GO2-07-053, Response to Request for Additional Information Regarding License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power
| ML070930295 | |
| Person / Time | |
|---|---|
| Site: | Columbia  |
| Issue date: | 03/22/2007 |
| From: | Oxenford W Energy Northwest |
| To: | Document Control Desk, NRC/NRR/ADRO |
| References | |
| GO2-07-053 | |
| Download: ML070930295 (5) | |
Text
E ENERGY M\AS'NORTHWEST IPeople
- Vision - SOnutions P.O. Box 968 9 Richland, WA
- 99352-0968 March 22, 2007 G02-07-053 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555-0001
Subject:
COLUMBIA GENERATING STATION, DOCKET NO. 50-397 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TECHNICAL SPECIFICATIONS ASSOCIATED WITH AC AND DC ELECTRICAL POWER
References:
- 1) Letter dated, May 31, 2005 G02-05-099, WS Oxenford (Energy Northwest) to NRC, "License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power"
.2) Letter dated, February 8,:2006 G2-06-019, WS Oxenford (Energy Northwest)lto0NRCý "Response to' Request forAdditional Information.
Regarding License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power"
- 3) Letter dated, January 5, 2007 G02-07-008, WS Oxenford (Energy Northwest) to NRC, "Response to Request for Additional Information Regarding License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power"
- 4) Letter dated, February 13, 2007 G02-07-027, WS Oxenford (Energy Northwest) to NRC, "Supplemental Information Regarding License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power"
- 5) Letter dated, February 22, 2007 G02-07-036, WS Oxenford (Energy Northwest) to NRC, "Response to Request for Additional Information Regarding License Amendment Request to Technical Specifications Associated with AC and DC Electrical Power"
Dear Sir or Madam:
Transmitted herewith'in-the Attachment is'the-Energy Northwest response to a Request for Additional Information (RAI)'regarding the proposed application of Tech nical.:,,,. .
Specification Task Force (TSTF)-283-A, rev. 3 in the license amendment proposed by Reference 1.
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RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TECHNICAL SPECIFICATIONS ASSOCIATED WITH AC AND DC ELECTRICAL POWER Page 2 This response provides additional justification for proposed modification of notes regarding Surveillance Requirements (SR) of Limiting Condition for Operation (LCO) 3.8.1. This was discussed with the Staff in a teleconference on March 8, 2007 during which the Staff requested additional information regarding SRs for which only portions of the testing would be performed. This response does not change the content of the license amendment request or affect the conclusion of the consideration of no significant hazards of Reference 1. There are no new commitments contained in this response.
If you have any questions or require additional information, please contact GV Cullen, Licensing Supervisor at (509) 377-6105.
I declare under penalty of perjury that the foregoing is true and correct. Executed on the date of this letter.
RespectfulIly, WS Oxenford, Vice Presiden , Technical Services Mail Drop PE08
Attachment:
Response to Request for Additional Information cc: BS Mallett - NRC RIV RN Sherman - BPA/1 399 CF Lyon - NRC NRR WA Horin - Winston & Strawn NRC Senior Resident Inspector/988C
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TECHNICAL SPECIFICATIONS ASSOCIATED WITH AC AND DC ELECTRICAL POWER Attachment Page 1 of 3 Response to Request for Additional Information Item 1 The Columbia Generating Station (CGS) Technical Specification (TS) Bases state that the reason for the note in Surveillance Requirements (SRs) 3.8.1.8 and 3.8.12 is that, during operation with the reactor critical, performance of these SRs could cause perturbations to the electrical distribution systems that could challenge continued steady state operation and, as a result, plant safety systems.
Similarly, the CGS TS Bases state that the reason for the note in SRs 3.8.1.11, 3.8.1.16, 3.8.1.18, and 3.8.1.19 is that performing the Surveillance would remove a required offsite circuit from service, perturb the electrical distribution system, and challenge plant safety systems.
On November 28, 2005, the staff requested the licensee to describe the circumstances for each of these SRs that would necessitate using the note and explain what exactly will be done at power. It is the staffs position that the licensee did not adequately answer the question in its February 8, 2006 response. In order to prepare its safety evaluation, the staff needs assurance that performance of the aforementioned SRs during all Modes of operation will not cause electrical perturbations that would challenge continued steady state operation, and, as a result, plant safety systems. The staff also needs to know which 'portions' of each SR would be credited to reestablish operability (e.g., describe the circumstances for each of these SRs that would necessitate using the note and explain what exactly will be done at power).
