ML19242A803
| ML19242A803 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 07/17/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Mary Johnson SOUTH CAROLINA ELECTRIC & GAS CO. |
| References | |
| NUDOCS 7908060356 | |
| Download: ML19242A803 (2) | |
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UNIT ED STATES
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JUL 17 879 In Reply Refer To RII:JPO 50-395 South Carolina Electric and Cas Conpany Atto:
M. C. Johnson, Vice President Special Services and Purchasing Post Office Box 764 Colu=bia, South Carolina 29218 Gestlemen:
This Information Notice is provided as an early notification of aIt is e No possibly significant matter.
the information for possible applicability to their facilities.
response is requested at this tine bowever licensees should be avsre i
1%'R 's that the ERC is evaluatics the issuance of a Bulletin to operat ng requesting information on previous inservice inspections of stagnant borated veter systems and requesting inspection of systera which i1 not been inspected recently.this matter, please contact the Director of the a Office.
Sincerely, F
% James P. O' Reil y Director
Enclosure:
1.
IE Information Notice Po. 79-19 2.
Listing of IE Information Fotices Issued in 1979 f'\\y,
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- 7. B. Conners, Jr.
Conners, Moore and Corber 1747. Pennsylvania Avenue, N.W.
Washington, D.C.
20006 A. A. Seith Quality Assurance Post Office Box 8 29065 Jenkinsville, South Carol.na O. S. Bradham, Manager Nuclear Operations Office Box 8 Post 29065 Jenkinsville, South Carolina (1l?ll I SI[y ~
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I UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF INSPECTION AND EhTORCEMENT WASHINGTON, D. C.
20555 July 17, 1979 IE Information Notice No. 79-19 PIPE CRACKS IN STACNANT BORATED WATER SYSTEMS AT PWR PLANTS Description of Circumstances:
During the period of November 1974 to February 1977 a number of cracking incidents have been experienced in safety-related stainless steel piping systems and portions of syste=s which contain oxygenated, stagnant or essentially Metallurgical investigations revealed these cracks stagnant borated water.
af fected zone of 8-inch to 10-inch type 304 material occurred in the veld heat (schedule 10 and 40), initiating on the piping 1.D. surf ace and propagating in either an intergranular or transgranular mode typical of Stress Ccrrosion Analysis indicated the probable corrodents to be chloride and oxygen Cracking.
Plants af fected up to this time were cont smination in the af f ected systems.
Arkansas Nuclear Unit I, R. E. Ginna, H.B. Robinson Unit 2, Crystal River Unit 3, The NRC issued Circular 76-06 San Onof re Unit 1, and Surry Units 1 and 2.
(copy attached) in view of the apparent generic nature of the problem.
I which began in February During the refueling outage of Three Mlle Island Unit of this year, visual inspections disclosed five (5) through-vall cracks at velds a weld in the decay heat fuel cooling system piping and one (1) at These cracks were found as a result of local boric acid build-in the spent This initial identification of removal system.
up and later confirmed by liquid penetrant tests.
(LER) dated May 16, cracking was reported to the NRC in a Licensee Event Report A preliminary metallurgical analysis was performed by the licensee on a 1979.
from the spent fuel cooling system.
section of cracked and leaking veld joint The conclusion of this analysis was that cracking was due to Intergranular Stress The cracking was Corrosion Cracking (IGSCC) originating >n the pipe I.D.
af f ected zone where the type 304 stainless steel is localized to the heat In addition to the main sensitized (precipitated carbides) during velding.
several locations in through-vall crack, incipient cracks were observed atasion area where a miniscule the veld heat af fected zone including the veld rThe stresses respons.sle for cracking a lack of fusion had occurred.
to be primarily residual velding stresses in as much as the calculated applied There is no conclusive stresses were found to be less than code design limits.
this time to identify those aggressive chenical species which evidence at Further analytical efforts in this area and on promoted this ICSCC attar.k.
other system velds is being pursued.
