ML20217C472

Responds to NRC Re Violations Noted in Insp Repts 50-269/91-09,50-270/91-09 & 50-287/91-09.Corrective Actions: Inoperable Flow Transmitter Repaired & Crossover Flow Instrumentation on Two Units Checked

ML20217C472
Person / Time
Site:	Oconee
Issue date:	07/11/1991
From:	Tuckman M DUKE POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9107150332
Download: ML20217C472 (6)

Text

.;

. Il I f o c / u , , r, n . s ,

us 7,orn t , n. u.:, ,

, , l. . r n o m , i ,, -

. I'n 1; a la V - a t o, ~ <

( ') or **%{' *s  : } }J

• rh-lo s l%ij outit Powen July 11, 1991 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555 Subject Oconee Nuclear Station Docket Nos. 50-269, -270, -287 Inspection Report 50-269, -270, -287/91-09 Reply to Notice of Violation Gentlemen ,

By letter dated June 13, 1991, the NRC Jesued Inspection Report Nos. 50-269/91-09, 50-270/91-09 and 50-287/91-09 with a Notice of Violation. Pursuant to the provisions of 10 CFR 2.201, I am submitting a written response to the violation identified in the above Inspection Report.

I declare under penalty of perjury that the statements set forth herein are true and correct to the best of my knowledge.

Very truly yours,

k. h.

M. S. Tuckman, Vice President Nuclear Operations rnov710.lbj xc: S. D. Ebneter Regional Administrator, Region II L. A. Wiens, ONRR NRC Resident Inspector Oconee Nuclear Station i

9107150332 910711 PDR ADOCK 05000269

/ff

/ I I J Q PDR

{l

VIOLATION J t27 0 2 87 / 91- 09-01) , SEVERITY LEVEL _{1111 Technical Specification 3.3.1.c(1) requires valves llP-409 and

!!P-410 to be operable whenever reactor power is greater than 60 percent of f ull power. Technical Speci fication 3.3.1.c(2 ) requires that if the above valves are inoperable and are not restored to operable status within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, reactor power shall be reduced to below 60 percent of full power within an additional 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />.

Technical Specifications define operable as all essential instrumentation required in order to assure performance of the saftty functions being capable of performing its related support functions.

Contrary to the above, valves 311P-409 and 211P-410 were inoperable for greater than 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> as described below, and during numerous periods of reactor operations reactor power was not reduced below 60 percent of full power within an additional 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />s:

1. Valve 311P-409 was inoperable from May 1984 until March 1991, due to the fact that the liigh Pressure Injection crossover flow instrument to the "B" liigh Pressure Injection lloader was inoperable as a result of modifications to the flow instrumentation that resulted in the impulse lines being reversed.

2. Volvo 211P-410 was inoperable f rom initial installation in 1980 until March 1991 due to the fact that the :ligh Pressure Injection crossovor flow instrument to the "A" High Pressure Injection header was inoperable as a result of the orifice plate in the flow elemunt being installed in the reverso direction.

RESPONSE TO 311P-409 PROBLEM:

1. Reason for the violation:

Valve 311P-409 was considered to have been inoperable because indications would have shown no flow through 311P-409, potentially preventing safety functions from being adequately performed if this backup line had to be used.

The violation occurred due to insufficient post modification testing. In May 1984, a flow test was not specified to be performed as part of Nuclear Station Modification (NSM) ON-1782 Part u, which replaced the llPI crossover flow instrumentation and impulse lines.

~',' .

NRC Violation Rosponso P'ge Two In November 1988, Oconee's current Post Modification Testing program was implemented. The program requires testing to be performed that verifles proper installation / operation and verifies that the installed NSM performs as intended according to its desigli.

In March, 1991 it was discovered that the lupulse lines cad boon reversed during 1984. This discovery was the result of NSM ON-32589 being performed, which specified that as part of the post modification testing following the installation, flow would be established through.each crossover loop.

2. The corrective stops which have been taken and the results achieved:

The inoperable flow transmitter was repaired by reversing the  :

lines betwoon the manifold and the transmitter. ,

The transmitter was verified operable by the performance of a positive flow test.

The crossover flow instrumentation on the other two units was checked and the impulse lines were found to be tubed correctly, in addition, an evaluation was made concerning what other saf ety-significant instrumentation could be susceptible to

-this kind of-error. Because actual use of instrumentation immediately reveals- " rolled" tubing connectiona, safety-significant instrumentation which is not used during routino operation or testing was identified. The Standby Shutdown Facility-(SSF) Auxiliary Servict Water (ASW) flow instruments -

for the two steam generators en each unit woro identified as tha - only safety-significant _ instrume.itation which is not actually used during operation- or testing. All tubing connections on the SSF ASW flow instrumentation were physically verified on all three units. No tubing errors or other problems woro found.

