ML20090H100
| ML20090H100 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 03/06/1992 |
| From: | Zeringue O TENNESSEE VALLEY AUTHORITY |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 9203130265 | |
| Download: ML20090H100 (12) | |
Text
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.u.s, U.S. Nuclear Regulatory Commission ATTH:
Document Control Desk Washtugton, D.C.
20555 centlement In the Matter of Tennessee Valley Authority
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Docket Nos. 50-259 PLAN FOR UNITS 1 BROWNS FERRY talf' EAR PLANT (BFN 50 29f>
JD 3 CABLE INSTALLATION ISSUES INCLUDING SEPARATIONS E
E0ference:
TVA letter dated May 10, 1991, Action Pl Concerns Related to Unita 1 and 3 Cabl an to Disposition including Cable Separations e Installation Issues This letter provides additionni informati action plan that van described in the refon concerning TVA's corrective the referenced letter that confirmator erenced letter. TVA stated in doring Unit 2 recovery efforts.BFN Unita 1 and 3 to confirm adeq a
ation practices as found Also, to confirm the validity of data ito the walkdovm perform nit 2 installation practices.
cable database.would be performed to verify cable attribut n TVA's cable database, valkdowns The fc11oving information is included in Ees for a saudom sample o this letter:
nclosure 1 ts 1.
Selectivn criteria for inclusion of cabl es in valkdowns, 2.
A discussion of the walkdown attributes a d n
methodologies 3
database validation, and. Methodology for the BFN consolidated cabl e routing system (CCRS) 4 System and voltage level distribution of the adequacy of the random sample the sample to demonstrate This information was discussed with Joseph Wi December 17, 1991 by teleconference lliams and Frank Ashe on 9203130265 920306 PDR ADOCK 05000259 p
\\
g U.S. Nuclear Regulatory Commission IINSO6155'/
Walkdowns and other actions to resolve installation issues are in progress at BFN Unit 3.
The results of the walkdowns will be discussed in a final report on the resolution of cable installation issues. The report vill be cimilar to the Cable Issues Walkdown and Summary Reports issued for BfN Unit 2 and tratsmitted to NRC by TVA letter dated June 19, 1989 and the Electrical Cable Separations Report transmitted by letter dated January 6,1989. The report for Unit 3 vill be submitted prior to restart of Unit 3.
The Unit I report vill be submitted prior to Unit i restart.
Procedures cited in Enclosure 1 are available for review at TVA's Rockville, Maryland offices. A summary of the connitment contained in this letter is provided as Enclosure 2.
Please refer any questions concerning this submittal to J. E. McCarthy, Restart 1,1 censing Manager, at (205) 729-2)03.
Sincerely,
} l0 f!
O YYWb 0./J. Zetingue J
Enclosures cc (Enclosures):
NRC Resident Inspector Browns Ferry Nuclear Plant Route 12, Box 637 Athens, Alabama 35611 Mr. Thierry M. Ross, Project Manager U.S. Nuclear Regulatory Commission One White Flint, North 11555 Rockville Pike Rockville, Maryland 20B52 Mr. B. A. Wilson, Project Chief U.S. Nuclear Regulatory Commission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323
ENCI.OSUREI ADDITIONAL INI ORMATION CONCERNING IAl N UNITS 1 AND 3 CAllLE INSTALLATION ISSUES CORRECTIVE ACTION PLAN 1.0 Issues recuirina confirmatory walkdown 1.1 Selection criteria for issues recuirina confirratory valkf.iED As stated in TVA's May 10, 1991 letter, TVA is performing confirmatory walkdowns as part of the resolution of sidewall pressure, jaruming, pulling through 90* condulets, mid-run flexible conduits, ht:6 pullby issues for BFN Units 1 and 3.
The condition of installed enL3es observed during Unit 2 recovery efforts was attributed to good installation practices at BFN.
This was part of the basis for establishing the acceptability of installed cables for Unit 2 for thesu issues. The purpose of the confirmatory walkdowns is tt verify that good installation practices, as found on Unit 2, were used for DFN Units 1 and 3.
