ML20084E214
| ML20084E214 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 05/21/1974 |
| From: | Amish K ROCHESTER GAS & ELECTRIC CORP. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| Shared Package | |
| ML20084E218 | List: |
| References | |
| AO-50-244-74-08, AO-50-244-74-8, NUDOCS 8304140441 | |
| Download: ML20084E214 (3) | |
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j na ROCHESTER GAS AND ELECTRIC CORPORATION e 89 EAST AVENUE, ROCHESTER, N.Y.14549 a t iv.- w a v e s.*
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@ ggy 281974 (1 Mr. James P. O'Reilly, Director Directorate of Regulatory Operations a
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Subject:
Abnormal Occurrence 74-8:
An unplanned release of radioactive material from the site boundary R. E. Ginna Nuclear Power Plant, Unit No.1 Docket No. 50-244
Dear Mr. O'Reilly:
in ecccrdence '"ith achni-al 4acificatiena, Mima A. A. N. th a attached report of Abnormal Occurrence 74-8 is hereby submitted.
Very ly yours, 7te Keith W. Amish Attachment xc: Mr. John F. O' Leary./
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Report Number:
50-244/74-8 2a.
Report Date:
May 21,1974 2b.
Occurrence Date:
May 11,1974 3.
Facility:
R. E. Ginna Nuclear Power Plant, Unit No.1 4.
Identification of Occurrence:
This abnormal occurrence is defined by Technical Specification-
- 1. 9c:
An unplanned release of radioactive material from the site boundary.
5.
Conditions Prior to Occurrence:
The Plant was operating at a steady-state power level of 70%.
There was 40 gpm primary coolant letdown through the "A" mixed bed demineralizer. The auxiliary building air cleaning and exhaust system was operating properly.
6.-
Description of Occurrence:
During the 0000-0800 shift on May 11, 1974, an increase in the gas radiation level of the auxiliary building exhaust at the plant vent was noticed. Immediate investigation de:crmined that there was some leakage of water into the NaOH tank rocm from the domineralizer vault s u u m w iilcit i= 'un Lite ne4L fivu above. T;te inixed bed decninecalizers were bypassed to determine if the leakage was from one of the domineralizers.
This operation appeared to reduce the leakage. The mixed bed domineralizers were then put back in service and alternated and it was determined that the leakage occurred when the "A" mixed bed domineralizer was in service.
The "B" mixed bed demineralizer was placed in service and the "A" mixed bed domineralizer was isolated.
7.
Desianation of Annarent Cause of Occurrence:
Primary coolant leaked from the letdown system in the domineralizer vault room. Associated dissolved radiogases were released to the room atmosphere and were drawn into the auxiliary building ventilation system.
A visual inspection made through a leaded glass window at the room entry revealed dripping in the general location of the "A" mixed bed l
domineralizer outlet piping. Due to the~ location of the leak, a detailed i
inspection cannot be made at this time.
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8.
Analysis of Occurrence:
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The release did not cause any hazard to plant personnel or the public off-site. Ventilation from this room goes directly to the auxiliary -
building exhaust system. Charcoal filters and HEPA filters remove iodine and particulate activity before the air is released through the plant vent to the atmosphere. The plant vent is continuously monitored for radioactive gases, particulate and iodine.
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Abnormal Occurrence 50-244/74-8 cont'd.
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There was no increase in iodine or particulate measured by the plant vent monitors. The maximum release rate for the radioactive gases occurred between 1300 and 1400 hours0.0162 days <br />0.389 hours <br />0.00231 weeks <br />5.327e-4 months <br /> on May 11, 1974. This release rate was 1.6% of the Technical Specification limit and occurred just prior to the isolation of the "A" mixed bed demineralizer.
The average release rate between 0000 and 1200 hours0.0139 days <br />0.333 hours <br />0.00198 weeks <br />4.566e-4 months <br /> on May 11,1974 was 0.66% of the Technical Specification limit and this amounted to 8.64 Ci.
The average release rate between 1200 and 2400 hours0.0278 days <br />0.667 hours <br />0.00397 weeks <br />9.132e-4 months <br /> on May 11,1974 was 0.33% of the Technical Specification limit and this amounted to 4.32 C1.
By 1600 hours0.0185 days <br />0.444 hours <br />0.00265 weeks <br />6.088e-4 months <br /> on May 11, 1974, which was two hours after isolating the leak, the release rate to the atmosphere had returned to its previous level of approximately 0.1% of the Technical Specification limit.
9.
Corrective Action:
The immediate action was to find and isolate the leak. The permanent corrective action will be determined when access to the demineralizer vault can be arranged.
10.
Failure Data:
A simuar leak occurrea in Decemoer,1r/2. Tne leak was.
isolated and ropairs were made on April 4,1974.
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