ML20252A004
| ML20252A004 | |
| Person / Time | |
|---|---|
| Site: | North Anna  |
| Issue date: | 09/23/2020 |
| From: | Markley M Plant Licensing Branch II |
| To: | Stoddard D Southern Nuclear Operating Co |
| Miller G | |
| References | |
| EPID L-2020-LLR-0023 | |
| Download: ML20252A004 (23) | |
Text
September 23, 2020 Mr. Daniel G. Stoddard Senior Vice President and Chief Nuclear Officer Innsbrook Technical Center 5000 Dominion Boulevard Glen Allen, VA 23060-6711
SUBJECT:
NORTH ANNA POWER STATION, UNIT NO. 1 - RE: REQUEST FOR RELIEF REQUEST FIFTH 10-YEAR INSERVICE TESTING INTERVAL (EPID L-2020-LLR-0023)
Dear Mr. Stoddard:
By letter dated January 22, 2020 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML20028D492), Virginia Electric Power Company (VEPCO, Dominion Energy Virginia) requested relief from the requirements of the American Society of Mechanical Engineers (ASME) OM Code, 2004 Edition, to support the Fifth 10-Year Inservice Testing (IST)
Program for pumps and valves.
Specifically, pursuant to subparagraph (1) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, to Title 10, Energy, of the Code of Federal Regulations (10 CFR 50.55a(z)(1)), the licensee requested that the U. S. Nuclear Regulatory Commission (NRC) authorize Alternative Requests P-1 and V-1 on the basis that the proposed alternatives would provide an acceptable level of quality or safety.
Pursuant to subparagraph (2) in paragraph (z) in Part 50 to Title 10 of the Code of Federal Regulations (10 CFR 50.55a(z)(2)), the licensee requested that the NRC authorize Alternative Requests P-3 and P-6 on the basis that compliance with the ASME OM Code would result in hardship or unusual difficulty without compensating increase in level of quality or safety.
Pursuant to subparagraph (5)(iii) in paragraph (f), Preservice and inservice testing requirements, in Part 50 to 10 CFR 50.55a(f)(5)(iii)), the licensee requested that the NRC grant Relief Requests P-2, P-4, and P-5 on the basis that compliance with the ASME OM Code would be impractical for the North Anna Power Station, (NAPS) Units 1 and 2.
The NRC staff has reviewed the subject requests and concludes, as set forth in the enclosed safety evaluation, that VEPCO has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a. Therefore, the NRC staff authorizes the proposed alternatives and grants the relief requested for NAPS, Units 1 and 2, for the durations requested, as described in the enclosed Safety Evaluation.
D. Stoddard All other ASME Code,Section XI requirements for which relief was not specifically requested and approved remain applicable, including third-party review by the Authorized Nuclear Inservice Inspector.
If you have any questions, please contact the Project Manager, Ed Miller at 301-415-2481 or via e-mail at Ed.Miller@nrc.gov.
Sincerely, Digitally signed by Michael T. Michael T. Markley Date: 2020.09.23 Markley 09:07:23 -04'00' Michael T. Markley, Chief Plant Licensing Branch 2-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-338
Enclosure:
Safety Evaluation cc: Listserv
ML20252A004 *Via SE Input **Via E-mail OFFICE NRR/DORL/LPL2-1/PM NRR/DORL/LPL2-1/LA NRR/DEX/EMIB/BC NRR/DORL/LPL2-1/BC NAME GEMiller** KGoldstein** ABuford* MMarkley**
DATE 9/17/2020 09/09/2020 9/2/2020 9/23/2020 SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR FIFTH 10-YEAR IST INTERVAL VIRGINIA ELECTRIC POWER COMPANY NORTH ANNA POWER STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-338 AND 50-339
1.0 INTRODUCTION
By letter dated January 22, 2020 (Agencywide Documents and Access Management System (ADAMS) Accession Number ML20028D492), Dominion Energy Virginia (Dominion, the licensee) submitted requests to the U.S. Nuclear Regulatory Commission (NRC) for relief from or alternatives to certain Inservice Testing (IST) requirements in the American Society of Mechanical Engineers (ASME) Operation and Maintenance of Nuclear Power Plants, Division 1, OM Code: Section IST (OM Code), for the IST program at North Anna Power Station (NAPS) Units 1 and 2, during the Fifth 10-Year IST Program interval. In response to a request for additional information (RAI), the licensee provided supplemental information in its letter dated June 4, 2020 (ADAMS Accession Number ML20156A287). In its June 4, 2020, letter, the licensee withdrew Alternative Request S-1 as it was no longer needed with respect to snubber examination intervals.
Specifically, pursuant to subparagraph (1) in paragraph (z), Alternatives to codes and standards requirements, of Section 55a, Codes and standards, in Part 50, Domestic Licensing of Production and Utilization Facilities, to Title 10, Energy, of the Code of Federal Regulations (10 CFR 50.55a(z)(1)), the licensee requested that the NRC authorize Alternative Requests P-1 and V-1 on the basis that the proposed alternatives would provide an acceptable level of quality or safety.
Pursuant to subparagraph (2) in paragraph (z) in Part 50 to Title 10 of the Code of Federal Regulations (10 CFR 50.55a(z)(2)), the licensee requested that the NRC authorize Alternative Requests P-3 and P-6 on the basis that compliance with the ASME OM Code would result in hardship or unusual difficulty without compensating increase in level of quality or safety.
Pursuant to subparagraph (5)(iii) in paragraph (f), Preservice and inservice testing requirements, in Part 50 to Title 10 of the Code of Federal Regulations (10 CFR 50.55a(f)(5)(iii)), the licensee requested that the NRC grant Relief Requests P-2, P-4, and P-5 on the basis that compliance with the ASME OM Code would be impractical for the NAPS Units 1 and 2.
Enclosure
The NRC staff describes its review of the submitted alternative and relief requests for NAPS Units 1 and 2 in this safety evaluation (SE).