The criteria for selecting cables for inclusion in the confirmatory walkdown and the confirmatory walkdown methodology is the same as was used for Unit 2.
t The selection criteria for inclusion in the confirmatory walkdowns is discussed below for these issues. Where Unit 3 activities are specifically discussod, the planned approach for Unit 1 is the same.
1.1.1 Selection criteria for sidewall pressure A list of BFN Unit 3 conduits, which include site #1/0 AWG and larger safety related cables, was prepared.
These larger cable sizes were chosen since the mechanical pulling devices generally used to install these cables would have resulted in increasad sidewall pressure on the cables during installations.
Con.tuits less than 20 fent in length were not considered since tho pulling forces applied to these short lengths would be small und do not warrant study.
Safety-related conduite longer than 20 feet were evaluated during a preliminary walkdown in an effort to identify the degree of conduit bends, and the types of fittings installed.
After these preliminary walkdowns, the conduits with the longest runs and those containing the most degree of bends were selected for inspection by industry experte during the confirmatory walkdown.
1.1.2 Selection criteria for walkdown for jamming The review for this issue for Unit 3 was limited to safety-related V4 and V5 cables, size #10 AWG and larger installed in conduito.
The list of these cables and associated conduits was prepared from consolidated cable routing system (CCRS).
The ratio of the inside diameter of a conduit (D) to the cable diameter (d) was determined from the database. Conduits equal to or greater then twenty feet long containing three single conductor cables with a D/d ratio between 2.8 and 3.1 have the_ potential of cable jamming. These conduits were reviewed during the preliminary walkdown.
ENCLOSURE 1 ADDITIONAL INFORMATION CONCERNING IlFN UNITS 1 AND 3 CAllLE INSTALLATION ISSUES CORREC flVE ACTION PLAN Configurations with D/d ratio in the critical range, which are long runs (to preclude hand pulls) and have many conduit bends and cable access points (i.e.,
junction boxes, pull boxes, and conduit fittings), were listed for confirmatory walkdown by industry experts. The experts inspected those junction / pull boxes or conduit fittings for cable damage that could be caused by janning during installation.
1.1.3 Selection criteria for walkdown for pulling through 90 degree condulete and mid-run flexible conduits For Unit 3, a preliminary walkdown of the Reactor, Control, and Diesel Generator buildings was perf ormed to locate aaf ety-related mid-run flexible conduits and 90 degree condulets for further inapection by the industry experts. Mid-run flexible conduits or 90 degree condulets found were selected for confirmatory walkdown.
1.1.4 Selection criteria for walkdown for pullby Conduits containing 8 or more VI, V2, or V.) cables and V4 conduite containing 4 or more cables were examined.
These conduits are further reviewed by using the pull cards to determine the date of pull for each cable.
The conduits which contain cables pulled on different dates are selected.
Additionally, the conduits must be 50 feet in length or longer and contain 180* or more in bends, as determined from the preliminary walkdown.
These conduits are selected for confirmatory walkdown inspection.
1.2 Confirmatory walkdown methodoloav some Unit 3 activities have been completed. Where Unit 3 activities are specifically discussed, the planned approach for Unit 1 is the same.
The Unit 3 selected conduits were walked down for the following attributes in accordance with walkdown procedure DC-015.
The methodology is summarized below.
1.2.1 A free hand sketch of the conduit run was drawn during preliminary walkdowns to describe the bending directions, conduit size, condulet size, type, manufacturer and sites of pull boxes.
The sketch facilitated-the experts review.
1.2.2 The cable number, mark letter, manufacturer and jacket type were recorded. Outside diameters of cables were also measured and recorded during this walkdown.
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ENCLOSUllE I ADDITIONAL INFORMATION CONCERNING llFN UNITS 1 AND 3 CAllLE INSTALLATION ISSUES CORRECTIVE ACTION PLAN 1.2.3 After tbn confirmatory walkdowns are completed, the industry experts answer the following questions for the selected conduits.
(a)
Were any condulets or boxes physically installed such that they could D21 be used as pullpoints?
(b)
Was there any evidence of the use of cable pulling lubricant?
