IR 05000259/1991014
| ML20138F841 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 04/22/1991 |
| From: | Merriweather N, Shymlock M NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| To: | |
| Shared Package | |
| ML20138F827 | List: |
| References | |
| 50-259-91-14, 50-260-91-14, 50-296-91-14, NUDOCS 9610180077 | |
| Download: ML20138F841 (10) | |
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e Mo UNITED STATES n
p oq'o NUCLEAR REGULATORY COMMisslON
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REGION 11
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101 MARIETTA STREET. N.W.
- ATLANTA, GEORGIA 30323
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Report Nos.:
50-259/91-14, 50-260/91-14, and 50-296/91-14 l
Licensee: Tennessee Valley Authority 6N 38A Lookout Place l
1101 Market Street l
Chattanooga, TN 37402-2801
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Docket Nos.:
50-259, 50-260 and 50-296 License Nos.: OPR-33, DPR-52, and DPR-68
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Facility Name: Browns Ferry 1, 2, and 3
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Inspection Conducted: March 25-29,1991
Inspector: gy
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N. Merriweather Date Signed i
Approved by: k
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n.,nymiock, Chief l
Plant Systems Section Date signed '
i Engineering Branch
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Division of Reactor Safety j
SUMMARY l
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Scope:
This special, announced followup inspection was conducted to assess Brans Ferry Nuclear (BFN) Plant's implementation of a program, pursuant to the requirements of 10 CFR 50.49, for establishing and maintaining the environmental qualification (EQ) of electrical equipment and to examine the corrective actions taken on NRC open items including a 10 CFR Part 21 Notification.
The categories of equipment examined included valve operators, level switches,
. temperature elements, junction boxes, MCOs, cables, and HVAC. level transmitters, flow switches, termina l
Results:
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The inspection confirmed that TVA has implemented an EQ Program at BFN which meets the requirements of 10 CFR 50.49.
The Program was.poroximately 90 percent complete with most of the remaining activities scheduled for completion
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after plant hydro testing.
The corrective actions on-NRC concerns discussed in
the June 1990 inspection report were complete for most of the items identified.
In those cases' for which corrective action was not complete, the licensee had initiated appropriate work requests to have the work performed.
During this
i 9610180077 910419 I
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DR ADOCK 0500
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I inspection, some minor concerns were identified in which the licensee propo acceptable resolutions.
A discussion of tnase concerns and the licensee's proposed resolutions are included in the report details in paragraph 2.
In the areas inspected, violations or deviations were not identified.
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i REPORT DETAILS
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1.
Persons Contacted Licensee Employees i
- J. Allen, Site Procedures Manager
- M. Batestani, Technical Support Manager
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- P. Carier, Manager, Site Licensing
- J. Delockery, Environmental Qualification Engineering Design Program Manager
- C. Hsieh, Compliance Engineer
- R. Martin, Senior Project Manager
- L. Myers, Plant Manager
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- E. Ridgell, Licensing Engineer
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- P. Salas, Compliance Licensing Manager
- J. Shaw, Engineering Support Supervisor
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- A. Sorrell, Maintenance Manager
- S. Smith, Unit Operations Manager
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Other licensee employees contacted during this inspection included craftsmen, technicians, and administrative personnel.
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NRC Resident Inspectors
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- K. Ivey, Resident Inspector
- G. Humphrey, Resident.'espector i
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- C. Patterson, Senior Resident Inspector
- Attended exit interview i
Acronyms and initialisms used throughout this report are listed in
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paragraph 5
Followup on Licensee's Implementation of the EQ Program (92701)
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a.
Background A previous NRC inspection conducted June 1993 concluded that TVA was implementing an EQ program that would bring BFN Unit 2 into compliance with the requirements of 10 CFR 50.49 prior to restart.
i However, full implementation of the EQ program required completion of certain activities, such as equipment replacement, modifications, engineering analysis, and documentation.
The June 1990 IR
(50-259.260.296/90-22l also identified several walkdown problems
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requiring NRC followup to verify appropriate corrective actica.
The licensee submitted a letter to NRC dated March 20, 1991 which provided a status on the major areas of work remaining to be performed prior to completion of the EQ Program.
