RIS 01-003: Changes, Tests, and Experiements

January 23, 2001


All U.S. NRC Part 50 and Part 72 licensees and Part 72 Certificate of Compliance holders.


The U.S. Nuclear Regulatory Commission (NRC) is issuing this regulatory issue summary (RIS) as guidance to addressees in making the transition to the requirements of recently amended regulations in Title 10 of the Code of Federal Regulations, namely, Sections 50.59 and 72.48 (10 CFR 50.59 and 10 CFR 72.48). Both sections are titled "Changes, tests, and experiments." This RIS requires no action or written response on the part of an addressee.

Background Information

On October 4, 1999, the NRC published final rules (64 FR 53582) amending 10 CFR 50.59 and 10 CFR 72.48. These regulations address licensee requirements for making changes to a facility (reactor facility, independent spent fuel storage installation, or monitored retrievable storage installation) without prior NRC approval. The effective date of 10 CFR 50.59, as amended, is 90 days after the issuance of applicable regulatory guidance. On November 14, 2000, the Commission approved for publication Regulatory Guide (RG) 1.187, "Guidance for Implementation of 10 CFR 50.59, Changes, Tests, and Experiments." The NRC noticed the availability of RG 1.187 in the Federal Register on December 13, 2000 (65 FR 77773). Therefore, the effective date of 10 CFR 50.59, as amended, is March 13, 2001. RG 1.187 endorses the industry guidance document developed by the Nuclear Energy Institute (NEI), NEI 96-07, Revision 1, "Guidelines for 10 CFR 50.59 Implementation," dated November 2000. A separate RG is being prepared to address the implementation of 10 CFR 72.48, as amended.

During the public comment process on the draft RG, the concern was expressed that it would be difficult for licensees to schedule and complete necessary procedure revisions and training within 90 days of the publication of the RG because of planned outage schedules and other activities. It was further noted that the effective date for 10 CFR 72.48, as amended, is a different date (April 5, 2001). This raised questions about how licensees could effectively transition from the existing rule to the amended rule.

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Summary of Issue

The issue addressed in this RIS is how the NRC will view licensee compliance with 10 CFR 50.59 and 10 CFR 72.48, as amended, when it finds a licensee observing the original requirements of either rule, as appropriate, after the effective date of the revision to each regulation. It is the NRC's view that since the amended 10 CFR 50.59 is a relaxation of the existing requirements, as a general matter, if a licensee is in compliance with the old rule, the licensee also satisfies the requirements of the amended rule. With regard to 10 CFR 72.48, the revisions to the rule were more extensive than those made to 10 CFR 50.59, particularly with regard to the reporting requirements. As a result, it is not possible to conclude that compliance with old rule also demonstrates compliance with the revised rule. However, it is the NRC's view that both the old rule and the new rule provide an acceptable level of safety. As a result, the NRC will consider scheduler exemptions to the effective date of 10 CFR 72.48 on a case-by-case basis for power reactor licensees that want to implement the revised 10 CFR 50.59 and 10 CFR 72.48 together. The NRC endorses the orderly transition to the requirements of the amended rules, even if a licensee implements them after their effective dates. More information on this matter is given in Attachment 1.

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Backfit Discussion

This RIS requires no action or written response. Consequently, the staff did not perform a backfit analysis.

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Federal Register Notification

The staff did not publish a notice of opportunity for public comment in the Federal Register because the RIS is informational and pertains to a staff position that does not represent a departure from current regulatory requirements and practice.

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Paperwork Reduction Act Statement

This RIS does not request any information collection.

If you have any questions about this issue, please call or e-mail one of the technical contacts listed below.

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David B. Matthews, Director
Division of Regulatory Improvement Programs
Office of Nuclear Reactor Regulation


E. William Brach, Director
Spent Fuel Project Office
Office of Nuclear Materials Safety and Safeguards

Technical Contacts: Eileen M. McKenna, NRR
E-mail: emm@nrc.gov
Christopher Jackson, NMSS
E-mail: cpj@nrc.gov
  1. Guidance on the Transition From the Original to the Amended Requirements of 10 CFR 50.59 and 10 CFR 72.48
  2. List of Recently Issued NRC Regulatory Issue Summaries

(ADAMS Accession Number ML010040446)

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RIS 2001-03



On October 4, 1999 (64 FR 53582), the NRC published a final rule revising 10 CFR 50.59 (and related requirements in 10 CFR Part 50 and 10 CFR Part 72). The Part 50 requirements were to become effective 90 days after issuance of applicable regulatory guidance. The effective date for the revised 10 CFR 50.59 is March 13, 2001, the amendments to 10 CFR 72.48 will become effective April 5, 2001. During the development of an industry guidance document on the implementation of 10 CFR 50.59 (endorsed by RG 1.187), certain issues arose concerning the transition from the old rule to the new rule. This attachment addresses these issues.


