ML19254F274
| ML19254F274 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 11/01/1979 |
| From: | Herbein J METROPOLITAN EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| GQL-1336, TAC-63083, NUDOCS 7911070460 | |
| Download: ML19254F274 (2) | |
Text
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c Metropolitan Edison Company e
Post Office Box 542 Reading Pennsylvania 19640 215 929-3601 Writer's Direct Dial Number November 1, 1979 G2L 1336 Director of Nuclear Reactor Regulation R. W. Beid, Chief Operating Reactors Branch No. 4 U. S. Nuclear Regulatory Camlissicn Washington, D. C.
20555
Dear Sir:
Three Mile Island Nuclear Station, Unit 1 Operating License No. DPR-50 Docket No. 50-289 Reactor Vessel Internal Vent Valves The prolonged Uhit 1 outage will requLra that surveillances dt -
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" refueling period' basis be reperformed before the Cycle 6 re: eling.
The Tech. Spec. definition (T.S.1.2.8) of a " Refueling Interval" limits the interval to no nore than 24 nanths without NIC approval, and it appears unlikely that the Cycle 6 Refueling will occur by February 1981.
Technical Specification 4.16.1 concerning R. V. Internal Vent Valves is of particular importance T.S. 4.16.1 requires that the Vent Valves be exercised and visually inspected cnce each " refueling period", ard therefore falls into the category of surveillances which may have to be repeated.
After considering the options Met-Ed requests that the NIC grant an extension on the surveillance interval. Renoval of R. V. Head does i alude scue risk, and there are persannel safety cancerns with any rajor lift and tha personnel radiation exposures to perform these evolutions are significant. Frcm the standpoint of public health and safety there is an increased prnhnhPity of damage to irradiated fuel whenever the R.V. Head is not in place and while it is being moved.
Since June 1974 when initial criticality was achieved the eight internal vent valves have each been tested four times over the last five years for a total of 32 functional tests wit.hout a single failure.
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- v\\v MetropoLtan Ecson Comoany is a Member of tre General Pubhc Ut:!;t:es System 79ll 7
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flovember 1,1979 R.W. REID G2L 1336 Due to concerns about vent valves wear at other B&W Units one vent valve was renoved and given a detailed ermunation during the Cycle 5 refueling.
No noticeable wear was found which verifies the excellent performance of the vent valves in Unit 1.
'Ihe present mode of operation, which will continue until Cycle 5 Startup, places the valves in a favorable environment. 'Ihe low PC flow rates, tight chemistry controls, and absence of power operation will cause little, if any w ar or crud deposition. 'Ihe valves will not be subjected to the major cause of wear, high 10 flow, for a longer than usual period since this depends an the Cycle length (Cycle 5 is 265 + 15 EFPD) which has not changed. The effect of the prolonged shutdown period combined with a normal cycle length should rtainly not be significantly greater than that resulting frtm the first cycle of operation which was 467.4 EFPD of operation over scme 20 calendar months.
In conclusian, Met-Ed requests an extension an the surveillan interval for T.S. 4.16.1.
Sincerely, 7..,/
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' J. G. Herbeln Vice President Nuclear-Operations JGI:DGM:mzm
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