LR-N13-0263, License Renewal Commitment Implementation

License Renewal Commitment Implementation

ML13317B684
Person / Time
Site:	Salem
Issue date:	11/12/2013
From:	Jamila Perry Public Service Enterprise Group
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
LR-N13-0263
Download: ML13317B684 (6)

Text

PSEG Nuclear LLC P.O. Box 236, Hancocks Bridge, NJ 08038-0236 PSEG Nuclear IJ.C LR-N 13-0263 t",

FOL 2. C. 21 NOV 1 2 2013 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Salem Generating Station, Unit 1 Facility Operating License No. DRP-70 NRC Docket No. 50-272

Subject:

License Renewal Commitment Implementation In accordance with the renewed facility operating license condition 2.C.21, "PSEG Nuclear LLC shall take one core sample in the Unit 1 spent fuel pool west wall, by the end of 2013, and one core sample in the east wall where there have been indications of borated water ingress through the concrete, by the end of 2015. The core samples (east and west walls) will expose the rebar, which will be examined for signs of corrosion. Any sample showing signs of concrete degradation and/or rebar corrosion will be entered into the licensee's corrective action program for further evaluation. PSEG Nuclear LLC shall submit a report in accordance with 10 CFR 50.4 no later than three months after each sample is taken on the results, recommendations, and any additional planned actions."

The attached document contains the summary of the results, recommendations, and any additional planned actions for the first of the two required core samples as stated in the license condition 2.C.21.

There are no new commitments in this letter.

If there are any questions, please contact Thomas Cachaza at 856-339-5038.

Sincerely, f:LFf2z--

• John F. Perry Salem Site Vice P dent Attachments ( 1)

Document Control Desk Page 2 LR-N 13-0263 C W. Dean, Administrator- Region 1 J. Hughey, Licensing Project Manager- Salem P. Finney, USNRC Senior Resident Inspector- Salem P. Mulligan, Manager, IV, Bureau of Nuclear Engineering T. Cachaza, Salem Commitment Coordinator L. Marabella, Corporate Commitment Coordinator

Document Control Desk Page 1 LR-N 13-0263 Attachment 1 Findings of Salem Generating Station Unit 1 Core Bore of Spent Fuel Pool West Wall On August 13, 2013, the Salem Generating Station (Salem) removed a 2-ft long by 4-in diameter core from the Unit 1 Spent Fuel Pool (SFP) West Wall per Licensing Condition 2.C.21 of the Salem Unit 1 Renewed Operating License NPR-70. In addition, rebar was exposed to check for corrosion. The specific Licensing Condition is repeated below for reference.

PSEG Nuclear LLC shall take one core sample in the Unit 1 spent fuel pool west wall, by the end of 2013, and one core sample in the east wall where there have been indications of borated water ingress through the concrete, by the end of 2015. The core samples (east and west walls) will expose the rebar, which will be examined for signs of corrosion. Any sample showing signs of concrete degradation and/or rebar corrosion will be entered into the licensee's corrective action program for further evaluation. PSEG Nuclear LLC shall submit a report in accordance with 10 CFR 50.4 no later than three months after each sample is taken on the results, recommendations, and any additional planned actions.

Concrete Core Examination Per PSEG Letter No. LR-N10-0321, Response to NRC Request for Additional Information, dated August 3, 2010, related to the ASME Section XI, Subsection IWE Program and Structures associated with the Salem Nuclear Generating Station, Units 1 and 2 License Renewal Application, dated September 1, 2010 (ADAMS Accession No.

ML102500102), Salem proposed to examine the core using petrography and compressive strength testing.

The following discussions were extracted from a detailed report prepared by MPR Associates Inc. (

Reference:

MPR Associates Inc. Report No. 0108-0425-08, Salem Unit 1 Fuel Handling Building - Evaluation of Concrete Core and Exposed Reinforcement, dated November 4, 2013).

The location of the core was approximately 20 inches below the construction joint. After the core was removed, approximately 1-2 inches of the end facing the sump room (coated with an epoxy coating) was chipped away to prepare it for removal from the Radiation Control Area (RCA). This chipping action caused the core to fracture into two pieces. The piece closest to the sump room was approximately 9 inches long, and was free released to Concrete Research & Testing, LLC (CRT) for examination and testing.

The second piece, closest to the SFP, was approximately 15 inches long. During the release process of the second piece from the RCA, the Gamma Scan identified activation products Cobalt-58, Cobalt-60, and Cadmium-109, and fission products Cesium-137 and Rubidium-88. These activation and fission products have been confirmed to not be due to corrosive borated water as the concrete showed no signs of

Document Control Desk Page 2 LR-N 13-0263 degradation as documented in the MPR Associates, Inc. Report No. 0108-0425-08.