2.0 REGULATORY EVALUATION
The NRC regulations in 10 CFR 50.55a(f)(4), Inservice testing standards requirement for operating plants, state, in part, that throughout the service life of a boiling or pressurized water-cooled nuclear power facility, pumps and valves that are within the scope of the ASME OM Code must meet the inservice test requirements (except design and access provisions) set forth in the ASME OM Code and addenda that become effective subsequent to editions and addenda specified in 10 CFR 50.55a(f)(2) and (3) and that are incorporated by reference in 10 CFR 50.55a(a)(1)(iv), to the extent practical within the limitations of design, geometry, and materials of construction of the components.
The NRC regulations in 10 CFR 50.55a(z) state, in part, that alternatives to the requirements of 10 CFR 50.55a(f) may be used, when authorized by the NRC, if the licensee demonstrates (1) the proposed alternatives would provide an acceptable level of quality and safety or (2) compliance with the specified requirements would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.
The NRC regulations in 10 CFR 50.55a(f)(5)(iii) require that, if a licensee has determined that conformance with certain Code requirements is impractical for its facility, the licensee shall notify the Commission and submit information to support the determination.
The NRC regulations in 10 CFR 50.55a(f)(6)(i) state, in part, that the Commission will evaluate determinations, under paragraph 10 CFR 50.55a(f)(5), that Code requirements are impractical.
The Commission may grant such relief and may impose such alternative requirements as it determines are authorized by law, will not endanger life or property or the common defense and security, and are otherwise in the public interest, giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility.
The NAPS Units 1 and 2 Fifth 10-Year IST Program interval begins on December 15, 2020, and is scheduled to end on December 14, 2030. The applicable ASME OM Code edition for the NAPS Units 1 and 2 Fifth 10-Year IST Program interval is the 2012 Edition, which is incorporated by reference in 10 CFR 50.55a with conditions.
3.0 TECHNICAL EVALUATION
3.1 Licensees Alternative Request P-1 The licensee submitted Alternative Request P-1 related to the pump testing requirements in the ASME OM Code, Subsection ISTB, Inservice Testing of Pumps in Light-Water Reactor Nuclear Power Plants - Pre-2000 Plants, in accordance with 10 CFR 50.55a(z)(1).
Subparagraph (c) in paragraph ISTA-3130, Application of Code Cases, in ASME OM Code, Subsection ISTA, General Requirements, states, Code Cases shall be in effect at the time the test plan is filed except as provided in subpara. ISTA-3130(d).
Paragraph ISTB-3300, Reference Values, in ASME OM Code, Subsection ISTB, describes how reference values shall be obtained.
Subsection ISTB of the ASME OM Code, Table ISTB-5121-1, Centrifugal Pump Test Acceptance Criteria, specifies the acceptance criteria for Group A, Group B, and Comprehensive tests for centrifugal pumps.
Subsection ISTB of the ASME OM Code, Table ISTB-5221-1, Vertical Line Shaft Centrifugal Pump Test Acceptance Criteria, specifies the acceptance criteria for Group A, Group B, and Comprehensive tests for vertical line shaft centrifugal pumps.
The licensee requested the NRC staff to authorize the use of Alternative Request P-1 described below for all pumps in the IST program for NAPS Units 1 and 2 with vibration reference values 0.050 inches per second (in/sec).
Reason for Request
The licensee states:
Pumps in the ASME Inservice Testing program with very small vibration reference values (Vr) 0.050 in/sec are considered to be smooth running pumps.
Small values for Vr produce small acceptable ranges for pump operation. The acceptable ranges are defined in Tables ISTB-5121-1 and ISTB-5221-1 as 2.5Vr. Based on the small acceptable range, a smooth running pump could be subject to unnecessary corrective action if the measured vibration parameter exceeds this acceptable range.
For very small reference values, hydraulic noise and instrument error can be a significant portion of the reading and affect the repeatability of subsequent measurements.
Proposed Alternative The licensee is requesting authorization to implement ASME OM Code Case OMN-22, Smooth Running Pumps. This Code Case is not yet included in Regulatory Guide (RG) 1.192, Operation and Maintenance Code Case Acceptability, ASME OM Code.
The licensee states, in part, that:
In addition to the requirements of ISTB, the pumps in the ASME Inservice Testing Program are included in the North Anna Predictive Maintenance [PdM]
Program. This program currently employs predictive monitoring techniques such as:
vibration monitoring and analysis beyond that required by ISTB, spectral analysis of measured vibration data to provide early identification and diagnosis of pump performance issues, and oil sampling and analysis where applicable (e.g., for pumps with sufficiently large oil reservoirs).
If the measured paramenters [a PdM supplemental monitoring activity identifies a paramenter that] are outside the normal operating range or are determined by analysis to be trending toward an unacceptable degraded state, appropriate actions shall be taken that may include:
[Identify and document the condition in the corrective action program established in accordance with NAPS Units 1 and 2 quality assurance program,]
Increase monitoring to establish rate of change [of the monitored parameter],
Review component-specific information to identify [the degradation]
cause,
[Develop a plan to] remove the pump from service to perform maintenance [prior to significant performance degradation], and
[Address potential common cause issues applicable to other pumps based on the analysis of the specific pump performance].
The actions outlined above are in line with those prescribed in Code Case OMN-22. It should be noted that all of the pumps in the IST Program will remain in the Predictive Maintenance [PdM] Program even if certain pumps have very low vibration readings and are considered to be smooth running pumps.
Duration of the Alternative The proposed alternative described in Relief Request P-1 is for the NAPS Unit 1 and 2 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
The licensee proposes to apply ASME OM Code Case OMN-22 for all smooth running pumps in its IST program at NAPS. The Code Case has been approved by the ASME OM Standards Committee, with the NRC representative voting in the affirmative. The Code Case has also been approved by the ASME Board of Nuclear Codes and Standards.
Based on voting at the ASME OM Standards Committee, the NRC staff will include ASME Code Case OMN-22 in the Revision 4 of RG 1.192 as acceptable for use without conditions.
RG 1.192, Revision 4, is currently scheduled to be for incorporation by reference in 10 CFR 50.55a in a proposed rulemaking to be issued in the fall of 2020. ASME Code Case OMN-22 is applicable to the 2012 Edition of the ASME OM Code, which will be the licensees OM Code of Record for the Fifth 10-Year IST Program interval at NAPS.
