AECL Technologies President John Polcyn told NEI that under the current schedule, the Advanced Candu Reactor-700 (ACR-700) could be certified for US use in 2008.
Design certification is a legal process that ultimately leads to a Nuclear Regulatory Commission (NRC) affirmation that the design is acceptable for use in the USA. The design certification rulemaking can be referenced in site-specific licence applications, and issues resolved in the rulemaking cannot be re-challenged in the site-specific licensing. So far, the NRC has issued design certification rulemakings on three advanced reactor designs: the GE Advanced Boiling Water Reactor, the Westinghouse System 80+ and the Westinghouse AP600. The NRC has approved the design certification for a fourth reactor, the Westinghouse AP1000, and currently is in the rulemaking process.
The ACR-700 will present additional challenges for the NRC review team, because it is a different type of technology from the traditional light water reactors (LWRs) that the regulators have considered in the past, Jim Dyer, director of NRC’s Nuclear Reactor Regulation division told a 17 August meeting among AECL, NRC and Canada’s nuclear regulatory agency, the Canadian Nuclear Safety Commission (CNSC). The NRC staff will need a high quality submittal from AECL because the technology is new to NRC, Dyer stressed.
The ACR-700 is an LWR that combines features of Canada’s Candu reactors and LWRs currently used in the USA, Polcyn said. Unlike traditional Candus that use natural uranium fuel, the ACR-700 will use slightly enriched fuel (2.1%), and will use 75% less heavy water than today’s Candus, eliminating the need for a heavy water cleanup system.
A sunny future for AECL? How a twin ACR-700 plant might look
ACR-700 FOR VIRGINIA?
A four-member consortium led by Dominion has submitted a $500 million proposal to the Department of Energy (DoE) to examine the feasibility of building the first ACR-700 in the USA, using the North Anna nuclear power plant in the state of Virginia as a reference site. Under DoE’s Nuclear Power 2010 programme, the consortium and DoE would each pick up half of the costs of the six-year effort to develop a ‘success path’ to submission to NRC of a combined construction and operating licence (COL) for the North Anna ACR-700.
Dominion will serve as team leader, provide a site and provide up to $61 million in funding; AECL Technologies will provide the remainder of the consortium’s portion of the funding. Hitachi America will provide work on the secondary (steam) side of the plant and Bechtel Power will provide support in engineering and for COL preparation.
Even if it receives the COL, Dominion is not committed to building the plant. The company will make its construction decision in the future, based on the need for baseload power and the comparative advantages of the ACR-700 against other power supply options, said Dominion spokesman Richard Zuercher. If Dominion decides to proceed with construction, AECL Technologies could have the first 753MWe unit in operation at North Anna by October 2013, Polcyn said.
AECL has spent almost two years in pre-application discussions with the NRC on the design certification, and is now preparing to move into the more formal, legal process that will be triggered by the submission of its application. Pre-application reviews are not mandatory and the applicant, rather than the NRC, chooses the scope of discussions, based on what issues it wants resolved prior to submitting its application, Jerry Wilson, a senior policy analyst with the NRC’s Office of Nuclear Regulatory Research, told the August meeting. Pre-application reviews are used to identify technical and policy issues prior to the certification review.
“Design certification will be a lot different than the pre-application review,” Dyer said. A lot of communications challenges between the NRC and AECL must be overcome if certification is to proceed on the schedules discussed, and AECL’s submissions must be timed to mesh with NRC staff and commission schedules.
However, AECL has worked closely with the NRC over the pre-application period to define the issues that need to be resolved, and AECL has come away from recent discussions with NRC staff confident that a 43-month schedule from submission of the application to final rulemaking on the design certification is achievable, Polcyn said. Under this schedule, AECL would have the design certification in hand by October 2008, which would support an in-service date for the first unit in 2013.
During the pre-application period, AECL worked closely with the NRC to assist the regulator in developing expertise in those reactor design areas that differ from the current generation of US LWRs, including pressure boundary issues and code classifications, Polcyn said. “We spent the first year conducting familiarisation meetings with NRC staff and committees,” including the Advisory Committee on Reactor Safety. “NRC has said this approach has been very effective,” he added.
