ML18036A481
| ML18036A481 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 12/23/1991 |
| From: | Zeringue O TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9201060056 | |
| Download: ML18036A481 (11) | |
Text
ACCELERATED DISTRIBUTION DEMONSTPATION SYSTEM REGULATORY INFORMATION DISTRIBUTION SYSTEM (RIDS)
CCESSION NBR:9201060056 DOC.DATE: 91/12/23 NOTARIZED: NO FACIL:50-259 Browns Ferry Nuclear Power Station, Unit 1, Tennessee 50-260 Browns Ferry Nuclear Power Station, Unit 2, Tennessee 50-296 Browns Ferry Nuclear Power Station, Unit 3, Tennessee AUTH.NAME AUTHOR AFFILIATION ZERINGUE,O.J.
Tennessee Valley Authority RECIP.NAME RECIPIENT AFFILIATION Document Control Branch (Document Control Desk)
DOCKET 05000259 05000260 05000296
SUBJECT:
Responds to NRC 911127 ltr re violations noted in Insp Repts 50-259/91-40,50-260/91-40 E 50-296/91-40 on 911017-1115.
Corrective actions:plant design change implemented to include automatic opening of exciter field breaker.
DISTRIBUTION CODE:
IE01D COPIES RECEIVED:LTR ENCL J SIZE:
TITLE: General (50 Dkt)-Insp Rept/Notice of Violation Response NOTES:
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RECIPIENT ID CODE/NAME HEBDON,F WILLIAMS,J.
INTERNAL: ACRS AEOD/DEIIB t
DEDRO NRR MORISSEAUiD NRR/DLPQ/LPEB10 NRR/DREP/PEPB9H NRR/PMAS/ILRB1.
OE DI~R~~~~
REG ILE 02
~w EXTERNAL: EG&G B YCE,J.H.
NSIC COPIES LTTR ENCL 1
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1 RECIPIENT ID CODE/NAME ROSS,T.
AEOD AEOD/DSP/TPAB NRR HARBUCK,C.
NRR/DLPQ/LHFBPT NRR/DOEA/OEAB NRR/DST/DIR SE2 NUDOCS-ABSTRACT OGC/HDS3 RGN2 FILE 01 NRC PDR COPIES LTTR ENCL 1
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D NOTE TO ALL"RIDS" RECIPIENTS:
PLEASE HELP US TO REDUCE WASTE! CONTACT THE DOCUMENT CONTROL DESK, ROOM P 1-37 (EXT. 20079) TO ELIMINATEYOUR NAME FROM DISTRIBUTION LISTS FOR DOCUMENTS YOU DON'T NEED!
TAL NUMBER OF COPIES REQUIRED:
LTTR 25 ENCL 25 A
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Tennessee Vatrey Authority, Post Office Box 2000. Decatur. A!auama 35609 December 23r 1991 O. J. 'Ike'eringue Vice Pres Oen:, Browns Fe:~y Operations U.S. Nuclear Regulatory Commission ATTN:
Document Control Desk Washington, D.C.
20555 Gentlemen:
In the Matter of Tennessee Valley Authority Docket Nos.
50-259 50-260 50-296 BROWNS FERRY NUCLEAR PLANT (BFN) NRC INSPECTION REPORT 50-259,
- 260, 296/91-40 REPLY TO NOTICE OF VIOLATION (NOV)
This letter provides TVA' reply to the NOV transmitted by letter from B. A. Wilson to D. A. Nauman dated November 27, 1991.
In this letter, NRC cited TVA with a violation involving three examples of failure to follow procedures.
Enclosure 1 to this letter is TVA's "Reply to the Notice of Violation" (10 CFR 2.201).
If you have any questions regarding this response, please telephone Raul R. Baron at (205) 729-7570.
Sincerely, h
0 J. Zeringue Enclosure cc:
See page 2
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ENCLOSURE 1 Tennessee Valley Authority Browns Ferry Nuclear Plant (BFN)
Reply to Notice of Violation (NOV)
Inspection Report Number
~~LAT~IN "During the Nuclear Regulatory Commission (NRC) inspection conducted on October 17 November 15,
- 1991, a violation of NRC requirements was identified.
The violation with three examples was for failure to follow procedures for control of electrical systems.
In accordance with the "General Statement of Policy and Procedure for NRC Enforcement Actions," 10 CFR Part 2, Appendix C (1991),
the violation is listed below:
Technical Specification Section 6.8.1, Procedures, requires that written procedures shall be established, implemented, and maintained covering the activities recommended in Appendix A of Regulatory Guide 1.33, Revision 2, February 1978.
