NOC-AE-20003703, Proposed Alternatives to ASME OM Code 2012 Edition for the Fourth Inservice Test Interval (Relief Request PRR-04)

Proposed Alternatives to ASME OM Code 2012 Edition for the Fourth Inservice Test Interval (Relief Request PRR-04)

ML20022A321
Person / Time
Site:	South Texas
Issue date:	01/22/2020
From:	Dunn R South Texas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NOC-AE-20003703
Download: ML20022A321 (5)

Text

Nuclear Operating Company South Texas Project Electric Generating Station P.O. Box 289 Wadsworth, Texas 77483 January 22,2020 NOC-AE-20003703 10CFR50.55a(z)

STI:34969739 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Proposed Alternatives to ASME OM Code 2012 Edition for the Fourth Inservice Test Interval (Relief Request PRR-04)

Pursuant to 10 CFR 50.55a(z), STP Nuclear Operating Company (STPNOC) hereby requests an alternative to the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) 2012 Edition for use during the fourth ten-year Inservice Test (1ST) interval at South Texas Project. The details of the request are attached.

STPNOC requests approval of the alternatives by September 1, 2020 to support the fourth ten-year interval starting on September 25,2020.

There are no new commitments in this letter.

If there are any questions regarding this request, please contact N. Boehmisch at 361-972-8172 or me at 361-972-7743.

l^oCM<X2^S>'t<'l 85

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-^r Roland Dunn General Manager, Engineering

Attachment:

Relief Request PRR-04, Use of Code Case OMN-22 ec:

Regional Administrator, Region IV U.S. Nuclear Regulatory Commission 1600 East Lamar Boulevard Arlington, TX 76011-4511

Attachment NOC-AE-20003703 Page 1 of 4 Attachment Relief Request PRR-04, Use of Code Case OMN-22

1. ASME Code Component(s) Affected All pumps in the 1ST Program with vibration reference (Vr) values of < 0.05 inches per second (ips). See Table 1 for the initial list of these pumps. The 0.05 ips value will be applied to individual vibration locations for listed pumps whose measured reference value is less than 0.05 ips. When new reference values are established, the measured parameters would be evaluated for each location to determine if the minimum value for Vr would apply.

The Table 1 pumps are required to perform a specific function in shutting down the reactor to a safe shutdown condition, maintaining a safe shutdown condition or mitigating the consequences of an accident.

2. Applicable Code Edition and Addenda

American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code) 2012 Edition.

3. Applicable Code Requirement

ISTB-3300(a), "Reference Values". Initial reference values shall be determined from the results of testing meeting the requirements to ISTB-3100, "Preservice Testing", or from the results of the first 1ST.

Table ISTB-5121-1, "Centrifugal Pump Test Acceptance Criteria", Alert Range and Required Action Range.

Table ISTB-5221-1, "Vertical Line Shaft Centrifugal Pump Test Acceptance Criteria", Alert Range and Required Action Range.

Table ISTB-5321-1, "Positive Displacement Pump (Except Reciprocating) Test Acceptance Criteria", Alert Range and Required Action Range.

Table ISTB-5321-2, "Reciprocating Positive Displacement Pump Test Acceptance Criteria", Alert Range and Required Action Range.

4. Reason for Request

TheASME Code committees have approved Code Case OMN-22, "Smooth Running Pumps" and is scheduled to be published with the 2020 Edition of the OM Code. This Code Case has not been approved for use in Regulatory Guide 1.192.

Code Case OMN-22 allows for alternative requirements for use with smooth running pumps in lieu of use of vibration values obtained in the reference value tests. For very low reference values, hydraulic noise and instrument accuracy can represent a significant portion of the reading and affect the repeatability of subsequent measurements. A smooth running pump could be subject to unnecessary increased testing if the measured vibration parameter exceeds an acceptable range based on these very low reference values.

Attachment NOC-AE-20003703 Page 2 of 4 Smooth running pumps have a much lower reference value for stable operation and the ranges for acceptable range and higher levels listed in the Alert Range do not allow for adequate vibration monitoring techniques to be applied to smooth running pumps. Guidelines set forth in Code Case OMN-22 allow for a very low baseline vibration value with a pump vibration velocity of ^ 0.050 in/sec when establishing the vibration reference value, which allows for trending of the pump vibration on a much lower scale than what is currently allowed.

ASME OM Code Case OMN-22, "Smooth Running Pumps" has not been approved by the NRC and a relief request is required for use of this Code Case.

5. Proposed Alternative and Basis for Use STPNOC proposes to utilize the provisions of Code Case OMN-22, "Smooth Running Pumps".

For those pumps with very low vibration values, the following vibration velocity criteria shall be applied to any vibration test points qualifying for the use of the "minimum reference" value:

Acceptable Range: ^0.125 in/sec Alert Range: > 0.125 in/sec to 0.300 in/sec Required Action Range: > 0.300 in/sec Supplemental Monitorincj:

Pumps that will use the "minimum reference" value for one or more vibration points will be maintained in STPNOC's Predictive Maintenance (PdM) program. The PdM program will apply predictive monitoring techniques and perform vibration analysis beyond the trending of vibration levels specified in the ASME OM Code to provide early identification of pump performance issues.

At a minimum, STPNOC will perform spectral analysis of measured vibration of the applicable pumps. STPNOC will document the conclusion of the PdM performance analysis on the pump test record prior to the subsequent test with a conclusion of acceptable, degrading but acceptable, or unacceptable. Corrective action will be initiated when an unacceptable trend in performance is identified.

Corrective Action:

If a measured pump vibration parameter falls within the alert range or the required action range specified above, STPNOC will follow the required actions within the edition/addenda of the applicable Code (for example, ISTB-6200 for the 2012 Edition of the ASME OM Code). The alert and required action ranges would be established in accordance with Code Case OMN-22 rather than the requirements of ISTB-3300, ISTB-5100, ISTB-5200 and the associated tables.

