IR 05000259/1989028
| ML18033A956 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 09/13/1989 |
| From: | Hubbard G, Miller W, Notley D, Wescott R Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18033A955 | List: |
| References | |
| 50-259-89-28, 50-260-89-28, 50-296-89-28, GL-86-10, NUDOCS 8909210125 | |
| Download: ML18033A956 (15) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 UNITED STATES NUCLEAR REGULATORY COMMISSION OFFICE OF NUCLEAR RFACTOR REGULATION TVA PROJECTS DIVISION Report NoseI 50-259/89-028, 50-260/89-028 and 50-296/89-028 Licensee:
Tennessee Valley Authority 6N 38A Lookout Place 1101 Market Street Chattanooga, TN 37401-2801 Docket Nos:
50-259, 50-260 and 50-296 License Nos:
DPR-33, DPR-52 and DPR-68 Licensee:
Tennessee Valley Authority Facility Name:
Browns Ferry Nuclear Plant Units 1, 2 and
Inspection Conducted:
July 17-21, 1989 Inspectors:
Rex
. Wescott, earn Lea er iam i
er ate av~
o ey Approved by:
WCr~ (. ~ i+v~~lr'~~6 eorge
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,
>e Plant Systems Branch TVA Projects Division Office of Nuclear Reactor Regulation
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SUMMARY This special announced inspection was conducted in the area of fire protection to evaluate Unit 2 for compliance with Section III.G and IIIeJ of Appendix R
to 10 CFR 50.
Compliance with the postfire shutdown related requirements of III.G and IIIeL of Appendix R to 10 CFR 50 was evaluated during the Hay 1-5, 1989 inspection.
This inspection is specifically for Unit 2 restart, with Units 1 and 3 shutdown and not having returned to criticality from the present outage.
The basis for this inspection is the staff exemption Safety Evaluation issued on October 21, 1988, the licensee's Appendix R engineering evaluations and the NFPA code deviation submittals and staff replies.
Results:
As a result of this inspection, Browns Ferry Nuclear Plant Unit 2 was found to be in compliance with Appendix R to 10 CFR 50 contingent upon successful resolution of open items listed in this section.
The inspection findings were as follows:
One unresolved item was identified:
50-259 89-28-01, 50-260 89-28-01 and 50-296/89-28-01:
Potential failure to meet Section I.
. 1 o
R 50 Appen ix
,
aragraph 2.0.
Five inspector follow-up items were identified:
50-259/89-28-02, 50-260 89-28-02 and 50-296 89-28-02:
Completion of cable and conduit reroute or wrap mo i ication, aragrap 5.0.
50-259/89-28-03, 50-260 89-28-03 and 50-296 89-28-03:
Completion of seals for e ectrica raceways an mec anica ire arrier penetration, Paragraph 5.0.
50-259/89-28-04, 50-260/89-28-04 and 50-296/89-28-04:
Completion of emergency ighting insta ation, Paragraph 5.0.
50-259/89-28-05, 50-260/89-28-05 and 50-296 89-28-05:
Completion of modifications to fire doors and dampers, Paragrap 5.0.
50-259 89-28-06, 50-260 89-28-06 and 50-296 89-28-06:
Completion of mo i ications or automatic sprin er an etection systems, Paragraph 5.0.
One inspector follow-up item from a previous inspection was closed:
IFI 50-259 89-13-07, 50-260 89-13-07 and 50-296/89-13-07:
Installation of an a
itiona emergency ight on the remote s ut own pane
, Paragraph REPORT DETAILS PERSONS CONTACTED Licensee Employees
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- CD Turner, Licensing Engineer Massey, Appendix R Project Manager Gomez, Electrical Engineer Pierce, Appendix R Engineering Specialist Zeringue, Site Director Weber, Engineering and Modification Restart Manager Smith, Nuclear Engineering Manager Swindell, Plant Support Superintendent McCarthy, Regulatory Licensing Manager Kern, Fire Protection Systems and Technology Supervisor Ebersole, Mechanical Engineer - Operations Davis, Fire Protection Engineer Abbas, Mechanical Engineer Carier, Site Licensing Manager Retzer, Fire Protection Supervisor Hatton, Fire Protection Shift Captain DeGrasse, Fire Protection System Engineer Smithson, Modifications Special Projects Manager McFall, Licensing Engineer Cuoco, Office of General Council Campbell, Plant Manager Salas, Compliance Licensing Manager Miller, guality Assurance Evaluater Crisler, Project Management Manager Anderson, Nuclear Engineering Special Projects Manager Other Or anizations
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- J Shields - Bishop, Cook, Purcell and Reynolds Lalon - Toledo Edison Co.
