ML042170402
| ML042170402 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 07/30/2004 |
| From: | Shukla G NRC/NRR/DLPM/LPD4 |
| To: | Rueger G Pacific Gas & Electric Co |
| Shukla G, NRR/DLPM/LPDIV-2/415-8439 | |
| Shared Package | |
| ML042180405 | List: |
| References | |
| TAC MC3895 | |
| Download: ML042170402 (15) | |
Text
July 30, 2004 Mr. Gregory M. Rueger Senior Vice President, Generation and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Nuclear Power Plant P. O. Box 3 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT, UNIT NO. 2 - ISSUANCE OF AMENDMENT RE: REVISION TO TECHNICAL SPECIFICATION 3.6.6, "CONTAINMENT SPRAY AND COOLING SYSTEMS" (TAC NO. MC3895)
Dear Mr. Rueger:
The Commission has issued the enclosed Amendment No. 173 to Facility Operating License No. DPR-82 for the Diablo Canyon Nuclear Power Plant (DCPP) Unit No. 2. The amendment is in response to your application dated July 30, 2004, and its supplement dated July 30, 2004.
The amendment authorizes a one-time change to the completion time of Required Action A.1 of Technical Specification (TS) 3.6.6, "Containment Spray and Cooling Systems," to increase the completion time for the DCPP Unit 2 Containment Spray Pump (CSP) 2-2 from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. Your application requested that this amendment be treated as an emergency.
Based upon your application, the staff concludes that your proposed amendment meets the requirements of 10 CFR 50.91(a)(5) in that failure of the staff to act in a timely manner on your request would result in the shutdown of DCPP Unit 2 and the emergency situation could not have been avoided.
A copy of the related Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commission's next regular biweekly Federal Register notice.
Sincerely,
/RA/
Girija S. Shukla, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-323
Enclosures:
- 1. Amendment No. 173 to DPR-82
- 2. Safety Evaluation cc w/encls: See next page
July 30, 2004 Mr. Gregory M. Rueger Senior Vice President, Generation and Chief Nuclear Officer Pacific Gas and Electric Company Diablo Canyon Nuclear Power Plant P. O. Box 3 Avila Beach, CA 93424
SUBJECT:
DIABLO CANYON NUCLEAR POWER PLANT, UNIT NO. 2 - ISSUANCE OF AMENDMENT RE: REVISION TO TECHNICAL SPECIFICATION 3.6.6, "CONTAINMENT SPRAY AND COOLING SYSTEMS" (TAC NO. MC3895)
Dear Mr. Rueger:
The Commission has issued the enclosed Amendment No. 173 to Facility Operating License No. DPR-82 for the Diablo Canyon Nuclear Power Plant (DCPP) Unit No. 2. The amendment is in response to your application dated July 30, 2004, and its supplement dated July 30, 2004.
The amendment authorizes a one-time change to the completion time of Required Action A.1 of Technical Specification (TS) 3.6.6, "Containment Spray and Cooling Systems," to increase the completion time for the DCPP Unit 2 Containment Spray Pump (CSP) 2-2 from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days. Your application requested that this amendment be treated as an emergency.
Based upon your application, the staff concludes that your proposed amendment meets the requirements of 10 CFR 50.91(a)(5) in that failure of the staff to act in a timely manner on your request would result in the shutdown of DCPP Unit 2 and the emergency situation could not have been avoided.
A copy of the related Safety Evaluation is enclosed. The Notice of Issuance will be included in the Commission's next regular biweekly Federal Register notice.
Sincerely,
/RA/
Girija S. Shukla, Project Manager, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-323 DISTRIBUTION:
PUBLIC GHill (2)
Enclosures:
- 1. Amendment No. 173 to DPR-82 PDIV-2 Reading
- 2. Safety Evaluation RidsNrrDlpmPdiv (HBerkow)
RidsNrrPMGShukla cc w/encls: See next page RidsNrrLAEPeyton RidsOgcRp RidsAcrsAcnwMailCenter Package No.: ML042180405 RidsRegion4MailCenter (B. Jones)
TS Pages: ML042180191 Nrr-100 MTschiltz ACCESSION NO.: ML042170402 Nrr058 OFFICE PDIV-2/PM PDIV-2/LA SPSB OGC PDIV-2/SC NAME GShukla EPeyton DHarrison AHodgdon SDembek DATE 7/30/04 7/30/04 7/30/04 7/30/04 7/30/04 DOCUMENT NAME: E:\Filenet\ML042170402.wpd
OFFICIAL RECORD COPY Diablo Canyon Power Plant, Unit 2 cc:
NRC Resident Inspector Diablo Canyon Power Plant c/o U.S. Nuclear Regulatory Commission Richard F. Locke, Esq.
