Invaluable Reactor Safety Reference

February 4, 2014
Dave Lochbaum
Former contributor

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.