(open condulets and boxes and inspect for evidence of lubricants.)
(c)
Was conduit used for a dedicated run, i.e.,
no pullbys?
(d)
Was flexible conduit installed in mid-run of rigid conduit?
(e)
Do cables in conduit have different jacket materials?
If so, what are materials?
(f)
Is there evidence of damage to insulation or jacket as observed in condulets or junction boxes? If so, describe.
(g)
Does it appear that mechanical assistance was required for cable pulling due to conduit configuration and conduit fill?
If so, explain.
(h)
Does the estimated length between pullpoints exceed 100 feet?
(i)
Does estimated number of degree bende between pullpoints exceed 360'?
(j)
Is the conduit oriented in a horizontal or incline plane at the pull point such that pulling lubricant could not have been poured in to conduit?
(k)
Do cables in this conduit fall within jam ratio of 2.8 to 3.17 Complete this question it there are single conductor wires site #10 AWG or larger in a sinJ1e conduit.
(1)
Were any spare or abandoned cables observed in the conduit?
(m) was a pull rope or pull wire left in the conduit? If yes, describe the type of pull rope in the comments section.
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ENCLOSURE 1 ADDITIONAL INFORMATION CONCERNING BFN UNITS 1 AND 3 CABLE INSTALLATION ISSUES CORRECTIVE ACTION PLAN (n)
If the conduit or any portion of it is vertical, does its effective vertical drop exceed 25% of the allowable length in the Ceneral Construction Spccification G-38 for the applicable cable size?
If so, describe the cable condition at the top of the run (90 degree condulet, 90 degree field bend, horizontal or vertical cable tray, etc.).
)
Based on their findings, the confirmatory walkdown team reports their assessment of Units 1 and 3 installation practices, and concludes whether or not installation practices were similar to Unit 2.
2.0 Q1her Issues Walkdowns associated with resolution of the following issues involve a specific approach for each issue as discussed in TVA's May 10, 1991 letter.
A summary of TVA's approach to thens walkdowns is discussed below.
2.1 Bend radius Some Unit 3 activities have been completed.
Where Unit 3 activities are specifically discussed, the planned approach for Unit 1 is the same.
The selection criteria and walkdown methodology for Units 1 and 3 involve the same approach that was taken for Unit 2.
2.1.1 Selection criteria for walkdown DFN Unit 3 specific safety-related medium voltage (VS) power cables were walked down and evaluated against the criteria of 0-38.
2.1.2 Walkdown methodology The selected cables were walked down in accordance with Walkdown Procedure BC-004 to determine if the bend radius has been violated. The attributes walked down and recorded were cable ID, mark no., diameter and bend radius. An engineering analysis is performed using this information.
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ENCLOSUllE 1
\\
ADDITIONAL INFORMATION CONCERNING HFN UNITS 1 AND 3 CABLE INSTALLATION ISSUES CORRECTIVE ACTION l'LAN 1
2.2 Ygr11 cal suonorts The selection criteria and walkdown methodology for Units 1 and 3 involves the same approach as for Unit 2.
2.2.1 Selection criteria for walkdown 0-38 specifies vertical cable support criteria.
For Unit 3, the single-line drawings and physical layout drawings were used to prepare a list of the raceways / cables requiring walkdown inspection for vertical drops using the following criteria (a)
Safety-related vertical tray sectiors equal to or greater than 8'-6" require walkdown.
(b)
Safety related conduits with vertical lengths equal to or i
greater than 25% of the cable support spacing specified in 0-38 require walkdown.
(c)
Safety related medium voltage raceways / cables require walkdown.
2.2.2 Walkdown methodology Selected raceways and cables are walked down in accordance with walkdoen procedure DC-004.
Data la collected for each vertical drop to document the followings (a)
Conduit fittings or junction boxes at the top of the vertical drop, (b)
Cable jacket deformation and cable stress at conduit fittings, junction boxes or trays, (c)
Effactive vertical drop length, in accordance with G-38, (d)
Existing cable support, and (e)
Raceway layout.
