Wednesday, March 13, 2013

NUCLEAR VIBRATIONS, REGS., $$$

Note to all who comment here.
This blog does not accept comments whose Anonymous writers promote links to commercial sites.    Their content is  generally unrelated to the topic, also.   All such comments  will be deleted.   



The mechanical phenomenon of vibration assumed intriguing significance to me during my young adulthood when I discovered there were companies devoted to studying and resolving such oscillations negative effects.  I hadn’t given much thought to this subject until I was exploring some employment opportunities and ultimately was offered a position at such a company, though I didn’t accept their offer.     
  
Vibration has “desired” or “undesired effects” as Wikipedia describes.   Tuning fork vibrations, mobile phones, and a reed in a woodwind instrument, like a clarinet, are a few desirable examples.  Undesirable vibrations “...waste energy, create unwanted sound...” and sometimes friction in mechanical devices. 

Years ago our household experienced quite annoying noise every time our refrigerator’s motor came on.  Ultimately we learned vibration was the cause as a consequence of the appliance’s wall contact inside the built-in cabinet.  Vibration effects have been a matter of concern in experimental aircraft test flights, for space flight shuttles, even our automobiles – so many other items, including those we encounter daily. 
  
We’re learning here in So Cal (Southern California, U.S.A.) that tube vibrations inside the coastal San Onofre Nuclear Generating Plant have created a serious problem.  Tubal radioactive steam leakage was discovered January 31, 2012 ultimately necessitating the plant’s shut down.  The Nuclear Regulatory Commission’s analytic report was released March 8, 2013 stating in the Executive Summary on page 6 "...wear was determined to have been caused by random vibration...” in this Los Angeles Times link. 

These tubes had been operating only 11 months, a considerable shorter duration than the years expected.   The newspaper notes the report “...provides the most detailed picture to date of how the flawed system at San Onofre was designed.  It was written by Mitsubishi Heavy Industries, which built the generators.”

So Cal residents such as myself and friends living 50 miles or less from San Onofre are genuinely concerned about our power company’s efforts to have the plant resume operation.  Some of us tend to be a bit questioning about the safety and advisability of doing so given revelations about officials past decision-making priorities. 

Abby Sewell’s L .A. Times article providing the NRC report link mentioned above has written informatively about the issues including wrangling between Mitsubishi and So Cal Edison, our utility company over $$$ which is only part of the problem.  The possible avoidance of correcting known problems because doing so might require seeking additional regulatory approval does little to generate trust in the safety of such nuclear energy plants, certainly San Onofre.    

Resumption of nuclear energy generation by activating even two of the other reactors at San Onofre on the Pacific Coast between Los Angeles and San Diego is yet to be resolved.   

16 comments:

  1. "...wear was determined to have been caused by random vibration...”

    Ah yes, Random Vibrations (or Stochastic Vibrations to the academics) was one of my favorite courses in grad school. Obviously, someone wasn't paying attention in the design or installation of the tubing.
    Cop Car

    ReplyDelete
    Replies
    1. Yes, they made alterations in the design associated with the tubing. Following the ongoing investigation in this debacle, one issue had became a "What did they know and when did they know it?" These latest news reports began with a report leak resulting in this form of the report being released. Clearly responsible individuals needed to better apply what they would presumably have learned in a grad class as you had. Still "random" might be difficult to account for. I don't know if re-submitting for regulatory approval when the re-design was made would have resulted in problem recognition, or if only in actual operation would anyone realize the vibration problem. I haven't read anything suggesting tubal installation was an issue, but could possibly be a concern.

      Delete
  2. Joared--I assume that 99% of the population have no reason to know the difference between "random" and "intermittent" vibrations, so I will clarify: "random" applies to the wave form while "intermittent" means that the vibrations occur at (perhaps) unpredictable intervals, but tells one nothing about the wave form. Known random vibrations can be accounted for in design.

    I went to the report from Mitsubishi from which I learned that the damage to the tubes that is of most interest (at least, to me!) is caused by fluid-elastic instability - which is more than most people care to know, I'm sure; but, which tells us that the problem is truly from "random" vibration rather than "intermittent". In this case, the random vibration is caused by the flow of steam through the tubes and can be predicted from geometry, from the condition of the steam, and from the speed of flow.

    I've probably written 10 times as much as I know considering that I am not a nuclear power engineer!
    Cop Car

    ReplyDelete
    Replies
    1. The term definitions you provide for "random" and "intermittent" give me a somewhat different understanding of them than what I had. Knowing the language with definition of terms in every specialty or business is always so critical. Thanks for your input. The fact engineers would or should have known the form, therefore with mathematical computation could predict the "random": vibrations, makes it even clearer this event didn't have to happen. Human error. Just like small plane accidents -- majority caused by human error.

      Delete
    2. So true, what you say. I should point out, however, that mathematical modeling of the real world is very, very......very difficult. One writes the equations (or uses a pre-packaged app to help do that), then must find a means of checking the results against real world results. I have torn my hair out more than once trying to model, correctly, a small section of an aircraft - let alone matching the real world in the whole airplane.

      We make it confusing for anyone outside our own specialties when we adapt existing words to our specialty. Each of us speaks in her/his own code!
      CC

      Delete
  3. Speaking as a layperson, I say that nuclear power is too dangerous for any engineering to render it safe. Any amount of radioactivity is dangerous, and we are being subjected to unknown amounts of it. And what about the waste generated?
    Hanford is leaking radioactive contaminants. A friend of ours got a tour of this huge installation and said it was pretty clear how nervous the people who worked there were about the place.
    So although it is an interesting technical problem, the real solution would be to do away with the plants altogether and store the waste deep underground.