The NRC staff has determined that the proposed alternative ASME OM Code Case OMN-22 is acceptable, therefore, the NRC staff finds that the use of Code Case OMN-22 provides an acceptable level of quality and safety in accordance with 10 CFR 50.55a(z)(1) for the pumps in the licensees IST program at NAPS.
3.2 Licensees Relief Request P-2 The licensee submitted Relief Request P-2 related to pump testing requirements in the ASME OM Code, Subsection ISTB, in accordance with 10 CFR 50.55a(f)(5)(iii), on the basis of impracticality.
Subsection ISTB of the ASME OM Code, paragraph ISTB-3400, Frequency of Inservice Tests, states, An inservice test shall be run on each pump as specified in Table ISTB-3400-1.
Subsection ISTB of the ASME OM Code, Table ISTB-3400-1, Inservice Test Frequency, requires a Group A test to be performed quarterly and a comprehensive test to be performed biennially.
The licensee requested the NRC staff to grant Relief Request P-2 described below for the pumps listed in Table 1 of this SE.
Table 1 Pump ASME ASME OM Pump Identification No. Description Code Class Group 1-RH-P-1A Residual Heat Removal 2 A (RHR) Pump 1-RH-P-1B RHR Pump 2 A 2-RH-P-1A RHR Pump 2 A 2-RH-P-2B RHR Pump 2 A
Reason for Request
The Residual Heat Removal (RHR) pumps, which have a design pressure of 600 pounds per square inch gauge (psig), take suction from and discharge to the reactor coolant system (RCS).
The RCS is maintained at 2235 psig during normal operation. Therefore, the RHR system could be damaged if it is exposed to the higher RCS pressure during normal operation. Per the licensees Technical Requirements Manual (TRM), the RHR system must be isolated from the RCS prior to the RCS exceeding 500 psig by closing and de-energizing both remote operated RHR suction isolation valves and locking the associated breakers open. Therefore, the licensee considers the testing of the RHR pumps during normal operation to be impractical.
Proposed Alternative The comprehensive pump test (CPT) for the RHR pumps will be performed every cold shutdown and reactor refueling outage, but not more frequently than once every three months. The quarterly Group A test will not be performed.
Duration of the Alternative The proposed alternative described in Relief Request P-2 is for the NAPS Unit 1 and 2 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
Subsection ISTB of the ASME OM Code, Table ISTB-3400-1, requires that a Group A test be performed quarterly on each Group A pump in the IST program. The RHR pumps are located inside containment (subatmospheric) and are low-pressure (600 psig design) pumps which take suction from the RCS, pass flow through the RHR heat exchangers, and discharge back to the RCS. The NAPS Unit 1 and 2 TRM specifies that the RHR system be isolated from the RCS before the RCS exceeds 500 psig by closing and de-energizing both remotely operated RHR
suction isolation valves and locking the associated breakers. Therefore, testing the RHR pumps during normal operation is inconsistent with RHR system design pressure and the TRM.
Therefore, the NRC staff finds that the quarterly Group A testing of the RHR pumps in accordance with the ASME Code is impractical. Major plant and system modifications would be required to allow quarterly testing of the RHR pumps according to the ASME OM Code. The licensee will perform a CPT for these RHR pumps during every cold shutdown and refueling outage, but not more frequently than once every three months. This is more frequent than the ASME OM Code-required frequency of biennially. Also, the CPT requires more precise pressure instruments (1/2 percent accuracy versus 2 percent accuracy) than the Group A test, and it also has a more precise acceptable range of operation.
Based on the above, the NRC staff finds that compliance with the ASME OM Code test frequency requirements for the RHR pumps listed in Table 1 of this SE is impractical. The licensee's Relief Request P-2 provides reasonable assurance that the RHR pumps are operationally ready.
3.3 Licensees Alternative Request P-3 The licensee submitted Alternative Request P-3 related to the pump testing requirements in the ASME OM Code, Subsection ISTB, in accordance with 10 CFR 50.55a(z)(2), on the basis of hardship.
Subsection ISTB of the ASME OM Code, Table ISTB-3000-1, Inservice Test Parameters, requires that pump flow rate be measured during a Group A test.
Subsection ISTB of the ASME OM Code, Table ISTB-3400-1, Inservice Test Frequency, requires a Group A test to be performed quarterly.
Paragraph ISTB-5121, Group A Test Procedure, in the ASME OM Code, Subsection ISTB, states, in part, Group A tests shall be conducted with the pump operating as close as practical to a specified reference point and within the variances from the reference point as described in this paragraph.
Subparagraph (b) in paragraph ISTB-5121 in the ASME OM Code Subsection ISTB, states, The resistance of the system shall be varied until the flow rate is as close as practical to the reference point with variance not to exceed +2% or -1% of the reference point. The differential pressure shall then be determined and compared to its reference value. Alternatively, the flow rate shall be varied until the differential pressure is as close as practical to the reference point with the variance not to exceed +1% or -2% of the reference point and the flow rate determined and compared to the reference flow rate.
The licensee requested the NRC to authorize Alternative Request P-3 described below for the pumps listed in Table 2 of this SE.
Table 2 Pump ASME ASME OM Unit Identification No. Description Code Class Pump Group 1-CH-P-2A Boric Acid Transfer Pump 2 A 1 1-CH-P-2B Boric Acid Transfer Pump 2 A 1 1-CH-P-2C Boric Acid Transfer Pump 2 A 2 1-CH-P-2D Boric Acid Transfer Pump 2 A 2
Reason for Request
Permanent flow instrumentation is not installed on the boric acid transfer pumps recirculation loop piping, which is the only test loop available for quarterly testing of these pumps. Flow must be established to the charging pump suction lines for the measurement activity. This flow would increase the RCS boron inventory and cause a reactivity transient during normal operation.
The pump test requires an extended period of boric acid injection that should only be performed when borating the reactor in preparation for refueling with low boron concentration. The test cannot be conducted during mid-cycle cold shutdown because the boron concentration in the RCS is too high. The potential for over boration under these conditions could delay the ability of the plant to restart, due to the time required to dilute the excess boron in preparation for startup.
Proposed Alternative The licensee states, in part, that:
These pumps will be tested quarterly using the recirculation loop, and differential pressure and vibration will be measured, evaluated, and trended. Every reactor refueling, a comprehensive test measuring differential pressure, flow rate and vibration will be performed.
