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):
http://atomicinsights.com/house-energy-commerce-seeks-enable-advanced-nuclear-energy/

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). 

36. Thresher - SSN 593 (a song)

In about 40 minutes, I will be watching Shovels and Rope play in Mexico. The below post has been saved as a draft since about October 2014 or some such......so it may be out of date. Regardless, I am hoping to hear this song live for the first time tonight. I am not holding my breath, but you never know.


I have recently come across a talented musical duo, known as Shovels and Rope. I purchased their new album "Swimmin' Time" and listened through it several times. On probably the 3rd or 4th listen-through, I caught the lyric "SSN-593" in the final song and immediately thought to myself "SSN, that is the numbering for a nuclear submarine. I should Google 'SSN-593' sometime." I didn't get around to doing a search, and during one of the next listens as I was driving home from a football game, I finally remembered "Oh yeah, the Thresher was the name of a U.S. Navy submarine that was lost."

After that epiphany and once I was safely home, I did some research. Sure enough, the SSN-593 was the Thresher, and there is much that has been learned as a result of the tragic fate of April 9, 1963 (more than 20 years before my birth). This modern song tells the story of the Thresher, in eerily beautiful fashion.

Here is the only video with the song that I could readily find so far on YouTube.

The loss of 129 men (100+ men, in the song) was certainly a great tragedy, but there are many interesting aspects of the Thresher's story. It was the first submarine in its class, which meant that that brand new class of submarines was to be known as the Thresher class (until the Thresher went onto Eternal Patrol).

I heard the names John Wesley Harvey and Jimmy when listening to the song, but I didn't think anything of them the first several times through. After some actual research, however, I discovered that John Wesley Harvey was the ship's commander. Further, I read the story about how

I came across this interesting article discussing John Wesley Harvey's life and found the interesting fact that he played football alongside Chuck Bednarik at the University of Pennsylvania and actually changed positions because Bednarik had the center spot locked down. The Chuck Bednarik Award is given annually to the College Defensive Player of the Year.


In researching for this post, I also came across this song, written in the same era as the loss of the Thresher. Musically, I certainly prefer the song from Shovels and Rope.