Roskoph - Toledo Edison Co NRC Personnel
- 'W Bearden - Resident Inspector
~Attended exit interview
t 2.
FIRE AREA BOUNDARIES The Browns Ferry Plant is divided into 25 fire areas.
Each fire area is required to be separated from other fire areas by fire barriers (walls, floors or roofs/ceiiingsj having a three hour fire rating or a rating which exceeds the maximum anticipated combustible fire loading within the areas.
The following fire areas were inspected for compliance with these requirements:
Fire Area No.
4.
8
10 1l
17
20
22
24 Desi nation UNIT 2, REACTOR BLDG UNIT I, 4KV SHUTDOWN BOARD RM-B UNIT I, 4KV SHUTDOWN BOARD RM-A UNIT 2, 4KV SHUTDOWN BOARD RM-D UNIT 2, 4KV SHUTDOWN BOARD RM-C UNIT 2, 480V SHUTDOWN BOARD RM-2A UNIT 2, 480V SHUTDOWN BOARD RM-2B UNIT 3, SHUTDOWN BOARD RM-F UNIT I, BATTERY AND BATTERY BOARD ROOM AND DC EQUIPMENT ROOM UNIT 2, BATTERY AND BATTERY BOARD ROOM AND DC EQUIPMENT ROOM UNIT 152, DIESEL GENERATOR BUILDING UNIT 3, DIESEL GENERATOR BUILDING UNIT 3, 4KV SHUTDOWN BOARD ROOMS 3EA 8I 3EB UNIT 3, 4KV SHUTDOWN BOARD ROOMS 3EC 5 3ED UNIT 3, 4KV BUS TIE BOARD ROOM These fire areas either presently meet the NRC separation requirements or will meet the requirements following completion of TVA's fire protection upgrade program which is to be completed prior to restart.
However, the walls separating the battery, battery board and DC equipment rooms for each Unit (Fire Areas 17, 18 and 19) from the control building (Fire Area 16)
do not appear to meet the required fire rating.
These walls are
gauge sheet metal panels with a resin-impregnated kraft paper honeycomb core that has been covered with 5/8" fire code type gypsum board on each side of the panels.
The combustible core of these panels reduces the fire resistance rating of the panels to an unacceptable level.
TVA has agreed to install additional layers of gypsum wall board on the corridor side of the wall panels.
This modification would increase the fire resistance rating of these walls.
The NRC inspection team determined that this modification would be acceptable.
Because of the low fuel loading, existing detection and existing suppression in the affected areas, the inspection team also determined that the actual physical modification would not have to be completed until the end of the next refueling outage for Unit 2.
TVA will, however, be required to commit to modification of the existing walls, and to propose additional compensatory measures to be maintained until the modification is completed.
The formal commitment to modify the wall and proposal of compensatory measures will be required before Unit 2 restart.
This item is identified as Unresolved Item 50-259/89-28-01, 50-260/89-28-01 and 50-296/89-28-01.
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Fire Area 2, Unit 2 Reactor Building, is divided into six fire zones for compliance with 10 CFR 50 Appendix R.
Water curtains and draft stops are utilized as a means to separate each fire zone.
Electrical and mechanical penetrations of the reactor building floors are sealed with fire rated seals.
HVAC duct penetrations through floor slabs are provided with fire dampers having at least a lk hour fire rating.
Also, additional fire detection and suppression systems are being installed within these fire zones.
A walkdown inspection of these zones indicated that the separation of each zone conforms to the description in TVA's evaluation document (Appendix G of Volume III of the Appendix R Engineering Evaluations).
The inspectors determined that all areas inspected were acceptable with the exception of the composite wall as described above.
3.
FIRE SUPPRESSION SYSTEflS During the inspection, the fire suppression systems were inspected for agreement with the descriptions in the TVA Appendix R Engineer ing Evaluations.
No discrepancies were found.
The suppression systems which protected the fire areas inspected, included a preaction sprinkler system covering most of the areas, an aqueous film forming foam (AFFF) system covering the reactor coolant pump motor generators, and the CO system covering the diesel generators and cable spreading room.
Deviations from NFPA codes had already been identified by TVA and those which were not approved by NRC staff were in the process of being corrected.
(Paragraph 11.0)
The design of the sprinkler system for 593'levation of the Unit 2 Reactor Building, as shown on drawings DCA E-2-P7171-017 and E-2-P7171-018, was reviewed.
This system will provide practically total coverage for the 593'levation and is designed to discharge a density of at least 0. 16 gpm/square foot at the most remote 1500 square feet of floor area.
