ML21319A006

Supplemental Information Needed for Acceptance of Requested Licensing Actions License Amendment Request for Adoption of Alternate Source Term and Revision of Technical Specifications

ML21319A006
Person / Time
Site:	Callaway
Issue date:	11/30/2021
From:	Mahesh Chawla Plant Licensing Branch IV
To:	Diya F Union Electric Co
Chawla M
References
EPID L-2021-LLA-0177
Download: ML21319A006 (5)

Text

November 30, 2021 Mr. Fadi Diya Senior Vice President and Chief Nuclear Officer Ameren Missouri Callaway Energy Center 8315 County Road 459 Steedman, MO 65077

SUBJECT:

CALLAWAY PLANT, UNIT NO. 1 - SUPPLEMENTAL INFORMATION NEEDED FOR ACCEPTANCE OF REQUESTED LICENSING ACTIONS RE: LICENSE AMENDMENT REQUEST FOR ADOPTION OF ALTERNATE SOURCE TERM AND REVISION OF TECHNICAL SPECIFICATIONS (EPID L-2021-LLA-0177)

Dear Mr. Diya:

By letter dated September 28, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21272A167), Union Electric Company, dba Ameren Missouri (the licensee) submitted a license amendment request for Callaway Plant, Unit No. 1 (Callaway).

Pursuant to Title 10 of Code of Federal Regulations (10 CFR) Section 50.90, Application for amendment of license, construction permit, or early site permit, and 10 CFR 50.67, Accident Source Term, the licensee requested to incorporate the alternative source term dose analysis methodology into the Callaway licensing basis and to revise Callaway Technical Specifications 3.7.10, Control Room Emergency Ventilation System (CREVS); 5.5.11, Ventilation Filter Testing Program (VFTP); and 5.5.17, Control Room Envelope Habitability Program.

The purpose of this letter is to provide the results of the U.S. Nuclear Regulatory Commission (NRC) staffs acceptance review of this amendment request. The acceptance review was performed to determine if there is sufficient technical information in scope and depth to allow the NRC staff to complete its detailed technical review. The acceptance review is also intended to identify whether the application has any readily apparentinformation insufficiencies in its characterization of the regulatory requirements or the licensingbasis of the plant.

Consistent with 10 CFR 50.90, an application for an amendment to a license (including the technical specifications) must fully describe the changes requested, and following as far as applicable, the form prescribed for original applications. Section 50.34 of 10 CFR addresses the content of technical information required. This section stipulates that the submittal address the design and operating characteristics, unusual or novel design features, and principal safety considerations.

The NRC staff has reviewed your application and concluded that the information delineated in the enclosure to this letter is necessary to enable the staff to make an independent assessment regarding the acceptability of the proposed amendment request in terms of regulatory requirements for the protection of public health and safety and the environment.

F. Diya In order to make the application complete, the NRC staff requests that the licensee supplement the application to address the information requested in the enclosure by December 1, 2021.

This will enable the NRC staff to begin its detailed technical review. If the information responsive to the NRC staffs request is not received by the above date, the application will not be accepted for review pursuant to 10 CFR 2.101, Filing of application, and the NRC will cease its activities associated with the application. If the application is subsequently accepted for review, you will be advised of any further information needed to support the NRC staffs detailed technical review by separate correspondence.

The information requested and associated timeframe in this letter were discussed with Mr. Thomas Elwood of your staff on November 10, 2021.

If you have any questions regarding this matter, please contact me at 301-415-8371, or by e-mail to Mahesh.Chawla@nrc.gov.

Sincerely,

/RA/

Mahesh L. Chawla, Project Manager Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-483

Enclosure:

Supplemental Information Needed cc: Listserv

SUPPLEMENTAL INFORMATION NEEDED LICENSE AMENDMENT REQUEST FOR ADOPTION OF ALTERNATE SOURC TERM AND REVISION OF TECHNICAL SPECIFICATIONS UNION ELECTRIC COMPANY CALLAWAY PLANT, UNIT NO. 1 DOCKET NO. 50-483 By letter dated September 28, 2021 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML21272A167), Union Electric Company, dba Ameren Missouri (the licensee) submitted a license amendment request (LAR) for Callaway Plant, Unit No. 1 (Callaway). Pursuant to Title 10 of Code of Federal Regulations (10 CFR) Section 50.90, Application for amendment of license, construction permit, or early site permit, and 10 CFR 50.67, Accident Source Term, the licensee requested to incorporate the alternative source term dose analysis methodology into the Callaway licensing basis and to revise Callaway Technical Specifications 3.7.10, Control Room Emergency Ventilation System (CREVS);

5.5.11, Ventilation Filter Testing Program (VFTP); and 5.5.17, Control Room Envelope Habitability Program.

