ML081050294

Oregon State University Triga Reactor, Request for Additional Information, Amendment Request for Reactor Conversion

ML081050294
Person / Time
Site:	Oregon State University
Issue date:	04/22/2008
From:	Alexander Adams NRC/NRR/ADRA/DPR/PRTA
To:	Reese S Oregon State University
ADAMS A, NRC/NRR/ADRA/DPR/PRTA 415-1127
References
TAC MD7360
Download: ML081050294 (9)

Text

April 22, 2008 Steven R. Reese, Director Radiation Center Oregon State University 100 Radiation Center Corvallis, Oregon 97331-5903

SUBJECT:

OREGON STATE UNIVERSITY C REQUEST FOR ADDITIONAL INFORMATION RE: AMENDMENT REQUEST FOR REACTOR CONVERSION (TAC NO. MD7360)

Dear Dr. Reese:

We are continuing our review of your amendment request for Amended Facility Operating License No. R-106 for the Oregon State University TRIGA Reactor which you submitted on November 6, 2007, as supplemented on February 11, 2008. During our review of your amendment request, questions have arisen for which we require additional information and clarification. Please provide responses to the enclosed request for additional information within 60 days of the date of this letter. In accordance with 10 CFR 50.30(b), your response must be executed in a signed original under oath or affirmation. Following receipt of the additional information, we will continue our evaluation of your amendment request.

If you have any questions regarding this review, please contact me at (301) 415-1127.

Sincerely,

/RA/

Alexander Adams, Jr., Senior Project Manager Research and Test Reactors Branch A Division of Policy and Rulemaking Office of Nuclear Reactor Regulation Docket No. 50-243

Enclosure:

As stated cc w/enclosure:

See next page

ML081050294 OFFICE PRTA:LA PRTA:PM PRTA:SC NAME EHylton egh AAdams aa DCollins dsc DATE 4/22/08 4/22/08 4/22/08 Oregon State University Docket No. 50-243 cc:

Mayor of the City of Corvallis Corvallis, OR 97331 David Stewart-Smith Oregon Office of Energy 625 Marion Street, N.E.

Salem, OR 97310 Dr. John Cassady, Vice President for Research Oregon State University Administrative Services Bldg., Room A-312 Corvallis, OR 97331-5904 Mr. Todd Keller Reactor Administrator Oregon State University Radiation Center, A-100 Corvallis, OR 97331-5903 Dr. Todd Palmer, Chairman Reactor Operations Committee Oregon State University Radiation Center, A-100 Corvallis, OR 97331-5904 Test, Research, and Training Reactor Newsletter University of Florida 202 Nuclear Sciences Center Gainesville, FL 32611 Eric C Woolstenhulme Idaho National Laboratory P.O. Box 1625, Idaho Falls, ID 83415-3740

REQUEST FOR ADDITIONAL INFORMATION OREGON STATE UNIVERSITY TRIGA REACTOR DOCKET NO. 50-243 The purpose of the following questions is to determine compliance with 10 CFR 50.64.

1. Section 1.1. Your application states that the aluminum clad graphite reflector elements will be replaced with stainless steel clad graphite elements and that the annular reflector assembly may be replaced with a new annular reflector. Are these changes being made as part of the conversion? If so, please provide justification.

2. Section 4.2. Please provide engineering diagrams and specifications for the fuel. Please describe the quality assurance process for production of the fuel. Are there any quality assurance tests that Oregon State will apply upon receipt of the fuel? If yes, please briefly describe.

3. Section 4.2.1. Please add a discussion of ZrHx composition in the section on fuel.

4. Section 4.2.1. Please specify the composition of the inner region of the fuel rod.

5. Section 4.5.1, Figure 4-3. The figure might be better interpreted by having arrows on Figure 4-2 showing the sectioning. The figure does not appear to be at the core midplane as stated. Please clarify.

6. Section 4.5.1, Figure 4-10 and Section 4.5.2, Figure 4-16. Why doesnt the calculated BOL excess reactivity equal $7.10 as quoted on page 15 for the HEU core and $5.48 as quoted on page 29 for the LEU core?

7. Section 4.5.1, Figures 4-6 to 4-9. It would help in interpreting these figures, and Table 4-5, if experimental errors were shown (assuming they are large enough to be visible).

8. Section 4.5.1. Was the segmentation of the fuel rods for the depletion analysis done for each rod individually or for an average rod?

9. Section 4.5.1. The HEU core is analyzed assuming operation at constant power. Have any calculations been done with the actual operating history to see what the effect of this assumption is on key parameters? If so, what was the impact?

10. Section 4.5.1. Were any data (like excess reactivity or control rod worth) available at other than BOL to use to benchmark the neutronic model for the HEU core? If so, why werent they used?