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-,, - - - < - + - -. -, -., -
t ENCI,OSUl(E 1 ADDITIONAL INI:OltMATION CONCliitNING lil:N UNITS 1 AND 3 r
CA131.liINSTALLATION ISSUllS COltitliCTIVil ACTION PLAN 2.3 Missino conduit bushinas The selection criteria and walkdown methodology for Units 1 and 3 involve the sare approach that was taken for Unit 2.
l 2.3.1 Selection criteria for walkdown i
The missing conduit bushings program was a result of missing bushings that resulted in damage to type PN cables, conduit installations with missing bushings are located during the integrated walkdown of 10CFR$0.49 cables, within the harsh environments and to the first box into the mild environments.
The walkdown teams open and inspect junction, pull or conduit boxes containing these cables.
2.3.2 Walkdown methodology At the time of the 10CFh50.49 cable walkdown, enclosures that are opened are checked for missing bushings in accordance with walkdown procedure DC-004.
The cable ID and the location of the enclosure is recorded and the cables are checked for damage due to missing bushings.
2.4 pse of condulets ne null noints for larae 600 V cabing The selection criteria and walkdown methodology for Units 1 and 3 involve the same approach that was taken for Unit 2.
2.4.1 Selection criteria for walkdown BFH Unit 3 specific safety-related low voltage (V4) cables size 300 MCM and larger that are routed in conduit were walked down.
2.4.2 Walkdown methodology cables walked down for this issues are checked for damage and the findinge recorded. The condulet site, type, manufacturer and location were recorded, along with cable ID, mark number, conductor size, and number of conductors.
This is in accordance with walkdown procedure BC-004, i
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i ENCLOSURE 1 ADDf!!ONAL INFOllMATION CONCEltNING llFN UNITS 1 AND 3 CAllLE INSTALLATION ISSUES CORitECTIVE ACTION l'LAN t
2,6 CCR$ validation Unit 3 activities are discussed below.
The planned approach for Unit 1 is similar.
2.5.1 F. election criteria for walkdown Utilizing CCRS and data from the DFN Unit 3 10CFR$0 Appendix R, 10cFR$0.49 Environmental Qualification and Q-List programs, approximately 7,000 cables were selected to inake up a safety related population. The remaining population of approximately 18,000 cables are considered the non-safety population.
In accordance with engineering procedure 4.90-08, a random selector program was used to provide a sample of 58 safety and $8 non-safety cabico.
The following represents a breakdown of the sampled cables:
T SAI LTY kl1ATED CCR$ SAMPLE NON S AflTY CCRS S AMPLE VJLTAGE Ll' VEL NO. OF CAHLM APPROXIM AT E NO. VOLT AGE LEVEL NO, OF CAllLES APPAONIM ATE NO.
IN SAMPLE OF C AHLES IN IN $ AMPLE OF CAllLM IN TOTAL TOTAL POPULATION M)PULATP.,N VI i
130 V8 3
2300 V2 3
15 V2 13 3400 V3
$0 6(k 0 V3 37 10400 V4 3
700 V4 3
tyrK)
V5 1
50 V5 0
50 SYSTt M NO, NO. OF CABLES APPROXIM ATE NO.
SYSTDI NO.
NO. OF CABLES APPROXIM ATE NO.
(SEE NC/TE I)
IN SAMPLE OF CABLES IN
($EE NOTE 1)
IN $ AMPLE OF CABLi'S IN TOTAL.
TOTAL POPULATION POPULATION (KC i
400 (XU 2
1600 001 5
380 (01 2
500 002 1
3 002 3
1600 03 I
Ii$
003 2'
625 027 1
330 003 1
250 047 1
3 006 4
720 (54 4
380 024 2
J60
(*R I
100 027 3
360 069 2
90 035 i
~120 070 1
160 039 I
220 071 6
400 (40 1
60 073 2
410 043 1
215 074 4
960 047 2
640 076 1
200 056 1
140 1
7
_ _ _ _ _ _ - - - _ _.. _ _ - - - _. _ _ _ -_ _ _ _ _. _ _. ~ _ _ - _ _ _ _ _. _. __ _
ENCLOSUREI l
ADDITIONAL INFORMATION CONCERNING IlFN UNITS 1 AND 3 CAllLE INSTALLATION ISSUES CORRECTIVE ACTION PLAN
$ Al ETY RELAT ED CCR$ SAMPLE NON-SAFLTY CCR$ $ AMPLE SYSTEA1 NO.
