IR 05000321/1988020

Insp Repts 50-321/88-20 & 50-366/88-20 on 880620-24.No Violations Noted.Major Areas Inspected:Environ Qualification of Electrical Equipment to Determine Adequacy of Licensee Corrective Actions on Previous Insp Findings

ML20153B819
Person / Time
Site:	Hatch
Issue date:	08/11/1988
From:	Conlon T, Casey Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
To:
Shared Package
ML20153B756	List: IR 05000321/1988020 ML20153B754
References
50-321-88-20, 50-366-88-20, NUDOCS 8808310106
Download: ML20153B819 (8)

Text

. .

'

-

'N*p "%,* AUS 1 A Iggg

'

- ** UNITED STATES g .; NUCLEAR REGULATORY COMMISSION o, f REGION li 101 MARIETTA ST., % ..,, g ATLANTA OEORGtA 30323 Report Nos.: 50-321/88-20 and 50-366/88-20 Licensee: Georgia Power Company P. O. Box 4545 Atlanta, GA 30302 Docket Nos.: 50-321 and 50-366 License Nos.: DPR-57 and NPF-5 Facility Name: Hatch 1 and 2 Inspection Conducted: June 20-24, 1988 Inspector: b M , k b 9 - Tgis-C. 3mMV Date 61gned Approved by /97t r7 7' / / -"68 T. Conlon, Chief Date Signed Plant System Section Engineering Branch Division of Reactor Safety SUMMARY Scope: This special, unannounced inspection was conducted in the areas of environmental qualification of electrical equipment to determine the adequacy of licensee's corrective actions on previous inspection finding Results: The inspection included an evaluation of the effectiveness of the corrective action program as it relates to (1) root cause analysis of identified deficiencies; (2) adequacy of developed corrective action plans; and (3) timeliness of implemented corrective action Strengths:

The corrective action program appeared to be effective in identifying ;

the root causes of deficiencies and developing corrective action j plans to specifically address these root causes. To better understand the issue concerning the effect of leakage current in instrument circuits, licensee management authorized the perfonnance of Wyle test ,

No. 4884 This test clearly demonstrated that non-conservative l leakage current errors of up to 1.25% of calibrated span, during a High Energy Line Break, was possible for a typical 4-20 MA transmitter / state terminal block circuit. Data obtained from this test ensured a technically sound approach for resolution of this l issue from a safety standpoint. Additional strengths were revealed )

by the timeliness of the implemented corrective actions, which were !

I

$$0* $858e 8s884!a PDC

'

- .

'

.

)

-

.

i

,

in accordance with licensee responses contained in their letter SL-430 s Weaknesses:

i Minor weaknesses were identified with the implemented corrective !

action for violation- (50-321/86-35-02; 50-366/86-35-03),

t Environmental Qualifications (EQ) Documentation for States Terminal Block Inadequate and (50-321/86-35-03; 50-366/86-35-04). EQ Documentation for Rosemount Transmitter accuracy during accident condition not complete. The Environmental Qualification Report Evaluation (EQRE) section of qualification file EQDP-4 was not revised -

-

to include'an engineering evaluation of Wyle test No. 48842, although the report and associated engineering correspondence were in the file.-

- Licensee management attributed this to an oversight. This deficiency j was corrected prior to the end of the inspection. Additionally, t licensee management will conduct a program review to ensure that the EQRE section of the qualification file is updated to include evaluations of all test report l

!

i I

J i

i i

i l

I

.

!

)

)

<

.

- -_ - . -

. .

..

,  ;

.

. i I

i

'

REPORT DETAILS

, Persons Contacted Licensee Employees .

• J. Bennett, Plant Training Superin'tendent  !

• J. Branum, Senior Nuclear Engineer  ;

E. Burkett, Project Engineering Supervisor i

• G. Creighton, Senior Regulatory Specialist t

• T. Elton, Plant Review Board Administrative Support Supervisor

• P. Fornell, Manager of Maintenance

• G. Goode, Superintendent General Engineering

• J. Lewis, Superintendent of Operations

• H. Nix, Plant Manager -

• T. Powers Engineering Manager

• D. Read, Plant Support Manager i S. Tipps, Manager Nuclear Safety and Compliance ,

>

Other Organizations ,

Southern Company Services

.

