ML20246M733
| ML20246M733 | |
| Person / Time | |
|---|---|
| Site: | Dresden, Browns Ferry, Saint Lucie, Oyster Creek, Duane Arnold, Fort Calhoun, 05000000 |
| Issue date: | 03/15/1989 |
| From: | Stuart C S.G. PINNEY CO. |
| To: | Rossi C Office of Nuclear Reactor Regulation |
| References | |
| IEIN-88-082, IEIN-88-82, NUDOCS 8903270233 | |
| Download: ML20246M733 (9) | |
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,, g, March 15, 1989 vuosawmn Esciseraisc E"ni"nIEs$IrN$*,$c.s.
Mr. Charles E. Rossi Director of' Operational Events Assessment
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Nuclear Regulatory-Commission Office of. Nuclear Reactor Regulation Washington, D.C.
20555
SUBJECT:
NRC Notice No. 88-82:
TORUS SHELLS WITH CORROSION AND DEGRADED COATINGS IN BWR CONTAINMENTS
Dear Mr. Rossi:
We have recently reviewed NRC Information Notice No.-88-82 and question the statements that divers can only detect general degradation and that -localized degradation can be-detected most effectively by draining and inspecting under dry conditions.
Historically, underwater inspection was performed by divers not-trained, qualified or certified to inspect, evaluate and document protective coatings.
These inspections were generally performed' with limited visibility due to sludge accumulation.
In 1984 S.
G.
Pinney & Associates, Inc. developed an underwater maintenance service for nuclear immersion areas.
This service includes. inspection by divers that are experienced, ANSI N 45.2.6 certified level II and III coating inspectors. Underwater services also incorporate desludging operations, detailed evaluation of pitting corrosion and spot repair of degraded areas.
This development is a cost effective method of detailed inspection and deficiency correction in immersion area protective coatings, eliminating the need for draining.
e903270233 s90315 gDR ADOCK0500g9 ENGINEERING, INSPECTION AND UNDERWATER SERVICES, SPECIALISTS IN CORROSION CONTROL
S.G. PINNEY & ASSOCIATES, INC.
PROFESSIONAL ENGINEERS 1
{
Mr. Charles E. Rossi
- March.15, 198P Page'2 Another benefit of underwater inspection and repair is reduced personnel radiation exposure which complies with ALARA requirements.
In our experience, personnel radiation accumulated dosage has been reduced - by a factor of 5 to 10, depending on conditions.
We have made detailed presentations on the subject of underwater coating inspection and repair for various groups of NRC personnel and will be pleased to provide additional presentations if requested.
Enclosed is a summary of relevant projects for various utilities by S.G. Pinney & Associates, Inc, which have successfully employed the underwater alternative to draining the vessel.
We feel that a supplement to Information Notice No. 88-82 should be issued ' identifying. current underwater technology as a viable.
cost effective method to detect coating degradation and pitting corrosion of nuclear immersion areas.
We offer our services to supply' current.information to support our position.
Please contact me at the Port St. Lucie office at (407)879-0574 for additional information.
Respectfully yours, Charles O.
Stuart Jr.
Manager of Quality Assurance
Enclosures:
As Stated CC:
S.
Pinney, J.
- Cavallo, C. Vallance, J. Oechsle 1
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S.G. PINNEY & ASSOCIATES, INC.
PROFESSIONAL ENGINEERS UNDERWATER ENGINEERING SERVICES Summary Of Relevant Projects Location &
Contact:
GPU Nuclear Corporation Oyster creek Nuclear Generating Station Edward O'Connor, 201-316-7245 Ron Miranda, 201-316-7372 Project Manager:
C. A. Vallance Project Description The removal of biological contamination and sludge from suppres-sion pool immersion areas and core and containment spray systems, coating inspection and coating repair.
Hydrogen Peroxide was injected into the suppression pool water to function as a cleaning agent. Concentration was naintained while divers vacuumed sludge and microorganisms from the wetted sur-faces. Following cleaning operations, inspection of the suppres-sion pool shell below the water line was conducted to determine coating condition. Over 2,000 coating defects up to one square foot in size were repaired using an underwater epoxy.
S.G. Pinney & Associates, Inc. designed and-installed a system housed in a 40' trailer to filter and process suppression pool l
water. The system was located outside secondary containment and allowed suppression pool water to be circulated through multi-stage filtration and ion exchange media and returned to the suppression pool. Rad waste was handled jointly by SGPAI and Chem-Nuclear Systems.
Underwater coat.ing inspection by ANSI N45.2 Level III and Level II coatings inspectors included detailed mapping of critical areas, coating adhesion tests using both knife peel tests and an elcometer adhesion tester, dry film thickness readings and exten-sive underwater photography and video. Pit depth measurements and ultrasonic wall thickness readings were taken.
