ML20140E041

Forwards Containment Sys Branch Input for Response to Citizens Against Nuclear Power Petition for Emergency Relief Re Integrated Leak Rate Test.Containment Integrity Confirmed & Verified.Tac 55267 Closed

ML20140E041
Person / Time
Site:	Zion File:ZionSolutions icon.png
Issue date:	12/21/1984
From:	Houston R Office of Nuclear Reactor Regulation
To:	Lainas G Office of Nuclear Reactor Regulation
Shared Package
ML20140C940	List: IA-85-136, Forwards marked-up Draft Containment Sys Branch Response to Items in Affidavit Attached to Citizens Against Nuclear Power 840605 Petition Re Integrated Leak Rate Testing at Facility.Containment Integrity Confirmed.Matter Closed ML20140C933 ML20140C981 ML20140E041 ML20140F491 ML20140F558 ML20140F607 ML20140F916 ML20140F989 ML20140G009 ML20140G034
References
FOIA-85-136 TAC-55267, NUDOCS 8501030280
Download: ML20140E041 (11)

Text

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UNITED STATES E 'j 3, , f g NUCLEAR REGULATORY COMMISSION ,

'Qg Qfg gp# r WASHINGTON, D. C. 20555 December 21, 1984

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! Y MEMdRANDUMFOR: G. C. Lainas, Assistant Director for Operating Reactors, DL FROM: R. W. Houston, Assistant Director for Reactor Safety, DSI

SUBJECT:

INPUT FOR RESPONSE TO PETITION FOR EMERGENCY RELIEF RE: ILRT AT ZION, UNIT 1 (TACS 55267)

Reference:

1. Petition for Emergency Relief to the U.S. Nuclear Regulatory Comission, Re: Commonwealth Edison Company, Zion, Unit 1, dated June 5,1984, Submitted by Citizens Against Nuclear Power

2. Memorandum for D. G. Eisenhut (NRR), from R. L. Spessard (RIII),

dated September 7, 1984 In response to Technical Assistance TACS No. 5526.7, the Containment Systems Branch (CSB) has completed a review of the Petition (Reference 1) and its at-tached affidavit by Dr. Z. V. Reytblatt. In essence, the Petition questioned the validity of the containment integrated leak rate test performed on Zion,

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Unit I during March, 1981. As a result, NRC Region III conducted an independ-ent investigation of the 1981 and 1983 test at Zion, Unit 1. The results of this investigation are documented in Reference 2. The CSB has reviewed the Region III report and concurs in its findings.

The Affidavit attached to the Petition is represented by the Petitioner as the technical support to the allegations contained in the Petition. Therefore, in responding to the Petition, the CSB has responded to the pertinent items (12 through 18) of the Affidavit. These responses are contained in the enclosure.

We concur with the general comment by Reytblatt that the containment leak rate as stated in the test report could not be verified by the 1981 and 1983 test results. As a result, we informed the licensee of our concern, and indicated that a demonstration of containment leak tightness was necessary for continued operation of Zion, Unit 1. On July 18, 1984, Comonwealth Edison Company, shut down Zion, Unit 1, and performed an integrated leak rate test during the CONTACT: J. Huang, CSB x29493 g>3pfffXb :or A l% 0# #

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G. Lainas period from July 27 to August 1, 1984, under close supervision of the NRC inspectors. The ILRT was found successful. Therefore, we conclude containment integrity has been confirmed and verified, and therefof(J,, hatconsider the,subfect matter closed.

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- 'WE R. Wayne Houston, Assistant Director for Reactor Safety Division of Systems Integration

Enclosure:

As stated cc: R. M. Bernero D. G. Eisenhut R. L. Spessard, RIII F. Maura, RIII J. Norris G. Arndt -

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CSB RESPONSES TO ITEMS 12 THROUGH 18 0F THE REYTBLATT AFFIDAVIT ON THE 1981 ZION, UNIT 1 CONTAINMENT INTEGRATED LEAK RATE TEST

12. Event logs of the 1981 Test, a summary of which is contained ) ihe Ceco av -

. Test Report, describe the following events on March 12, 1981:

1. From page 10:

"0300 Completed normal ILRT at data set #326."

