ML18169A253

DG-3053 (Rg 3.71) Responses to Public Comments

ML18169A253
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Issue date:	09/30/2018
From:	Office of Nuclear Regulatory Research
To:	Office of Administration
Karagiannis H
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ML18169A251	List: ML18169A253 Regulatory Guide 3.71
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DG-3053, RG-3.71
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Responses to Public Comments on Draft Regulatory Guide DG-3053, Nuclear Criticality Safety Standards for Nuclear Materials Outside Reactor Cores Proposed Revision 3 of Regulatory Guide 3.71 On August 24, 2017, the U.S. Nuclear Regulatory Commission (NRC) published a notice in the Federal Register (82 FR 40173) announcing that Draft Regulatory Guide DG-3053 (proposed Revision 3 of Regulatory Guide 3.71) was available for public comment.

The comment period closed on October 23, 2017 and the NRC received six comment submissions. The comments have been edited for clarity. The following table documents the public comments and NRC staffs responses.

The NRC received comments from the following:

Mr. Lon Paulson Mr. Daniel Cronin Mr. Ronald Lavera

<Lon.Paulson@ge.com> <dcronin@ufl.edu> <Ronald.LaVera@nrc.gov>

GE-Hitachi/Global Nuclear Fuel - University of Florida Training Reactor U.S. Nuclear Regulatory Commission Americas 202 Nuclear Science Building Mail Stop O-7D21 3901 Castle Hayne Road, K26 P.O. Box 118300 Washington, DC 20555 Wilmington, NC 28404 Gainesville, FL 32611-8300 Dated: August 30, 2017 Dated: August 23, 2017 Dated: August 24, 2017 ADAMS Accession No.:

ADAMS Accession No.: ADAMS Accession No.: ML18071A045 ML17352A513 ML17242A021 Mr. David Erickson Ms. Patricia Schroeder Mr. Nima Ashkeboussi

<david.erickson@srs.gov> <pschroeder@ans.org> <nxa@nei.org>

Savannah River Site American Nuclear Society Nuclear Energy Institute 707-C, Rm 228 555 N. Kensington Ave. 1201 F Street, NW, Suite 1100 Aiken, SC 29808 La Grange Park, IL 60561 Washington, DC 20004 Dated: September 27, 2017 Dated: October 11, 2017 Dated: October 23, 2017 ADAMS Accession No.: ADAMS Accession No.: ADAMS Accession No.:

ML17276A315 ML17290A355 ML17304A064

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution 1 Lon Paulson, The following citations are incorrect: The NRC staff agrees with the comment and the GE-Hitachi/Global Section C.1 of RG 3.71: references have been updated accordingly.

Nuclear Fuel - a. ANS-8.12 should be reaffirmed (R) 2016.

Americas b. ANS-8.14 should be R2016.

c. ANS-8.20 should be R2015.

d. ANS-8.22 should be R2016.

e. ANS-8.26 should be R2016.

Section C.2 of RG 3.71:

f. ANS-8.17 should be R2014.

2 Lon Paulson, The clarification regarding Section 4.1 of ANSI/ANS- The NRC staff disagrees with the comment. Section GE-Hitachi/Global 8.24-2007 is unnecessary and unwarranted. There is no 5.4.3.1.7.1(B)(3) of NUREG-1520 states that in addition Nuclear Fuel - need for annual reverification. The computer code to initial verification, licensees should periodically re-Americas system is verified prior to first use; the clarification might verify calculational methods. This is appropriate to emphasize the importance of verification prior to first use ensure that inadvertent changes have not been made to to confirm proper functionality of the code system. either the hardware or software that would invalidate the results of the validation. No change will be made for this comment. Note: ANSI/ANS-8.24-2007 has been superseded by ANSI/ANS-8.24-2017 which was issued in December 2017 and the Regulatory Guide (RG) has been updated to reflect the 2017 version.

3 Daniel Cronin, The last sentence in the Applicability section should be The NRC staff agrees with the comment. The University of shortened to read: This revision is not intended for use Applicability Section has been modified.

