NLS2018061, Request to Grant Emergent Relief from, and Authorize Alternative to Inservice Inspection Code Requirement
| ML18313A092 | |
| Person / Time | |
|---|---|
| Site: | Cooper  |
| Issue date: | 11/05/2018 |
| From: | Dent J Nebraska Public Power District (NPPD) |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NLS2018061 | |
| Download: ML18313A092 (5) | |
Text
H Nebraska Public Power District NLS2018061 November 5, 2018 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Always there when you need us
Subject:
10 CFR 50.55a Relief Request PR5-02 Cooper Nuclear Station, Docket No. 50-298, DPR-46
Dear Sir or Madam:
10 CFR 50.55a The purpose of this letter is for the Nebraska Public Power District (NPPD) to request that the Nuclear Regulatory Commission (NRC) grant emergent relief from, and authorize alternative to, an inservice inspection code requirement for Cooper Nuclear Station (CNS) pursuant to 10 CFR 50.55a. The 10 CFR 50.55a request pertains to inservice examination test requirements in
.Section XI of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code.
Relief Request PR5-02, attached to this letter, will be used for the duration of the fifth ten-year inservice inspection tnterval. NPPD requests approval of this Relief Request today, November 5, 2018, to support startup from Refueling Outage 30, as discussed in a telephone conversation on the same date, between Tom Wengert, NRC Project Manager, and Jim Shaw, CNS Licensing Manager.
This letter contains no regulatory commitments.
Should you have any questions concerning this matter, please contact Jim Shaw, Licensing Manager, at (402) 825-2788.
Sincerely, Dent, Jr.
Vice President - Nuclear and Chief Nuclear Officer
/jo
Attachment:
PR5-02, Definition of Pressure Retaining Boundary for System Leakage Test COOPER NUCLEAR STATION P.O. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3811 / Fax: (402) 825-5211 www.nppd.com
NLS2018061 Page 2 of2 cc: Regional Administrator w/attachment USNRC - Region IV Cooper Project Manager w/attachment USNRC - NRR Plant Licensing Branch IV Senior Resident Inspector w/attachment USNRC-CNS NPG Distribution w/o attachment CNS Records w/attachment
NLS2018061 Attachment Page 1 of3 10 CFR 50.55a Request Number PRS-02 De:fmition of Pressure Retaining Boundary for System Leakage Test Proposed Alternative in Accordance with 10 CFR 50.55a(z)(2)
Hardship without a Compensating Increase in Quality or Safety American Society of Mechanical Engineers {ASME) Code Component{s) Affected Code Class:
Examination Category:
Item Number:
Component Numbers:
1 B-P B15.10 All Components Subject to Pressurization During a System Leakage Test
Applicable Code Edition and Addenda
ASME Code Section XI, 2007 Edition, 2008 Addenda
Applicable Code Requirement
Paragraph IWB-5222(a)
Article IWB-5000, "System Pressure Tests," Sub-subarticle IWB-5220, "System Leakage Test,"
Paragraph IWB-5222, "Boundaries," states that:
(a) The pressure retaining boundary during the system leakage test shall correspond to the reactor coolant boundary, with all valves in the position required for normal reactor operation startup. The visual examination shall, however, extend to and include the second closed valve at the boundary extremity.
(b) The Class 1 pressure retaining boundary which is not pressurized when the system valves are in the position required for normal reactor startup shall be pressurized and examined at or near the end of each inspection interval. This boundary may be tested in its entirety or in portions and testing may be performed during the testing of the boundary IWB-5222(a).
Reason for Request
Pursuant to 10 CFR 50.55a, "Codes and Standards," Paragraph (z)(2), relief is requested from the requirements of ASME Code Section XI requirements for performing a system leakage test using the boundaries stated in Paragraph IWB-5222(a) because performing the pressure test with this boundary would result in a hardship without a compensating increase in quality and safety due to excessive radiation exposure and personnel safety concerns (temperature levels in the drywell).