C. Pierce, Senior Engineer  !

J. Graham, Senior Engineer

'

?

NRC Resident Inspector

• R. Musser I

!

• Attended exit interview i Action on Previous Inspection Findings (92702) (0 pen) Severit Level IV Violation (50-321/86-35-02, )

50-366/86-35-03)y: EQ Documentation for States Co. Terminal Block <

Inadequate and (50-321/86-35-03; 50-366/86-35-04), EQ Documentation for Rosemount Transmitters accuracy during accident condition not compl et I The licensee response dated March 16, 1988, was considered acceptable by Region II. The inspector stewed Environmental Qualification Data Package (EDQP)-4 and verified that it had been updated to include Wyle test report number 48842. This test report,Section VI, describes the accident simulation test for the states teminal block /tramsitter, and states terminal block /RTD circuit Test acceptance criteria were also specified in this section of the repor The inspector reviewed the test data and interviewed licensee engineering consultants to verify the adequacy of the corrective actions take .

..

-

b

'

,

i

A review of Figure .VI-17. "States Terminal Block RTO Circuit and Reference RTD Temperatures" indicated that leakage ' current effects were insignificant and that the test acceptance criteria had been met for RTD circuits. Anomalies were identified, however, with the States '

,

terminal block / transmitter circuit. . An engineering evaluation was performed.on the test results by Southern Company Services (SCS) an ;

proposed corrective actions .were documented in letter LSH-NS-3937, i dated October 29, 198 This evaluation indicated a maximum, '

non-conservating error up to 1.25% of calibrated span was acceptable

'

for most Transmitter circuits. The inspector verified that instru- ,

mentation circuits that could have an error of 1.25% of calibrated span were identified and Justification of Continued Operation (JCO)

were prepared for both units.

'

SCS letter LSH-NS-3937 recommended that instrument circuits with a ,

potential leakage error of up to 1.25% of calibrated span be modified by replacing the terminal blocks with qualified Raychem Heat shrink

- kits. Similar recomendations were provided in SCS letter HTX 60-97, dated January 15, 1988. This letter further provides four groupings ,

of instruments, i.e., groups A, B, C. (Rosemount Transmitters), and D (Barton transmitters), for which the following actions were to be taken: group A - requires modification, group B - no modification ;

required, group C - revise set point calculation, and group D - !

revise set point calculations / leave as Barton transmitter The !

inspector determined that selected instrument circuits for Unit 2 had i

) been modified by design chan The inspector further reviewed l design change package (DCP) ges.87-194-0-1, revision 0, prepared for i implementation on Unit 1 to correct instrument circuits potential

'

l leakage current errors. Physical changes to be made involve

replacing existing terminal block connections with an inline bolted

splice connection using a either Raychem Nuclear grade heat shrink j i tubing or qualified Okonite T95 and No. 35 tape. In calculation 1

number H-87-30 the licensee, using insulation resistance values from !

] the vendor's test report, No. NQRN-3, demonstrated that the potential

-

leakage current errors contributed by taped splices are negligibl Additionally, environmental qualification of taped splice configura-tions was addressed on Attachment A to EQRE-1 Licensee had also i established environmental qualification by similarity based on Wyle j test report numbers NEQ 17947-01, NEQ 17850-02 performed for Alabama Power Compan !

1 The narrative design summary of DCP 87-194-01 listed instrument circuits from both groups A and D as requiring modification. This listing is different from that delineated in SCS letter LSH-NS-3937,

and HTX 60-97. Additional evaluations by the licensee hat' revealed l

. that adequate margin to include leakage current effects was available i

) in some instrumentation circuit set point values; or errors aused by l l the leakage currents would not mislead the operatur. Praposed j changeout of some Barton transmitters had also resu' % changes to

!

i i

1 I

!

