November 25, 1999
Introduction and summary:
Energy Probe is the oldest project of Energy Probe Research Foundation, one of Canada’s largest environmental organizations, with over 20,000 supporters. Energy Probe has long been involved in nuclear matters and in the affairs of the Atomic Energy Control Board, including numerous written submissions and several appearances before the Board.
Energy Probe shares many, if not all, of the concerns that have been expressed to the Board by concerned citizens of Port Hope. We will restrict our comments in this submission to the following basic and simple point:
The operation of Cameco’s facility subjects people in Port Hope to radiation exposures, and health risks, that are unacceptable.
Since it is AECB’s job to protect these residents from unacceptable exposures and risks, Energy Probe urges the AECB to do so, by significantly reducing these exposures and risks. In addition, the long-term existence of these unacceptable exposures and risks, in our view, strengthens a number of the claims of Port Hope residents — e.g., to a community health study of their choosing, and to proper remediation of the town’s “historic” or “orphaned” radioactive wastes.
The radiation exposures:
According to AECB staff, in BMD 99-123, 1999-09-21, “Cameco Corporation – Port Hope – Renewal of Fuel Facility Operating Licence AECB-FFOL-225-4”, section 3.1.1:
It is estimated that effects of external radiation and uranium emissions from Site 1 contributed a maximum calculated dose of 0.19 mSv/y to the most exposed member of the public during 1998 (This is equivalent to 38 % of the licensed dose limit; 0.5 mSv/y).
At Site 2, the external gamma measurements taken at the fenceline locations opposite the critical receptors averaged 21.5 µR/h. This value may be compared with the limit prescribed in the licence of 40 µR/h.
Of course, if public exposures were being kept below levels that are “safe”, it would makes sense to renew the license and continue with the status quo. But these licensed dose limits should not be mistaken for “safe” exposure levels. Nor, in our opinion, are they acceptable.
The health risks posed by radiation exposures:
According to the latest report from the International Commission on Radiological Protection (ICRP, the international agency which guides AECB’s radiation-protection regulations), known as “ICRP-60”, the nominal risk coefficient of low-level radiation exposure for one health end-point (fatal cancer) to a general population of mixed ages and gender is 5 excess fatal cancers to a population of 100 exposed to 1 Sv — a risk often abbreviated as “5% per Sv” or “5% per person-Sv”. When the ICRP adds in highly discounted estimates of the risk of non-fatal cancer and hereditable effect, it arrives at an estimate of “health detriment” of approximately 7.2% per person-Sv.
There are excellent reasons to believe that the actual health risks of radiation exposure are greater than ICRP’s risk coefficients, including the following:
ICRP’s historical record of underestimating cancer risks: The ICRP’s estimate of the risk of fatal cancer from exposing a population to low-level radiation has increased roughly 50-fold since 1934, prompting the ICRP to drop its exposure limits almost as far. It would seem imprudent to assume that this robust historical trend has stopped, or reversed.
As ICRP itself acknowledges, the human data, largely at higher exposures, actually display a risk coefficient twice as high — 10% fatal cancer per person-Sievert, not 5% — but the ICRP has assumed the existence of a Dose Rate Effectiveness Factor (DREF) of 2, which supposedly halves the effectiveness of radiation at lower doses. That “fudge-factor” is not supported by the human cancer tumour mortality data, which in ICRP-60’s words, “fit a linear response with dose quite well over a broad dose range”. Indeed, ICRP-60 (1991) concedes that their preferred value of 2 is about as high as the data can possibly justify! If DREF is wrong and true linearity is correct (i.e., DREF = 1), then the actual risks of low-level radiation exposure are twice as high as ICRP’s coefficients suggest.
Nine years has passed since the ICRP reached a consensus that low-level exposures to radiation are approximately five times more cancer-causing than previously estimated — and that maximum dose limits should accordingly be lowered by a factor of five. As the millennium closes, Canada — led by AECB — is apparently unique among advanced countries in still not having tightened radiation exposure standards! But a glacially slow pace of modernizing standards does not make unacceptable exposures and risks acceptable; it just makes them legal, more is the pity.
Furthermore, the license limits, “control equation” and actual exposures in Port Hope have not been lowered five-fold, despite the widespread acceptance of the new scientific consensus. In other words, we now estimate that the AECB-licensed operation of Cameco is today causing greater health risks in Port Hope than the estimates that were given to the public and civic officials in the past by both the licensee and the regulator.
