IR 05000410/1992007
| ML17056B813 | |
| Person / Time | |
|---|---|
| Site: | Nine Mile Point  |
| Issue date: | 04/15/1992 |
| From: | Gray E, Patnaik P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML17056B812 | List: |
| References | |
| 50-410-92-07, 50-410-92-7, NUDOCS 9204280286 | |
| Download: ML17056B813 (14) | |
Text
U. S. NUCLEAR REGULATORY COMMISSION
REGION I
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nducted Nine Mile Point Nuclear Power tation nit 2 N
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~In actor:
P. Patnaik, Reactor Engineer Materials Section, Engineering Branch, DRS date Approved by: 6 E. Harold Gray, Ch',
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I the erosion/corrosion program for the high energy piping systems and a sample of nondestructive examination (NDE) inspection data collected during the March 1992 outage.
Results:
The inservice inspection program at Nine Mile Unit 2 met the requirements of the applicable code and the NRC regulations.
The licensee presently has an acceptable erosion/corrosion program.
However, the licensee stated that by the third refueling outage of Unit 2, the EPRI CHECMATE program which is more comprehensive than the existing program, would be implemented for selection of susceptible components for inspection and analysis of data.
'7204280286 9204i7 PDR ADDCK 05000410
1.0 n ervi In i n 7 7 1.1
~c The conduct of in'service inspection by ultrasonic, magnetic particle, liquid penetrant and visual examinations is performed to ensure integrity of the reactor coolant pressure boundary.
During this inspection, the ISI data for the second period of the first ten-year interval covering outages in October 1990 and in March 1992, were reviewed.
This review was performed to ascertain if the requirements of the applicable ASME Code Section XI and the Technical Specifications were met for plant components.
1.2 F~in din The licensee conducted the inservice inspection of the reactor coolant system in accordance with the ASME Code Section XI, 1983 edition including the summer 1983 addenda.
The outage plan for inservice inspection complied with the code requirements within the scope of the review.
The data pertaining to inservice inspection of the following welds were reviewed:
Weld Identification T
e of Examin tion Re;~ul g 2 ICS-57-06 SW016 (Reactor core isolation cooling system)
Ultrasonic and magnetic particle Acceptable 2 MSS-01-04-FW 012 (Main steam system)
Ultrasonic and magnetic particle
.
Acceptable 2 MSS-01-04.FW 302 2 MSS-01-04-FW 303 Interior of Reactor vessel Magnetic particle Magnetic particle Remote visual Acceptable Acceptable Acceptable The data on the following supports were reviewed:
Identification and xmin in
~eel 2 MSS-PSSP-390-A'1 (mechanical snubber)
Visual Acceptable after engineering evaluation
~:
2RHS-PSSP-0032-A2 (constant spring support)
Visual Unacceptable-Replaced component 2MSS-PSSH-004-A4 2MSS-PSSH-106-A4 (variable spring, dual can hanger)
Visual Visual Acceptable
'cceptable 2MSS-PSSH-006-A4 (constant spring support)
Visual Acceptable 2RHS-PSSH-052-A2 (variable spring)
Visual Acceptable 2RHS-PSSH-378-A2 (variable spring)
Visual Acceptable Non-conformance reports (NCR) or deficiency event reports (DER) were generated against discrepant items'r components and were sent to the design group in engineering for resolution.
The quality assurance group tracked
,DERs and ensured closeout prior to plant startup.
A review of a sample of the resolutions of indications from the outage found them to be satisfactory.
The following non-destructive examination (NDE) procedures were reviewed for compliance to applicable codes:
NDEP-UT6-02, Rev. 7, (Manual ultrasonic examination of austenitic steel piping and components welds)
NDEP-UT 6-03, Rev. 6, (Manual ultrasonic examination of austenitic piping welds)
NDEP-MT 4-00, Rev. 6, (Magnetic particle examination of welds)
A review of documentation on ultrasonic calibration standards (test blocks) for the reactor vessel bottom head, the recirculation outlet nozzle and the main steam piping indicated that the standards met the requirement of the ASME code.
Certifications of personnel performing ultrasonic and visual examinations were reviewed in accordance with the requirements of the procedure and the ASME code.