Issue 1: Licensees have planned refueling outages and other activities for the period between December and March 2001 and will find it difficult to complete necessary procedure revisions and train affected personnel before the rules become effective. To ease the transition to the new rules, may a licensee continue using the old rule after the effective date of either 10 CFR 50.59 or 10 CFR 72.48 until procedure revisions and training can be completed? Alternatively, could a licensee implement the revised Section 50.59 on the same date as the revised Section 72.48 (i.e., April 5, 2001)? What licensee actions are needed to do this?

Response: In promulgating the revisions to Sections 50.59 and 72.48, the Commission noted that the revised rules allow licensees greater flexibility than the existing rules to make changes without prior NRC approval. With regard to 50.59, if a licensee is appropriately implementing the old rule, it is complying with the amended rule. Some delay in implementation beyond the effective dates of the revised rules (a few months) is reasonable and acceptable. To make an orderly transition, licensees must have sufficient time to prepare procedures and train personnel. Although no formal notification of the NRC or NRC approval is needed to delay implementation, a licensee is encouraged to communicate its plans and implementation schedule to the NRC resident inspector and regional staff. A licensee may use the sample letter at the end of this attachment to communicate its plans to NRC staff. With regard to 10 CFR 72.48, because there are additional reporting requirements associated with the new rule, implementation of the revised 10 CFR 72.48 beyond April 5, 2001 date will require a scheduler exemption.

Issue 2: Which version of 10 CFR 50.59 or 10 CFR 72.48 applies when the evaluation of a change is begun before the effective date of the amended rule but not completed until after the amended rule becomes effective?

Response: The 10 CFR 50.59 or 10 CFR 72.48 requirements in effect when a licensee completes its evaluation of a change (i.e., when the safety review committee approves the change) will apply. Evaluations started after the effective date, should follow the revised rule.

Since the revised rule is a relaxation of the old rule, the NRC staff will consider an evaluation begun under the old rule and based on the procedures for the old rule but completed after the effective date of the revised rule to comply with the revised rule during the transition period. However, without a scheduler exemption, the reporting requirements associated with the revised 10 CFR 72.48 are applicable to all changes completed following the April 5, 2001 rule implementation date.

Issue 3: If a licensee completes an evaluation under the old rule but discovers new information after the revised rule takes effect and must revise the 10 CFR 50.59 or 10 CFR 72.48 evaluation, should the licensee use the new rule or the old rule to revise the evaluation?

Response: The licensee would need to comply with the rule that is in effect at the time the evaluation is revised. However, for 10 CFR 50.59 as previously noted, since the new rule is effectively a relaxation of the old rule, using the old rule to revise the evaluation is also acceptable. Only the parts of the evaluation affected by the new information need to be revised.

Issue 4: The effective date of the revised maintenance rule (10 CFR 50.65), including the new paragraph 50.65(a)(4), is November 28, 2000, which is before the effective date of the amended 10 CFR 50.59. During the time before 10 CFR 50.59 becomes effective, are licensees required to perform both paragraph 50.65(a)(4) assessments and 10 CFR 50.59 reviews for temporary alterations in support of maintenance?

Response: The guidance in RG 1.182 is that maintenance activities, including associated temporary alterations, are to be evaluated in accordance with paragraph 50.65(a)(4) of the maintenance rule. A 10 CFR 50.59 evaluation is not required (provided the temporary alteration will be in effect for less than 90 days at power). This same guidance is given in RG 1.187 for the implementation of 10 CFR 50.59. The revised rule explicitly states that a 10 CFR 50.59 evaluation is not needed when another regulation establishes the control process for such activities. However, the Commission, in approving RG 1.182, allowed licensees to use the guidance in RG 1.182 before the effective date of the amended 10 CFR 50.59. Therefore, if a licensee evaluates temporary alterations in accordance with paragraph 50.65(a)(4) of the maintenance rule, a 10 CFR 50.59 review is not needed.