Florida Training by nuclear reactor licensees. The rest of the sentence Reactor is vague and likely to cause confusion. This is needed to be consistent with the statement under Reason for Revision addressing the applicability to reactor facilities licensed under 10 CFR Part 50.

4 Ronald Lavera, The proposed draft guide should address the following The comment is beyond the scope of this RG and no NRC issue: Under the 1979 MOU with DOT, NRC regulations change will be made to the RG.

do not contain any requirements for Storage in Transit.

Once fuel is delivered to the reactor site, it is no longer in transit, even if it has not yet been placed in the new fuel racks. There is some operating experience indicating 2

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution that some reactor sites have received multiple shipments of new fuel without placing them in approved new fuel racks. 10 CFR Part 71 does not consider criticality controls during Storage in Transit; hence, there are no criticality controls applied when multiple shipments are staged on-site awaiting placement in the new fuel racks.

5 David Erickson, It is not appropriate for NRC to claim that ANS-8.1-2014 The NRC staff agrees in part with the comment.

Savannah River contains an error. The value for the plutonium nitrate However, the staff has determined that the 7.3 g/L Site concentration single parameter limit has been there plutonium nitrate concentration limit in Table 1 of ANS-since 1981 and has a sufficient basis. If the NRC has a 8.1-2014 warrants clarification, in that the modeling of different basis, it can state the value it prefers to use, plutonium nitrate with 100 wt% 239Pu at this with an applicable reference to support. The value concentration would produce a k-eff value above 0.98.

presented is not to be used for normal conditions, but The standard states that the limit is applicable to a only as a bounding value for credible abnormal mixture of isotopes, but no minimum 240Pu content is conditions after accounting for uncertainty. specified. The staff notes that in practice there will always be some 240Pu present, as it is not possible to attain 100% 239Pu. The exception has been removed and replaced with an appropriate clarification.

6 Patricia Schroeder, ANS is an American National Standards Institute (ANSI) The NRC staff agrees with the comment. The RG will be American Nuclear Accredited Standards Developer. Standards approved by revised so the ANSI designation will not be included in Society ANSI are permitted to include the ANSI acronym in the discussion of committees or working groups. It will their designation. ANSI does not approve any of our only be included in the names of standards approved by committees or working groups, so ANSI should not be ANSI.

used in their names. Suggested changes correct the use of the acronym, update the name of the ANS consensus committee responsible for approving NCS standards, and update reaffirmation dates for ANS standards.

7 Patricia Schroeder, Reaffirmation is in process for two additional standards The NRC staff agrees with the comment. The American Nuclear ANS-8.3-1997 (R2012) and ANS-8.5-1996 (R2012). references have been updated accordingly in the final Society ANSI approved of these reaffirmations is expected by the RG.

end of this month or early next month.

8 Nuclear Energy Two of the standards (ANS-8.10 and -8.23) are endorsed The NRC staff disagrees with the comment. In the case Institute with added exceptions. These appear to be imposing of ANSI/ANS-8.10-2015 (issued after the 2010 revision 3

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution new or different staff positions. This is compounded with of Regulatory Guide 3.71), the NRC staff is providing changes made to NUREG-1520, Rev. 2, specifically clarification, and not taking additional exceptions to this Section 5.4.3.1.1. We would also refer to NEIs standard. The clarifications point out that NRC does not comment letter on Rev. 2 of NUREG-1520. require licensees to accept the more conservative approach as described in the standards to meet the regulations. Specifically, this clarification is describing that the standard may be applied if the specified conditions are met in individual areas, rather than for the entire facility as stated in the standard. In addition, the dose limits in 10 CFR 70.61 are higher, and therefore less restrictive, than those in ANSI/ANS-8.10-2015. In both cases, a licensee could acceptably commit to follow the standard.

With regard to ANSI/ANS-8.23-2007 (R2012), the NRC staff is also providing clarification to point out that compliance with the standard does not require compliance with ANSI N13.3-1969 (R1981), which is now obsolete. As with ANSI/ANS-8.10, a licensee could acceptably commit to follow the standard in full.