Therefore, this portion of the core could not be free released, and was shipped to the Babcock & Wilcox Technical Services Group (B&W), a facility licensed to handle radioactive materials, for petrographic examination and compressive strength testing.

The CRT petrographer traveled to the B&W facility to perform petrographic examination of the second piece of the core. The results for each portion of the core are summarized in Table 1.

Table 1 Summary of Salem Unit 1 Spent Fuel Pool West Wall Concrete Core Results Core Compressive Piece No. Strength (1> Petrography by CRT (2>

Concrete is in good condition. The cement paste did not exhibit any features that would indicate that it had been 1 8,140 psi (3> affected by chemical attack (i.e., discoloration, softening, degradation, or dissolution).

Concrete is in good condition. The cement paste did not exhibit any features that would indicate that it had been 2 4, 733 psi (4> affected by chemical attack (i.e., discoloration, softening, degradation, or dissolution).

Table 1 Notes:

(1)

Compressive strength testing was performed in accordance with ASTM Standards C39 and C42.

(2) Concrete samples were prepared for petrographic examination in accordance with ASTM Standard C856. Three (3) specimens were taken from the core (front, middle, and back). Visual examinations were performed on each specimen following the guidelines of ASTM C856.

(3 ) Compressive strength was obtained from loading the Piece No. 1 to failure.

(4) The strength exhibited is based on the test apparatus maximum loading capability which limited the test results. The piece did not fail at this maximum loading, which was held for 10 seconds, indicating that the compressive strength exceeded 4, 733 psi.

The design compressive strength for concrete in the Fuel Handling Building is 3,500 psi.

The compressive strength results of both Core Pieces exceeded the design value.

Other specific observations of core specimens are noted below:

Document Control Desk Page 3

Document Control Desk Page 3 LR-N13-0263 CRT examined the fracture surface between the two pieces of the core. There were no signs of weakness in the concrete (e.g., from chemical attack) that would have caused the fracture.

Core Piece No. 1 exhibited a single crack that was oriented parallel to the core (lengthwise). The crack was present from the front, fractured surface of the core piece and extended to a length of 2. 75 inches from the fractured surface of the core. The maximum width of this crack was 0.04 mm (0.0016 inches). The crack may be related to drying shrinkage or may have been induced due to the force exerted by chipping away the 1-2 inches of the front end. In either case, the concrete in the area of this crack exhibited no signs of degradation related to the ingress of borated water, and would have been an insignificant impact on the structural performance of the Unit 1 Fuel Handling Building.

Therefore, the concrete core sample exhibited no signs of degradation.

Exposed Rebar Examination In addition to the core sample, Salem excavated a small area of the West Wall in the vicinity of the lateral construction joint to expose a portion of the reinforcing steel rebar.

The excavation area was approximately 16 inches below the construction joint, or about 4 inches above the core location and was approximately 4 inches by 4 inches and exposed one (1) section of rebar.

The excavation exposed a length of approximately 4 inches of the steel rebar. A visual examination of the exposed rebar was performed. Corrosion of the rebar was limited to minor surface corrosion that did not affect rebar thickness. The minor surface corrosion could be attributed to exposure to the environment during original construction, or recent exposure to the atmosphere for this specific inspection and subsequent wetting of the area to prepare for repair of the concrete to restore it to its original condition.

Therefore, the findings from the visual examinations performed on the exposed steel rebar indicated that the rebar showed no signs of aging-related corrosion.

There were no corrective actions taken to address any aging-related degradation of the concrete or rebar. However, during excavation to expose the rebar, portions of the exposed rebar were nicked by a power tool. A notification was entered into PSEG Nuclear's corrective action program and was dispositioned accordingly through a technical evaluation. No further actions are required by PSEG Nuclear.

Summary The removal and examination of the core sample in the Unit 1 spent fuel pool west wall did not show any indications of concrete degradation due to borated water ingress through the concrete. Also, the exposed rebar did not show signs of aging-related corrosion.

Document Control Desk Page 4 LR-N13-0263 There were no recommendations or additional planned actions (other than the removal of the second core) resulting from the examination of the first spent fuel pool core bore.

The 2013 actions required by the Salem Unit 1 Operating License NPR-70, License Condition 2.C.21 are completed.

The second concrete core will be removed from the Unit 1 East Wall prior to the end of 2015 for petrographic examination. This activity will also excavate and expose rebar in the vicinity of the removed core.