ML20127M162
| ML20127M162 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/08/1985 |
| From: | Hukill H GENERAL PUBLIC UTILITIES CORP. |
| To: | Murley T NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| 5211-85-2070, NUDOCS 8507010125 | |
| Download: ML20127M162 (2) | |
Text
.;..n GPU Nuclear Corporation Nuclear
=,orst;48o Middletown, Pennsylvania 17057-o191 717 944 7S21 TELEX 84 2386 Writer's Direct Dial Number:
June 8, 1985 5211-85-2070 Dr. Thomas E. Murley Region I, Regional Administrator U.S. Nuclear Regulatory Commission 631 Park Avenue King of Prussia, Pa.
19406
Dear Dr. Murley:
Three Mile Island Nuclear Station Unit 1 (TMI-1)
Operating License No. DPR-50 Docket No. 50-289 Primary to Secondary Leak Rate Monitoring Amendment 103 to the TMI-1 Operating License imposes a license condition as follows:
".. 2 GPU Nuclear Corporation shall confirm the baseline primary to secondary leakage rate established during the steam generator hot test program.
If leakage exceeds the baseline leakage rate by more than 0.1 gpm the facility shall be shutdown and leak tested.
If any increased leakage above baseline is due to defects in the tube free span, the leaking tube (s) shall be removed from service.
The baseline limit shall be re-established, provided that the leakage limit of Technical Specification 3.1.6.3 is not exceeded."
The purpose of this letter is to describe the methods by which GPU Nuclear Corporation will comply with this license condition.
Initial baseline leakrate has been established as 0.5 gph by a krypton leak test during pre-critical hot functional testing (see GPUN letter 5211-85-2099 dated May 28,1985). An increase of more than a nominal 6 gph above this baseline during steady state power operation as determined by the methods described below, requires facility shutdown and leak testing.
If leakage is due to defects in the tube free span, the leaking tubes are to be removed from service.
The baseline would be re-established following shutdown and leak testing, either by bringing the plant to power and making a primary to secondary leakrate determia.. lon after equilibrium conditions have been attained (if repairs have been maae to reduce leakage), or by utilizing the mean leakrate value prior to shutdown (if no repairs have been made).
8507010125 85060s DR ADOCK 05000289 p
PDR GPU Nuclear Corporation is a suosiurary of the General Public Utilities Corporation
/O p
. M' o.
5f11-85-2070. June 8, 1985 Primary to secondary leak rate will be determined at power once the RCS Xenon activity is sufficient to allow leakage detection.
The leakrate determination w'lll be based on evaluation of three parameters which may vary during steady state power operation:
reactor coolant system measured activity, condenser off-gas measured activity, and condenser off-gas flow rate. Primary system samples are taken and analyzed routinely per Technical Specification Table 4.1-3, Item 1, as a minimum. The monitored off-gas activity provides the first indication of suspected elevated primary to secondary system leakage.
A leakrate calculatico is performed once per shift, per plant procedure, based upon off-gas activity indicated by the off-gas monitor, the most recent primary sample activity, and the off-gas flow rate.
In addition, the leakrate based on off-gas grab sample activity will be determined on a daily basis, as a minimum, and these values will be plotted for trend analysis.
Parameters affecting primary to secondary leakrate measurement may vary due to plant conditions, transients, and normal measurement or analysis error.
Procedural steps have been established to account for these variations to ensure valid leakrate values are calculated and used for decision making while still assuring prcmpt action is taken when necessary. Due to the variability of these parameters and the extremely low leakage limit, a period of time will be required to confirm an actual leakage rate.
For leakrates close to the 6 gph above baseline limit, up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> may be taken to confirm that this limit has been exceeded.
Higher indicated leakrates would allow less time for confirmation.
These methods for calculating the leakrate have advanta methods described in TR-008 (pages 89-90 and Table X-1)ges over some of the Therefore, the methods above will be used in lieu of the procedures described in TR-008.
TMI-1 Procedure 1301-1 " Shift and Daily Checks" includes required activities for ensuring compliance with this license condition.
This procedure is available for audit at the TMI site.
Sincerely, Director, TMI-1 HDH/MRK/spb:0227A cc:
J. F. Stolz J. Thoma R. Conte
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