Tuesday, May 3, 2016

34. What is an Advanced Reactor

Early today, I saw a response to a tweet from David Roberts (@drvox on Twitter) that had posed a good question.

The term "Advanced Reactors" definitely doesn't have a hard and fast definition, unfortunately. Also, there are the Generation I, II, III, III+, and IV terms thrown around for different generations of reactors that possess different features in terms of technological advancements, fuel utilization, economics, and safety features.

These Reactor Generation designations are not incredibly well-defined, much less well-defines than the 300 MWe cut-off under which a reactor would be considered an SMR (small, modular or small or medium reactor).

Are Britain's gas-cooled reactors designed in the 1950's Gen I or Gen II?

Is it possible to have a water-cooled reactor that is Gen IV......even a super critical water-cooled reactor (according to the title of this .pdf, apparently yes for the super critical concept)? Or is substantial fuel breeding a prerequisite for "qualifying" as Gen IV?

Would the thorium breeding for Shippingport's final fuel load (additional writeup from Rod Adams) make that obviously Gen I reactor be closer to being a Gen III for that fuel cycle, since fuel was bred.........with the lack of "more modern" technology (lack of passive safety features.........or maybe Shippingport did have passive safety features?) and being literally the FOAK land-based PWR preventing it from being Gen IV (or even II or III)?

I chimed in with my present understanding (which has been painted by a few recent happenings).
Then I mentioned a few of the happenings.
As was mentioned in my Twitter response, I feel like the following 3 "advanced reactor" items are referring to non-light water cooled reactors (counting the 2 bills as a 1 of the 3). The Advanced Reactor Design Criteria (presently under a public comment period) are certainly explicitly geared that direction. The Nuclear Innovation Alliance also recommendations also seem to be geared that direction (with a big emphasis on how the licensing process relates to the confidence needed for investment capital to be risked).

The NRC's present licensing process is tailored to light water reactors (LWRs), and does not presently lend itself to licensing molten salt, molten salt-cooled/solid-fueled (like Per Peterson's "FHR"), gas-cooled, sodium-cooled, lead-cooled, etc. reactors. 

NRC comment period on Advanced Reactors:

Strategies for Advanced Reactor Licensing:

Nuclear Energy Regulatory Modernization Act:

Nuclear Utilization of Keynote Energy Policies Act (horrible bill name):

In conclusion, my thoughts are that although the Westinghouse AP1000 is a Gen III reactor and the A in its name is for "advanced", I would say that most of the recent discussion of "advanced reactors" is not referring to the AP1000 (or the APR1400 or any other iteration of a PWR or BWR) geared much more towards reactors designs other than light water-cooled reactors (LWRs, which includes pressurized and boiling water reactors [BWRs]) or CANDUs (which are cooled by heavy water).