ML081930209

Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems, Proposed Alternative Course of Action

ML081930209
Person / Time
Site:	Duane Arnold
Issue date:	08/06/2008
From:	Feintuch K NRC/NRR/ADRO/DORL/LPLIII-1
To:	Richard Anderson Duane Arnold
Feintuch K, NRR/DORL/LPL3-1, 415-3079
References
GL-08-001, TAC MD7824
Download: ML081930209 (8)

Text

August 6, 2008

Mr. Richard L. Anderson Vice President Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324-9785

SUBJECT:

DUANE ARNOLD ENERGY CENTER - RE: GENERIC LETTER 2008-01, "MANAGING GAS ACCUMULATION IN EMERGENCY CORE COOLING, DECAY HEAT REMOVAL, AND CONTAINMENT SPRAY SYSTEMS," PROPOSED ALTERNATIVE COURSE OF ACTION (TAC NO. MD7824)

Dear Mr. Anderson:

On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the "subject systems") are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance.

In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR), GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the "9-month submittal") of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the "3-month submittal") of the date of the GL, describing the alternative course of action it proposes to take, including the basis for the acceptability of the proposed alternative course of action.

By letter dated May 8, 2008, FPL Energy (FPL), the licensee, submitted a 3-month response to GL 2008-01 for the Duane Arnold Energy Center (DAEC). The NRC staff's assessment of the responses for the DAEC is contained in the enclosure.

The NRC staff reviewed the licensee's proposed alternative course of action and the associated basis for acceptance and concluded that for DAEC, with the exception of the clarifications and associated requests discussed in the enclosure, they are acceptable. This letter allows the licensee to implement its proposed alternative course of action provided that implementation is consistent with the clarifications and associated requests discussed in the enclosure.

If you have any questions regarding this letter, please feel free to contact me at (301) 415-3079.

Sincerely,

/RA/ Karl Feintuch, Project Manager Plant Licensing Branch III-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-331

Enclosure:

As stated

cc: See next page

ML081930209 OFFICE NRR/LPL3-1/PM NRR/LPL3-1/LANRR/PGCB/BCNRR/DSS/DD NRR/LPL3-1/BC NAME KFeintuch THarris MMurphy JWermiel LJames DATE 7/17/2008 7/17/2008 7/31/2008 7/17/2008 8/06/2008 Duane Arnold Energy Center cc:

Mr. J. A. Stall Executive Vice President, Nuclear and Chief Nuclear Officer Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Mr. M. S. Ross Managing Attorney Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420

Ms. Marjan Mashhadi Senior Attorney Florida Power & Light Company 801 Pennsylvania Avenue, NW Suite 220 Washington, DC 20004 T. O. Jones Vice President, Nuclear Operations Mid-West Region Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408

Steven R. Catron Manager, Regulatory Affairs Duane Arnold Energy Center 3277 DAEC Road Palo, IA 52324

U. S. Nuclear Regulatory Commission Resident Inspector

=s Office Rural Route #1 Palo, IA 52324 Mr. Mano Nazar Senior Vice President and Nuclear Chief Operating Officer Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408

Mr. D. A. Curtland Plant Manager Duane Arnold Energy Center 3277 DAEC Rd. Palo, IA 52324-9785

Abdy Khanpour Vice President, Engineering Support Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408

Daniel K. McGhee Iowa Department of Public Health Bureau of Radiological Health 321 East 12th Street Lucas State Office Building, 5th Floor Des Moines, IA 50319-0075 Chairman, Linn County Board of Supervisors 930 1st Street SW Cedar Rapids, IA 52404 Peter Wells, Acting Vice President, Nuclear Training and Performance Improvement Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420 Mark E. Warner Vice President, Nuclear Plant Support Florida Power & Light Company P. O. Box 14000 Juno Beach, FL 33408-0420

Last revised July 2, 2008

ENCLOSURE NRC STAFF ASSESSMENT OF 3-MONTH RESPONSE TO GENERIC LETTER 2008-01 DUANE ARNOLD ENERGY CENTER DOCKET NO. 50-331

