ML14178A410
| ML14178A410 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 11/16/1993 |
| From: | Blake J, Chou R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML14178A408 | List: |
| References | |
| 50-261-93-25, NUDOCS 9312140077 | |
| Download: ML14178A410 (9) | |
See also: IR 05000261/1993025
Text
UNITED STATES
0
NUCLEAR REGULATORY COMMISSION
REGION II
o0
101 MARIETTA STREET, N.W., SUITE 2900
ATLANTA, GEORGIA 30323-0199
Report No.:
50-261/93-25
Licensee: Carolina Power and Light Company
P. 0. Box 1551
Raleigh, NC 27602
Docket No.:
50-261
License No.:
Facility Name: H. B. Robinson
Inspection Conducted:
October 18 -
22, 1993
Inspector:
/L/1), /
,
7?,
R. C. Chou
Date Signed
Approved by:
/
/
/ 3
.J.
B1 *-,Chief
Date Signed
Mat ia nd Processes Section
En ne
ing Branch
Di ision of Reactor safety
SUMMARY
Scope:
This routine, announced inspection was conducted in the areas of piping system
modifications and Technical Specification snubber inspections.
Results:
In the areas inspected, two violations were identified. No deviations were
identified. The violations are failure to verify eight missing welds in field
for two supports and the purchase order for the material installed for a
support by the quality control (QC) inspectors and construction foremen. The
licensee has weaknesses in the review of the completed products performed by
the QC inspectors and foremen.
9312140077 931117
PDR ADOCK 05000261
G
REPORT DETAILS
@1.
Persons Contacted
License Employees
- R. L. Barnett, Project Management Manager
- D. Baur, Regulatory Affairs Specialist
- R. Beverage, Quality Control (QC) Supervisor
- T. Cleary, Technical Support Manager
D. Crook, Regulatory Affairs Senior Specialist
- J. M. Curley, Engineering Support Manager
- C. R. Dietz, Vice President on site
- D. Dyksterhouse, Project Manager - Civil
- W. Farmer, Inservice Inspection (ISI) Manager
- M. Pearson, Plant Manager
- C. S. Olexik, Assessment Section Manager
- D. Waters, Regulatory Affairs Manager
J. Noble, Modification Coordinator
Other licensee employees contacted during this inspection included
craftsmen, engineers, mechanics, technicians, and administrative persons.
Other Organizations
T. Roland, Modification Implementation Unit (MIU) Coordinator
NRC Resident Inspector
- C. Ogle, Resident Inspector
- Attended Exit interview
2. Piping System Modification
The licensee had completed several modifications in piping systems before
and during the current refueling outage. A major modification is Mod.
No. 1104 which includes the modification of about 150 pipe supports in
several piping systems in the Containment, Reactor Auxiliary, and Turbine
Buildings.
The inspector randomly selected 18 pipe supports with modifications
completed before or during this refueling outage. The 18 pipe supports,
in safety related systems and Non-Safety related systems with seismic
design, were all in large bore piping. They involved Auxiliary Cooling
System, Chemical and Volume Control System, Fire Protection System, and
Safety Injection System in the pipe alley of Reactor Auxiliary Building
and for Auxiliary Feedwater System (portions of supports inspected are in
Non-Safety related system with seismic design) and Feedwater System in
the Turbine Building. The licensee treated the non-safety related but
seismically qualified piping systems as safety related piping systems
2
since those non-safety related but seismically qualified systems must be
prevented from falling and damaging the safety related piping systems,
structures, or equipment during earthquakes.
