Advanced Boiling Water Nuclear reactors: doubts on reliability, safety, chemistry

No2NuclearPower nuClear news No.77, September 2015 ABWRs According to World Nuclear News (WNN) there are four operable Advanced Boiling Water Reactors (ABWR) in Japan while two more are under construction. Another two are being built in Taiwan and two planned for Lithuania, although another two have been shelved in the USA. The design is already licensed in Japan and the USA. WNN points out, disturbingly that ABWRs can run on a full core of mixed oxide (MOX) nuclear fuel, raising the prospect of armed plutonium shipments travelling from Sellafield to Anglesey and Gloucestershire. (6)
New Civil Engineer says the four Japanese ABWRs were built to time and budget. (7)  But none of these have a capacity factor above 73% and two have capacity factors of less than 40%. A capacity factor is the amount a plant generates compared to the amount that would be generated if it was operating at full power all of the time.
Nuclear power plants are costed on the basis that they will achieve capacity factors of 80 – 90%. With a capacity factor of 45% any nuclear power project comes out needing twice the power price to be an economic proposition. 12 In fact figures given by the IAEA show that all four reactors had average energy availability factors of less than 50% for the period 2007 to 2011. (8)
This makes the ABWR one of the least reliable reactors in the world. The ABWR at Longmen in Taiwan is still under construction and is over budget and subject to large delays. There are also serious concerns over the safety of the plant both from the risk of earthquakes and Tsunami as well as poor construction and design. This concerns have given a rise to a large number of people opposing nuclear power in Taiwan with the BBC reporting over 200,000 people taking part in anti-nuclear protests. (9)
Hitachi-GE The development of the modular ABWR design was unique, and has led to an unusual situation where it can be offered by three different companies. The ABWR was co-developed by Toshiba and GE, which then worked with Hitachi to construct the first two units in the late 1990s. GE and Hitachi went on to form joint ventures of their nuclear businesses, resulting in two daughter firms: GE-Hitachi and Hitachi-GE. Both those joint ventures can build ABWR, as can Toshiba, although its version differs in some technical respects due to intellectual property issues. (10)
Even assuming Hitachi receives approval for its ABWR reactor it will still need to attract financial backers before it builds reactors at its sites on Anglesey and in Gloucestershire. (11) Dr Tim Fox, head of energy at the Institution of Mechanical Engineers reckons that Hitachi might have a more readily available supply of credit than EDF. He said the fact that eight ABWRs had already been built across the world would be attractive to investors and in all likelihood speed up the licensing process. (12) Given that only four have ever operated this is likely to prove rather an overoptimistic assessment. Hitachi-GE Nuclear Energy, Ltd.” was founded on July 1st, 2007 as a strategic global alliance by Hitachi, Ltd. and General Electric Co. (Its US counterpart is “GE Hitachi Nuclear Energy)” HitachiGE Nuclear Energy, Ltd. offers nuclear power plant construction and maintenance in cooperation with GE Hitachi Nuclear Energy
GDA Process Concerns about reactor chemistry issues related to ABWRs have been raised by UK regulators in their assessment of the design. As part of the generic design assessment (GDA) of the ABWR, the Office for Nuclear Regulation (ONR) and the Environment Agency (EA) raised a regulatory observation in April 2014 requesting Hitachi-GE to define and justify the reactor design’s source terms, amongst other related matters. According to the regulators, “The definition of the radioactive source term; the nature and amount of radioactivity, is a fundamental part in understanding and therefore being able to control the hazards associated with any nuclear facility. Once defined, it is important that the requesting party is able to demonstrate and justify that this source term is appropriate to be used as the basis for the safety and environmental cases. Failure to adequately define or justify the source term could ultimately mean that the design, operations or controls specified for the UK ABWR may not be soundly based.
Hitachi-GE responded with its definition and justification in January 2015. However, the regulators said the responses “do not meet our expectations”. This, they said, “is considered to be a serious regulatory shortfall”. (13)
A second regulatory issue was raised by the regulators in July regarding a series of “shortfalls” in the probabilistic safety analysis (PSA) of the ABWR. The regulators consider a “suitable and sufficient” PSA to be an integral aspect of the UK ABWR’s safety analysis within GDA. “Overall, the UK ABWR PSA information received so far does not provide ONR with confidence that HitachiGE, without further work and changes, will be able to deliver a modern standards full-scope PSA for the UK ABWR, which is suitable and sufficient for ONR to carry out a meaningful assessment within the project timescales,” ONR said.
“This is considered a serious regulatory shortfall which ONR, in line with our Guidance to Requesting Parties, is now escalating to a Regulatory Issue.” (14) Justification Horizon Nuclear power received approval from the Secretary of State for Energy and Climate Change on 28th January 2015 under the regulatory justification process for the ABWR reactortype. (15).
Under this process the operator has to show that the benefits of building a nuclear facility of that type outweigh any detriment that might be caused by discharges of radioactivity into the environment. On 21 January 2015, a committee of the House of Commons (The 9th Delegated Legislation Committee) spent a grand total of 17 minutes examining the decision in favour of the merits of Wylfa Newydd on Angelsey.
A few days later, on27 January, the matter was “examined” in the House of Lords, led by junior energy minister, Baroness Verma, who observed of the project: “it must first undergo a high-level assessment to determine whether its economic, social or other benefits outweigh the health detriment that it may cause.” The entire Lords examination lasted 12 minutes. That’s a total of less than half an hour between two Houses of Parliament. That is surely a scandal! (16)…..” he said.(17)

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