If a PdM Supplemental Monitoring activity identifies a parameter outside the normal operating range or identifies a trend toward an unacceptable degraded state, action will be taken to (1) identify and document the condition in the Corrective Action Program, (2) increase monitoring to establish the rate of change of the monitored parameter, (3) review component-specific information to identify the degradation cause, (4) develop a plan to remove the pump from service to perform maintenance prior to significant performance degradation, and (5) address potential common cause issues applicable to other pumps based on the results of the analysis of the specific pump performance.

Using the provisions of this relief request as an alternative to the requirements of ISTB-3300 provides a reasonable alternative to the ASME OM Code requirements. Based on this determination, the proposed alternative provides an acceptable level of quality and safety.

Attachment NOC-AE-20003703 Page 3 of 4 Conclusion; In summary, STPNOC proposes to test the pumps listed in Table 1 of this request by implementing the requirements ofASME OM Code Case OMN-22 and requests NRC approval to implement this change because Code Case OMN-22 is not listed in Regulatory Guide 1.192.

Using the provisions of this request would provide adequate detection of component degradation and would continue to provide reasonable assurance of the operational readiness of affected components. Therefore, compliance with the requirements ofASME OM Code Case OMN-22 would result in an acceptable level of quality and safety pursuant to 10 CFR 50.55a(z)(1).

6. Duration of Proposed Alternative The proposed alternative, if approved, would be implemented from the end of the Third Interval (September 25, 2020) until the end of the Fourth Interval (September 25, 2030).

7. Precedent NRC approval of Millstone Power Station Units 2 and 3 relief requests P-02 and P-03 for smooth running pumps with measured reference values below 0.05 ips (Reference 2).

NRC approval of James A. Fitzpatrick Nuclear Power Plant relief request PRR-02 for smooth running pumps with measured reference values below 0.05 ips (Reference 3).

8. Reference

1. ASME OM Code-2012, Code Case OMN-22, "Smooth Running Pumps"

2. Letter from J.G. Danna, NRC, to D.G. Stoddard, Dominion Energy, "Millstone Power Station, Unit Nos. 2 and 3 - Alternative Requests Related to the Fifth and Fourth 10-year Interval Pump, Valve, and Snubber Inservice Testing Programs, Respectively (EPID L-2018-LLR-0012-Through EPiD L-2018-LLR-0022)", November 13, 2018, ML18290A602

3. Letter from J.G. Danna, NRC, to B.C. Hanson, Exelon Generation Company, "James A.

Fitzpatrick Nuclear Power Plant - Issuance of Relief Requests for Alternatives to Certain ASME OM Code Requirements", April 13, 2018, ML18044A993

Attachment NOC-AE-20003703 Page 4 of 4 Table 1: Initial Scope of PRR-04*

Pump Description TPNS Unit ASME Class Centrifugal Charging Pump 1A 2R171NPA101A 1 2 Centrifugal Charging Pump 1B 2R171NPA101B 1 2 Centrifugal Charging Pump 2A 2R172NPA201A 2 2 Essential Chilled Water Pump 1 1A 3V111VPA004 1 3 Essential Chilled Water Pump 1 1 B 3V111VPA005 1 3 Essential Chilled Water Pump 11C 3V111VPA006 1 3 Essential Chilled Water Pump 21A 3V112VPA004 2 3 Essential Chilled Water Pump 21 B 3V112VPA005 2 3 Essential Chilled Water Pump 21 C 3V112VPA006 2 3 Essential Cooling Water Pump 1A 3R281NPA101A 1 3 Essential Cooling Water Pump 1B 3R281NPA101B 1 3 Essential Cooling Water Pump 1C 3R281NPA101C 1 3 Essential Cooling Water Pump 2A 3R282NPA201A 2 3 Essential Cooling Water Pump 2B 3R282NPA201B 2 3 Essential Cooling Water Pump 2C 3R282NPA201C 2 3 Low Head Safety Injection Pump 1A 2N121NPA102A 1 2 Low Head Safety Injection Pump 1B 2N121NPA102B 1 2 Low Head Safety Injection Pump 1C 2N121NPA102C 1 2 Low Head Safety Injection Pump 2A 2N122NPA202A 2 2 Low Head Safety Injection Pump 2B 2N122NPA202B 2 2 Low Head Safety Injection Pump 2C 2N122NPA202C 2 2 Motor Driven Aux Feedwater Pump No. 11 3S141MPA01 1 3 Motor Driven Aux Feedwater Pump No. 22 3S142MPA02 2 3 Motor Driven Aux Feedwater Pump No. 23 3S142MPA03 2 3 Turbine Driven Aux Feedwater Pump No. 14 3S141MPA04 1 3 Residual Heat Removal Pump 1A 2R161NPA101A 1 2 Residual Heat Removal Pump 1B 2R161NPA101B 1 2 Residual Heat Removal Pump 1C 2R161NPA101C 1 2 Residual Heat Removal Pump 2A 2R162NPA201A 2 2 Residual Heat Removal Pump 2B 2R162NPA201B 2 2 Residual Heat Removal Pump 2C 2R162NPA201C 2 2 Spent Fuel Cooling Pump 1A 3R211NPA101A 1 3 Spent Fuel Cooling Pump 1B 3R211NPA101B 1 3 Spent Fuel Cooling Pump 2A 3R212NPA201A 2 3 Spent Fuel Cooling Pump 2B 3R212NPA201B 2 3

• Scope may change based on future reference values tests. When new reference values are established, the measured parameters would be evaluated for each location to determine if the minimum value for Vr would apply.