P.O. Box 369 Pacific Gas & Electric Company Avila Beach, CA 93424 P.O. Box 7442 San Francisco, CA 94120 Sierra Club San Lucia Chapter c/o Henriette Groot Mr. David H. Oatley, Vice President 1000 Montecito Road and General Manager Cayucos, CA 93430 Diablo Canyon Power Plant P.O. Box 56 Ms. Nancy Culver Avila Beach, CA 93424 San Luis Obispo Mothers for Peace City Editor P.O. Box 164 The Tribune Pismo Beach, CA 93448 3825 South Higuera Street P.O. Box 112 Chairman San Luis Obispo, CA 93406-0112 San Luis Obispo County Board of Supervisors Mr. Ed Bailey, Chief Room 370 Radiologic Health Branch County Government Center State Department of Health Services San Luis Obispo, CA 93408 P.O. Box 997414 (MS 7610)
Sacramento, CA 95899-7414 Mr. Truman Burns Mr. Robert Kinosian Mr. James D. Boyd, Commissioner California Public Utilities Commission California Energy Commission 505 Van Ness, Room 4102 1516 Ninth Street (MS 31)
San Francisco, CA 94102 Sacramento, CA 95814 Diablo Canyon Independent Safety Mr. James R. Becker, Vice President Committee Diablo Canyon Operations ATTN: Robert R. Wellington, Esq. and Station Director Legal Counsel Diablo Canyon Power Plant 857 Cass Street, Suite D P.O. Box 3 Monterey, CA 93940 Avila Beach, CA 93424 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Harris Tower & Pavillion 611 Ryan Plaza Drive, Suite 400 Arlington, TX 76011-8064
PACIFIC GAS AND ELECTRIC COMPANY DOCKET NO. 50-323 DIABLO CANYON NUCLEAR POWER PLANT, UNIT NO. 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 173 License No. DPR-82
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment by Pacific Gas and Electric Company (the licensee) dated July 30, 2004, and its supplement dated July 30, 2004, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's regulations set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
- 2. Accordingly, the license is amended by changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. DPR-82 is hereby amended to read as follows:
(2) Technical Specifications The Technical Specifications contained in Appendix A and the Environmental Protection Plan contained in Appendix B, as revised through Amendment No.
173, are hereby incorporated in the license. Pacific Gas and Electric Company shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan, except where otherwise stated in specific license conditions.
- 3. This license amendment is effective as of its date of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Stephen Dembek, Chief, Section 2 Project Directorate IV Division of Licensing Project Management Office of Nuclear Reactor Regulation
Attachment:
Changes to the Technical Specifications Date of Issuance: July 30, 2004
ATTACHMENT TO LICENSE AMENDMENT NO. 173 TO FACILITY OPERATING LICENSE NO. DPR-82 DOCKET NO. 50-323 Replace the following pages of the Appendix A Technical Specifications with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
REMOVE INSERT 3.6-13 3.6-13 3.6-14 3.6-14
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 173 TO FACILITY OPERATING LICENSE NO. DPR-82 PACIFIC GAS AND ELECTRIC COMPANY DIABLO CANYON NUCLEAR POWER PLANT, UNIT 2 DOCKET NO. 50-323
1.0 INTRODUCTION
By application and its supplement dated July 30, 2004, Pacific Gas and Electric Company (the licensee) requested changes to the Technical Specifications (TSs) (Appendix A to Facility Operating License No. DPR-82) for the Diablo Canyon Power Plant (DCPP), Unit 2. The amendment would provide a one-time change to the completion time (CT) of Required Action A.1 of TS 3.6.6, "Containment Spray and Cooling Systems," to increase the CT for the Unit 2 Containment Spray Pump (CSP) 2-2 from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and 10 days from discovery of the failure to meet the limiting condition of operation (LCO) to 14 days and 14 days, respectively, to complete control circuit cable maintenance. The letter requested that this amendment be treated as an emergency because insufficient time exists for the Commission's usual 30-day notice.
