ML16057A865

Upcoming Steam Generator Tube Inservice Inspection

ML16057A865
Person / Time
Site:	Davis Besse
Issue date:	02/29/2016
From:	Blake Purnell Plant Licensing Branch III
To:	Boles B FirstEnergy Nuclear Operating Co
Blake Purnell
References
CAC MF7398
Download: ML16057A865 (4)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 February 29, 2016 Mr. Brian D. Boles Site Vice President FirstEnergy Nuclear Operating Company Mail Stop A-DB-3080 5501 N. State Route 2 Oak Harbor, OH 43449-9760

SUBJECT:

DAVIS-BESSE NUCLEAR POWER STATION, UNIT NO. 1 - UPCOMING STEAM GENERATOR TUBE INSERVICE INSPECTION (CAC NO. MF7398)

Dear Mr. Boles:

lnservice inspections of steam generator (SG) tubes play a vital role in assuring SG tube integrity. A telephone conference call has been arranged with members of your staff to discuss the ongoing results of the SG tube inspections to be conducted during the upcoming Davis-Besse Nuclear Power Station, Unit No. 1, refueling outage. This call will occur after the majority of the tubes have been inspected, but before the SG inspection activities have been completed.

Enclosed is a list of discussion points to facilitate this call.

The U.S. Nuclear Regulatory Commission (NRC) staff will document a summary of the conference call, including any material that you provide to the NRC staff in support of the call.

If you have any questions, please contact me at (301) 415-1380.

Sincerely,

{Jh~

Blake Purnell, Project Manager Plant Licensing Branch 111-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346 cc: Distribution via Listserv

Enclosure:

Steam Generator Tube Inspection Discussion Points

STEAM GENERATOR TUBE INSPECTION DISCUSSION POINTS The following discussion points have been prepared to facilitate the conference call arranged with the FirstEnergy Nuclear Operating Company to discuss the results of the steam generator (SG) tube inspections at Davis-Besse Nuclear Power Station, Unit No. 1. The conference call will be conducted during the upcoming spring 2016 refueling outage towards the end of the planned SG tube inspections, but before the unit completes the inspections and repairs.

The U.S. Nuclear Regulatory Commission staff plans to document a summary of the conference call as well as any material that is provided in support of the call.

1. Discuss any trends in the amount of primary-to-secondary leakage observed during the recently completed cycle.

2. Discuss whether any secondary side pressure tests were performed during the outage and the associated results.

3. Discuss any exceptions taken to the industry guidelines.

4. For each steam generator, provide a description of the inspections performed including the areas examined and the probes used (e.g., dents/dings, sleeves, expansion-transition), the scope of the inspection (e.g., 100 percent of dents/dings greater than 5 volts and a 20 percent sample between 2 and 5 volts), and the expansion criteria.

5. For each area examined (e.g., tube supports, dent/dings, sleeves), provide a summary of the number of indications identified to-date for each degradation mode (e.g., number of circumferential primary water stress corrosion cracking indications at the expansion transition). For the most significant indications in each area, provide an estimate of the severity of the indication (e.g., provide the voltage, depth, and length of the indication). In particular, address whether tube integrity (structural and accident induced leakage integrity) was maintained during the previous operating cycle. In addition, discuss whether any location exhibited a degradation mode that had not previously been observed at this location at this unit (e.g., observed circumferential primary water stress corrosion cracking at the expansion transition for the first time at this unit).

6. Describe repair/plugging plans.

7. Describe in-situ pressure test and tube pull plans and results (as applicable and if available).

8. Discuss the following regarding loose parts:

a. what inspections are performed to detect loose parts

b. a description of any loose parts detected and their location within the SG (including the source or nature of the loose part, if known)

c. if the loose parts were removed from the SG

d. indications of tube damage associated with the loose parts

9. Discuss the scope and results of any secondary side inspection and maintenance activities (e.g., in-bundle visual inspections, feedring inspections, sludge lancing, assessing deposit loading).

10. Discuss any unexpected or unusual results.

11. Provide the schedule for steam generator-related activities during the remainder of the current outage.

ML16057A865 OFFICE DORL/LPL3-2/PM DORL/LPL3-2/LA DE/ESGB/BC DORL/LPL3-2/BC (A) DORL/LPL3-2/PM NAME BPurnell SRohrer GKulesa (AJohnson for) JPoole BPurnell DATE 2/29/16 2/29/16 2/29/16 2/29/16 2/29/16