Appendix A of Regulatory Guide 1.33 includes administrative procedures for equipment control and general operating procedures.
Contrary to the above, these requirements were not met for the following three examples:
1.
Operating Instruction 47, Turbine Generator
- System, requires that the generator exciter field breaker be opened after opening the generator output breaker.
On October 18, 1991, during a controlled plant shutdown, the exciter field breaker was not opened which caused a reverse power relay actuation causing an electrical transient.
This resulted in the operators tripping the reactor due to the number of unexpected equipment responses.
2.
Site Directors Standard Practice 14.9, Equipment Clearance Procedure, requires for components which are not uniquely identified, that tags will identify specifically as possible the location of the tagged components.
On September 22,
- 1991, Hold Order 0-91-657 did not specify fuse unique identification numbers nor specify the location of fuses in the breaker compartment.
This resulted in wrong fuses being pulled and transfer of the 4160 volt shutdown board from the normal power supply to the alternate supply.
U.S. Nuclear Regulatory Commission December 23'991 cc (Enclosure):
NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens,'labama 35611 Mr. Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20852 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
0 0
Enclosure 1
Page 3 of 5 At the time this clearance was developed, TVA was in the process of implementing the fuse labeling program at BFN.
This program involves providing UNIDs for class 1E fuses, incorporating these UNIDs in the controlled plant drawings, and labeling the affected fuses in the plant.
Because the program is not fully implemented, operators had not been directed to use the fuse UNIDs when preparing clearances.
At the time of this event, an equipment clearance was prepared to support the annual maintenance inspection of the 1B diesel generator.
To establish the boundary for this clearance the line side potential transformer (PT) fuse for breaker 1822, which is located in compartment 3 of 4kV Shutdown Board B, was required to be pulled.
The tag that was prepared by Operations personnel to pull this fuse specified "BKR 1822 Line Side PT fuse 4 kV S/D Bd B Compt 3."
This tag not only identified the fuse but also provided the location of the fuse.
After the operator completed preparing the clearance, AUOs were assigned to pull this fuse and hang the tag which identified that portion of the clearance boundary.
When the AUOs entered the shutdown board room to locate 4kV Shutdown Board B, compartment 3, they discovered that'compartment 3 has two compartment doors:
one on the front of the compartment labeled "AUXILIARYPANEL" and one on the byck of the compartment labeled "4160V SHUTDOWN BUS 1."
This configuration differs from most breaker compartments at BFN since most compartments have only one compartment door.
Since the AUOs were not trained to recognize the significance of the word "BUS" in the label, and a second label on the rear compartment door contained the words "PT Compartment,"
the AUOs incorrectly concluded that the rear compartment housed the fuses to be pulled.
As a result, the AUOs opened the wrong compartment door which resulted in the equipment actuations specified in the violation. It should be noted that these equipment actuations occurred when the compartment door was opened, which due to the configuration of the door electrically disconnected the fuses; however, at no time were fuses physically pulled from their fuse holders.
In addition, the description provided on this clearance had been used previously by other AUOs to successfully pull these fuses.
At the time of this event, TVA's procedure for installing plant labels at
- BFN, SDSP 12.6, t
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required that Operations be responsible for preparing labels and labeling the plant.
Furthermore, the procedure stated that following a plant modification "[Operations]
will then fabricate/procure and install tags, labels, and nameplates."
In this event, Operations personnel maintained their responsibility for preparing and placing labels in the plant.
It should be noted that SDSP 12.6 was superceded by Site Standard Practice 12.53, t
t, on August 4, 1991.
Therefore, SDSP 12.6 was the procedure in use during this event, not SSP 12.53 as described in the NOV.
Enclosure 1
Page 2 of 5 3.
Site Standard Practice 12.53, Component Labeling Signs and Operator Aids, requires that Operations be responsible for preparing and hanging labels as modifications are completed.
Design Change Notice W6839B, Modification for Reroute/Replace/Retag Electrical Cables, did not adequately address the removal of spared or deleted labels involving the 2B-3, Drywell Blower.
The inspector identified on September 25, 1991, a power supply breaker identification label for drywell blower 2B-3 that was on two different electrical boards.
This is a Severity Level IV Violation (Supplement I) applicable to all three units."
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a.
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This violation was the result of a failure to follow procedures.