NLS2018061 Attachment Page 2 of3 10 CFR 50.55a Request Number PRS-02 (continued)
Def1nition of Pressure Retaining Boundary for System Leakage Test Proposed Alternative and Basis for Use In lieu of a system leakage test during reactor startup, as required by IWB-5222(a), a system pressure test is performed at the pressure associated with 100% rated reactor power.
a)
The outboard Feedwater check valves and the High Pressure Coolant Injection (HPCI) and Reactor Core Isolation Cooling (RCIC) injection check valves are the Class 1 boundary valves and are closed for this test. The Feedwater check valves are normally open for reactor startup. The inboard check valve (RF-CV-16CV) on one F eedwater line is kept open by Reactor Water Cleanup (RWCU) flow. The RWCU system is kept in service during the pressure tests. Thus, the outboard Feedwater check valve and the RCIC injection check valve on this line will be pressurized during this test. The portion of piping between the other two Feedwater check valves including the HPCI injection line will not be pressurized.
b)
The four outboard Main Steam Isolation Valves (MSIV) will be closed for the system pressure test and the ten-year system pressure test [IWB-5222(b)]. The inboard MSIVs are opened to pressurize the system to the outboard valves. Both Main Steam Drain Valves are normally open to facilitate for pressure control; however, the outboard Class 1 boundary valve may be closed to provide leakage isolation if needed. The outboard valves are the Class 1 boundary valves.
c)
Both HPCI and both RCIC steam supply valves will be closed for the system pressure test following a refueling outage. These valves close automatically on low steam supply pressure. During the ten-year system pressure test [IWB-5222(b)], the system will be pressurized to the outboard valves. The outboard valves are the Class 1 boundary valves.
The position of the valves for the system leakage test as described above is consistent with the intent of IWB-5222(a). Abnormal lineups and installation of jumpers are not required for the system leakage test. The valves described above are normally open during a reactor startup. In order to pressurize the reactor coolant pressure boundary for testing, these valves must be closed.
Except as described above, the Class 1 boundary is pressurized as required by the code. The VT".'
2 inspection includes the entire reactor coolant pressure boundary.
Since the portions of the piping between the valves described above are operated at or above reactor pressure during normal operation, any through-wall leakage would be detected by the drywell leakage collection system, or by operations personnel on normal rounds.
NLS2018061 Attachment Page 3 of3 10 CFR 50.55a Request Number PRS-02 (continued)
Def"mition of Pressure Retaining Boundary for System Leakage Test Performing a system pressure test at 100 percent reactor power would result in a hardship without a compensating increase in quality and safety. At 100% power primary containment is inerted and radiation levels are high. The proposed alternative provides reasonable assurance of operational readiness of the subject components.
In summary, three of the Feedwater check valves, HPCI injection check valve, the outboard MSIVs, and the HPCI and RCIC steam supply valves will be closed during the system leakage test, but will be included in the VT-2 visual examination. A VT-2 examination will be performed during the system leakage test at a pressure not less than that associated with 100%
rated reactor power and will provide reasonable assurance of the continued operational readiness of mechanical connections, extending to the Class 1 boundary. In addition, once at or near the end of the inspection interval the system leakage test shall extend to the Class 1 boundary as required by IWB-5222(b ).
Based on the above, Nebraska Public Power District (NPPD) requests relief from the ASME Section XI requirements for performing a system leakage test using the boundaries stated in IWB-5222(a).
Duration of Proposed Alternative This proposed alternative will be used for the duration of the fifth ten-year inservice inspection interval.
Precedents PR-02, was previously approved by the Nuclear Regulatory Commission (NRC) for the fourth ten-year interval for Cooper Nuclear Station (CNS) on October 2, 2006 (ML062260195).
References
- 1. NPPD Letter NLS2006015 to USNRC dated February 23, 2006, "10 CFR 50.55a Requests for Fourth Ten-Year Inservice Inspection Interval."
- 3. USNRC letter to NPPD, dated October 2, 2006, "Cooper Nuclear Station Re: Fourth 10-Year Interval Inservice Inspection Request for Relief No. PR-02" (TAC NO. MD0284).