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{{Adams
#REDIRECT [[1CAN030905, Post-Outage Supplemental Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems, Arkansas Nuclear One]]
| number = ML090760502
| issue date = 03/16/2009
| title = Post-Outage Supplemental Response to NRC Generic Letter 2008-01, Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems, Arkansas Nuclear One
| author name = Mitchell T G
| author affiliation = Entergy Operations, Inc
| addressee name =
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000313
| license number = DPR-051
| contact person =
| case reference number = 1CAN030905, GL-08-001
| document type = Letter
| page count = 3
}}
 
=Text=
{{#Wiki_filter:1CAN030905  
 
March 16, 2009 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC  20555
 
==SUBJECT:==
Post-Outage Supplemental Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems" Arkansas Nuclear One, Unit 1
 
Docket No. 50-313 License No. DPR-51
 
==REFERENCE:==
: 1. Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems", dated January 11, 2008 (0CNA010801)
: 2. Nine-Month Response to NRC Generic Letter 2008-01, "Managing Gas Accumulation in Emergency Core Cooling, Decay Heat Removal, and Containment Spray Systems", dated October 14, 2008 (0CAN100801)
 
==Dear Sir or Madam:==
 
The U. S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 2008-01 (Reference 1) to request that each licensee evaluate the licensing basis, design, testing, and corrective action programs for the Emergency Core Cooling Systems (ECCS), Decay Heat Removal (DHR) system or Shutdown Cooling (SDC) system, and Containment Spray system, to ensure that gas accumulation is maintained less than the amount that challenges operability of these systems, and that appropriate action is taken when conditions adverse to quality are identified.
 
Entergy Operations, Inc., (Entergy) provided the GL 2008-01 required nine-month response for Arkansas Nuclear One, Units 1 and 2 (ANO-1 and 2) in Reference 2. As committed to in Reference 2, ANO-1 has completed its assessments of the inaccessible while at power portions of these systems during the Fall 2008 refueling outage. This supplemental information is being provided within 90 days of the startup from the outage. These activities are considered to be confirmatory.
 
Entergy Operations, Inc. 1448 S.R. 333 Russellville, AR  72802 Tel  479-858-3110 Timothy G. Mitchell Vice President, Operations Arkansas Nuclear One
 
1CAN030905 Page 2 of 3
 
In consideration of the walkdowns during the outage, data reviews, and additional operational data results, Entergy concludes that the subject ANO-1 systems are being operated and maintained in such a way as to minimize the presence of gas voids. In addition, it is further concluded that these systems are fully operable in regards to the nuclear industry gas voiding concerns. Except for the Sodium Hydroxide (NaOH) outlet gas voids, there were no additional ANO-1 condition reports generated as a result of the walkdowns and assessments during the outage.
 
The voids in the NaOH system are downstream of the isolation valves and the point where the NaOH piping connects to the suction piping of the Building Spray and Low Pressure Injection (LPI) pumps (~0.1 ft 3 and ~0.52 ft 3). In the evaluation of the voids, it was assumed that the voids were air bubbles resulting from the vent/fill operations at the end of the last refueling outage. It was determined that the voids were below the operability limits for each line. The acceptance criteria developed for this evaluation is that an acceptable volume fraction of gas is 10% by volume for no more than 5 seconds. Based on this, the maximum volume of air permissible in 5 seconds for the Spray pump is 1.67 ft
: 3. For the LPI pump, a maximum of 3.34 ft 3 in 5 seconds is acceptable. The voids that were found in the system were significantly smaller than the allowable volume. These voids do not challenge the structural operability of the affected systems. No mechanisms were identified that is increasing the volume of the voids.
 
Any procedure revisions related to the filling and venting of the subject systems are considered to be enhancements.
 
In summary, Entergy has concluded that the subject systems at ANO-1 are operable and that ANO-1 is currently in compliance with the licensing basis documentation and applicable regulations, including 10 CFR 50 Appendix B, Criteria III, V, XI, XVI, and XVII, with respect to the concerns outlined in GL 2008-01 regarding managing gas accumulation in these
 
systems/functions.
 
The next refueling outage for ANO-2 is scheduled for the Fall of 2009. The supplemental information for ANO-2 will be provided to the NRC as previously committed.
This supplemental response does not include any new commitments.
 
If you have any questions or require additional information, please contact David Bice 
 
at 479-858-4710.
I declare under penalty of perjury that the foregoing is true and correct. Executed on
 
March 16, 2009.
 
Sincerely,  TGM/rwc 1CAN030905 Page 3 of 3
 
cc: Mr. Elmo E. Collins  Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400  Arlington, TX  76011-4125
 
NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR  72847
 
U. S. Nuclear Regulatory Commission Attn: Mr. Alan B. Wang MS O-7 D1 Washington, DC  20555-0001
 
Mr. Bernard R. Bevill
 
Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR 72205}}

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