ML18228A811
| ML18228A811 | |
| Person / Time | |
|---|---|
| Issue date: | 12/31/2018 |
| From: | Office of Nuclear Regulatory Research |
| To: | |
| Karagiannis H | |
| Shared Package | |
| ML18228A729 | List: |
| References | |
| RG 3.54 DG-3050 | |
| Download: ML18228A811 (6) | |
Text
Response to Public Comments on Draft Regulatory Guide DG-3050, Spent Fuel Heat Generation in an Independent Spent Fuel Storage Installation Proposed Revision 2 of Regulatory Guide 3.54 On December 23, 2016, the U.S. Nuclear Regulatory Commission (NRC) published a notice in the Federal Register (81 FR 94431) announcing that Draft Regulatory Guide DG-3050 (proposed Revision 2 of Regulatory Guide 3.54) was available for public comment.
The public comment period closed on February 21, 2017 and the NRC staff received comments from the individuals and organizations listed below. The following Table documents the public comments and NRC staffs responses. The received comment documents are available in the Agencywide Document Access and Management System (ADAMS) under the indicated accession numbers below.
The NRC staff received comments from the following:
Mr. David Cullison, NRC Clearance Mr. MyeongSoo Lee Mr. John Garza Officer, Customer Service Division, email: fiatluxkr@khnp.co.kr, Address:
Office of the Chief Information Officer, South Korea VC Summer Nuclear Station Unit l NRC, e-mail: DavidCullison@nrc.gov Dated: December 23, 2016 Jenkinsville, SC, 29065 U.S. Nuclear Regulatory Commission ADAMS Accession No.: ML17048A161 Email: jgarza@scana.com 11545 Rockville Pike, Rockville, MD Dated: December 12, 2017 20852, Dated: January 13, 2017 ADAMS Accession No.: ML18052A049 ADAMS Accession No.: ML18052A048 Mr. Justin T. Wheat Mr. Jesse J. Klingensmith Nuclear Licensing Manager Westinghouse Electric Company Southern Nuclear Operating Company Address: Cranberry Township, PA (SNC) Email: jtwheat@southernco.com Email: klingejj@westinghouse.com Dated: February 21, 2017 Dated: June 27, 2017 ADAMS Accession No.: ML18052A050 ADAMS Accession No.: ML18219B840 No. Commenter Comment NRC Resolution 1 Mr. David Cullison, Revised link to access Nuclear Fuel Data. The NRC staff agreed with the comment and the NRC paragraph of interest was changed as follows:
We had noticed that the subject document, U.S.
Department of Energy (DOE) Form GC-859, Figure 2 illustrates the range of application of the NUCLEAR FUEL DATA SURVEY FORM GC-859 at guide and compares it with the existing and https://www.eia.gov/survey/form/gc_859/form.pdf. projected commercial spent fuel inventory of the had expired prior to publication of the guide. United States, as published in NUREG/CR-7227 (ORNL/TM-2015/619), US Commercial Spent Nuclear Fuel Assembly Characteristics: 1968-2013, issued September 2016.
Response to Public Comments on Draft Regulatory Guide (DG)-3050, Rev. 2 No. Commenter Comment NRC Resolution 2 Mr. MyeongSoo Revise the calculation method on Appendix A of the The NRC staff agreed with the comment to Lee DG-3050. display the values in the RG Tables in a scientific South Korea format. The Tables were changed to reflect this Also, it is recommended that 1) all of the values in change.
Appendix A sample calculation should be displayed in scientific format for user support, and 2) the total Also, the NRC staff agrees that the total power power fraction of each isotopes for each cycle should for each fraction should be 1. The RG in section be one (1). So it is recommended that the guide C.1.1 was changed to state: The user should describe the notice as following. ensure that the fuel burnup obtained from the time-integrated specific power of the histogram in "If the total power fraction of each cycle is less than Figure 1 equals the actual burnup of the fuel.
the one (1), add some value for the U235 isotope to The user should also ensure that the sum of make the total power fraction is one (1). relative power fractions Si/S for each irradiation interval should be 1 (because of interpolation error). In this case, the user should increase the power fraction of U-235 to preserve the correct total operating power for the interval.
3 Mr. John Garza Clarify whether Rev. 1 to RG 3.54 is being The NRC staff agreed with the comment.
VC Summer superseded by Rev. 2. Rev. 1 methodology should Revision 1 to RG 3.54 is superseded by Revision Nuclear Station remain an acceptable method, but the draft Rev. 2 2.