Response
The proposed TSTF-283-A, rev. 3 license changes would modify notes to relax mode restrictions on SRs in LCO 3.8.1 to allow testing to satisfy SRs or portions of SRs listed in item 1 above in the prohibited modes in order to re-establish operability. The notes would only be applied if an assessment determines that safety of the plant is maintained or enhanced. Specifically, the assessment must consider the potential outcomes and transients associated with a failed surveillance, a successful partial surveillance, and a perturbation of the offsite or onsite system when they are tied together or operated independently as well as the operator procedures available to cope with these potential outcomes. The potential outcomes would be measured against the avoided risk of a plant shutdown and startup using risk insights or deterministic methods. The assessment would also consider safety systems or components rendered inoperable during the testing and the potential to cause perturbations to the electrical distribution systems that could challenge steady state operation and, as a result, challenge plant safety systems. If the assessment could not demonstrate that plant safety is maintained or enhanced (i.e., the proposed testing will not cause electrical perturbations that would challenge continued steady state operation or challenge plant safety systems), the note would not be invoked and the surveillance testing would not be performed.
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TECHNICAL SPECIFICATIONS ASSOCIATED WITH AC AND DC ELECTRICAL POWER Attachment Page 2 of 3 The following are examples of conditions in which the proposed notes would be applied for performing portions of SRs 3.8.1.11, 3.8.1.12, and 3.8.1.19 in modes 1, 2, or 3.
SR 3.8.1.11 This surveillance demonstrates the "as designed" operation of the standby power sources during loss of the offsite power sources. This test verifies all actions encountered from the loss of offsite power, including shedding of non-essential loads and energization of the emergency buses and respective shutdown loads from each Diesel Generator (DG). It further demonstrates the capability of a DG to automatically start and achieve the required voltage and frequency within the specified time.
An example of a situation where the note would be applied to re-establish operability following activities such as post maintenance testing, corrective maintenance, or corrective modification would be:
Performance of testing following replacement of a portion of the DG control circuitry (governor or voltage regulator). Replacement of one of these components would require validating response characteristics with the DG powering the bus. This would require load acceptance testing for the associated DG while monitoring the voltage or frequency characteristics to demonstrate the DG would respond as designed.
SR 3.8.1.12 This surveillance demonstrates that the DG automatically starts and achieves the required voltage and frequency within the specified time from the design basis actuation signal (LOCA or ECCS initiation signal) and operates for greater than or equal to 5 minutes.
An example of a situation where the note would be applied to re-establish operability following activities such as post maintenance testing, corrective maintenance, or corrective modification would be:
Performance of testing following replacement of a portion of the diesel generator control circuitry (e.g., ECCS initiation relays). Replacement of one of these components would require re-validation of response characteristics with the DG powering the bus. This would require load acceptance testing for the associated DG while monitoring the voltage or frequency characteristics to demonstrate the DG would respond as designed.
RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO TECHNICAL SPECIFICATIONS ASSOCIATED WITH AC AND DC ELECTRICAL POWER Attachment Page 3 of 3 SR 3.8.1.19 This surveillance test demonstrates the DG operation during a loss of offsite power actuation test signal in conjunction with an EGOS initiation signal.
Examples of a situation where the note would be applied to re-establish operability following activities such as post maintenance testing, corrective maintenance, or corrective modification would be:
" Performance of testing following replacement of relays that are a part of the EGOS load sequencing logic. In this example, the testing would be restricted to exercising the relay logic only and signals that would actually affect loads (i.e.,
actuate circuit breakers) would be disabled to prevent perturbations.
- Performance of testing following replacement or corrective maintenance on the control power supply for load sequencing logic or adjustment of relay settings in the load sequencing logic. In this example, the testing would be restricted to demonstrating the ability of the control power supply to perform its design function or verification of relay settings. Any signals that would actually affect loads (i.e., actuate circuit breakers) would be disabled to prevent perturbations.