IR 05000293/1987001
| ML20205C840 | |
| Person / Time | |
|---|---|
| Site: | Pilgrim |
| Issue date: | 02/19/1987 |
| From: | Gray E, Kaplan H, Strosnider J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | |
| Shared Package | |
| ML20205C763 | List: |
| References | |
| TASK-2.B.3, TASK-TM 50-293-87-01, 50-293-87-1, GL-84-23, NUDOCS 8703300275 | |
| Download: ML20205C840 (8) | |
Text
.
.
.
l l
U.S. NUCLEAR REGULATORY COMMISSION I
REGION I
Report No.
50-293/87-01 I
Docket No.
50-293 License No. OPR-35 Priority Category C
--
Licensee: Boston Edison Company M/C Nuclear 800 Boylston Street Boston, Massachusetts 02199 Facility Name:
Pilgrim Nuclear Generating Station Inspection At:
Plymouth, Massachusetts Inspection Conducted: January 5-9, 1987 l
l
!'
2./19 /87 Inspectors:
E. H. Gray, Lea rReactor Engineer date
- L. hzAm 2. - / 7#7 H. J. Kapl(n, Lead Reactor Engineer date A
Approved by:
.
2[td[87 f.R.Strosnider, Chief,Materialsand date V Processes Section, DRS, EB Inspection Summary:
Inspection on January 5-9, 1987 (Report No. 50-293/87-01).
Areas Inspected: A routine, unannounced inspection was conducted of activities related to service water system piping corrosion, the reactor coolant hydrogen injection system and reactor water level instrument modifications, magnetic particle material surface indications discovered during ISI, refuel bridge weld-ing, the post accident sampling system (PASS) and Quality Assurance-Quality Control interfaces between contractors and the licensee.
Results: Two violations were identified during inspection of the PASS system.
Also, an unresolved item was identified regarding structural steel welds on the refueling bridge that did not conform to AWS 01.1 code requirements and bolt stresses on refueling bridge cable takeup assemblies.
8703300275 870317 PDR ADOCK 05000293 G
.
.
DETAILS 1.
Persons Contacted Boston Edison Company (BECo)
M. Andrews, Mechanical Engineer (QC)
- M. Brosee, Maintenance Section Manager
- F. Famulari, QC Group Leader
- C, Grazio, Field Engineering Section Manager
- P. Hamilton, Senior Compliance Engineer R. Orkin, Senior QA Engineer J. Peters, Senior Construction Engineer B. Perkins, NDE Level III J. Seery, Technical Section Manager
- R. Sherry, Chief Maintenance Engineer B. Tucker, Project Manager
- E. Ziemianski, Management Services Section Manager General Electric (GE)
D. Tackett, Piping Consultant U.S. NRC
- J. Golla, Reactor Engineer
- J. Lyash, Resident Inspector
- M. McBride, Senior Resident Inspector
- Indicates those present at exit meeting of January 9, 1987.
2.
Service Water System BECo has experienced leakage problems since 1972 with th( carbon steel rubber lined portions of the Service Water System (5WS). The SWS pressure and temperature are 80 psi and 35 'F-100 *F respectively.
The wall thicknesses range between.312"
.375".
The SWS provides water to various auxiliary mechanical equipment throughout the turbine, auxiliary radwaste and fuel buildings.
The problem areas have generally been located in high turbulent areas such as elbows where lining failures have occurred because of poor bonding followed by apparent wastage (thinning) of the wall due to erosion.
During this time the system has been monitored by ultrasonic testing to determine wall thickness and repaired as required. Although small pieces of rubber apparently
.
dislodged, the licensee reported that they did not find any evidence of pieces of rubber in other component.
.
The inspector witnessed ultrasonic wall thickness measurements being taken during the present outage. The Inspector verified the accuracy of a
"Krautkramer" instrument with a curved calibration thickness wedge. The inspector observed that this instrument was utilized by the licensee for verification of instrument accuracy every half hour during the inspec-tion. The licensee also demonstrated that the instrument was capable of detecting 1/16" diameter pitting type defects using a calibration block.
