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Canadian Coalition for Nuclear Responsibility’s  recommendations opposing the proposed30-year operating licence extension for the Darlington Nuclear Generating Station (DNGS)

27June 25, Gordon Edwards

Recommendation 1: CCNR urges the Commission to grant Darlington no more than a five-year licence, to incentivize the public to remain engaged on matters of radiological safety, and to pressure the staff of OPG and CNSC to improve their practices related to public heath and safety. In our opinion, under no circumstance should a licence of more than ten years be countenanced.

Comments: The CNSC is expected to review the financial guarantee for decommissioning the Darlington plant every five years. The plant’s safety analysis is expected to be reviewed every 10 years. Why should public input be so underappreciated that it only has to be considered once in three decades?

Suspicions of regulatory capture can only be intensified when regulatory staff meets with industry representatives behind closed doors, decade after decade, without any meaningful public involvement. After all, the CNSC’s primary legal obligations are to the Canadian public, the Canadian environment, and the international community – not to the licencee. Without reasonably frequent public hearings, without listening to the concerns of the public directly, staff may come to regard those legislated responsibilities as more abstract than real. The staff of the licensee and the staff of the regulator become of one mind; the public is seen as an unwelcome intruder.

Ultimately, this is not good for the CNSC or for OPG. CCNR believes it is also not good for the public, or for the trust that CNSC wishes to enjoy from the public.

Recommendation 2: CNSC staff should be required to report to the Commissioners and to the public on a regular basis what efforts are being made to drastically reduce the routine releases of radioactive materials into the environment from Darlington.

Comments: On an annual basis, Darlington releases several hundred trillions of becquerels of radioactive hydrogen (tritium). Tritium is readily incorporated into all living things in the form of radioactive water molecules, as a result of ingestion, inhalation, or absorption through the skin. Tritium emissions from Darlington are far greater than corresponding tritium emissions from any other power reactors in the world, except for other CANDU reactors. Although CNSC and OPG staff are both quick to point out that these tritium emissions are “within regulatory limits”, that does not exonerate CNSC from the responsibility of requiring that such emissions be kept “As Low As Reasonably Achievable”, in accordance with the ALARA principle. All radioactive emissions are ionizing. Ionizing radiation is acknowledged to be a Class 1 carcinogen. No genotoxic carcinogenic material should be disseminated freely into the environment without the strictest possible controls, regardless of whatever regulatory limits may have been established arbitrarily by fiat. There is no science-based rationale for Canada’s tritium standards. It is not honourable to allow such very large releases of radioactive hydrogen to continue unabated for another three decades without any discernible effort to drastically reduce those emissions. Indeed, what efforts have been made in the last 30 years or will be made in the next 30 years to cut these emissions by orders of magnitude? Is that even a goal of the Commission? Or is the operating licence for a nuclear power reactor also a licence to freely pollute ad infinitum?

Similar considerations apply to routine emissions of radioactive carbon-14 from Darlington, which are reported to be at least a trillion becquerels per year or more. Since carbon-14 has a radioactive half-life of 5,700 years, carbon-14 emissions accumulate in the environment year after year as each year’s emissions are simply added to the previous year’s emissions. Carbon-14 from DNGS has been accumulating already for over 30 years, and it will continue to accumulate for the next 30 years if the licence is granted as requested. Thus 1 trillion becquerels per year turns into 60 trillion becquerels overall. What, if anything, is CNSC or OPG doing to prevent this from continuing?

As long ago as 1980, the Select Committee on Ontario Hydro Affairs reported that trium and carbon-14 “are easily incorporated into human tissue. Carbon-14 is incorporated into the carbon that comprises about 18 percent of total body weight, including the fatty tissue, proteins and DNA [molecules]. Tritium is incorporated into all parts of the body…. Thus the radiological significance of both elements is not related to their inherent toxicity, as each is a very low energy form of radiation, but to their easy incorporation in the body.”