Specifically, the proposed change would revise the CT of Action A.1 of TS 3.6.6 to add a Note stating: "The Condition A Completion Times may be extended to 14 days for Unit 2 cycle 12 for containment spray pump 2-2 control circuit cable maintenance."
2.0 REGULATORY EVALUATION
The regulatory evaluation that the staff applied in its review of the licensees proposed change is consistent with the objectives of the staffs Probability Risk Assessment (PRA) Policy Statement, "Use of Probabilistic Risk Assessment Methods in Nuclear Activities: Final Policy Statement." The staff based its acceptance of the licensees request on guidance in Regulatory Guide (RG) 1.177, "An Approach for Plant-Specific Risk-Informed Decisionmaking:
Technical Specifications" and RG 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk-Informed Decisions on Plant-Specific Changes to the Licensing Basis."
3.0 TECHNICAL EVALUATION
The staff has reviewed the licensees analyses in support of its proposed license amendment, which are described in Section 5.0 of the licensees submittal. The evaluation described in this section supports the conclusion that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
3.1 Risk Review Methodology The staff reviewed the submittal using an approach based on RG 1.177 and Standard Review Plan (SRP) Chapter 16.1, "Risk-Informed Decisionmaking: Technical Specifications." The staff first evaluated the licensees PRA and the impact of the change on plant operational risk, as expressed by the change in core damage frequency (CDF) and the change in large early release frequency (LERF). The change in risk is compared against the acceptance guidelines presented in RG 1.174. This evaluation also aims to ensure that plant risk does not increase unacceptably during the period when equipment is taken out-of-service (OOS) in accordance with the license amendment, as expressed by the incremental conditional core damage probability (ICCDP) and incremental conditional large early release probability (ICLERP). The incremental risk is compared against the acceptance guidelines presented in RG 1.177.
The staff also addressed the need to preclude potentially high-risk plant configurations that could result if equipment, in addition to that associated with the proposed license amendment, is taken OOS simultaneously, or if other risk-significant operational factors, such as concurrent system or equipment testing, are also involved. The objective of this part of the review is to ensure that adequate programs and procedures are in place for identifying risk-significant plant configurations resulting from maintenance or other operational activities and taking appropriate measures to avoid such configurations.
3.2 Technical Evaluation In this section the staff evaluates the impact of the proposed TS changes on plant operational risk. The staff review involves three aspects: (1) evaluation of the validity of the PRA and its application to the proposed TS changes, (2) evaluation of the PRA results and insights stemming from its application, and (3) evaluation of the configuration risk management to ensure potentially high-risk plant configurations are avoided.
3.2.1 PRA Capability To determine whether the PRA used in support of the proposed TS change is of sufficient quality, scope, and detail, the staff evaluated the relevant information provided by the licensee in their submittal and considered the findings of recent PRA reviews. The staffs review of the licensees submittal focused on the capability of the licensees PRA model to analyze the risks stemming from the proposed TS change and did not involve an in-depth review of the
licensees PRA.
The licensee used the Diablo Canyon PRA (DCPRA) model to assess the risk increase associated with the proposed TS change. This model is an at-power Level I internal events risk model that is applicable to DCPP Unit 2. The DCPRA also includes an evaluation of containment performance. A simplified LERF model, based on the Level 2 PRA, is used for calculating LERF. However, the impact of external events was not included in this license application for the following reasons:
! None of the fire events considered result in an inside containment pressurization event.
! Since the piping inside containment is robust, a seismic event severe enough to cause an inside containment pipe rupture would have a significant impact on the other safety-related equipment, such that it would make the containment spray train unavailability inconsequential.
The DCPRA is based on the original 1988 Diablo Canyon PRA that was performed as part of the long-term seismic plan. The DCPRA was subsequently updated to support the individual plant examination (IPE) in 1991 and the individual plant examination for external events (IPEEE) in 1993. Since 1993, several other updates have been made to incorporate plant and procedure changes, update plant-specific reliability and unavailability data, improve fidelity of the model, incorporate comments from the Westinghouse Owners Group (WOG) peer review that was performed in 2000, and support other applications, such as on-line maintenance, risk-informed inservice inspection, and a recent diesel generator completion time extension.
