ML20058G157
| ML20058G157 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/29/1982 |
| 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-858, NUDOCS 8208030219 | |
| Download: ML20058G157 (4) | |
Text
'
The Light comPuy flouston ughiing & Power Po. Itox 170011ouston, Texas 77001 (713)228-9211 July 29, 1982 ST-HL-AE-858 File Number: G12.123 SFN: V-0530 Mr. John T. Collins
@'l Regional Administrator, Region IV l.-
Nuclear Regulatory Commission 611 Ryan Plaza Dr., Suite 1000
,Z.
Arlington, Texas 76012
'JJL 3 01982
Dear Mr. Collins:
l South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning an Unanalyzed Release Pathway Following a LOCA On July 1,1982, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning an unanalyzed release pathway of radioactivity to the environment following a postulated loss-of-coolant accident (LOCA). Attached is the Final Report which provides the corrective actions to be implemented.
j If you should have any questions concerning this item, please contact Mr. M. E. Powell at (713) 877-3281.
1 Very truly yours, p /
s,
'/
s phi #
Exec tive dce President MEP/kr Attachment h}
h 5
B20B030219 B20729 PDR ADOCK 05000498 S
llouston 1.igining & Power Company cc:
G. W. Oprea, Jr.
July 29, 1982 J. H. Goldberg ST-HL-AE-858 J. G. Dewease File Number: GI2.123 J. D. Parsons SFN: V-0530 D. G. Barker Page 2 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, Jr.
(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 Commission Corpus Christi, Texas 78403 Washington, D. C.
20555 H. L. Peterson/G. Pokorny Dr. Janes 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 Livernert Laboratory P. O. Box 1771 University of California San Antonio, Texas 78296 P. 0. 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 U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Revision Date 04-19-82
s Final Report Concerning an Unanalyzed Release Pathway Following a LOCA I.
Description of the incident On July 1,1932, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning an unanalyzed release pathway of radioactivity to the environment following a postulated loss-of-coolant accident (LOCA). This item was discovered in the review by Bechtel Power Corporation (BPC) of the Radioactive Vents & Drains System Work Package (Log No. EN-613).
A review of the documentation associated with the subject Work Package identified that the logic diagrams for the equipment and floor drain sumps shows the Safety Injection System (SIS)/ Containment Spray System (CSS) pump cubicle sump pumps to be automatically actuated by Hi and Hi-Hi level switches in the cubicle sumps.
Following a postulated LOCA, and during the recirculation mode, a passive failure of an SIS pump seal could result in leakage of post-LOCA recirculation fluids into the cubicle sump. With the assumptions that (1) the non-1E power to the cubicle sump pumps and instrumentation is not disrupted by the accident and, (2) since no safety related interruption of flow (interruption of pump power, pump actuation signal or valve closure) occurs, then the potential exists for transferring a minimum of 1500 gallons (50 GPM for 30 minutes) of post-LOCA recirculation fluids to the floor drain tank located in the Mechanical Auxiliary Building (MAB). Since the floor drain tank vents to the atmosphere through the plant vent header and is not served by an ESF charcoal filtration system, a pathway exists for an unanalyzed release of radioactivity to the environment following a LOCA.
II.
Corrective Action This concern will be corrected by revising the system design to preclude the automatic operation of the SIS / CSS cubicle sump pumps following a LOCA.
This design change will be documented in a future FSAR amendment.
III. Recurrence Control A recurrence control program is. not considered necessary because the situation is unique. No other sumps in the plant provide service to potentially leaking systems carrying post-LOCA recirculation fluids outside containment.
l l
IV. Safety Analysis An analysis has been completed which shows that for the design basis LOCA, the previously defined scenario results in an unfiltered release with a resulting dose greater than the 10CFR100 limit to the thyroid. The whole body dose is within limits. The conservatises of this analysis are based upon Revision 1 (July 1981) to the Standard Review Plan (SRP) Section 15.6.5, Appendix B, " Radiological Consequences of a Design Basis Loss-of-Coolant Accident: Leakage from Engineered Safety Feature Components Outside Containment", which states that (1) "For a plant that does not provide an ESF atmosphere filtration system, the dose assessment should also include the leakage from a gross failure of a passive component. This leakage should conservatively be assumed to be 50 gallons per minute, starting at 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the accident and lasting for 30 minutes." and (2) "the airborne iodine is assumed to be released inrediately to the environment".
1 4.
-. - - - - -