Issue 5: If an evaluation has been completed before the effective date of either 10 CFR 50.59 or 10 CFR 72.48, as amended, but the change has not yet been implemented, what action (if any) is required?

p>Response: The new rule requires no action for changes evaluated but not implemented before the effective date of the rule. The licensee has the option of doing a new evaluation under the revised rule for changes that might have required prior approval under the old rule but do not require prior approval under the new rule. Such an evaluation would provide the basis for not seeking NRC approval for the change.

Issue 6: May a licensee continue to reference 10 CFR 50.59 or 10 CFR 72.48 evaluations performed under the old rule and guidance when making a similar change in the future?

Response: Past evaluations will continue to be a valuable resource to licensees for 10 CFR 50.59 or 10 CFR 72.48 screening and evaluations of similar changes. However, a licensee should use the definitions and criteria of the new rule and approved guidance for evaluations of proposed changes that are begun after the revised rule becomes effective (except as noted in Issue 1, above).

Issue 7: Some previous NRC documents that discuss 10 CFR 50.59 or 10 CFR 72.48 may be inconsistent with the revised rule or the new regulatory guidance, for example, Generic Letter (GL) 95-02 (regarding analog-to-digital upgrades under 10 CFR 50.59) and Bulletin (BL) 96-02 (regarding the movement of heavy loads). How should these documents be viewed now?

Response: NRC documents such as those noted were written to be used with the old rule. To the extent that the rule requirements that led to particular statements or conclusions have been revised, the impact of the rule revisions on those statements must be taken into account. For example, GL 95-02 discusses the evaluation criterion "malfunction of a different type." This criterion will no longer apply, having been revised to "malfunction with a different result." However, other aspects of the guidance (for example, the effect of the digital instrumentation on the system in which it is used) will remain applicable.

With respect to BL 96-02, if a heavy load movement is part of a maintenance activity, there is no 10 CFR 50.59 evaluation needed. The fact that the load is larger or is moving in a different load path than previously evaluated would enter into the risk assessment required by 10 CFR 50.65 (a)(4) and determine under what plant conditions the load lift should occur. If the heavy load lift is not maintenance related, and so requires a 10 CFR 50.59 evaluation, the licensee should follow the requirements of the revised rule to determine whether prior NRC approval is needed. For example, the licensee should consider whether the change would increase the consequences of an accident previously evaluated or creates an accident of a different type.

Issue 8: The implementation guidance endorsed in RG 1.187 appears to be written with power reactors in mind. How does implementation of the revised 10 CFR 50.59 apply to non-power reactors?

Response: The effective date of the revised 10 CFR 50.59 requirements, as established by publication of the Federal Register notice (65 FR 77773) announcing the availability of RG 1.187, applies to non-power reactors. As noted above, flexibility is allowed in the implementation period to accommodate training and procedural updating needs, and a properly executed program for complying with the old rule requirements will likely satisfy the new rule requirements during the implementation period. Non-power reactor licensees should note that some concepts in the revised rule such as a "method of evaluation described in the FSAR" may not have an equivalent in programs based on the old rule. The NRC staff will accept and reply to questions from non-power reactor licensees that my arise during implementation of the new rule.


TO: NRC, Document Control Desk, Washington DC 20555
FROM: Appropriate Licensee Point of Contact

The effective date for the revised 10 CFR 50.59, was established in a December 13, 2000, Federal Register notice (65 FR 77773), as March 13, 2001. As discussed in Regulatory Issue Summary (RIS) 2001-03, dated January 23, 2001, the NRC has stated that to permit an orderly transition to the revised rule, licensees may implement the rule later than this date. Although an exemption is not necessary, the RIS suggested that a licensee may want to communicate its implementation plan to the NRC. It is our intention to implement the revised requirements of 10 CFR 50.59 on [date]. [Here the licensee may add any information about its plans to phase in 10 CFR 50.59 implementation; for example, the licensee will follow the new rule requirements for evaluations begun after the date provided, but will finish other evaluations under the old process]. Until that time, we will continue to implement our existing 10 CFR 50.59 review processes.

[The licensee may discuss its reasons for delaying implementation. For example, the plant will be in a refueling outage shortly after the effective date, and there is insufficient time to train personnel in the revised process; or the licensee does not want to transition during a refueling outage since this activity already places demands on staff and would not be in the best interests of safety; or the licensee wants to implement the revised section 50.59 at the same time as the revised section 72.48, to minimize confusion.]

cc: NRC Regional Office
NRC Resident Inspection Office(s) [as applicable]
NRR Project Managers (for affected facilities)
E. McKenna, NRR/RGEB

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Page Last Reviewed/Updated Wednesday, March 24, 2021