The design demand for this area is approximately 590 gpm at 94 psi.
Recent tests by the licensee indicated that a water supply of 600 gpm at 120 psi was available to the system.
No areas of nonconformance to NFPA codes or NRC criteria were found in the sprinkler system design.
The licensee stated that the design of the remaining sprinkler systems are to meet the same design criteria as this system.
4.
DETECTION SYSTEt1S Fire detection systems at the plant consist of both supervised and unsupervised circuits.
Although, originally characterized as Class A
supervised circuits, TVA has amended its characterization of BFN detection circuits to a mixture of Style D (Class A) and Style B (Class B) as defined by Table 3-9. 1 of NFPA 72-1979.
The amended characterization was required by TVA's use of Walter Kidde Fire Alert CPD-1201 ionization smoke detectors and the associated detection circuit.
In the event of a fire, with the present detection system, an alarm will be sent even with a single break or single fault in the detection circuit. If the power supply circuit is lost, detection capability is also lost in all detectors downstream of the break in power supply.
However, a trouble signal will be sent for loss of power supply, the same as for a break or fault in the detection circui Upon re-examination of the circuit, TYA determined, and the staff agrees, that this type of circuit does not meet current definitions of a Style D (Class A)
detection.
However, the inspectors have concluded that TYA procedures which require immediate investigation of trouble signals and correction of any malfunction within one hour (or compensatory measures),
are adequate to ensure a level of protection approximately equivalent to a Style D (Class A) super-vised circuit.
In addition to the above described detection circuits, there are also detection circuits, alarm circuits and suppression actuation circuits which are not electrically supervised.
The unsupervised circuits are tested on a
monthly basis.
The inspectors have concluded that this is an adequate interval to insure reliability for unsupervised detection and alarm circuits.
The inspection team discussed with the licensee the lack of detection in the shutdown board rooms (Fire Areas, 4-12).
Detection in these areas is not required by either Appendix R or the staff SER (SER, NUREG-0061, dated March 1976, related to Operation of Browns Ferry, Units 1 and 2 following the March 22, 1975 Fire).
Detection would be required by Appendix A to BTP APCSB 9.5-1 if that document was applicable to BFNP.
However, BFNP is excluded.from having to comply with Appendix A to the BTP by 10 CFR 50.48.
The inspectors understand that TYA will install detection in the shutdown board rooms by the end of the next refueling outage as part of the BFN fire protection upgrade program.
5.
STATUS OF MODIFICATIONS Most of the Appendix R modifications for Unit 2 are nearly complete.
The licensee estimated the construction status for'the principle fire protection features is as follows:
MODIFICATION PERCENT COMPLETE Cable, conduit reroute or wrap Seals, for electrical raceways and mechanical fire barrier penetrations Emergency lighting Fire doors and dampers Automatic sprinkler and detection systems 85$
80K 95%
95K 70%
These modifications for Unit 2 are to be finished and documentation of inspections, tests, etc., are to be completed prior to Unit 2 restart.
The completion of these modifications will be tracked as inspector follow-up items and will be identified as follows:
(a) IFI 50-259/89-28-02, 50-260/89-28-02, 50-296/89-28-02:
Completion of cable and conduit reroute or wrap modifications.
(b) IFI 50-259/89-28-03, 50-260/89-28-03 and 50-296/89-28-03:
Completion of seals for electrical raceways and mechanical fire bar rier penetrations.
(c) IFI 50-259/89-28-04, 50-260/89-28-04 and 50-296/89-28-04:
Completion of emergency lighting installation.
(d) IFI 50-259/89-28-05, 50-260/89-28-05 and 50-296/89-28-05:
Completion of modifications to fire doors and dampers.
(e) IFI 50-259/89-28-06, 50-260/89-28-06 and 50-296/89-28-06:
Completion of modifications for automatic sprinkler and detection systems.
6.
ADMINISTRATIVE PROCEDURES The inspectors reviewed six administrative procedures which were attachments'o Procedure FPP-2, "Fire Protection Plan."
The attachments reviewed were as follows:
(a)
Attachment C - "Control of Transient Combustibles."
(b)
Attachment F - "Fire Protection Equipment and Barrier Penetration Removal from Service."
(c)
Attachment G - "Storage and Labeling of Hazardous Chemicals, Flammable or Combustible Liquids, and Compressed Gas Cylinders."
(d)
Attachment H - "Periodic Inspections and Testing of Fire Protection Systems and Equipment."
(e)
Attachment I - "Torch Cutting, Welding, Open-Flame, Grinding and Spark Producing Work Requirements and Precautions."