"0429 Began induced leakrate test."

"1200 HUT recirc. pump stopped."

4-Reytblatt's Comment:

This quotation means that approximately ninety minutes after the completion of the Basic Test, a Verification Test (the " induced leakrate test") was performed, but it did not yield the expected results. The Verification Test did not validate the satisfactory performance and reliability of the Basic Test.

CSB Response:

A review of the 1981 Zion Test indicates the calculated leak rate from the Basic Test is 0.0158 w/o/ day, which is only a small fraction (20%) of the allowable leak rate for the Zion containment. A small leak rate is 4

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difficult to verify, especially when the imposed leak rate for the verification test is also small. This is what happened during the 1981 P

Test at Zion. From the available test data, the difference bet en the Basic Tot and the first Verification Test was as high as 0.72 L, ri er than within

~ the 0.25 L, limit. It can only be concluded that'it is not possible to quantify the leakage rate for the Zion, Unit 1, containment building from the overall test performance.

ii. From the same page:

"1400 Re-initialized imposed leak calculations from 369."

Reytblatt's Comment:

This quotation shows that eleven hours after the completion of the Basic Test, a second Verification Test was performed, and again failed to prove the validity of the Basic Test.

CSB Response:

After the licensee thought the problem with the "first" Verification Test had been corrected, a new " start" time was selected for a "second" Verification Test. (The start time selected was for data set #369. However, the "second" Verification Test gave a result within 0.34 L,, which again exceeded the required accuracy of 0.25 L,.

. 3 111. From the same page:

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1700 Re-initialized from 367. .[

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T 1745 Terminated imposed leak test at set 405."

Reyblatt's Comment:

This means that fourteen hours after the completion of the Basic Test, a third Verification Test was started. This Verification Test was completed in forty-five minutes, and was deemed to be a proof of validity of the Basic Test.

CSB Response:

Although it is the licensee's view that two verification tests were performed, the NRC considers it to have been one continuous verification test lasting for about twelve hours. However, three calculations were performed using three different sets of data from the same verification test. The third calculation produced a result that fell within the required accuracy of 0.25 L,.

It is acceptable to conduct several verification tests, if valid reasons are given for the unacceptability of previous verification tests. With respect to Zion, in order to obtain the required accuracy of 0.25 L3 , the licensee selected, toward the end of the 12-hour test, the desired data set. From a sti.tistical standpoint, this is not an acceptable practice. Consequently, the 1981 Zion Test result had not been verified.

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4 iv. From page 15 of the CECO Test Report:

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- T Date Level Volume Added inches inches gallons" "3-11-81 20.5 9.5 47.0 3-12-81 21.0" Reytblatt's Comment:

This quotation proves that on March 12, 1981 - during the same time '

period that these Verification Tests were carried out - a procedure known as IW (" Irrigation Water Injection") had been applied to the containment environment. A total of approximately 44 gallons of water was injected, which might have substantially changed the containment environment.

CSB Response:

Our review of the 1981 test indicates that water was found to be leaking from an engineered safeguards penetration seal water system into the containment 4

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. . 5 during the second day of data taking, and that this continued until the end of the Verification Test. Therefore, we disagree that the containment environment was substantially changed during the Verification Test L

ince water fakage had. occurred for seven days prior to the start of thh VerifiAationTest,containmentconditionsshouldhavebeencomparableduring both the Basic Test and the Verification Test.