REGULATORY BASIS During its acceptance review of the licensees submittal, the NRC staff identified that it required additional information to be able to confirm direct input to the licensees radiological dose evaluation. In particular, data and information related to the accident-related onsite and offsite atmospheric dispersion models and the meteorological (Met) data input to them. These needs were discussed during previous pre-application submittal meetings. The required data and information are identified below.

The regulatory basis for this request is first rooted in the phrase following as far as applicable, the form prescribed for original applications, from the regulation at 10 CFR 50.90.

The regulation at 10 CFR 50.67(b)(1) go on to state that [t]he application shall contain an evaluation of the consequences of applicable design-basis accidents previously analyzed in the safety analysis report. In turn, the regulation at 10 CFR 50.67(b)(2) requires that the applicant's analysis demonstrates with reasonable assurance that the dose limits at any point on the exclusion area boundary (EAB) and the outer boundary of the low population zone (LPZ),

and at the control room, are met. Those dose analyses require, as a direct input, dispersion parameters, which are based on the use of appropriate dispersion models that rely, in part, on the input of representative Met data.

BACKGROUND INFORMATION Several items needed to support the NRC staffs technical review were initially identified during a discussion at the June 14, 2018, pre-submittal LAR meeting, and as described in the meeting summary dated August 21, 2018 (ADAMS Accession No. ML18215A375). The August 21, 2018, meeting summary was also referenced in the meeting summary dated April 16, 2021 (ADAMS Accession No. ML21103A003), of a subsequent pre-submittal meeting held on Enclosure

March 15, 2021. Items called for in the June 14, 2018, meeting, to be part of the AST LAR submittal that the NRC staff finds were not included, are:

Item 20.c Provide sequential hourly (ASCII-character) data files for each year in accordance with the format in Appendix A of RG 1.23, Revision 1, including respective units of measure. If a different submission is made, please explain the data format provided.

Item 20.d Provide sequential hourly (ASCII-character) data files in format, required for input to ARCON96 including respective units of measure.

Item 21.c A submittal of the text files of [PAVAN or PAVAN-NAI] model input and output for all runs.

Item 22.c A submittal of the text files of [ARCON96 or ARCON96-NAI] model input and output for all runs.

The Met data files in Items 20.c and 20.d are reviewed and needed as input to NRCs confirmatory PAVAN and ARCON96 dispersion model runs. The text files called for in Items 21.c and 22.c are reviewed and used to build the confirmatory model run files of the dispersion analyses at offsite (i.e., the EAB and outer boundary of the LPZ) and onsite (control room and technical support center) receptors.

Further, the NRC staff notes that the licensee cited dispersion models of different names (i.e.,

PAVAN-NAI and ARCON96-NAI) in its presentation slides during pre-application meetings. On the other hand, the proposed revisions to the Callaway Updated Final Safety Analysis Report appear to refer only to the NRC versions of the PAVAN and ARCON96 dispersion models. As a result, it cannot yet be concluded that either PAVAN and PAVAN-NAI and/or ARCON96 and ARCON96-NAI are equivalent.

SUPPLEMENTAL DATA AND INFORMATION NEEDED

1) Provide the requested Met data and dispersion model input and output files identified in Items 20.c, 20.d, 21.c, and 22.c as indicated in ADAMS Accession No. ML18215A375 and discussed during our clarification call of October 27, 2021.

2) Clarify any differences between the PAVAN and PAVAN-NAI and the ARCON96 and ARCON96-NAI dispersion models.

ML21319A006 *by e-mail OFFICE NRR/DORL/LPL4/PM* NRR/DORL/LPL4/LA* NRR/DEX/EXHB/BC NAME MChawla PBlechman BHayes DATE 11/15/2021 11/15/2021 11/15/2021 OFFICE NRR/DORL/LPL4/BC* NRR/DORL/LPL4/PM*

NAME JDixon-Herrity MChawla DATE 11/30/2021 11/30/2021