11. Section 4.5.1, Figure 4-9 and Table 4-5. Why does the calculated transient rod worth deviate from the measurement for the HEU core at BOL while the other three control rods showed much closer agreement between calculated and measured worth?

12. Section 4.5.1. Differences in bulk pool temperature appear in the SAR. On Page 19, Section 4.5.1, Depletion analysis was conducted at 50 degrees C. On Page 24, Section 4.5.1, RELAP analysis was conducted at 49 degrees C. On Page 19, Section 4.5.2, Depletion analysis was conducted at 50 degrees C. On Page 39, Section 4.7, T/H analysis

was conducted at 49 degrees C. On Page 39, Section 4.7, OSU TS limit pool temperature to maximum of 49 degrees C. How do these differences in temperature impact the results of the calculations?

13. Section 4.5.1, page 18. Please elaborate on the aspects of the evaluation techniques that contribute to the discrepancy between the measured and calculated shutdown margin for the HEU BOL core when the regulating rod is fully withdrawn. How does the calculated shutdown margin compare with the measured value for the other control rods?

14. Section 4.5.1, Table 4-7 and Section 4.5.2, Table 4-14. Please justify the use of two points to extrapolate to zero boron concentration in the algorithm for calculating neutron lifetime.

15. Section 4.5.1, page 24. The prompt neutron lifetime is usually written as lp in the SAR but on page 24 it appears that the symbol is used. Please confirm.

16. Section 4.5.1. A measurement was done for the reactivity worth of an irradiation facility placed in the B-1 grid position. Have you calculated this worth and if so, what is the value?

17. Section 4.5.1 and 4.5.2. The void coefficients and moderator coefficients are assumed to have been calculated at BOL. Are there any changes to the differences from HEU to LEU if MOL or EOL is considered?

18. Section 4.5.1 and 4.5.2. On pages 23 and 36 it says a reactivity loss was observed. This implies a measurement although the text is referring to a calculation. Please clarify.

19. Section 4.5.2, page 33. Does the shutdown margin requirement take into account the reactivity added by irradiation facilities and experiments in place and the total worth of all non-secured experiments in their most reactive state and the core in the reference condition? Is the most reactive control rod fully-withdrawn?

20. Section 4.7.2, Table 4-21. The analysis for the HEU core uses 84 fuel rods in the core although it appears from Figure 4-4 and Table 4-1 that there should be 85 rods present with control rods withdrawn. Please explain the difference.

21. Section 4.7.2, Table 4-21. What is the effect on power peaking of replacing a burnt fuel rod (e.g., an IFE) with a fresh fuel rod? What controls are in place with respect to loading new fuel? Provide a calculation to indicate the change in the peaking factor when fresh fuel is placed in an EOL core at the worst location.

22. Section 4.7.2. RELAP5 had a fundamental error in the point kinetics model that has recently been fixed. Which version of the code was used for the analysis in the SAR?

Please verify that your model is giving results consistent with the transient (e.g., by checking results as a function of time step or with another stand-alone point kinetics model).

23. Section 4.7.2. Please provide Reference 14 in order to justify the pressure loss coefficients used in the RELAP5 analyses.

24. Section 4.7.2. Please provide analytical justification for ignoring cross flow between neighboring flow channels.

25. Section 4.7.2, Figure 4-24. Should the bottom of the end fitting align with the top of the grid plate (to be consistent with Eq. 4.5) or the bottom (as shown in Fig. 4-24)?

26. Section 4.7.2, Table 4-20. Could the coordinate for the Outer Gap (Node Number 23 in Table 4-20) be in error? In reference to Figure 4-26, the value listed in Table 4-20 (0.01785-0.01786 m) implies the clad is actually closing in on the fuel and there is practically no gap.

27. Section 4.7.2. Was the transient rod also removed for the calculation of the rod power distribution in the core?

28. Sections 4.5.8, 4.7.3, and 4.8.3. Does the peak power density (maximum local heat flux) at steady-state occur in the fuel element (rod) with the maximum rod power?

29. Section 4.7.2 Table 4-21. What is the significance of the Effective Peak Factor (EPF) in relation to the peak fuel temperature and the minimum DNBR? It does not appear that the EPF has a direct relation to the heat flux at the clad surface.

30. Section 4.7.2. Please correct the citation for Reference 18, the 2006 CHF Look-up table.

31. Section 4.7.2. Please provide reference(s) for the correction factors, the Ks, and explain their specific adaptation for the OSTR geometry and operating conditions. Are there additional correction factors that go with the most recent (2006) Look-up table?

