NUKEFACT #66

last update November 1, 2001

As stated in earlier letters to the NRC, the cause for concern with this wholesale error is that Training Centers rely heavily on the INPO test items and NRC Exam Questions in developing and supporting their instructional programs. The net result is that approximately 42% of classroom fundamentals instruction in Reactor Theory given to reactor operator candidates is misinformation and error.

In a July 6, 2001, NRC letter responding to the 42% INPO Catalog error, Samuel J. Collins, Director Office of Nuclear Reactor Regulation, indicated that INPO had taken 23 separate actions related to test items in its 1994 BWR Generic Fundamentals Examination Catalog, and that most of these actions involved terminology-based changes to the test items that effectively improve the psychometric and technical accuracy of those items. In total, 280 technically incorrect questions were submitted. Since no mention is made of the other 257 technically incorrect questions, it must be assumed that neither INPO nor the NRC recognizes any error in these. In addition, Mr. Collins states that, "We did concur with INPO that in no instance would any item flaw have caused any safety concern." This is the bogus NRC criterion used for not correcting training error, "what is in error does not matter as long as it doesn’t cause a meltdown." This is an absurd and untenable criterion for removing error and enhancing the quality of operator training.

Mr. Collins also states:

"The NRC GFE examination bank now contains over 3000 PWR and BWR validated test items. As we have discussed with you in earlier letters, these items undergo a high degree of scrutiny from the developer, the NRC, and finally from industry personnel who, themselves, take and review the examinations before the items are placed in the test bank for future training and examination use. Because of all the quality control measures taken for this examination, we believe the NRC GFE bank consists of technically accurate and psychometrically sound items that measure generic fundamentals knowledge. We invite you to explore this website to review the quality of our NRC GFE test banks and the items within."

Apparently, Mr. Collins was unaware that I had already reviewed the NRC GFE test banks on the NRC website and had submitted a letter to Chairman Meserve on April 13, 2001 which stated:

"A review of the Reactor Theory sections for BWR and PWR finds that, contrary to Mr. Collins’ claim, the many errors contained in the INPO Catalog do exist in the NRC GFE bank. Error types include plain misinformation, garbled terminology, mistaken definitions, contradictory test items, erroneous terminology, lack of adequate definition of initial conditions, erroneous equations, misapplication of equations, and false concepts."

For those of you who did not have the time or the inclination to read through this horrendous litany of error in the NRC Exam Questions, the following list is a summary of the errors that INPO and the NRC are propagating. Nearly all of these errors have been addressed in detail in individual NUKEFACTs or in the NUKEFACTs that specifically list the individual Exam Question errors.

1. Beta is NOT the delayed neutron (population) fraction.

2. Beta-effective is NOT the fraction of fissions caused by delayed neutrons.

3. Prompt neutrons do NOT always account for more than 99% of fissions.

4. Delayed neutrons are NOT insignificant at prompt criticality.

5. Energy equilibrium with surroundings is NOT unique to thermal neutrons.

6. Non-fission neutrons are NOT the principal neutron source.

7. The reactor operator does NOT have knowledge of neutron source strength.

8. Source multiplication is NOT limited to the subcritical reactor.

9. The NRC source multiplication equation does NOT apply at criticality.

10. Reactor 1/M Loading curves are NOT non-linear because of geometry.

11. Chain reactions are NOT self-sustaining at criticality.

12. K-effective does NOT apply directly to actual chain reactions.

13. The RO does NOT always have knowledge of the value of k-effective.

14. K-excess is NOT defined by (k_effective - 1).

15. Shutdown margin is NOT a condition with all control rods fully inserted.

16. Reactivity margin to criticality is NOT meaningful terminology.

17. Shutdown margin is NOT the reactivity by which a reactor is subcritical.

18. Depletion of burnable poison does NOT reduce shutdown margin.

19. The neutron lifecycle model can NOT explain actual reactor behavior.

20. Generation time does NOT account for reactor controllability.

21. Prompt neutrons do NOT possess a property called generation time.

22. Delayed neutrons do NOT possess a property called generation time.

23. The NRC generation time equation for lifecycle neutrons is NOT correct.

24. Reactivity is NOT a property of anything except of the core.

25. Reactivity change is NOT synonymous with reactivity.

26. Reactivity is NOT added to the core by any change in property of the core.

27. Reactivity change does NOT represent delta-k/k.

28. Reactivity coefficients are NOT defined by parameter change.

29. Reactivity coefficients do NOT become more, or less, negative.

30. Reactivity alone does NOT determine the direction of power change.

31. Reactor power is NOT defined by a proper general equation.

32. Reactor period is NOT defined correctly by the NRC equation.

33. Stable reactor rate can NOT exist in the power range.

34. Transient reactor rate response is NOT unaffected by rho-dot.

35. Power does NOT necessarily increase in a supercritical reactor.

36. Power does NOT necessarily decrease in a subcritical reactor.

37. Power change during ongoing reactivity change is NOT insignificant.

38. Exact criticality is NOT a recognized reactor condition.

39. The reactor is NOT critical at the point of power turning.

40. Prompt jump does NOT describe reactor rate behavior.

41. Prompt jump does NOT describe control rod movement.

42. Prompt jump in power does NOT occur except for step reactivity change.

43. Power response does NOT exhibit a step change.

44. The Reactor Operator does NOT add reactivity to the core.

45. Control rod position change does NOT add reactivity to the core.

46. Integral control rod worth does NOT represent (delta-k/k).

47. Differential control rod worth does NOT represent (delta-k/k)/in.

48. Moderator temperature change does NOT add reactivity to the core.

49. The temperature coefficient does NOT represent (delta-k/k)/°F_mod

50. Fuel temperature change does NOT add reactivity to the core.

51. The Doppler coefficient does NOT represent (delta-k/k)/°F_fuel

52. Xenon change does NOT add reactivity to the core.

53. Xenon worth does NOT represent (delta-k/k).

54. Xenon is NOT a major fission product poison because of cross section alone.

55. Peak xenon buildup is NOT due to iodine decay.

56. Void fraction change does NOT add reactivity to the core.

57. The void coefficient does NOT represent (delta-k/k)/% voids.

58. The power coefficient does NOT represent (delta-k/k)/% power.

59. "Control rod worth" does NOT have meaning.

60. Integral rod worth is NOT based on change from a reference position.

61. Control rod density is NOT the percentage of control rods inserted.

62. Boron worth is NOT represented by (delta-k/k)/ppm.

63. Reactor startups do NOT employ equal reactivity withdrawal increments.

64. The Point-Of-Adding-Heat does NOT ensure automatic criticality.