Recommendation 3: All radioactive releases from Darlington should be posted on-line in real time so the public can be properly notified of those releases as they happen.

Comments: Testimony before the Select Committee on Ontario Hydro Affairs in 1979 by Dr. Edward Radford (Professor of Environmental Epidemiology at the Graduate School of Public Health, University of Pittsburgh) indicated that sudden large pulses of tritium absorbed by a pregnant woman can have a life-long effect on her unborn daughter by causing genetic damage to the baby girl’s eggs – damage that will persist throughout her life and could affect her eventual offspring. In 2023, in just one week, 6,469 curies = 239 trillion becquerels of tritium were released from Darlington. That’s comparable to an entire year’s release of tritium from just one unit happening in just one week. Yet the public has no way of knowing about this sudden massive leak of tritium in order to do what they can to protect themselves and their unborn babies. For these reasons, OPG should be required by CNSC to publicly report all radioactive emissions on-line in real time, so that vulnerable citizens such as pregnant women and parents of young children can choose to vacate the area when sudden large releases of triium or other radionuclides occur.

Recommendation 4: In accordance with its mandate to disseminate objective scientific information, CNSC should publicly declare that it is not correct for anyone to say that nuclear energy is “clean” (or non-polluting).

Comments: In addition to the radioactive hydrogen and radioactive carbon released routinely in large amounts from Darlington, as well as the radioactive iodine, other routine emissions occur. Over 100 million becquerels of radioactive iodine vapour is released annually from Darlington, along with more than 10 million becquerels of radioactive particulates. In addition, millions of becquerels of alpha emitters are released every year from Darlington. Bear in mind that alpha-emitters are hundreds to thousands of times more biologically damaging, per becquerel, than beta-emitters or gamma-emitters. For example, elementary arithmetic shows that one becquerel of plutonium inside the body is about 18,000 times more biologically damaging than one becquerel of tritium at the same location. Tens of trillions of Bq-MeVs of radioactive noble gases are released, that are heavier than air and so stay close to the ground, delivering radioactuve exposures from abve by what is called “skyshine”. Does the Commission ever concern itself with  drastically reducing these large routine radioactive emissions? Does the Commission ever feel uneasy when nuclear power is called a “clean” or “non-emitting” energy source in defiance of scientific fact?

Recommendation 5: Darlington Nuclear Generating Station should not be given an operating licence for more than five years. At all future licencing hearings for Darlington, OPG’s detailed plans for dismantling the Darlington reactors should be spelled out in very specific terms and the public should be invited to weigh in on those plans from a community health and safety perspective.

Comments: During a retubing operation at Pickering many years ago, workers were contaminated with carbon-14 dust and carried that contamination into their homes for a period of several weeks. More recently, over 500 workers were contaminated with airborne plutonium dust for a period of several weeks during the refurbishment of Bruce unit 1. In both cases, the contamination was not detected by the standard radiation monitors in place at every nuclear power plant. In both cases, the radioactive contamination was only detected when air samples were analyzed and the offending materials were identified.

Dust that can contaminate the clothing or the lungs of workers, undetected, can equally well blow in the wind and contaminate people and property far from the reactor site. The public should be fully informed of the precise details of OPG’s plans for radioactive demolition, and given a chance to have their own input into those plans. It is possible, indeed likely, that a detailed examination of those plans will lead to the need for a greatly enhanced financial guarantee on the part of OPG to ensure that those plans can be carried out safely and to the complete satisfaction of local residents. It is also important that ratepayers learn the true cost of nuclear decommissioning, which will give a more realistic assessment of the total cost of nuclear-generated electricity.

Recommendation 6: CNSC staff be instructed by the Commission members to commission experts not affiliated with CANDU reactor design, operation, or regulation, to conduct an independent peer review of the calculations that led CNSC staff to conclude that 100 trillion becquerels of cesium-137 is a realistic and acceptable estimate of the “source term” following a severe nuclear accident at Darlington Nuclear Generating Station.