The certifications were readily available, complete and met the requirements of the procedure and the cod ~:
The inspector reviewed the report of quality assurance audit 90-171, dated October 18, 1990 and determined that the quality assurance coverage of the inservice inspection program was adequate.
The audit was thorough, indepth and there was no violation of the ASME Section XI Code requirements identified.
1.3 Q~n~lu ~in Based on a review of NDE records, procedures, and interviews with personnel, the inservice inspection program at Nine Mile Unit 2 was found to meet the requirements of the applicable code and the NRC regulations.
2.0 Er sion/ orr i n Pro ram 2.1
~co e The erosion/corrosion program was reviewed during this inspection.
Mitigation of erosion/corrosion in high energy piping is important at nuclear power plants to maintain structural integrity of piping and components.
During this inspection, licensee's criteria for selection of susceptible components for inspection, non-destructive examination of components for thickness measurement, erosion/corrosion data and their acceptance criteria were reviewed.
2.2
~Findin The selection of susceptible components to erosion/corrosion by the licensee was based on NUMARC and EPRI guidelines.
The parameters that affect erosion/corrosion are system pressure and temperature, fluid velocity, pH and oxygen, material type, geometry and percentage moisture.
Licensee's acceptance criteria for structural evaluation of erosion/corrosion thinning was based on EPRI guidelines (EPRI-NP-5911 SP, July 1988).
The thickness data pertaining to erosion/corrosion of the following components of high energy systems were reviewed to verify compliance to the licensee's program,
~:
Q~m~n~n Nominal
~W11 Program Actual Minimum Minimum Wall W~ll
-
~Mx Feedw er stem 24" dia. pipe 2.062 24" dia. pipe-do-24" dia. 900 elbow-do-24" dia. pipe-do-20"x24" expander 1.750 24" elbow 900 2.062 1.805-do-40-
-do-1.531 1.804 1.945 1.911 2.160 1.919 2.111 2.131 2.258 2. 196 2.754 2.305 2.807 2.786 Heater Drain Flange 0.375 12" dia. 900 elbow 0.687 0.328 0.601 0.502 0.801 0.566 1.125 Qgndeng<te 24" dia. 900 elbow 0.968 24"x20" reducer 0.812 0.847 0.711 0.927 1.266 0.968 1.434 x
Based on the licensee's acceptance criteria, as stated below, the data reviewed were determined to be acceptable.
Erosion/corrosion data is acceptable ifthe measured thickness is greater than 0.875 of the nominal thickness for forged, bored or cast components or the measured thickness is greater than the nominal thickness.
Erosion/corrosion data is considered unacceptable ifthe measured thickness is less than 0.20 of the nominal thickness and requires immediate repair or replacement.
Erosion/corrosion data between 0.20 of the nominal thickness and 0.875 of the nominal thickness requires evaluation to establish the proper disposition of the component.
The licensee's procedure for thickness measurement NDEP-UT-6.16, Rev. 4, utilizing digital measurement equipment was reviewed against industry standards and found to be satisfactor ~-
-
2.3 Qgn~~l<jinn The licensee presently has an erosion/corrosion program that willaddress the impact of flow assisted corrosion.
However, the licensee stated that by the third refueling outage of Unit 2, the EPRI CHECMATE program which is more comprehensive than the existing program would be implemented for selection of susceptible components for inspection and analysis of data.
En Exi M in Members of the licensee's management, engineering and technical staff were informed of the scope and the purpose of the inspection at the entrance meeting which took place on March 16, 1992.
The findings of the inspection were presented to and discussed with members of the licensee's management at the conclusion of the inspection on March 20, 1992.
A list of attendees of the exit meeting is attached to this report as Attachment ~:
'
ATl'ACHMENTI Nia ara'ohawk Power tion C. Beckham, Manager, Quality Assurance L. Dick, Supervisor, Quality Assurance T. Egan, ISEG Engineer J. Firlit; Vice President, Nuclear Generation M. McCormick, Plant Manager, Unit 2 J. Pavel, Licensing Engineer J. Swenszkowski, Quality Assurance Engineer N
rRe
mmi ion R. Laura, Resident Inspector B. Mattingly, Resident Inspector
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