AECL’s design certification application must include an essentially complete nuclear power plant design, final design information, resolution of all safety issues and finality for resolution in subsequent proceedings, Wilson said. A number of issues will not be included in the NRC’s design certification review and must be handled as part of site-specific licence applications, he said. These include site-specific safety issues (such as seismology or meteorology); environmental protection issues, with the exception of severe accident design alternatives considerations under the National Environmental Policy Act (NEPA); site-specific features, such as cooling towers; licensee information, such as operational programmes; and rapidly evolving technology.
“The only way to understand everything the NRC will use in the review process is to sit down with reviewers and have them tell you what they will use,” Wilson told AECL. At the August meeting, Polcyn told the NRC that his company would prefer to do this “sooner, rather than later,” and Wilson agreed this was the best approach. Wilson also said the NRC would look at design features to determine if they can be inspected adequately once they are built.
During the pre-application discussions, the NRC Office of Nuclear Regulatory Research identified several key areas it will review during design certification, said Marsha Gamberoni, acting chief of the office’s advanced reactors branch. These are thermo-hydraulics, severe accident scenarios, nucleonics, instrumentation and control, materials and probabilistic risk assessment.
Support from NRC chairman Nils Diaz has been critical during the pre-application period, Polcyn told NEI. Diaz has told the staff “not to re-invent the wheel,” and encouraged extensive discussions between the NRC staff and committees and the CNSC. Polcyn explained that the ACR-700 licensing effort already has forged a much stronger relationship between the regulators – staff members have repeatedly visited each other’s facilities.
PARALLEL EFFORTS
The CNSC is conducting a parallel licensing effort on the ACR-700 because a number of potential customers in Canada have expressed interest in the new design. Ian Grant told the August meeting that the Canadian regulator is currently doing a licence review for the ACR-700 design. The CNSC has completed a licensability review, which Grant compared to NRC’s pre-application review. Like the NRC, the CNSC is taking a thorough look at the ACR-700 because of the amount of innovation compared to traditional Candu reactors.
The CNSC is very interested in observing NRC design certification processes, Grant said, adding that the regulator “would like to see if parts of it are applicable to Canada.”
In Canada, AECL is spending $1.5 million each week on the ACR-700, with 380 people working on the design and Canadian licensing, Polcyn said. Along with potential Canadian customers, a number of other countries such as China, Korea and Romania have expressed interest in the ACR-700.
One of the advantages of the close cooperation between the American and Canadian regulators is that there are likely to be a minimal number of differences between the US and Canadian versions of the ACR-700. “No differences would be the best,” Polcyn said.
Polcyn predicted Canada would be the first to licence the ACR-700. Like Grant, he noted that the CNSC does not have a design certification process, but does have a suitability-for-operation determination. AECL is talking with several sites in Canada, and hopes to begin the two-year environmental assessment (EA) process on the ACR-700 by the end of the year, and have approval of the EA by late 2006 or early 2007.
AECL’S NEW WAY
Along with an innovative reactor design, AECL also is pioneering a new way of building nuclear plants using industrial technology developed since the last US plant was built. These new techniques, based on the use of global markets and global supply chains, also will change the way the ACR-700 is licenced in the USA and abroad.
In the past, US nuclear power plants were built or assembled almost entirely at the operating site, with NRC inspectors present during the construction. Large portions of the new plants will be built at remote locations in the USA or abroad and shipped intact to the plant site for final integration.
One key selling point for the ACR-700 is its ability to plug into the very mature supply chain base already used to build Candu reactors around the world. “That’s why we can offer a fixed price and a fixed schedule,” Polcyn said. Suppliers are willing to make very good offers because they see large future markets if multiple units are sold over the next few years.
This extensive supply chain also means that it would be possible for Dominion or other potential buyers to specify what parts of the plant they would like to see made in USA. “The only thing we can’t make in the USA is the steam generators; we have to go to Japan for these large forgings,” Polcyn told NEI.