The licensee reported no significant wall thinning in 400 ft. of piping except for a 2" x 4" area in an elbow (JF-29-81) which measured.150" compared to a specified minimum wall thickness of.170".
The licensee reported that an area (JF-29-22) which had been previously patched in October 1986 because of a pin hole leak was reinspected and showed no change in thickness. The inspector reviewed the ultrasonic inspection
' reports covering these areas and found them to be well documented with regard to location, measurements and calibration.
The licensee intends to replace Spool Pieces JF-29-81 & JF-29-22) with new rubber lined spool pieces during the present outage.
The licensee is planning to initiate an R&D program prior to startup to evaluate new materials such as Al Bronze, 70Ni-30Cu and titanium by placing test pieces in the traveling screen area for eventual replacement of the entire system. The licensee is planning to evaluate the ultrasonic data presently being obtained which will be used to program future inspections.
3.
Hydrogen (H ) Addition System and Crack Arrest Verification System (CAVS)
The licensee is in the process of installing a permanent hydrogen injec-tion system. The purpose of the system is to inject hydrogen into the reactor coolant via the feedwater system so as to lessen the susceptibi-lity of the stainless piping to intergranular stress corrosion cracking.
The hydrogen injection system consists of two parts; the primary system is the Electrolytic Hydrogen Water Chemistry System (HWCS), the secondary or backup system is the Extended Test System (ETS). The HWCS produces hydro-gen by electrolysing the water. Oxygen produced during the electrolysis is automatically injected into the off gas system to recombine with hydro-gen gas evacuated from the turbine condensers. The Extended Test System consists of nine flasks containing gaseous hydrogen as provided by Air Products and will be positioned away from the reactor building and used as a standby source of hydrogen. The HWCS system piping is designed and fabricated by GE in accordance with ANSI B31.1. The inspector reviewed the HWCS design and fabrication specification and found it to be detailed with respect to materials (316 stainless and carbon steel), fabrication, NDE and record requirements.
The inspector reviewed General Electric's Safety Analysis Report NEDC 3116-D and concluded that a thorough evaluation was performed to cover two major safety considerations resulting from the injection of hydrogen;
-
.
.
(1) the potential for forming explosive mixtures in various areas under certain conditions due to faulty equipment or human error, and (2) the increase of radioactive nitrogen-16 because of the formation of ammonia (NH,). The report covers both scenarios in detail.
In the case of the potential for forming explosive hydrogen mixtures the General Electric report concluded that under normal operation, transients, accidents and external events no consequence of HWCS would threaten plant or personnel safety.
In the case of the increase of nitrogen-16, the report concluded that it can be minimized by shielding and/or procedural controls. With respect to the former, shielding has been installed in the turbine build-ing during the present outage.
General Electric is also providing a Crack Arrest Verification (CAVS)
system which will contain laboratory cracked specimens that simulate the cracks found in the reactor vessel nozzle (N-2) thermal sleeve. The purpose of the CAV system is to monitor the effects of hydrogen injection on the pre-existing cracks in the test specimens.
The inspector witnessed welding of some of the HWCS spool pieces presently being fabricated by General Electric on site.
Specifications stated that all welds will be 100% visually inspected for quality and dimensional characteristics as required by 831.1.
No violations were identified.
4.
Reactor Water Level Instrument Line Modification The revision of the reactor water level instrumentation lines to meet the NRC Generic Letter 84-23 is shown on drawing SKI-8507-1.
In addition to rerouting these lines from nozzles 15A and ISB to minimize vertical drop within the drywell, the socket weld couplings and Inconel piping for 15A, 158, 16A and 168 are scheduled for replacement with butt welded piping per drawing E 232-346-5.
The inspector reviewed the above drawings, portions of the Safety Evalua-tion No.1880, Revision 2 and the project narrative for (PDC 85-07, Revision 2).
Installed portions of the 15A and ISB lines including the new core bore holes through the containment shield wall were observed.
Welder qualification records for the Bechtel welds were reviewed for comparison to the requirements of the ASME Code Section IX.
Field welds 1, 2, 3 and 4 and radiographs were examined for conformance to the ASME Code Section III and Section V requirements.
No violations were identified.
-
.
.
5.