Comments: CCNR has obtained documentary evidence that this number was arbitrarily chosen by CNSC staff without any credible accident scenario to support that number. CCNR analysts have also examined the 2015 CNSC document Study of Consequences of a Hypothetical Severe Nuclear Accident and Effectiveness of Mitigation Measures. In paragraph one of section 3.1, the authors of the report state that a “large release” of radioactivity is, by definition, any release of more than 100 terabecquerels of cesium-137. Anything less than 100 TBq does not even qualify as a large release. Then, in the second paragraph of section 3.1, the authors arbitrarily select that very number, the lowest possible number, namely 100 terabecquerels, as their assumed large release from Darlington. In doing so staff ignores its own definition, that all large releases must be greater than that amount. Please note that the authors of the CNSC report have simply chosen the lowest possible number that can be used to describe a large radioactive release, and they have used that number as an estimate of what a large release at Darlington might actually be. Despite promising to do so, the authors fail to describe or refer to any realistic accident scenario that would in fact result in such a small radioactive release of cesium-137.

Using straightforward calculations, CCNR estimates that a typical Darlington core contains a total of at least 55,000 trillion becquerels of cesium-137. Since there are 480 fuel channels in each Darlington reactor, each channel contains about 114.6 trillion becquerels of cesium-137. At a temperature of 1500 degrees C (well below the melting point of the fuel) the exposed fuel will release about 25% of the cesium inventory in one hour. In the event of severe core damage, all of the cesium released from the overheated fuel will escape from the calandria because the rupture disks on top will have exploded, providing an unfiltered pathway for the cesium vapour to escape into the containment. Given the fact that each of the 480 fuel channels can release 57 trillion becquerels of cesium-137 in one hour, it is impossible to believe that only 100 trillion becquerels of cesium-137 will find its way out into the environment, given the relatively leaky containment system that exists at Darlington.

Recommendation 7: OPG should not be given an operating licence for a period of more than five years, and all future licencing hearings for Darlington should include a detailed re-evaluation of Emergency Measures in accordance with a more realistic estimated source term.

Comments: In the event of a severe accident in a CANDU reactor, leading to a truly large release of radioactivity, emergency measures that are currently predicated on a maximum release of 100 trillion becquerels of cesium-137 will be woefully inadequate. Radioactive cesium contamination of homes and properties will be far greater, more extensive, and persistent, than currently considered possible. Residential and commercial areas closest to the Darlington plant may well remain uninhabitable for decades, as we learned from bitter experiuence at Chernobyl and Fukushima Daiichi. Considering the enormous volume of radioactively contaminated water that was flushed into the Pacific Ocean following the Fukushima accident, including the 1.2 million tons of radioactive water that is currently being dumped into the Pacific, one can only wonder about the deleterious effects on Lake Ontario and the millions of people that draw their drinking water from the Lake. Canadians deserve an honest, science-based, realistic assessment of what the consequences of a severe nuclear accident might be in Canada. The CNSC has an obligation to provide them with objective scientifically based information, not self-serving efforts to low-ball the risk estimates for public relations purposes. The public will have to be consuilted more frequently rather than less frequently. Their right to a healthy body and a healthy environment cannot be taken for granted for thirty yeards at a time. Shame on OPG for even suggesting such a thing.

One final word. CCNR fully supports the position of Dr. Frank Greening against wasting valuable hearing time by allowing private profit-making parties or other project-supporting groups to have equal time with public or indigenous intervenors who are addressing legitimate matters of public health and safety or environmental integrity that are fundamental to the core mission of CNSC as a regulator. The time saved by eliminating such promotional testimony can be used to extend the time available for other presenters to make their interventions, or to provide closing argumants near the end of the proceedings as would be permitted in a judicial setting.

June 30, 2025 - Posted by Christina Macpherson | Canada, safety