ML19210D986
| ML19210D986 | |
| Person / Time | |
|---|---|
| Site: | Perkins, Cherokee  |
| Issue date: | 11/16/1979 |
| From: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | Dail L DUKE POWER CO. |
| References | |
| NUDOCS 7911290135 | |
| Download: ML19210D986 (2) | |
Text
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'o UNITED STATES 8
,I,,o NUCLEAR REGULATORY COMMISSION
)^e, <E REGION 11 g
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101 MARIETTA ST., N.W., SulTE 3100 ATLANTA, GEORGIA 30303 g ****"
s NOV 161979 In Reply Refer To:
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-493_ >50-488 50-489, 50-490 Duke Power Company Attn:
L. C. Dail, Vice President Design Engineering P. O. Box 33189 Charlotte, North Carolina 28242 Gentlemen:
The enclosed IE Circular No. 79-22, is forwarded to you for information.
No written response is required.
Should you have any questions related to your understanding of this matter, please contact this office.
Sincerely,
%a I M-mes P. O'Reilly D ector
Enclosures:
1.
IE Circular No. 79-22 2.
List of IE Circulars Issued In Last Six Months 1434 237 7011290 13 5
Duke Power Company,
cc w/ encl:
J. T. Moore, Project Manager Post Office Box 422 Gaffney, South Carolina 29340 1434 238
i SSINS:
6830 Accession No.:
7908220142 D
NUCLEAR REGULATORY COMMISSION
'*Dt[hin,,1 UNITED STATES OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 November 16, 1979 IE Circular No. 79-22 STROKE TIMES FOR POWER OPERATED RELIEF VALVES Description of Circumstances:
Most PWRs utilize power-operated relief valves (PORVs) to prevent overpressuriza-tion of the reactor coolant system when the reactor is at low temperature.
On April 13, during a pressure transient at Robinson 2, the PORVs did not function as rapidly as intended.
The estimated stroke time for the PORVs was three to five seconds whereas the intended stroke time is tuo seconds.
As a result, the pres-sure transient did approach a pressure limit which is based on nil ductility considerations.
Prior to April 13, the PORVs had not been used or exercised since February, 1978, when they had been repacked and stroked.
Although the valve stems were scored at that time, stroke times were satisfactory.
The licensee and the valve manufacturer believe that the scored stems and the 14-month interval without exercise resulted in poor performance of the PORVs.
Recommended Actions for Licensees' Consideration:
All holders of PWR operating licenses or construction permits should be aware of the potential problem of the type discussed above.
Because of the generic implications in this matter, it is recommended that both licensees of operating facilities and holders of construction permits caduct a review to determine if periodic surveillance of PORVs is necessary to assure that the PORVs will perform as intended.
No written response to this Circular is required.
If you require additional information regarding these matters, contact the Director of the appropriate NRC Regional Office.
1434 239
IE Circular No. 79-22 Enclosure November 16, 1979 Page 1 of 2 LISTING OF IE CIRCULARS ISSUED IN LAST SIX MONTHS Circular Subject Date of Issued to No.
Issued 79-22 Stroke Times for Power 11/16/79 All Power Reactor Operated Relief Valves Operating facilities and all facilities having a CP 79-21 Prevention of Unplanned 10/19/79 All Power Reactor Releases of Radioactivity Operating facilities and all facilities having a CP 79-20 Failure of GTE Sylvania 9/24/79 All Power Reactor Relay, Type PM Bulletin 7305, Operating facilities Catalog SU12-11-AC With A and all utilities 120V AC Coil having a CP 79-19 Loose Locking Devices 9/13/79 All Power Reactor on Ingersoll-Rand Pumps Operating facilities and all utilities having a CP 79-18 Proper Installation of 9/10/79 All Power Reactor Target Rock Safety-Relief Licensees with a CP Valves and/or OL 79-17 Contact Problem in SB-12 8/14/79 All Power Reactor Switches on General Electric Licensees with a CP Company Metalclad Circuit and/or OL Breakers 79-16 Excessive Radiation Exposures 8/16/79 All Radiography To Members Of The General Public Licensees And A Radiographer 79-15 Bursting of High Pressure Hose 8/22/79 All ResearcL Reactors (Correc-and Malfunction of Relief tion)
Valve "0" Ring in Certain Self-Contained Breathing Apparatus 79-15 Bursting of High Pressure Hose 8/8/79 All Ma e i I P i ty I, and Malfunction of Relief Fuel Cycle and Operating Valve "0" Ring in Certain Self-Power Reactor Licensees Contained Breathing Apparatus
S IE Circular No. 79-22 Enclosure November 16, 1979 Page 2 of 2 LISTING OF IE C121CULARS ISSUED IN LAST SIX M01TTHS Circular Subject Date of Issued to No.
Issue 79-14 Unauthorized Procurement and 7/13/79 All Medical Licensees Distribution of XE-133 except Teletheraphy Medical Licensees and to all Radiopharmaceu-tical Suppliers 79-13 Replacement of Diesel 7/13/79 All Power Reactor Fire Pump Starting Operating Facilities Contactors and all Utilities having a CP 79-12 Potential Disel Generator 6/28/79 All Power Reactors Turbocharger Problem Operating Facilities and all Utilities having a CP 79-11 Design / Construction 6/27/79 All Applicants Interface Problem foi, and Holders of Power Reactor cps 79-10 Pipefittings Manufactured 6/26/79 All Power Reactor from Unacceptable Material Licensees with a CP and/or OL 79-09 Occurrences of Split or 6/22/79 All Materials Punctured Regulator Diaphragms Priority I, Fuel In Certain Self Contained Cycle and Operating Breathing Apparatus Reactor Licensees 79-08 Attempted Extortion - Low 5/18/79 All Fuel Facilities Enriched Uranium Licensed by NRC 79-07 Unexpected Speed Increase 5/2/79 All He'ders of of Reactor Reci.rculation BWR OL's or CP's MG Set Resulted in Reactor Power Increase 1434 z41 n
79-06 Failure to Use Syringe 4/19/79 All Holders of and Bottle Shields in Medical Licensees Nuclear Medicine except teletherapy licensees