The intent of this
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inspection was both to assess the adequacy of the EQ Program
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implementation and to examine the corrective action on the EQ
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walkdown problems discussed in IR 50-259,260,296/90-22.
Although,
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the program was still incomplete, over 90 percent of the EQ components had been qualified. Most of the outstanding work involved
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l the main steam system which was scheduled for completion after plant
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hydro testing.
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Inspections Details
Walkdown inspections were performed -on a sample of EQ components
located in the reactor building.
The sample included those i
components that were identified in the June 1990 IR as requiring
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- corrective action.
The components were physically exar.ined for
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as-built ins tallation characteristics such as mounting configuration,
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orientation, interfaces, nameplate data, moisture intrusion seals,
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weep holes, splices / terminations, internal wiring, and preservation j
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and protection.
The specific problems discussed in IR 50-259,260, 296/90-22 were re-examined to assess the adequacy of the licensee's
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corrective actions.
The inspector also examined the 50.49 list, EQ
binders, completed maintenance records and design d:cuments as needed
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to verify the qualified status of the EQ components examined.
l Interviews were also conducted with appropriate EQ staff to verify
program completion status as discussed in the licensee's letter to
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NRC dated March 20, 1991..
The observations made during the inspection and the conclusions reached are discussed in the following j
paragraphs for the specific components examined.
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(1) Flow Switch 2FS-074-050
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The previous inspection ' had observed that the panel box
.(No. 25-59) associated with this flow switch was very dirty with
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sufficient foreign material inside which could plug the weep i
hole.
The inspection had also noted that the flow switch had
been replaced due to rust problems.
The box was found clean with no foreign debris inside.
The terminal blocks associated
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with the flow switch terminations vere clean with no signs of
corrosion.
Terminal block No. TB A.A had signs of corrosion on s
terminal number three.
Discussions with the licensee confirmed that this was not an EQ circuit, however, the licensee indicated that appropriate corrective action would be taken.
(2) Level Transmitter 2LT-3-2088 The previous inspection noted that Conax Connector (2-CSC-003-2088) at JB-8116_was loose to hand pressure and JB-7720 was not sealed with RTV rubber.
The inspector noted that both junction boxes were gasketed, weep holes were in the bottom, and no foreign debris were in the boxes.
The conax real identified above was found tight at JB-8116.
No RTV seelant was found n
inside the boxes, however, the licensee indicated that these
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boxes were only required to be sealed externally around conduit
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fittings into the boxes.
The inspector had no further questions.
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(3) Level Transmitter 2LT-064-159A i
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conduit seal assembly was vertical and that the weep holes
drilled in the condulet would not permit water to drain out of j
the condulet.
This would allow water to stand on top of the
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seal for approximately 2-3 inches.
This problem was considered generic to several transmitter installations.
The licensee agreed to have all vertical conduit seals with condulets on the top filled with RTV rubber up to the first weep hole.
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subject transmitter had been reworked such that the conduit seal j
and condulet weep holes were now facing vertical down.
Thus,
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the above problem no longer existed.
However, several other Rosemount transmitter installations were observed to have vertical conduit seals with the condulet and weep holes on i
top.
All of these configurations were observed to have the I
condulets filled with RTV rubber up to the first weep hole.
(4) Temperature Element 2TE-064-1610 The previous inspection noted that the internal head potting compound did not completely cover the terminal olocks as required by the qualification test report and maintenance procedure.
The licensee repotted the above temperature element and inspected and reworked three others.
Subsequent to the June 1990 inspection, the licensee inspected and repaired the other j
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12 temperature elements in the system.
The inspector reviewed the completed work order records that documented the work and found them acceptable.
(6) Level Switch 2LS-073-056A/B The previous inspection noted that tne level switch housing was loose at the flange nut and the conax connection was loose at
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the condulet fitting.
The level switch housing on 2LS-073-056A
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was still loose at the flange nut, however, a work request had j
been documented to have the flange nut set screws replaced to a
different type.
The conax connections were all tight as I
verified by hand, however, the conduit for level switch 2-LS-73-056A was loose at junction box JB 8256.
The licensee was aware of this problem and had initiated a work request to have it tightened.
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(7)
Level Switch 2LS-085-045C/D j
j The previous inspection noted that the level switch housing on
2LS-085-045C was loose at the flange nut similar to i
2LS-073-056A/B above.
