Isotope producer is to restart amid controversy

In an extraordinary sequence of events the Canadian parliament has overruled the Canadian Nuclear Safety Commission (CNSC) and ordered the early restart of the NRU reactor, which provides muchof the world's medical isotope supply.

The Canadian lower house passed an after-hours bill on 11 December authorising the early restart of NRU at Chalk River, before owner-operator Atomic Energy of Canada Limited (AECL) and the CNSC had completed safety reviews of an interim operation plan.

AECL has "initiated procedures to restart" the reactor, and said it should begin producing medical isotopes again around 20 December.

An isotope supply crisis began on 6 December when a scheduled shutdown of the NRU facility at Chalk River was extended by AECL. The crown corporation voluntarily made the move after the CNSC found that safety upgrades it had mandated in mid-2006 had not been completed.

Key among the upgrades were two new backup cooling pump motor starters deemed necessary to ensure the continued forced circulation of cooling water, should pumps in normal use fail for any reason. In addition, upgraded back-up diesel generators were required to ensure supply of power to those pumps in case grid connection also failed simultaneously. Not carrying out the work put AECL in breach of its nuclear operating license.

To complete the work would have taken AECL some weeks, during which time supplies of medical isotopes molybdenum-99 and technetium-99m would have been exhausted, delaying treatment and putting lives at risk.

In a letter to Gary Lunn, minister of natural resources, and Tony Clement, minister of health, AECL's Ken Petrunik wrote that "heroic efforts" from AECL and its suppliers had enabled the company to upgrade one of the back-up pumps and the back-up power supply by 11 December.

Petrunik wrote: "AECL assures the government of Canada that NRU is safe to start up and operate in this mode."

However, to make necessary changes to the other pump would take until 20 December and, in the light of a growing shortage of medical isotopes, AECL was working with CNSC to gain approval to operate in this interim configuration - which remained outside its licence - and carry out the remaining upgrade over 16 weeks.

But the CNSC stuck to its guns. The independent body's President, Linda Keen, said to parliament: "In order for operations to resume, the CNSC must be satisfied that AECL has met all of its regulatory requirements and licence conditions, and that the reactor can operate safely. This is required by the Nuclear Safety and Control Act."

When a motion was tabled on 11 December to allow operation despite the CNSC, questions to Conservative prime minister Stephen Harper saw the issue become a political football. Liberal Michael Ignatief asked why the CNSC had no role in assessing NRU was safe during the 120-day period of the restart bill, to which Harper replied, "The continuing actions of the Liberal-appointed CNSC will jeopardise the health and safety and lives of tens of thousands of Canadians."

Harper later added: "It is in the public interest to get this reactor back online and get these medical radioisotopes produced. There is no threat to nuclear safety at all. There is a threat to human life."

On 13 December AECL announced it was beginning operations to restart the reactor, saying the unit was "safer than it has ever been."