ML18096A823
| ML18096A823 | |
| Person / Time | |
|---|---|
| Site: | Salem  |
| Issue date: | 07/07/1992 |
| From: | Gray E, Patnaik P NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML18096A820 | List: |
| References | |
| 50-272-92-08, 50-272-92-8, NUDOCS 9207160163 | |
| Download: ML18096A823 (7) | |
See also: IR 05000272/1992008
Text
REPORT NO.
U. S. NUCLEAR REGULATORY COMMISSION
REGION I
50-272/92-08
DOCKET NO.
50-272
LICENSE NO.
LICENSEE:
Public Service Electric and Gas Co.
P.O. Box 236
Hancocks Bridge, New Jersey 08038
FACILITY NAME:
Salem Nuclear Generating Station, Unit 1
INSPECTION AT:
Hancocks Bridge, New Jersey
INSPECTION DATES:
May 26-29, 1992
Inspector:
~ Patna.lk, Reactor Engirieer
Materials Section, Engineering Branch,
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A pproved by:
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E. Harold Gray, Chief, Materials Section,
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date
Areas Inspected: Review of program and sarnple inspection data on the inservice inspection,
the eddy current examination of steam generator tubes and the erosion/corrosion monitoring
of high energy piping during the tenth refueling outage of Salem Unit 1.
Results: The inservice inspection program and the eddy current examination program
reviewed for the tenth refueling outage of Salem Unit 1 complied with the applicable code
and the regulatory requirements. A review of sample inspection data on the above was
satisfactory. In the area of erosion/corrosion monitoring, the selection of components and
measurement of wall thickness for erosion were considered to be acceptable. However, the
licensee's disposition of degraded components found during examination of the feedwater
system lacked proper evaluation and was non-conservative. The licensee dispositioned
components that were below the code minimum wall with an evaluation that a predicted wall
thickness by the next refueling outage will be greater than a calculated wall thickness solely
based on operating pressure but not other loads of the design code. The disposition violates
the requirement of the design code ANSI B.31.1 referenced in the FSAR and hence
constitutes a deviation to the FSAR.
9207160163 920708
ADOCK 05000272
Q
2
1.0
INSERVICE INSPECTION osn (INSPECTION PROCEDURE 73753)
1.1
Scope
lnservice inspection by ultrasonic, magnetic particle, liquid penetrant and visual examinations
is performed to ensure integrity of the reactor coolant pressure boundaries.
An inservice
inspection is mandated by the ASME Boiler and Pressure Vessel Code,Section XI and is
essential to promote public health and safety.
1. 2
Findings
During the tenth refueling outage of Salem Unit 1, Public Service Electric and Gas (PSE&G)
conducted an inservice inspection in accordance with the ASME Code Section XI, 1983 edition
including the summer 1983 addendum. The current refueling outage is the first scheduled outage
of the second period of the second ten-year interval. The inservice inspection was conducted
during the outage on the following components or systems.
Reactor coolant pump bolts
Pressurizer and pressurizer relief nozzle
Pressurizer relief system
Pressurizer spray
Reactor coolant piping
Residual heat removal piping
Safety injection piping
Main steam piping
Containment spray piping
No. 12 steam generator transition cone
Chemical and volume control system
3
A review of inservice inspection data indicated .that the following welds had indications that
needed resolution.
Pressurizer Relief System Weld No. 6-PR-1103, 12-inch Elbow to Flange.
Liquid penetrant examination revealed one indication which exceeded the code allowable
dimension. The indication was removed by flapping. Subsequent ultrasonic and liquid
penetrant examination of the weld revealed no recordable indication.
Safety Injection System Weld No. 6-SJ-1141, Reducer to Elbow.
Liquid penetrant examination revealed one indication which exceeded the code allowable
dimension. This indication was removed by light grinding. subsequent reexamination
revealed no recordable indication.
The ultrasonic indications were related to the
geometry of the weld root.
Main Steam System Weld No. 34-MS-2121-2, Isolation Valve to Piping.
Magnetic particle examination revealed an indication which exceeded the code allowable
dimension. The indication was in the fusion line of the valve body. The indication was
ground out with adequate remaining wall thickness of the valve. Reexamination of the
ground area revealed no recordable indication.
Safety Injection System Weld No. 2-SJ-2160, Elbow to Pipe.
Liquid penetrant examination revealed two linear indications 3/8 and 9/32 inch in length.
Reexamination after surface preparation revealed no recordable indication.
The resolution of above indications were considered to be satisfactory.
The licensee functionally tested sixteen snubbers. There were no failures. The data on snubber
testing were reviewed against the requirements of the following procedures and found to be in
compliance.
Procedure SH.SS-IS.ZZ-0106(Q), Rev. 0, Hydraulic, Mechanical Snubber and
Compensating Strut functional bench testing.
Procedure SH.SS-IS-ZZ-0104, Rev. 2, Visual examination of Mechanical Snubbers,
Hydraulic Snubbers and Compensating Struts.
A review of above procedures indicated that the procedures provided clear and adequate direction
to perform required testing .
4
The licensee's program for contro.l of non-conformances on ISI findings was reviewed against
the procedure NC-NA-AP-ZZ-0020(0), Rev. 1. A sample of non-conformance reports (NCRs)
was reviewed to verify identification of problems and disposition of non-conformances. Within
the scope of the review, the NCRs. addressed non-conformances effectively and provided
necessary control in preventing plant restart until non-destructive examination findings were
resolved.
