ML042390442
| ML042390442 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 08/18/2004 |
| From: | Korsnick M Constellation Energy Group |
| To: | Clark R Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| Download: ML042390442 (7) | |
Text
Maria Korsnick 1503 Lake Road Vice President Ontario, New York 14519-9364 585.771.3494 585.771.3943 Fax maria.korsnickBconstellation.com Constellation Energy R.E. Ginna Nuclear Power Plant August 18, 2004 Mr. Robert L. Clark Office of Nuclear Regulatory Regulation U.S. Nuclear Regulatory Commission Attn:
Document Control Desk Washington, D.C. 20555-0001
Subject:
Response to Request for Additional Information (RAI) dated July 22 2004, Regarding Proposed Control Room Emergency Air Treatment System (CREATS)
Modification and Change in Dose Calculation Methodology to Alternate Source Term R.E. Ginna Nuclear Power Plant Docket No. 50-244
References:
- 1. Letter from Robert C. Mecredy (RG&E) to Robert L. Clark (NRC) dated May 21, 2003, License Amendment Request Regarding Revision of Ginna Technical Specification Sections 1.1, 3.3.6, 3.4.16, 3.6.6. 3.7.9, 5.5.10, 5.5.16, and 5.6.7 Resulting From Modification of the Control Room Emergency Air Treatment System and Change in Dose Calculation Methodology to Altemate Source Term.
- 2. Letter from Robert L Clark (NRC) to Robert C. Mecredy (RG&E) dated July 22, 2004, Request for Additional Information Regarding R.E. Ginna Nuclear Power Plant License Amendment Request Relating to the Control Room Emergency Air Treatment System Modification (TAC No. MB9123).
- 3. Letter from Robert C. Mecredy (RG&E) to Robert L. Clark (NRC) dated February 16,2004, Detailed Design Information for Proposed CREATS Modification and Locked Rotor Failed Fuel Estimation.
Dear Mr. Clark:
The attachments to this letter provide a response to the Request for Additional Information (RAls) contained in Reference 2 and further discussed during a conference call between Ginna personnel and your staff on July 15, 2004. This information demonstrates that the charcoal in the CREATS filter units is not expected to reach ignition temperature due to iodine desorption, and that the methods of fire detection, isolation, and protection are appropriate for the design and application. If you have questions regarding the content of this correspondence, please contact Mr. Mike Ruby at (585) 771-3572 or Mr. George Wrobel at (585) 771-3535.
Very truly yours, Mary rsnick I
6011 D9
STATE OF NEW YORK
- TO WIT:
COUNTY OF WAYNE 1, Mary G. Korsnick, being duly swom, state that I am Vice President - R.E. Ginna Nuclear Power Plant, LLC (Ginna LLC), and that I am duly authorized to execute and file this response on behalf of Ginna LLC. To the best of my knowledge and belief, the statements contained in this document are true and correct. To the extent that these statements are not based on my personal knowledge, they are based upon information provided by other Ginna LLC employees and/or consultants. Such information has been reviewed in accordance with company practice and I believe it to be reliable.
Subscribed and sworn before me, a Notary Public* and for the State of New York and County of 1 A-v"4-41
WITNESS my Hand and Notarial Seal:
il-/i X7ta Notary Public SHARON L MUER My Commission Expires:
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-N 146 Xt, Date Attachments:
- 1.
Response to RAls Cc:
Mr. Robert L. Clark (Mail Stop 0-8-C2)
Project Directorate I Division of Licensing Project Management Office of Nuclear Regulatory Regulation U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852 Regional Administrator, Region 1 U.S. Nuclear Regulatory Commission 475 Allendale Road King of Prussia, PA 19406 U.S. NRC Ginna Senior Resident Inspector
Mr. Peter R. Smith New York State Energy, Research, and Development Authority Corporate Plaza West 286 Washington Avenue Extension Albany, NY 12203-6399 Mr. Paul Eddy NYS Department of Public Service 3 Empire State Plaza, 10h Floor Albany, NY 12223 James M. Petro Jr.
Counsel, Generation - Nuclear Constellation Energy 750 East Pratt Street, 17th Floor Baltimore, MD 21202 Response to RAls
REQUEST FOR ADDITIONAL INFORMATION R.E. GINNA NUCLEAR POWER PLANT CONTROL ROOM EMERGENCY AIR TREATMENT SYSTEM R.E. Ginna Nuclear Power Plant, LLC proposed design modifications to the Control Room Emergency Air Treatment System, the Control Room Emergency Cooling System, and the Containment Post Accident Charcoal Filters are based on the full scope implementation of the alternate source term. The Nuclear Regulatory Commission staff has reviewed the license amendment request and has determined that the following additional information is needed.