We note with concern that AECB’s BMDs still generally make reference only to the old, obsolete regulatory limits. We believe that neither the people of Port Hope nor the AECB’s Board Members should have exposures “put into perspective” by comparison with radiation exposure standards that bear no relationship to “safe” or “acceptable” levels of exposure. During the remaining months before the new standards come into legal force, we urge AECB Board and staff to behave as if ICRP-60 was published nine years ago.
The health risk calculations for Port Hope:
Applying ICRP’s risk coefficients to the estimated exposures reported by AECB staff in BMD 99-123 yields the following calculations of lifetime health risks:
1. For the public exposed to a total Cameco-source radiation dose of 0.19 mSv/y from Site 1:
Fatal cancer risk only: 0.19 mSv/y x 76 y/avg. life x 0.05 fatal cancers/Sv = 7.22 x 10-4 or 722 excess fatal cancers per million people so exposed.
“Serious health effects” or what ICRP calls “total health detriment”: 0.19 mSv/y x 76 y/avg. life x 0.072 “serious health effects”/Sv = 1.04 x 10-3 or 1040 excess “serious health effects” per million people so exposed.
2. For the public exposed to an external gamma dose from Cameco’s Site 2 that averaged 21.5 µR/h, we must make assumptions about (1) the fraction of the measured gamma radiation that penetrates their house to the inhabitants, and (2) the fraction of time that they are in their house. In the absence of quantitative evidence, I will assume prudently (“conservatively”) that both fractions are 100%, aware that the results may consequently be overstated by some factor. (The equivalency of 1 R to 0.01Sv is a reasonable approximation, varying slightly, we understand, with the nature of the gamma radiation.)
Fatal cancer risk only:
21.5 µR/h x 0.01Sv/R x 8760h/y x 76 y/avg. life x 0.05 fatal cancers/Sv = 7.16 x 10-3 or 7160 excess fatal cancers per million people so exposed.
“Serious health effects” or what ICRP calls “total health detriment”
21.5 µR/h x 0.01Sv/R x 8760h/y x 76 y/avg. lifex 0.072 “serious health effects”/Sv = 1.03 x 10-2 or 10,300 excess “serious health effects” per million people so exposed.
Are these risks “acceptable”? To whom?
In the regulation of exposures to non-radioactive carcinogens — cancer-causing agents that don’t make a geiger counter click — these high risk levels to innocent members of the public would never be tolerated. Put in different words, we do not believe there is another public-health regulator in Canada except the AECB that would tolerate these public risk levels. Indeed, significant cleanup efforts and expenditures (public and private) have already been made in Canada to lower much more modest public risks (some of them to small or rural populations), down to lifetime risk levels close to (and sometimes lower than) one “serious health effect” per million people!
In fact, it was precisely this enormous “double standard” that led the Ministers of Health and Natural Resources to convene a review group to examine the “dichotomies and discrepancies” between the various definitions of acceptable risk. As Board Members may or may not know, after eighteen drafts of their report had circulated among the guardians of the status quo, the members of that review group (“JWG-6”) made a conscious decision to ignore their terms of reference completely. As a result, those “dichotomies and discrepancies” persist in full force, and the people of Port Hope are exposed to health risks from Cameco’s activities that would not be tolerated by other regulators, or if they came from non-radioactive substances.
Indeed, these risks would not even be tolerated by AECB if they came from a nuclear generating station! “Action levels”, “target levels” and “ALARA levels” around Canada’s nuclear generating stations — as well as actual estimated public radiation exposure levels — are all significantly lower than these actual estimated exposure levels from Port Hope. In other words, even AECB’s own alarm bells would ring if the neighbours near one of Canada’s nuclear generating stations were exposed to the radiation doses now being received by the equally innocent and deserving neighbours of Cameco.
We would urge AECB to re-examine these exposures and these estimated risks. Perhaps some regulatory staff should be seconded between AECB’s branches, or between AECB and other regulators. Whatever the mechanism, AECB must ensure that these risks in Port Hope are reduced to levels that AECB Board members might accept for their own families. Surely the residents at risk in Port Hope — AECB’s “clients” — deserve no less from their regulator