NUCLEAR ACCIDENTS: BOTHERED, BEWITCHED OR BEWILDERED?

A host of nuclear accidents [1] across Europe this summer, including 100 workers inadvertently contaminated and an off-site release of radioactive iodine, served as reminders that far from being clean, the industry is a source of routine and accidental radioactive pollution [2]. Operators and regulators were prompt to assure that public health was unharmed. Yet, when Anne Lauvergeon, CEO of AREVA came to visit SOCATRI, the subsidiary guilty of dumping uranium by error in local waterways, she was met by public outcry.

AREVA, the world’s largest nuclear group, was responsible for three of the events – six of which occurred in France, the most nuclear-dependent country with 80% of nuclear-produced electricity. Four of the French events concerned the 600 hectare Tricastin site.

Responding to critics on the 75 Kg uranium spill, Lauvergeon, said that nuclear installations are subject to “the most draconian international norms” and deplored public “confusion” about the “incident”. [3]

That nuclear power is a source of confusion is undeniable but comments such as Lauvergeon’s do nothing to dissipate it. For example, there are no binding international radioprotection standards. National regulators follow the ill-defined ALARA – As Low As Reasonably Achievable – guidelines allowing them suitable flexibility to set dose limits for each radionucleide.

ALARA itself is a source of bafflement. Many believe that exposure to ALARA levels is risk-free but that’s not the case, warns Jean-René Jourdain, head of internal dosimetry at the IRSN, the technical support provider for the French nuclear regulator, the ASN. Low-dose radiation produces the same damage to target tissues as high doses but with lower probability. How much lower is unknown, Jourdain says, because “what we know about low-level radiation was extrapolated from studies on atom bomb victims that were flawed” both in methodology and type of exposure studied.

Chernobyl provided unanticipated results on the effects of cumulative low-dose exposure, Jourdain says. “We expected leukemia in children, instead we found that infants were more prone to thyroid cancer – and much sooner than we’d expected, only five years after the accident rather than 10 to 15 years as we’d thought,” he adds.

SOCATRI added to the bewilderment by providing conflicting information and failing to inform the ASN in a timely manner [4]. As in most countries, the ASN relies heavily on operator data. Based on that, it classified the event, at a level 1 on its scale of 0 to 7. And this is discombobulating because on the ASN web site, an unauthorized off-site release ranks as a more serious level 3. [5]

Furthermore, the ASN waited two days before sending a team on site. “This is normal procedure based on the information given by the operator” Jean-Luc Lachaume, deputy director of ASN says. Even if the operator had released 360kg of radioactive uranium, as initially reported, this wasn’t a problem because the agency knows what the plant releases “it is one of a hundred such incidents in France each year,” he says.

President of the CRIIRAD, an independent laboratory, Roland Desbordes is perplexed by this reasoning because “360kg of uranium is equivalent to at least 9,000 MBq or more than 100 times SOCATRI’s annual limit. Brought down to ‘only’ 75kg the annual limit is overshot by 27 times”.

After the spill, the IRSN monitored radioactivity in surface and groundwater around Tricastin. In a report issued on Sept 4 [6], it found radiation levels three times higher than the national average in marine life and sediments in surface water.

An IRSN study released on Sept. 15, [7] on radioactive water pollution around all nuclear installations found radioactive pollution downstream of and groundwater contamination at nearly all sites. Tricastin again, chalked up some of the highest levels but the IRSN says it can’t identify the source of the groundwater contamination. The CRIIRAD incriminates a mound of radioactive waste buried on site since the 1970s. The IRSN report does point to old waste storage sites, in general, protected by obsolete technology as a source of leakage and pollution, some of it on-going for years. Asked what the ASN would do about the Tricastin mound, Lachaume testily replied that it was a defense issue and the ASN had no authority over it.

With 104 reactors, the US leads in the number of nuclear power plants. The Union of Concerned Scientists and others petitioned the Nuclear Regulatory Commission in 2006 to take action on a similar issue, documenting chronic leaks, some decades-old. [8] “The NRC responded that an industry voluntary initiative, that is by those that have been obfuscating for years, to report the leaks would suffice,” says Paul Gunter of Beyond Nuclear.

