Request pursuant to Subsection 12(2) of the General Nuclear Safety and Control Regulations: Potential Neutron Exposure of Workers

Directorate of Power Reactor Regulation

13 June 2024

Mr. Steven Bagshaw
Site Vice President
Point Lepreau Nuclear Generating Station
New Brunswick Power
P.O. Box 600
Lepreau, NB E5J 2S6

Dear Mr. Bagshaw:

This letter is a request pursuant to subsection 12(2) of the General Nuclear Safety and Control Regulations.

Following the recent discovery of neutron radiation from refurbishment waste containers at Waste Facilities at the Canadian NPP sites, it was determined that some unaccounted worker exposure due to neutron radiation associated with the refurbishment waste containers may have occurred. The contents of the containers include irradiated reactor components, such as pressure tubes, calandria tubes, or calandria tube inserts, removed from reactors during refurbishments.

I request, pursuant to my authority as a person authorized by the Commission for the purposes of subsection 12(2) of the General Nuclear Safety and Control Regulations that New Brunswick Power Corporation (NB Power) conduct and submit to the CNSC an analysis, by no later than July 15th, 2024, which includes the following items:

• Results of neutron assessments carried out at the Point Lepreau Nuclear Generating Station (PLNGS);
• And, if applicable to PLNGS:
  • A summary of the work activities with the most potential for unaccounted dose and an associated conservative estimate of the magnitude of that dose;
  • Assessment of whether the unaccounted dose has caused any worker to exceed the effective dose limit for the current one-year dosimetry period, as well as the current and previous five-year dosimetry periods;
  • Methods, models and modeling assumptions used to ascertain worker neutron doses;
  • A characterization of the neutron source term;
  • An explanation of whether NB Power included a neutron source term in their original source term characterization of reactor component waste;
  • Additional work controls implemented to mitigate future exposures; and
  • Confirmation that affected parties have been informed.

Please note that in accordance with subsection 12(2) of the General Nuclear Safety and Control Regulations, NB Power is also required to file a report by June 24, 2024, with the Commission that contains the following information:

1. confirmation that the request will or will not be carried out or will be carried out in part;
2. any action that NB Power has taken to carry out the request or any part of it;
3. any reasons why the request or any part of it will not be carried out;
4. any proposed alternative means to achieve the objectives of the request; and
5. any proposed alternative period within which NB Power proposes to carry out the request.

If you have any questions, please do not hesitate to contact Director, Point Lepreau Regulatory Program Division, Heather Davis at heather.davis@cnsc-ccsn.gc.ca

Sincerely,

Alex Viktorov
Director General
Directorate of Power Reactor Regulation

c.c.: J. Nouwens, N. Reicker (NB Power)

D. Beaton, A. Baig, A. Bulkan, K. Campbell, H. Davis, K. Owen-Whitred, C. Purvis, R. Richardson, L. Sigouin, B. Torrie (CNSC)