32. Section 4.7.2. Why did the thermal analysis not use the Groeneveld Look-up table built into RELAP5-3D?

33. Section 4.7.2, Table 4-18. In accordance with the subchannel shown in Figure 4-23, a consistent definition for the heated diameter should be the heated perimeter divided by pi.

That is the definition adopted by Bernath for his CHF correlation. In the conversion SAR, what was the heated diameter used in the Bernath correlation?

34. Section 4.7.4, Figure 4-30. Are there any contributors to the change in axial power profile with burnup other than burnup (e.g., control rod movement)?

35. Section 4.7.4. The text stated that there are 84 FLIP fuel elements in the initial HEU core including the three control rod fuel followers. However Figures 4-27, 4-28, and 4-29 indicate that there are 85 fuel elements. What is the correct number of fuel elements assumed in the RELAP5-3D model of the OSTR?

36. Section 4.7.4 and Table 4-21. What is the number of HEU fuel elements assumed in calculating the hot rod peak factors for the HEU core in Table 4-21?

37. Section 4.7.4. Are changes in gap properties (e.g., gap size, oxidation at the fuel boundary, gas composition) over time taken into account when calculating fuel temperatures? Also is a gap of 0.1 mills assumed for the LEU cores?

38. Section 4.7.5. What reactivity feedback mechanisms other than Doppler are included in the RELAP5 model?

39. Section 4.7.5. Were core average thermal-hydraulic parameters (e.g. hydraulic diameter and heated diameter) used in the representation of the average channel?

40. Section 4.7.5. How were core-average properties (e.g. coolant temperature and fuel temperature) determined for use in calculating reactivity feedbacks?

41. Section 4.7.5. Does the pulsing of the transient rod result in a change in the location of the hot rod in the B Ring?

42. Section 4.7.5. In order to better understand the comparison of the measured temperature with the IFE reading it is necessary to know the location of the IFE. Please provide.

43. Section 4.7.7. Figure 4-59. Where are the locations of the parameters plotted in Figure 4-59?

44. Figure 4-61. It appears that the data for the outer cladding temperature and the bulk coolant temperature are reversed. Please comment.

45. Section 4.7.8. Please verify that reference to BOL instead of MOL in several places in this section is a typographical error.

46. Section 4.7.9. Please verify that reference to BOL and Middle of Life instead of EOL in several places in this section is a typographical error.

47. Figure 4-74. The figure is missing labels for the two vertical axes.

48. Section 4.7.10, Figure 4-80. Please note that the legend is incomplete in the pdf version.

49. Sections 12.2 and 12.4. Do you want the changes to procedures and to the emergency plan to be made as part of the conversion order or do you plan to follow your technical specification (TS) requirements for procedures changes and 10 CFR 50.54(q) for emergency plan changes. If you want to make these changes as part of the conversion order please submit the changes.

50. Section 12.5. If you plan to make any changes to the physical security plan as part of the conversion order, please submit the changes.

51. Section 13.2.1. Explain the differences in FLIP reactor room air activity without water between the license renewal SAR and the conversion SAR.

52. Section 13.2.2. How much reactivity is inserted by the flooding of a beam port?

53. Have the consequences of pulsing the reactor from full power operation been considered?

If yes, what are the results; if no, why not?

54. Section 13.2.3. What is the maximum calculated temperature for the OSTR LOCA and the acceptance criterion?

55. Section 14. Please identify and specifically justify the changes that were made to the TSs.

56. Section 14.2.1. Please confirm that the ratio of hydrogen to zirconium will not change so that the limiting temperature remains the same upon conversion.

57. Section 14.5.3.1(b). It appears that you are proposing that this TS be changed from a shall statement to a may statement. Please explain why this change is needed as part of the conversion process or request this change as part of your license renewal application.

58. Section 15.2. Your proposed changes to license condition 2.b(2) do not contain authority to possess the AGN core. If you desire to remove this part of the license condition an application should be made by the normal license amendment process. If not, please propose changes to your proposed license condition as appropriate. Your proposed license conditions after conversion will not allow receipt, possession or use of any HEU.

Will you need to possess any HEU (e.g., fission chambers and flux foils) after conversion?

If so, please propose and justify appropriate license conditions. Your proposed license condition contains the authority to possess, but not separate, such special nuclear material as may be produced by the operation of the facility. Does this part of your proposed license condition duplicate license condition 2.b(4)? If so, is it needed?

59. Section 15.2. Your proposed license condition 2.b(5) for possession of the HEU fuel until it is removed from the facility allows receipt of uranium-235. Please confirm that no additional HEU will be received and that the HEU possessed under this license condition will not be used. Please amend your proposed license condition.

60. Appendix A. Describe in greater detail startup tests planned for pulsed operation.

61. Appendix B. What action is taken if an acceptance criterion for a startup test is not met?