Wednesday, April 6, 2011

Post # 39: Learning From Fukushima

I've made it clear I see no sustainable energy solution apart from relying on nuclear energy for the majority of our base load electrical power generation.   So how, in the long-term,  will we respond to Fukushima?

Short Answer:  The nuclear power industry and nuclear safety regulators will learn and improve. 

The "plan"?

First:  UNDERSTAND WHAT happened at Fukushima.

Second: UNDERSTAND WHY the accident evolved in the manner it did.

Third: UNDERSTAND if and if-so, HOW existing nuclear plants should be modified and future nuclear plants should be designed to cope better with such accidents.

Fourth: COMMIT and ACT upon this new knowledge.

I remember the accident at Three Mile Island (TMI) – which, by the way, was not as severe as the Fukushima event.   I remember how the nuclear industry and nuclear safety regulators mounted a tremendous effort to understand that accident.  I remember that knowledge changed nuclear power – for the better.  New nuclear plant designs such as the AP-1000 and the ESBWR rely much more on passive safety systems for ultimate safety functions.  They have much longer battery life.  The nuclear power licensing process now requires plant designers and owner/operators to consider "Beyond Design Basis" accidents in a manner not considered prior to TMI.

And like TMI,  Fukushima will drive a new era of self-examination, fresh thinking, and safety improvements in commercial nuclear power. 

The learning process has already begun, as William Levis, President and Chief Operating Officer of PSEG Power LLC recently testified before a Senate committee.  Here are a few of my crystal ball predictions regarding some of the impacts of the Fukushima Dai-Ichi events in the months and years to come:

1.  Fukushima will change the way we define common-cause "Beyond Design Basis Accidents".  Fukushima demonstrates that "mega-events" are possible.   "Improbable" is not "impossible".
I defined a mega-event or "Fukushima-like event" in Post # 35, as an event that damages multiple reactor units, compromises an entire nuclear plant site, and negates the ability of the surrounding region to render assistance to the plant.  Generally speaking, such events have not been considered credible in previous reactor safety/risk assessments because the probability of such events has been considered to be below the threshold for consideration.  (Technically, the probability of such events may still be vanishingly-small.  But now one has occurred.)   Here are some examples of potential Fukushima-like events:  
  • An earthquake that leads to the breach of an upstream dam, that leads to a super-flood.
  • An earthquake that destroys the heat removal function of the plant – either by collapsing cooling towers or cooling water inlet structures.
  • A flood that leads to the breach of an upstream dam, that leads to a super-flood
  • A super-solar flare leading to and EMP-like pulse that damages the electrical grid and systems attached to it 
2. Fukushima will catalyze R&D focused on the development of new light water reactor fuel systems that would be less susceptible to over-heating, cladding oxidation / hydrogen production, and severe damage in the event of a Fukushima-like accident than current generation commercial nuclear fuels.


3. Fukushima will catalyze a re-examination of "life-beyond-sixty" or nuclear plant life extension.  The question will be posed, "IF newer plant designs are less vulnerable to Fukushima-like events, shouldn't we replace older plants with newer ones, rather than continuing to operate the older plants?"  This will be a vigorous cost vs. benefit debate when an older plant is providing cheap electricity for it's rate payers and generating $2M/day in profits for its owners...

4. Fukushima will catalyze a re-examination of, and ultimately a requirement for, longer station battery lifetime in nuclear plants.  Four, six, or even eight hours will not be considered sufficient.  (This actually isn't a prediction.  The dialog has already begun.  See: http://www.wnyc.org/npr_articles/2011/mar/31/the-future-of-nuclear-energy-in-the-us/transcript/ .)

5. Fukushima will change emergency response planning for nuclear power plant accidents.  The dialog regarding emergency planning zone (EPZ) sizes will be revisited.  The case for smaller EPZs for small modular nuclear plants (SMRs) will be given greater scrutiny.  


These dialogs will be vigorous, passionate, controversial, and healthy for nuclear power and society.  Like Alvin Weinberg, I believe the nuclear power enterprise bears a special responsibility to warrant, maintain and strengthen the trust and confidence of the public.  And I'm confident the nuclear power industry and nuclear safety regulators are up to the challenge.

Just thinking...

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