05000255/LER-1995-004-01, :on 950714,determined That Redundant DG Circuits Not Separated Per App R Due to Insufficient App R Program Documentation.Hourly Fire Tour Established in EDG 1-1 Room & Review of LERs for App R Completed
| ML18064A863 | |
| Person / Time | |
|---|---|
| Site: | Palisades, Diablo Canyon  |
| Issue date: | 08/14/1995 |
| From: | Roberts W CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.), EWTCPG |
| To: | |
| Shared Package | |
| ML18064A862 | List: |
| References | |
| LER-95-004-01, LER-95-6-1, NUDOCS 9508210076 | |
| Download: ML18064A863 (7) | |
text
. NRC F0rm 388 (8-831 U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /86 LICENSEE EVENT REPORT (LERI FACILITY NAME 111 DOCKET NUMBER 121 PAGE (31 Palisades Plant 0
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5 TITLE 141 LICENSEE EVENT REPORT 86-004 *REDUNDANT DIESEL GENERATOR CIRCUITS NOT SEPARATED PEJI APPENDIX R EVENT DATE 161 REPORT DATE (81 OTHER FACILITIES INVOLVED 181 REVISION FACILITY NAMES MONTH DAY YEAR YEAR NUMBER MONTH DAY YEAR.
N/A 0 7 1 4 9 5 9 5 0 0 4 00081495 N/A THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR I: fCheclcOM or more of the following) (111 OPERATING MODE 181 N
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William L. Roberts 20.406(*)(1 )(iii) 20.406(*111 )(iv) 20.406lell11M LICENSEE CONTACT FOR THIS LER (121 60.73(*1121lviiillAJ
- 60. 7 3l*ll211viiillBI 60.73(*1121b<I AREA CODE below end in Text, TELEPHONE NUMBER 6
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COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (131 1-~-....~~--~~~~~---..~~~~~---.~~~---.
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MAN UFA C -
REPORTABLE
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SYSTEM COMPONENT TURER TO NPRDS SUPPLEMENTAL REPORT EXPECTED 1141 YES l/f...._ _.,. EXPECTED SUBMISSION DA TEl x NO ABSTRACT Wmh to 1400 _.
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CAUSE
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TUR ER MONTH EXPECTED SUBMISSION DATE (151 REPORTABLE TO NPRDS DAY 3
YEAR On July 14, 1995 at 1 :00 p.m. it was determined that emergency diesel generator (EOG) 1-2 power and control circuits do not meet 10 CFR 50, Appendix R, Section 111.G requirements. The power and* control circuits for the 1-2 EOG are routed in the air inta.ke plenum for EOG 1-1. The EOG 1-1 intake air plenum does not have a qualified fire barrier separating it from the EOG 1-1 room. Hourly fire tours were initiated immediately in the diesel generator 1-1 room adjacent to the intake air plenum and will continue until a resolution is identified and implemented.
This condition was identified as part of the Palisades Plant Appendix R Enhancement Program. The Appendix R Enhancement Program was checking cable routing, reassigning fire areas and verifying that complete analysis exists for each fire area. Completion of the Appendix R Enhancement Program will assure that any additional areas of Appendix R cable routing non-compliance are identified.
9508210076 950814 PDR ADOCK 05000255 S
NRC Form 388A (9-83)
FACILITY NAME 111
- Palisades Plant
- Event Description LICENSEE EVENT REPORT (LER) TEXT CONTIN.UATION DOCKET NUMBER 121 LER NUMBER 131 SEQUENTIAL YEAR NUMBER U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /86 REVISION NUMBER PAGE 141 0
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5 On July 14, 1995, the plant was in cold shutdown for a r~fueling outage. As a result of on-going reviews being completed as part of the plant Appendix R enhancement program, it was
- determined that the emergency diesel generator (EOG) 1-2 power and control circuits to the safety related "D" bus (EA-12), were routed in the intake air plenum for EOG 1-1. The intake air plenum for EOG 1-1 does not have a qualified fire barrier separating it from the EOG 1-1 room
. per 10 CFR 50, Appendix R, Section 111.G. The intake air plenum was not classified as a fire area and the fire barrier that separates the EOG 1-1 room from this* plenum area is not fire rated.
The intake air duct work and penetrations also are not fire rated.
Therefore a single fire inside the EOG 1-1 fire area could potentially disable both diesel generators.
An hourly fire tour was initiated for the EOG 1-1 fire area, therefore compensating for the lack.
