ML12270A147

Request for Additional Information for the Review of the Callaway Plant Unit 1 License Renewal Application, Set 14

ML12270A147
Person / Time
Site:	Callaway
Issue date:	10/03/2012
From:	Cuadradodejesus S License Renewal Projects Branch 1
To:	Heflin A Union Electric Co
Cuadrado S, 415-2946
References
TAC ME7708
Download: ML12270A147 (7)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 October 3,2012 Mr. Adam C. Heflin Senior Vice President and Chief Nuclear Officer Union Electric Company P.O. Box 620 Fulton, MO 65251

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE CALLAWAY PLANT, UNIT 1. LICENSE RENEWAL APPLICATION, SET 14 (TAC NO. ME7708)

Dear Mr. Heflin:

By letter dated December 15, 2011, Union Electric Company d/b/a Ameren Missouri (the applicant) submitted an application pursuant to Title 10 of the Code of Federal Regulations Part 54 (10 CFR Part 54) for renewal of Operating License No. NPF-30 for the Callaway Plant Unit 1 (Callaway). The staff of the U.S. Nuclear Regulatory Commission (NRC or the staff) is reviewing this application in accordance with the guidance in NUREG-1800, *Standard Review Plan for Review of License Renewal Applications for Nuclear Power Plants." During its review, the staff has identified areas where additional information is needed to complete the review.

The staffs requests for additional information are included in the enclosure. Further requests for additional information may be issued in the future.

Items in the enclosure were discussed with Sarah G. Kovaleski, of your staff, and a mutually agreeable date for the response is within 30 days from the date of this letter. If you have any questions, please contact me by telephone at 301-415-2946 or bye-mail at Samuel. CuadradoDeJesus@nrc.gov.

Sincerely,

~cua:a£.~2:er Projects Branch 1 Division of License Renewal Office of Nuclear Reactor Regulation Docket No. 50-483

Enclosure:

Requests for additional information cc w/encl: Listserv

CALLAWAY PLANT. UNIT 1 LICENSE RENEWAL APPLICATION REQUEST FOR ADDITIONAL INFORMATION. SET 14 RAI A1.17-1

Background:

The Callaway Plant, Unit 1 (Callaway), license renewal application (LRA), Section A 1.17 provides the final safety analysis report (FSAR) supplement for the Reactor Vessel Surveillance Program. The U.S. Nuclear Regulatory Commission (NRC or the staff) reviewed this FSAR supplement description of the program against the recommended description for this type of program as described in NUREG-1800, "Standard Review Plan for License Renewal," Revision 2 (SRP-LR), Table 3.0-1 and noted several inconsistencies between the two descriptions.

Issue:

SRP-LR Table 3.0-1 recommends that the FSAR supplement provide that (1) any future tests of surveillance capsules will meet the requirements of American Society for Testing and Materials (ASTM) Standard Practice E 185-82, "Conducting Surveillance Tests for Light-Water Cooled Nuclear Power Reactor Vessels;" (2) any changes to the capsule withdrawal schedule will be submitted to the NRC for approval; and (3) untested capsules placed in storage will be maintained for future reinsertion. The staff noted that these attributes of the program have been adequately described in LRA Section B2.1.17, which addresses the applicant's program elements; however they are not speci'fically addressed in the LRA Section A 1.17 FSAR supplement for the program. Therefore, the staff noted that the licensing basis for this program for the period of extended operation may not be adequate if the applicant does not incorporate this information in its FSAR supplement.

Reguest:

Taking into consideration the issue above, the staff requests that the applicant revise the FSAR supplement for this program so that it is consistent with the recommended description for this program in SRP-LR Table 3.0-1.

RAI 82.1.20-1 a

Background:

By letter dated August 21, 2012, in response to RAI B2.1.20-1, the applicant amended LRA Sections B2.1.20 and A 1.20 to correct the number of in-scope socket welds for its "One-Time Inspection of ASME Code Class 1 Small-Bore Piping" AMP. The program includes a volumetric or opportunistic destructive examination of socket welds to identify potential cracking. The GALL Report AMP states that when opportunistic destructive examinations are used for socket welds, the applicant may take credit for each weld destructively examined as equivalent to having volumetrically examined two welds. The staff noted that the revised LRA is not clear on how each destructive test will be credited.

-2 Issue:

The staff noted that the revised LRA is not clear on how each destructive examination will be credited. Specifically, if the applicant chooses to perform opportunistic destructive examinations on socket welds in lieu of volumetric examinations, it is not clear to the staff whether the applicant will adhere to the recommendation of the GALL Report AMP.

Request:

Revise LRA Sections B2.1.20 and A 1.20, to be specific about when and if opportunistic destructive examinations are used by the AMP, how each opportunistic destructive test on a socket weld will be credited in lieu of volumetric examinations. If the revised LRA Sections B2.1.20 and A.1.20 are not consistent with the GALL Report AMP program, provide justification for the exception.

RAI B2.1.14-5a

Background:

In RAI B2.1.14-5 issued by letter dated July 5, 2012, the staff requested additional information regarding operating experience related to the water-based fire protection system piping. The response was received by letter dated August 6,2012.

The response to part (a) stated that there were two instances of leakage from the buried high-density polyethylene (HOPE) piping that was installed in 2007 which were attributed to poor fusion during installation. Although this is out-of-scope piping, similar replacements were performed in the in-scope essential service water (ESW) system. The staff lacks sufficient information to conclude that poor fusion failures will not occur on the in-scope ESW piping given that the fire water system failures did not reveal themselves for at least three months and upwards of 46 months after installation.