1.0 Background On January 11, 2008, the Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" (Agencywide Documents Access and Management System (ADAMS) Accession No. ML072910759). The GL requested licensees to submit information to demonstrate that the emergency core cooling, decay heat removal, and containment spray systems (hereinafter referred to as the "subject systems") are in compliance with the current licensing and design bases and applicable regulatory requirements, and that suitable design, operational, and testing control measures are in place for maintaining this compliance. Specifically, the GL requested licensees to provide: (1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

In accordance with Section 50.54(f) of Title 10 of the Code of Federal Regulations (10 CFR), GL 2008-01 required that each licensee submit the requested information within 9 months (hereinafter referred to as the "9-month submittal") of the date of the GL. The GL also stated that if a licensee cannot meet the requested 9-month response date, the licensee is required to provide a response within 3 months (hereinafter referred to as the "3-month submittal") of the date of the GL, describing the alternative course of action it proposes to take, including the basis for the acceptability of the proposed alternative course of action.

2.0 Licensee's Proposed Alternative Course of Action By letter dated May 8, 2008, FPL Energy Duane Arnold, LLC (FPL), the licensee, submitted a 3-month response to GL 2008-01 for the Duane Arnold Energy Center (DAEC). FPL indicated that DAEC would complete a significant amount of the requested actions, including reviews of plant design, licensing basis documentation, system operating and testing procedures, and corrective actions. However, the licensee indicated that the necessary walkdowns of some segments of piping of the subject systems could not be completed within the 9-month response time requested by GL 2008-01. The licensee cannot complete the walkdowns within the requested time because portions of the subject systems are inaccessible during power operation for one or more of the following reasons: (1) entry into the high radiation environments or an inerted atmosphere (less than 4 percent oxygen concentration); (2) scaffolding in safety sensitive area; (3) prolonged containment entries during power; or (4) the need for removal of insulation from piping. DAEC does not have a planned outage prior to October 11, 2008, and thus, there is no opportunity for performing refueling outage walkdowns or documenting the results prior to the 9-month submittal date. The licensee planned to perform walkdowns of any piping segments that are determined to need in-field verification that have not been completed prior to October 11, 2008, and complete the final documentation of any necessary walkdowns within 90 days after the restart from the next refueling outage, currently planned for early 2009.

The licensee identified that the following piping sections would be accessible during power operation and the detailed walkdowns of these accessible portions of piping could be completed within the 9-month period:

• High pressure core injection (HPCI) suction piping - condensate storage tank to pump inlet (excluding those sections that are underground and cannot be walked down)

• HPCI suction piping - suppression pool to pump inlet

• HPCI charge piping - pump outlet to steam tunnel penetration

• Core spray (CS) suction piping - suppression pool to pump inlet

• CS discharge piping - pump outlet to outboard injection valve

• residual heat removal (RHR) (low pressure core injection (LPCI) and shutdown cooling modes) discharge piping-pump outlet to outboard injection valve

• RHR (LPCI, suppression pool cooling/spray, and drywell (DW) spray modes) suction piping - suppression pool to pump inlet

• RHR (shutdown cooling mode) suction piping - outboard containment isolation valve to pump inlet

• RHR (DW spray and suppression pool cooling/spray modes) discharge piping - pump outlet to the outboard containment isolation valve for DW spray and to inboard isolation valves for suppression pool cooling/spray (the spray piping from this point inward to the respective spray spargers is exempted from the GL scope as it is open-ended and not kept full of water)

If, during the on-line scoping walkdowns, the licensee discovers some portions of the above piping sections to be inaccessible, because of physical interference, risk to plant operation, or personnel safety concerns, it will add those portions of piping to the inaccessible piping list for walkdowns during the next refueling outage.