The connection was tightened by the licensee.
The inspector noted that the housing could be moved slightly by hand.
The licensee has initiated work requests to have the set screws replaced in conjunction with the other level switches.
(8) Radiation Monitors 2RE-90-272C and 273C
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Both the victoreen radiation monitors are required to have field cables that are completely enclosed within sealed conduits.
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previous -inspection noted that the Swagelock nuts and strain relief fittings on the sealed conduit installations were loose indicating the conduits were not completely sealed.
The licensee retightened the Swagelock nuts and strain relief fittings and committed to perform a system integrity check prior to restart.
The test has not been performed, however, the licensee has issued work requests to have the test performed.
j (9) Junction Box 2115 The junction box housed a GE Model CR 1518 terminal block.
The bottom and side entry conduits were sealed internally and externally with RTV sealant.
The box had weep holes and was observed to be clean and free of debris.
The terminal blocks were clean with no visible signs of corrosion.
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(10) Junction Box 2281
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The junction box housed two types of terminal blocks (GE Model CR 151B and EB-25A).
The box had weep holes with a metal divider.
On the right hand side of the box housekeeping was poor with loose cable tags, screws and debris observed, however, the terminal blocks were clean with no signs of corrosion.
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i left side of the box was clean with no signs of corrosion on the terminal blocks.
The licensee was aware of the f act that box
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JB 2281 needed cleaning and had issued Work Order No. 91-29117-00 to have the box cleaned.
(11) Junction Box 7404 The junction box housed GE Model EB-5 terminal blocks.
Housekeeping in the box was good with no signs of debris or foreign materials in the box.
The terminal blocks were clean with no visible signs of corrosion on the terminals.
The conduit entering the box was properly sealed with kaktight fittings. The bottcm entry conduits were sealed iraernally with
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.RTV and a weep hole was in the bottom of the box.
This installation was found to be acceptable.
(12)
J. unction Box 2706 This junction box housed EQ terminal blocks.
The conduits were sealed externally at the fitting and a weep hole was in the box.
Housekeeping in.the box was judged to be poor with loose screws, cable tags and tie wraps inside.
The terminal blocks were clean with no visible signs of corrosion or damage.
The licensee initiated a work request to have the box cleaned.
(13) Junction box 2130 l
This junction box housed GE Model CR 151B terminal blocks.
The top and bottom entry conduits were externally sealed at the
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The bottom entry conduits went. to hand switches i
HS-74-101B and HS-23-578 which were located dire-tly below
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junction box JB 2130.
The box had a weep hole in the bottom but the bottom entry conduits were not sealed internally with RTV.
The inspector discussed this configuration with the licensee and concluded that the box ~ was not properly sealed in accordance
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with design drawing DCA-H0397-007.
The bottom entry conduits were required to be sealed internally for this configuration above handswitches.
The licensee agreed and stated that other junctions boxes in a similar configuration above hand switches i
(approximately 40 to 50 boxes) would be inspected and properly sealed, if required.
The inspector considered this to be acceptable.
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(14) Motor Operated Valve FCV-23-57 This valve was qualified to prevent spurious operation during accident conditions.
The EQ binder was reviewed to determine the as-built configuration of the valve.
The walkdown i
inspection verified the critical as-built attributes such as T-drains, limit switch and torque switch materials, internal wiring, terminal blocks, splices, namepicte data, and mounting configuration.
The lubricants were confirmed by review of maintenance records to be the proper types for the main gear case and limit switch gear housing.
The local control station for this valve was included on the master list of EQ components (50.49 list).
Based on this review, the inspector concluded the
valve was fully qualified.
The local control station for this
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valve was associated with Junction Box JB 2130 above which did not have the conduits properly sealed internally.
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6 (15) Motor Operated Valves FCV-23-46, -74-67, -23-52,-74-25 and 74-74 The qualification binders for limitorque valve operators claimed qualifications for Raychem splices on braided motor leads with less than two inches of seal length.
The inspector reviewed the documentation being used by the licensee to support this position and found it to be inadequate.
The one test that was performed using Raychem on braided motor leads only states that a qualified Raychem splice kit was used.
The Raychem instruc-tion details require a minimum of two inches of seal length.