In addition, the DCPRA is a living PRA that is maintained through a periodic review and update process. The licensee states that they are confident that the risk evaluation results used to support the requested proposed license amendment are technically sound and consistent with the expectations for PRA quality set forth in RG 1.177 and RG 1.174 due to the sound basis of the original model as documented in NUREG-0675 (SSER-34), "Safety Evaluation Report Related to the Operation of the Diablo Canyon Nuclear Power Plant Units 1 and 2," June 1991, and NUREG/CR-5726, "Review of the Diablo Canyon Probabilistic Risk Assessment," August 1994, and the considerable effort to incorporate the latest industry insights into the PRA, self-assessments, and certification peer reviews. Based on the information submitted by the licensee, the staff finds that the quality of the PRA is acceptable for this application.
3.2.2 PRA Results and Insights An acceptable approach to risk-informed decisionmaking is to show that the proposed change to the licensing basis meets several quantitative acceptance guidelines including: changes in CDF and change in LERF, ICCDP, and ICLERP. The licensee used its DCPRA model to calculate risk increases due to the proposed one-time CT extension. The baseline CDF is approximately 7.65E-6/reactor-year and the baseline LERF is approximately 4.85E-7/reactor-year.
Based on the proposed 14-day CT requested, the results are:
ICCDP: 3.8E-12 ICLERP: (no change in calculated results)
The changes in CDF and LERF are numerically equal (approximately) to the assessed ICCDP and ICLERP values, respectively, due to the one-time nature of the request. These very small changes are due to the fact that the containment spray system, as modeled in the Level 1 portion of the DCPRA, only impacts the time at which operator action is required to perform the switchover to recirculation. If the licensee had performed a more detailed analysis that considered the impact on this timing due to the inoperability of CSP 2-2 (i.e., there would be more time before needing to switchover and thus improve the likelihood of successful operator action), it is likely that the analysis would have resulted in a reduction in the calculated risk metrics.
The acceptance guidelines from RG 1.177 are 5.0E-7 for ICCDP and 5.0E-8 for ICLERP, respectively, for very small increases. Likewise, for very small changes, the acceptance guidelines from RG 1.174 are 1.0E-6/reactor-year for change in CDF and 1.0E-7/reactor-year for change in LERF. Thus, the risk metrics determined by the licensee are well within the acceptance guidelines for temporary increases.
3.2.3 Risk-Informed Configuration Risk Management The licensees adherence to the current TS requirements will prevent many of the more risk-significant configurations from becoming manifest. The licensee has specifically identified potential configurations that should be avoided while a CS train is OOS. These configurations are: (1) unavailability of any containment fan cooling units (CFCUs), and (2) any activities that could reduce the availability of the other CS train. Thus, except for emergent conditions resulting from equipment failure, it is highly unlikely that more risk-significant configurations will be entered. Even under these unexpected conditions, it is likely that a more restrictive LCO would be entered, requiring corrective action to be taken to return equipment to operable status.
The intent of the risk-informed configuration risk management is to ensure that plant safety is maintained and monitored during an extended outage. The licensee has developed a process for on-line risk assessment and management. Following the process and procedures ensures that the risk impact of equipment OOS while the plant is on-line is appropriately evaluated prior to performing any maintenance activity or following an equipment failure or other internal or external event that impacts risk. Procedure AD7.DC6 provides guidance for managing safety function, probabilistic risk, and plant trip risks as required by 10 CFR 50.65(a)(4). The procedure addresses risk management practices in the maintenance planning phase and maintenance execution (real time) phase for Modes 1 through 4. Appropriate consideration is given to equipment unavailability, operational activities such as testing, and weather conditions. In general on-line maintenance risk is reduced by:
S Performing only those preventive and corrective maintenance actions on-line required
to maintain the reliability of systems, structures and components (SSCs).
S Reducing cumulative unavailability of safety-related and risk-significant SSCs by limiting the number of at-power maintenance outage windows per cycle per train/component.
S Reducing the total number of SSCs OOS at the same time.
S Reducing the risk of initiating plant transients (trips) that could challenge safety systems by implementing compensatory measures.
S Avoiding higher risk combinations of OOS SSCs using PRA insights.
S Maintaining defense-in-depth by avoiding combinations of OOS SSCs that are related to similar safety functions or that affect multiple safety functions.
