ML20206P298

Forwards Responses to RAI Re GL 96-05, Periodic Verification of Design-Basis Capability of Safety-Related Movs, Cancelling 990402 Submittal

ML20206P298
Person / Time
Site:	Grand Gulf
Issue date:	05/13/1999
From:	Hughey W ENTERGY OPERATIONS, INC.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20206P301	List: ML20206P298 ML20206P362
References
GL-96-05, GL-96-5, GNRO-99-00042, GNRO-99-42, NUDOCS 9905180208
Download: ML20206P298 (8)

Text

e v .

Entsrgy rctions, inc.

O/ Port Gbson. MS 39150 W 601437-6470 W.K.Hughey Doector Nxtear Safety & Raplatory May 13,1999 {

l l

U.S. Nuclear Regulatory Commission Mail Station P1-37 Washington, D.C. 20555 Attention: Document Control Desk

Subject:

Grand Gulf Nuclear Station Unit 1 ,

Docket No. 50-416 I License No. NPF-29 Response to Generic Letter (GL) 96-05 Request for Additional Information j l

GNRO-99/00042 Gentlemen:

By letter dated February 1,1999 (GNRI-99/00002), the NRC requested additional information from Grand Gulf Nuclear Station (GGNS) regarding GL 96-05, " Periodic Verification of Design-Basis Capability of Safety-Related Motor-Operated Valves". This information was discussed during a conference call with the NRC on January 26,1999, and the responses were provided to you in a submittal dated April 2,1999 (GNRO-99/00030).

The April 2,1999 submittal has been cancelled and is superceded by this revised submittal.

In the first submittal, the information provided in Appendix B was marked as proprietary.

This information came from a report prepared under contract for Entergy Operations, Inc.

and became the property of Entergy with permission granted to use the material contained in the report. Therefore, the information in the submittal can be used in the response and, indeed, is not proprietary. This information has not been changed, but provided in a different format to remove any reference to proprietary information. ,

Please contact Ms. Rita Jackson at (601) 437-2149 if you have questions regarding this submittal. I f

Yours truly, Lk l

M

(

WKH/RRJ attachment: Response to NRC RAI for GL 96-05 cc: (See Next Page) 9905180208 990513 PDR ADOCK 05000416 P PDR L .. .

J

s GNRO-99/00042 Page 2 of 3 cc: Ms. J. L. Dixon-Herrity, GGNS Senior Resident (w/a)

Mr. L. J. Smith (Wise Carter) (w/a)

Mr. N. S. Reynolds (w/a)

Mr. H. L. Thomas (w/o)

Mr. E. W. Merschoff (w/a)

Regional Administrator U.S. Nuclear Regulatory Commission Region IV 611 Ryan Plaza Drive, Suite 400 Arlington,TX 76011 Mr. S. P. Sekerak, Project Manager (w/2)

Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 13D18 Rockville, MD 20852-2378

n

)

4 s l I

GNRO 99/00042 -

Page 3 of 3 bec: File (LCTS/RPTS)(w/a)

File (Hard Copy) (w/a)

File (Central)(w/a)( 22 )

ccmail: Mr. S. J. Bethay (w/a)

Mr. C. A. Bottemiller (w/a) j Mr. S. A. Burris (w/a)

Mr. R. W. Byrd (w/a)

Mr. L. F. Daughtery (w/a) i Mr. W. A. Eaton (w/a) l Mr. E. C. Ewing (w/a)

Mr. W. K. Hughey (w/a)

Mr. D. E. James (w/a)

Mr. R. J. King (w/a)

Mr. C. W. Lambert (w/a)

Mr.C. M. Renfroe (w/a)

Mr. J. C. Roberts (w/a)

Mr. J. J. Tumer (w/a)

Mr. J. D. Vandergrift (w/a)

Mr. J. E. Venable (w/a)

Mr. M. D. Withrow (w/a)

Mr. W. T. White (w/a)

s Attachment to GNRO 99/00042 Response to NRC Request for Additional Information Generic Letter 96-05

