[Federal Register Volume 64, Number 125 (Wednesday, June 30, 1999)]
[Notices]
[Pages 35194-35197]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-16597]
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NUCLEAR REGULATORY COMMISSION
Licensee Qualification for Performing Safety Analyses; Issue
AGENCY: Nuclear Regulatory Commission.
ACTION: Notice of Issuance.
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SUMMARY: The Nuclear Regulatory Commission (NRC) has issued Supplement
1 to Generic Letter (GL) 83-11, Licensee Qualification for Performing
Safety Analyses, to all holders of operating licenses for nuclear power
reactors. This GL supplement presents criteria that licensees may
choose to comply with to verify to the NRC their qualifications to use
approved codes and methods for performing safety analyses.
DATES: The GL supplement was issued on June 24, 1999.
ADDRESSES: Not applicable.
FOR FURTHER INFORMATION CONTACT: Laurence I. Kopp, Office of Nuclear
Reactor Regulation, U.S. Nuclear Regulatory Commission, telephone 301-
415-2879, e-mail [email protected].
SUPPLEMENTARY INFORMATION: In 1995, the Nuclear Regulatory Commission
(NRC) prepared a draft of a supplement to Generic Letter 83-11,
Licensee Qualification for Performing Safety Analyses, for the purpose
of presenting criteria that licensees may choose to comply with to
verify to the NRC their qualifications to use approved codes and
methods for performing safety analyses. By complying with these
criteria, a licensee would eliminate the need to submit a topical
report for qualifying their use of a previously approved methodology. A
notice of opportunity for public comment including a draft of the
supplement were published in the Federal Register on October 25, 1995
(60 FR 54712). NRC staff responses to the comments received are
presented below under the heading ``Discussion of Comments.''
The NRC subsequently decided to cancel the issuance of the generic
letter supplement primarily because of issues that had arisen at a
nuclear power facility (Maine Yankee) regarding the improper
application of approved methods. At that time, the NRC concluded that
the potential reduction in staff oversight which would result from its
issuance was not justified. A notice of cancellation was published in
the Federal Register on October 30, 1996 (61 FR 56069). The specific
issue that arose concerned the licensee's failure to comply with all of
the restrictions and conditions stated in the
[[Page 35195]]
staff's safety evaluation report (SER) for proper application of a
loss-of-coolant-accident (LOCA) code.
A review of the lessons learned from Maine Yankee has indicated
that the issue involved was adequately addressed in the generic letter
supplement as published for public comment on October 25, 1995, because
the supplement requires that licensees adhere to all limitations and
restrictions in the staff's SER. Further, this supplement to GL 83-11
does not apply to LOCA codes. Therefore, the NRC determined that there
would be no reduction in staff oversight and decided to proceed with
issuance of the supplement.
The GL supplement is available in the NRC Public Document Room
under accession number 9906210103.
Discussion of Comments
Comments were received from 13 licensees, 3 fuel vendors, and 3
industry interest groups, in response to the notice of opportunity for
public comment noted above. Following are the staff responses to
comments received on the proposed GL 83-11 supplement:
Studsvik of America, Inc.
Comment: Clarify that ``safety analysis'' includes the physics
parameters and codes used to generate them.
Response: Clarification has been made in both the Purpose section
and 2.0 Guidelines section.
Comment: For physics codes, approval of code should be separate
from the application method.
Response: Section 2.2 has been modified to clarify that in some
instances the approval of the code is separate from the application
method.
Comment: Clarification of what constitutes NRC approval of a code
and/or method would be helpful.
Response: Section 2.1 has been modified to clarify the eligibility
of codes and methods for this process.
Comment: Clarify what constitutes a significant code and/or
methodology update that must be reviewed by the NRC.
Response: What constitutes a significant code or methodology update
that must be reviewed by the NRC is too complex a topic to fully
address in a generic manner at this time. However, as mentioned in the
Federal Register notice (October 25, 1995 (60 FR 54712)), the NRC is
also investigating modified procedures for reducing the resource effort
for acceptance of new or revised licensee or vendor analysis methods.
Therefore, it is anticipated that this topic will be addressed at a
future date.
Westinghouse Electric Corporation
Comment: Reemphasize that NRC's experience has shown that a large
percentage of all errors or discrepancies discovered in safety analyses
can be traced to the user rather than the code itself.
Response: The fact that NRC's experience has shown that many times
errors or discrepancies discovered in safety analyses can be traced to
the user rather than the code itself is stated in the Description of
Circumstances section.
Florida Power & Light Company
Comment: NRC should allow licensees to modify the Core Operating
Limit Report (COLR) without specific NRC review so long as the methods
and codes have already been approved by the NRC.
Response: The issuance of this supplement would allow this
modification as long as the approved methodology is referenced in the
technical specifications. The Introduction and Section 2.0 have been
modified to address this.
Duke Power Company
Comment: NRC should generically lift restrictions included in
topical report SERs that restricted application of the methodology to
the plants operated or supported by the licensee of the methodology.