The removal of quarterly flow testing of these pumps has been deemed acceptable per NRC Generic Letter (GL) 89-04 [Guidance on Developing Acceptable Inservice Testing Programs], Position 9, which allows elimination of minimum flow test line flow rate measurements providing inservice tests are performed during cold shutdowns or refueling periods under full or substantial flow conditions where pump flow rate is recorded and evaluated. The proposed alternate testing is consistent with this philosophy and the intent of Position 9.
Duration of the Alternative The proposed alternative described in Relief Request P-3 is for the NAPS Unit 1 and 2 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
Subsection ISTB of ASME OM Code, Table ISTB-3000-1, requires that the flow rate for a pump be measured during a Group A test, and also requires that a Group A test be run on each Group A pump quarterly.
The Group A pump test requires an extended period of boric acid injection and should only be performed when borating the reactor to cold shutdown conditions in preparation for refueling.
Conducting the test during a mid-cycle cold shutdown evaluation, when the initial boron concentration in the RCS can be significantly higher, might delay the plant restart until the excess boron is diluted.
The recirculation loop flow path is the only path available and will be used by the licensee to perform the quarterly Group A pump tests for the boric acid transfer pumps. However, the flow rate cannot be measured because there is no flow instrumentation in the recirculation loop piping. Compliance with the ASME OM Code requirements to measure flow would require system modifications and installation of online flow instrumentation. In lieu of the ASME OM Code-required test, the licensee proposes to test these pumps quarterly on the recirculation loops and measure the differential pressure and vibration. In addition, at every reactor refueling outage, the licensee will perform a CPT to measure differential pressure, flow, and vibration.
This alternative testing of the boric acid transfer pumps is consistent with NRC Generic Letter (GL) 89-04, Position 9.
Based on the above, the NRC staff finds that requiring the licensee to perform flow testing during the Group A pump tests for the boric acid transfer pumps listed in Table 2 of this SE, as required by the ASME OM Code, would result in a hardship, without a compensating increase in the level of quality and safety, due to the lack of permanent flow instrumentation in the recirculation piping required for quarterly pump testing. A CPT of the boric acid transfer pumps, measuring flow, differential pressure, and vibration will be performed every refueling outage.
The NRC staff finds that performing the CPT is adequate to demonstrate operational readiness of the pumps.
3.4 Licensees Relief Request P-4 The licensee submitted Relief Request P-4 related to the pump testing requirements in the ASME OM Code, Mandatory Appendix V, Pump Periodic Verification Test Program, in accordance with 10 CFR 50.55a(f)(5)(iii), on the basis of impracticality.
Mandatory Appendix V of the ASME OM Code, Pump Periodic Verification Test Program, Section V-3000, General Requirements, states, in part, The Owner shall (a) identify those certain applicable pumps with specific design basis accident flow rates in the Owners credited safety analysis (e.g., technical specifications, technical requirements program, or updated safety analysis report) for inclusion in this program.
The licensee requested the NRC staff to grant Relief Request P-4 described below for the pumps listed in Table 3 of this SE.
Table 3 Pump ASME ASME OM Identification No. Description Code Class Pump Group 1-RS-P-2A Outside Recirculation Spray Pump 2 B 1-RS-P-2B Outside Recirculation Spray Pump 2 B 2-RS-P-2A Outside Recirculation Spray Pump 2 B 2-RS-P-2B Outside Recirculation Spray Pump 2 B
Reason for Request
The licensee states, in part, that:
The test loop for the outside recirculation spray pumps consists of a 10-inch pump discharge line feeding into a 4-inch recirculation line which feeds back to the pump sump. The LOCA containment analysis assumes that the outside recirculation spray pumps deliver 3350 gpm. With the 4-inch recirculation line as the test loop, the design basis accident flow rate of 3350 gpm cannot be achieved. The highest flow rate that can be established while maintaining stable test conditions is approximately 1450 gpm in the test loop, which is approximately 43% of the pump safety analysis flow rate.
Flow cannot be established in the existing discharge piping because the flow would be directed to the spray headers inside containment, which would spray water throughout the containment. Also, the discharge piping was not designed to be temporarily reconfigured so that pump design flow could be achieved.
The outside recirculation spray pumps for Unit 2 were subject to long term full flow testing in 1979, during the construction phase. A test loop was established by replacing the spray nozzles from each of the two spray headers (150 nozzles for each header) with plugs, discharging pump flow to the spray headers and directing the flow back to the containment sump. A dike was constructed around the containment sump to simulate water levels in containment that are expected during an accident. The outside recirculation spray pumps took suction from the sump, thus, completing the loop. Re-establishing this full flow test loop for the purpose of periodic testing would require plant modifications and is not practicable.
The spray headers are inaccessible without a significant amount of scaffolding.
Even if the nozzles were accessible, the plugging of 300 spray nozzles, running the full flow test and returning the system to its operable configuration present substantial challenges in terms of complexity of the temporary modifications, labor intensive nature of the modifications, and controls and post modification testing needed to ensure that the system is returned to the original configuration.
Proposed Alternative The CPT performed on the recirculation test line will be credited for meeting the pump periodic verification test requirement in Mandatory Appendix V of the ASME OM Code for the pumps in Table 3 of the SE. The CPT flow rate will be established at 1350 gpm, which is 40 percent of the design basis accident flow rate.
The pump curve for these pumps have a relatively constant slope from no flow to design flow conditions. Testing at the CPT flow rate will detect pump degradation because the pump curve is well sloped at this point on the pump curve.
The pumps are included in the NAPS PdM program. This program includes:
Vibration monitoring and analysis beyond what is required by subsection ISTB of the ASME OM Code, Spectral analysis of measured vibration data to provide early identification and diagnosis of pump performance issues, and Oil sampling and analysis where applicable (e.g. for pumps with sufficiently large oil reservoirs).
Each CPT will be limited in duration to accommodate accurate performance data while minimizing fluid temperature rise and material wear. Following each test, the pump casing and associated test piping will be drained.
The only corrective maintenance that has been necessary for these pumps has been seal replacements. The IST activities for these pumps have not shown any degrading trends.
