October 25, 1996
Mr. Stewart Richards
USNRC
Washington, DC 20555
Dear Sir:
In my letter dated February 28, 1996, transmitting INPO Exam Questions alleged to be flawed, the last paragraph contained the following sentence:
As to the references, if the incorrect answers are based on the references indicated, then the references are part of the problem.
In your letter of response dated May 14, 1996, the reference most often cited as supporting nonconcurrence, i.e. in disagreeing that the question was technically flawed, was General Electric, BWR Academic Series, Reactor Theory, 1984. On referring to said document per your comments on Shutdown Margin (SDM), it was noticed that it also contained the incorrect version of the transient period equation. In addition, my copy was marked up from earlier use in Class Room instruction, with the marks identifying errors. In the chapter on Reactor Kinetics, the errors include:
p 3-16 Figure 3-2 : the curvature of the power trace for Tau = -80 seconds is wrong.
p 3-20 Example 3-6: a stable period will not exist to 100 MW, which is well above the POAH.
p 3-28 Figure 3-5: the shape of the lambdaeff curve is wrong, as is the value of lambdaeff at prompt criticality.
p 3-34 Equation 3-9: as previously noted, the transient period equation is wrong.
p 3- 41 Prompt jump: the period response defined as prompt jump and prompt drop is wrong.
p 3-42 Figure 3-8: the identified prompt jump and prompt drop on the period trace are wrong.
p 3-43 Equation 3-7: contrary to the stated claim, this equation is not accurate; it is wrong.
p 3-45 Figure 3-9: this Figure correctly identifies prompt drop as associated with power response, however the shape of the curve near the end of the transient is wrong.
p 3-46 Example calculation: the “typical scram reactivity” is not typical. A reactivity value of -0.9768 requires that the keff be reduced to 0.5059 by scram.
p 3-48 Prompt jump: discussion of prompt jump and prompt drop with respect to reactor power, not reactor period, is correct. However, it contradicts the discussion on p 3-41, as identified above.
These errors are by no means all inclusive, either in Chapter 3 or the entire BWR document. Nor do these errors involve mere trivia, or nit-picking detail. They relate to important basic concepts that are being thoroughly mangled. The impact of this collection of misinformation is nothing less than a near insurmountable obstacle to any students real understanding of the subject of reactor behavior. The potential adverse effect on the student’s subsequent performance in the Control Room cannot be dismissed.
It is clear, this BWR document is the source for many of the flawed INPO questions and also for much of the misinformation about reactor behavior that has remained in circulation for several years. It is the smoking gun. In addition, this BWR document is widely used in License courses as a student textbook. Misinformation on the important subject of reactor behavior from this document pervades the U.S. commercial nuclear program. Not only is it being taught to current BWR trainees, it has been taught to all BWR Reactor Operators licensed in the last 12 years.
In short, this BWR document is THE problem, pure and simple. It should be removed from the program, or undergo major correction, as soon as practical. It should not be endorsed by either the Nuclear Regulatory Commission or by the Institute of Nuclear Power Operations. In the event that you are burdened with other immovable priorities, with limited resources, or with lack the in-house expertise, I am willing to assist, or provide consultation, toward resolution of this entire situation. If the Nuclear Regulatory Commission and the nuclear industry truly strive for excellence, as I believe to be the case, then this matter, being at the heart of Reactor Operator licensing, urgently begs your personal attention.
Sincerely yours,
Robert G. Stater