- 1. Isolation Dampers Isolation dampers with minimal leakage are installed in the charcoal units. In the event of a fire or over heating of the charcoal filters how are the isolation dampers closed (automatically, manually)? How will the dampers be affected by fire or high temperatures (for example are they expected to leak or deform, will this create a path for combustion products to enter the control room)? How will the isolation dampers or other plant features prevent an unmitigated fire from causing smoke to enter the control room and therefore creating a challenge to plant operation?
Response
In the event of a fire in the new CREATS filter unit, temperature sensors will alarm in the Control Room so that the postulated fire can be identified, and with local manual action, can be extinguished. Additionally, the temperature sensors will automatically isolate the affected train, preventing combustion products from entering the control room. This is further described in sections 4.2.2 and 5.2.1 of the Sequence of Operation submitted as part of Attachment 1 to Reference 3.
Each new train of CREATS is isolated by redundant inlet and outlet back-draft dampers (total of four dampers per train), that are located at least 10' upstream and downstream from the carbon filter section of the new CREATS filter housing. One of the two redundant discharge dampers in each train is equipped with an actuator that holds the back-draft damper closed when the train is isolated. Inside each carbon filter housing is an upstream and downstream temperature sensor, and a fire suppression header. The suppression header is normally capped on the outside of the unit, and if suppression is required, the cap is removed and a fire hose is connected.
Leakage through the isolation dampers is unlikely due to the dampers' heavy construction (10 gage or thicker) and low leakage requirements (ASME AG-I leakage class 1). The distance from the carbon filter unit would limit the dampers' exposure to heat and reduce the chance of leakage due to warping.
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2 Fire Detection Instrumentation Will the relay room annex detection system annunciate to a constantly attended location?
Response: The new detection system will alarm at Satellite Station C located in the Relay Room. That alarm results in an alarm at Satellite Station B in the Control Room, which is a continually manned location.
- 3. Charcoal Filter Bank Fire Suppression System The new charcoal filter banks, which are the major combustible in the area of concem, will be protected by manually actuated deluge systems with spray heads mounted inside the filter housings. The NRC staffs position on this issue, as outlined in Section 4.10 of RG 1.52 is that when a water-based fire suppression or prevention system is installed in the charcoal filter housing, the fire system should be manually actuated unless there is a reasonable probability that the iodine desorption and adsorbent auto-ignition could occur in the housing, in which case the fire system should have both automatic and manual actuation. Section 4.10 of RG 1.52 further states that, the fire system should be hard piped.
Therefore, we request that you demonstrate that there is not a reasonable probability that the iodine desorption and adsorbent auto-ignition could occur in the housing. One example of an acceptable way of demonstrating this is to provide the results of your calculations that demonstrate that the highest possible temperature that could occur in the vicinity of the charcoal (including the temperature rise associated with radioactivity-induced heat in the charcoal), as a result of a design-basis accident, is lower than the iodine desorption and adsorbent auto-ignition temperature of the adsorbent. Also, we request that you demonstrate that based on Ginna's specific configuration that the arrangement of the hose connection is a reasonable substitute for hard piping of the fire protection system.
Response
R.E. Ginna Nuclear Power Plant, LLC has performed calculations to determine the heat-up of the CREATS charcoal filters due to iodine desorption. Using the conservative assumptions from the control room dose analysis, the calculations estimate the charcoal filter heat-up rate to be approximately 5.20E-7 deg F/sec. This demonstrates that with significant margin, it is essentially impossible for the CREATS filters to heat up from normal room temperature to the ignition temperature of 680 deg F from iodine desorption. Therefore, an automatic suppression system is not required.
Due to the significant difficulty and expense in hard piping the suppression system, and concerns with inadvertent actuation and wetting of the housing components, the fire suppression system will be manually actuated by connecting a fire hose between the filter housing and yard hydrant #11 located outside the east door of the Relay Room Annex. Both charcoal filter housings will be provided with a fire hose connection and isolation valve for safe and easy connection. All necessary hoses and fittings will be pre-staged for immediate use if required. This is not considered a 2
significant evolution for the Ginna Fire Brigade, and training will be conducted as part of the plant modification process to ensure familiarity with the system.
Therefore, given the low probability of a fire in the charcoal units, the methods of detection and isolation, the heavy construction of the enclosed units, and effective methods available to extinguish a fire, the current design is considered acceptable for this application.
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