(f)
Attachment J - "Facility Design, Modification and Temporary Structure Requirements."
These attachments establish procedures which conform to NRC requirements and guidelines and to other regulatory requirements such as the NFPA codes.
The only discrepancy from NRC criteria identified by the inspectors was in Attachment C - "Control of Transient Combustibles."
In this attachment, fire-retardant, pressure-treated lumber was identified both as a noncombus-tible and a combustible which should be controlled.
This attachment is in the process of revision and fire-retardant, pressure-treated lumber will be categorized as a controlled combustible.
Otherwise, the procedures were determined to be acceptable.
7.
PENETRATION SEAL PROGRAM The inspectors reviewed the licensee's procedure dealing with penetration fire stops and found it acceptable.
The inspectors also selected a number of seals in the plant so that the licensee could demonstrate its program for tracking individual penetration seals.
Each seal is identified by a unique nine character identifier.
This identifier provides the unit number, building, floor elevation and direction of the seal from the viewer.
For each identifier, the licensee can search computer records and determine pertinent details for each penetration, such as the size and shape of the penetration seal and-5-
specific construction characteristics.
Also included are particular details that would affect the penetration seal design such as temperature and vibration associated with the individual penetrations.
8, B1ERGENCY LIGHTING The emergency eight hour battery lighting for the access and egress to shutdown components requiring manual actions, as shown on TVA drawings 45M400-RM-01 through RM-07, were reviewed.
A walkdown inspection was made of the lighting Units on the 593'levation of the control building and in the Unit 2 shutdown board rooms.
During this review no areas of nonconformance to 10 CFR 50 Appendix R Section III.J were found in regard to emergency lighting.
In addition, an inspection was made of the lighting unit which was added to illuminate the remote shutdown panel in Fire Area 9 on elevation 621 of the Reactor Building.
The addition of this light closes inspector follow-up item IFI 50-259/89-13-07, 50-260/89-13-07 and 50-296/89-13-07.
9.
FIRE BRIGADE DRILL The inspection team witnessed an announced but unplanned drill of the site fire brigade.
A fire was postulated in the cable-spreading room,.10-12 feet into the stacks, with an initial alarm of a smoke detector followed by a second detector which tripped the preaction valve and charged the sprinkler system with water.
The incident commander responded in about 60-90 seconds and established a
command post.
The brigade responded in about 7 minutes with six members in full gear including self contained breathing apparatus (SCBA).
The postulated fire was declared under control in about 18 minutes after the alarm was sounded.
The inspectors considered the response appropriate and timely for the assumed initial conditions of heavy smoke, limited visibility and water flowing from one open sprinkler head.
The drill demonstrated a good balance between a
conservative approach due to the poor visibility and an attack sufficiently aggressive to bring the fire under control.
k The only comment that the inspection team members had was that health physics and security personnel who participated in the drill were not at the debriefing session.
The licensee did state that any comments in regard to performance of health physics or security personnel would be passed on to them.
10.
GENERIC LETTER 86-10 EVALUATIONS The inspectors reviewed engineering evaluations made in accordance with the provisions of Section 4, "Fire Area Boundaries" to Enclosure 1,
" Interpretations of Appendix R" to Generic'Letter 86-10.
These provisions require that a licensee retain, for NRC audit, evaluations made for openings or penetrations in fire area boundaries.
The licensee presented two evaluations as examples of GL 86-10 engineering evaluations.
These were an evaluation of unducted ventilation openings and an evaluation of embedded conduits.
The inspectors concluded that the licensee's recordkeeping in regard to Section 4 of Enclosure 1 of Generic Letter 86-10 was satisfactory.
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11.
NFPA CODE DEVIATION COMMITMENTS At the request of the staff, TVA submitted a list of deviations to NFPA codes on August 3, 1988 (Gridley to USNRC).
TVA concentrated their review in four specific areas:
(a)
Sprinkler, Mater Spray, and Foam-Water Sprinkler Systems (NFPA 13, NFPA 15 and NFPA 16A).
(b)
Carbon Dioxide Systems (NFPA 12).
(c)
Fire Protection Water Supply System (NFPA 20, NFPA 24, and NFPA 14)
(d)
Fire Detection Systems (NFPA 72D and NFPA 72E).
The NRC staff evaluated TVA's analysis of NFPA code deviations.and made a
determination as to their individual acceptability.
Some of the deviations were accepted contingent upon TVA performing certain analyses or making procedures available for inspection.
The staff position was stated in S. Black's letter of December 14, 1988 to 0. Kingsley.
