system. The proposals in the report, however, are new and there has been limited opportunity to discuss the recommendations. With this in mind, below are a series of general comments:
1) Although scientifically more accurate with the revised quantities reducing uncertainties in dose estimates, there are measurement errors that are much more significant. The difference in values between the current conversion coefficients and proposed conversion coefficients are small. Is there sufficient justification provided to make this change?
2) If implemented, the changes will affect users from multiple sectors. Although there has been insufficient time to gather data, if the recommendations are implemented, the cost could be in the millions (ballpark figure). Below is one case study for a nuclear power plant consisting of three reactors:
There will be some challenges with how the calibration of dose rate instruments is going to be executed. The software of the instruments has to be changed to evaluate the ambient dose, H* which can either be done through new instrumentation or reprogramming existing instrumentation (both options are costly). The correction with the conversion coefficients is very small compared to the total errors of an actual measurement in a nuclear plant with its inhomogeneous field and directional dependence. The cost for changing the dose rate instruments at our plant is estimated to be 1 million euros.
We do not believe that a cost-benefit analysis has been done, and would advocate such considerations to be incorporated into the report.
3) The report presents the advantages of the revised quantities but does not convey the limitations. It could be useful to have a table showing the pros/cons with existing versus proposed approach.
4) The report is technical in nature, and it is not easy for the end-user to understand the main thrust of the report. The content is not easily digestible by end-users who are not necessarily dosimetry experts; it would be useful if there were a summary for non-experts. Furthermore, there is a need for a thorough editorial review as there is a need to check the flow, consistency, punctuation and grammar throughout.
5) If the change is not implemented globally, there could be further fragmentation in the system of protection. Will there be an issue of comparing apples and pears when looking at an international picture?