    ReplyDelete
    Replies
    1. Yes, Hattie, that's the big debate about using nuclear energy, I think. When safety concerns aren't the number one priority taking precedence over all other considerations in the installation and operation of these plants then I, too, reject having these nuclear energy plants. I wonder if the San Onofre's design change had been re-submitted for regulatory review if they would have caught the problem? That's part of the controversy now as our power company, So Cal Edison, proposed re-starting two of the non-leaking reactors without further review.
      Lots of big $$$ on who pays for all this. I'm sure every effort will be exerted to pass the expense to Edison's users which includes me and I resist that. Let the company take a knock, execs and shareholders share in the pain, and accept lower company profit percentages 'til the expense is paid.
      I recall the Big Island has a nuclear energy plant so guess Hanford you mention is its name. I didn't know it was having leakage problems, too. Must be for different reasons than Onofre since I think I read Onofre's the only plant that had this tube re-design.
      Storing all the waste "deep underground" is even worrisome to me as a solution to that problem. I equate it to prevailing thinking for so many years of dumping unwanted materials into our streams, then rivers and the ocean. There's a day of reckoning for all this with consequences of which we may not yet even be aware.

      Delete
    2. No, this is the Hanford nuclear facility in Washington State. Friends from Washington were the ones who took the tour.
      We do not have a nuclear plant here on the Big Island of Hawaii. There are no nuclear power plants in the state of Hawaii. On this island we are generating 40% of our own energy from renewable resources--geothermal, wind, and solar. The rest is gas-fired plants, I believe.
      We ourselves have rooftop solar hot water and photovoltaics, as do two of our immediate neighbors. So we're ahead of the game.
      A big incentive to go solar is the high cost of electricity per kwh. Our neighbors who have not gone solar have huge electric bills.

      Delete
  4. A new friend of mine who is a nuclear physicist PhD said he doubts we'll ever see another nuclear plant built in the U.S. (hooray!). He made a good case that it takes too long to recover construction costs and plants powered by natural gas are much more efficient and safer. We'll also probably see a huge increase in solar and wind power generation, and with government subsidies those energy producers make nuclear non-competitive.

    ReplyDelete
    Replies
    1. Think of the years and years during which "we" have burned off natural gas in extracting oil from the ground. As I understand it, fracking is used (at least, in some cases) in extracting natural gas. Anything that we take out of the ground (including by growing crops) has a long-term impact.
      Cop Car
      P.S. I don't have a PhD in nuclear physics (I switched into engineering half-way to my master's...and then, did not complete the PhD in engineering that I pursued!) but I think your new friend is being optimistic concerning the sanity of the human race. I hope not, of course!

      Delete
    2. We are ahead of the curve where I live, on the Big Island of Hawaii. We generate 40% of our electricity from geothermal, solar and wind.

      Delete
  5. I hope your friend is correct, Dick. Meanwhile we're concerned about how San Onofre energy generation is resolved. Electric power needs in So Cal are significant, especially in the summer. More homes are using solar panels on the roof but their installation cost needs to come down more before homeowners with electric bills below the current cost effectiveness level can afford them. However, if energy costs increase as predicted through the next few years even those homeowners will soon meet the cost effectiveness level. Don't know how long it will take to use natural gas necessitating the need to build new plants, I assume.

    I'm still steaming over how energy rates were manipulated years ago and the federal government authorities failed to see our State received adequate compensation for those crooked dealings as devastating fires burned to the Coast during the Bush presidency. It was part of the Texas Enron fiasco. Californians lives and homes were threatened and lost as one manipulating company's employee was recorded saying, "Burn, baby, burn!"
    http://oag.ca.gov/news/press-releases/attorney-general-lockyer-files-major-electricity-market-manipulation-lawsuit

    ReplyDelete
    Replies
    1. Sadly, people tend to think that such disasters get remediated and fines imposed; but, it's like executing a killer. Maybe it makes us feel better, and perhaps it prevents a portion of future damage; but, it doesn't bring back what was lost.
      CC

      Delete
    2. I agree about fines, CC. The monies I referred to were efforts to have our State reimbursed for this theft of our funds. Whatever it might be called, fine, refund, reimbursement of excessive funds illegally gamed, as long as power users money was returned to the State of California, possibly distributed to individual households forced to pay those unjust high rates, I would have been partially mollified. Not surprisingly, the Federal Govt. Dept's less than positive attitude toward California's situation reflected that of the then unsupportive Administration so we never received amounts we should have.

      Delete
  6. Joared--Sorry that it wasn't clear that I was writing "hypothetically", without reference to the Enron situation. I'm not saying that fines are bad, but that we should not be lulled into accepting assurances that companies/projects will be held to account just because they are subject to fines.
    Cop Car

    ReplyDelete
  7. Years ago, I worked for a corporation with companies in most states. Each company was regulated by a different state regulatory group. I noticed that the quality of regulator varied from state to state. I can only hope and pray your CA regulators are on the ball. Vibrations, leakage, fearsome topics indeed. Dianne

    PS Good to see your comments today, I was hoping you would make another effort to connect.

    ReplyDelete