Reytblatt's Comment:

13. Failure of the first Verification Test proves that the Basic Test had been deficient.

CSB Response:

We acknowledge that the Verification Test result, based on the first data set, did not verify the leak rate of the Basic Test within the required accuracy (20.25 L,). We do not agree that this proves the Basic Test was deficient but rather that the Basic Test was not verified. Furthermore, failure to determine the cause of the verification test failure, to correct the problem, and to perform a successful verification test does invalidate any conclusion that may have been drawn regarding the success of the overall test.

Reytblatt's Comment:

14 Failure of the second Verification Test provides further confirming evidence that the Basic Test had been deficient.

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. 6 CSB Response:

Again, the licensee did not perform a second verification test; ratt d r, a

secondfilculation was done using a different data set from the saEC verifica- _

tion test. This calculation also did not verify the Basic Test result. Taken alone, it does not confirm that the containment integrity is unacceptable, only that the overall test was deficient.

Reytblatt's Comment:

15. The Verification Test shou'9,3 be conducted imediately upon conclusion of the Basic Test, so that there will be little risk of changes occurring in the containment environment. However, during the 1981 Test, in fourteen 4

hours since the completion of the Basic Test, two Verification Tests failed, and also, due to the IW application, significant alteration in the containment environment may have occurred. The third Verification

• Test therefore cannot be considered valid. .

CSB Response:

The IW application actually started very early in the test, and was not an event that suddenly occurred during the Verification Test. Therefore, it is

, not a question of whether the Verification Test should be considered valid, or the Basic Test deficient, but rather a question of whether the Verification Test had' verified the capability of the instrumentation to measure the small

eakage rates that Zion was reporting.

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. . 7 Reytblatt's Comment:

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16. By not analyzing the reasons why the Verification Tests faile and by

. repeating the Basic Test, which was certainly necessary under these circumstances, the testing organization violated the Standard.

CSB Response:

Appendix J to 10 CFR 50 requires that if the supplemental test result is not within 0.25 L,, the reason shall be determined, corrective action taken, and a successful supplemental test perfomed. Our review of the 1981 test indicates that the licensee did not establish a valid reason-for the inability to verify the Basic Test result after using two data sets from the supplemental test

.. (Verification Test), and failed to perform a subsequent, successful supplemen-tal test.- Instead, the licensee inappropriately made a post-test selection of data from the same Verification Test to establish the required accuracy of the Basic Test result. This "look-back" selection of data:is unacceptable to the NRC staff. Therefore, we conclude that the 1981 Zion Test did not comply with the requirements of Appendix J in that a successful supplemental test had not been performed.

I Reytblatt's Comment:

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. 17. In my opinion, it is inconceivable that the testing organization had no l knowledge of the unacceptability of repeated Verification Tests. More-i

{ over, out'of three Verification Test results, two of which showed the i

Basic Test to be deficient, the testing organization selected the third

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. 8 Verification Test results, although these results were obtained after the containment environment may have significantly changed. In m opinion, such actions can only be described as fraud. -

CSB Response Our review of the 1981 test indicates that the testing organization misused the

c. C Verification Test data; we can find no evidence of fraudul, ant conduct. k Reytblatt's Coment:

18. In summary, the 1981 test is invalid and provides no assurance whatever that the Zion, Unit I reactor containment leak rate is as stated in the Test Report.

CSB Response:

We agree, in principle, with the sumary statement. As a result, the NRC Region III conducted an independent review of both of the 1981 and 1983 Zion ILRT results and concluded that the Zion, Unit 1, reactor containment leak rates as stated in the test reports could not be verified. Consequently, the NRC Region III informed the licensee of their findings and indicated that a demonstration of containment integrity was necessary for continued operation of Zion, Unit 1. The licensee shut down the Zion plant in July 1984, and a satisfactory Type A test was performed. NRC inpsectors were present as

9 observers throughout the course of the test. (A detailed review of the Zion, Unit 1 Type A tests performed in 1981, 1983, and.1984 is presented. the staff report from R. L. Spessard, Division of Reactor Safety, Region III, o D. G.

Eisen . Division of Licensing, NRR, dated September 7, 1984.)

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