PLA-6657, 10 CFR 50.59 Summary Report and Changes to Regulatory Commitments

10 CFR 50.59 Summary Report and Changes to Regulatory Commitments

ML102800589
Person / Time
Site:	Susquehanna
Issue date:	10/07/2010
From:	Rausch T Susquehanna
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
PLA-6657
Download: ML102800589 (6)

Text

Timothy S. Rausch PPL Susquehanna, LLC Sf. Vice President & Chfef Nuclear Officer 769 Salem Boulevard k ' 1 Bew~ck,PA 18603 Tel. 570.542.3445 Fax 570.542.1504 tsrausch@pplweb.com QET O '7 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Mail Stop 0-P1- 17 Washington, DC 20555-000 1 SUSQUEHANNA STEAM ELECTRIC STATION 10 CFR 50.59

SUMMARY

REPORT AND Docket No. 50-387 CHANGES TO FWGULATORY COMMITMENTS and 50-388

Reference:

I) PU-6437, B. 7: McKinney (PPL) to Document Control Desk (USNRC),

" I0 CFR 50.59 Summary Report and Changes to Regulatory Commitments,"

dated October 9, 2008. is the summary report of the PPL Susquehanna, LLC 10 CFR 50.59 Evaluation of Changes, Tests, and Experiments approved during the period between September 1,2008 and August 3 1,2010. This report is required by 10 CFR 50.59(d)(2) and is to be submitted at intervals not to exceed 24 months. The previous report (Reference 1) included the period from September 1,2006 to August 3 1,2008.

The summary of the 50.59 Evaluation documented in Attachment 1 is formatted as follows:

50.59 Evaluation No: Unique number for each evaluation.

Cross-

Reference:

Reference to the document for which the 50.59 Evaluation was prepared.

Description of Change: A brief description of the changes, tests, and experiments.

Summary: A summary of PPL Susquehanna, LLC's basis for concluding that a license amendment was not required pursuant to 10 CFR 50.59(b)(2).

No Regulatory Commitments were changed in accordance with the guidance of NEI 99-04, "Guidelines for Managing NRC Commitment Changes," and SECY-00-045 for the period from September 1, 2008 to August 3 1,2010.

Document Control Desk PLA-6657 If you have any questions regarding this information, please contact Brenda O'Rourke at (570) 542- 1791.

Sincerely, : 10 CFR 50.59 Summary of Changes, Tests, and Experiments Copy:

NRC Region I Mr. P. A. Finney, NRC Sr. Resident Inspector Mr. R. R. Janati, DEP/BRP Mr. B. K. Vaidya, NRC Project Manager

Attachment 1 to PLA-6657 10 CFR 50.59 Summary of Changes, Tests, and Experiments

Attachment 1 to PLA-6657 Page 1 of 3 50.59 Evaluation No.: 50.59 SE 00013 Cross-

Reference:

LDCN Nos. 4679,4700,470 1,4708,4709,4710 Description of Change:

The modification removed existing analog, and in some cases obsolete, components and installed the Invensys Intelligent Automation (IIA) digital control system (referred to as the Integrated Control System (ICS)) in the Reactor Feedwater Pump Turbines (RFPT)

Speed Control, Reactor Vessel Water Level Control (Feedwater Level Control, FWLC),

and Reactor Recirculation PumpIM-G Sets Speed Control (RRP Speed Control) systems.

This Integrated Control System (ICS) consists of an Invensys Process Systems (IPS)

Intelligent/Automation (IIA) digital control system for process variable measurement, signal validation, process alarming, process control, and trip initiation. Integration of the IIA equipment with the field also requires the use of third party equipment such as servo positioning controllers, and associated power supplies. RFPT Over-speed protection is provided via third party electronics interfaced with the ICS. Input from existing analogldigital parameter measuring devices is maintained and new instrumentation installed to support the design requirements.

The new RRP Speed Control scheme is intended to enhance the control room operator's abilities to maintain maximum electrical generation without adding operator burden.

Operation at Extended Power Uprate conditions will often resuIt in the unit operating in a generator-limited condition, which would require the operator to make multiple manual reactor recirculation speed demand changes as secondary plant and electrical grid changes occur throughout the day. The need to accommodate this operation without increased burden, coupled with the interaction of affected systems and the ability to make small; incremental changes to controller outputs, established the necessity to install an integrated control process control system.

This 50.59 evaluation concluded that prior NRG approval of the changes described above was not required. Implementation of the changes did not require a change to the Technical Specifications or create the possibility of a new or different accident or malfunction previously evaluated in the Final Safety Analysis Report (FSAR).

The changes did not result in more than a minimal increase in frequency of occurrence of an accident. The changes did not increase the frequency of a SSC malfunction resulting in an accident as compared to the existing SSCs, nor will they increase the need for operator intenrention or operator burden to support operation of the system during normal

Attachment 1 to PLA-6657 Page 2 of 3 and off-normal conditions. The new ICS components will not adversely affect nor be adversely affected by the environment in which installed.

