ML20083E989
| ML20083E989 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 12/14/1983 |
| From: | Sorensen G WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V) |
| References | |
| REF-PT21-84-131-000 10CFR-50.55E, 299, GO2-83-1162, PT21-84-131, PT21-84-131-000, NUDOCS 8312300078 | |
| Download: ML20083E989 (2) | |
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f7t Washington Public Power Supply;p#rerstem P.O. Box 968 3000 GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 033 EC IO UI E' '53 December 14, 1983 G02-83-ll62 3EGf Sil V it..!
Mr. J. B. Martin Regional Administrator U.S. Nuclear Regulatory Commission Region V 1450 Maria Lane, Suite 210 Walnut Creek, California 94596
Subject:
NUCLEAR PROJECT NO. 2 10CFR50.55(e) CONDITION #299 ROOM PFESSURIZATION DUE TO HIGH ENERGY LINE BREAKS
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References:
- 1. Letter BRGO-R0-83-013, dated September 29, 1983, W.G.
Conn to Office of Inspection and Enforcement.
- 2. Letter BRG0-R0-83-015, dated November 18, 1983, W.G. Conn to Office of Inspection and Enforcement.
In accordance with the provisions of 10CFR21, the Commission was informed of the subject condition by the above references. The attachment provides the Project's final report under the provisions of 10CFR50.55(e) on Condition #299.
If there are any questions concerning this matter, please contact Roger
' Johnson, WNP-2 Project QA Manager, (509) 377-2501, extension 2712.
G. C. Sorensen Manager, Regulatory Programs JGT/kd
Attachment:
As stated cc:
W.S. Chin, BPA N.D. Lewis, EFSEC A. Toth, Resident Inspector Document Control Desk, NRC i
8312300078 831214
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PDR ADOCK 05000397 Ilf j -[7 S
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WASHlNGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT NO. 2 DOCKET N0. 50-397 LICENSE NO. CPPR-93 10CFR50.55(e) CONDITION #299 ROOM PRESSURIZATION DUE TO HIGH ENER3Y LIHE BREAKS FINAL REPORT-Description of Deficiency Plant modifications implemented for fire protection and other concerns, included blocking of some vent paths from Reactor Building rooms containing high energy lines. Room pressurization calculations were not updated to reflect the revised venting capability.
Safety Implication Decreased vent area results in higher room pressure following a High Energy Line Break (HELB) which could cause wall / floor failure with attendant damage to safety related components.
The condition is, therefore, considered report-able under 10CFR50.55(e) and Part 21 criteria.
Cause of Deficiency Failure to recognize that reducing room vent paths could have adverse safety io.31icati ons.
Corrective Action
, All Reactor Building Rooms containing high energy lines were evaluated as to vent area changes. Six rooms were determined to require analysis.
The reanalysis has shown that one room (R206C) cannot withstand calculated pres-surization following a postulated high energy line break (HELB). This room is actually.a pipe chase that has one cement block wall for shielding purposes.
Pressurization following a HELB would cause the block wall to fail, impacting primarily electrical conduit.
Failure of the block wall in no way affects struc-tural integrity of the building.
A safe shutdown analysis has been performed assuming the loss of safety relatec equipment that would be impacted by the falling cement blocks coupled with the loss of an additional worse case single active component. The analysis indi-cated that the event would preclude safe shutdown. Burns and Roe has, there-fore, issued Project Engineering Jirective, PED 210A-CS-0743, to permanently remove the top 5'-0" of the existing block shield wall around tne pipe chase to provide adequate vent area.
Work is in progress and is scheduled to be complete in time to meet plant opera-tional requirements.
Action to Prevent Recurrence Group Supervisors have been advised that changes to room vent areas require consideration as to potential effect on room pressurization calculations.
The Plant design is complete and in lieu cf the complete review of the React a Building to evaluate changes in vent area, no other action to prevent recurre m is considered necessary.