(April 23, 1993) Greenpeace issued an urgent call for a phase-out of Ontario's nuclear power plants, on the grounds that a design flaw could lead to a meltdown.
(390.3799) WISE Amsterdam - The Greenpeace report, Safety Risks from Damaged Pressure Tubes, surveys inspection reports on Ontario's reactors by government and the Atomic Energy Control Board (AECB), the federal agency charged with regulating nuclear power plants.
In an article in the Globe and Mail (17 Febr. 1993), AECB officials acknowledge the design flaws in the province's CANDU reactors.
Among the findings in the Greenpeace report:
- The tubes which contain the reactors' nuclear fuel are developing problems known as 'fretting'; Fretting can lead to ruptures or, in the worst case, sudden bursting of the tubes; It is possible that a sudden rupture could also disable the emergency shutdown systems; Multiple bursts could also lead to a serious accident;
- The AECB is unsatisfied with Ontario Hydro's ability to detect leaks in the tubes quickly enough to prevent a major catastrophe;
- The AECB now believe that a pressure tube accident could have far more catastrophic consequences than first believed;
- The AECB has already ordered the shut-down of some nuclear reactors due to problems with pressure tubing fretting, a precaution which indicates the scope of the danger to the public. However, the agency has also allowed the reactors to be restarted in damaged state.
"Ontario Hydro is operating a game of Russian Roulette with their reactors - a game we could all lose", said Stan Gray, Greenpeace's nuclear campaigner. "We are demanding that Ontario begin to phase-out nuclear power immediately, starting with the reactors with the most serious fretting".
Another CANDU design flaw was exposed in the beginning of March. Ontario Hydro admitted that it could not prevent a meltdown at it's Bruce plant in the event of a loss of coolant accident. Accordingly, it had to reduce the stati-on's power to 60% - effectively, shutting down 105 of Ontari-o's entire electric generating capacity. This event was the first effective admission by the industry that its reactors were vulnerable to a Chernobyl-type accident. The public, however, was not informed of this by Hydro. Rather, the utilities downplayed the event and only put out misleading press that implied the cutback was temporary - caused by a computer hang-up or unspecified technical difficulties. There was no hint that the reactors were found to be in violation of their licensing safety standards, and that this posed a risk.
Both these design problems present the risk of major nuclear accidents: both would require extensive engineering and re-building of the nuclear core if the stations are to be rebuilt to safety standards. This is next to impossible and a waste of effort and money even if it was theoretically possible.
In his recent restructuring plan, Hydro Chair Maurice Strong deferred a decision on the $ 3.3 billion refurbishing of the Bruce A station. Disappointingly, he said that Hydro might operate the reactors until their time ran out or the AECB decided to shut them down for safety reasons. Strong also said he might do the refurbishing if circumstances warranted in the future.
Sources:
- Greenpeace Canada Press-release, 17 Febr. 1993
- Globe and Mail (Can.), 17 Febr. 1993
- The Ottawa Citizen 14 March 1993
- and personal letter Stan Gray
Contact: Stan Gray or Andrea Ritchie at Greenpeace, 185 Spadina Avenue, Toronto Canada M5T 2C5
Tel: + 416 3458408. Fax: + 416 3458422