ML20087J703
| ML20087J703 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 03/20/1984 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Stolz J Office of Nuclear Reactor Regulation |
| References | |
| RTR-NUREG-0737, RTR-NUREG-737, TASK-2.D.1, TASK-TM 5211-84-2073, NUDOCS 8403230040 | |
| Download: ML20087J703 (1) | |
Text
_____ __________ -_____-_-_
GPU Nuclear Corporation Nuclear
- , oms::,v8o r
Middletown, Pennsylvania 17057-0191 717 944 7621 TELEX 84 2386 Writer's Direct Dial Numbec March 20, 1984 5211-84-2073 Of fice of Nuclear Reactor Regulation Attn. J. F. Stolz, Chief Operating Reactors Branch #4 Division of I' :ensing U. S. Nucleat Regulatory Commission Washington, D.C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit I, (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Relief and Safety Valve Testing (NUREG 0737, II.D.1)
In response to your letter of February 15, 1984 GPUN has had previous plans to install a heavier spring to make 'the PORV more leak tight at lower pressures by June 1984.
The heavier spring has been endorsed by the manufacturer and should prevent weeping and wirecutting.
(Note that wirecutting is not related to activation setpoint which is electromatic ir. nature).
The PORV with the heavier spring was actuated at Wyle Labs at 485 and 2450 psig and leak rate tested at 150 and 2300 psig. The new spring assists the pilot disc in seating at low pressures. The spring has no effect at high pressure because the spring force is only a small fraction of the total forces acting on the disc. There-fore, TMI-1 is adequatedly represented by the EPRI valve tests.
Recent discussions with the valve manufacturer indicate that the 1000 psig precaution made in 1976 were overly conservative (which contrasts with the PORV manual precaution at 500 psig). With the installation of the heavier spring no precautions for block valve isolation will ordinarily be recuired.
Sincerely,
- kill, Director, TMI-1 IIDil:CWS:mle cc:
R. Conte J. Van Vliet 8403230040 840320 DR ADOCK 05000289 i
PDR Iff GPU Nuclear Corporation is a subsidiary of the General Public Utilities Corporation