March 23, 2011
AECL ordered to
review safety
Atomic Energy of Canada Ltd has
been ordered to review the safety of the Chalk River labs in light of
the devastating earthquake that hit Japan this month.
The Canadian Nuclear Safety Commission (CNSC) issued orders to all of
its major licence holders - including AECL, Ontario Power Generation,
New Brunswick Power and Bruce Power - to prepare a review by April 29.
The orders were issued last Thursday by Ramzi Jammal, chief regulatory
operations officer for the CNSC.
In a letter to Hank Drumhiller, vice-president and chief nuclear
officer for AECL, Jammal says the review must look at the initial
“lessons learned” from the earthquake in Japan and re-examine the
“safety cases” for Canada's nuclear facilities, “in particular the
underlying defence in depth concept.”
The review should focus on threats from “external hazards such as
seismic, flooding, fire and extreme weather events,” the licence
holders' plans for “prevention and mitigation of severe accidents” and
their overall emergency preparedness.
The review must also report on plans for “short-term and long-term
measures to address any significant gaps.”
AECL and the other licence holders have until April 1 to reply to
Jammal, either confirming that they will meet the April 29 deadline, or
explaining “any reasons why the request or any part of it will not be
carried out” and proposing any alternatives “to achieve the objectives
of the request.”
The potential threat of a major earthquake, however unlikely, was the
catalyst behind the first major “isotope crisis” when the NRU reactor
was shut down in late 2007.
AECL agreed at the time to place NRU in an “extended shutdown” after
staff of the CNSC said that the installation of a seismically
qualified, backup emergency power system (EPS) on two main cooling
pumps was one of seven safety upgrades to the reactor that were
supposed to be completed as part of the company’s new licence in 2006.
But the shutdown made headline news after it became clear that the
shutdown would dry up the world’s supply of medical isotopes used to
detect and treat cancers, heart disease and other conditions.
Chalk River was at the time producing more than 60 per cent of the
world’s supply of those isotopes.
The federal government stepped in on December 12, bringing in emergency
legislation allowing AECL to operate NRU for 120 days without the
approval of the safety commission, as long as the company was
“satisfied that it is safe to do so.”
The reactor was restarted after the EPS was connected to the first of
the two pumps. The second was completed that January.
NRU actually has eight cooling pumps, which get their power from the
regular electricity grid.
However, four of the pumps also have a double backup power system
provided by diesel generators and DC battery motors.
The EPS upgrade was designed to ensure that two of NRU’s pumps would
still have power in the case of a severe earthquake.
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