ML19256C957
| ML19256C957 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 06/22/1979 |
| From: | Liza Cunningham NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-79-184, NUDOCS 7910150786 | |
| Download: ML19256C957 (2) | |
Text
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N PRELIMINARY NOTIFICATION June 22, 1979 PRELI2!INARY NOTIFICATION OF EVENi 3R UNUSUAL OCCURRENCE--PNO-79-184 This preliminary notification constitutes EARLY notice of event of POSSIBLE safety or public interest significance.
The information presented is as initially received without verification or evaluation and is basically all that is known by IE staff on this date.
Facility:
Philadelphia Electric Company Peach Bottom Unit 3 (DN 50-278)
Subject:
EXCEEDED INSTANTANE0US RELEASE RATE DURING STARTUP FOLLOWING UNSCHEDULED SHUTDOWN OF JUNE 21, 1979.
During a startup of Unit 3 at about 5:00 p.m. on June 21, 1979 (Reference PNO-79-180 for details concerning the shutdown) the instantaneous release rate was exceeatJ, as indicated by the strsk monitors which peaked at 106% of the limit. The maximum duration of the release was reported to be 50 minutes and is apparently related to earlier re ctor depressurization action.
This level coupled with Unit 2 and Unit 3 Vent Stack contributions resulted in a short te rm relea.2 of approximately 116% of the instantaneous limit.
During the night while working with the vacuum pump, vacuum breakers and valving, other minor spikes were noted which did not exceed limits or expected values.
As control rods were inserted to maintain pressure, increases on the Main Steam Line Radiation Monitors were noted.
At 5:00 A.M., June 22, 1979, when condenser vacuum breakers were opened fully, stack monitor indications showed an additional spike of similiar magnitude (about 106 % of the Technical Specification limit) The monitor level has now decayed to background.
The energy levels contributing to this release are expected to result in a real release valve of about 50 percent of instantaneous Technical Specification Limits.
The licensee is removing stack and vent monitor filters for counting. The reactor remains critical with the MSIVS open, and the bypass valvec closed.
Stack monitor indications are normal and the licensee is continuing with this startup in a cautious and deliberate manner without benefit of the mechanical vacuum pump.
Prior to this event, the releases for the current calendar quarter had approached 12.2 percent of the quarterly release limit.
Based on current information, it is not expected that the quarterly release limits will be exceeded.
Media interest is expected because of sensitivity to nuclear plant issues. The
. Commonwealth of Pennsylvania has been informed of both radiation levels at the stack monitor.
A press release was issued by the licensee. Region I is responding to news media inquiries.
CONTINUED 1447 353 7030 v.
y s
Continued June 22, 1979 Page 2 PNO-79-184 NRC, Region I (Philadelphia) received notification of this occurrence by telephone from the plant superintendent at 8:01 p.m., June 21, 1979.
An IE health physicist has been dispatched to the site to review the occurrence.
Contact:
LJCunningham, IE x28188 GKlingler, IE x28019 Distribution:
Transmitted H St /2 '30 Chairman Hendrie Commissioner Bradford S. J. Chilk, SECY Commissioner Kennedy Commissioner Ahearne C. C. Kammerer, CA Commissioner Gilinsky ACRS (For Distribution)
Transmitted: MNBB /):6 P. Bldg /J.'4/3' V. Stello IE H. L. Ornstein, EDO H. R. Denton, NRR Region d /.*/
L. V. Gossick, EDO' R. C. DeYoung, NRR J. J. Fouchard, PA R. J. Mattson, NRR N. M. Haller, MPA R. S. Boyd, NRR (MAIL)
R. G. Ryan, OSP SS Bldg /J.* f[
J. J. Cummings, OIA H. K. Shapar, ELD W. J. Dircks, NMSS R. Minogue, SD
- s. Levine, RES PRELIMINARY NOTIFICATION
[447 554