ML050400642

RAI, Request for Approval of Final Safety Analysis Report Change Regarding the Carbon Dioxide Suppression System

ML050400642
Person / Time
Site:	Salem
Issue date:	02/28/2005
From:	Dan Collins NRC/NRR/DLPM/LPD1
To:	Levis W Public Service Enterprise Group
Collins D S, NRR/DLPM, 415-1427
References
TAC MC3096, TAC MC3097
Download: ML050400642 (5)

Text

February 28, 2005 Mr. William Levis Senior Vice President & CNO PSEG Nuclear - X15 P.O. Box 236 Hancocks Bridge, NJ 08038

SUBJECT:

SALEM NUCLEAR GENERATING STATION, UNIT NOS. 1 AND 2, REQUEST FOR ADDITIONAL INFORMATION RE: REQUEST FOR APPROVAL OF FINAL SAFETY ANALYSIS REPORT CHANGE REGARDING THE CARBON DIOXIDE SUPPRESSION SYSTEM AT SALEM GENERATING STATION, UNIT NOS. 1 AND 2 (TAC NOS. MC3096 AND MC3097)

Dear Mr. Levis:

By letter dated April 15, 2004, PSEG Nuclear LLC (PSEG) requested Nuclear Regulatory Commission (NRC) approval of a change to the Salem Generating Station, Unit Nos. 1 and 2, Updated Final Safety Analysis Report discussion of the carbon dioxide suppression system.

Specifically, the change involves changing the design basis of the carbon dioxide suppression system in the switchgear rooms and lower penetration areas from a 50-percent carbon dioxide concentration with a 30-minute hold time to a 27.6-percent concentration with a hold time sufficient to suppress a fire and allow the PSEG Nuclear Fire Department to respond and take proper actions.

The NRC staff has reviewed and evaluated the information provided in the April 15, 2004, application and has determined that responses to the questions in the enclosure to this letter are needed in order for the staff to complete its review. These questions were discussed between NRC and PSEG staff in a teleconference on February 1, 2005. During that conversation, it was agreed that NRC technical reviewers will make a visit to the site in order to visually observe the physical characteristics of the plant that are in question. Depending on the results of that site visit, the NRC staff may have additional questions that will require a formal response from PSEG. NRC staff is coordinating with PSEG licensing staff to determine a mutually agreeable date for this site visit. If you have any questions I can be reached at (301) 415-1427.

Sincerely,

/RA/

Daniel Collins, Senior Project Manager, Section 2 Project Directorate I Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-272 and 50-311

Enclosure:

Request for Additional Information cc w/encl: See next page

ML050400642

• memo ML050330153 OFFICE PDI-2/PM PDI-2/LA SPLB/SC PDI-2/SC NAME DCollins CRaynor SWeerakkody DRoberts DATE 2/24/05 2/24/05 2/3/05* 2/24/05 Salem Nuclear Generating Station, Unit Nos. 1 and 2 cc:

Mr. Thomas P. Joyce Dr. Jill Lipoti, Asst. Director Site Vice President - Salem Radiation Protection Programs PSEG Nuclear - X15 NJ Department of Environmental P.O. Box 236 Protection and Energy Hancocks Bridge, NJ 08038 CN 415 Trenton, NJ 08625-0415 Mr. Michael H. Brothers Vice President - Nuclear Assessments Brian Beam PSEG Nuclear - N10 Board of Public Utilities P.O. Box 236 2 Gateway Center, Tenth Floor Hancocks Bridge, NJ 08038 Newark, NJ 07102 Mr. Michael P. Gallagher Regional Administrator, Region I Vice President - Eng/Tech Support U.S. Nuclear Regulatory Commission PSEG Nuclear - N28 475 Allendale Road P.O. Box 236 King of Prussia, PA 19406 Hancocks Bridge, NJ 08038 Senior Resident Inspector Ms. Christina L. Perino Salem Nuclear Generating Station Director - Regulatory Assurance U.S. Nuclear Regulatory Commission PSEG Nuclear - N21 Drawer 0509 P.O. Box 236 Hancocks Bridge, NJ 08038 Hancocks Bridge, NJ 08038 Mr. Carl J. Fricker Jeffrie J. Keenan, Esquire Plant Manager PSEG Nuclear - N21 PSEG Nuclear - N21 P.O. Box 236 P.O. Box 236 Hancocks Bridge, NJ 08038 Hancocks Bridge, NJ 08038 Ms. R. A. Kankus Joint Owner Affairs PECO Energy Company Nuclear Group Headquarters KSA1-E 200 Exelon Way Kennett Square, PA 19348 Lower Alloways Creek Township c/o Mary O. Henderson, Clerk Municipal Building, P.O. Box 157 Hancocks Bridge, NJ 08038