The walkdown reinspection was completed with assistance from the
licensee's engineers and QC inspector who was also qualified as a welding
inspector. The major acceptance criteria and procedures used by the
licensee's QC inspectors for the modifications are listed below:
-
Specification No. CPL-HBR2-C-011, Civil Inspection
Requirements
-
Modification Implementation Program MIP-200, Installation and
Inspection of Equipment, Supports, and Components
-
Corporate Weld Manual (CWM)
-
Maintenance Management Procedure MMM-028, Control of Field
Issued Material
The supports were partially reinspected, particularly for the current
modifications, against the detail drawings and procedures. They were
checked for configuration, identification, fastener/anchor installation,
anchor size, anchor type, anchor marking, anchor edge distance, base
plate size and thickness, plate warpage, member size, weld sizes,
component identification numbers, component sizes and settings, dimen
sions, oxidation accumulation, maintenance, welder identification,
purchase order, mark on materials, and damage protection. The supports
reinspected during the current inspection are listed below:
Table 1
Walkdown Reinspection Supports
Item No. Support No.
Rev. No. System
Bldg
Discrepancies/
Comments
1
AC-6-4055
A
2
lB
CVC
Two additional
attachments were
not shown in the
drawings.
3
A
CVC
4
A
5
A
6
SI-20-237
OA
3
7
SI-20-1200
2A
8
WD-1-185
A
WD
9
FW-1-6226
A
10
FW-1-7234
A
11
FW-1-7241
A
12
FW-6B-73
2A
Four welds are
missing in two
base plates
between the stiff
ener plates and
base plates.
13
FW-6C-109
2A
Same as FW-6B-73
14
FW-7-33A
A
Construction ID
SS-2232
15
FW-7-33C
A
The purchase order
PO 710701 Item 2
was found in east
pipe clamps. The
document was
signed off as
purchase order PO
7G0046, Item 1.
Construction ID
SS-2233.
16
FW-7-40A
A
Construction ID
SS-2234
17
FW-7-54B
A
18
FW-7-54C
A
Notes:
1. Abbreviation Symbols:
a. AC
-
Auxiliary Coolant System
b. CVC -
Chemical and Volume Control System
c. FP
-
Fire Protection System
d.
-
Safety Injection System
4
e. WD -
Waste Disposal System
f. AFW -
Auxiliary Feedwater System
g.
FW -
Feedwater System
h. RAB -
Reactor Auxiliary Building
i. TB -
Turbine Building
2. Item 14 FW-7-33A to Item 18 FW-7-54C are non-safety related but
seismically qualified supports.
Support AC-6-4055 required a partial penetration weld to connect a new
base plate to the existing base plate. Support CH-6-117 required a full
penetration weld to connect a new base plate to the existing base plate.
The inspector could not determine if those two new welds were full or
partial penetration welds by visual inspection since the new and existing
base plates had been painted.
Support WD-1-185 required a full penetration weld to connect two plates
in the air off walls or floors to restrain the pipe. The inspector could
see evidence of weld on both sides of the plate and therefore, concluded
that this weld connection was a full penetration weld even though the
plates were painted over.
Support CH-6-117 was found to have two additional attachments, a tube
track unistrut and an instrument support FI-60168, which were not shown
in the drawings. Prior to the modifications, the licensees design
engineers had requested field information and found that the two new
attachments added about 10 percent additional loads, but decided not to
include them in the analysis due to the relatively small addition. The
licensee's engineers recognized the mistake of not including those loads
in the analysis and agreed to revise the calculations and drawings to
include those additional supports.
Support SI-20-237 was found with Item 14, angle steel, shown on the wrong
side of Item 1 in the drawing. The licensee's engineers stated that they
had found this problem during their previous inspection and were in the
process of revising the drawings.
Supports FW-6B-73 and FW-6C-109 were found to have four welds missing in
each support between the connections of base plates and long stiffener
plates. The licensee's engineers stated that those missing welds were
part of modification for plant Mod. 988 during Refueling Outage 13 (the
last refueling outage). The design for that modification required those
welds. The QC documentation for support/restraining welding, the Seismic
Weld Data Report (SWDR) was signed off as having all required welds
complete. The SWDR used at that time does not delineate specific welds
inspected therefore the specific inspection of the weld in question can
not be identified. The licensee concluded that the installers did not
make the missing welds and the QC inspectors did not note that the welds
5
had not been made. The licensee's engineers re-reviewed the calculation
and concluded that the missing welds are not required, therefore, there
is no impact on the safety of the unit. The licensee will revise the
drawings to reflect the as-built weld configuration.
