NG-99-1358, Forwards DAEC plant-specific Response to 990927 RAI Re TS Change Request on Excess Flow Check Valve Surveillance requirements.TSTF-334,included

Forwards DAEC plant-specific Response to 990927 RAI Re TS Change Request on Excess Flow Check Valve Surveillance requirements.TSTF-334,included

ML20217D216
Person / Time
Site:	Duane Arnold
Issue date:	10/05/1999
From:	Peveler K IES UTILITIES INC., (FORMERLY IOWA ELECTRIC LIGHT
To:	NRC (Affiliation Not Assigned), NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
RTR-NUREG-1433 NG-99-1358, NUDOCS 9910150064
Download: ML20217D216 (9)

Text

.

j; ,

4 ,

' ALLiANT ENERGY.. iEs utiiities inc.

Duane Arnold Energy Center 3277 DAEC Road

. .. . Palo. lA 52324 9785 j

. October 5,1999.

Dmms45um

. NG-99-1358 : ret 31s asuses www.elliant-energy.com

/ Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Attni Document Control Desk -

. Mail Station 0-PI-17 j' Washington, DC 20555-0001

Subject:

Duane Arnold Energy Center (DAEC)

' Docket No: 50-331 Op. License No: DPR-49 DAEC Response to Request For Additional Information on Technical Specification Change Request (TSCR) -

Regarding Excess Flow Check Valve Surveillance Requirements

References:

(1) NG-99-0308, Letter from J. Franz (IES Utilities) to NRC, dated April 12,1999," Technical Specification Change Request (TSCR-010): Relaxation of Excess Flow Check Valve Surveillance Testing."

s

- (2) Letter from B. Mozafari (NRC) to E. Protsch (lES Utilities), dated September 27,1999, " Request For Additional Information on Technical Specification Change Request Regarding Excess Flow Check Valve Surveillance .

Requirements at Duane Arnold Energy Center,(TAC No.

MA05421)."

File: A-107a, A-117

- By reference (2), the NRC requested additional information regarding the Technical Sps.i.hation Change Request (TSCR-010)'we submitted to you in reference (1).

Enciced P the DAEC plant-specific response to your requested information. This

response is not intended to modify the Boiling Water Reactor Owners' Group report,

- B21-00658-01, which was submnted to you in reference (1).

There are no new commitments made in this letter,

• ^~

y 9910150064'991005

'! PDR ADOCK 05000331T

-P PDR ,  ;

I

October 5,1999 NG-99-1358 Page 2 If you should have any further questions in this matter, please contact Ken Putnam at 319-851-7238. i Sincerely, .

Kenneth E. Peveler Manager, Regulatory Performance

. Attachments:

(1) DAEC Response to R.equest for Additional Information on Technical Specification Change Request Regarding Excess Flow Check Valve Surveillance Requirements.

. (2) Industry /TSTF Standard Technical Specification Change Traveler, TSTF-334.

cc: J. Karrick E. Protsch (w/o)

D. Wilson (w/o)

B. Mozafari (NRC-NRR)

J. Dyer (Region III)

NRC Resident Office Docu 1

1 l

1 4

l

]

m Attachment I to NG-99-1358 Page 1 of 5 i t

DAEC Response to Request for AdditionalInformation on i Technical Specification Change Request Regarding Excess Flow Check Valve Surveillance Requirements

- NRC Question 1:

You have proposed a 10-year test interval for Excess Flow Check Valves (EFCVs), and have primarily referred to Option B of Appendix J to 10 CFR Part 50, as the model for doing this. However, you have neglected to address the fact that the NRC staff, through Regulatory Guide (RG) 1.163, limits containment isolation valve testing intervals to a maximum of 5 years. By licensees' requests, the RG has been incorporated by reference

{

into the Technical Specifications (TS) of every plant that is using Option B of Appendix (

J. Thus, the 5-year interval is a requirement for every plant using Option B.

Insofar as yourjustification for a 10-year interval is, for the most part, that it is like Option B of Appendix J, provide additionaljustification for your proposed interval that is longer than the 5-year interval used for Option B of Appendix J.

DAEC Response to Question 1:

A 10-year test interval is not proposed in this amendment request. Rather, a 24-month nominal interval, testing a representative sample is proposed. The valves in question are of similar design, similar application, and similar service environment. Performance of the representative sample provides a strong indicator of the performance of the total 1 population. The 10-year nominal interval solely limits the time between tests for any f specific valve and provides additional assurance that all valves remain capable of performing their intended function.

l l

It was not intended that the similarity to performance-based testing programs, such as )

Option B of Appendix J, form the primary basis of the change request. Rather, as stated in Reference (1), the basis for the amendment request is consistent with that described in a Boiling Water Reactor Owners' Group (BWROG) report, B21-00658-01. The failure rate data listed in Table 4-1 of that report, which includes zero failures in 25 years of operations at DAEC, is considered the primary basis for the performance-based interval.