1 . 3
Conclusion
Based on review of examination records, procedures and interviews with personnel, the ISI
program at Salem Unit 1 was found to meet the requirements of the applicable code and the NRC
regulations.
2.0
STEAM GENERATOR EDDY CURRENT EXAMINATION
2.1
Scope
The steam generator eddy current examination is performed to ensure integrity of steam generator
tubes and hence the reactor coolant pressure boundary. This examination was performed during
the tenth refueling outage to comply with the requirements of the Technical Specification.
2.2
Finding
The licensee performed full length bobbin coil examinations on twenty percent of all inservice
tubes in each steam generator. Also, rotating pancake coil (RPC) examinations were performed
on twenty percent of tubes in the hot leg of the tube sheet and at support plate locations in each
steam generator. The RPC examinations at the tube sheet were performed to satisfy concern for
the explosive tube expansion in the tube sheet for Westinghouse Model 51 steam generators such
as those at Salem. Examination at support plates was conducted at dent locations previously
identified.
As a result of the examination, one tube in No. 12 steam generator, three tubes in No. 13 steam
generator and two tubes in No. 14 steam generator were plugged. The plugs were made of
Inconel 690 and were mechanically plugged.
The licensee conducted a helium leak test of No. 11 steam generator to locate the source of the
primary to secondary leak observed during operation. As a result of helium leak testing, three
plugs explosively plugged during manufacture were mechanically replugged.
5
2. 3
Conclusion
For those.areas inspected, the eddy current examination and plugging of defective tubes, met
the requirements of the Technical Specification. The conduct of helium leak test to detect
source of primary to secondary leak is an innovative approach. The licensee was
conservative in plugging three tubes in Nos. 13 and 14 steam generators with indications
ranging from 35 to 38 percent, which is indicative of maintaining the plant in a safe
condition.
3.0
EROSION/CORROSION MONITORING PROGRAM (INSPECTION
PROCEDURE 49001)
3.1
Scope
The monitoring of erosion/corrosion in high energy piping is important to maintain structural
integrity of piping and components. During this inspection, the licensee's program for
selection of components susceptible to. erosion/corrosion and the data obtained from wall
thickness measurements were reviewed.
3. 2
Findings
The licensee's selection of corhponents susceptible to erosion/corrosion in high energy piping
was based on use of the EPRI CHEC program along with engineering judgement. The
licensee identified a total of 300 components in high energy systems being susceptible to
erosion/corrosion. However, froni a ranking of components based oh CHEC results, 52
components were selected for thickness measurement. The result of the thickness
measurement indicated that eleven components in the feedwater system outside containment
were below the design minimum wall thickness per the ANSI B3 l. l Code. The licensee
expanded the scope of examination and measured the wall thickness of eleven additional
components. Based on the minimum wall thickness being within applicable code
requirements, these were found to be acceptable.
A review of licensee's disposition of the' first sample of 11 components that were below the
design minimum wall indicated that the licensee accepted the components "as is" until the
next refueling outage based on a faulty engineering evaluation that a predicted wall thickness
of the components by the next refueling outage is greater than a calculated minimum wall to
resisl operating pressure but not other loads of the design code.
The acceptance evaluation by use of minimum wall thickness based on operating pressure and
temperature alone is non-conservative and differs from the requirement of the applicable
ANSI 831. 1 Code referenced in the FSAR for the design of the system. Hence, the
disposition of the components constitutes a deviation to the FSAR. (50-272/92-08-01)
6
Subsequent to the exit meeting, PSE&G has directed significant effort toward establishing the
extent of problems with dispositions to erosion/corrosion affected high energy plant piping.
Resolution and corrective actions to the findings have been in progress by PSE&G and monitored
by NRC through direct inspection, telephone conferences and management meetings.
3. 4
Conclusion
The acceptance evaluation by the licensee for degraded components due to erosion violated the
requirements of the design code and is considered to be a significant weakness in the program.
However, the selection of components and ultrasonic measuremel)ts for wall thinning met
industry standards.
4.0
ENTRANCE AND EXIT MEETINGS
Members of the licensee's management were informed Of the scope and the purpose of this
inspection at the entrance meeting that took place on May 26, 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 May 29, 1992.
A list of attendees at the exit meeting is
appended to this report as Attachment 1 .
ATTACHMENT 1
LIST OF ATTENDEES
Public Service Electric & Gas Company
C. A. Vondra, General Manager, Salem Operation
J. A. Ranalli, Manager, Nuclear Mechanical Engineering
D. LaMastra, Supervisor, Nuclear Mechanical Engineering
G. Owen, Site Services
K. Pike, technical support
D. W. Kline, Supervisor, Nuclear Mechanical Engineering
D. C. Namit, Nuclear Mechanical Engineering
M. Alpaugh, Licensing
C. J. Conner, ISI
P. J. Duca, Jr., Delmarva Power, Salem Site Representative
R. W. Oakes, Atlantic Electric, Site Representative
U.S. Nuclear Regulatory Commission
B. Westreich, Resident Inspector
P. Patnaik, Reactor Engineer