ML17005A328

Millstone Power Station, MPS2 EOC-23 and MPS3 EOC-17 Steam Generator Tube Inspection Reports - Requests for Additional Information (CAC Nos. MF8507 and MF8506)

ML17005A328
Person / Time
Site:	Millstone
Issue date:	01/05/2017
From:	Guzman R V Plant Licensing Branch 1
To:	Craft W D Dominion Nuclear Connecticut
Guzman R V
References
CAC MF8506, CAC MF8507
Download: ML17005A328 (2)

Text

From:Guzman, RichardTo:"wanda.d.craft@dom.com"Bcc:Guzman, Richard

Subject:

Millstone Power Station, MPS2 EOC-23 and MPS3 EOC-17 Steam Generator Tube Inspection Reports - Requestfor Additional Information (CAC Nos. MF8507 and MF8506)Date:Thursday, January 05, 2017 12:28:00 PMWanda,

The NRC staff has reviewed the information provided in the subject submittals dated December 14, 2015 (Agencywide Documents Access and Management System Accession No. ML15356A375) and August 2, 2016 (ADAMS Accession No. ML16222A351), and hasdetermined that additional information is needed to complete its review. Shown below arethe NRC staff's request for additional information (RAI) questions. Please provide your formal response by February 8, 2017. Please contact me if you have any questions.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Rich GuzmanSr. PM, Division Operator Reactor Licensing Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Office: O8E-10 l Phone: (301) 415-1030 Richard.Guzman@nrc.gov REQUEST FOR ADDITIONAL INFORMATIONEND OF CYCLE 23 STEAM GENERATOR TUBE INSPECTIONMILLSTONE POWER STATION, UNIT 2DOCKET NO. 50-336TAC NO. MF8507 By letter dated December 14, 2015 (Agencywide Documents Access and ManagementSystem Accession No. ML15356A375), Dominion Nuclear Connecticut, Inc., (DNC, the licensee) submitted information regarding the spring 2015 steam generator (SG) tube inspections performed at Millstone Power Station, Unit 2 during refueling outage 23 (RFO-23). In order to complete its review, the Nuclear Regulatory Commission staff requeststhe following additional information: 1. If any foreign objects were visually identified and left in service, please discusswhether an evaluation was performed to confirm that the foreign objects would not challenge the integrity of the steam generator tubes for the period of time until the next inspection.

2. Table 1 states that the "largest fan bar width" is 3.15 inches. Please discusswith further detail to which dimension this is referring (e.g., is this 3.15 inches the largest axial height that a tube is "crossed" by a fan bar?). Does each fan bar have a specific axial height at which it crosses over a tube (because of the angle at which the fan bar goes through the tube bundle)?

3. In the middle of page 2 of 11, it is stated that the visual examinations on theprimary side reveal no degradation. It is then indicated that secondary sidevisual examinations were performed in SG 1. At the end of the page, it indicates that the "results of the visual examinations performed were satisfactory." Please clarify whether this statement refers to the secondary-side visual examinations performed in SG 1. If not, please discuss the results of the steam drum visual examinations. ----------------------------------------------------------------------------------------------------------------------------------------------- REQUEST FOR ADDITIONAL INFORMATIONEND OF CYCLE 17 STEAM GENERATOR TUBE INSPECTIONMILLSTONE POWER STATION, UNIT 3DOCKET NO. 50-423TAC NO. MF8506 By letter dated August 2, 2016 (Agencywide Documents Access and Management SystemAccession No. ML16222A351), Dominion Nuclear Connecticut, Inc. (DNC, the licensee),submitted information summarizing the results of the spring 2016 steam generatorinspections performed at Millstone Power Station, Unit 3. These inspections wereperformed during refueling outage (RFO) 17. In order to complete its review, the U.S.Nuclear Regulatory Commission staff requests the following additional information: 1. Please discuss the results of the following secondary side inspections performedduring RFO 17:

a. The results of the post-sludge lancing visual examination of the top-of-tubesheet annulus and no-tube lane: If any foreign objects were visually identified and left in service, please discuss whether an evaluation was performed to confirm that the foreign objects would not challenge the integrity of the steam generator tubes for the period of time until the next inspection.

b. The results of the visual investigation of accessible locations having eddycurrent indications potentially related to foreign objects: If any foreign objects were visually identified and left in service, please discuss whether an evaluation was performed to confirm that the foreign objects would not challenge the integrity of the steam generator tubes for the period of time until the next inspection. c. The results of the secondary side upper internal examinations within SGB: was any degradation observed? 2. Please discuss whether any primary side inspections in the channel headwere performed (e.g., cladding, divider plate, plugs). If so, pleasediscuss the results.