The licensee also identified the following portions of piping as the inaccessible portions of piping:

• HPCI discharge piping - entry into steam tunnel to reactor pressure vessel (RPV)

• CS discharge piping - outboard injection valve to RPV

• RHR (LPCI and shutdown cooling modes) discharge piping - outboard injection valve to RPV

• RHR (shutdown cooling mode) suction piping - RPV to outboard containment isolation valve The licensee stated that it will complete as much of the GL 2008-01 requested actions within the requested 9-month period as is practical, based on in-plant accessibility of the subject systems. The licensee stated that the requested 9-month response to the GL would include the results of the review of the design and licensing basis documentation, operating instructions/procedures related to those for filling and venting of systems as part of return to service or re-alignment from alternate modes back to safety injection mode, and the results of the scoping and detailed walkdowns completed at that time, along with any identified corrective actions, with accompanying plans and schedule for resolution. Further, the licensee stated that it will continue to monitor industry generic efforts and will incorporate such additional information and plant-specific lessons learned from other licensees, as applicable to the DAEC. As an alternative course of action, the licensee's letter dated May 8, 2008, listed the following commitments:

(1) Complete the detailed walkdowns and evaluations of those inaccessible sections of piping of GL 2008-01 subject systems, not otherwise exempted, prior to start up from the next refueling that is currently planned for early 2009.

(2) Submit a supplemental report to the original 9-month response, for those walkdowns and evaluations completed during the 2009 refueling outage, within 90 days after startup from that outage.

The licensee stated that it has confidence that the GL subject systems at the DAEC can fulfill their required functions, based on its 30 years of operating experience, which includes walkdowns, detailed evaluations, and special testing for other regulatory issues. As such, the licensee concluded that completing performance of the detailed walkdowns and subsequent evaluations of a portion of piping sections, outside the requested 9-month period, but no later than startup from the next refueling outage that is planned for early 2009 is an acceptable alternative course of action.

3.0 NRC staff Assessment

Based on its review of the licensee's 3-month response discussed in Section 2 of this assessment, the NRC staff finds that: (1) the stated reasons for the GL 2008-01 response delay are acceptable; (2) the proposed alternative action plan and the commitments to provide a 9-month initial response by October 11, 2008, and a supplemental response within 90 days after startup from the early 2009 refueling outage meet the requested dates for the GL requested information; and (3) the described operating experience, testing, and procedures associated with managing gas accumulation at DAEC provide reasonable assurance that the GL subject systems will remain operable. Therefore, the NRC staff concluded that, with the exception of the clarifications and associated requests discussed below, the licensee's proposed alternative course of action is acceptable.

The NRC staff notes that Commitment 2 discussed in Section 2 does not clearly specify the information to be provided in its supplemental report. The NRC staff requests the licensee to submit in its 9-month supplemental (post-outage) submittal the following information: Except for the long-term items described below, provide all remaining GL requested information for the subject systems to the NRC within 90 days after startup from the 2009 refueling outage. The NRC staff requests that for each of the two requested submittals (the 9-month initial and the supplemental submittals), the licensees should provide: (1) a description of the results of evaluations that were performed in response to the GL; (2) a description of all corrective actions that the licensee determined were necessary; and (3) a statement regarding which corrective actions were completed, the schedule for completing the remaining corrective actions, and the basis for that schedule.

The NRC staff noted that the licensee's submittal dated May 8, 2008, did not mention other potential long-term actions that are identified in GL 2008-01. For instance, the industry is assessing whether it is necessary to perform pump testing to determine the allowable limits on ingested gas volume in pump suction piping, as well as, whether analysis development is needed to assess gas transport in the subject system piping as a function of system flow. It is unlikely this industry effort will be complete for the 9-month initial or supplemental submittals. Further, technical specification changes may be necessary to reflect the improved understanding achieved during response to the GL, but these cannot be fully developed for the 9-month initial or supplemental submittals. A Technical Specifications Task Force traveler may provide a generic example that can be adopted by licensees. The NRC staff requests that the licensee address in its 9-month submittal how it plans to track such long-term actions (e.g.,

Corrective Action Program and/or commitment tracking). The NRC plans to perform follow up inspections of licensee responses to GL 2008-01 at all plants using a temporary instruction inspection procedure.