The licensee listed commitments required for NRC approval of the code devi-ations by letter of February, 3, 1989 (Gridley to USNRC).
Of the five commit-ments made, four of them required NRC review at the Appendix R audit.
These four commitments were:
(a)
To provide a flow test of the diesel driven fire pump to verify that the strainer is adequate for two hours of operation without backwashing.
(b)
To revise the current surveillance instruction used to ensure that non-indicating sectional valves are open.
(c)
To perform a flow test of all hose racks provided with greater than 100 feet of hose.
(e)
To make available Operating Instruction 18 regarding fuel oil transfer to the diesel generators.
All of the above listed tests and instructions were reviewed by the team and found to be acceptable.
TVA s fifth commitment, which was to add air supervision to the Reactor Building preaction sprinkler system prior to restart will be verified for completion as part of IFI 50-259/89-28-06, 50-260/89-28-06 and 50-296/89-28-06, completion of modification for automatic sprinkler and detection systems.
12.
NRC CONCERNS REGARDING 1987 UNIT 2 DRYWELL FIRE Two items identified during the 1987 Drywell Fire Investigation involved the lack of prefire plans for the drywell and procedures to identify the need to secure electrical power for temporary equipment within the drywell in the case of fir The licensee has issued prefir e plans RXDW1, RXDW2 and RXDW3 covering all sections of each drywell.
These prefire plans follow the same format as the plans for the other plant fire areas and meet current NRC guidelines.
Procedure FPP-3, "Fire Emergency Response Organization and Prefire P1ans,"
Section 5.7.1 assigns&he incident commander the responsibility of de-energizing equipment in the fire area to maximize the safety of personnel and the protection of the plant.
This addresses the NRC concern of assuring that electrical power to temporary power supplies such as welding equipment will be secured in the event of fire.
13.
BFNP PROCEDURES FOR PREVENTING FIRES IN URETHANE EXPANSION GAP MATERIAL B W
EN HE DRYW LL AND THE BI L ICAL HI LD During removal of a mechanical penetration into the drywell at Dresden, hot slag from the cutting operation fell down the annulus space between the penetration sleeve and the mechanical penetration itself.
The hot slag ignited the urethane and fiberglass material that provided space for thermal expansion of the drywell during plant oper ation.
Following that fire, all licensees with similar GE plant designs were asked to review their operation so as to minimize the chance of a similar occurrence.
There is one major difference between the Browns Ferry and that lessens the likelihood of a similar fire.at BFNP.
At penetrations enter the drywell at an angle about 45'bove This angle allowed the hot slag an easy access down to the gap material.
At BFNP, the penetrations enter the drywell Dresde~
designs Dresden many of the the horizontal.
combustible expansion on the horizontal.
The inspection team also reviewed the licensee's procedure for torch cutting, welding and other open flame and hot metal working operations.
The inspectors concluded that these procedures are comprehensive and adequate to prevent a
fire similar to that which occurred in the Dresden expansion gap material.
In addition, the inspectors believe that the procedures are adequate to minimize the likelihood of fire being caused by such operation in other locations in the plant.
14.
EXIT INTERVIEW The inspection scope and findings were summarized on July 21, 1989 with those persons indicated in section 1.0 above.
The licensee acknowledged the follow-ing inspection findings:
One unresolved item was identified:
50-259/89-28-01, 50-260/89-28-01 and 50-296/89-28-01:
Potential failure to meet Section III.G.3 of 10 CFR 50 Appendix R, Paragraph Five inspector follow-up items were identified:
50-259/89-28-02, 50-260 89-28-02 and 50-296 89 50-259/89-28-04, 50-260/89-28-04 and 50-296/89-28-04:
Completion of emergency lighting installation, Paragraph 5.0.
59-259/89-28-05, 50-260/89-28-05 and 50-296/89-28-05:
Completion of modifications to fire doors and dampers, Paragraph 5.0.
50-259/89-28-06, 50-260/89-28-06 and 50-296/89-28-06:
Completion of modifications for automatic sprinkler and detection systems, Paragraph 5.0.
One inspector follow-up item from a previous inspection was closed.
IFI 50-259/89-13-07, 50-260/89-13-07 and 50-296/89-13-07, Installation of an additional emergency light on the remote shutdown panel, Paragraph 8.0.
/
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-28-02:
Completion of cable and conduit reroute or wrap modifications, Paragraph 5.0.
50-259/89-28-03, 50-260/89-28-03 and 50-296/89-28-03:
Completion of seals for electrical raceways and mechanical fire barrier penetrations, Paragraph 5.0.