ML111260284
| ML111260284 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 05/11/2011 |
| From: | Michael Mahoney Plant Licensing Branch III |
| To: | |
| mahoney, m NRR/DORL/LPLIII-2 415-3867 | |
| Shared Package | |
| ML111260313 | List: |
| References | |
| TAC ME6057 | |
| Download: ML111260284 (21) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555*0001 11ay 11. 7,011 LICENSEE:
FIRSTENERGY NUCLEAR OPERATING COMPANY (FENOC)
FACILITY:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1
SUBJECT:
SUMMARY
OF MAY 2, 2011, MEETING WITH FENOC ON PROPOSED LICENSE AMENDMENT REQUEST TO DELETE TECHNICAL SPECIFICATION 5.5.8G (TAC NO. ME6057)
On May 2, 2011, a Category 1 public meeting was held between the U.S. Nuclear Regulatory Commission (NRC) and representatives of FENOC (the licensee) at NRC Headquarters, One White Flint North, 11555 Rockville Pike, Rockville, Maryland. The purpose of the meeting was to discuss a proposed license amendment request (LAR) to delete Davis-Besse Nuclear Power Station (DBNPS) Technical Specification (TS) 5.5.8.g, Steam Generator (SG) Program special visual inspections." A list of attendees is provided as Enclosure 1.
The licensee presented information (See Enclosure 2). The license provided details on the proposed LAR to delete TS 5.5.8.g which states:
Special visual inspections: Visual inspections of the secured internal auxiliary feedwater header, header to the shroud attachment welds, and the external head thermal sleeves shall be performed on each SG through the auxiliary feedwater injection penetrations. These inspections shall be performed during the third period of each to year Inservice Inspection Interval (lSI).
The license provided background of the original design for the auxiliary feedwater header (AFWH). The license provided information on damage of the AFWH and SG tubes in 1982 and resolution to the damage which included repairs and modifications (secured and abandoned-in place), which the NRC approved in a safety evaluation (SE) dated August 20, 1982. The license described license amendment 62, (SE dated September 30, 1983), which added special visual and eddy current inspections requirements into the TS. FENOC proposed the removal of TS 5.5.8g predicated on historically acceptable visual inspections and eddy current inspections and evaluation of changes to operational conditions. The license stated that eddy current testing will continue to be performed in accordance with TS 5.5.8.d.5. The licensee discussed a regulatory evaluation of the proposed change. The license also noted that there are no precedents to this proposed LAR.
The NRC staff discussed with FENOC regarding alternative ways to complete the required inspections. The NRC staff queried FENOC about the details of the 1982 damage and details of the modifications. The NRC staff asked FENOC if there were any other plants which have seen similar damage. FENOC responded that Oconee Unit 3 and Rancho Seco had similar damage but did not require similar changes to their TS at DBNPS. The NRC staff recommended that FENOC address in the LAR the following areas of interest:
-2
- Review the Oconee Unit 3 inspection results;
- Materials of construction for the repairs (gusset plates and welds);
- Review alternative inspection methods;
- Quality/Capability of the visual inspections Contingency plans if there is a delay in the newSGs;
- Information regarding plugging/stabilization of tubes in the periphery;
- Details on the extent of damage from the 1982 event;
- Dose and cost information for performing the special visual inspections;
- Actions taken if the AFWH to tube gap changes from eddy current inspections (possible new TS requirement).
It was also recommend that FENOC provide copies of material references to the NRC, so the information is readily available to the NRC staff for review. FENOC acknowledged these areas of interest and informed the NRC staff of the intent to submit this LAR to the NRC in June of 2011.
No decisions were made at this meeting. Members of the public were not in attendance. Public Meeting Feedback forms were not received.
Please direct any inquiries to me at 301-415-3867, or michael.mahoney@nrc.
Michael Mahoney, Project Man r
Plant Licensing Branch 3-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosures:
- 1. List of Attendees
- 2. Licensee Handout cc w/encls: Distribution via Listserv
LIST OF ATTENDEES MAY 2,2011, MEETING WITH FIRSTENERGY NUCLEAR OPERATING COMPANY PROPOSED LICENSE AMENDMENT REqUEST TO DELETE TECHNICAL SPECIFICATION 5.5.8.g Name Organization I
~-1 Jake Zimmerman NRR Ken Karwoski NRR Andrew Johnson NRR Shaun Anderson NRR Tom Lentz FENOC AI Wise FENOC
~-
Phil Lashley FENOC Trent Henline FENOC
~-
Luke Twarek FENOC Cal Heintz FENOC Emmett Murphy NRR I
~-
FENOC Representatives
- Tom Lentz, Manager - Fleet Licensing
- AI Wise, Manager - Technical Services Engineering
- Phil Lashley, Supervisor - Fleet Licensing
- Trent Henline, Supervisor - Engineering Programs
- Luke Twarek, Program Engineer
- Cal Heintz, Licensing Engineer
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Davis-Besse Nuclear Power Station (DBNPS) Technical Specification 5.5.8.g states:
"Special visual inspections: Visual inspections of the secured internal auxiliary feedwater header, header to shroud attachment welds, and the external header thermal sleeves shall be performed on each SG through the auxiliary feedwater injection penetrations. These inspections shall be performed during the third period of each 10 year Inservice Inspection Interval (lSI)."
