ML20205D790
| ML20205D790 | |
| Person / Time | |
|---|---|
| Issue date: | 03/25/1987 |
| From: | Rosenthal J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | Conway W, Hardwick R INSTITUTE OF NUCLEAR POWER OPERATIONS, VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.) |
| References | |
| NUDOCS 8703300486 | |
| Download: ML20205D790 (7) | |
Text
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MAR 2 5 1987 Mr. R. J. Hardwick, Jr.
Manager Nuclear Programs and Licensing Virginia Electric and Power Company P.O. Box 26666 One James River Plaza Richmond, Virginia 23261
Dear Mr. Hardwick:
SUBJECT:
IE DRAFT BULLETIN: THINNING 0F PIPE WALLS IN NUCLEAR POWER PLANTS The enclosed draft bulletin is being considered for issuance to all nuclear power reactor facilities holding an operating license or construction perrait.
We would appreciate your comments and those of NUMARC on the draft bulletin and any input on the anticipated burden the bulletin may impose on nuclear utilities.
Any comments received prior to April 6, 1987 will be considered in the prepara-tion of the final draft to be presented to the Committee to Review Generic Requirements.
If you have any questions regarding this matter, please feel free to contact me or Mr. Henry Bailey of my staff.
I can be reached at (301) 492-4193 and Henry at (301) 492-9006.
Sincerely, jVWhW &Jood by Jack E. Rosenthal, Chief Events Analysis Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
Enclosure:
IE draft bulletin Distribution:
i.
DEFER R/F EAB R/F JRosenthal RBaer EJordan HBailey RWoodruff
- SEE PREVIOUS CONCURRENCES
- EAB:DEPER:IE
- EAB:DEPER:IE HBailey:md JRosenthal 3/ /87 3/ /87 8703300486 870325 C
Mr. R. J. Hardwick, Jr.
Manager Nuclear Programs and Licensing Virginia Electric and Power Company P.O. Box 26666 One James River Plaza Richmond, Virginia 23261
Dear Mr. Hardwick:
SUBJECT:
IE DRAFT BULLETIN: THINNING 0F PIPE WALLS IN NUCLEAR POWER PLANTS The enclosed draft bulletin is being considered for issuance to all nuclear power reactor facilities holding an operating license or construction permit.
We would appreciate your comments and those of NUMARC on the draft bulletin and any input on the anticipated burden the bulletin may impose on nuclear utilities.
Any comments received prior to April 6, 1987 will be considered in the prepara-tion of the final draft to be presented to the Committee to Review Generic Requirements.
If you have any questions regarding this matter, please feel free to contact me or Mr. Henry Bailey of my staff.
I can be reached at.(301) 492-4193 and Henry at (301) 492-9006.
Sincerely, Jack E. Rosenthal, Chief Events Analysis Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
Enclosure:
IE draft bulletin Distribution:
PDR DCS DEPER R/F EAB R/F JRosenthal RBaer EJordan HBailey RWoodruff PER:IE 8:DE ER:IE Bailey:md JRosenthal 3g7 3g/87
s MAR 25 15 Nil Mr. W. F. Conway Group Vice President Industry and Government Relations
~ Institute for Nuclear Power Operations 1100 Circle 75 Parkway Atlanta, Georgia 30339
Dear Mr. Conway:
SUBJECT:
IE DRAFT BULLETIN: THINNING 0F PIPE WALLS IN NUCLEAR POWER PLANTS The enclosed draft bulletin is being considered for issuance to all nuclear power reactor facilities holding an operating license or construction permit.
We would appreciate your comments on the draft bulletin and any input on the anticipated burden the bulletin may impose on nuclear utilities. Any comments received prior to April 6,1987 will be considered in the preparation of the final draft to be presented to the Committee to Review Generic Requirements.
If you have any questions regarding this matter, please feel free to contact me or Mr. Henry Bailey of my staff.
I can be reached at (301) 492-4193 and Henry at (301) 492-9006.
Sincerely, Orig 1nef skeM Dr Jack E. Rosenthal, Chief Events Analysis Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
Enclosure:
IE draft bulletin Di tribution:
P CS DEFER R/F EAB R/F JRosenthal RBaer EJordan HBailey RWoodruff
- SEE PREVIOUS CONCURRENCE r
- EAB:DEPER:IE EAB:DEPER:IE HBailey:md JRosenthal 3/ /87 3/ /87
Mr. W. F. Conway Group Vice President Industry and Government Relations Institute for Nuclear Power Operations 1100 Circle 75 Parkway Atlanta, Georgia 30339
Dear Mr. Conway:
SUBJECT:
IE DRAFT BULLETIN: THINNING OF PIPE WALLS IN NUCLEAR POWER PLANTS The enclosed draft bulletin is being considered for issuance to all nuclear power reactor facilities holding an operating license or con ruction permit.
We would appreciate your comments on the draft bulletin a any input on the anticipated burden the bulletin may impose on nuclear ut ities. Any comments received prior to April 6,1987 will be considered in the preparation of the final draft to be presented to the Committee to Review Generic Requirements.
If you have any questions regarding this matter, please feel free to contact me or Mr. Henry Bailey of my staff.
I can be reached at (301) 492-4193 and Henry at (301) 492-9006.
Sincerely, Jack E. Rosenthal, Chief Events Analysis Branch Division of Emergency Preparedness and Engineering Response Office of Inspection and Enforcement
Enclosure:
IE draft bulletin Distribution:
PDR DCS DEPER R/F EAB R/F JRosenthal RBaer EJordan HBailey RWoodruff l
R:IE EAB:DEPER:IE RBailey:md JRosenthal 3/g87 3/ /87 l
l L
"I"'T SSINS No.: 6820 4f bj EHCLOSURE 1 OMB No.: 3150-0011 IEB 87-XX UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, DC 20555 March XX, 1987 IE BULLETIN NO. 87-XX: THINNING OF PIPE WALLS IN NUCLEAR POWER PLANTS Addressees:
All licensees for nuclear power plants holding an operating license or a j
construction permit.
