Nuclear News - Nuclear Monitor #823 - 4 May 2016

Nuclear Monitor Issue: 

The checkered history of high-temperature gas-cooled reactors

Princeton University academic M.V. Ramana has written a useful summary of the troubled history of high-temperature gas-cooled reactors (HTGR) including the pebble-bed reactor sub-type. In the past, both Germany and the United States spent large amounts of money to design and construct HTGRs, four of which fed electricity into the grid. Other countries have also invested in HTGR technology. Ramana's analysis is of more than historical interest as several countries are either considering the construction of new HTGRs or pursuing research into the field.

Ramana writes:

"Proponents of HTGRs often claim that their designs have a long pedigree. ... But if one examines that very same experience more closely – looking in particular at the HTGRs that were constructed in Western Europe and the United States to feed power into the electric grid – then one comes to other conclusions. This history suggests that while HTGRs may look attractive on paper, their performance leaves much to be desired. The technology may be something that looks better on paper than in the real world ...

"Although Germany abandoned this technology, it did migrate to other countries, including China and South Africa. Of these, the latter case is instructive: South Africa pursued the construction of a pebble-bed reactor for a decade, and spent over a billion dollars, only to abandon it in 2009 because it just did not make sense economically. Although sold by its proponents as innovative and economically competitive until its cancellation, the South African pebble-bed reactor project is now being cited as a case study in failure. How good the Chinese experience with the HTGR will be remains to be seen. ...

"From these experiences in operating HTGRs, we can take away several lessons – the most important being that HTGRs are prone to a wide variety of small failures, including graphite dust accumulation, ingress of water or oil, and fuel failures. Some of these could be the trigger for larger failures or accidents, with more severe consequences. ... Other problems could make the consequences of a severe accident worse: For example, pebble compaction and breakage could lead to accelerated diffusion of fission products such as radioactive cesium and strontium outside the pebbles, and a potentially larger radioactive release in the event of a severe accident. ...

"Discussions of the commercial viability of HTGRs almost invariably focus on the expected higher capital costs per unit of generation capacity (dollars per kilowatts) in comparison with light water reactors, and potential ways for lowering those. In other words, the main challenge they foresee is that of building these reactors cheaply enough. But what they implicitly or explicitly assume is that HTGRs would operate as well as current light water reactors – which is simply not the case, if history is any guide. ...

"Although there has been much positive promotional hype associated with high-temperature reactors, the decades of experience that researchers have acquired in operating HTGRs has seldom been considered. Press releases from the many companies developing or selling HTGRs or project plans in countries seeking to purchase or construct HTGRs neither tell you that not a single HTGR-termed "commercial" has proven financially viable nor do they mention that all the HTGRs were shut down well before the operating periods envisioned for them. This is typical of the nuclear industry, which practices selective remembrance, choosing to forget or underplay earlier failures."

M. V. Ramana, April 2016, 'The checkered operational history of high-temperature gas-cooled reactors', Bulletin of the Atomic Scientists,

All Belgians likely to be issued with iodine tablets

The entire population of Belgium is likely to be issued with iodine tablets, which help reduce radiation build-up in the thyroid gland in the event of a nuclear accident or terrorist attack.

"Before, the iodine pills were only given to people living in a perimeter of 20 kms — now we are going to take measures for people within 100 kms," Health Minister Maggie De Block said on April 28. "We will provide iodine pills in the whole country."

All 11 million Belgians live within 100 km of a nuclear power plant when reactors in Belgium, France and the Netherlands are taken into account.

The announcement followed advice from Belgium's Superior Health Council. The Health Ministry said it would take the advice into account as it revises safety protocols to be finalized before the end of the year, but the Minister's statements indicate that a firm decision to accept the advice has already been taken.

"We are a very small and densely populated country surrounded by nuclear power plants both in our country and neighboring countries" and iodine pills are "cheap and efficient," said Nele Scheerlinck, a spokeswoman for the Federal Authority for Nuclear Control.

Belgium's nuclear industry has been subject to numerous security threats and scares as discussed in Nuclear Monitor #822. In addition, there are serious safety concerns including multiple cracks discovered in the Doel 3 and Tihange 2 pressure vessels and a controversial decision to allow the reactors to restart. German Environment Minister Barbara Hendricks said last month that Belgium should take offline Doel 3 and Tihange 2, which are close to the German border, because of safety concerns.

Protesters break into Finnish nuclear site, police attack

On Chernobyl Day, April 26, anti-nuclear protesters broke in to a Finnish construction site for a nuclear reactor to be supplied by Russia's Rosatom. Protesters said more than 100 people participated, while police estimated that close to 50 protesters gathered near the Fennovoima site and around 40 were detained. One group broke into the site while others lay down on the road leading to the site's entrance.

"We want to remind people that the Chernobyl plant was built by Rosatom's predecessor. I wouldn't do business with anyone with that kind of history," said Venla Simonen from the Stop Fennovoima protest group.

Site works have been ongoing for one year, and a protest camp has recently celebrated its first anniversary. The camp was able to stay inside the construction area over five months and was able to slow down construction works. During the summer of 2015, dozens of blockades took place. In September, after an eviction that lasted eight days, the camp moved outside the construction site to continue its activities with help from local supporters. Blockades and other activity against nuclear power did not stop at any point.

Protesters organized multiple actions in the week around Chernobyl Day. They blocked the road to the Fennovoima-Rosatom site on April 28 before the police attacked. Some people locked themselves together with pipelocks and some of the people locked on to heavy barrels. The activists had locked themselves to locks inside the barrels, and there were activists locked on to the barrel-activists, so they formed a human chain to block the traffic on the road.

It took almost three hours for the police to arrive at the blockade. But when they came there was a lot of them and they had riot equipment and police dogs. A helicopter circulated around the area. Police used rubber bullets and pepper spray and dismantled the blockade. Many protesters were taken to the custody. Police also attacked and destroyed two protest camp sites at the Fennovoima site.

Protesters said: "We don't accept giving in to repression and police violence, and the struggle against Fennovoima will continue. Now we'll need everyone to help build up the camp again, and to continue the fight and actions against Fennovoima. We invite comrades to this fight where ever you are – let's aim our actions towards the companies which are working with Fennovoima, the embassies of Finland, or the local police."

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