Duration of the Alternative The proposed alternative described in Relief Request P-4 is for the NAPS Unit 1 and 2 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
Mandatory Appendix V of the ASME OM Code requires that pumps with specific design basis accident flow rates in the licensees credited safety analysis be included in the pump periodic verification test program. If the pumps CPT or Group A flow rates do not bound the design basis accident flow rate, the pump periodic verification test must be performed to verify that the pump can meet the required (differential or discharge) pressure as applicable, at its highest design basis accident flow rate.
Due to the size of the test loop piping, the outside recirculation spray pumps cannot achieve the design basis accident flow rate of 3350 gpm. The highest flow rate that can be achieved in the test loop is 1450 gpm. In order to achieve a flow rate of 3350 gpm, the piping to the spray headers must be used as the flow path, which means that the spray nozzles must be plugged, and the water must be directed to the containment sump; a dike must be constructed around the sump; and a significant amount of scaffolding must be constructed in order to plug the spray nozzles. After the full flow pump periodic verification test, the temporary modifications must be removed, and post modification testing is required to ensure that the system is returned to its
original configuration. The NRC staff finds that these activities are significantly burdensome with very little safety benefit. Therefore, the NRC staff considers performance of a pump periodic verification test as specified in ASME OM Code, Mandatory Appendix V, for the outside recirculation spray pumps is impractical.
The licensee reported that the NAPS Unit 2 outside recirculation spray pumps were subject to long term full flow testing in 1979. The licensee stated that none of the pumps have shown degradation in their IST activities. The pump curve is well sloped from no flow to above the design basis accident flow rate, so operating the pump at the CPT flow rate will readily detect any degradation. The pumps are included in the NAPS PdM program, and receive predictive monitoring that exceeds the ASME OM Code requirements. The licensee stated that the only maintenance required for the pumps over the years has been seal replacement. Also, since these pumps are classified as Group B pumps, they are only operated during the quarterly Group B test and the biennial CPT.
Based on the above, the NRC staff finds that compliance with the ASME OM Code requirement for testing is impractical for the outside recirculation spray pumps listed in Table 3 of this SE.
The staff considers the proposed CPT alternative to provide reasonable assurance that the outside recirculation spray pumps are operationally ready.
3.5 Licensees Relief Request P-5 The licensee submitted Relief Request P-5 related to the pump testing requirements in the ASME OM Code, Mandatory Appendix V, in accordance with 10 CFR 50.55a(f)(5)(iii), on the basis of impracticality.
Mandatory Appendix V of the ASME OM Code, Section V-3000, states, in part, The Owner shall (a) identify those certain applicable pumps with specific design basis accident flow rates in the Owners credited safety analysis (e.g., technical specifications, technical requirements program, or updated safety analysis report) for inclusion in this program.
The licensee requested the NRC staff to grant Relief Request P-5 as described below for the pumps listed in Table 4 of this SE.
Table 4 Pump Identification No. ASME ASME OM Pump Description Code Class Group 1-QS-P-1A Quench Spray Pump 2 B 1-QS-P-1B Quench Spray Pump 2 B 2-QS-P-1A Quench Spray Pump 2 B 2-QS-P-1B Quench Spray Pump 2 B
Reason for Request
The licensee states, in part, that:
The test loop for the quench spray pumps consists of an 8-inch pump discharge line feeding into a 4-inch recirculation line that directs flow back to the refueling water storage tank. The 4-inch recirculation path includes a 4-inch globe valve which is fully open during performance of the Group B test and the Comprehensive test [CPT]. As such this loop is characterized as a fixed resistance loop.
Normal flow is directed from the 8-inch pump discharge line into containment and up to an 8-inch 360 degree spray header. Flow cannot be established in this flow path as it would be directed to the spray headers inside containment, which would spray water throughout the containment. Also, the discharge piping was not designed to be temporarily reconfigured so that pump design flow could be achieved. As such all pump performance testing must be performed using the installed test loop.
For preoperational testing, ends of the quench spray headers were fitted with blind flanges, allowing connection of temporary drain lines for full flow testing up to the nozzles. The recirculation spray nozzle connections were plugged for preoperational testing and temporary connections made between the spray headers and the containment sump, allowing full flow test of the system. These provisions permitted testing of the containment depressurization system over the full range of flow and starting conditions. Re-establishing this full flow test loop for the purpose of periodic testing would require extensive plant modifications and as such, is not practicable.
Minimum design basis accident flow requirements for 1-QS-P-1A and 2-QS-P-1A (A Header) are 1669.4 gpm, and for 1-QS-P-1B and 2-QS-P-1B (B Header) are 1719.6 gpm accounting for flow losses and uncertainties. Current comprehensive test [CPT] flow rates for these pumps when tested on the test loop are 1698.5 gpm, 1611.5 gpm, 1698.5 gpm and 1616.0 gpm respectively.
Only 1-QS-P-1A achieves the prescribed PPV flow rate when flow is directed through the test loop. Accounting for normal pump hydraulic performance degradation allowed by the ASME OM Code, this flow volume through the test loop may not be consistently achieved over time by this pump.
Proposed Alternative The CPT performed on the recirculation test line will be performed each refueling outage. The pump periodic verification test will not be performed. The licensee stated that for the quench spray pumps, the CPT flow rates have been established near to the analyzed design basis flow rates. Achieving required flow during the bounding design basis accident is assured by the discharge pressure associated with flowing through the 4-inch test line exceeding the required discharge pressure associated with flowing through the 8-inch discharge line into the containment building and out the quench spray header spray rings. This is evidenced by the CPT discharge pressure reference values for quench spray pumps 1-QS-P-1A, 2-QS-P-1A, 1-QS-P-1B and 2-QS-P-1B being 131.9 psig, 135.0 psig, 138.6 psig and 141.0 psig, respectively, to achieve near design basis flow rates through the 4-inch test loop, while the
maximum analyzed discharge pressure required to achieve design basis flow rates through the normal 8-inch flow path to the associated spray ring headers is 105.9 psig for the A header and 108.6 psig for the B header.
The quench spray pumps are included in the NAPS PdM program. This program includes:
Vibration monitoring and analysis beyond what is required by subsection ISTB of the ASME OM Code, Spectral analysis of measured vibration data to provide early identification and diagnosis of pump performance issues, and Oil sampling and analysis where applicable (e.g. for pumps with sufficiently large oil reservoirs).