AECL is studying the possibility of standardising the entire plant, which would include more than 300 modules. Some of these modules would probably be built in shipyards, possibly outside the USA so the NRC would have to change its inspection methods, Polcyn noted. For example, the NRC is looking at regional inspectors, both in the USA and abroad. Fabricators would know where to put ‘hold points’ in the process that would allow one regional inspector to cover two or three shops located in a single region.
For some modules made abroad, particularly those made in Canada, the NRC is looking at the possibility of contracting with the CNSC or another regulator in the fabricator’s home country, Polcyn said. The NRC would train foreign inspectors in US methods, and then contract for inspections before modules were shipped to the USA.
If Dominion moves forward with a COL application, the Inspections, Tests, Analyses and Acceptance Criteria (ITAAC) section will be the final point for laying out its procurement strategy. AECL will work with the NRC’s construction inspection group to develop a fully integrated basis for inspections and analyses. Binding this inspection plan to the finer points of the schedule “is going to be a real logistical challenge, but one we’ll have to make work,” Polcyn said, adding that the “first time out of the gate will be the hardest.”
In the years since the last US nuclear plant was built, a large number of industries around the world have switched to modularised fabrication. AECL has an advantage here because it already uses modularisation to build current-generation Candus around the world. “We can articulate a strategy and plan to the NRC so that they can buy in and help make it work,” Polcyn explained. He added that the NRC has not expressed any problems with this approach, but the regulator does realise that the logistics need to be worked out.
This is an issue the NRC must consider even with the current generation of US LWRs. As an example, Polcyn pointed out that all reactor vessel heads being retrofitted on US reactors are coming from overseas. The NRC has done inspections in the fabricators’ shops to make sure that the vessel heads meet US standards before they are shipped into the USA.
These global supply chains – as well as ease of inspection – also will benefit from the increasing harmonisation of machining and other standards around the world, Polcyn said. The use of global supply chains in a number of industries is making this a necessity. Every American-made car uses components made in Japan, Mexico and a host of other countries. A large number of parts for US military aircraft are coming from offshore. “The nuclear industry cannot be any different.” Standardisation will come quickly as long as the market is there, he said, adding that he thinks standardisation will be a non-issue for the nuclear industry because it is part of a worldwide trend.
WASTE
Recognising that nuclear waste remains the great uncertainty in the nuclear field, AECL and Dominion are discussing including the Canadian MACSTOR (Modular Air Cooled Storage) dry spent storage system at a potential North Anna ACR-700 that would have sufficient capacity to store spent fuel for the entire life of the plant, Polcyn said.
AECL describes MACSTOR as an advanced dry storage system that incorporates highly efficient heat-rejection and shielding capabilities and can be used to store used fuel from any type of reactor. It can save up to one-third of the space required by comparable systems and permits easy fuel removal. MACSTOR is already licensed in Canada, and is currently used at Canada’s Pickering and Bruce nuclear power plants. AECL also has sold MACSTOR to customers around the world, such as Romania’s Cernavoda nuclear power plant.
Polcyn also pointed out that, in the long term, easy retrievability could be an advantage if industry and government start to consider spent fuel a resource. Candus can burn spent fuel, he notes. The ACR-700 also will be capable of burning LWR spent fuel, but with a bit more processing than is required by the traditional Candus.
He stressed, however, that these are decisions for the future and are not part of the current licensing process in either the USA or Canada.
AECL would be very open to discussions with Native American nations in the USA or Canada that were interested in siting an ACR-700 on tribal lands, either for their own power use or as a source of revenue from sales to the electricity market, Polcyn said, noting that there has been some very preliminary discussions of this possibility.
Openness and getting issues on the table early are key components of AECL’s licensing strategy and will continue to be central, Polcyn said. He expects that this same emphasis on openness will carry over into AECL and Dominion’s dealing with the public at North Anna. Dominion has been very proactive in involving the public in its licensing effort, he noted. The Canadian experience also will stand the effort in good stead. “Once the public sees how AECL and the Canadians are so open and don’t try to hide anything, they will have a greater appreciation for the candour of the process and feel more comfortable.”
FilesACR-700 licensing and deployment plan