The licensee was not able to justify a splice with less than the manufacturer's required seal length.
To determine if any
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splices had been installed with less than two inches overlap i
the inspector selected these valves for examination.
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splices were found to be Raychem kits with adequate seal lengths.
The licensee informed the inspector that a total of 43 active valves (TVA EQ Category "a") have the braided insulation and could have splices less than the two inch seal length.
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Subsequent to the inspection, the records for the splices
installed in these valves were reviewed by the licensee to verify that the splices had a two inch minimum seal length.
Two valves were required to be inspected in the field to verify the
Raychem splices.
The results of this inspection revealed that the splices on valve 2-FCV-73-30 had a seal length less than the required two inch minimum.
The licensee has initiated Work
Request CO20921.to have the splices replaced. All other valves
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were determined to have qualified splices with two inches or greater seal length.
The licensee also stated during the inspection that they woul.d revise the EQ binders (MOV-001, -002,
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and -003) for limitorque' operators to specify a minimum of two inch seal length for Raychem splices on braided motor leads.
The inspector considered the above actions to be acceptable to resolve this concern.
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(16)
Reactor MOV Boards 2D/2E Compartment 2C The licensee has determined that the only harsh environment EQ t
function for 480V MOV boards 2D and 2E is to avoid spurious opening of two RHR LPCI Injection valves (2-FCV-74-53 and 2-FCV-74-67) during a reactor water clean-up line break outside primary containment.
For all other accidents the licensee had analyzed the boards as being in a essentially mild environment.
The licensee modified the boards under DCN W12327 by replacing control wire, terminal blocks, and hand switches with EQ qualified components and making'some changes in the control
circuitry for the open circuit seal-in relay contact and the thermal overload relay contacts.
The licensee determined that failure of these components in a harsh environment could cause
the valves to cycle open in a worst case scenario.
The d
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inspector examined Compartment 2C of Recctor M0V Board 20.
The inspector examined the interns 1 wiring and terminal blocks and verified that they had been replaced in accordance with DCN W12327. The inspector also reviewed the completed DCN and found it to be acceptable.
3.
10 CFR Part 21 Report (P2190-02) Ellis and Watts Air Conditioning Units (92701)
On September 20, 1989, TVA submitted a 10 CFR Part 21 Report regarding a significant safety defect in two Ellis and Watts Air Conditioning units installed at BFN Unit 2.
The defect involved the lack of environmental qualification for some of the electrical components and cabling supplied by the vendor.
The corrective acticn taken by the licensee involved a generic review of similar problems at other TVA Nuclear sites (i.e., CAQR l
BFP 890586); implementation of additional procurement controls and l
inspections for purchases from Ellis and Watts; and extensive rework and
l testing to upgrade the Ellis and Watts equipment at BFN to establish a oualified configuration.
During the June 1990 inspection NRC reviewed the
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EQ status of the parts and conducted walkdown inspections of the as-built configuration.
At the time of the June inspection, work was not complete on relocating and rewiring the electrical panels.
The inspector verified during this inspection that the DCN package (W10421A) that installed new cables and relocated the panels had been closed.
The panels were examined in the field and found to be energized.
The EQ qualification file (binder) has been updated to incorporate the as-built field verification data sheets and appropriate EQ test repor's.
The EQ maintenance has been performed and was baselined in the EQ da.a base (HEMS).
Based on the above, this item is considered closed.
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Exit Interview
The inspection scope and results were summarized on March 29, 1991, with those persons indicated in paragraph 1.
The inspector described the areas inspected and discussed in detail the inspection results as described in paragraphs 2 and 3 above. Proprietary information is not contained in this report. Dissenting comments were not received from the licensee.
5.
Acronyms and Initialisms l
BFN Browns Ferry Nuclear Plant-
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CAQR -
Condition Adverse to Quality Report r
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CFR Code of Federal Regulations
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DCN Design Change Notice
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EQ Environmental Qualification
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Harsh Equipment Maintenance System i
IR
Inspection Report
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Junctior, Box
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Level Transmitter
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Motor Control Center
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NRC
Nuclear Regulatory Comission
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Terminal Block
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TVA.-
Tennessee Valley Authority
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.HVAC -
Heating, Ventilation and Air Conditioning
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