S Scheduling train/bus windows to avoid removing equipment from different trains simultaneously.
Licensee actions are taken and appropriate attention is given to configurations and situations commensurate with the level of risk as evaluated using procedure AD7.DC6. This occurs both during planning and real time phases. Risk is evaluated, managed, and documented for all activities or conditions, based on the current plant state:
S Before any planned or emergent maintenance is to be performed.
S As soon as possible when an emergent plant condition is discovered.
S As soon as possible when an external or internal event or condition is recognized.
Compensatory measures are implemented as necessary and, if the risk assessment reveals unacceptable risk, a course of action is determined to restore degraded or failed safety functions and reduce risk.
The licensee has a process for online risk assessment and management. Following this process and associated procedures ensures that the risk impact of equipment unavailability is appropriately evaluated prior to performing any maintenance activity or following an equipment failure or other internal or external event that impacts risk. The programs in place for DCPP comply with 10 CFR 50.65(a)(4) to assess and manage risk from proposed maintenance activities. These programs can support the licensees decisionmaking regarding the appropriate actions to control risk whenever a risk-informed TS is entered.
3.3 Deterministic Evaluation The licensees July 30, 2004, letter states that during a design basis loss-of-coolant accident, a minimum of two CFCUs and one containment spray train is required to maintain the containment peak pressure and temperature below the design limits. One containment spray train is also required to remove iodine from the containment atmosphere to maintain the iodine
concentration below the concentration assumed in the radiological dose analyses. The CSPs take suction from the refueling water storage tank (RWST) following a loss-of-coolant accident
(LOCA). The CSPs are not used for the recirculation phase of the LOCA when the emergency core cooling system pumps take suction from the containment sump.
Normally, two containment spray trains and the CFCU system consisting of four CFCUs or three CFCUs, each supplied by a different vital bus, are operable. However, in the event of an accident, if at least one train of containment spray and two CFCUs operate, design basis acceptance criteria for containment pressure and radiological releases will be satisfied.
Consequently, during the period that the CSP 2-2 is inoperable, design basis acceptance criteria will continue to be met if the remaining CSP remains operable along with the necessary complement of CFCUs.
With the inoperability of CSP 2-2, one CSP and all CFCUs remain operable. Section 6.2.2.1 of the DCPP FSAR Update states that any single failure (of the containment spray system and the CFCU system) will still leave sufficient capability to mitigate design basis accidents. Thus, the failure of the CSP 2-2 does not impact the capability of the DCPP heat removal system to mitigate design basis accidents.
The TS change proposed by the licensee consists of the following note added to the completion time for Required Action A.1 of LCO 3.6.6, Containment Spray and Cooling Systems:
The Condition A Completion Times may be extended to 14 days for Unit 2 Cycle 12 for containment spray pump 2-2 control circuit cable maintenance.
This note requires the remaining containment spray train to remain operable. Action C of LCO 3.6.6 allows one required CFCU system to be inoperable as long as two CFCUs remain operable. With this action statement satisfied, and with a train of containment spray inoperable, the containment heat removal system will maintain the containment peak pressure and temperature below the design limits.
Therefore, from the perspective of the design basis analyses described in the DCPP FSAR Update, the proposed TS change is acceptable because the results of the design basis events will remain within their acceptance criteria.
3.4 Summary The staff finds that the licensees proposed TS change is acceptable because (1) the failure of the CSP 2-2 does not impact the capability of the DCPP heat removal system to mitigate design basis accidents; (2) the acceptance guidelines of RG 1.174 and RG 1.177 are met; (3) the licensee has taken compensatory measures limiting activities that have the potential to result in a plant transient or adversely impact the availability of the remaining CSP and CFCUs; and (4) the licensee has an adequate configuration risk management program in place which will ensure that plant evolutions during the period of the CSP repair will not increase risk unacceptably.
4.0 EMERGENCY CIRCUMSTANCES This license amendment request is submitted on an emergency basis to allow completion of maintenance on the CSP 2-2 supply breaker control circuit cable without forcing DCPP Unit 2 to shut down. As discussed in the licensee's July 30, 2004, letter, extending the Required Action A.1 CT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days in TS 3.6.6 results in no significant increase in risk.