REQUEST FOR ADDITIONAL INFORMATION REGARDING PROPOSED AMENDMENT REQUEST SALEM GENERATING STATION, UNIT NOS. 1 AND 2 DOCKET NOS. 50-272 AND 50-311 The Nuclear Regulatory Commission (NRC) staff has reviewed and evaluated the information provided in the April 15, 2004, application submitted by PSEG Nuclear, LLC (PSEG), and has determined that responses to the following questions are needed in order for the staff to complete its review.

PSEG has exemptions for the 460V switchgear rooms (areas 1 and 2 FA-AB-84A), lower electrical penetration areas (areas 1 and 2 FA-EP-78C), and the 4160V switchgear rooms (areas 1 and 2 FA-AB-64A). These exemptions are in place because the redundant safe shutdown systems are not protected by complete, 1-hour fire barriers. In addition, the carbon dioxide (CO2) fire suppression system in the 4160V switchgear rooms is manually actuated.

1. The National Fire Protection Agency (NFPA)-12 states that a CO2 design concentration of 50% shall be maintained for not less than 20 minutes for deep-seated fires. Testing done by Sandia National Laboratories (SNL) in 1986 (NUREG/CR-3656) also used a design concentration of 50% and that concentration was maintained for 15 minutes for Institute of Electrical and Electronics Engineers (IEEE)-383 qualified cables. In those tests, smoldering continued in the cable trays after the soak time and in one case this led to the re-ignition of the fire after the reintroduction of oxygen (deep-seated fire).

SNL testing conducted in 1982 (NUREG/CR-2431) concluded that, ...both propagation and reignition of cable fires are frequently preceded by a deep-seated fire in excess of 1 minute duration. The report also states that the use of fire retardant materials (IEEE-383 cable qualifications) tends to increase the duration of deep-seated fires.

a) Provide the technical justification for the use of a CO2 system with a 27.6%

design concentration.

b) Please explain how the level of safety will be maintained for surface fires with a CO2 system that has a 27.6% design concentration.

c) Please explain how the level of safety will be maintained for deep-seated fires with a CO2 system that has a 27.6% design concentration.

2. According to the PSEG submittal, the CO2 system was originally designed to maintain a 50% concentration for 30 minutes. With the current state of the system, the CO2 concentrations are 27.6% 14 to 30 minutes after discharge, depending on the room.

a. How much CO2 gas is leaking from each of the rooms under consideration and where is it leaking to?

b. What effect will this leakage have on plant personnel?

Enclosure

c. What effect will the discharge of the CO2 system have on the safe shutdown of the plant as well as the fire fighting actions should the fire not be extinguished with the lower CO2 concentration?

3. Describe the operator and fire brigade response to an alarm in the 4160-volt and 460-volt switchgear rooms and the lower electrical penetration areas.

4. The PSEG request states (page 5) that, Smoldering solids are extinguished by Fire Department action that typically includes application of water for rapid cooling and removal/reduction of debris. Fire suppression without reflash will be successful when rapid suppression of open flames occurs and CO2 concentration is maintained to prevent flaming combustion.

a. Are all of the areas under consideration equipped with floor drains?

b. If there are floor drains in these areas, what are the sizes and quantities in each area?

c. If there are no floor drains in these areas, how will this impact the possible use of water by the fire brigade?

d. Will water coming out of any of the rooms under consideration impact any safe shutdown systems?

e. In previous instances of electrical/cable fires at other plants the fire brigades have been reluctant to use water. What assurances can you provide that water will be applied to fires not immediately extinguished by the CO2 system?

5. The PSEG submittal states (page 7) that, Because the Fire Department responds to the first alarm (including smoke detector alarms) in any of these rooms, the response of the Fire Department will typically begin prior to CO2 discharge.

a. Does this mean that normally the fire department is expected to extinguish the fires instead of the suppression system?

b. Is the first line of defense against a fire the CO2 suppression system or the fire department?

6. The PSEG submittal states (page 4) that On March 28, 2003, Engineering Evaluation S-C-FP-FEE-1748, CO2 System Operability in Switchgear Rooms and Lower Penetration Areas, was completed to assess the current conditions of the carbon dioxide system in the Switchgear Rooms and Lower Electrical Penetration Areas. This evaluation was never formally submitted to the NRC. Please formally submit this document to the NRC.