The staff previously reviewed NEIs letter on Rev. 2 of NUREG-1520, dated November 3, 2014, and subsequently addressed all public comments on NUREG-1520 as appropriate. Section 5.4.3.1.1 of NUREG-1520 was revised to refer to the most current revision of the standards that have been endorsed by the NRC in the version of RG-3.71 in effect when the license application was submitted. This ensures consistency between NUREG-1520 and the RG as it is updated to reflect the most recent industry standards.

9 Nuclear Energy The last paragraph of Section D states: If an existing The NRC staff agrees with the comment. The comment Institute licensee voluntarily seeks a license amendment or is correct that if a request is unrelated to the topics of this changethen the staff may request that the licensee 4

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution either follow the guidance in this regulatory guide or RG, then the applicant will not be asked to address this provide an equivalent alternative process that RG.

demonstrates compliance with the underlying NRC regulatory requirements. This is not considered If an existing licensees voluntary request involves a backfitting. It would be helpful to gain additional regulatory issue directly relevant to this RG and is an context from NRC staff as to what level of justification essential consideration in the staffs determination, then would be required. Additionally, it is the industrys the level of justification required to demonstrate that an understanding that, pursuant to the NRCs current alternative to this RG complies with the underlying position regarding forward-fitting that the application of regulatory requirements will vary based on the nature Rev. 3 would fall outside the definition of backfitting only and safety significance of the alternative and based on where it (1) relates to a licensees voluntary request, and the degree of difference from the standards endorsed by (2) is an essential consideration in the NRC staffs this RG.

determination of the acceptability of the licensees voluntary request. It is our understanding that unrelated As the comment notes, applicants would only be asked licensing actions or amendments should not garner new to follow this RG or justify an alternative when two commitments regarding the new referenced standards in factors are met: (1) the NRC staffs consideration of the Rev 3, nor should they garner subsequent RAIs related request involves a regulatory issue directly relevant to to criticality safety, as discussed in the September 26, this regulatory guide, and (2) the specific subject matter 2017 public meeting. of this regulatory guide is an essential consideration in the staffs determination of the acceptability of the licensees request. Similar language was included in Revision 2. No changes were made as a result of this comment.

10 Nuclear Energy The last sentence on page 11 states: This is not The NRC staff agrees that Section D, Implementation, Institute considered backfitting as defined in 10 CFR 70.76 or 10 does not specifically address implementation in license CFR 72.62. This notes that license amendments or renewals under 10 CFR 70.73. Requests for license changes would not constitute a backfit, but is silent on renewal under 10 CFR 70.73 are voluntary requests for license renewal. This leaves considerable uncertainty as new approvals from the NRC and, therefore, subject to to NRCs expectations during license renewal. An the language referenced in the comment, stating:

attempt to endorse a particular standards current version may be problematic during a Part 70 license If an existing licensee voluntarily seeks a license renewal given that several decades may pass between amendment or change and (1) the NRC staffs renewals. This places an unnecessary burden on a consideration of the request involves a regulatory issue licensee to perform a gap analysis, demonstrate or justify directly relevant to this regulatory guide and (2) the 5

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution exceptions to revised standards, or potentially make specific subject matter of this regulatory guide is an significant licensed program upgrades. essential consideration in the staffs determination of the acceptability of the licensees request, then the staff may request that the licensee either follow the guidance in this regulatory guide or provide an equivalent alternative process that demonstrates compliance with the underlying NRC regulatory requirements. This is not considered backfitting as defined in 10 CFR 70.76 or 10 CFR 72.62.

The NRC staff does not agree that requesting applicants for license renewals to address this RG imposes an unnecessary burden. This RG addresses standards for preventing nuclear criticality, a key feature of safely handling special nuclear material. The NRC staff does not deem it an unnecessary burden at the time of license renewal to ask licensees to adopt up-to-date standards for such a significant safety issue or to justify how they will otherwise comply with the underlying NRC regulations in order to permit licensed activities for an additional ten to twenty years. No changes were made as a result of this comment.