The original ground in the control circuit cable for CSP 2-2 was identified on conductor 2-1 on June 4, 2004. Since this conductor provides indication only, and no breaker control functions, CSP 2-2 was determined to be operable. However, a temporary modification was designed to bypass the grounded conductor. On July 28, 2004, CSP 2-2 was declared inoperable to install the temporary modification to bypass conductor 2-1, so that it could be removed from service.
During post-maintenance testing of the temporary modification, additional conductors in the nine-conductor cable were identified as having grounds. The newly identified grounded conductors provide breaker control functions. As a result, the CSP 2-2 could not be returned to operable status. Thus, CSP 2-2 remains in Condition A, 72-hour CT, of TS 3.6.6.
Upon discovery of the additional grounds, a troubleshooting team conducted the investigation to mainly identify a specific location in the approximately 550 foot length of the conduit where cable degradation was evident. Late on July 29, 2004, a conduit pull box was found with water inside. Boroscope inspection of the affected conduit identified a section of the conduit full of water. The water was drained and the circuits measured for grounds. Removal of the water resulted in the ground readings improving.
As a result, the licensee is replacing the entire 550 foot cable. Installation of the new cable will require more than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> and the estimated completion time is approximately nine days. An additional margin is needed to allow for rework and retesting, if needed. Therefore, the licensee requested extending the Required Action A.1 CT from 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> to 14 days.
The staff has reviewed the licensee's basis for the proposed amendment meeting the requirements in 10 CFR 50.91(a)(5) for an emergency amendment. The staff concludes that failure to act will result in the shutdown of DCPP Unit 2, and that the licensee could not have acted in a timely manner to avoid the need for an emergency TS change. Thus, the staff does not believe that the licensee has abused the emergency provisions in this instance.
Accordingly, the staff has determined that the licensee has met the conditions of 10 CFR 50.91(a)(5) warranting prompt approval by the Commission.
5.0 FINAL NO SIGNIFICANT HAZARDS DETERMINATION The Commission's regulations in 10 CFR 50.92 state that the Commission may make a final determination that a license amendment involves no significant hazards considerations, if operation of the facility, in accordance with the amendment would not:
(1) Involve a significant increase in the probability or consequences of any accident previously evaluated; or
(2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
The amendment has been evaluated against the standards in 10 CFR 50.92. It does not involve a significant hazards consideration because the changes would not:
- 1. Involve a significant increase in the probability or consequences of an accident previously evaluated. The requested action does not physically alter any plant structures, systems, or components, and does not affect or create new accident initiators or precursors. The CT to perform a required action is not an accident initiator; therefore, there is no effect on the probability of accidents previously evaluated.
The containment spray system is required to mitigate the consequences of accidents previously evaluated in the Final Safety Analysis Report Update. The requested action to allow CSP 2-2 to be inoperable for up to 14 days does not significantly increase the consequences of those accidents due to the low probability of an accident occurring during the time of pump inoperability.
Additionally, the redundant containment spray train remains operable and capable of performing its required function. The requested action does not affect the types or amounts of radionuclides released following an accident, or the initiation and duration of their release.
Therefore, the proposed change does not result in a significant increase in the probability or consequences of an accident previously evaluated.
- 2. Create the possibility of a new or different kind of accident from any previously evaluated. The proposed change to allow CSP 2-2 to be inoperable for up to 14 days does not introduce new failure modes or mechanisms associated with plant operation. Furthermore, the 14 day CT associated with the restoration of the Unit 2 containment spray train would not create a new accident type.
Therefore, the proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.
- 3. Involve a significant reduction in a margin of safety. The proposed change has no significant risk associated with extending the Condition A CT to 14 days.
Although the proposed action deviates from a requirement in TS 3.6.6, it does not affect any safety limits, other operational parameters, or setpoints in the TS, nor does it affect any margins assumed in the accident analyses. The redundant containment spray train is operable and therefore able to perform its required design function.
Therefore, the proposed change do not involve a significant reduction in a margin of safety.
Accordingly, based on the above evaluation, the Commission has determined that this amendment involves no significant hazards considerations.
6.0 STATE CONSULTATION
In accordance with the Commission's regulations, the California State official was notified of the proposed issuance of the amendments. The State official had no comments.
7.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to the installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendment involves no significant increase in the amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has made a final no significant hazards consideration finding with respect to the amendment. Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
8.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: Mark Caruso Donald Harrison Richard Lobel Date: July 30, 2004