ML19210E443
| ML19210E443 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 11/16/1979 |
| From: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| To: | Daltroff S PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC |
| References | |
| NUDOCS 7912050049 | |
| Download: ML19210E443 (1) | |
Text
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o UNITED STATES 8 y)..- (f',g NUCLEAR REGULATORY COMMISSION 3,? \\
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6 US Docket Nos. 50-277 50-278 Philadelphia Electric Company ATTN:
Mr. S. L. Daltroff Vice President Electric Production 2301 Market Street Philadelphia, Pennsylvania 19101 Gentlemen:
The enclosed IE Circular No. 70-22, " Stroke Times for Power Operated Relief Valves," is forwarder *. 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, W
n G Boyce H. Grier
" Director
Enclosures:
1.
IE Circular No. 79-22 2.
List of Recently Issued Circulars CONTACT:
D. L. Caphton (215-337-5263) cc w/encls:
W. T. Ullrich, Station Superintendent Troy B. Conner, Jr., Esquire Eugene J. Bradley, Esquire Raymond L. Hovis, Esquire Michael J. Scibinico, II, As5istant Attorney General 1500 276 n ot,"o+9
h ENCLOSURE 1 SSINS:
6830 Accession No.:
7908220142 UNITED STATES NUCLEAR REGULATORY COMMISSION h
Tf OFFICE OF INSPECTION AND ENFORCEMENT WASHINGTON, D. C.
20555 U @u,J U --
IE Circular No. 79-22 Date:
November 16, 1979 Page 1 of 1 STR0KE 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 pressure 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 oerformance 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 conduct a review to determine if periodic serveillance of PORVs is necessam 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.
1500 277
A ENCLOSURE 2 IE Circular No. 79-22 Date:
November 16, 1979 Page 1 of 1 RECENTLY ISSUED CIRCULARS Circular Subject First Date Issued To No.
of Issue 79-15 Bursting of High Pres-8/8/79 All Materials Priority sure Hose and Malfunc-I, Fuel Cycle and Opera-tion of Relief Valve "0"
ting Power Reactor Ring in Certain Self-Licensees Contained Breathing Apparatus 79-16 Excessive Radiation 8/16/79 All Radiography Exposures to Members Licansees Of The General Public And A Radiographer 79-17 Contact Problem in 8/14/79 A'l Power Reactor SB-12 Switches on Licensees with an OL General Electric or CP Metalclad Circuit Breakers 79-18 Proper Installation of 9/10/79 All Power Reactor Target Rock Safety-Licensees with an OL F.elief Valves or CP 79-19 Loose Locking Devices 9/13/79 All Power Reactor Licensees on Ingersoll-Rand Pumps with an OL or CP 79-20 Failure of GTE Sylvania 9/24/79 All Power Reactor Licensees Relay, Type PM Bulletin with an OL or CP 7305, Catalog SU12-11-AC with a 120V AC Coil 79-21 Prevention of Unplanned 10/19/79 All Power Reactor Licensees Releases of Radioactivity with an OL or CP 1500 278