ML17104A110
| ML17104A110 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 04/26/2017 |
| From: | Markley M T Plant Licensing Branch II |
| To: | Simril T Duke Energy Carolinas |
| Mahoney M, NRR/DORL/LPLII-1, 415-3867 | |
| References | |
| CAC MF9595, CAC MF9596 | |
| Download: ML17104A110 (9) | |
Text
Mr. Tom Simril Site Vice President UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 April 26, 2017 Catawba Nuclear Station, Units 1 and 2 Duke Energy Carolinas, LLC 4800 Concord Road York, SC 297 45
SUBJECT:
CATAWBA NUCLEAR STATION, UNITS 1AND2 -REQUEST FOR RELIEF NO. CN-GRR-01, ALTERNATIVE TO THE ASME OM CODE, BY ADOPTION OF CODE CASE OMN-20, "INSERVICE TEST FREQUENCIES" FOR THE FOURTH 10-YEAR INSERVICE TESTING INTERVAL (CAC NOS. MF9595 AND MF9596)
Dear Mr. Simril:
By letter dated April 11, 2017, Duke Energy Carolinas, LLC (Duke Energy, the licensee) submitted relief request CN-GRR-01 for use of an alternative to the testing frequencies in the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) Code, by adoption of approved Code Case OMN-20, "lnservice Test Frequency," for the fourth 10-year inservice testing (IST) interval, which is currently scheduled to end August 19, 2025, for the Catawba Nuclear Station (CNS), Units 1 and 2. Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.55a(z)(2), the licensee requested to use the proposed alternative since complying with the current ASME OM Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the subject relief request and concluded that the proposed alternative provide reasonable assurance that the affected components are operationally ready. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(a)(z)(2).
Therefore, the NRC staff authorizes the use of CN-GRR-01 for the remainder of the fourth 10-year IST interval at CNS, Units 1, and 2 which is currently scheduled to end August 19, 2025. All other ASME OM Code requirements for which relief was not specifically requested and approved in this request for relief remain applicable.
The details of the NRC review are provided in the enclosed safety evaluation.
T. Simril If you have any questions, please contact the Project Manager, Michael Mahoney at 301-415-3867 or via e-mail at Michael.Mahoney@nrc.gov.
Docket Nos. 50-413 and 50-414
Enclosure:
Safety Evaluation cc w/encl: Distribution via ListServ Sincerely, Michael T. Markley, Chief Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION FOURTH 10-YEAR INSERVICE TESTING PROGRAM INTERVAL REQUEST FOR RELIEF NO. CN-GRR-01 CATAWBA NUCLEAR STATION. UNITS 1 AND 2
1.0 INTRODUCTION
DUKE ENERGY CAROLINAS.
LLC. DOCKET NOS. 50-413 AND 50-414 By letter to the U.S. Nuclear Regulatory Commission (NRC) dated April 11, 2017 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 17103A 182), Duke Energy Carolinas, LLC (Duke Energy), the licensee, submitted relief request no. CN-GRR-01 for use of an alternative request to the testing frequencies in the American Society of Mechanical Engineers (ASME) Operation and Maintenance (OM) Code, by adoption of approved Code Case OMN-20, "lnservice Test Frequency," for the fourth 10-year inservice testing (IST) interval, which is currently scheduled to end August 19, 2025, for the Catawba Nuclear Station (CNS), Units 1 and 2. Pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.55a(z)(2), the licensee requested to use the proposed alternative since complying with the current ASME OM Code requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
2.0 REGULATORY EVALUATION
Paragraph 1 O CFR 50.55a(f), "lnservice Testing Requirements," requires, in part, that IST of certain ASME Code Class 1, 2, and 3 components must meet the requirements of the ASME OM Code and applicable addenda, except where alternatives have been authorized pursuant to paragraphs 10 CFR 50. 55a(z)( 1) or 10 CFR 50. 55a(z)(2).
In proposing alternatives, a licensee must demonstrate that the proposed alternative provides an acceptable level of quality and safety (10 CFR 50.55a(z)(1))
or compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety (10 CFR 50.55a(z)(2)).
Enclosure Based on the above, and subject to the following technical evaluation, the NRG staff finds that regulatory authority exists for the licensee to request and the Commission to authorize the alternative requested by the licensee.