Specifically, Operating Instruction (OI)-47, G
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requires that the generator exiter field breaker be opened after a manual turbine generator shutdown.
In this event, BFN Unit 2 was undergoing a controlled shutdown.
During the shutdown, the turbine generator was manually tripped due to high vibration.
Following the manual turbine trip, plant personnel failed to follow the requirements of OI-47 and did not open the generator exciter field breaker.
Subsequently, during the generator coast down with the exciter energized, the generator continued to produce voltage at a declining frequency.
This resulted in an inadvertent actuation of the reverse power relay.
Additional unexpected equipment responses led Operations to conservatively initiate a manual reactor scram.
b.
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This event occurred when assistant unit operators (AUO) hanging tags in support of an equipment clearance opened the incorrect compartment door on 4kV Shutdown Board B, resulting in unplanned equipment actuations.
The AUOs believed that the fuses which they were required to pull in support of the clearance were located inside this compartment.
TVA's procedure for issuing equipment clearances at BFN, Site Director Standard Practice (SDSP) 14.9,
, requires that when clearances are being developed, the equipment or component being tagged will be entered on the clearance sheet.
Furthermore, the procedure states that "[f]or components not uniquely identified, the clearance sheet and hold notice tags will identify as specifically as possible the location of the tagged components."
Enclosure 1
Page 4 of 5 Prior to BFN Unit 2 restart, Design Change Notice (DCN) H2242 was issued to modify the power supply breakers associated with the drywell blowers.
A part of this DCN included modifying the 2B-3 drywell blower power supply breakers by placing the breaker in compartment 8A of 480V reactor motor operated valve (RMOV) board 2A in series with the existing 2B-3 power supply breaker.
However, prior to performing this portion of the modification, a field design change notice was issued which deleted this work.
Therefore, a labeling request was not issued to modify the existing label on compartment 8A.
Subsequently, DCN-W6839 was issued which addressed drywell blower 2B-3 and interchanged its supply breaker with another drywell blower supply breaker.
The work associated with DCN-W6839 did not modify the 8A compartment of 480V RMOV board 2A and therefore did not address, nor should it have addressed, the labeling of this compartment.
It should be noted, compartment 8A of 480V RMOV board 2A remains a spare compartment as it was during this event.
On March 18, 1991, Operations support personnel determined that work plans associated with DCN-H2242 were complete but inappropriately concluded that the necessary plant label requests were not provided.
Accordingly, Operations support personnel assembled the necessary supporting documentation to provide plant labels.
- However, the individual assembling this information did not properly research the documentation.
This resulted in the label associated with the 2B-3 drywell blower power supply being placed in the plant even though the modification was not performed.
2.
Corrective Ste s Taken and Results Achieved a.
Generator Breaker Operations personnel will receive live-time training on this event.
BFN has implemented a plant design change to include automatic opening of the exciter field breaker when the turbine generator is tripped.
It should be noted that these corrective actions were previously transmitted to NRC by Licensee Event Report 50-260/91018, dated November 18, 1991.
Therefore no additi'onal commitments are being made in this reply.
b.
Identification of Com onents on E ui ment Clearances Because of the unique configuration of the 4kV shutdown boards, a
directive has been issued by the operations superintendent which requires that an assistant shift operations supervisor accompany AUOs when tagging components on these boards.
Signs have been placed on the 4kV shutdown board compartments which contain PT fuses in front and rear compartments to inform personnel of this plant configuration.
(4
Enclosure 1
Page 5 of 5 c.
gggmLi,n Affected personnel have been counseled on this event and on the importance of ensuring complete reviews of plant documentation when preparing plant label requests.
The incorrect label in the plant has been replaced.
3.
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PigQgttgng t
v th On December ll, 1991, the BFN plant manager issued a bulletin to all site personnel addressing management's expectations regarding procedural adherence.
This bulletin discussed the need for each employee to perform work completely, correctly, and safely.
The bulletin reiterated the importance of stopping work if a procedure, instruction, or method of doing work is cumbersome, incorrect, or can be done better.
Furthermore, the bulletin reemphasized BFN's seven-step self-checking program which is deigned to improve procedural adherence and operational performance by ensuring any action taken is the correct one and verifying that the expected results are achieved.
4 a.
TVA considers that full compliance will be achieved for this example upon completion of the Operations personnel live-time training.
This training was previously committed to be complete by January 17, 1992.
b.
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TVA considers that full compliance has been achieved for this example.
co TVA considers that full compliance has been achieved for this example.