Response: The issuance of this supplement would generically lift
these restrictions. However, any other limitations stated in the SERs
should be adhered to.
Comment: The introduction should state that the codes are developed
by vendors, utilities, national labs, or organizations like EPRI.
Response: The proposed statement has been added to the
Introduction.
Comment: The scope of safety analyses should be defined to cover
any analytical areas including reload physics design, core thermal-
hydraulics, fuel mechanical analysis, transient analysis, dose
analysis, setpoint analysis, containment analysis, criticality
analysis, statistical methods, and any other analytical area for which
topical reports have been approved by the NRC.
Response: The suggested clarification has been incorporated in the
Purpose and 2.0 Guidelines sections, with the exception of LOCA
analysis codes.
Nuclear Energy Institute
Comment: Recommends deletion of last two items in Section 2.5.
Response: The NRC believes that the two items emphasized are of
sufficient significance to be explicitly stated.
Comment: Recommends rewording of Section 2.4 so as not to imply all
of the suggested set of benchmark data is required.
Response: The wording in Section 2.4 has been modified to clarify
that these are examples of appropriate benchmark data and are not all
required.
Commonwealth Edison Company
Comment: Terminology and criteria are open to interpretation. For
example, in Section 2.4, what the licensee may think is appropriate
justification for an observed deviation in comparison calculations may
satisfy one reviewer but not another.
Response: Suggested rewording for benchmark deviations has been
added to Section 2.4 to eliminate ambiguity.
Comment: The intent of the term ``application procedure'' in
Section 2.2 could be misinterpreted.
Response: Section 2.2 has been revised for clarification.
Comment: Section 2.4 should be revised to read ``Significant,
unexpected, or unusual deviations should be * * *''
Response: The suggested rewording has been added to Section 2.4.
Comment: Vendor update implementation in Section 2.5 should be
clarified so as not to imply that all changes that vendor makes must be
implemented.
Response: Section 2.5 Item (1) has been modified to allow an
evaluation of updates to determine if implementation is required.
Electric Power Research Institute
Comment: Questions whether a licensee must base the methodology on
a previously approved plant SER or can develop a ``new'' topical based
only on the generic code SER?
Response: By adhering to the guidelines in the supplement, a
licensee can perform its own analyses using any approved code or
method.
Comment: For clarity, the words ``application of the'' should be
deleted from Section 2.2.
Response: The in-house application procedures should be consistent
with the code qualification and approved application of the
methodology. Therefore, this has been retained in Section 2.2.
Comment: Training should be performed by either the developer or
someone who has been previously qualified.
Response: The proposed wording has been added to Section 2.3.
[[Page 35196]]
Comment: ``Vendor'' analysis should be changed to ``analysis of
record.''
Response: The proposed rewording has been added to Section 2.4.
Comment: An appropriate set of benchmark data should include
analysis of events, using higher order codes or published numerical
benchmarks.
Response: The proposed wording has been added to Section 2.4.
Comment: In Section 2.4, ``Any deviations'' should be explained.
Response: A revision has been made to Section 2.4 to more clearly
define deviations that must be explained.
Southern Nuclear Operating Company
Concurs with NEI comments.
GPU Nuclear Corporation
Comment: It seems appropriate to identify existing codes and
methodologies that have been developed by national labs for the NRC
that can be considered NRC approved codes and methods.
Response: The identification of existing codes and methodologies
developed by national labs that can be considered as NRC approved codes
and methods, even though formal NRC review and approval has never been
performed, is beyond the scope of this proposed supplement.
Comment: Suggests that the terms ``codes'', ``methods'', and
``applications'' be clearly defined.
Response: A definition of codes, methods, and applications has been
added to the Introduction.
Siemens Power Corporation
Supports the approaches described in the proposed supplement.
Virginia Power
Endorses the proposed supplement.
Pacific Gas and Electric Company
Comment: Concept should not be limited to core analysis.
Response: The specific analytical areas that the GL refers to have
been added to the Purpose Section.
Comment: NRC should allow the training requirement to be met by on-
the-job training.
Response: A new user can be qualified by on-the-job training as
well as by formal classroom instruction. In many cases, user
qualification will be accomplished by a combination of both
Yankee Atomic Electric Company (YAEC)
Comment: It is YAEC's understanding that the supplement will only
apply to licensees who use another organization's methods and codes,
and not to an organization that receives approval for its own codes and
methods, and conducts safety analyses using those codes and methods.
Response: YAEC's interpretation is correct.
Comment: Recommends that the supplement also note that other
organizations such as utilities and engineering service companies have
developed codes and methods.
Response: The example of possible code developers has been modified
to include utilities and national labs.
Indiana Michigan Power Company
Comment: Suggests that different versions of previously approved
codes should be applicable as long as the calculational methodology is
not changed.
