ML14183A774
| ML14183A774 | |
| Person / Time | |
|---|---|
| Site: | Robinson  |
| Issue date: | 11/27/1996 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML14183A773 | List: |
| References | |
| TAC-M96564, NUDOCS 9612040203 | |
| Download: ML14183A774 (2) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE THIRD 10-YEAR INTERVAL INSERVICE INSPECTION REQUEST TO DELETE RELIEF NO.13 FOR CAROLINA POWER & LIGHT COMPANY H. B. ROBINSON STEAM ELECTRIC PLANT, UNIT NO. 2 DOCKET NUMBER: 50-261 BACKGROUND:
In a letter dated August 1, 1991, Carolina Power and Light Company (CP&L) submitted specific relief requests from the requirements of the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel (B&PV) Code,Section XI, (the Code) for the Third Ten-Year Interval Inservice Inspection (ISI)
Program Plan for the H. B. Robinson Steam Electric Plant, Unit No. 2 (HBR). One of those relief requests was Relief Request No. 13 (RR13).
RR13 included proposed alternative methods to performing the volumetric examination of reactor coolant pump (RCP) casing welds (i.e., Examination Category B-L-1, "Pressure Retaining Welds in Pump Casings," Item 12.10), and from visual (i.e., VT-3) examination of the internal surfaces of the RCP casing (i.e.,
Examination Category B-L-2, "Pump Casings," Item 12.20).
In a letter dated October 19, 1992, the NRC issued its Safety Evaluation (SE) for the Third Ten-Year Interval ISI Program Plan conditionally granting RR13.
The condition for the NRC staff's approval of RR13 was to require an ASME B&PV Code VT-3 visual examination of the internal surfaces of the pump and a volumetric examination of the pump interior casing welds if an RCP is disassembled for repair or maintenance.
In a letter dated September 19, 1996, the licensee requested one-time relief from the described condition and proposed not to perform volumetric and VT-3 visual examinations because the interior surface of the pump casing will not be made accessible by a full disassembly of the RCP, and the licensee wanted to avoid excessive radiation dose exposure. The request for relief was submitted because early in the current Refueling Outage (RO) 17, during disassembly of drip pans for the "A" RCP, accumulation of boron precipitation was observed on "A" RCP flange studs. This indication was later evaluated as a leak in the "A" RCP main flange gasket. The licensee's plan was to partially disassemble the "A" RCP as necessary to perform the needed repairs to RCP studs and main flange gasket. The planned partial disassembly of the "A" RCP did not include disassembly of the pump casing internals and because of that the licensee could not satisfy the condition specified in the NRC staff's approval of RR13 dated October 19, 1992.
9612040203 961127 PDR ADOCK 05000261 G
-2 In a letter dated September 23, 1996, the licensee indicated that it no longer needed RR13 for the Third Ten-Year Interval ISI Program Plan, and withdrew its request of September 19, 1996, for a one-time NRC authorization to use the proposed alternative to the conditions specified in the NRC SE approving RR13.
The licensee also committed to meet the requirements of the 1986 edition of the ASME Code,Section XI, "Rules for Inservice Inspection of Nuclear Power Plant Components."
The 1986 edition of the ASME Code is the code of record for the Third Ten-Year Interval ISI Program Plan for HBR. In order to meet the ASME Code requirements the licensee intends to perform the RCP examinations specified in Examination Category B-L-1 "Pressure Examination Category B-L-2, "Pump Casings," Item 12.20 (i.e, visual, VT-3), of Table IWB 2500-1, "Examination Categories," within the Third Ten-Year Interval ISI Program Plan period. The licensee will also be submitting revised pages of the Third Ten-Year Interval ISI Program Plan to reflect the deletion of RR13.
EVALUATION:
The NRC staff has reviewed the licensee's request for withdrawal of RR13 for the Third Ten-Year Interval ISI Program Plan for HBR and has no objections to granting the request. As stated above, the licensee's Code of record for the Third Ten-Year Interval ISI Program Plan is the ASME Code 1986 edition. The licensee has committed to meet the Code and to submit revised pages of the Third Ten-Year Interval ISI Program Plan to reflect the deletion of RR13.
These actions satisfy the requirements of 10 CFR 50.55a(g).
Therefore, the relief granted for RR13 in the NRC SE dated October 19, 1992, is hereby rescinded because it is no longer needed.
However, it should be noted that the licensee stated in its September 19, 1996, submittal that it is considering future use of ASME Code Case N-481, "Alternate Examination Requirement for Cast Austenitic Pump Castings" for the HBR pumps. Code Case N-481 does not require volumetric examination of the pump casings and relies on the material evaluation of the casings to demonstrate the safety and serviceability of the pump casings. If the licensee adopts the Code Case for use at HBR, the pump casings will not be volumetrically examined as required by the ASME Code Section XI and, thus, information that could be obtained by the volumetric information will not be available.
In addition, because it is not apparent why compliance with the Code is no longer impractical for the facility, to the extent that the relief is not needed, this withdrawal may indicate potential problems concerning the implementation of HBR's ISI program, particularly with respect to 10 CFR 50.55a(g)(5) determinations. Thus, the NRC staff may conduct a staff audit to ascertain whether the licensee is implementing its ISI program in accordance with the ASME Code, the license commitments, and NRC requirements.
Principal contributor:
George Georgiev, ECGB/DE Date: November 27, 1996