ML18064A804
| ML18064A804 | |
| Person / Time | |
|---|---|
| Site: | Palisades  |
| Issue date: | 06/15/1995 |
| From: | Haas K CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9506280141 | |
| Download: ML18064A804 (4) | |
Text
{{#Wiki_filter:'~. *- consumers Power POWERING MICHIGAN-S PllOGRES5 Palisades Nuclear Plant: 27780 Blue Star Memorial Highway, Covert, Ml 49043 June 15, 1995 U S Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 DOCKET 50-255 - LICENSE DPR PALISADES PLANT KurtM. Haas Plant Safety and Licensing Director PROJECT PLAN FOR ADDRESSING ALLOY 600 ISSUES - REVISED INSPECTION SCOPE In a letter dated February 27, 1995, we submitted our Project Plan for Addressing Alloy 600 Issues at the Palisades Plant. Section 3.0 of the plan contained a description of the NOE inspections that we had planned for the 1995 refueling outage. The NRC's April 13, 1995 letter described additional information needed to complete review of the project plan. Our letter dated April 24, 1995 provided the requested information. The 1995 refueling outage began on May 22, 1995 and the Alloy 600 NOE inspecti.ons have begun. No primary water stress corrosion cracking (PWSCC) has been identified from the inspections completed to date. We have, however, exceeded our radiation dose predictions for the inspection portion of the project by a factor of approximately four or five. This has resulted in a re-evaluation of the scope of inspections we will be completing during this refueling outage and the determination that some of the inspections will not be completed. Because the original inspection dose estimates were underestimated and our desire to complete as many inspections for PWSCC as possible was high, a large number of inspections were planned covering components of all levels of PWSCC susceptibility. Section 3.0 "Project Description", of the Project Plan in Table 1, "PWSCC Inspection Prioritization Index for Palisades" divides the 251 Alloy 60.0 penetration nozzles and safe ends in the primary coolant system into either susceptibility Grouping I, I I, or II I. On a re 1 at i ve sea 1 e, Group I represents those nozzles or safe ends that are most susceptible to PWSCC, Group II represents those nozzles or safe ends that have a moderate susceptibility to PWSCC, and Group III represents those nozzles and safe ends that are least susceptible to PWSCC. The Group I components are generally related to the pressurizer and one hot leg penetration. The Group II components are also divided into upper and lower susceptibility groupings with the components generally related to the reactor vessel head, one pressurizer, 9506280141 950615 PDR ADOCK 05000255 P PDR ) I I A URS ENERGY COMPANY -vvvvt)
one hot leg and one cold leg penetration being grouped in the upper susceptibility range in Group II. The lower Group II susceptibility grouping includes components from three main areas (i.e. hot leg, cold leg and ~eactor head} as does the Group III components. 2 The original plan included visual inspection of all 251 locations in the PCS, ultrasonic inspection of 79 welds, 77 dye penetrant tests of welds, and 8 eddy current tests of the reactor vessel head instrument nozzles. The original dose esti.mate for completing all of this work for the 1995.refueling outage was 24.0 REM. The part of the dose attributable to the planned tnspections was 3.5 REM. Most of the remainder of the dose estimated for the project is due to the power operated relief valve nozzle replacement, scaffolding, weld pr~Rarations for examinations, reactor vessel head insulation replacement and the mechanical stress improvement activities. We have accumulated approximately 12.5 REM with the inspections completed so far, and are estimating that an additional 4-5 REM will be accumulated during completion of our revised inspection scope. With some other emergent work identified with the project and because of the increased inspection doses, our estimate for completing the revised scope of Alloy 600 work is now approximately 40 REM. The revised scope of inspections that will be completed as part of the Alloy 600 1995 refueling outage inspections are a visual inspection of all 251 Alloy 600 PCS locations, 27 ultrasonic inspections, 61 dye penetrant inspections, and a eddy current inspections of the reactor vessel head incore nozzles.
- This revised inspection scope:
(1} will include ~11 examinations needed to support NRC committed actions and appropriate operability conclusions, (2) will assure that the most susceptible Group I components and the more susceptible Group II components will receive either an ultrasonic or a dye penetrant inspection along with a visual inspection, and' (3} will also assure that all 251 alloy 600 locations in the PCS will receive a visual inspection. The examinations that have been dropped from the outage inspection scope are 52 ultrasonic inspections and 16 PT inspections, all of which were associated with Group II lower susceptible and Group III lowest susceptible components. A listing of those inspections deleted is contained in Attachment 1.
SUMMARY
OF COMMITMENTS Th1 s l etie*r cont a fos 'no**new commitments and makes no' changes to existing commitments. I Kurt M Haas Plant Safety and Licensing Director CC Administrator, Region III, USNRC NRR Project Manager, USNRC NRC Resident Inspector - Palisades Attachment
ATTACHMENT 1 CONSUMERS POWER COMPANY PALISADES PLANT DOCKET 50-255 PROJECT PLAN FOR ADDRESSING ALLOY 600 ISSUES REVISED INSPECTION SCOPE - UT AND PT INSPECTIONS THAT WILL NOT BE PERFORMED 1 Page
~ UT AND PT INSPECTIONS THAT WILL NOT BE PERFORMED The following UT inspections will not be completed during the 1995 refueling outage as originally planned as noted in the Alloy 600 Project Plan Revision 1 which was transmitted to the NRC in our letter dated February 27, 1995. Hot Leg Inspections Pressure and sampling shop welds Pressure and. sampling field welds One hot leg drain shop weld Cold Leg Inspections Two charging nozzles Two spray nozzles Eight pressure and sampling nozzles .Four loop drain nozzles Four safety injection nozzles Total Number of UT weld examinations reduced 10 UT weld exams 1 UT weld exam 1 UT weld exam 4 UT weld exams .4 UT weld exams 16 UT weld exams 8 UT weld exams 8 UT weld exams from original scope 52 The following PT inspections will not be. completed during the 1995 refueling outage as originally planned as noted in the Alloy 600 Project Plan Revision 1 which was transmitted to the.NRC in a letter dated February 27, 1995. Cold Leg Inspections IB c.old leg IA.co*l d leg 2A c.old leg i nje.ct ion spray and safety injection 4.PT weld exams charging and safety injecti-0n 4 PT weld exams charging, spray and safety 28 cold leg safety injection -... :r.otaJ=,number... of.-JH weld,.~examinatJons.reduced.. _ from ori g.i:na,l scope
- 6 PT examinations 2 PT examinations 16
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