Response: Section 2.1 has been modified to clarify code
eligibility. What constitutes a significant code or methodology update
that must be reviewed by the NRC is too complex a topic to fully
address in generic terms at this time. However, as mentioned in the
Federal Register notice (60 FR 54712; October 25, 1995), the NRC is
also investigating modified procedures for reducing the resource effort
for acceptance of new or revised licensee or vendor analysis methods.
Therefore, it is anticipated that this topic will be addressed at a
future date.
Entergy Operations, Incorporated
Comment: The applicability of a particular method to either a
specific fuel design or to a core which contains a mixture of fuel
types is important. Use of one vendor's hot channel analysis code with
another's transient codes may not necessarily yield conservative
results and may not be consistent with the NRC-approved reload analysis
package. In-house application procedures should have proper controls to
preclude such a misapplication, and should be permitted to include the
flexibility to perform comparison tests between the different
methodologies to show that a conservative assessment can be made.
Response: Section 2.2 has been modified to incorporate this
application procedure.
Comment: NRC should consider issuing an inspection procedure
concurrently with the supplement so that licensees would know what
questions and documentation requests might be needed to support audits.
Response: The NRC will incorporate oversight of this GL supplement
into the NRC inspection program following the issuance of this
supplement.
Comment: NRC should consider providing licensees the flexibility to
conduct its own assessment of a third party reviewer similar to what is
currently allowed in NRC Inspection Module 40501.
Response: Issuance of this supplement would eliminate the need to
submit a qualification topical report for NRC review and thus eliminate
the need for a third party reviewer.
Arizona Public Service (APS)
Comment: The ``first licensing application'' is interpreted by APS
as being the first proposed license amendment or other licensing basis
change requiring prior NRC review and approval that was supported by
safety analyses performed by the licensee instead of a vendor.
Response: The ``first licensing application'' may not necessarily
be a licensing basis change requiring NRC approval before
implementation, but may be a revision to a COLR parameter, for example.
Comment: APS would interpret ``eligibility'' in Section 2.1 to mean
that code packages previously approved in topical reports or license
amendments for other plants would be generically approved.
Response: The only codes and methods that are eligible for this
process are those that have been generically approved, or those that
have been otherwise accepted as part of a plant's licensing basis.
Section 2.1 has been modified to clarify this.
Comment: APS suggests that plant specific uncertainties could be
used without additional NRC review, even if these uncertainties are
less than the generically approved uncertainties.
Response: As a general rule, plant specific uncertainties may be
used without additional NRC review provided that they are derived with
previously approved methods. However, NRC review is required for
modifications to uncertainties that were generically approved to cover
uncertainties due to codes and methods, correlations, etc.
Comment: APS states that they would control changes to methodology
by design control procedures and that the changes would be subject to
10 CFR 50.59 evaluations, if appropriate.
Response: As stated in Section 2.1, the use of a new methodology or
a change to an existing methodology is not applicable to this process.
However, as mentioned in the Federal Register notice (60 FR 54712;
October 25, 1995), the NRC is also investigating modified procedures
for reducing the resource effort for acceptance of new or revised
[[Page 35197]]
licensee or vendor analysis methods. Therefore, it is anticipated that
this topic will be addressed at a future date.
Comment: APS considers an appropriate set of benchmark data to
include other acknowledged industry standard data or criteria.
Response: The examples of appropriate benchmark data has been
expanded to include APS' suggestions.
Comment: APS suggests that Section 2.5 be revised to allow a
provision for evaluating vendor updates and implementing those updates,
if applicable.
Response: The proposed rewording has been incorporated into Section
2.5.
Centerior Energy
Comment: The guidance should be explicit enough to allow for
utilities to reference topical reports submitted by non-NSSS vendors.
Response: Utilities have been added to the example of organizations
that develop methods.
Comment: The proposed guidance should be sufficiently flexible to
allow substitution of computer codes within an approved analytical
methodology.
Response: The Application Procedures have been modified to allow
this, but should contain proper controls to preclude misapplications or
inappropriate use of an application.
Comment: NRC should maintain a listing of the codes or methods it
has approved.
Response: The NRC is currently developing a data base of approved
codes as a separate action.
Comment: NRC should define the point at which reapproval of updates
is necessary.
Response: What constitutes a significant code or methodology update
that must be reviewed by the NRC is too complex a topic to fully
address in generic terms at this time. However, as mentioned in the
Federal Register notice (60 FR 54712; October 25, 1995), the NRC is
also investigating modified procedures for reducing the resource effort
for acceptance of new or revised licensee or vendor analysis methods.
Therefore, it is anticipated that this topic will be addressed at a
future date.
For the Nuclear Regulatory Commission.
Dated at Rockville, Maryland, this 24th day of June, 1999.
James E. Lyons,
Deputy Chief, Events Assessment, Generic Communications and Non-Power
Reactors Branch, Division of Regulatory Improvement Programs.
[FR Doc. 99-16597 Filed 6-29-99; 8:45 am]
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