. of a fire r~ted barrier to the air intake plenum room. A portion of the EOG 1-1 north wall is considered inoperable (with an hourly fire watch to compensate) until a resolution to the lack of proper circuit separation is identified and implemented.
This event is reportable in accordance with 10 CFR 50. 73(a)(2)(ii)(8) as a condition outside the
- design basis of the plant.
CAUSE OF THE EVENT
- 1. Appendix R program documentation was insufficient to demonstrate regulatory compliance o its own merit. The original Appendix R reviews also did not properly.address this cable configuration.
- 2. Prior to the time the Appendix R enhancement program was established, there was lack of ari adequate self assessment program as pointed out by the 1994 independent assessment. *
(This is no longer an issue.)
- ANALYSIS OF THE EYENT
. In June 1994 an independent assessment of the Palisades Appendix R Program was performed by Engineering Planning and Management, Inc. (EPM), a firm specializing in nuclear plant fire
- protection. The assessment was commissioned by plant management because of concerns over the state of compliance to the requirements of 10 CFR 50, Appendix R. The audit involved a comprehensive evaJuation of the Palisades Appendix R Program.
The assessment was. performed from the perspective of providing demonstrable compliance to regulatory requirements from the existing Appendix R documentation. On this basis,
- conclusions were made based on the existence of auditable documentation.
.19-83).
U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3160-0104 EXPIRES: 8/31/86 LICENSEE EVENT REPORT (LERI TEXT CONTINUATION.
FACILITY NAME (1)
Palisades Plant DOCKET NUMBER (2)
YEAR LER NUMBER (3)
SEQUENTIAL NUMBER REVISION NUMBER PAGE (41 0
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5 The overall conclusion of the as$essment team was that the existing Appendix R documentation was insufficient in certain areas to demonstrate regulatory compliance on its own merit.
Analyses were not well documented and in many cases were not being maintained current with changes to the plant. The team further concluded that the Appendix R Program was not being given the management priority requir<<!d to effectively establish and maintain the program in today's regulatory environment. Nume.rous weaknesses identified during the assessment were recurring problems from previous NRC and consultant audits. In summary, the compliance
. status of some aspects of the Appendix R program were not readily verifiable based on a lack of available and auditable documentation.
As a result of the June 1994 assessment, existing plans in place to upgrade the program were greatly accelerated." Additional management attention was also placed on ensuring timely identification and resolution of Appendix R deficiencies.
The ongoing Appendix R enhancement program is systematically performing a complete circuit analysis, performing circuit walkdowns and reassigning fire zones to validate and re-baseline earlier Appendix R work. It was this Appendix R enhancement program that identified this condition and other less significant issues. Until the Appendix R enhancement program is completed, Palisades Plant may identify additional deficiencies.
- Past Operability The hourly fire tour in the EOG 1-1 room was established as part of the initiation of the corrective action document. An overview drawing of the fire area in question is shown as.
For the period prior to July 14, 1995, the barrier as a whole cannot be considered operable for the following reasons:
- Although the air plenum ducts were inspected until sometime in 1994, the non-fire rated recirculation damper (D-25) was not inspected as part of the fire barrier or penetration seal surveillance program. Therefore, no doqumentation exists on past operability of this
. damper as a fire barrier.
- Prior to 1993 damper D-25 was used as a recirculation damper and was inspected for operation yearly. In 1993 it was determined that the damper was not needed and was
- disabled closed. In the past (Pre-1993) a fire could have caused the damper to spuriously open, or it may have been open when the fire occurred and could have failed open, thus allowing hot gases to enter the air plenum and damage the redundant diesel power and
. control circuits. The potential spurious opening or failed open conditions are outside the design basis for the damper as a recirculation device. Therefore, the damper as a ventilation system component was operable, but as a component in a fire barrier was inoperable.
NRC Form 388A 19-83)
~. *FACILITY NAME {1)
Palisades Plant
- LICENSEE EVENT REPORT (LERI TEXT CONTINUATION DOCKET NUMBER 121 YEAR LER NUMBER (3)
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- While numerous hourly fire tours have been established for the diesel generator 1 -1 and 1 -2 rooms throughout the past years, there has not been a continuous hourly fire tour documented in historical records.
Consequently, prior to July 14, 1995,' when the hourly fire tour was established.in the EDG 1-1 room, the plant operated with an inoperable fire barrier (non-rated fire wall) separating the EDG 1-1 room (Room 1 16) from the EDG 1-1 air plenum room (Room 148) where the redundant EDG 1-2 power and control circuits are located. This condition is outside the plant design basis required by 10 CFR 50, Appendix R, Section 111.G.
