GO2-83-953, Interim Deficiency Rept 288 Re Partial Removal of Sand Pocket Between Shield Wall & Containment.Reanalysis Performed to Assess Effect of Removing Sand.Results Expected by 831119

Interim Deficiency Rept 288 Re Partial Removal of Sand Pocket Between Shield Wall & Containment.Reanalysis Performed to Assess Effect of Removing Sand.Results Expected by 831119

ML20081H843
Person / Time
Site:	Columbia
Issue date:	10/21/1983
From:	Carlisle C WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
10CFR-050.55E, 10CFR-50.55E, 288, G2-83-953, GO2-83-953, NUDOCS 8311070607
Download: ML20081H843 (2)

Text

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g Washington Public Power Supply System P. Box 968 3000 GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000

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g., October 21, 1983

$c, G02-83-953 EE E5 g b

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b 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 N0. 2 10CFR50.55(e) REPORTABLE CONDITION #288 SAND P0CKET REMOVAL

Reference:

Telecon QA2-83-215, dated October 6, 1983, R.T. Johnson to D. Haist, same subject.

In accordance with the provisions of 10CFR50.55(e), your office was informed by the reference above of the subject condition. The attachment provides the Project's interim report on Condition #288.

If there are any questions concerning this matter, please contact Roger Johnson, WNP-2 Project QA Manager, (509) 377-2501, extension 2712.

t-

. . Carlisle Program Director, WNP-2 RTJ/kd

Attachment:

As stated cc: W.S. Chin, BPA N.D. Lewis, EFSEC A. Toth, Resident Inspector Document Control Desk, NRC hM S

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• WASHINGTON PUBLIC POWER SUPPLY SYSTEM NUCLEAR PROJECT N0. 2 DOCKET N0. 50-397 LICENSE N0. CPPR-93 .

10CFR50.55(e) CONDITION #288 SAND POCKET REMOVAL INTERIM REPORT Description of Deficiency A sand pocket between the biological shield wall and the containment, between elevation 443'-0" and 446'-0", was at least partially removed by water hose in order to break up cemented sand and allow drainage. Probably less than 10% of the total volme of sand was removed. The exact quantity is not known.

Also, the distribution of sand removal is not known, but it is possible that the entire 3-foot depth at the location of the drains was removed, while areas between the drains may not have been disturbed.

Safety Implication The stress report for the containment shell takes credit for the sand in re-ducing stress intensity in the containment shell. The top of the sand pocket on the outside of the containment is at the same elevation as the top of the concrete placed on the inside of the containment, within which the bottom

" dish" of the containment is embedded. Vertical tee stiffeners on the inside of the containment vessel are embedded in this concrete, and thus provide restraint against outward radial deflection of the containment due to postu-lated loading. The sand also provides restraint against outward deflection.

Containment vessel stress in this area was analyzed using a finite element model of the containment, vertical stiffeners, concrete, and sand.

With the sand removed, deflection of the containment under postulated loading will be different than the condition analyzed, and therefore, the stress dis-tribution will be different. A reanalysis is required to determine whether ASME Section III design requirements are met with the sand removed.

Cause of the Deficiency The sand was removed by direction of the Architect-Engineer, in accordance with previous dicussions and agreements with the Supply System to resolve the sand drainage problem. The sand was originally installed in accordance with design drawings, for constructability reasons and not as a feature required by structural analysis. Authorization to remove the sand received concurrence from the Arichitect Engineer's home office. However, the authori-zation to remove the sand was granted without the knowledge of individuals who had reviewed the containment stress report.

Corrective Action A reanalysis is being performed to assess the effect of removing the sand from the sand pocket. This reanalysis is being performed by the consultant who performed the original finite element analysis of the containment in the area of the sand pocket. Results of this reanalysis are expected by October 19, 1983.

Action to Prevent Recurrence No action to prevent recurrence is required.