Purpose:
The purpose of this bulletin is to request that licensees submit information concerning their programs for monitoring the thickness of carbon steel pipe walls in nuclear power plants.
Description of Circumstances:
Unit 2 at the Surry Power Station experienced a catastrophic failure of a main feedwater pipe which resulted in fatal burns to four workers, on December 9, 1986. This event was reported in IE Information Notice (IN)86-106, "Feedwater 1
line Break," on December 16, 1986, and IN 86-106, Supplement 1, on February 13, l
1987. The licensee submitted Licensee Event Report (LER) 86-020-00 on January 8,1987 for Docket 50-281 and an updated report, LER 86-020-01 on January 14, 1987. The updated LER had attached a comprehensive report entitled "Surry Unit 2 Reactor Trip and Feedwater Pipe Failure Report." The findings of NRC's augmented inspection team were issued of February 10, 1987 in IE Inspection Report Nos. 50-280/86-42 and 50-281/86-42.
Investigation of the accident and examination of data by the licensee, NRC, and others led to the conclusion that failure of the piping was caused by erosion / corrosion of the pipe wall. Although erosion / corrosion pipe failures have occurred in other systems, particularly in small diameter piping in two-phase systems and in water systems containing suspended solids, there have been no previously reported failures in large diameter systems containing high-purity water. Consistent with industry practice, the licensee did not have in place an inspection procedure for examining the thickness of the walls of feedwater and condensate piping.
2 Main feedwater systems, as well as other power conversion systems, are important to safety.
Failures of active components in these systems, for example, valves or pumps, can result in undesirable challenges to plant safety systems which are required for safe shutdown of the plant and accident mitiga-tion. Nevertheless, such failures are anticipated, and plants are designed to cope with them.
Piping failures in the secondary system are analyzed as t
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Page 2 of 3 either infrequent or limiting faults, depending on the extent of the failure.
Implicit in this classification is that piping will be maintained within allowable thickness values.
Failure of such high-energy fluid systems can result in challenges to the operating staff and the plant which are more complex and severe than simple anticipated operational occurrences because of potential systems interactions of high-energy steam and water with other systems such as electrical distribution, fire protection and security systems.
Further, some power conversion systems are safety related. Also, some safety systems at nuclear power plants are fabricated from carbon steel, (e.g., RHR, CCW). Licensees' counitments for the functional capability of these important-to-safety and safety-related systems are reflected in FSARs and are a part of the licensing basis for the facility.
Actions Requested:
Within 45 days from the receipt of this bulletin, licensees are requested to provide for safety-related systems fabricated from carbon steel, and for important-to-safety systems fabricated from carbon steel such as condensate, feedwater, steam, and connected high-energy piping (single phase and two phase), the following information:
1.
Identify the codes or standards to which the piping was designed and fabricated.
2.
Describe the scope and extent of your programs for ensuring that pipe wall thicknesses are not reduced below the minimum allowable thickness.
Include in the description the criteria that you have established for a.
selecting points at which to make thickness measurements b,
determining how frequently to make thickness measurements 3.
For liquid phase systems, state specifically whether the following factors have been included in criteria for selecting points at which to monitor piping thickness (Item 2a):
a.
piping material (low carbon steel) b.
piping configuration (fittings less than 10 pipe diameters apart) c.
pH of water in the system (pH less than 9.2) d.
system temperature (between 195 and 440* F) e.
fluid bulk velocity (greater than 10 feet /second) f.
oxygen content in the system (oxygen content less than 600 ppb) 4.
Summarize the results of inspections which have discovered or searched for pipe wall thinning and identify all items chronologically.
a.
Briefly describe the inspection program and whether it was intended to measure wall thickness or whether an incidental result.
b.
Describe what p ng was examined and how (e.g., describe the inspec-tion instrument
, test method, reference thickness, locations
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'L Page 3?cf 2-examined, means for locating measurement point (s) in sub,equent inspections).
Report thickness measurement results and note'which were identified c.
as unacceptable and why.
1 e d.
Describe actions taken or planned for piping with nonconformfes, wall thickness. Include any failure analysis results and material s
replacement or repair.
5.
Describe any plans or schedules foredeveleping or revising the present program based on the experience at Surry.
The written report shall be submitted to the appropriate; Regicnai Administrator under oath or affirmation under provisions _of Section 182a, At-)mic Energy Act of 1954, as amended.
In addition, the original copy of the cover letter and a-ctpy
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of the report shall be transmitted to the U.S. Nuclear Regulatory Comnission, Document Control Desk, Washington, D.C. 20555 for reproduction and distribution.
This request for information was approved by the Office of Management and Budget under blanket clearance number 3150-0011. Comments on burden and duplication may be directed to the Office of Management and Budget Reports q
Management, Room 3208, New Executive Office Building.. Washington, D.C. 20503.
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NRC intends to sumarize the information collected under this bulletin and
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study it to help determine if additional actions"are required by the staff and/or industry. The information will be, analyzed and shared with ir.dusfry.
If you have questions regarding this mhtte, please contact the Regionti Administrator of the appropriate NRC ragiorel office or one of the technical contacts listed below.
l l
James M. Taylor, Director Office of Inspection and Enforcement l
Technical Contacts: Henry BJ1!ey, IE Roger Woodruff, IE l
(301) 492-9006 (301) 492-7205 Attachments:
1.
IE IN 86-106 2.
IE IN 86-106, Supplement 2 3.
List of Recently Issued IE Bulletins
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