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July 17, 1979 IE Information Notice No. 79-19 Page 2 of 2 Based on the above analysis and visual leaks, the ideensee initiated a broad based ultrasonic examination of potentially af fected systems utilizing The systems examiaed included the spent fuel, decay special techniques.
removal, makeup and purification, and reactor building spray systems oxygenated boric acid environ-heat which contain stagnant or intermittently stagnant, These systems range from 21/2-inch (HPCI) to 24-inch (borated water storage tank suction), are type 304 stainless steel, schedule 160 ments.
to schedule 40 thickness respectively.
Results of these examinctions were reported to the NRC on June 30, 1979 as an update to the May 16, 1979 LER.
10, 1979 has identified 206 velds out The ultrasonic inspection as of July of 946 inspected having UT indications characteristic of cracking randomly the afore=entioned sizes (24"-14"-12"-10"-8"-2" etc.)
distributed throughout of the above cystems.
It is important to note that six of the crack indications were found in 21/2-inch diameter pipe of the high pressure injection lines These lines are attached to the main coolant pipe and inside containment.
are nonisolable from the main coolant system except for check valves.
All of the six cracks were found in two high pressure injection lines containing No cracks were found in the high pressure injection stagnated borated water.
The ultrasonic lines which were occasionally flushed during makeup operations.
examination is con _nuing in order to delineate the extent of the problem.
Enclosures:
1.
List of Information Notices Issued in 1979
IE Information Notice No. 79-19 Page 1 of 2 July 17, 1979 LISTING OF IE INFORHATION NOTICES ISSUED IN 1979 Date Issued To Information Subject Issued Notice No.
79-01 Bergen-Paterson Hydraulic 2/2/79 All power reactor facilities with an Shock and Sway Arrestor OL or a CP 79-02 Att empted Extortion -
2/2/79 All Fuel Facilities Low Enriched Uranium 7 9-03 Limitorque Valve Geared 2/9/79 All power reactor facilities with an Limit Switch Lubricant OL or a CP 7 9- 04 Degradation of 2/16/79 All power reactor facilities with an Engineered CL or a CP Safety Features 79-05 Use of 1= proper Materials 3/21/79 All power reactor facilities with an in Safety-Related Co=ponents OL or CP 79-06 Stress Analysis of 3/23/79 All Holders of Reactor OL or CP Saf ety-Related Piping 7 9-07 Rupture of Radwaste Tanks 3/26/79 All power reactor facilities with an OL or CP 79-08 Interconnection of 3/28/79 All power reactor facilities with an Contaminated Systems with OL and Pu Processing Service Air Syste=s Used fuel facilities As the Source of Breathing Air 79-09 Spill of Radioactively 3/30/79 All power reactor f acilities with an Contaminated Resin OL 79-10 Nonconforming Pipe 4/16/79 All power reactor facilities with a Support Struts CP 79-11 Lower Reactor Vessel Bead 5/7/79 All holders of Reactor OLs and cps
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2 IE Information Notice No. 79-19 July 17, 1979 Page 2 of 2 LISTING OF IE INFORMAT10S NOTICES ISSUED IN 1979 Information Subject Date Issued To Notice No.
Issued
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79-12 Atte=pted Damage to New 5/11/79 All Fuel Facilities Fuel Assemblies Research Reactors, and Power Reactors with an OL or CP 79-13 Indicction of Low Water 5/29/79 All Holders of Reactor Level in the Oyster Creek OLs and cps Reactor 79-14 NRC Position of Electrical 6/11/79 All Power Reactor Cable Support Systems Facilities with a CP 79-15 Deficient Procedur-s 6/7/79 All Holders of Reactor OLs and cps 79-16 Nuclear Incident at Three 6/22/79 All Research Reactors Mile Island and Test Reactors with OLs 79-17 Source Holder Assembly Damage 6/20/79 All Jolders of Reactor Damage From Misfit Between OLs and cps Asse=bly and Reactor Upper Grid Plate 79-18 Skylab Reentry 7/5/79 All Holders of Reactor OLs t'
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