I

l

!

l

>

.

l

.

the scope of the instrumentation circuits listed in the above letter Review of EQDP-4 did not show inclusion of the engineering evaluation for leakage currents. The anomalies identified in Wyle test report 48842-1 were also not documented in EQDP-4 as having been addresse Pursuant to the corrective actions taken by the licensee which are described above, and discussions with licensee consultants, the inspector determined that an assessment of the test results supported by calculations was indeed performed. Omission of this infomation, which would be included in section II of the EQDP, "Environmental Qualification Report Evaluation (EQRE)," was attributed to an oversight by licensee managemen Prior to completion of the inspection licensee management revised section II of EQDP-4 to incorporate the engineering evaluation into the environmental qualification file. A calculation was also perfonned which verified the leakage current error potential documented in Southern Company Services letter LSH-NS-3937. A program review to ensure that the EQRE is updated to include evaluation of all test reports, and a formal documentation of the above calculation will be performed by the licensee in response to these weaknesses in the corrective action progra DCPs87-195 implemented for Unit 2 and 87-194 prepared for Unit 1, permitted the use of taped splices in instrumentation circuit Licensee's decision to use taped splices in instrument circuits in lieu of the recommended Raychem Heat Shrink Kits was discussed with licensee's representatives over the telephone on several occasion The inspector also requested additional environmental qualification documentation used by the licensee to establish EQ qualification of the taped splices. These documents will be reviewed by the NRC to determine the technical adequacy of the methodology used. Pending completion of this review by the NRC, this issue is identified as Unresolved item 50-321/88-20-01, 50-366/88-20-01, Use of Taped Splices in Instrument Circuits, b. (Closed) Severity Level IV violation (50-321/86-3501, 50-366/86-35-02), EQ Documentation for Okonite Cable and Splices Inadequate and (50-321/86-04; 50-366/86-35-05), EQ Documentation for Target Rock Solenoid Valve Incomplet The licensee response dated March 16, 1988, was considered acceptable by Region I The inspector reviewed EQDP-29 "Okonite T-95 Insulating Tape and No. 35 Jacketing Tape," Revision 3, to verify the adequacy and effectiveness of the implemented corrective action Section 1.0 of the EQDP states that the tapes are qualified to 10 CFR 50.49 by type testing supplemented by Arrhenius Analysis. The EQRE had also been revised to show that the test results and analysis demonst ated that Okonite T-95 and No. 35 splicing are qualified to the spuified requirements. A caution note was also included to

___ _ J

l

. j

ensure that the shelf life of the tapes is not exceeded prior to installatio Section III of EQDP-29 contains EQ Report No. S43304-B, "LOCA Qualification Report for Okoguard Insulated Cables and T-95 and N splicing tape." The inspector determined that an addendum to the report has been added to this section of the EQDP. The addendum list insulation resistance (IR) values in meg-ohms per 1000 feet for Okoguard cable with T-95 and No. 35 taped splices. The IR values were measured at various time and temperature during the accident simulation test. Calculation number H-87-30, "Cable Splicing Tape Insulation Resistance," had also been performed to assess the potential impact on instrument loop accuracy because of leakage current contribution from cable splice This quantitative assessment of the potential loop accuracy error uses IR values delineated in the addendum. The results of the calculation show that typical instrurentation errors due to cable splice IR for Units 1 and 2 worst case condition (i.e. , T=330*F) is 0.004"F for RTD circuits and 0.0044% loop accuracy error for a typical 4-20 MA transmitter circui Review of EQDP-14 "0konite Power and Control Cables," verified that corrective actions similar to that implemented for EQDP-29 had been completed. The EQRE had been revised to state that the test results and analysis have demonstrated that the cable is environmentally qualified. Performance data had also been included as an addendum to Section III of the EQD A quantitative assessment of the per-formance data had been performed for Okonite instrumeatation cable only (Okonite Report NQRN-4). The result documented in calculation number H-87-29 showed that leakage current contribution from this type of cable is negligibl The inspector reviewed EQDP-10. "Target Rock Solenoid Valves, Models 73K and 75F," and verified that the environmental qualification file had been revised in accordance with licensee stated corrective actions. The EQRE had been expanded to fully establish similarity between model 73K 002, 003, 004, and 75F-008 and the tested valve, model 76HH-00 Basic design and construction of the valves were compared, including material differences for non-metallic component Calculation number 109, "10 CFR 50.49 Thermally Qualified Life of Non-metallics in Target Rock Solenoid Valves-model 73K-003," was performed to determine the thermal qualified life for replacement components in normally energized valves. The valves in question are model 73K-003, tag numbers D11-F050, F051, F052, and F053. The results of the calculation showed that the most susceptible non-metcilic component are thermally qualified for five years when the coil is normally energized. Additionally, the inspector verified that existing maintenance requiremer.ts documented in section VI of the EQDP ensures replacement of these parts every five year _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

. l

'

.