11 Nuclear Energy The applicability of the draft guide is also proposed to be The NRC staff disagrees with this comment.

Institute expanded to include 10 CFR Part 71. This could impart Compliance with an RG is not required and compliance unintended burdens on certificate holders when renewal with the standards in this RG is voluntary. The RG is pursued, without a clear regulatory basis, articulated provides one method of demonstrating compliance with benefit, or safety concern. This appears to be imposing the underlying NRC regulations. Other methods may a staff position that is either new or different from a also be acceptable. Additionally, backfit and issue previous staff position. In addition, the requirements of finality considerations do not apply to licensees and 10 CFR 71.55 and RG 7.9 have not changed and there applicants under 10 CFR Part 71.See response to is no equivalent Use of Industry Standard statement Comment 9. No changes were made as a result of this (similar to Section 5.4.3.1.1 in NUREG-1520, Rev. 2) for comment.

Part 71 fissile package reviews. Therefore, it is unclear 6

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution how NRC plans to expand the applicability of the draft guide to Part 71 reviews.

12 Nuclear Energy The draft guide endorses and harmonizes both ANS and The NRC staff agrees in part with the comment and a Institute ISO standards. This is misplaced as an NRC goal; statement has been added in Section C of the RG to consideration should be given to removal of the ISO clarify that either ANSI/ANS8.3 or ISO 7753 may be standard. Should ISO standards remain, the draft guide used as an acceptable method to meet the regulations.

should address the acceptability of a licensee using a combination of both standards. For example, a licensee could apply all ANS standards except ANS-8.3, and alternatively apply ISO 7753. Otherwise without further clarification, endorsing two different standards for criticality accident alarm systems could cause confusion as to which takes precedent.

13 Nuclear Energy As stated in the FRN, the proposed revision would The staff agrees, and alternatives may be used. See Institute provide methods that are acceptable to the NRC staff. also the response to Comment 9. No changes were The draft guide incorporates several shall statements, made as a result of this comment.

understood to denote requirements of the standard, if and only if the licensee commits to that particular standard. Alternately, if the standard is not accepted by the licensee, and the licensee chooses an alternate method, shall statements would not apply.

14 Nuclear Energy As noted during the September 26, 2017 public meeting, The NRC staff agrees in part with the comment. The Institute ANS standards are continually being revised and staff disagrees with the statement that endorsing the reaffirmed approximately every 5 years. However, this is current version of the 18 standards is not practical. The problematic in that the effective dates of issuance are NRC currently has a policy of reviewing RGs every 10 frequently changing and endorsing the current versions years. It is the policy of NRC to endorse, to the extent of the 18 standards is not practical. For example, practical and consistent with regulations, the most recent several standards listed in Section c.1 are already version of industry consensus standards. Standards are outdated and have the following errors: constantly being reviewed and revised, and current

i. ANS-8.12 should be R2016 practice is to keep up with them on at least a ten-year ii. ANS-8.14 should be R2016 review cycle.

iii. ANS-8.17 should be R2014 iv. ANS-8.20 should be R2015 7

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution

v. ANS-8.22 should be R2016 The reaffirmation dates of the standards have been vi. ANS-8.26 should be R2016 updated. The staff notes that reaffirmation does not We also recommend a minimum of 5 years between change the content of the standard, so would not be a revisions, in recognition of the Cumulative Effects of reason (by itself) to revise the RG.

Regulation.

15 Nuclear Energy Section c.2.b, paragraph 2, states Section 4.2.2 of the The NRC staff agrees with the comment. The text has Institute standard states that a criticality alarm system is not been corrected.

required in areas where personnel would be subject to an excessive radiation dose. This is an error. It should state where personnel would not be subject to an excessive radiation dose.