In addition, the consequences of a failure to isolate have been evaluated and found to be acceptable with respect to off-site doses.

RG 1.163 is essentially an NRC staff endorsement, with exceptions, of a Nuclear Energy Institute (NEI) document,94-01, concerning the performance-based option of 10 CFR Part 50, Appendix J. Per RG 1.163,"Because of uncertainties (particularly unquantified leakage rates for test failures, repetitive / common mode failures, and aging effects) in historical Type C component performance data, and because of the indeterminate time

E N .

l Attachment I to NG-99-1358  ;

Page 2 of 5 period of three refueling cycles and insufficient precision of programmatic controls described in Section 11.3.2 [of NEl 94-01] to address these uncertainties, the guidance provided in section 11.3.2 for selecting extended test intervals greater than 60 months for

. Type C tested components is not presently endorsed by the NRC staff."

a

' We believe the data provided in the BWROG report shows that bases for limiting {

intervals to 60 months, as stated in RG 1.163, are not applicable to EFCVs. - Specifically:

e' Unquantified leakage rates for test failures are not applicable because the maximum

'~

> leakage through an unisolated instrument line is quantified as discussed in UFSAR :  :

1.8.11. The dose consequences of the failure to isolate, ac discussed in UFSAR

• 1.8.11, are acceptable.

I I

• . Repetitive /comm'on-mode failures are not applicable as evidenced by the low industry

. failure rate and more specifically by the BWROG report, Table 4-2, "EFCV Failure Rates by Manufacturer."~

• Aging effects are not a concern. The industry data already provided does not indicate

. any increase in failure rate with time in service.

. : Historical performance data associated with EFCVs has been provided and is

. considered adequate tojustify the proposed interval.

e' There is no indeterminate time period involved with this proposed change. Every 24 l

- months, approximrtely 20% of the total population (e.g. about 19 valves at DAEC) will be tested.

Therefore, we believe RG 1.163 and the 60-month limit for test intervals are not

- applicable to EFCV test intervals.' The reference to Option B of Appendix J in the amendment was a general reference to performance-based testing. EFCVs are not subject to Type C leak rate testing at DAEC. It was not intended to adopt or imply adherence to the details of the Option B program. Rather, the reference to Option B was made from a I conceptual viewpoint.

NRC Question 2:

Under the Appendix J, Option B, program, if a component on an extended test interval fails a test, it must be returned to the nominal test interval until subsequent testing re- i establishes its reliable performance. In other words.'ifit doesn't continue to perform well, it gets tested more often.~ Your proposal has no similar well-defined feedback mechanism for EFCVs. There is only the following:

EFCV test failures will be evaluated to determire if additional testing in that test interval is~ warranted to ensure overall reliability is maintained. (From the proposed DAEC Bases) i

r Y<

. Attachment I to NG-99-1358 Page 3 of 5 -

The risk-informed IST Regulatory Guide, RG 1.175, also specifies the need for a feedback mechanism.

1 Justify the absence from your proposal of an explicit, well-dermed performance feedback mechanism that requires increased testing when valves fail their tests, or add such a Lmechanism to your proposat DAEC Response to Question 2:

L Any EFCV failure would be documented in the DAEC Corrective Action Program as a

,1 Surveillance Test failure. The failure would be evaluated and corrected. The Corrective Action Program is capable of trending EFCV test failures and determining whether additional testing is warranted.'

Additionally, we have revised our 10 CFR 50.65 Maintenance Rule Performance Criteria to ensure EFCV performance remains consistent with the extended test interval.- The new

~

performance criterion is less than or equal to 1 failure per year on a 3 year rolling average.

When Performance Criteria are exceeded, the structures, systems or components (SSCs) in question are placed in Maintenance _ Rule 50.65(a)(1) status pending a problem review and the completion of correction actions. The problem review is undertaken via a root cause analysis performed in'accordance with the plant's Corrective Action Program. Per the DAEC Maintenance Rule Program, this 50.65(a)(1) re' view must encompass the past three years of the SSC's performance history (at a minimum) and include discussion of other applicable problem history. Industry Operating Experience (OE) mest also be considered. The 50.65(a)(1) review must also include a discussion of the cumulative and 1 instantaneous effects upon plant safety of the problem (s) as determined using the Plant Safety Analysis, and an examination of current SSC monitoring, trending, preventive and predictive maintenance activities. Corrective actions are then established and Goals are set and monitored in accordance with the NEI guidance for implementation of the Maintenance Rule. The Performance Criteria Basis document containing the criteria for EFCVs also specifically notes that_ significant failures of equipment monitored by the document will be evaluated under the OE Program for dissemination to the industry.

I NRC Question 3:

- The proposed Duane Arnold TS says "a representative sample of EFCVs will be tested every 2 years. The " representative sample" is not defined. Your proposed Bases, which, you are careful to point out, are not part of your proposed license amendment and are included for information only, say you will test 20% of the valves each refueling outage 3

rp?