Magnetic Particle Indications in MS, FW & RHR Systems During surface examination by the licensee of Main Steam, residual heat removal (RHR), and feed. water piping, magnetic particle indications were found in the base metal of nine welds.
The licensee reported that the indications in two of these areas were eliminated after removing approximately
.010 inches of material by light grinding; the indications in the remaining areas had not been explored at the time of this inspection. The inspector verified the licensee's results in the MS system by witnessing the licensee's reinspection of those areas which had been cleared by grinding (Weld 1-D-8-8062)
and two areas which had not been explored (Welds 1-A8 and 1-BR-1).
The NCR's for these weld areas were identified as 80-62 and 88-57 respectively.
,It is noted that it is not unexpected for indications of the type found in these carbon steel systems to have been detected during the current outage, since MT inspection was not required by the original design specification or previous ISI inspection.
Indications of this type are inherent in as-rolled products and are generally due to shallow surface imperfections such as laps or seams. Magnetic particle reinspection was performed by SNT-TCIA qualified personnel in accordance with Procedure 50-20.
No violations were identified.
6.
Refuel Bridge New and spent nuclear fuel are handled in movement to and from the reactor vessel by the fuel handling device supported by the plant refuel bridge.
The licensee is in the process of installing a new refuel bridge for which the structural steel portion is fabricated to the American Welding Society (AWS) D1.1 Code, 1980 Edition requirements. At the time of this inspection the refueling bridge was not classified as. safety related. However, the i
refuel bridge designation is in the process of being changed from not safety related to important to safety or safety related.
The inspector examined structural steel welds on the refuel bridge and found that the fit up requirement of part 3.3.1 of AWS D1.1 was not n.et
'
for some fillet welded structural components.
Some welds were found to have gaps exceeding 3/16" between the pieces welded together. Several other welds had gaps between 1/16" and 3/16" and were not increased in
'
size over the drawing dimension of 1/4" to compensate for the gap.
In summary, the inspector identified welds that did not conform to the AWS D1.1 code requirements.
Licensee inspection that followed confirmed the presence of welds not meeting AWS D1.1 and resulted in the issuance of the nonconformance Report NCR 87-01 by licensee QC.
Use of the refuel bridge was placed on hold pending engineering review disposition, and rework of the conditions not meeting AWS D1.1.
,
,
.. _... _.. _, _ _ _ _ _ -.
- _.. _..., _. _ _. _. _ _ _ _ _ __.____ _ __ _ _
. -,. _ _. _. -
_. __
.-
-
,_
.
.-
--
--. - -. -..
.-
.
-
-
.
.
.
During inspection of the refuel bridge, the inspector noted several cable take up assemblies cantilevered beyond the bridge structure and held in place by four bolts each. The inspector inquired if the manufacturer's calculation had confirmed the bolt stress for these components, however, no calculations were provided to the inspector.
The refuel bridge structure is an unresolved item with respect to closeout of the nonconformance with the AWS 01.1 fillet weld requirements and and licensee review of the above bolt stress calculations (50-293/87-01-01).
7.
QA Interfaces (General Electric, Bechtel and BECo.)
!
The inspector assessed the licensee's program for controlling work activi-ties being performed by Bechtel and General Electric during the current outage. Some of these activities include the Hydrogen Injection System and Reactor Water Level Instrument Line Modification.
Control is performed in accordance with the licensee's Contract Surveil-lance and Monitoring Program dated April 1, 1986 for Bechtel, and March 21, 1986 for General Electric.
The QC aspects of the program cover inspection of system processes and materials; the QA aspects cover document control, warehouse, and review of Work Plans and NCR's.
Information covering the QC and QA phase of the licensee's program is generated in reports, biweekly meetings, daily contact and annual audits.
On the basis of interviewing the responsible personnel and reviewing reports, the inspector concluded that Bechtel and General Electric's work activities were being effectively controlled by the licensee.
l 8.
Post Accident Sampling System (PASS)
Item IIB.3 of NUREG 0737, Clarification of TMI Action Plan Requirements,
requires a system be in place to sample reactor coolant and containment atmosphere promptly after an accident.
This system, the post accident sampling system was installed during the 1984 outage but was found to have through wall cracking during preoperational testing.
