ML20054F256

Final Deficiency Rept Re Steam Generator Tube Rupture FSAR Analysis,Initially Reported 820119.Item Does Not Meet Criteria for Reportability.No Corrective Action Necessary

ML20054F256
Person / Time
Site:	South Texas
Issue date:	06/10/1982
From:	Oprea G HOUSTON LIGHTING & POWER CO.
To:	Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, ST-HL-AE-834, NUDOCS 8206150418
Download: ML20054F256 (4)

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The Light Company n.,m,,, ugi,iii,a & i>~, im.,s imo n -,,,.,- ,,ooi omus.92n June 10, 1982 ST-HL-AE-834 SFN: V-0530 EQg @ y gilj{~ Ti i' l ' r- - - - -- --

J 'i Mr. John T. Collins !i ^

Regional Administrator, Region IV

\ .M I I IE .

Nuclear Regulatory Conmission [( jh;)

611 Ryan P1aza Dr. , Suite 1000 Arlington, Texas 76012 E

Dear Mr. Collins:

South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning Westinghouse Steam Generator Tube Rupture Analysis On January 19, 1982, Houston Lighting & Power Company (HL&P), pursuant to 10CFR50.55(e), notified your office of an item concerning the existing Steam Generator Tube Rupture (SGTR) analysis which was performed by Westinghouse (W). Please find attached our final report on this subject.

If you should have any questions concerning this item, please contact Mr. Michael E. Powell at (713) 877-3281.

Very truly yours, j-l

,/ I p.ea,a r.

7 Executive Vice resident GWO/MEP/kr Attachment N

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7 8206150418 020610 DR ADOCK 05000498 PDR

i o llouston 1.ighting & Power Company

~cc: G. W. Oprea, Jr. June 10, 1982 J. H. Goldberg ST-HL-AE 834 J. G. Dewease SFN: V-0530 J. D. Parsons Page 2 D. G. Barker C. G. Robertson R. A. Frazar J. W. Williams J. W. Briskin J. E. Geiger R. L. Ulrey S. M. Dew J. T. Collins (NRC)

D. E. Sells (NRC)

W.- M. Hill , J r. (NRC)

M. D. Schwarz (Baker & Botts)

R. Gordon Gooch (Baker &Botts)

J. R. Newman (Lowenstein, Newman, Reis, & Axelrad)

STP RMS Director, Office of Inspection & Enforcement Nuclear Regulatory Commission Washington, D. C. 20555 G. W. Muench/R. L. Range Charles Bechhoefer, Esquire Central Power & Light Company Chairman, Atomic Safety & Licensing Board P. O. Box 2121 U. S. Nuclear Regulatory Comission Corpus Christi, Texas 78403 Washington, D. C. 20555 H. L. Peterson/G. Pokorny Dr. James C. Lamb, III City of Austin 313 Woodhaven Road P. O. Box 1088 Chapel Hill, North Carolina 27514 Austin, Texas 78767 J. B. Poston/A. vonRosenberg Mr. Ernest E. Hill City Public Service Board Lawrence Livennore Laboratory P. O. Box 1771 University of California San Antonio, Texas 78296 P. O. Box 808, L-46 ,

Livermore, California 94550 Brian E. Berwick, Esquire William S. Jordan, III Assistant Attorney General Harmon & Weiss for the State of Texas 1725 I Street, N. W.

P. O. Box 12548 Suite 506 Capitol Station Washington, D. C. 20006 Austin, Texas 78711 Lanny Sinkin Citizens for Equitable Utilities, Inc.

Citizens Concerned About Nuclear Power c/o Ms. Peggy Buchorn 5106 Casa Oro Route 1, Box 1684 San Antonio, Texas 78233 Brazoria, Texas 77422 Jay Gutierrez, Esquire Hearing Attorney Office of the Executive Legal Director V. S. Nuclear Regulatory Commission Washington, D. C. 20555 Revision Date 04-19-82

Final Report Concerning the Westinghouse Steam Generator Tube Rupture Analysis I.

SUMMARY

The accident scenario in question is the Steam Generator Tube Rupture (complete severance of one tube) concurrent with a loss of offsite power.

The analysis as presented in FSAR Section 15.6.3.2 indicates that the break flow from the primary side to the secondary side can be terminated within thirty (30) minutes after initiation of the accident. The mechanism used to terminate the break flow is the depressurization of the primary side to a pressure less than or equal to the set pressure of the main steam safety valves.

Initially there was a concern that the system design did not meet the assumptions used for the FSAR analysis. However, further investigation revealed that the design does provide the features necessary to meet the assumptions of the FSAR analysis. Since the criteria and bases of the FSAR are supported by the design this item does not meet the criteria for reportability pursuant to 10CFR50.55(e).

II. DESCRIPTION OF INCIDENT 19 1982, Houston Lighting & Power Company (HL&P), pursuant to On January (e),, notified your office of an item concerning the Steam 10CFR50.55 Generator Tube Rupture (SGTR) analysis which was perfonned by Westinghouse (W) and is referenced in FSAR Section 15.6.3.

The accident scenario in question is the SGTR (complete severance of one tube) concurrent with a loss of offsite power. The FSAR analysis assumes the primary side can be depressurized within 30 minutes. This can be accomplished by either (1) utilizing nonnal utilizing auxiliary pressurizer spray or (3) pressurizer spray, utilizing the (2) pressurizer

PORV's.

For the scenario of a loss of offsite power condition, the Reactor Coolant Pumps (RCP's) will not be running and therefore nonnal pressurizer spray is not available. Use of the auxiliary pressurizer spray and the pressurizer PORV's requires use of air operated valves. A loss of offsite power would result in the loss of air to these valves rendering them inoperable. Powering the instrument air compressors from an emergency power supply would allow operation of the valves required for depressurization of the primary side within the time frame established in the FSAR SGTR analysis.

In the STP design there is a non-Class 1E B0P diesel generator that is used primarily for equipment protection. The instrument air compressors can be manually transferred to the B0P diesel generator by means of a local switch. Both Bechtel Power Corporation (BPC) and W have reviewed the integrity and availability of the instrument air system while the

> *e instrument air compressors are being powered from the 80P diesel during the loss of offsite power condition. Their conclusion is that this source of power would permit use of the pressurizer PORV to reduce primary pressure and that the design does meet the analysis assumptions.

Therefore, HL&P concludes this item does not meet the criteria for reportability and submits this Final Report as closure for the item.

III. CORRECTIVE ACTION Because this item does not meet the criteria for reportability no corrective action is necessary.

IV. RECURRENCE CONTROL A recurrence control program is not considered necessary.

V. SAFETY ANALYSIS A complete safety analysis of this incident is provided in FSAR Section 15.6.3. The resultant offsite doses calculated using both realistic and conservative assumptions are provided in FSAR Table 15.6-4 and are significantly less than the guidelines of 10CFR100.