Each CPT will be limited in duration to accommodate accurate performance data while minimizing fluid temperature rise and material wear.
The only corrective maintenance that has been necessary for these pumps has been seal replacements. The IST activities for these pumps have not shown any degrading trends.
Duration of the Alternative The proposed alternative described in Relief Request P-5 is for the NAPS Unit 1 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
Mandatory Appendix V of the ASME OM Code requires that pumps with specific design basis accident flow rates in the licensees credited safety analysis be included in the pump periodic verification test program. If the pumps CPT or Group A flow rates do not bound the design basis accident flow rate, the pump periodic verification test must be performed to verify that the pump can meet the required (differential or discharge) pressure as applicable, at its highest design basis accident flow rate.
The CPT flow rates for three of the four quench spray pumps are slightly lower than the design basis accident flow rates. The fourth pumps CPT flow rate is slightly higher than the design basis accident flow rate. However, the pump discharge pressures are higher when pumping through the 4-inch test loop because the pressure drop in the test loop is greater than the pressure drop in the 8-inch main piping. When the pumps are providing flow to the spray nozzles, the flow rate will increase because of the lower discharge pressure, and there is reasonable assurance that the design basis accident flow rates should be achieved.
In order to perform a pump periodic verification test for the pumps, the system would have to be configured as it was for preoperational testing, which is described above. The NRC staff finds that this configuration is impractical for the system. The NRC staff notes that these pumps are classified as Group B pumps, so they are only operated during the quarterly Group B test and the biennial CPT.
Based on the above, the NRC staff finds that compliance with the ASME OM Code requirement for testing is impractical for the quench spray pumps listed in Table 4 of this SE. The staff
considers the proposed CPT alternative to provide reasonable assurance that the quench spray pumps are operationally ready.
3.6 Licensees Alternative Request P-6 The licensee submitted Alternative Request P-6 related to the pump testing requirements in the ASME OM Code, Subsection ISTB, in accordance with 10 CFR 50.55a(z)(2), on the basis of hardship.
Subsection ISTB of the ASME OM Code, paragraph ISTB-6200, Corrective Action, subparagraph (a), Alert Range, states, If the measured test parameter values fall within the alert range of Table ISTB-5121-1, Table ISTB-5221-1, Table ISTB-5321-1, or Table ISTB-5321-2, as applicable, the frequency of testing specified in paragraph ISTB-3400 shall be doubled until the cause of the deviation is determined and the condition is corrected, or an analysis of the pump is performed in accordance with subparagraph ISTB-6200(c).
The licensee requested the NRC staff to authorize Alterative Request P-6 described below for the Unit 1 Chemical and Volume Control System (CVCS) 1A charging pump 1-CH-P-1A. The pump is an ASME Boiler and Pressure Vessel Code,Section III, Class 2 pump, and an ASME OM Code Group A pump.
Reason for Request
One of seven vibration points on CVCS 1A charging pump 1-CH-P-1A fell into the Alert Range during performance of the CPT during the fall 2019 Unit 1 refueling outage. Per ISTB-6200(a),
because the vibration measurement falls within the alert range, a CPT would be required to be performed every 9 months (test frequency doubled) until the cause of the deviation is determined and the condition is corrected, or an analysis of the pump is performed in accordance with subparagraph ISTB-6200(c), Analysis. Performance of the CPT to achieve the required reference flow rate cannot be accomplished during normal power operations. It can only be achieved with the reactor head removed from the reactor vessel, allowing flow to be directed into the reactor cavity.
Proposed Alternative The licensee is proposing to perform a quarterly Group A test instead of the CPT at the frequency of every nine months required by ISTB-6200(a). The Group A test can be performed with the plant operational, while the CPT can only be performed with the plant in Mode 6 (Refueling). The licensee stated that this alternative will only apply to ISTB-6200 as it relates to doubling of the CPT test frequency. With subsequent Group A testing, if any measured IST parameter exceeds the alert criteria, the Group A test will be performed at the double test frequency in accordance with ISTB-6200(a).
Duration of the Alternative The proposed alternative described in Relief Request P-6 is from the beginning of the NAPS Unit 1 Fifth 10-Year Inservice Testing Interval to the N1R28 refueling, spring of 2021, and when plant conditions allow for the next CPT surveillance.
NRC Staff Evaluation
Subparagraph (a) in paragraph ISTB-6200 of the ASME OM Code, Subsection ISTB, specifies the testing frequency in paragraph ISTB-3400 shall be doubled for pumps whose measured test parameter values fall within the alert range of the applicable table (Table ISTB-5121-1, in this case).
The purpose of this increased CPT testing frequency for pumps in the alert range is to monitor for additional performance degradation until the cause of the deviation is determined, and the condition is corrected, or an analysis of the pump is performed in accordance with subparagraph ISTB-6200(c). The performance of pump 1-CH-P-1A can be tracked and trended by testing performed at flow rates other than those specified for the CPT. The reference point value for flow rate for the CPT is established in accordance with paragraph ISTB-3000, General Testing Requirements, at the CPT flow rate, and at the highest practicable flow rate for the Group A test if the CPT flow rate cannot be achieved. The highest practical Group A test reference point flow rate is 162 gallons per minute (gpm), as addressed in NRC-authorized Request P-8, which is no longer needed for the Fifth 10-Year IST Program interval (see ADAMS Accession No. ML102460223). The CPT reference point flow rate is 634 gpm.
Seven vibration monitoring points have been established in accordance with Subsection ISTB of the ASME OM Code. The pump vibration reference values do not differ significantly when comparing the Group A and CPT values as shown in Table P-6.1 of the licensees submittal.
The vibration point that is in the alert range, Thrust Bearing Vertical, reflects a small difference of 0.0130 inches per second (ips) when comparing test reference values. As such, the Group A test provides a method to monitor pump vibration parameters comparable to that of the CPT without the need to shut down the plant.
