2016:16 Technical Note, Possible influence from stray currents from high voltage DC power transmission on copper canisters

Main Review Phase

Introduction

As part of the Swedish Radiation Safety Authority’s (SSM) review of the Swedish Nuclear Fuel and Waste management company (SKB) license application for a final storage for spent nuclear fuel, SSM has asked for complementary information regarding the effect of stray currents from high voltage cables on copper corrosion (SSM 2012). SKB therefore has performed an extended study of the effects of high voltage DC power transmission as support for answering SSM. This study has been presented in the report SKB TR-14-15.

This report is a review of SKB report TR-14-15 and is the authors’ assessment in response to the following three questions raised by SSM together with relevant support analysis and technical material:

  1. If the voltage drop across the canister that are reported are accurate
  2. If the presented analysis adequately describes the current and future
    analysis cases
  3. The impact of telluric current on the voltage drop over the canister

The assessments made in this report are mainly based on the authors’ respective experience from previous work within electrical analysis, nuclear and HVDC. The authors’ combined university studies have also been used in parts of the review, mostly within the theoretical parts of the report.