10 CFR 50, Appendix
B, Criteria X, requires that examinations, measurements, or tests of
material or products processed shall be performed for each work operation
where necessary to assure quality. Robinson Nuclear Plant Unit 2
Specification No. CPL-HBR2-C-011, Civil Inspection Requirements required,
at Section 6.2.3, welded connection, verify that welds are in accordance
with design documents. Section 9.0 of this specification and, at Section
3.2.2 of Attachment G, requires that when restraint sketches provide weld
information, size, type, length if any defect were detected they shall be
verified. Contrary to the above, four welds at each support were missing
in the field and were not noted by the installers and QC inspectors.
This missing weld problem is identified as Violation 50-261/93-25-01,
Missing Welds at Supports FW-6B-73 and FW-6C-109.
During the inspection, the inspector could not find the welder identifi
cation (ID)
number and material purchase order marked or stenciled in
half of the 10 sway struts inspected due to the combination of paint and
"light" marks. To show the welder ID and purchase order having been
marked in the installed materials, the licensee removed paint from four
sway strut supports. The welder ID and purchase order are required to be
marked by procedures. Support FW-7-33C also called SS-2233 was found to
have material purchase order PO-710701 marked in the pipe clamps in the
east side. The Installation Data Report (IDR) for Support No. SS-2233
(this is the construction identification number for the support in the
field) was signed off as PO-7G0046, Item 1 by the installer and verifier
(QC inspector) on September 22, 1993.
Per the purchase and warehouse procedures, the sway strut supports
normally consisting of end attachment, strut pipe and adjusters, and pipe
clamps, are purchased as an assembly, with the same purchase order, and
which were marked individually on the three parts by the Quality Assur
ance (QA) inspectors after the assembly had been received and accepted.
Therefore, the purchase order marked on the three parts of the installed
sway strut support No. FW-7-33C should be the same and as documented in
the IDR.
(Per construction coordinator, it is a normal process to
discard the entire assembly if part or portion of the assembly was
damaged or could not be repaired.) The materials installed with the
different purchase order without the approval from the supervisor and
without the document revision were unacceptable. The construction
foremen and the QC inspector apparently did not adequately review or
verify that the final installed products met the requirements and were as
received from the warehouse. There may have been some existing problems
between receiving the right materials and installing the wrong materials
without the notice of the construction foremen and QC inspectors. CP&L
Robinson Technical Specification in Section 6.5.1, Procedures, Tests, and
Experiments, requires that written procedures shall be established,
implemented, and maintained covering the activities recommended in
Appendix "A" of Regulatory Guide 1.33, Rev. 2, February 1978.
6
CP&L Robinson Maintenance Management Procedure No. MMM-028, Control of
Field Materials, requirements are as stated below:
Section 5.4.1.1 -
This number (purchase order number) is the pri
mary identification for traceability of most
material used.
Section 5.4.1.2 -
All identification transfer operations shall
include the transfer of this number (purchase
order number) unless authorized otherwise by
Maintenance or Modification Implementation Unit
(MIU) Supervision.
Section 5.9.2 -
Maintenance and MIU Supervision shall ensure
that the proper material is used and installa
tion documents are properly marked to indicate
the job on which the material was installed.
Contrary to the above, the purchase order number PO-710701, Item 2 at
pipe clamps installed in east side for Pipe Support FW-7-33C (Special
Support SS-2233) was different from the purchase order number PO-7G0046,
Item 1 for the material received from the warehouse. This problem is
identified as Violation 50-261/93-25-02, Material Purchase Order Differ
ences between the Field Installation and Documents for Support
FW-7-33C.
During the inspection in the Turbine Building area, the inspector noticed
that two anchor bolt nuts for support FW-6B-59 have gaps (no contact)
between the nuts and base plates. The licensee's engineers will issue a
nonconformance report to repair the gaps.
