Atomic Insights

GEH spent about half a billion dollars designing, testing and certifying the ESBWR. Despite that investment, the 1,520 MWe Enhanced, Simplified Boiling Water Reactor (ESBWR) design documents are just gathering dust with no active projects in sight.

GEH is a joint venture between US-based GE, a $95 billion annual revenue conglomerate and Hitachi, a Japanese technology leader that is in the same corporate weight class as GE.

Inside both companies, nuclear power is a relatively minor and often-neglected business unit.

A small, but growing group of people working at GEH believe they have found a way to extract value from the trove of already reviewed and approved ESBWR licensing documents. They know that the ESBWR design has many positive attributes, but the product packaging, size and marketing are not well suited to the current power and heat market.

GEH’s new X-300 power station design is a rethought and repackaged ESBWR. The company believes they have successfully addressed the factors that convinced customers the ESBWR wasn’t worth building.

On Monday, March 30, I spoke with David Sledzik, SVP Sales and Product Management at GE, to learn more about GEH’s X-300 development and deployment plans.

Utilities don’t want to be first in line

One hard lesson from the slow start of the Nuclear Renaissance is that utility companies – and competitive power generators that used to be utilities – do not want to be first. They are interested in building proven machines that can be delivered at a predictable price on a predictable schedule. They won’t buy incomplete designs anymore.

Neither corporate boards nor public utility commissions will approve the almost open ended investments that are an inevitable feature of FOAK projects.

The federal government created the Advanced Reactor Demonstration Program as a partial solution to the first mover avoidance problem. That program will help to fund construction of two demonstration projects that can be completed within five to seven years of the government’s final contract award.

The ARD program will require a significant matching investment from private company participants, but many believe the direct federal investment reduces the risk into the acceptable range.

Note: It is important to keep in mind that no one is promising that they will be able to complete a project by a certain date. The clock cannot start running until primary contracts are in place. No doubt there will be people who forget that fact when they begin criticizing and claiming missed deadlines

The financial boundaries of the ARD program encourage smaller projects.

GEH is part of a coalition of companies that will be responding to the DOE’s promised solicitation with a proposal that will include the first X-300 as the target demonstration technology.

5 times smaller version of already licensed design

The X-300 is fundamentally a smaller version of the ESBWR. That fact turns GEH’s investment in licensing the 5 times larger machine from a write off stored on a dusty shelf to something with real value.

Instead of starting a licensing review from scratch, GEH will submit licensing topical reports (LTR) that cover the differences between the X-300 and the ESBWR. These reports will allow the company to incorporate the previously approved features and analysis by reference, eliminating the need to do a full review.

That process started several months ago. On Jan 30, GEH announced that it had submitted the first LTR for the X-300 at the end of 2019.

Sledzik told me that the NRC expects a 12 month review cycle on each of the LTRs. Numerous reviews can be conducted in parallel.

The company has determined that the two step, Part 50 licensing process is better suited than the one step, Part 52 process to a first of a kind development project. Part 50 will enable earliest possible completion and operation. Part 50 licensing means that construction can be started after a preliminary safety analysis and a issuance of a construction permit.

Even though using Part 50 licensing, the company and its partners will carefully approach construction sequencing. They need to be confident that they will not be slowed by significant redesign or need to rebuild already completed portions of the plant.

Smaller plants are easier to cool

It’s almost trite to point out that smaller nuclear plants produce proportionally less decay heat. It’s also obvious that it’s easier to cool cores with a smaller number of traditional fuel assemblies.

Based on design calculations and model simulations, GEH believes that the X-300 design can passively cool itself for at least 7 days without any external power or need for operator intervention.

Smaller plants are easier to build

Conventional engineering scaling laws say that cost per unit of output power should increase for a smaller unit. But those scaling laws do not recognize the importance of packaging costs.

As part of its design-to cost effort for the X-300, GEH has found a way to shrink the total size of the power plant – including buildings and supporting systems – by 90% when compared to the ESBWR. Even with a power output reduction of 80%, the result is that X-300 uses half as much material per unit power.

Using safety grade concrete as a useful comparison metric, the 1520 MWe ESBWR needs ~100 m^3/MWe; the 300 MWe needs ~50 m^3/MWe.

Another construction advantage of a smaller reactor core and the associated narrower containment structure is that the resulting system dimensionally fits within the capability of tunnel boring equipment.

Compared to traditional excavation techniques, tunnel boring machines can substantially reduce the time required to create the 40 meter deep hole that will house the reactor and containment portion of the X-300.

Advanced construction techniques will enable the containment structure to be assembled above ground and then sunk into the hole created by the boring machines. A significant design and testing effort is required to convince regulators that the containment system can be properly inspected both before installation and throughout the life of the reactor plant.

One advantage that GEH has over many of its competitors in the business of building smaller nuclear plants is that it is part of a conglomerate with a large steam turbine and generator division. GE’s steam power plant unit has deployed approximately 200 turbine generator sets that are virtually identical to the 300 MWe sets that will be paired with the X-300 reactor steam supply system.

Utilities are interested and investing

Though no utility has made a commitment to build an X-300, at least one utility, Dominion, has publicly announced that it is investing and participating in the X-300 development.

I spoke to Dan Stoddard, Dominion’s Chief Nuclear Officer, on Tuesday, March 31. Though he was careful to remind me that Dominion does not have any plans to build an X-300, he explained why his company was interested enough to make some “modest” investments in the technology development.

Dominion is committed to steadily reducing CO2 emissions. The company has recognized and is taking advantage of the steep cost reductions in solar power systems, but it believes there are limits to the total amount of solar power their system can accommodate while maintaining system reliability.

He acknowledged the fact that there is great enthusiasm about energy storage, but reminded me that 4 hours of storage is far from the amount needed to cover routine nighttime demands. When it comes to seasonal variations in solar power, existing forms of storage cannot begin to cope with addressing the challenge within any kind of reasonable cost.

So Dominion believes that nuclear energy is necessary to achieve CO2 emission goals, but the company isn’t interested in taking a “bet the company” risk. If expectations can be achieved, the X-300 appears to be a good fit for needs that will begin to rapidly grow in the late 2020s through the 2050s.

The projected cost of the plant – perhaps $700 M for a 300 MWe Nth of a kind unit – fits within the normal financial capability of the company. (That number is computed from company’s announced target of $2,250/kWe with a margin for error and using a more appropriate, single-significant-digit precision.)

The moderate power output means that it would be possible for the company to build several follow-on units on the same site without overwhelming transmission systems or causing major system bottlenecks.

Despite its history of increasing costs, the nuclear industry has successfully lowered costs for succeeding units on the same site. Project managers learn to improve scheduling efficiency, workers learn their jobs, permitting challenges smooth out, and supply chains strengthen. Even Plant Vogtle, no one’s shining example of excellent cost and schedule performance, has demonstrated significant improvement between unit 3 and unit 4.

Stoddard indicated that Dominion wasn’t the only utility interested and involved in the X-300. He wasn’t willing or able to name others or to give me any hints on which sites are under consideration to be the place where the DOE-sponsored demonstration will be built.

Bottom line is that GEH’s X-300 is a formidable competitive entrant into the smaller reactor field. If the company fully supports the project with its considerable financial and political heft, the product could be a resounding success.