No. OF CABLIS APPROXIM ATE NO.
$YSTLM NO.
NO. OF CABLES APPROXIM AT E No.
IN & AMPLE OF CADLES IN IN SAMPLE OF CAllLES IN TOTAL TOTAL loPULATION loPULATION 077 1
33 (63 1
40 078 1
53 064 2
480 Oll2 1
270 066 3
$75 OR$
4 Bio 068 1
670 (No 7
270
%9 633 244 1
173 074 1
360 254 1
10 082 2
70 237 8
260 083 4
1390 298 2
530 (N2 1
400 281 1
202 1
60 244 2
(70 23R 4
300 260 2
90 263 1
140 BUILDING NO. OF CAllLES
$[E NOTES 2 AND 3 DUILDING NO, OF CAisLES
$0E NOTES 2 ANf;3 IN 5 AMP 1 E IN SAMPLE Resetor illJg, 42 Reettor IllJg.
15 Conirul hay 24 Control llay 28 Drywcil 8
Drywe11 1
Turbine Bldg.
3 Turbine illJg.
2.3 Dieul Gen.111dg.
4 Diesel Gen. Bldg.
2 off Una Trestnwn 0
OIT. Gas Treatment 2
Itidg.
fildg.
Note 1:
System numbers correspond.to the following plant systems at BFN.
000 Spare Local Panels and Hiscellaneous 001 Main Steam System 002 Condensate and Demineralized Water System 003 Reactor Feedwater System 005 Extraction Steam System 006 lleater Drains and Vents System 023 Residual lleat Removal (RHR) Service Water System 024 Raw Cooling Water System 027 Condenser circulating Water System 035 Generator l{ydrogen System Co Storage, Fire Protection, and Purging System 039 y
040 Station Drainage Sytem 043 Sample and Water Quality System 047 Turbine Generator Electro-Hydraulic Control System f
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ENCLOSURE 1 ADDITIONAL INFORMATION CONCERNING BFN UNITS 1 AND 3 CABLE INSTALLATION ISSUES CORRECTIVE ACTION PLAN Note 1 (cont'd):
056 Temperature Monitoring System 063 Standby Liquid control System 064 Primary Containment Isolation System 066 off-Gas System 068 Reactor Water Recirculation System 069 Reactor Water cleanup System 070 Reactor Building Closed Cooling Water System 071 Reactor Core Isolation Cooling System 073 High-Pressure Coolant Injection System 074 RHR System 076 Containment Inerting System 077 Radwaste System 078 Fuel Pool Cooling and Demineralizing System 082 Standby Diesel Generator System 085 Control Rod Drive System 090 Radiation Honitoring System 092 Neutron Monitoring System 202 4 KV Unit Boards 244 Communication System 254 Diesel 125-Volt DC System 257 Reactor Protection System 258 Operation Recorder 260 Security Including Door Interlock and Alarm System 263 Condenser Tube Cleaning System 281 250-V Reactor Motor Operated Valve Boards Note 2:
No Index devoted to building identification exists for CCRS.
Note 3:
Cables located in two or more buildings are counted for each building.
2.5.2 Walkdown methodology Walkdown procedure BC-008 was developed to collect the attributos o' the cables by the walkdown team.
These attributes are to-from, size, route, mark number and cable ID for the safety and non-safety samples.
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ENCLOSURE 2
SUMMARY
OF COMMITMENT The results of the walkdowns will be discussed in a final report on the resolution of cable installation issues.
The report will be similar to the Cable Issues Walkdown and Sunguary Reports issued for BFN Unit 2 and transmitted to NRC by TVA letter dated June 19, 1989 and the Electrical cable Separations Report transmitted by letter dated January 6, 1989.
The Unit 3 report will be submitted prior to restart of Unit 3.
The Unit I report will be submitted prior to Unit I restart.