,

.

,

The inspector concluded that the licensee had determined the full l extent of the violation, taken action to correct current condition and developed corrective actions needed to preclude recurrence of ,

'

similar problems. Corrective actions stated in the licensee response have been implemente . Action on' Previous Inspection Findings (92701) (Closed) Unresolved Item (50-366/86-35-01), Limitorque Operators

,

Corrective actions taken by the licensee ir, regard to the environmen -

tal quelification of Limitorque valve motor operators and the !

preparation of JCOs are described in Georgia Power Company's letters SL1145, dated August 22, 1986, and SL 2107-01510, dated March 16, 198 !

Concerns regarding the preparation of plant specific JCOs for motor operated valves unqualified internal wiring were addressed in the above letter The inspector reviewed licensee corrective action tracking form prepared for disposition of motor operated valves EQ deficiencies and verified the followin All limitorque valve motor internal wiring inspections were completed for Unit 2 on November 14, 1986. A total of 169 maintenance work orders were prepared and completed for Unit 2 to resolve concerns addressed in IEN 86-03. Similar deficiencies-identified on Unit I were corrected by implementation of 129 maintenance work orders. The unresolved item is considered closed, (Closed) Inspector Followup Item (50-321/86-35-06; 50-366/86-35-07),

Walkdown Deficiencies The inspector reviewed the corrective action tracking form and response summary prepared for disposition of the identified deficiencies. The licensee had prepared the following maintenance work orders to correct the hardware deficiencies identified in the fiel MWO Number Item 2-86-6674 Loose actuator arm on NAMCO Limit Switch 2E41-F029 2-86-6577 Repair flex conduit on 2821-N301G 2-86-6580 Loose flex on 2T47-N00!M 2-86-7020 Replace flex on 2DII-N003B 2-86-9400 Replace missing screw in junction box teminal block for IT48-N210

_

. .

..

-

,

The root cause, as determined by the 1 . ansee, for the above deficiencies, was attributed to personnel errors with poor housekeeping also identified for the last ite The inspector reviewed ccpies of the above maintenance work orders and verified that the maintenance activities had been completed. This item is close (Closed) Inspector Followup Item (50-321/86-35-05, 50-366/86-35-06) ..

HighPressureCoolantInjection(HPCI)TurbineController In response to the maintenance deficiency identified by the NRC, licensee management conducted an investigation to determine the EQ maintenance requirements for the 'DC auxiliary lube oil pump motors (1E41-C002-3, 2E41-C002-3). Reviews were performed of EQDP-51 and 56. HPCI Instruction Manuals, Hatch procedures (52PM-E41-003-IS, and 52PM-E-41-003-2S), and vendor documents from General Electrical for direct current motor type CD frame 180-680 (S-27441), and type 180-680 (S-19823). It was determined that EQ maintenance requirements were not specifically addressed by either of these document The only vendor recommended periodic maintenance identified was a lubrication frequency of seven years. Plant Hatch procedure requires inspection of the motors, and lubrication of the bearings, if required, every six months. Final corrective action was completed in June 1987 when E0QP 51 and EQDP 56 were revised to incorporate the above maintenance requirement The inspector reviewed copies for the HPCI System Preventive Maintenance monthly procedure data package and verified that required maintenance was performed af ter June 198 Additionally, the semi-annual maintenance activities were verified as having been completed by review of signed off procedure data package This item is considered close . Exit Interview The inspection scope and results were summarized on June 24, 1988, with those persons indicated in paragraph 1. The inspector described the areas inspected and discussed in detail the inspection results. Dissenting comments were not received from the license Licensee's decision to use taped splices in instrumentation circuits in lieu of qualified Raychem Heat Shrink Kits was discussed with licensee's representatives over the telephone on several occasions. Additionally,EQ documentation required for review by NRC to resolve this issue was requested by the inspector. Licensee management was informed ti.at the use of taped splices in instrumentation circuits is identified as an Unresolved item, and violation (50-321/86-35-02; 50-366/86-35-03), EQ Documentation for States Co. Terminal Block Inadequate, and (50-321/86-35-03; 50-E0/06-35-04), EQ Documentation for Rosemount Transmitters accuracy during accident condition not complete, previously identified as closed at the exit has now been reopened.