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Internal Auxiliary Feedwater Header (AFWH):
- Originally a part of the auxiliary feedwater system
- Internal to both steam generators (SGs)
- Consists of a rectangular-shaped flow channel which encircles the steam generator tube bundle
- Functioned to uniformly distribute auxiliary feedwater flow inside the steam generators
- Both are currently secured and abandoned in-place
- Inspection accessibility is limited; requires external feedwater header and SG upper manway cover removal
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections
. ONCE-THROUGH STEAM GENERATOR WITH INTERNAL* AUX. FEEDWATER HEADER Primary inlet nozzle.
Generator tu bes Upper tube sheet Auxiliary Baffle feedwater Alignment header Pins 11_--'; _'-_II
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TAB License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections TUee5 0/1 (}'- z.
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License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Auxiliary Feedwater Header and SG Tube Damage:
- During the 1982 refueling outage, eddy current inspections identified periphery SG tube damage
- Follow-up visual inspections identified that the AFWH in each steam generator was dislodged and deformed
- Event documented in licensee event report (LER)82-019
- Cause of damage was determined to be rapid condensation-induced high pressure differential
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Resolution of the 1982 Damage:
- Internal AFWHs were secured and abandoned in-place; secured with gusset plates and fillet welds
- The original auxiliary feedwater penetrations were blocked with blind flanges
- New external auxiliary feedwater header with eight new injection nozzles installed
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections NRC Involvement:
- NRC reviewed the proposed repairs and modifications pursuant to the requirements of 10 CFR 50.54(f)
- NRC determined:
Proposed repairs and modifications were adequate Acceptable for Davis-Besse to resume normal plant operations
- NRC documented their conclusions in a safety evaluation report dated August 20, 1982
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections License Amendment Request and Amendment 62:
- On January 1, 1983, a license application to add special visual and eddy current inspection requirements into the Technical Specifications was submitted Requested by the NRC Direct result of plant-specific 1982 event Driven by lim ited inspection capability
- On September 30, 1983, the NRC issued Amendment 62 to incorporate the special visual and eddy current inspection requirement into the Technical Specifications
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Proposed Technical Specification Change:
- FENOC proposes to remove TS 5.5.8.g predicated on:
Historically acceptable visual inspections Historically acceptable eddy current inspections Evaluation of changes to operational conditions
- Eddy current inspections will continue to be performed in accordance with TS 5.5.8.d.5
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Historically Acceptable Visual I nspections for SG 1-B:
II Five special visual inspections since 1983 II During the 1984 refueling outage, four small linear indications were identified on external header thermal sleeve no. 3 II Determined to be the result of inspection activities II Thermal sleeve was reworked and reinstalled II Since 1984, no recordable indications have been identified II Last special visual inspection was completed during the 2010 refueling outage No special visual inspections are required prior to the scheduled replacement of the steam generator in 2014
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Historically Acceptable Visual Inspections for SG 2-A:
Four special visual inspections since 1983 No recordable indications have been identified Last special visual inspection was complet~d during the 1998 refueling outage One remaining inspection-is required prior to the end of the current inservice inspection interval [September 20, 2012]
Scheduled during the spring 2012 refueling outage Steam generator 2-A is also scheduled for replacement in 2014
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Historically Acceptable Eddy Current Inspections:
- Inspections are completed on both steam generators
[1-B and 2-A] every refueling outage
- At least 150 inservice periphery tubes are inspected as a special interest group
- Determine existing internal AFWH to tube gaps
- Provides reasonable assurance the AFWH is not moving and is not a threat to any inservice steam generator tubes
- Inspection results indicate that no significant changes have occurred since the baseline AFWH to tube gap criteria was established [1983 refueling outage]
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Evaluation of Changes to Operational Conditions:
2007 turbine header pressure modification 10 PSIG increase Flow induced vibration change is negligible 2008 power uprate initiative Approximate 1.6 percent increase in reactor power Bounded by current analysis Evaluations concluded that these operational changes would not significantly impact the steam generators 2010 inspections validate the evaluations Special visual inspection of steam generator 1-B Eddy current inspections of steam generators 1-8 and 2-A
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Trend Summary:
- For both steam generators, past special visual inspections have confirmed that internal AFWH and external header thermal sleeve degradation has not occurred
- For both steam generators, past eddy current inspections have confirmed that AFWH to steam generator tube gap conditions have not significantly changed since 1983
- Acceptable inspection trends indicate that degradation is not expected to occur during the short remaining service life of the steam generators
License Amendment Request (LAR)
Auxiliary Feedwater Header Special Visual Inspections Regulatory Evaluation:
- No Significant Hazards Consideration Analysis Does not involve a significant increase in the probability or consequences of an accident previously evaluated Does not create the possibility of a new or different kind of accident from any accident previously evaluated Does not involve a significant reduction in margin of safety
PKG ML111260313 Meeting Notice ML111080690 M l' ummary ML111260284 eemg S OFFICE DORULPL3-2/PM DORULPL3-2/LA DORULPL3-2/BC NAME MMahoney SRohrer RCarlson DATE 5/11/11 5/11111 5/11/11