3._ Corrective steps that will be taken to avoid further violations:

Unita 1 and 2 crossover flow instrumentation will be positive flow tested as_part of the Post-Modification Testing program Jn the next outage in which the instrumentation on these units will also be upgraded to Laprove accuracy. The current Post Maintenan00 end Modification Testing programs, as upgraded in 1988, require testing or other verifications which would identify this type of problem before returning equipment to serv 1Co.

t l:

NRC Violation Responso Pago Threo

4. Dato when full compitance wil] be achieved:

Full ,; mplianco has been achiaved through the actions listed in (1) and (2). As an additional verification, flow testing of the Unit 1 and 2 IIPI crossover instrumontation will bo performed as follows:

-Unit 1 crossover flow instrumentation will be tostod during the End of Cycle 13 Refuelirag Outage (scheduled to begin August 1, 1991) ,

l Unit 2 crossover flow institumentatioti will be tested during l the End of Cyclo 12 Refueling Outage (scheduled to begin January 2, 1992) e RESPONSE TO 211P-410: ,

i

1. Reason for the violation:

Valvo 211P-410 was consirfored to have boon inoperable because the indicated flow would have been loss than actual, so that runout protection for the High Pressure Injection pump might not have boon adequcto, if this backup lino had to be used.

The violation is the result of personnel error. In 1980, under. Nuclear Station Modification (NSM) ON-1080 Part A, the orifice plato was installed in the reverso direction. The procedure used for tho installation contained a sign-of f stop that stated, " Instal). orifico platos in proper direction of flow and in accorda"tco with MP/0/A/1800/3, Replacement of Caskets in Flanges". However, tho method for determining the

--proper direct 'on of flow was not included in the procedure.

The step was t.gned of f by the craf t supervisor. The step was followed by a Quality Control verification that the flango was installed correctly.

2. The corrective steps which have.been taken and the results achieved:

Design Engineering. performed an operability evaluation based L on calculation 05C-4323. This evaluation showed that by limiting indicated flow to 300 gpm all requirements would be mot even with tho flow orifice reversed.

l i

,. m*  ;

i NRC Violation Response Page Four The Emergency Operating Procedure was revised to limit the maximum indicated flow through the 'A' crossover loop to 300 gallons per minute. Operators wore given training on this change.

An identical oritice was fabricated and testod to obtain flow data in order to confirm the operability evaluation.

All other accesssible safety-signJficant flow orifices were inspecteo for. proper orientation. Three additional errors were discovered: Unit 1 'B' Reactor Building Spray (RBS) flow orifice, Unit 2 'B' RBS flow orifice, Unit 2 'B' Emergency Feedwater (EFW) flow orifice. The 1 'B' and 2 'B' RBS flow I orifices ware corrected. An operability evaluation was performed for the 2 'D' EFW flow orifice. It was found to be operable, as the of fect upon indicated flow would not be large enough to af fect the flow -instruments safoty functions. Three remaining safety-related orifices (for the SSF Reactor Coolant i flow on each unit)

Makeup (RCMU) located in the Reactor Building will be inspected during the next outage of suf ficient length. If an SSF RCMU flow orifice were reversed, it would not prevent the system from performing _its safety-function.

3. Corrective steps that will be taken to avoid further violations:

a. The reversed HPI flow ort.fice will be reinstalled in the correct position during the next outage - of sufficient duration.

b. The reversed EFW flow crifice will be reinstalled in the correct position during the f. ext outage of sufficient duration. In addition, the orifice will be inspected for degradation before reinstalling.

c. The three remaining safety-related flow orifices (one per unit) will be inspected to ensure correct installation.

d. Maintenance personnel having responsibility- for installation of orifices will be trained on the importance of proper incta11ation and given training concerning the installation of basic types of orifices i emphasizing the guidelines set forth in NRC Information l

Notice 90-65.

l

e. The Nuclear Station Modification Program will be revised to ensure that . procedures to install orifice plates include instructions that define the direction of flow within the piping.

~_ - _ . . - __ ._ _ _ . _ _ _ _ - . _ __ _ . . _ _ _ _ _ _ _ _ _ _ _ _ _ _

NRC Violation.Rosponso Page Fivo

4. Dato when full compliance will be ach.ioved

a. Thee Unit 2 llPI flow orifico will be reinstalled in the correct position before complot. ion of the End of Cyc)o 12 Itofueling Outage (scheduled to begin January 2, 1992).

b. The Unit 2 EFW flow orifice will be checked for degradation and reinstalled in the correct position bef oro completion of the End of Cyclo 12 Ref ueling Outago (scheduled to uogin January 2, 1992),

c. The S3F RCMU flow orificos (eno por bnit) will be inspected before completion of the next refueling outage Unit 1 EOC 13 Refueling Outage - scheduled to begin August. 1, 1991 Unit 2 EOC 12 Refueling Out. age - scheduled to begin January 2, 1992 Unit 3 EOC 13 Refueling Outage - scheduled to begin June 4, 1992

d. Maintenanco personnel responsiblo for orifico installation will be trained by December 31, 1991,

o. The NSM program will be revised by December 1, 1991 to provido ins t ruc t. ions concerning orifico plate installation and flow direction within the piping.

t

- _ . . _ _ _ _