Further evaluation of blistered coating was done by installing a vacuum box on the suppression pool shell and subjecting the coating to negative pressure. One foot square test areas were established in close proximity to allow detailed statistical evaluation of representative coating conditions over time.
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7 S.G. PINNEY & ASSOCIATES, INC.
l PROFESS!oNAL ENGINEERS tt
-Desludging, water processing, inspection and repair were com-I f>
pleted in 29 production days working around the clock seven days a week. A total of 6,765 man hours were spent in radiologically L
controlled areas with a total man-rem exposure of 12.6 rem.
Contact dose rates on the internal-suppression pool shell were reduced from 40 to 50 mr/hr to 1 to 2 mr/hr.
Engineering support provided included planning and scheduling, peroxide / coating repair material compatibility testing, DBA testing of underwater coating repair material, DBA testing of existing suppression pool coating system and engineering evalua-tion of coating condition.
Location.&
Contact:
Omaha'Public Power District Ft. Calhoun Station Bruce Shubert, 402-533-6830 Project Manager: C.A. Vallance Project Description inspection and' coating repair of the Safety Minor desludging, Injection Reactor Water Tank. The project included ultrasonic 4
thickness measurements of the tank liner, UT evaluation of suction penetration welds and inspection and repair of the liner coating.
Coating inspection was accomplished by removing small amounts of sludge from selected areas. Dry film thickness readings and pit depth measurements were taken. All inspections were conducted by ANSI N45.2 Leve) III and Level II coatings inspectors.
Localized areas of liner coating were repaired at sites where UT readings were taken and on isolated coating defects.
Inspection and coating repair was accomplished in 2 shifts by a four man crew. 55.33 RWP hours were logged with a total exposure of.290 man-rem.
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S.G. PINNEY & ASSOCI/>TES, INC.
PROFESSIONAL ENGINEERS Location'&
Contact:
' Tennessee Valley Authority Browns Ferry Nuclear' Plant Judi Border, 205-729-3182 Randy Widick, 205-729-3211 Project Manager:
C.O.
Stuart Project Description Mark I Desludge, inspect and repair coating in Unit 1 and Unit 2, BWR suppression pools. Wetted surfaces of suppression pools including downcomers, spargers, piping and structural supports were vacuumed to remove all visible signs of sludge.
Depth of inches with contact dose rates of 50 to sludge ranged from 1 to 4 1100 mr/hr.
Desludging and inspection required 40 production The days using a 7 man crew working single 10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> shifts.
desludging operation included the installation of a 600 gpm pump, high capacity filtration system and flexible ring header within the suppression pool Vessels.
Rad waste was handled jointly by S.
G. Pinney and Associates, Inc. & Browns Ferry. Contact dose rates were reduced to less than 5 mr/hr.
Underwater coating inspection by ANSI N45.2 Level III and Level II coatings inspectors included detailed mapping of critical areas, knife peel tests, dry film thickness readings and exten-sive underwater photography and video. Pit depth measurements were taken.
This Project also included sampling and analysis of biological contamination present in the suppression pools and condenser cooling water tunnels.
Over 10,000 coating defects were repaired underwater coating. repair procedures devel-and inspected using Pinney & Associates, Inc., Underwater Engineering oped by S.G.
Services. All topside and Underwater operations were documented on Video Tape. Inspection documentation included. video tape and 35mm still photography.
Total accumulated SGPAI crew exposure was less than 10 Man-Rem.
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A____-_____.-_____-___-
S.G. PINNEY & ASSOCIATES, INC.
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PaonssioNAL ENGINEERS Iowa Electric Light and Power Company Location &
Contact:
Duane Arnold Energy Center Surinder Shangari, 319-851-7453 Project Manager: C.O.
Stuart Project Description inspect and repair coating in Mark I BWR suppression
- Desludge, pool.
All wetted surfaces of suppression pool including downcomers, spargers, piping and structural supports were' vacuumed to remove Depth of sludge ranged from 1 to 4 all visible signs of sludge.
Desludging inches with contact dose rates of 300 to 500 mr/hr.
and inspection required 7 production days working single 10-hour The desludging operation included the installation of a 600 gpm pump, high capacity filtration system and flexible ringRad waste shifts.
header within the suppression pool Vessel.Inc. and DAEC. Contact jointly by S. G.
Pinney and Associates, dose rates were reduced to 12 to 25 mr/hr following cleaning.
Underwater coating inspection by ANSI N45.2 Level III and Level II coatings inspectors included detailed mapping of critical areas, knife peel tests, dry film thickness readings and exten-Pit depth measurements sive underwater photography and video.
were taken.
in Over 5,000 coating defects were repaired and inspected. ranging size from 1/4" dianeter to four square feet. All topside and Underwater operations were documented on Video Tape. Inspection documentation included video tape and 35mm still photography.
Total accumulated SGPAI/DAEC crew exposure was less than 24 Man-3,810 RWP man hours were expended.
Rem.