Unit l implies that Rev. 1 is being superseded.
Jenkinsville, SC, Current licensees may continue to use guidance 29065 the NRC found acceptable for complying with the identified regulations (e.g., RG 3.54 Revision 1) as long as their current licensing basis remains unchanged. For new applications, Revision 2 is an acceptable methodology, but use of Revision 1 could also be used if justified.
4 Mr. John Garza Rev. 2 methodology seems to be largely based on The NRC staff partially agreed with the comment.
VC Summer ANS-5.1-2005 and/or ANS-5.1-2014. If that is correct, The NRC licensees do not have to separately Nuclear Station then ANS will have to be compensated for publishing review the ANSI/ANS 5.1-2014 standard since Unit l their standard in a publicly-available document. the staff obtained permission from ANS to use 9 Jenkinsville, SC, coefficients from the standard as reflected in the 29065 Instead, Rev. 2 could just endorse the ANS standard RG. Therefore, instead of using the 23 as an acceptable option (while not re-publishing the coefficients listed in DG-3050, the final RG 3.54 uses only 9 coefficients (see Section C.1.1, 2
Response to Public Comments on Draft Regulatory Guide (DG)-3050, Rev. 2 No. Commenter Comment NRC Resolution details of the ANS standard), while retaining the Rev. Table 1). This reduction of the number of 1 methodology as another acceptable option. coefficients from 23 to 9 as listed in Table 1 does not alter the calculations for fission products.
Section C.1.1 reflects the change.
5 Mr. Justin T. Wheat In Appendix A, Section A.1.4, Page A-3: The NRC staff agreed with the comment.
Southern Nuclear is incorrectly reported as 1.848 x 10-2 W/kgU in The typo was corrected in Table A-5 in Appendix Operating Table A.5 A to RG 3.54 to read: as 1.848 x 10-1 W/kgU.
Company (SNC) 6 Mr. Justin T. Wheat Section C.1.2.2, Page 12: The NRC staff agreed with the comment.
Southern Nuclear The third and final condition for values of H(t) to be Section C.1.2.2 has been changed to read: The Operating conservative is: power density, in units of kilowatts per kilogram Company (SNC) of uranium, is greater than 5 times the
The power density, in units of kilowatts per kilogram enrichment in wt% U-235."
of uranium, is less than 5 times the enrichment in wt%
U-235." This change now covers the relevant parameter ranges given in Table 7 for enrichment and This does not cover the relevant parameter ranges average power density [2 Es < 5 and 12 given in Table 7 for enrichment and average power Savg 50].
density [2 Es < 5 and 12 Savg 50]. Assembly C-64, the subject of Appendix A's sample calculation, does not meet the aforementioned condition either.
7 Mr. Justin T. Wheat Section. C.1.1, Page 6: The NRC staff agreed with the comment and Southern Nuclear The 23-group coefficients aij and ij of Equation 3 are corrected the typo. The 23-group coefficients Operating referred to in the text as "aij" and "Aij rather than with changed in Section C.1.1 as suggested by the Company (SNC) the i and j indices as subscripts commenter.
8 Mr. Justin T. Wheat Section C.1.2.1, Page 11-12: The NRC staff agreed with the comment. The Southern Nuclear K is defined as being dependent on the average subscript "k" was applied to the specific power S Operating specific power (Savg) in Equation 11. Based on the in the equation. The other uses of the variable Company (SNC) usage of K in Equation 9, it would make more sense should be verified to be consistent. The equation to define it based on SK #11 was changed as a result of this comment.
Change Equation 11 to be the following:
K = (Sk/) x 2.58 x 1010 3
Response to Public Comments on Draft Regulatory Guide (DG)-3050, Rev. 2 No. Commenter Comment NRC Resolution 9 Mr. Justin T. Wheat Section C.1.2.1, Page 12: The NRC staff agreed with the comment. Use of Southern Nuclear Savg is defined in 'Equation 7 as the average specific a similar variable for different parameters may Operating power over the entire operating history of the fuel, but cause confusion in the implementation. The Company (SNC) later in Equation 11 as the specific power density. absolute power (MW) will be modified to use This repeated elsewhere in the variable P and specific power (MW/MTU) will use document. S. The equation #12 (DG-3050 Equation 11) was changed as a result of this comment.