The licensee outlined the maintenance and diagnostic history of pump 1-CH-P-1A dating back to a rebuild in August 2012. The licensee contracted with subject matter experts and a pump vendor for their recommendations on the vibration conditions. The licensee stated that there was no evidence of natural frequency, coupling misalignment, cocked bearings, or bowed rotor involvement in the elevated vibration conditions. The licensee established new baseline vibration reference values for the Group A test subsequent to an inspection and minor adjustment of the pump gearbox high-speed shaft and pump shaft coupling. The licensee reported that the vibration levels observed during the performance of the Group A test on July 13, 2017, remained relatively unchanged. During the CPT on September 22, 2019, measured vibrations at the thrust bearing vertical axis were 0.357 ips, which exceeds the ASME OM Code prescribed alert range absolute criteria of 0.325 ips, which was the first instance of such an exceedance during the CPT following maintenance in 2012.
The licensee stated that vibration data appear to be correlated between the CPT and Group A test, and the vibrations have been reasonably consistent, albeit elevated, since 2012. Using the more detailed plots of the vibration data in Figures P-6.1 and P-6.2 in the licensees submittal, the NRC staff was able to confirm that the vibration data are correlated between the CPT and Group A Test.
The licensee also provided additional information in its submittal supporting the capability of pump 1-CH-P-1A to perform its safety function:
Oil samples from the pump bearing reservoir do not present evidence of degradation (such as no wear particles, unacceptable viscosity, or change in additive content) since the initial increase of elevated vibrations in 2012.
Hydraulic performance data recorded during the September 22, 2019, CPT remains aligned with the operating curve with no notable decrease in flow or discharge pressure.
The maximum analyzed design basis accident required flow is 594.4 gpm at 2961.2 feet Total Developed Head (ft TDH). Since 2012, total run time for this pump has been 2800 hours0.0324 days <br />0.778 hours <br />0.00463 weeks <br />0.00107 months <br /> to 3900 hours0.0451 days <br />1.083 hours <br />0.00645 weeks <br />0.00148 months <br /> each year, and although vibrations have remained elevated, the pump hydraulic parameters do not show evidence of degrading performance.
Although the pump vibrations are elevated, the NRC staff finds that there is reasonable assurance that pump 1-CH-P-1A will continue to meet its safety function and flow requirements with the thrust bearing vertical vibration measurement in the alert range, based on the absence of degrading pump performance, as discussed above.
The NRC staff finds that the licensees request to perform quarterly Group A tests of pump 1-CH-P-1A in lieu of the CPT, which would cause a burden without a compensating increase in quality or safety, is reasonable because (1) the vibration data are correlated between the CPT and Group A test, (2) the licensee will monitor pump vibrations through the performance of the Group A test, and (3) the pump hydraulic parameters have not indicated any significant degradation in the hydraulic performance of the pump. The NRC staff finds the licensees proposed alternative provides reasonable assurance of the operational readiness of CVCS 1A charging pump 1-CH-P-1A.
3.7 Licensees Alternative Request V-1 The licensee submitted Alternative Request V-1 related to the valve testing requirements in the ASME OM Code, Mandatory Appendix I, Inservice Testing of Pressure Relief Devices in Light-Water Reactor Nuclear Power Plants, in accordance with 10 CFR 50.55a(z)(1).
Mandatory Appendix I of the ASME OM Code, paragraph I-8120, Compressible Fluid Services Other Than Steam, subparagraph (h), Time Between Valve Openings, states, A minimum of 5 min shall elapse between successive openings.
Mandatory Appendix I, of the ASME OM Code, paragraph I-8130, Liquid Service, subparagraph (g), Time between Valve Openings, states, A minimum of 5 min shall elapse between successive openings.
The licensee requested the NRC staff to authorize Alternative Request V-1 as described below for the Unit 1 and Unit 2 safety and relief valves, excluding main steam safety valves (MSSVs),
listed in Table 5 of this SE.
Table 5 Unit 1 Valve Unit 2 Valve System ASME Class Test Medium Number Number 1-CC-RV-124A 2-CC-RV-224A Component 3 Water Cooling 1-CC-RV-124B 2-CC-RV-224B Component 3 Water Cooling 1-CC-RV-124C 2-CC-RV-224C Component 3 Water Cooling 1-CC-RV-125A 2-CC-RV-225A Component 3 Water Cooling 1-CC-RV-125B 2-CC-RV-225B Component 3 Water Cooling 1-CC-RV-125C 2-CC-RV-225C Component 3 Water Cooling 1-CC-RV-126 2-CC-RV-226 Component 3 Water Cooling 1-CC-RV-128A 2-CC-RV-228A Component 3 Water Cooling 1-CC-RV-128B 2-CC-RV-228B Component 3 Water Cooling 1-CC-RV-131A 2-CC-RV-231A Component 3 Water Cooling 1-CC-RV-131B 2-CC-RV-231B Component 3 Water Cooling 1-CH-RV-1203 2-CH-RV-2203 Chemical and 2 Water Volume Control 1-CH-RV-1382A 2-CH-RV-2382A Chemical and 2 Water Volume Control 1-CH-RV-1382B 2-CH-RV-2382B Chemical and 2 Water Volume Control 1-FW-RV-100 2-FW-RV-200 Auxiliary 3 Water Feedwater 1-HV-RV-1200 2-HV-RV-2200 Control Room 3 Water Chilled Water 1-HV-RV-1201 2-HV-RV-2201 Control Room 3 Water Chilled Water 1-HV-RV-1202A 2-HV-RV-2202A Control Room 3 Water Chilled Water 1-HV-RV-1202B 2-HV-RV-2202B Control Room 3 Water Chilled Water 1-HV-RV-1202C 2-HV-RV-2202C Control Room 3 Water Chilled Water 1-HV-RV-1205A 2-HV-RV-2205A Control Room 3 Water Condenser Water 1-HV-RV-1205B 2-HV-RV-2205B Control Room 3 Water Condenser Water
Unit 1 Valve Unit 2 Valve System ASME Class Test Medium Number Number 1-HV-RV-1205C 2-HV-RV-2205C Control Room 3 Water Condenser Water 1-RH-RV1721A 2-RH-RV-2721A Residual Heat 2 Water Removal 1-RH-RV-1721B 2-RH-RV-2721B Residual Heat 2 Water Removal 1-SI-RV-1845A 2-SI-RV-2845A Safety Injection 2 Water 1-SI-RV-1845B 2-SI-RV-2845B Safety Injection 2 Water 1-SI-RV-1845C 2-SI-RV-2845C Safety Injection 2 Water 1-SI-RV-1847 2-SI-RV-2847 Safety Injection 2 Water 1-SI-RV-1858A 2-SI-RV-2858A Safety Injection 2 Nitrogen 1-SI-RV-1858B 2-SI-RV-2858B Safety Injection 2 Nitrogen 1-SI-RV-1858C 2-SI-RV-2858C Safety Injection 2 Nitrogen 1-SW-RV-100A 2-SW-RV-200A Service Water 2 Water 1-SW-RV-100B 2-SW-RV-200B Service Water 2 Water 1-SW-RV-100C 2-SW-RV-200C Service Water 2 Water 1-SW-RV-100D 2-SW-RV-200D Service Water 2 Water 1-SW-RV-101A 2-SW-RV-201A Service Water 2 Water 1-SW-RV-101B 2-SW-RV-201B Service Water 2 Water
Reason for Request
Subparagraphs I-8120(h) and I-8130(g) in Mandatory Appendix I of the ASME OM Code require a minimum of two consecutive valve actuations to establish the lift setpoint of safety and relief valves and that a minimum of five minutes elapse between successive tests. For the safety and relief valves listed in Table 5, the requirement for verifying temperature stability by waiting 5 minutes between successive lift setpoint tests adds no value because the lift setpoint testing is conducted using water or nitrogen as the test medium, and the tests are performed when the valve and the test medium are at the same temperature. This results in a negligible effect on lift setpoint due to minor temperature deviations that might occur during testing. Eliminating the 5-minute wait time will minimize system outage times and radiation exposure.