Engineering support provided included planning and scheduling, DBA testing of DBA testing of underwater coating repair material, existing tion of coating condition.
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S.G. PINNEY & ASSOCIATES, INC.
PROR3SloNAL ENGINEERS
.s.
Location &
Contact:
-Iowa Electric Light and Power Company-Duane Arnold Energy Center Surinder Shangari, 319-851-7453 Project Manager:
C.O.
Stuart ProjeJt Description Minor.desludging and inspection of Condensate Storage Tank.
An underwater coating insp<2ction by an ANSI N45.2 Level III in-spector was accomplished in one day by a three man team. Inspec-tion was documented by underwater photography.
Location &
Contact:
Commonwealth Edison Company Dresden Station Kevin Whitgrove 315-942-2920, Ext. 577 Project Manager: C.O.
Stuart Project Description Desludge and inspect two 250,000 gallon aluminum Condensate Storage. Tanks.
Each tank contained a sludge layer approximately 1 to 4 inches deep.
Contact-dose rates were 40 to 180 mr/hr After desludging, dose rates dropped to o to 5 mr/hr. Divers using underwater equipment installed within the tanks accomplished sludge vacuum removal, inspection, and photo documentation of both tanks in seven production days.
The crew consisted of four (4) men work-ing one ten hour shift per day.
The filtration system was de-Rad waste was signed and installed within the tanks by SGPAI.
Total accumu-handled jointly by SGPAI and Chem-Nuclear Systems.
lated SGPAI crew exposure was less than 4 Man-Rem.
l
)
Underwater inspection by ANSI N45.2 Level III and Level II coat-l ings_ inspectors included detailed mapping of critical areas, and i
extensive underwater photography and video. Pit depth measure-ments were taken, f
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S.G. PINNEY & ASSOCIATES, INC.
3 PROITSSIONAL ENGINEERS
-Location &
Contact:
Commonwealth Edison Company Dresden Station Kevin Whitgrove 815-942-2920, Ext. 577 Project Manager: J.T. Glanville Project Description Desludge Dryer / Separator Pit.
The station drained the Dryer / Separator pit and attempted to use operators employing hoses and squeegee type mops to direct sludge This method proved ineffective and initial exposures to drains.
The pit was subsequently flooded and vacuumed were very high.
The desludging opera-using an SGPAI system operated by 4 men.
tion was completed in 3 production days consisting of one 10 hour1.157407e-4 days <br />0.00278 hours <br />1.653439e-5 weeks <br />3.805e-6 months <br /> Total accumulated SGPAI crew exposure was less shift per day.
than.4 Man-Rem.
Location &
Contact:
Tennessee Valley Authority l
Browns Ferry Nuclear Plant Judi Border, 205-729-3182 Randy Widick, 205-729-3211 Project Manager:
C.O.
Stuart Project Description 350,000 Minor desludging, inspection, and coating repair of three This operation was similar to gallon Condensate Storage Tanks.the CST operation at Dresden Station bu Operations were completed in 15 produc-tion and coating repair.
tion days using a 4 man dive team working single shifts.
Desludging was accomplished using an " air lift" type vacuum system installed within the tanks. This type system is efficient and cost effective when selective cleaning is required.
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S.G. PINNEY & ASSOCIATES, INC.
l PROFESSIONAL ENGINEERS l
Location &
Contact:
Tennessee Valley Authority Browns Ferry Nuclear Plant Judi Border, 205-729-3182 Randy Widick, 205-729-3211 Project Manager: J.T. Glanville Project Description Valve inspection within the Suppression pool Ring Header.
This operation required divers to remove ECCS strainer's and
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enter the 30" diameter Ring Header.
Desludging operations were conducted inside the pipe to reduce dose rates and improve visi-bility. HPCI, RHR and core spray isolation valves were inspected
'i and findings were recorded by Underwater Video.
The inspection of five valves required entry in four separate locations and was completed in three days by a seven man crew working one ten hour j
shift per day. Upon completion of the ring header inspection, l
I leak checks blind flanges were installed on ECCS penetrations, conducted and strainers replaced.
Location &
Contact:
Florida Power and Light St. Lucie Nuclear Plant Jim Le Bleu, 407-694-3243 Project Manager:
C.
A. Vallance Project Description Minor desludging and inspection of two 350,000 Gallon Condensate Storage Tanks. Repaired two 6" diameter coating defects.
One hundred percent of the interior surface of the tanks includ-ing the vapor phase was inspected and coating defects were photo-Prior to coating repair, it was necessary to install graphed.
hydraulic jacks to raise an inlet pipe baffle plate allowing access to the repair area. Inspection & Coating repair was com-pleted in four ten hour shifts by a dive team of two men using SCUBA.
Underwater inspection by ANSI N45.2 Level III and Level II coat-ings inspectors included detailed mapping of critical areas, and extensive underwater photography. Pit depth measurements were taken on tank floor.
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