. SAFETY SIGNIFICANCE Substantial protection is provided by the existing wall and ventilation penetrations between the 1-1 EOG room and air plenum even though they were not rated or inspected as a 3-hour fire barrier. The air plenum reinforced concrete wall is approximately 12 inches thick and a portion of the air plenum floor that provides.separation from the EOG 1-1 room is approximately 9-1 /2 inches thick. These portions of the barrier are acceptable as a 3-hour fire rated barrier as they exceed the 5-1 /2 inch thickness required for 3-hour rating (per NFPA Fire Protection Handbook, 17th Edition, Figure 6-5G). The unrated ventilation air intake ductwork
- and recirculation damper in this wall are substantial steel enclosures that prevent direct impingement of smoke and* hot gases on the circuits in the plenum. The two air intake ducts are opened at each end; one end in the EOG 1-1 room and the other end in the air plenum.
room. A plant walkdown determined that the horizontal distance between the openings at each end of the duct is equal to or greater than 20 feet thus providing a degree of separation between the two rooms. The air recirculation damper is currently failed closed. such that it
- provides a passive fire stop configuration to limit the spread of smoke and hot gases~ The EOG 1-1 room has a full area wet* pipe sprinkler system which will greatly limit the intensity of a postulated fire. Water flow alarms which annunciate in the Control Room will provide notification of any fire thus initiating alarm respons~ procedures which result in a fully trained fire brigad*e response. In addition, operations and security personnel inspect these areas on a frequent basis as a normal course of business. The fire loading in EOG 1-1 room, excluding the lube oil and fuel oil located. in substantial metal enclosures, is light. The fire loading in the EOG 1-1 air plenum room is negligible as no exposed combustibles were identified in a plant walkdown. All of these factors help ensure that a realistic fire in the EOG 1~1 room would* not likely propagate into the air plenum room and affect redundant safe shutdown circuits. We therefore conclude that the safety significance of this design deficiency is low.
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NRC Form 388A 19-831 FACILITY NAME 111 Palisades Plant LICENSEE EVENT REPORT (LERI TEXT CONTINUATION DOCKET NUMBER 12)
YEAR LER NUMBER 131 SEQUENTIAL NUMBER U.S. NUCLEAR REGULATORY COMMISSION APPROVED OMB NO. 3160-0104 EXPIRES: 8/31 /86 REVISION.
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CORRECTIVE ACTION
Corrective Actions Taken and Results Achieved An hourly fire tour was established in the EOG 1-1 room to compensate for the lack of fire rated barriers to the air intake plenum room.
A review of the Licensing Event Reports for Appendix R was completed and did no_t indicate a new. trend or common failure mechanism.
Corrective Actions to Avoid Recurrence A. Provide a resolution for the lack of proper Appendix R circuit separation between the EOG 1-2 power and control circuits routed in the air intake plenum to EOG 1-1 room.
A rigorous evaluation of the as-built configuration is underway. This evaluation will determine the adequacy of the existing fire barrier (EOG 1-1 air plenum) to protect* the EOG 1-2 circuits. It will also identify other potenti_al solutions to this non-compliant condition.
B. Maintain an hourly fire tour for diesel generator room 116 until a permanent resolution is
- provided for Appendix R circuit separation between the EOG 1-2 power and control circuit routed in the air intake plenum to EOG 1-1 room.
C. The ongoing Appendix R enhancement program is systematically performing a complete circuit analysis, performing circuit walkdowns and reassigning fire zones to validate and re baseline.earlier Appendix R work. Completion of the Appendix R Enhancement Program will assure that any additional areas of Appendix R cable routing non-compliance are identified. The Appendix R Enhancement Program* is being implemented by the Palisades.
Performance Enhancement Program, NECQ Department Master Action Plan (Item 3.3.5).
ADDITIONAL INFORMATION
LEA 92-028 identified that the EDG's room cooling fan power cable configurations did not* meet
- the Appendix R cable separation criteria.
DIG 1-2.
AIR INLET PLENU DIG 1-2 ROOM
- - ATTACHMENT s*
CONDUITS X1875,X1876,X1877 (POWER CABLES FOR EA-12l -
FAN INLET DIG 1-1 AIR INLET PLENUM ECTION 'A-A' DIG f-1 ROOM FAN INLET
ATTACHMENT B D
/AIR RECIRCULATION DAMPER.
t---....;__-- -
DOOR (EX In DIG 1-1 ROOM SECTION 'A-A' DOOR DAY TANK ROOMr 2..