1. In NRC Inspection Report No. 50-416/96-03 (IR96-03) issued March 19,1996, the NRC staff closed its review of the motor-operated valve (MOV) program implemented at GGNS in response to GL 89-10. In the inspection report, the NRC staff discussed certain aspects of the licensee's MOV program to be addressed over the long term, with some of these aspects addressed in IR 96-20 dated January 8,1997. GGNS is requested to address the following:

A. The adequacy for blowdown of the thrust prediction model that remains open in IR 96-20 as IFl 50-416/96003-01.

Response: GGNS feels that this issue was adequately addressed in the letter written to Mr. Tom Scarbrough from Dr. Nabil Shauki on the subject of GGNS's GL 89-10 program. The letter discusses Siemen's grouping methodology and

' how it would identify major damage that would lead to unpredictable valve behavior. The unpredictability question also appears to have been addressed in the position paper from Wyle Labs addressing NRC concems regarding the GGNS grouping program. The position paper was issued February 22,1996 (Reference Number 45258R96), with NRC concern #3 being the question on valve damage. Appropriate portions of these referenced documents are attached as appendices.

B. The justification of the Powell gate valve factors remains open in IR 96-20 and also in IFl 50-416/96003-01. ]

1 Response: Additional dp testing per NRC request was conducted on 2 MOVs in Powell GA1600/900 pound class, as well as on 2 other MOVs in the Powell GA1150 pound class. Engineering Reports GGNS-98-0048 (600/900 GA1 class) and GGNS-99-0006 (150 GA1 class) document the test results. The results indicate that the valve factors of 0.5 (600/900 class) and .62 (150 class) supplied by Siemen for GGNS's grouping methodology are bounding.

Valve Class Calculated Valve Grouping Valve Factor Factor E12F027A 600 GA1 0.48 0.50 E12F042C 600 GA1 0.50* 0.50 P41F015A 150 GA1 0.49 0.62 P41F015B 150 GA1 0.46* 0.62 l

• Value is extrapolated i

. (

Attachment to GNRO 99/00042 C. The as-found testing for stem lubrication degradation that was not addressed in IR 96-20.

Response: The inspectors were looking for long term justification for not having a value dedicated to stem lube degradation. GGNS has been performing "as found" coefficient of friction (COF) testing on MOVs that have not been modified, have not been worked on, and those that have been previously VOTES tested. To date data is limited due to a large population of MOVs being previously MOVATS (displacement measuring device (DMT) and loadeell) tested. Many other MOVs have had actuator {,

modifications or valve modifications for margin improvements and were not "as found" I tested.

I The limited test data shows that the "as found" COF was less than the previous "as left" )

COF. This was seen in all tests except one. On this particular MOV, the "as found" COF increased by 8.9% over the previous "as left" COF It should be noted that this i MOV has always had a high COF and is at the maximum on its torque output.

Currently, the plan is to modify this MOV in RFO 10. Based on these results, GGNS still believes that 25% of packing load is sufficient to bound stem lube degradation.

l Collecting "as found' data for the effects for stem degradation is part of GGNS's trending program and will continue to be collected. The amount of"as found" COF data should increase since most of the previous MOVATS test with DMT/loadeell methodology have been replaced with VOTES test, and, most of the margin improvement modifications are complete. If the COF data starts to show that values are increasing, adjustments to the GGNS setup methodology procedures will be made.

D. The revision of open valve factor determinations to account for stem rejection forces that were not addressed in IR 96-20.

Response: The impact of adding stem ejection load to the measured open thrust used to calculate the open valve factors was assessed. It was concluded that overall this had a minimal impact on the calculated open valve factors. The open valve factors ,

calculated using the MS-49 data sheets were not used by Siemens when the group  !

valve factors were established.