Be consistent in the definition of Savg, whether it be using both specific power and specific power density as the definitions or choosing only one to use.
10 Mr. Justin T. Wheat Section C.1.3, Page 14: The NRC staff agreed with the comment. The Southern Nuclear The actinide coefficient n is written as "n": typo in Section C.1.3 was corrected.
Operating Correct it to n Company (SNC) 11 Mr. Justin T. Wheat Section C.1.1: The NRC staff agreed with the comment. Section Southern Nuclear Explicitly defining as Sik=Sk *Si/S would make this C.1.1 was corrected.
Operating section more clear.
Company (SNC) 12 Mr. Justin T. Wheat Section C.1.4, Page 16: The NRC staff agreed with the comment. The Southern Nuclear Equation 6, is written with an extra parenthesis: typo in Section C.1.4 was corrected. This is listed Operating Ps(t, T) = A(t)PF((t, T) as equation 17 in the final RG 3.54.
Company (SNC) Remove the extra parenthesis from the equation 13 Mr. Justin T. Wheat In Section C.1.2.1: The NRC staff disagreed with the comment.
Southern Nuclear The statement When applied to BWR fuel, they yield Currently the DG does not distinguish between Operating conservative results" suggests that the overall PWR and BWR designs for the factor Fs. Indeed, Company (SNC) conservatism for BWR (vs PWR) is increased due to it results in some conservatism for BWR designs.
the use of the PWR fuel spectrum. How does this The amount of conservatism is nominally 1-5%.
compare.to the Correction Factors computed with Expanding the factors to account explicitly for Table 4? BWRs could be addressed, however the factor is very dependent on the void fraction and under Perhaps Fs could be redefined for PWR *and BWR high void fractions this factor approaches the separately to yield more accurate results for BWR. value for PWR. No change was made to the RG as a result of this comment.
4
Response to Public Comments on Draft Regulatory Guide (DG)-3050, Rev. 2 No. Commenter Comment NRC Resolution 14 Mr. Justin T. Wheat In Appendix A: The NRC staff disagreed with the comment.
Southern Nuclear Adding some more input parameters with the Additional examples could potentially be Operating corresponding output -decay heats would be very confusing. No change was made to the RG as a Company (SNC) beneficial in qualifying in-house implementations. result of this comment.
Suggest an example I/O table for both PWR and BWR.
In Section C.1.1, Page 8: The NRC staff agreed with the comment. This
The user should also ensure that the sum of relative comment was addressed in an earlier comment Mr. Justin T. Wheat power fractions S/S for each irradiation interval is not (No. 2 of this Table on responses to public Southern Nuclear less than unity (because of interpolation error)" comments) from KHNP, Korea. As noted in the 15 Operating In the case of interpolation error, how should NUREG/CR, the fission rates should be Company (SNC) interpolation be handled? Are there severely non- normalized to unity by assuming U-235 fissions.
linear regions of Table 3 that should be interpolated differently?
16 Mr. Justin T. Wheat In Section C.2, Page 18: The NRC staff agreed with the comment, but no Southern Nuclear The applicability of SS clad fuel is mentioned, what change to the document is necessary. The Operating about the applicability of SS dummy rods? An applicability of the standard did not consider the Company (SNC assembly average Cobalt concentration could be use of stainless steel rods and contribution of specified so the user can determine if a non-standard decay heat from their cobalt content. Applicants assembly is applicable. can, however, address cobalt content as part of their application. As stated in Section C.2, An assembly parameter that may restrict application of the guide is the cobalt 59 (Co-59) content of the clad and structural materials.
In cases where this is a concern, the condition can be addressed relatively easily by the applicant. Defining the limiting cobalt content for an assembly as part of the application, including the extra calculations that would be needed to calculate additional heat to confirm the value. No change was made to the RG as a result of this comment.
17 Jesse J. In Section A.1.4 states that [a] small correction factor The NRC staff agreed with the comment.
Klingensmith of 0.989 Using an input average power of 24.96 5
Response to Public Comments on Draft Regulatory Guide (DG)-3050, Rev. 2 No. Commenter Comment NRC Resolution Westinghouse kW/kgU, we are calculating a correction factor of A change was made in Section A.1.4 of the RG Electric Company 0.991 using the second term in Equation 15: to change the value of 0.0989 to 0.9914.
. .
1.82 1.82 24958 = 0.9914 6