Radiation levels around Tricastin have been higher than average for over a decade but this doesn’t worry the IRSN which notes, in the Sept 4th report, that in 1991 (while investigating a previous spill [9]) it found radiation levels five times above the national average. The IRSN implies that since radiation is now lower than in 1991, which has apparently become the standard for “background” radiation at Tricastin, there is no need for concern.

“Background” radiation, often called “natural”, is baffling when confused with “naturally-occurring” radiation. Background includes artificial radiation produced by, among others, nuclear power plants – the more radioactivity is released and stays in the environment, the higher background levels become, explains Jourdain, of IRSN.

All nuclear installations routinely release radioactive liquids or gases. The releases authorized by the ASN and other regulatory bodies are site-specific and cover a variety of radioneuclides. Limits can vary greatly from one country or even from one installation to the next. In France, for example, one installation will be authorized to release 60,000 GBq of radioactive tritium while another is allowed 18,000 TBq [10]. Even allowing for differences in activity and location, these discrepancies can muddle the public mind.

To understand how these limits are set, the example of SOCATRI is enlightening. In 2006, SOCATRI began a new waste reconditioning activity and requested authorization to release 85 MBq/yr of Carbon 14, a low-level radioactive gas. In 2006 and 2007, SOCATRI exceeded it’s authorized levels by 40 times at around 3,400 MBq/yr so it asked the ASN to increase its authorization to 3,400 MBq/yr. The request was granted, Lachaume explains, because “we didn’t know how much would be released at first so we set the levels very low but when it turned out that these were unrealistic, they were slightly revised”. [11]

In June – reported in August – SOCATRI exceeded its annual limit and was shutdown. Lachaume says the Carbon 14 limit will not be raised again but has no suggestion as to how the plant should deal with the problem. “That’s their business,” he says.

In a 2006 review of the ASN, the International Atomic Energy Agency, found that “...some states may encounter difficulties in separating the regulatory control from the promotion and operation of facilities and activities...”. [12] . This is understandable in the newly independent (since 2006) ASN as the State is a majority shareholder in both AREVA and EDF, France’s nuclear utility. But even in the US where the industry is in private hands, the Nuclear Regulatory Commission, headed by five presidentially-appointed commissioners, has been known to ignore safety issues in favor of financial arguments advanced by operators.

In 2002, the Davis-Besse (DB) plant came to within 3/8th of an inch of a nuclear disaster because the bottom line took priority over public safety, NRC records show. Both the NRC and the industry were aware of severe premature aging problems due to boric acid corrosion which plagued reactor vessels world-wide since the 1980s. Yet the NRC allowed the industry to treated the issue as a financial problem, not a safety issue [13]. Loss of coolant can lead to reactor meltdown and massive release of high-level radiation. . In 2001, the NRC suspected DB of serious corrosion issues and told the operator, FENOC, to shutdown by Dec 31 to visually check for and repair corrosion damage.

FENOC planned to shutdown for refueling in April and requested an extension citing the economic toll early shutdown entails. Convinced that safety requirements were not met, NRC staff drafted a shutdown order and sent it to the five-member Commission for approval. But Commission staff questioned the order, requiring 100% proof, available only by shutting the plant, that imposing a financial burden was warranted, a report by the NRC inspector-general shows In the end the NRC allowed the plant to run for an extra six weeks. When workers scrapped off years-old boric acid crud they found that a cavity 7 inches deep and 5 inches wide had bored through the entire outer layer of the reactor lid leaving only the 3/8th of an inch of inner lining to retain the primary coolant inside the vessel [14]. Loss of coolant can lead to reactor meltdown and massive release of high-level radiation.

Plants are aging faster than expected, says Laurent Foucher, IRSN’s head of equipment and structural analysis, and finding replacement parts is becoming difficult.

Tony Pietrangelo, vice president for regulatory affairs at the Nuclear Energy Institute, an industry lobby group, says that “there’s a supply chain issue with ultra heavy equipment.”

Asked if deteriorating plans resulted in more near misses, Scott Burnell, press officer at the NCR says no but adds that “we’re having to deal with more complex situations”.