Proposed Alternative The safety and relief valves listed in Table 5 of this SE are tested using test medium at ambient conditions, and the 5-minute hold requirement between successive openings will be deleted.
The licensee stated that in accordance with subparagraphs I-8120(a), and I-8130(a), the test medium used will be the same as the normal system operating fluid and temperature for which the valves in Table 5 were designed. For liquid service, this will be water. For compressible fluid services other than steam, this will be nitrogen. In both cases, the test stand and surrounding environment ambient temperature conditions are relatively fixed with negligible changes occurring over the set pressure and seat tightness test determinations. There is a negligible effect on valve setpoint due to minor temperature deviations that might occur at these conditions.
Duration of the Alternative The proposed alternative described in Relief Request P-1 is for the NAPS Unit 1 and 2 Fifth 10-Year Inservice Testing Interval.
NRC Staff Evaluation
The NRC staff notes that the 5-minute wait time requirement is based on the assumption that the temperature of the test medium is different than the temperature of the valve. Lift setpoint testing with different valve and test medium temperatures would cause the temperature of the valve to change once the valve opens; therefore, the setpoint could be affected. However, when the test medium and valve temperatures are the same during safety and relief valve testing, the thermal stabilization allows for the elimination of the wait period between tests, without affecting the setpoints of the valves. The licensee stated that many of the Class 2 and 3 safety and relief valves are bench-tested in a test shop located in the Auxiliary Building.
The licensee stated that those lift setpoint tests are performed conditions using a test medium of water or nitrogen at ambient conditions. As a result, there is no thermal differential between the valves and the test medium that might affect the test results. Thus, the NRC staff finds that elimination of the 5-minute wait period between lift setpoint tests, for the ASME Class 2 and 3 safety and relief valves listed in Table 5 of this SE, does not adversely impact the method of accurately and repeatedly determining setpoints when using water or nitrogen as the test medium. Therefore, the NRC staff finds that the licensee's proposed testing provides an acceptable alternative to the 5-minute wait period requirement in Mandatory Appendix I, subparagraphs I-8120(h), and I-8130(g), and provides an acceptable level of quality and safety for testing of the safety and relief valves listed in Table 5 of this SE.
4.0 CONCLUSION
As set forth above, the NRC staff has determined that Alternatives Requests P-1 and V-1 provide an acceptable level of quality and safety for all pumps in the IST program for NAPS Units 1 and 2 with vibration reference values 0.050 in/sec for Alternative Request P-1 and for all valves listed in Table 5 of this SE for Alternative Request V-1. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(z)(1) for Alternative Requests P-1 and V-1. Therefore, the NRC staff authorizes Alternative Requests P-1 and V-1 for the Fifth 10-Year IST Program interval at NAPS Units 1 and 2, which begins on December 15, 2020, and is currently scheduled to end on December 14, 2030.
As set forth above, the NRC staff has determined that Alternative Requests P-3 and P-6 provide reasonable assurance that the pumps listed in Table 2 of this SE and Unit 1 CVCS 1A charging pump 1-CH-P-1A, respectively, 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(z)(2) for Alternative Requests P-3 and P-6. Therefore, the NRC staff authorizes Alternative Request P-3 for the Fifth 10-Year IST Program interval, which starts on December15, 2020, and is scheduled to end on December 14, 2030. Also, the NRC staff authorizes Alternative Request P-6 from the beginning of the Fifth 10-Year IST Program interval, which begins on December 15, 2020, to the refueling outage in the spring of 2021, when plant conditions allow for the next CPT.
As set forth above, the NRC staff has determined that it is impractical for the licensee to comply with certain pump testing requirements of the ASME OM Code. The NRC staff has further determined that granting Relief Requests P-2, P-4, and P-5 for the pumps listed in Tables 1, 3, and 4 of this SE, respectively, in accordance with 10 CFR 50.55a(f)(6)(i), is authorized by law and will not endanger life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Accordingly, the NRC staff concludes that the licensee has adequately addressed all of the regulatory requirements set forth in 10 CFR 50.55a(f)(5)(iii), and is in compliance with the requirements of 10 CFR 50.55a with the granting of these relief requests. Therefore, the NRC staff grants relief, pursuant to 10 CFR 50.55a(f)(6)(i), for the testing alternatives contained in Relief Requests P-2, P-4, and P-5, for NAPS Units 1 and 2 for the Fifth 10-Year IST Program interval, which begins on December 15, 2020, and is scheduled to end on December 14, 2030.
All other ASME OM Code requirements for which relief or an alternative was not specifically requested and approved as part of these requests remain applicable.
Principal Contributor: R. Wolfgang, NRR Date: September 23, 2020