ULNRC-06202, Transmittal of 10 CFR 50.59 and 10 CFR 72.48 Summary Report

Transmittal of 10 CFR 50.59 and 10 CFR 72.48 Summary Report

ML15142A501
Person / Time
Site:	Callaway
Issue date:	05/22/2015
From:	Maglio S Ameren Missouri, Union Electric Co
To:	Document Control Desk, Office of Nuclear Material Safety and Safeguards, Office of Nuclear Reactor Regulation
References
ULNRC-06202
Download: ML15142A501 (9)

Text

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'WAmeren Callaway Plant MISSOURI May 22,2015 ULNRC-06202 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 10 CFR 50.59(d)(2) 10 CFR 72.48(d)(2)

Ladies and Gentlemen:

DOCKET NUMBERS 50-483 AND 72-1045 CALLAWAY PLANT UNIT 1 UNION ELECTRIC CO.

RENEWED FACILITY OPERATING LICENSE NPF-30 10 CFR 50.59 AND 10 CFR 72.48

SUMMARY

REPORT In accordance with 10 CFR 50.59(d)(2), this letter transmits a report that summarizes the evaluations performed pursuant to 10 CFR 50.59(c)(1) for changes, test, and experiments approved and implemented for activities at Callaway Plant. This report covers all 10 CFR 50.59 evaluations that were implemented from May 28,2013 to November 22, 2014.

Union Electric Company (dba Ameren Missouri) did not perform any evaluations at Callaway Plant required by 10 CFR 72.48 between May 28, 2013 and November 22, 2014. Therefore, no summaries of evaluations are provided in this report per 10 CFR 72.48(d)(2) for Callaway Plant.

This letter does not contain new commitments.

Ifthere are any questions, please contact Mr. Tom Elwood at (314) 225-1905.

Sincerely, L\e,ot\

Scott Maglio 0

Manager, Regulatory Affairs Enclosure

.......................................................................................................................... PO Box 620 Fulton, MO 65251 AmerenMissouri.com ...............

STARS

• Alliance

ULNRC-06202 May 22,2015 Page2 cc: Mr. Marc L. Dapas Regional Administrator U.S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 Senior Resident Inspector Callaway Resident Office U.S. Nuclear Regulatory Commission 8201 NRC Road Steedman, MO 65077 Mr. L. John Klos Project Manager, Callaway Plant Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Mail Stop 0-8B 1 Washington, DC 20555-2738

ULNRC-06202 May 22,2015 Page 3 Index and send hardcopy to QA File A160.0761 Hardcopy:

Certrec Corporation 4150 International Plaza Suite 820 Fort Worth, TX 76109 (Certrec receives ALL attachments as long as they are non-safeguards and may be publicly disclosed.)

Electronic distribution for the following can be made via Responses and Reports ULNRC Distribution:

F. M. Diya D. W. Neterer L. H. Graessle T. E. Herrmann B.L.Cox S. A. Maglio T. B. Elwood Corporate Communications NSRB Secretary STARS Regulatory Affairs Mr. John O'Neill (Pillsbury Winthrop Shaw Pittman LLP)

Enclosure to ULNRC-06202 UNION ELECTRIC COMPANY (dba AMEREN MISSOURI)

CALLAWAY PLANT DOCKET NO. 50-483 AND 72-1045 10 CFR 50.59 and 10 CFR 72.48

SUMMARY

REPORT Report Period: May 28, 2013 to November 22, 2014.

Enclosure to ULNRC-06202 EXECUTIVE

SUMMARY

In accordance with 10 CFR 50.59(d)(2), a summary report has been prepared which provides summaries of the 10 CFR 50.59 evaluations of changes, tests, and experiments approved and implemented for activities at Callaway Plant.

This report covers all10 CFR 50.59 evaluations for changes that were implemented from May 28,2013 to November 22,2014. During this period there were five changes implemented that required a 10 CFR 50.59 evaluation. For two of the changes, it was determined that prior NRC approval was required. Those changes were approved via Amendments 207 and 211 to the Callaway Operating License, and therefore, summaries of those changes do not need to be provided in this report. For the remaining three changes, it was determined per 10 CFR 50.59(c)(1) that NRC approval was not required, and therefore, summaries of those three 10 CFR 50.59 evaluations are hereby provided.

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Enclosure to ULNRC-06202 10 CFR 50.59 EVALUATIONS:

Evaluation Number: Activity:

13-03 MP 10-0001, Implement an Integrated Head Assembly (IHA) in RF20 in Support of the Replacement Reactor Vessel Head Closure Head (RRVCH) Project 13-05 LDCN 13-0013, Pressurizer Pressure 13-06 LDCN 13-0017, Containment Cooler Post-accident Heat Removal Rate 10 CFR 72.48 EVALUATIONS:

I Evaluation Number: I Activity:

None LDCN- Licensing Document Change Notice MP -Modification Package Page 2 of 5

Enclosure to ULNRC-06202 10 CFR 50.59 Evaluation 13-03: Modification Package (MP) 10-0001- Implement an Integrated Head Assembly (IHA) in RF20 in Support of the Replacement Reactor Vessel Head Closure Head (RRVCH) Project Activity