The inspector reviewed the report dated March 29, 1985 titled " Evaluation of Piping in the Containment Gas Sampling System." This report attributes the cracking to the presence of chlorides and sufficient temperature (over
,
300 *F) to cause stress corrosion cracking of the stainless steel piping.
The inspector reviewed procedure number 2.2.133 for the PASS system noting the requirement to maintain heat traced portions of the lines at
,
.
250 *F i 20 *F.
The system is not required to be in operation during i
the present refuel outage, but is required to be operational prior to j
plant startup.
i
!
i
.
.
.
.
.
..
.
.
Portions of the PASS were examined to evaluate conformance to the System Schematic drawing.
Instruments indicating heat tracing temperature dry-well H, and 0, contents were examined. Train "A" was operational, while train "B" was out of service for maintenance purposes. The inspector noted for train "A" that the thermocouple #5 heat tracing temperature was read-ing 354 F, and #6 was not indicating any temperature. This situation was brought to the attention of the licensee and an instrument and controls (I&C) technician was then observed during troubleshooting of the thermo-couples. Trouble shooting established the #5 thermocouple was not making proper electrical contact on the instrument cabinet. Thermocouple #6 upon correction of the electronic contact problem registered 364 *F, approximately 100 *F higher than allowed by procedure 2.2.133.
The inspector requested surveillance records of the PASS system temperature for the past two years to determine if heat tracing temperatures in excess of the design range were previously identified. He was advised that surveillance records of PASS system temperature readings were not maintained, and surveillances were not scheduled.
The cleaning of the contacts on the thermocouple electronic board was done with the eraser end of a pencil. The inspector requested to review the procedure controls on this practice and was pro-vided only with one procedure (3.M-2-11) that is not applicable to the PASS system. On this issue the inspector concluded that I&C technician's do clean electronic contacts with pencil erasers although this practice is not controlled by procedure and the chemistry of the erasers are not con-trolled or qualified with respect to potentially detrimental elements or compounds that might cause contact surface corrosion later.
In conclu-sion, in the PASS system inspection the following problem areas were observed.
1.
Surveillance of the PASS temperature was not scheduled and results if done were not available for review.
2.
Temperature measuring equipment was not fully operational.
One high (364 *F) heat trace temperature indication was observed.
3.
The cleaning of contacts on the electronic board for temperature measurement was done by a method not covered by procedure. The composition of the cleaning agent (pencil erasers) is not specified or controlled.
The significance of the heat tracing temperature surveillance and high temperature indication is that high temperature was a contributing factor to previous PASS pipe cracking and failure to track system temperature is a violation of 10 CFR 50 Appendix B, Criterion XVI with respect to taking actions to preclude repetition of a failure (293/87-01-02).
- The cleaning of the electronic contacts by pencil erasers in the PASS thermocouple control is not an activity documenteJ by procedure.
This item is unresolved pending verification that cleaning of electrical and electronic contacts is properly controlled and proper guidances is provided.
(293/87-01-03).
-
..
.
The inspector reviewed the Non-Destructive Examination Support Request number 86-05 which provide > for plans to eddy current examine portions of the PASS system piping during the current outage. The eddy current testing process is in the developmental stage for this application.
Successful completion of PASS piping eddy current examination could provide a basis to demonstrate PASS piping integrity.
9.
Extraction Steam Cascading Drains and Thickness Measurements The licensee is currently performing ultrasonic wall measurements in various high pressure non nuclear systems. The licensee reported no significant wall thinning in the main steam and cascading drains on the basis of measurements taken by General Electric using an automated
' ultrasonic system. The feedwater system is the next system to be checked.
The inspector reviewed the General Electric reports covering the cascading drain and found them to be complete.
10. Unresolved Items Unresolved items are matters about which more information is required in order to ascertain whether they are acceptable items, violations or deviations. An unresolved item disclosed during this inspection is discussed in Paragraph 6.
11.
Exit Interview An exit interview was held on January 9,1986 with members of the licen-see's staff as denoted in Paragraph 1.
The inspector discussed the scope and findings of the inspection. At no time during this inspection was written material provided to the licensee by the inspectors.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- -
-