The changes did not result in more than a minimal increase in the likelihood of occurrence of a malfunction of an SSC important to safety as previously described in the FSAR. The ICS design parameters are within the environmental and seismic envelopes of the plant. Systems important to safety are not affected. Known interactions between safety and non-safety related SSCs have been addressed. The heat load, electrical load, electrical separation, redundancy, and failure effects have been determined to be acceptable by calculation and manufacturer documentation.

The changes did not result in more than a minimal increase in the consequences of an accident previously evaluated in the FSAR. The SSCs that interface with the RRP Speed Control, FWLC and RFPT Speed Control are not employed for accident prevention and mitigation. The changes do not alter the physical condition or performance of any related reactor coolant pressure boundary (RCPB) or containment. This would include reactor recirculation and feedwater piping. The changes did not affect the operations of any FSAR described safety-related components. Changes were made to the Level 8 main turbine trip and RFPT trips. The changes maintain pre-existing system functions.

System bounded conditions were maintained.

The changes did not result in more than a minimal increase in the consequences of a malfunction of an SSC important to safety as previously evaluated in the FSAR. The affected systems, by design, do not mitigate the radiological consequences of a malfunction. No new failure modes affecting radiological release have been introduced.

Annunciators and alarms alerting the Operators to system or plant parameter changes have been incorporated/retained into the ICS. Installation of the system did not have an adverse effect on the environment. A Failure Modes and Effects Analysis was performed for the ICS and related interfaces and demonstrated acceptable response.

The changes did not create a possibility for an accident of a different type than any previously evaluated in the FSAR. Enhancements for automatic operation that have been added to the system control and logic can be defaulted to manual control at any time.

Initiating events symptoms as described in FSAR Chapter 15 remain unchanged. The new digital IGS uses existing process parameter inputs and where necessary (e.g., RFPT hydraulic skids), new redundant instrumentation has been provided.

Additional redundancy and separation is provided within the ICS and provides improved reliability, availability and single point vulnerability reduction. Power sources for the primary power supplies are DC backed non-safety related sources of high quality and reliability. Separate independent power supplies the ICS secondary power supply. ICS will not have an adverse impact on the installed equipment or areas of the Control

Attachment 1 to PLA-6657 Page 3 of 3 Structure, Control Room, Computer Room, or Turbine Building. The electrical and heat loads have been evaluated by calculation and determine acceptable.

The changes did not create a possibility for a malfunction of an SSC important to safety with a different result than that previously evaluated in the FSAR. Existing analog controllers are being implemented in redundant soft control using the Foxboro/Invensys "Foxview" graphical Human Machine Interface (HMI). The ICS is a distributed control system developed using the standard 110 field interface devices (FBM Modules) and digital control logic configured using the I/A configuration tool (ICC). The new ICS control processors are redundant, fault tolerant, and reliable. The supporting mesh network (PDN) incorporates appropriate cyber-security and network monitoring features.

The ICS maintains bounding system limits and has no real or digital connections to safety-related equipment. The ICS system software was developed in accordance with PPL and Invensys Software Quality Assurance (SQA) program and is subject to the manufacturing, design, and testing requirements including Verification and Validation (V& V), Factory Acceptance Testing, Integrated Software Testing, Simulator Software Testing, and Site Acceptance Testing (SAT). The electrical and heat loads have been evaluated and determined acceptable. The soft control and operator interface (i.e., HMI) has been designed in accordance with human factors criteria to not increase burden on the operators when responding to plant conditions. Operator selectable (shortcut) buttons are available for direct access to many of the graphic displays in order to simplify and reduce graphic interface, system response and correct interface with ICS controls logic.

Operations personnel provided extensive design input to the HMI screen & overlay development and noun name nomenclature. Dedicated Operations staff were also involved in the Factory Acceptance Testing and Simulator testing.

The changes did not cause a design basis limit for a fission product barrier to be exceeded or altered. The ICS change maintains the existing system design limits and basic system hnctions. The change did not alter the operability of the recirculation system during power operation or shutdown. The ICS control processing time response and overall response time with interfacing mechanical system interfaces has been tested /

documented and is acceptable. Reactor Core System Limits, End of Cycle Recirculation Pump Trip, Anticipated Transient without Scram RPT, and Core Operating Limits are unchanged. The high Reactor vessel water level trips, which initiate a Main Turbine and recirculation pump trip, have been retained. The changes did not result in a departure from a method of evaluation described in the FSAR used in establishing the design bases or in the safety analyses. Review of the original transient analysis, presented in calculation EC-TRAN-0513 and FSAR Chapter 15, showed that a recirculation pump failure and feedwater flow control failure are assumed to be an initiating event.

Installation of the ICS did not alter the logic input assumptions used in the transient analysis.