Description:

This activity involves replacing the existing Service Structure (SS) currently installed above the original reactor vessel closure head (ORVCR) with an integrated head assembly (IRA) that will be installed above the replacement reactor vessel closure head (RRVCH). A 10 CFR 50.59 Evaluation was performed to evaluate potential departures from an FSAR-described evaluation methodology associated with the use of computer codes for stress analysis and reactor vessel Head Drop Analysis that are not described in the FSAR. The following three methodology changes were evaluated:

1. The piping and supports structural analysis for the replacement Reactor Vessel Head Vent System (RVHVS) and replacement Reactor Vessel Level Indication System (RVLIS) involve the use of the computer code BWSPAN (in lieu ofWESDYN and PA CAEPIPE). BWSPAN is currently not included in FSAR Table 3.9(B)-1 (Computer Programs Used in Analysis).

2. The Westinghouse EMDAC code is being used for the reactor vessel structural analysis (in lieu ofWECAN code). EMDAC is currently not included in FSAR Table 3.9(B)-1 (Computer Programs Used in Analysis).

3. The reactor vessel head drop analysis (which is described in FSAR-SP 9.1.4.3) is being re-performed using a modem finite element analysis that includes the Integrated Head Assembly (in lieu of the classic model ofWCAP-9198). RIS 2008-28 (NEI 08-

05) describes the methodology to evaluate a drop of the reactor head. Per the RIS, "Licensees may use these guidelines to voluntarily establish a revised licensing basis for handling of reactor vessel heads and other heavy loads that is consistent with the provisions ofTitle 10 ofthe Code ofFederal Regulations (10 CFR) Section 50.59, "Changes, Tests and Experiments."

Summary of Evaluation:

The 10 CFR 50.59 Evaluation concluded that for items 1 and 2 the new methodologies proposed to be used are essentially the same as the methodologies currently described in the FSAR, and do not constitute a departure from an FSAR-described methodology. For item 3 the methodology described in NEI 08-05 is allowed without prior NRC approval. Therefore, the proposed methodology changes (described above) may be implemented without prior approval by the NRC.

Page 3 of 5

Enclosure to ULNRC-06202 10 CFR 50.59 Evaluation 13-05: Pressurizer Pressure Activity

Description:

This activity involves reducing the pressurizer pressure value associated with Technical Specification (TS) 3.4.1, "RCS Pressure, Temperature, and Flow Departure from Nucleate Boiling (DNB) Limits," from -30 psi to -60 psi. LCO 3.4.1(a) requires that "Pressurizer Pressure is greater than or equal to the limit specified in the COLR." The COLR is contained in Callaway Curve Book Figure 13-1, and the current value for COLR item 2.11 (per Revision

56) is~ 2,224 psig. With the additional-30 psi bias being added to the current -30 psi uncertainty value, the allowable minimum indicated pressure used by the control room operators to verify compliance with TS 3.4.1 will be 2,195 psig.

This reduction in the low pressure uncertainty value (from the current value of -30 psi to a new value of -60 psi) is to prevent temporary entries into Condition A of Technical Specification 3.4.1 during routine changes in plant power.

Summary of Evaluation:

Callaway Plant received revisions of FSAR Chapter 15 analysis from Westinghouse. This provided verification that adding an additional-30 psi bias to the existing -30 psi low pressure uncertainty value still keeps Callaway Plant within the analysis acceptance criteria needed to maintain safe operation of the plant in all of the associated Chapter 15 accidents potentially affected by this reduction of pressure.

It is therefore concluded that the addition of a -30 psi bias to the existing+/- 30 psi uncertainty band for the Pressurizer Pressure value associated with Technical Specification (TS) 3.4.1 does not require prior NRC approval.

Page 4 of 5

Enclosure to ULNRC-06202 10 CFR 50.59 Evaluation 13-06: Containment Cooler Post-accident Heat Removal Rate Activity

Description:

The activity involves a reduction in the required level of Containment Cooler performance credited in Callaway's current licensing bases from 141.4 E6 BTU/Hr to 100 E6 BTU/Hr under accident conditions. The proposed change is necessary due to the need to make allowances for substantial uncertainties associated with testing the containment coolers under normal operating conditions and then extrapolating the test results to determine cooler performance under accident conditions.

Summary of Evaluation:

Ameren performed calculations to analyze the effect of reduced containment cooler performance on post-accident containment environments. These calculations demonstrate that the proposed changes do not affect previously calculated values for peak post-accident pressure or temperature.

There is a slight increase in the post-peak pressure and temperature compared to previously calculated values. The reduction in credited cooler performance slows the removal of energy from the post-accident containment vapor space, which results in the higher tail-end pressures and temperatures. An Environmental Qualification review of the revised containment pressure and temperature values, however, determined that the proposed change does not present an unacceptable adverse impact on the capability of safety-related equipment located inside containment to perform its specified safety functions and meet mission time requirements.

Therefore, the proposed change to Callaway's current licensing basis may be implemented without prior approval by the NRC.

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