Invaluable Reactor Safety Reference

, former director, Nuclear Safety Project | February 4, 2014, 6:00 am EST
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UCS Nuclear Energy Activist Toolkit  #23

Bob Pollard directed UCS’s nuclear safety efforts from 1976 until 1996. I took over his work and office in fall 1996. I noticed a tall stack of papers sitting atop a bookcase in his old office. I particularly noticed Bob’s handwritten warning on its top sheet:

NEAT23 Figure 1

The pages that Bob protected in this way and presumably valued so much were a manuscript titled “On the History of the Evolution of Light Water Reactor Safety in the United States,” authored by Dr. David Okrent, a professor in the Chemical, Nuclear, and Thermal Engineering department at the University of California and member of the Atomic Energy Commission’s (AEC) Advisory Committee on Reactor Safeguards (ACRS).

I was unaware of this manuscript prior to seeing it on Bob’s bookcase. I am grateful that Bob left it behind for me (and piqued my curiosity into it). Okrent’s manuscript remains my most valuable reference about U.S. reactor safety. Fortunately, you need not risk life and limb to access Okrent’s information bank. The NRC has scanned it and placed a PDF version in its online electronic library.

Its nearly 1,100 pages are definitely not a beach read. But it is an invaluable (and irreplaceable as Bob noted) reference containing answers to almost every question about reactor safety. Its seven chapters cover areas like reactor siting, the regulatory process, anticipated transients without scram, earthquake hazards, and generic safety issues. As an ACRS member, Okrent had a front-row seat as the AEC and its consultants battled industry representatives. But ACRS members are far more than observers and Okrent shows how ACRS shaped some issues and settled others.

For example, Okrent covers the Ravenswoood reactor and the broader metropolitan siting issue in Chapter 2. Consolidated Edison proposed to construct and operate the Ravenswood reactor on the East River near the Brooklyn Bridge in downtown New York City. The proposal raised a thorny question for the AEC: if the reactors it approved were safe enough for the boondocks, how could they not be safe enough for New York City’s docks? (At risk of giving away the ending to Okrent’s narrative, Con Ed withdrew its application in late 1963 and instead built a second reactor at its Indian Point site a few miles up the Hudson River.)

Okrent describes in Chapter 3 the process leading to the AEC adopting General Design Criteria (GDC). Chapter 3 also describes the quality problems that surfaced (sometimes literally) during the construction of the Oyster Creek nuclear plant in New Jersey.

Okrent devotes all 125 pages in Chapter 5 to earthquake hazards. On page 5-3, Okrent identifies seismically induced floods as one of four factors that must be properly addressed in order to adequately protect against earthquake hazards—an observation from pre-1975 that Fukushima would validate in March 2011.

Bottom Line

Okrent’s manuscript is invaluable for explaining the pathways to regulatory decisions. For example, when I worked for the NRC in 2009 and 2010 teaching boiling water reactor technology to NRC employees, I covered the evolution of emergency core cooling systems and containments from the earliest reactors (Big Rock Point in Michigan and Dresden Unit 1 in Illinois) to the most recent (Grand Gulf in Mississippi and Clinton in Illinois). Students wanted to know why some of the changes had been made—did General Electric voluntarily incorporate new design features or did AEC compel the changes? After not finding the answer in several documents, I found it in Okrent’s manuscript.

Okrent’s manuscript will not explain why the NRC issued a White finding last year for a degraded emergency diesel generator at a reactor, but it will explain the role and importance of emergency diesel generators in reactor safety.

If your hard drive (or book shelf) only has room for one reactor safety reference, you won’t go wrong with Okrent’s manuscript filling that space. If you have space for one more reference, you won’t go wrong adding the manuscript to your collection.


The UCS Nuclear Energy Activist Toolkit (NEAT) is a series of post intended to help citizens understand nuclear technology and the Nuclear Regulatory Commission’s processes for overseeing nuclear plant safety.

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  • Richard

    Thanks for sharing this valuable resource. Many of us lack the technical expertise and/or the time to wade through something as long as this. Thus, it would be helpful if you provided brief, readable summaries like this one. Perhaps one a month while still providing your other weekly info would be good?

