ML20214F346

Responds to NRC Re Violations Noted in IE Insp Rept 50-455/86-24.Corrective Actions:Test Procedure 2.93.62 Carefully Reviewed & Parametric Study Performed.Violation Should Be Reclassified

ML20214F346
Person / Time
Site:	Byron
Issue date:	10/31/1986
From:	Farrar D COMMONWEALTH EDISON CO.
To:	James Keppler NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
References
2339K, NUDOCS 8705260038
Download: ML20214F346 (5)

Text

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, / 3 Commonwealth Edison i

4 One First National Plaza. Chicago, Illinois gc

\ / Address Reply to: Post Offce Box 767 k_/ Chicago,!!!inois 60690 0767 October 31, 1986 Mr. James G. Keppler Regional Administrator U.S. Nuclear Regulatory Cotanission Region III 799 Roosevelt Road Glen Ellyn, IL 60137

Subject:

Byron Station Unit 2 Response to I.E. Inspection Report No. 455/86024 NRC Docket No. 50-455

Reference:

September 24, 1986 letter from R. F. Warnick to Cordell Reed

Dear Mr. Keppler:

This letter concerns the routine safety inspection conducted by Messrs. J. M. Hinds, Jr., P. G. Brochman and R. M. Lerch and Mses. J. A.

Malloy and M. L. McCormick-Barger of your office on July 16 through September 12, 1986 of activities at Byron Station Unit 2. The referenced letter indicated that certain of our activites appeared to be in violation of NRC requirements. A one week response extension was obtained by telecon from M. A. Ring of your office on October 24, 1986. Commonwealth Edison Company's response to this issue is contained in the Attachment to this letter.

Commonwealth Edison Company has carefully reviewed this issue and has concluded that it has been improperly classified as s Severity Level V violation. The violation contends that the test procedure was inadequate in that it was approved without specifying the contafnment air density necessary for successful completion of the test.

The information provided in the Attachment conclusively demonstrates that the procedure specified and controlled the appropriate parameters necessary to ensure that containment air density was approximately equivalent to that following a loss of coolant accident. It further demonstrates that it is not feasible to postulate a containment air temperature that would result in unacceptable containment air densities during the performance of this test procedure.

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Mr. J. G. Keppler - October 31, 1986 Thus, Commonwealth Edison is requesting that you reconsider the classification of'this event in_ light of the information presented in the Attachment. We'are available to discuss this matter further at your convenience.

If any further questions arise concerning this matter, please contact this office.

Very truly yours, D. L. Farrar Director of Nuclear Licensing Im Attachment 4

cc: Eyron Resident Inspector L. N. Olshan ~ NRR i

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ATTAQWWIT BYRON STATION UNIT 2 RESPONSE TO NOTICE OF VIOLATION ITEM OF NONCOMPLIANCE As a result of the inspection conducted on July 16 though September 12, 1986, and in accordance with the " General Policy and Procedures for NRC Enforcement Actions," 10 CFR Part 2, Appendix C (1986), the following violation was identified:

10 CFR 50, Appendix B, Section XI, requires that all. testing

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necessary to demonstrate that components will perform satis-factorily be accomplished in accordance with written test procedures.

Byron FSAR Section 6.2.2.4.1.d requires that the Reactor Containment Fan Cooler (RCFC) system 1,e demonstrated capable of operating air densities approximately equivalent to that following_a loss-of-coolant accident.

-Containment Ventilation Test 2.93.62 implemented these requirements.

Contrary to the above, on July 9, 1986, test 2.93.62 was approved without specifying the containment air density necessary to demonstrate that the RCFCs would perform satisfactorily for conditions approximately equivalent to that following a loss-of-coolant accident, (Note: By observation and discussion with the licensee, it was determined that the necessary data had been taken and that the necessary calculations had been performed for both Units 1 and 2.

CORRECTIVE ACTION TAKEN AND RESULTS ACHIEVED Test procedures 2.93.62 has been carefully reviewed.. The conclusion of this review is that the test procedure properly.specified and-controlled the. test conditions to ensure that the test objectives were.

successfully satisfied. This conclusion.is based 1upon the discussion that-follows.

The violation contends that test procedure "2.93.62 was approved without specifying the containment air density necessary to demonstrate that the RCFCs would perform satisfactorily for conditions-aproximately-equivalent to that following a loss-of-coolant accident." (Emphasis added.)

The observable containment parameters most directly related to containment air density are containment air pressure and containment air temperature.

l Test Procedure 2.93.62 clearly specified the appropriate containment.

air pressure in the four following locations;

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Step 7.7.1'specified one of.the test's initial condit' ions as being containment--pressure between 24-and 27 psig.

2. Step 9.0.4 included a general test condition of containment air pressure between 24 and 27 psig.

3 .' A procedural note at!'the beginning of test section 9.1 repeated the 24 to 27 psig requirement.

4. - Step 9.1.1~ required the verification that the air pressure remained within the 24 to 27.psig range.

containment air temperature was not specified in.the body of the procedure, since there is no means of significantly altering the average containment air temperature. .However, the expected range of the air temperatures was specified.

More importa'ntly, containment air temperature is not the controlling parameter for containment air density._ The tightly-controlled air pressure is the observable parameter that determines the existence of containment air densities that are approximately equivalent to the_ nominal, post-LOCA densities.

A parametric study has been performed to support this belief. A summary of result is tabularized below.

VARIATION OF CONTAINMENT-AIR DENSITY Air Ai Press.

Temp psig

(*P) 24 psig 27 psic 40*F .2084 lb .2245 lba-ft 3 ft 3

+10.2% from nominal +18.8% from nominal

-120*F .1782 1hm . .1922 1he ft 3 ft 3

-5.7% from non.inal. +1.7% from nominal 180*F .1570 lba -

.1696 1he ft 3- ft3-

-16.9% from nominal -10.2% from nominal-Nominal Post-14CA density = .189 WR ft 3

The maximum possible variation over'the expected test conditions (40 to 120'F) is only a total of 24% in air density. Clearly, this range is "approximately equivalent" to the nominal values.

In addition, even if one postulates an unrealistic value of 180'F for containment air temperature, the range of densities would only be 35%.

Thus, it is not feasible to postulate an unacceptable value.for containment air temperatures.

In summary, our review has concluded that' test procedure 2.93.62 specified and controlled the appropriate containment parameters to ensure the existence of the proper value of containment air density during the test.

CORRECTIVE ACTION TO BE TAKEN TO AVOID FURTHER VIOLATION No further action is required.

DATE WHEN FULL COMPLIANCE WILL BE ACHIEVED Byron Station is in compliance at this time.

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