The response to part (b) stated that there have been no failures in the fire protection system piping related to internal aging effects since 2001. However, the staff noted that the fire main flow test failure in 2004 was attributed to internal corrosion, and that after chemical cleaning of the system in 2006, additional failures of the fire main flow test have occurred in 2009 and 2011 for which accumulation of corrosion products has not been eliminated as a cause. Although contributing factors to the flow test failures have been identified and the procedure has been revised in order to verify operability of the system, the test results indicate that the condition of the fire main is degrading and a cause has not been identified. It is not clear to the staff what caused the extensive buildup of corrosion products and tuberculation that contributed to the failed fire main flow tests and whether the existing flow testing frequency is adequate to identify degradation prior to loss of intended function given the repeat failures at the existing frequency.

The staff also noted that there were four instances in which buried piping experienced leakage but the cause could not be determined because the piping was abandoned in place or isolated.

As a result of two of these cases, the entire length of piping between the plant and the training center was abandoned in place and new HOPE piping was installed. The RAI response stated

- 3 that these leaks occurred just after chemical cleaning of the system, yet the summary table in the RAI response did not attribute any leakage to internal aging effects. In addition, for at least one of the cases where external corrosion was listed as the cause of the failure, the staff reviewed pictures of the failed piping during the audit which indicated that internal corrosion was also present in the piping and could have contributed to the failure. It is unclear to the staff whether the summary table included descriptions of all the degradation mechanisms observed for each instance, regardless of failure mechanism, and whether the applicant has adequately evaluated whether loss of material due to corrosion is contributing to leakage from the system.

The response to part (c) stated that microbial corrosion, coatings, and pipe wall thickness will be used to project the condition of the fire protection system piping through the period of extended operation. However, the microbiologically influenced corrosion (MIC) sampling plan, and nondestructive examination (NDE) testing plan are not credited for aging management of the fire protection system for license renewal.

The response to part (d) stated that the internal surfaces of fire protection system piping are monitored using the Raw Water Systems Control Program and the Raw Water Predictive Maintenance Program. The RAI response stated that the Raw Water Predictive Maintenance Program includes opportunistic visual inspections to ensure the structural integrity of the piping.

However, the activities in the Raw Water Systems Control and Raw Water Maintenance Programs, including water treatment activities, are not credited for aging management of the fire protection system for license renewal. It is unclear to the staff how opportunistic visual inspections of the fire water system piping are adequate to ensure the structural integrity of the piping given the unknown cause of past piping failures and failed flow tests.

The response to part (e) stated that the Fire Water System Program will be enhanced to include a sampling plan for performing NDE testing to determine general wall thickness with locations selected based on susceptible locations and information from inspections and chemistry sampling. The staff noted that the enhancement states that the program will be enhanced to include non-intrusive pipe wall thickness examinations or internal visual inspections prior to the period of extended operation and at 1O-year intervals thereafter. The enhancement does not discuss the basis for where inspections will be conducted or the basis for the 10-year frequency.

From the information requested, there does not appear to be a corrosion rate established for the fire protection system piping and failures have occurred much more frequently than 10 years apart.

Issue:

The staff lacks sufficient information to conclude that the activities in the Fire Water Program are adequate to manage aging for the fire protection system piping during the period of extended operation.

Request:

a) State the basis for why the inspections being conducted in accordance with the Buried and Underground Piping and Tanks Program will be sufficient to detect poor fusion of in-scope ESW piping, or state the basis for why this failure mechanism is not applicable to the piping.

-4 b) State the cause of the extensive buildup of non-microbial corrosion products and tuberculation that contributed to the failed fire main flow tests and leakage that developed after chemical cleaning; the basis for acceptability of the existing fire main flow testing frequency for identifying degradation prior to loss of intended function; and the basis for why loss of material due to corrosion is not contributing to leakage from the system.

c) Include the MIC sampling plan, and NDE testing plan in the Fire Water System Program description and Final Safety Analysis Report (FSAR) Supplement for license renewal, or provide alternative provisions to project the condition of the fire water system components during the period of extended operation.

d) State the basis for why opportunistic visual inspections are adequate to ensure the structural integrity of the system given the unknown cause of past piping failures and failed flow tests.

Include the activities which are being used to ensure the structural integrity of the fire water system in the Raw Water Systems Control and Raw Water Maintenance Programs, including water treatment activities, in the Fire Water System Program description and FSAR Supplement for license renewal, or provide alternative provisions to ensure the structural integrity of the fire water system components.

e) State the basis for the pipe wall thickness inspection frequency, inspection sample size, and inspection location selection criteria; and include this information in the Fire Water System Program and FSAR Supplement.

ML12270A147 *concurrence via e-mail OFFICE PM:DLRlRPB1 LA: DLRlRPB2* BC:DLRlRPB1 PM:DLRlRPB1 NAME SCuadrado IKing DMorey SCuadrado DATE 10/01/12 9127112 10/02/12 10/03/12

Letter to A. Heflin from S. Cuadrado DeJesus dated, October 3, 2012

SUBJECT:

REQUEST FOR ADDITIONAL INFORMATION FOR THE REVIEW OF THE CALLAWAY PLANT, UNIT 1, LICENSE RENEWAL APPLICATION, SET 14 (TAC NO. ME7708)

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