The inspectors asked the licensee's engineers about the current practice
for establishing hold points on welding. They provided an example
consisting of page 29 of Attachment 6, of IDR for construction of Support
ID SS-2232 (design drawing No. FW-7-33A). This page contained seven QC
hold points as indicated by the licensee hold point terminology. They
considered that each step requires QC to verify or sign on the document
as a hold point. Actually, some steps can be combined and signed at one
time because the succeeding step would not cover up and preclude inspec
tion of the previous step. Therefore, the actual hold point may be that
QC verifies and signs a couple of steps in the documents.
There were seven steps in this example for a weld inspection for the
connection between the cut end of a strut pipe and the adjuster. These
are:
1. Verify use of approved fixture and fixture number
2. Verify end preparation on extension piece (pipe)
3. Fit-up (including tack weld)
7
4. Surface inspection
5. Visual examination of root pass weld
6. Visual examination of final weld
7. Verify location of sight hole
The normal practice is that the above seven steps are combined into four
hold points as:
1. Hold point 1:
QC inspector will inspect steps 1 to 4 at same
time.
2. Hold point 2:
for step 5
3. Hold point 3:
for step 6
4. Hold point 4:
for step 7
The inspector did not see any problems for the above hold points and
signing off steps 1 to 4 in the same time for one hold point.
3. Snubber Inspection
All snubbers in safety-related systems, and non-safety related systems
required to protect safety-related systems, are required to be operable.
Technical Specification (TS) 4.13.1 requires 100 percent visual inspec
tion and ten percent functional testing of these snubbers during each
refueling outage. There are a total of 53 snubbers in Robinson plant and
most of them have been inspected during this refueling outage. Three
snubbers, No. 16, 32, and 36 had been found out of cold setting ranges
and were transferred to the engineering department for evaluation of
impact on the piping systems. The procedures used for snubber inspection
and reinstallation are listed below:
-
Engineering Surveillance Test Procedure EST-032, Visual Inspec
tion of Hydraulic and Mechanical Shock Suppressors,
Rev. 17.
-
CM-401, Removal and Reinstallation of Hydraulic and Mechanical
Shock Suppressors, Rev 13.
The inspector randomly selected seven snubbers for inspection. They are
Snubber Nos. 28, 29, 30, 31, 32, 33, and 34. All the snubbers inspected
are acceptable.
During the inspection, the inspector noticed that the current inspection
procedure did not require the snubber inspectors to inspect the support
ing structure for the snubbers and the gaps between washers and spherical
bearings at the both ends. The current practices are:
8
-
The snubber inspector will inspect the snubber from the end
bracket attachment point to the other attachment including the
base plate and anchor bolts if present. But the snubber
inspectors can go beyond and inspect the whole support if they
want. Inspection of the whole support is an option.
-
The snubber inspector will inspect the snubber rod paddle swing
angles to be within 5 degrees in each direction.
The above practices have deficiencies. If a snubber inspector just
inspects end-to-end of the snubber and is not required to inspect the
whole support structure for existing defects, the snubber may be in good
shape but the supporting structures might have defects which could not
support intended function of the snubber. The inspection of swing angle
within 5 degrees in each direction will prevent binding, but it could not
prevent excessive shifting or wear-out in the bearing and pin due to
vibrations or transients. A limited gap between washers and spherical
bearings at the both ends is required to prevent the excessive movement
and wear-out between the bearing and pin. The licensee's engineers
agreed to add the requirements in the next procedure revision to include
inspecting the whole support structure visually and establishing inspec
tion and acceptance criteria for the inspection of the gap between
washers and spherical bearings at the rod ends, near the brackets, or the
piston rod eyes, near the pipe clamps. No violations or deviations were
identified in this area.
4. Exit Interview
The inspection scope and results were summarized on October 22, 1993,
with those persons indicated in paragraph 1. The inspector described the
areas inspected and discussed in detail the inspection results listed
below. Proprietary information is not contained in this report.
Dissenting comments were not received from the licensee.
Violation 50-261/93-25-01, Missing Welds at Supports FW-6B-73 and
FW-6C-109.
Violation 50-261/93-25-02, Material Purchase Order Differences Between
the Field Installation and Documents for Support FW-7-33C.