ML19256F364
| ML19256F364 | |
| Person / Time | |
|---|---|
| Site: | Dresden  |
| Issue date: | 11/19/1979 |
| From: | Pappas H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III) |
| References | |
| NUDOCS 7912190013 | |
| Download: ML19256F364 (3) | |
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E MEMORANDUM FOR: Those on Attached List FROM:
Helen Pappas, Chief, Administrative Branch
SUBJECT:
IE CIRCULAR NO. 79-22 The attached IE Circular No. 79-22 titled " Stroke Times For Power Operated Relief Valves" was sent to the following licensees on November 16, 1979, for information:
American Electric Power Service Corporation Indiana and Michigan Power Company D. C. Cook 1, 2 (50-315, 50-316)
Cincinnati Gas & Electric Company Zimmer (50-358)
Cleveland Electric Illuminating Company Perry 1, 2 (50-440, 50-441)
Commonwealth Edison Company Braidwood 1, 2 (50-456, 50-457)
Byron 1, 2 (50-454, 50-455)
Dresden 1, 2, 3 (50-10, 50-237, 50-249)
La Salle 1, 2 (50-373, 50-374)
Quad-Cities 1, 2 (50-254, 50-265)
Zion 1, 2 (50-295, 50-304)
Consumers Power Company Big Rock Point (50-155)
Midland 1, 2 (50-329, 50-330)
Palisades (50-255)
Dairyland Power Cooperative LACBWR (50-409)
Detroit Edison Company Fermi 2 (50-341)
Illinois Power Company Clinton 1, 2 (50-461, 50-462) 1625 028 7 91219 oo /.3
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Addressees - Memorandum dated November 19, 1979 IE Files MPA/DTS Central Files Reproduction Unit hTC 20b 1625 029
Those on Attached List NL'i J,
Iowa Electric Light & Power Company Duane Arnold (50-331)
Northern Indiana Public Service Company
'Bailly (50-367)
Northern States Power Company Monticello (50-263)
Prairie Island 1, 2 (50-282, 50-306)
Ohio Edison Company Erie 1, 2 (50-580, 50-581)
Public Service of Indiana Marble Hill 1, 2 (50-546, 50-547)
Toledo Edison Company Davis-Besse 1 (50-346)
Union Electric Company Callaway 1, 2 (50-483, 50-486)
Wisconsin Electric Power Company Point Beach 1, 2 (50-266, 50-301)
Wisconsin Public Service Corporation Kewaunee (50-305)
Helen Pappas, Chief Administrative Branch
Attachment:
IE Circular No. 79-22 RIJI
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1625 030 11/16/79
SSINS:
6830 Accession No.
7908220142 UNITED STATES NUCLEAR REGULATORY COMMISSION 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 two 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 'iscussed above.
Because of the generic implications in this matter, it is recommended that both licensees of operating facilities and holders of construction permits conduct a review to determine if periodic serveillance of PORVs is necessary to assure that the PORVs will perform as intended.
No v-itten responer to this Circular is required.
If you require additional information regarding these matters, contact the Director of the appropriate NRC Regional Office.
Enclosure:
Recently Issued IE Circulars 1625 031
IE Circular No. 79-22 Enclosure November 16, 1979 RECENTLY ISSUED IE CIRCULARS Circu'ar Subject Date of Issued to No.
Issue 79-21 Prevention of Unplanned 10/19/79 All holders of Power Releases of Radioactivity Reactor OLs and cps 79-20 Failure Of GTE Sylvania Relay 9/24/79 All utilities having a Type PM Bulletin 7305, Catalog CP SU12-11-AC With A 120V AC Coil 79-19 Loose Locking Devices on 9/13/79 All Power Reactor Ingersoll-Rand Pumps Operating facilities and all utilities having a CP 79-18 Proper Installation of 9/10/79 All Holders of a Target Roc l Safety-Relief Power Reactor OL Valves or CP 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 8/8/79 All Materials Priority I, and Malfunction of Relief Fuel Cycle and Operating Valve "0" Ring in Certain Self-Power Reactor Licensees Contained Breathing Apparatus 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 16:25 032