  • Sean McKinnon

    (Regarding the comment above) Right, why would anyone put any effort into learning and doing ones own independent research to form a knowledgable opinion on a subject when you can just have someone else tell you what to think and give you the information summarized with their editorial bias. I mean come on why waste time thinking for yourself when you can have someone else do it for you.

  • Joyce Agresta

    “On the History of the Evolution of Light Water Reactor Safety in the United States,” authored by Dr. David Okrent, a professor in the Chemical, Nuclear, and Thermal Engineering department at the University of California and member of the Atomic Energy Commission’s (AEC) Advisory Committee on Reactor Safeguards (ACRS).

    Significantly important manuscript providing help to mankind.

    Steadfast and upright this will in condensed form be understood by the masses.

    • Richard

      Thank you, Joyce, for a helpful suggestion as opposed to the sarcastic reply from Sean. The tone of what he wrote suggests that he, too, has biases to deal with.

      I will put the book you mentioned on my ‘to be read’ list.

  • Joyce Agresta

    Richard, Mr. Pollard addresses the idea that the manuscript may be shortened in his prefix. It’s actually an easy read. Unlike much of the archived documents at the NRC website. Many of which one need actually run through an Enigma Machine or modern simulator with correct settings to get a little closer to the findings. In some cases the studies cited in Mr. Pollards Manuscript may be proven to be understated.

    Thank you Richard for provoking such sarcastic remarks from Sean McKinnon which in turn provoke industry whistle blowers.

    The bias of our trusted experts is no secret the agenda is clearly stated ,Richard citizens like you and I are an important part of the Mission:

    Union of Concerned Scientists Mission Statement
    The Union of Concerned Scientists puts rigorous, independent science to work to solve our planet’s most pressing problems. Joining with citizens across the country, we combine technical analysis and effective advocacy to create innovative, practical solutions for a healthy, safe, and sustainable future.

    • Richard


      Thanks again for your reply. I have been a member of UCS for almost 30 years because I have consistently perceived it as presenting comprehensive information about complex topics in a thorough and straightforward manner.

      Sometimes it takes positions on issues which I believe are, if anything, ‘too moderate.’ Ie, very carefully thought out logical presentations of pros and cons which are nuanced to the complexity of the topic being presented. Its ‘bias,’ if it has any, is to present the facts in a reasoned manner rather than to tout an argument which it has decided on beforehand to be ‘the truth.’

      I have come to rely on UCS as a solid starting point on a whole range of issues from which I can then go on to do some more inquiry of my own if I wish to and/or can commit the time to.

  • David Gaeddert

    So, I have the reference downloaded to my desktop, to study as time allows. Also have the Fukushima book on order, coming by USPS. Thank you very much for the link to the Safety Reference. will stay tuned, let’s see how events develop.

  • Dennis Donnelly


    This is astounding document: instead of outsider-info this is
    what the insiders actually discussed! Here we see, during the
    summer of 1966, that ACRS members actually knew that the
    specified design basis accident (LOCA with full core melt)
    would inevitably lead to breach of containment via China
    Syndrome, and massive release of fission products. They also
    discussed the appropriate design feature that could’ve dealt with
    LOCA and the other known terminal accident, station blackout,
    that should have been a part of all reactor safety designs: this
    appropriate design feature is a steam-driven pump that can
    circulate coolant from a large available pool in the event of a
    station blackout or a serious Loss of Coolant Accident.

    The steam of course comes from the core which isn’t being cooled,
    and will melt very shortly unless coolant is pumped through it.

    Yet the ACRS couldn’t bring itself to require this safety feature,
    and they approved the groundbreaking large reactors Dresden III
    and Indian Point II as-proposed by applicant.

    Of course the first letter in the acronym ACRS is ‘A’ for ‘Advisory,’
    meaning they were granted no real power to oppose the power of the
    AEC and the industry at that time. This leads me to suggest a change
    of name for the NRC, to the ANRC…