16 Nuclear Energy The ANS-8.3 exceptions added the sentence: A The NRC staff disagrees with the comment. The Institute clarification is that 10 CFR 70.24 requires placement of criticality alarm system (CAAS) consists of multiple detectors in areas where threshold quantities of special components, including detectors and annunciators. A nuclear material are present, but that audible or visual CAAS must be deployed wherever the threshold alarms may be located in areas where immediate quantities listed in 10 CFR 70.24 are exceeded. The evacuation is determined to be necessary based on the placement of detectors is in accordance with the dose potential for an excessive dose. ANS-8.3 defines an thresholds indicated [70.24(a), is the applicable excessive radiation dose as a combined neutron and regulation, vs. 70.62(a)(1)]. The placement of gamma dose of at least 12 rad in free air. 10 CFR annunciators (e.g., horns) is based on wherever 70.62(a)(1) requires a monitoring system capable of evacuation is deemed necessary, which may be based detecting an absorbed dose in soft tissue of 20 rad of on the potential for an excessive radiation dose. The combined neutron and gamma dose at an unshielded clarification was developed to distinguish the placement distance of 2 m within 1 minute. The added sentence is of detectors vs. annunciators. No changes were made not clear and appears to change the regulatory as a result of this comment.

requirements from detecting 20 rads within 1 minute to a system capable of detecting 12 rad.

17 Nuclear Energy The exceptions of Section c.2.c (ANS-8.10) are not clear The NRC staff agrees in part with the comment. The Institute and appear misaligned with the regulatory definitions in language was modified in this RG to state that the 10 CFR 70.61(c). ANS-8.10 states shielding and licensee may use the more restrictive limits in ANS-8.10 confinement should be applied such that the total if it so chooses, or use the less restrictive limits from 10 effective dose to individuals outside the shielded and CFR 70.61.

confined area will not exceed 10 rem and the total 8

Response to Public Comments on Draft Regulatory Guide (DG)-3053, Rev. 3 No. Commenter Comment NRC Resolution effective dose to individuals outside the restricted area Also, we do not lower the regulatory definition of an will not exceed 0.5 rem. The draft guide states that the intermediate consequence event in 10 CFR 70.61(c) and dose limits in ANS-8.10 are more conservative than the NUREG-1520. The NRC staff accepts the use of less performance requirements in 10 CFR 70.61 and are restrictive values from the regulations in meeting the applicable. As currently written, the draft guide appears intent of the standard.

to lower the regulatory definition of an intermediate consequence event in 10 CFR 70.61(c) and NUREG-1520.

18 Nuclear Energy The exceptions of Section c.2.d (ANS-8.17) adds that The NRC staff disagrees with the comment. The NRC Institute licensees and applicants may perform a misload staffs position is that assignment of fuel burnup is to be analysis, along with additional administrative loading based on physical measurements to confirm reactor procedures to reduce the likelihood of a misload, in lieu records. In lieu of this, licensees may perform a misload of a quantitative measurement. Section 4.10 of ANS- analysis, and include additional loading procedures 8.17 allows both physical measurements and appropriate which reduce the probability of misloads. The use of analysis and verification to determine appropriate fuel analytical methods that take credit for burnup (e.g.,

burnup credit. NRC currently accepts analytical methods depletion and reactivity calculations) is a separate to determine burnup credit in criticality analyses per issue. This approach is consistent with current NRC NUREG/CR-6801, NUREG/CR-7109, and NEI 12-16, staff positions in ISG-8, Rev. 3. No changes were made Rev. 1. The draft guide endorsement of this standard as a result of these comments.

does not provide the flexibility to use currently acceptable practices to use a burnup analysis method and appears to be narrowly focused on loading spent fuel casks.

19 Nuclear Energy Section c.2.f (ANS-8.24) states that there should be See response to Comment 2. No changes were made Institute provision for periodic (e.g., annual) reverification of as a result of this comment.

computer codes. It is not clear why annual reverification is required if there are no changes to the computer code system. There is no added value to annual verification when software hasnt changed, and appears to be imposing a new regulatory staff position. Currently, the computer code system is verified prior to use on each production workstation used to perform transport calculations.

9