3.0 TECHNICAL
EVALUATION
3.1 Relief
Request No. CN-GRR-01 3.1.1 ASME Code Components Affected All Pumps and Valves contained within the IST program scope. 3.1.2 Applicable Code Edition and Addenda The 2004 Edition with the 2006 Addenda of the ASME OM Code. 3.1.3 Applicable Code Requirements This alternative request is related to the test frequency requirements for pumps and valves applicable to ASME OM Division 1, Section IST 2009 Edition through OMa-2011 Addenda and all earlier editions and addenda of the ASME OM Code. 3.1.4 Reason for Request By letter dated April 11, 2017, the licensee stated, in part, that: The IST Program controls specified in Section 5.5 of TS [Technical Specifications]
provide: a) a table specifying certain IST frequencies; b) an allowance to apply SR 3.0.2 to inservice tests required by the OM Code and with frequencies of two years or less; c) an allowance to apply SR [Surveillance Requirement]
3.0.3 to inservice tests required by the OM Code; and d) a statement that, "Nothing in the ASME OM Code shall be construed to supersede the requirements of any TS." In Regulatory Issue Summary (RIS) 2012-10, "NRG Staff Position on Applying Surveillance Requirement 3.0.2 and 3.0.3 to Administrative Controls Program Tests," and EGM [Enforcement Guidance Memorandum]
2012-001, "Dispositioning Noncompliance with Administrative Controls Technical Specifications Programmatic Requirements that Extend Test Frequencies and Allow Performance of Missed Tests," the NRG stated that items b, c, and d of the TS IST Program were inappropriately added to the TS and may not be applied (although the EGM allows licensees to continue to apply those paragraphs pending a generic resolution of the issue). In RIS 2012-10 and EGM 2012-001, the NRG stated that the current TS allowance to apply SR 3.0.2 and SR 3.0.3 to the lnservice Testing Program would no longer be permitted.
In response, OMN-20, which provides allowances similar to SR 3.0.2, was approved and is proposed to be used as an alternative to the test periods specified in the OM code. The proposed alternative substitutes an approved Code Case for the existing TS requirements that the NRG has determined are not legally acceptable as a TS allowance.
This proposed alternative provides an equivalent level of safety as the existing TS allowance, while maintaining consistency with 10 CFR 50.55a and the ASME OM Code. 3.1.5 Proposed Alternative and Basis By letter dated April 11, 2017, the licensee stated, in part, that: The proposed alternative is OMN-20, "lnservice Test Frequency," which addresses testing periods for pumps and valves specified in ASME OM Division 1, Section IST, 2009 Edition through OMa-2011 Addenda and all earlier editions and addenda of ASME OM Code. This request is being made in accordance with 10 CFR 50.55a(z)(2), in that the existing requirements are considered a hardship without a compensating increase in quality and safety for the following reasons: 1) For IST testing periods up to and including 2 years, Code Case OMN-20 provides an allowance to extend the IST testing periods by up to 25%. The period extension is to facilitate test scheduling and considers plant operating conditions that may not be suitable for performance of the required testing (e.g., performance of the test would cause an unacceptable increase in the plant risk profile due to transient conditions or other ongoing surveillance, test or maintenance activities).
Period extensions are not intended to be used repeatedly merely as an operational convenience to extend test intervals beyond those specified.
The test period extension and the statements regarding the appropriate use of the period extension are equivalent to the existing TS SR 3.0.2 allowance and the statements regarding its use in the SR 3.0.2 Bases. Use of the SR 3.0.2 period extension has been a practice in the nuclear industry for many decades and elimination of this allowance would place a hardship on CNS when there is no evidence that the period extensions affect component reliability.
- 2) For IST testing periods of greater than 2 years, OMN-20 allows an extension of up to six months. The ASME OM Committee determined that such an extension is appropriate.
The six-month extension will have a minimal impact on component reliability considering that the most probable result of performing any inservice test is satisfactory verification of the test acceptance criteria.
As such, pumps and valves will continue to be adequately assessed for operational readiness when tested in accordance with the requirements specified in 10 CFR 50.55a(f) with the frequency extensions allowed by Code Case OMN-20. 3) As stated in EGM 2012-001, if an lnservice Test is not performed within its frequency, SR 3.0.3 will not be applied. The effect of a missed lnservice Test on the Operability of TS equipment will be assessed under the licensee's Operability Determination Program. 3.1.6 Duration of Proposed Alternative The proposed alternative is requested for the current 10 year IST interval or until Code Case OMN-20 is incorporated into a future revision of Regulatory Guide 1.192, referenced by a future revision of 10 CFR 50.55a, whichever occurs first. 3.2 NRC Staff Evaluation Licensees have applied and the NRC staff has accepted the standard TS definitions for IST intervals (including allowable interval extensions) to ASME OM Code-required testing (see Section 3.1.3 of NUREG-1482, Revision 2, "Guidelines for lnservice Testing at Nuclear Power Plants: lnservice Testing of Pumps and Valves and lnservice Examination and Testing of Dynamic Restraints (Snubbers) at Nuclear Power Plants," dated October 2013, ADAMS Accession No. ML 13295A020).
