CHALK RIVER, ON, June 10 /CNW/ - Atomic Energy of Canada Limited (AECL)
provides the following status report on the unplanned shutdown of the NRU
reactor at its Chalk River Laboratories.
AECL reports that the ongoing process to remove fuel from the NRU reactor
is continuing, with 63 of the fuel rods removed as of June 9th. There were
approximately 100 rods in the reactor at the time NRU was shut down on May
14th. Of this total, 81 were used for fuel and the remaining used for isotope
production and reactor control.
Completion of rod removal and the subsequent removal of heavy water from
the reactor is projected to be complete by the end of this month.
Measures have been taken to reduce the leak rate with the addition of a
solution to temporarily plug the leak site. Results of this action will take
time to become evident. The leak rate remains steady at about 4kg/hr. A small
portion of the leakage evaporates and results in a monitored airborne tritium
release through the NRU reactor ventilation system. While this airborne
tritium release remains about 1/1,000 of the regulatory limit, the action
level for tritium release to the atmosphere was exceeded this week due to the
Preparation for vessel inspection continues. Special examination
equipment to perform this function has been commissioned. A scan on the inside
wall of the reactor vessel, at a location adjacent to the leak site, was
successfully completed using ultrasonic and eddy current probes. Analysis of
the data will require several days to complete.
A team of industry specialists has recently conducted a workshop to
review cleaning, inspection and repair technologies for the reactor vessel.
AECL will draw on advice provided by this group to determine the best approach
to proceed with vessel repairs.
Hugh MacDiarmid, President and CEO of AECL stated "We view the production
of medical isotopes as part of our core mission, for Canada, and indeed for
the world. As such, we have a duty to resume production as soon as it is safe
and practical to do so. AECL staff have been working around the clock to
complete the investigations and we will draw on all available expertise, both
internal and external, so that we apply the best minds to resolve this issue."
Further guidance on a return to service date will be provided once a
final decision has been made with respect to the repair technique chosen. AECL
continues to communicate closely with CNSC on NRU outage issues, and CNSC
safety inspectors at Chalk River are monitoring all NRU work.
AECL confirms that there is no threat to workers, the public, the
environment or nuclear safety related to this event. AECL will continue to
provide updates to the CNSC and stakeholders when new information becomes
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For further information:
For further information: Dale Coffin, Director, Corporate Communications
AECL, 1-866-886-(AECL) 2325