E. The MOV trending program update that was not covered in IR 96-20.

Response: Per the request of the inspectors during the GGNS closeout audit, several trending parameters were added to the MOV trending program. Parameters that are trended and plotted per MOV trending procedure are as follows: Torque Switch Trip (TST) Thrust, TST Displacement, Unseat Thrust, Closed Running Thrust, COF, Seating Current, inrush Current, Running Current, Contractor Drop Out Time and Stroke time.

GGNS has purchased a VOTES Motor Power Monitor (MPM) unit and plans to start testing in 1999. MPM data will be added to the trend database in the future. 4

=

Attachment to GNRO 99/00042

2. Is the licensee applying the BWROG methodology for ranking MOVs based on thar safety significance as described in BWROG Topical Report NEDC-32264 and the NRC safety evaluation dated February 27,1996, for NEDC 322647 If not, the licensee should describe the methodology used for risk ranking MOVs at GGNS. ,

Response

GGNS used the November 1993 version of NEDC 32264 as the basis for the GGNS MOV safety significance ranking. This revision of the document is very similar to Revision 2. The primary difference is that Revision 2 includes discussion addressing such issues as: inter-system common cause and multi-component issues; scope of GL 89-10 versus the scope of PSA analysis; integration of probabilistic and deterministic methods of ranking MOVs; design basis capability and verification; testing intervals; changes in plant design or state of knowledge of valve categorization; and other considerations. It is our conclusion that none of this discussion would have resulted in changes to the basic risk significance ranking of MOVs for GGNS. The importance ranking and resultant categorization of valves was one of the factors utilized for establishing the frequency of periodic retesting.

3. The licensee is requested to describe the GGNS plan for ensuring adequate ac and de MOV motor actuator output capability, including consideration of recent guidance in Limitorque Technical update 98-01 and its Supplement 1. The licensee should address the setup of RCIC E51-F045 using 110% of de motor torque in its response.

Response: GGNS has the same setup criteria described in previously approved NRC inspections with respect to error calculations and setup methodology. All AC powered gate and globe MOVs in the Grand Gulf GL 89-10/96-05 programs were evaluated using Limitorque Technical Update 98-01 for guidance to determine potential operability and margin concerns. The evaluation was performed and addressed in Engineering

. Report GGNS-98-0038 and CR 1998-0819-00. As a result of the evaluations, GGNS implemented modifications in RFO9 and currently has plans for more modifications during RFO10 to increase MOV output capabilities to improve margin.

RCIC E51-F045 was identified in MNCR 95/0302 as exceeding MS-25 motor torque values. The condition was evaluated and showed that the motor was capable of delivering 110% of its rated torque. The NRC accepted this at the time. Their concern was how this valve would be effected by information expected to be issued by Limitorque regarding torque capabilities of DC motors.

Attachment to GNRO 99/00042 Limitorque, to date, has not issued a formal document on DC motors as they did on AC motors. GGNS is a member of the VTRG and is aware of the testing that has been performed to date and testing that will be performed in the future. DC motor torques are calculated at GGNS as allowed by Limitorque Technical Update 92-02. For all DC MOVs except 1E51F045, motor torque does not have to account for elevated ambient temperature effects because maximum expected temperatures under design basis conditions are less than Qualified Temperatures (i.e.,340* F) given in Table A-3 of Limitorque Technical Update 92-02.

1E51F045 had a motor gear changeout in RFO8 as a result of the available torque margin indicated in MNCR 95/0302. Close torque for 1E51F045 was increased by about 45%. Before gear change torque available was 861 ftlbs, and after the gear change it was 1254 ftlbs. As a result of the gear changeout, the torque is now set below the 100% rating of the DC motor torque.

I 4

i

. l s .

s i

Attachment to GNRO 99/00042 Appendix A Fax from Wyle Laboratories (Dr. Nabil Schauki) to Mr. Tom Scarbrough, NRC

Subject:

GL 89-10 Closure Meeting at GGNS and Inspection Report No. 50-415/96-03 This appendix is referred to in response to Question 1 of RAI I

I l

j