ML20084Q798

Ao:On 730913,release Rate from Reactor Bldg Vent Stack Was 290 % of Limit for I-131 & Particulates W/Half Lives Longer than 8 Days.Cause May Be Attributed to Existing Minor Leaks in Combination W/Increase in Iodine in Coolant

ML20084Q798
Person / Time
Site:	Quad Cities
Issue date:	09/21/1973
From:	Stephenson B COMMONWEALTH EDISON CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20084Q697	List: ML20084Q724 ML20084Q756 ML20084Q766 ML20084Q770 ML20084Q775 ML20084Q778 ML20084Q784 ML20084Q787 ML20084Q791 ML20084Q794 ML20084Q798 ML20084Q800 ML20084Q809 ML20084Q816
References
BBS-73-192, NUDOCS 8306140166
Download: ML20084Q798 (3)

Text

---. . .- - .

.- wa h '-* O Commalth Edison A

V

.* lQ Quid-Cities Generating Station Post Office Box 216 Cordova, Illinois 61242 Telephone 309/654-2241 O b a'

,, A BBS-73-192 g% i j 4

Q %bj  :.

(jk 9 September 21, 1973 \ b g

AI e John F. O' Leary, Director

' Directorate of Licensing Regulation U. S. Atomic Energy Commission Washington, D.C. 20545

Subject:

Quad-Cities Nuclear Power Station Docket Nos. 50-254 & 50-265 DPR-29 & 30, Appendix A Sections 1.0.A.2, 3.8.B.3.a & 6.6.B

Dear Mr. O' Leary:

On September 14, 1973 it was determined that the release rate from the reactor building ventilation stack on September 13th had been 290% of the limit for iodine-l.l and particulates with half lives longer than 8 days specified by section 3.8.B.3.a of the Technical Specifications. This abnormal occurrence was previously repot-ed by telegram on September 14, 1973.

Unlike previous occurrences of this nature the release on the 13th could not be attributed to any specific leaks or contain-ment venting. In discussing the occurrence with inspectors

, from the Region III office of the Directorate of Regulatory Operations it was suggested by them that the airborne activity may have been increased due to existing minor leaks alone in combination with an increase in iodine in the coolant. This

/

seems very plausible since the coolant iodine activity had increased by a factor of about ten following a scram on Unit 1 at 1704 on September 12, 1973.

The 290% of limit reported for September 13th was based on analysis of the I-131 sample cartridge alone which was counted shortly after removal on the morning of the 14th and represented a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> sample. A similar sample removed about 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> after the scram on the 12th showed the release for the day of the scram to be 35% of the LCO. The 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> count of the particulate sample for that day, however, indicated that the

/

kho O 54 g l }. coPV SENT REGION -

S PDR 3

C' . ,' /3

,J  %)

Mr. J. O' Leary September 21, 1973 combination of I-131 and long lived particulates were 111%

of the LCO. The 48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> count of the September 13th part-iculate sample revealed a release rate equivalent to 1425%

of the limit. These release rates can best be summarized by the following table, keeping in mind that the first in-formation on iodine and particulates is not available until 3 days after the release date making isolation of the vent system a futile action. This table includes all results available as of September 21, 1973.

48 hour5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> Final (7 day)

Date of  % of LCO  % of LCO  % of LCO Release I-131 only I-131 & Part. I-131 & Part.

9/ll-typical 15 24 23 9/12-scram 35 111 104 9/13 290 1425 1277 9/14 62 136 9/15 76 136 9/16-scram 56 80 9/17 70 1;2 9/18 54 76

• 9/19 36 9/20 33 9/21 After exceeding the limit on the 13th the SGTS was started and the vent system isolated. The vent system was started again on the 14th with several samples being pulled and

1. analyzed immediately throughout the day to verify that the I-131 concentration was within limits. As shown above the average release for that date was 62% of the LCO based on the iodine cartridges, but again 3 days later the particulate and iodine release was found to have been 136% of the limit for that date.

At 1925 on September 16, 1973 a scram occurred on Unit 2 and  ;

subsequently resulted in another abnormal ~ occurrence on the  !

17th. The release rates are given in the table above. This was reported by telegram on September 21, 1973. j I

k

I e .: :. Q Q l

. l Mr. J. O' Leary September 21, 1973 Our evaluation and review of these occurrences has not yet been completed. The purpose of this letter is to inform you of our current situation and fulfill the 10 day reporting requirement of paragraph 6.6.B.l.a of the Technical Speci-fications for the abnormal occurrences reported on Septem-ber 14 and 21, 1973. An additional report will be submitted in the near future which will include the final analysis -

of all samples and the results of our review.

Very tr,uly yours, COMMONWEALTH EDISON COMPANY QUAD CITIES NUCLEAR POWER STATION

/~ B. B. Stephenson Station Superintendent M

BBS/lk

cc: Regional Director Directorate of Regulatory Operations - Region III O

t i

I