Recently, the NRC staff reconsidered the allowance of using TS testing intervals and interval extensions for IST not associated with TS SRs. As noted in Regulatory Issue Summary (RIS) 2012-10, "NRC Staff Position on Applying Surveillance Requirements 3.0.2 and 3.0.3 to Administrative Controls Program Tests," dated August 23, 2012 (ADAMS Accession No. ML 12079A393), the NRC determined that programmatic test frequencies cannot be extended in accordance with the TS SR 3.0.2. This includes all IST described in the ASME OM Code not specifically required by the TS SRs. Catawba Nuclear Station (CNS), Units 1 and 2 proposes to use the ASME OM Code Case OMN-20 as published in the ASME OM Code 2012 Edition. The 2012 edition of the ASME OM Code was approved by the ASME Board on Nuclear Codes and Standards.
ASME OM-2012 was also approved by the American National Standards Institute on December 21, 2012. Code Case OMN-20 will be used for determining acceptable tolerances for pump and valve testing frequencies.
The code case as published in ASME OM Code, 2012 Edition, is repeated below. Published OMN-20 Code Case ASME OM Division 1: Section /ST and earlier editions and addenda of ASME OM Code specify component test frequencies that are based either on elapsed time periods (e.g., quarterly, two years, etc.) or on the occurrence of plant conditions or events (e.g., cold shutdown, refueling outage, upon detection of a sample failure, following maintenance, etc.). (a) Components whose test frequencies are based on elapsed time periods shall be tested at the frequencies specified in Section /ST with a specified time period between tests as shown in Table 1 (below). The specified time period between tests may be reduced or extended as follows: 1) For periods specified as less than two years, the period may be extended by up to 25% for any given test. 2) For periods specified as greater than or equal to 2 years, the period may be extended by up to 6 months for any given test. 3) All periods specified may be reduced at the discretion of the owner (i.e., there is no minimum period requirement).
Period extension is to facilitate test scheduling and considers plant operating conditions that may not be suitable for performance of the required testing (e.g., performance of the test would cause an unacceptable increase in the plant risk profile due to transient conditions or other ongoing surveillance, test or maintenance activities).
Period extensions are not intended to be used repeatedly merely as an operational convenience to extend test intervals beyond those specified. Period extensions may also be applied to accelerated test frequencies (e.g. pumps in Alert Range) and other less than two year test frequencies not specified in Table 1 (below). Period extensions may not be applied to the test frequency requirements specified in Subsection
/STD, Preservice and lnservice Examination and Testing of Dynamic Restraints (Snubbers) in Light-water Reactor Nuclear Power Plants, as Subsection
/STD contains its own rules for period extensions.
Table 1 Frequency Specified Time Period Between Tests Quarterly 92 days (or every 3 months) Semiannually 184 days (or every 6 months) Annually 366 days (or every year) X Years x calendar years, where "x" is a whole number of years ;:::: 2 (b) Components whose test frequencies are based on the occurrence of plant conditions or may not have their period between tests extended except as allowed by the ASME OM, Division 1, Section /ST, 2009 Edition through OMa-2011 Addenda and all earlier editions and addenda. Requiring the licensee to meet the ASME OM Code requirements and applicable adopted ASME OM Code Cases, without an allowance for defined frequency and frequency extensions for IST of pumps and valves, results in a hardship without a compensating increase in the level of quality and safety. Without the provision for applying operational flexibility to OM testing frequencies contained in ASME OM Code Case OMN-20, an unusual hardship is created for the plant to adequately facilitate test scheduling and possibly cause and unacceptable increase in the plant risk profile. Based on the prior acceptance by the NRC staff of the similar TS test interval definitions and interval extension criteria, the NRC staff concludes that implementation of the test interval definitions and interval extension criteria contained in ASME OM Code Case OMN-20, is therefore, acceptable.
Allowing usage of ASME Code Case OMN-20 provides reasonable assurance of operational readiness of pumps and valves subject to the ASME OM Code IST.
4.0 CONCLUSION
As set forth above, the NRC staff concludes that the proposed alternative CN-GRR-01 provides reasonable assurance that the affected components are operationally ready. The NRC staff also concludes that compliance with the frequencies as specified in the ASME OM Code would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety. Accordingly, the NRC staff concludes, as stated above, that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(2).
Therefore, the NRC staff authorizes the use of relief request CN-GRR-01 for the remainder of the fourth 10-year IST interval at CNS, Units 1 and 2 which is currently scheduled to end August 19, 2025. All other ASME OM Code requirements for which relief was not specifically requested and approved in the subject requests for relief remain applicable.
Principal Contributor:
MFarnan, NRR Date: April 26, 2017 T. Simril
SUBJECT:
CATAWBA NUCLEAR STATION, UNITS 1 AND 2 -REQUEST FOR RELIEF NO. CN-GRR-01, ALTERNATIVE TO THE ASME OM CODE, BY ADOPTION OF CODE CASE OMN-20, "INSERVICE TEST FREQUENCIES" FOR THE FOURTH 10-YEAR INSERVICE TESTING INTERVAL (CAC NOS. MF9595 AND MF9596) DATED APRIL 26, 2017 DISTRIBUTION:
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DORL/LPL2-1/BC DAiiey MMarkley 4/13/17 4/26/17 OFFICIAL RECORD COPY