! i,;

Attachtnent I to l

. NG-99-1358 )

Page 4 of 5 and thus test all of them in a 10-year period. In fact, the proposed TS would allow you to test less than 20% each time, and the concept of" representative" could change with time to exclude certain valves that were problems (e.g. repeat leakers, hard to access). The

. point is not that these things will actually happen, but that that proposed TS contain virtually no actual requirements.

Justify the absence of more specific requirements in the proposed TS, or add specific requirements to the proposed TS.

DAEC Response to Question 3:

The term t' representative sample," with an accompanying explanation in the TS BASES, is identical to current usage in the Standard TS (STS), NUREG-1433, Revis in 1.

Specifically, NUREG 1433 uses the term " representative"in TS Surveillance

Requirement (SR) 3.8.6.3, in reference to battery cell testing and " representative sample" in SR 3.1.4.2 for verification of control rod scram times. Therefore, the application of a

" representative sample" for the EFCV testing SR, with its accompanying definition in the BASES is consistent with the STS usage.

In addition, as required by the Technical Specification Task Force (TSTF) process for changing the STS, a generic traveler (TSTF-334), with similar SR wording as that y submitted in the DAEC plant specific submittal, has been submitted to the NRC for j

review (Attachment 2). One'of the primary reviews conducted by the TSTF committee is -

conformance to the Writer's Guide for TS, There were no concerns raised over the content, format or proposed use of the BASES. This traveler was approved by the TSTF on May 6,1999 and forwarded to the NRC for review on June 23,1999. The only

]

l_ difference between the DAEC wording and that in the TSTF is our deletion of the )

l_ clarifying details that the " representative sample" should be composed of various _ l configurations, model types, sizes and operating environments. At the DAEC, EFCVs are all similar models, with similar configurations and operating environments. i Therefore, the clarification in the generic traveler is not necessary to ensure that an I appropriate " representative sample" is chosen at each SR interval.

The proposed TS BASES change was provided "for information only" so that it would s not otherwise imply Staff approval of the BASES change upon issuance of the approved L / amendment. This is in conformance with 10 CFR 50.36 and Staff Policy. As stated in L - reference (1), the TS BASES are subject to the requirements of the Bases Control l Program of TS 5.5.10. Therefore, the requirements of 10 CFR 50.59 apply to changes to the content of the subject TS Bases section and NRC approval would be required if such a change resulted in an Unreviewed Safety Question or required a TS change, i

m Attachment 1 to NG-99-1358 Page 5 of 5  !

The BASES are routinely used to capture commitments imposed by the Staff as terms or

'~

conditions for approval of specific TS changes in their Safety Evaluation Reports (SERs). l

~ As noted in the generic traveler, the BASES change to evaluate any failures for possible l

expansion of the tested population is specifically characterized as a " commitment." We, therefore, do not agree that there are "no actual requirements" in the proposed -

amendment. As written, the proposed change is consistent with how other, similar testing programs that utilize a sampling approach are constructed in the STS. Thus, additional requirements within the TS proper are not needed.

i l

! I l-l 4

1 l

l I

j

Attachment 2 to NG-99-1358 1

1 I

I i

1 l

\

\

l I

I i,

I l

l l

i l

l l

l l

1 l

l l

l i

I l

i L_

1 i

• 5 (BWROG-63, Rev. 0) TSTF-334 IndustryffSTF Standard Technical Specification Change Traveler Relaxed Surveillance Frequency for Escess Flow Check Valve Testing Classification: 3) Improve Specifications i NUREGs Affected: u 1430 1431 _

,, 1432 g 1433 u 1434

Description:

Surveillance Requirement 3.6.1.3.10 (NUREG-1433) requires verification of the actuation capability of each reactor instrumentation line Excess Flow Check Valve (EFCV) every [18] months. This proposed change is to relax the i requirement to test every EFCV, by allowing a representative sample of EFCVs to be tested every [18] months, such that f all EFCVs will be tested at least once every 10 years (nominal). The proposed change is similar to existing performance-based testing programs, such as Inservice Testing (snubbers) and Option B to 10 CFR 50 Appendix J. As added assurance of detecting any potential common failure modes, the representative sample will be comprised of the various configurations, model types, sizes and operating environments of EFCVs in the plant.

Justification:

A review ofindustry operating experience demonstrates that EFCVs are highly reliable and that the incidence of test l failures is extremely low. Given the large number of EFCVs that are currently required to be tested each Refuel Outage

]

(typically 100), a significant cost and dose savings can be achieved by the proposed relaxation of the testing frequency l

without any reduction in overall safety or reliability. The Bases change includes a commitment to evaluate any failure to i isolate for the need to expand the tested population in that test interval. j i

(Note: Some plants may require an Inservice Testing Program Relief Request pursuant to 10 CFR 50.55a in order to l implement this proposed change.)

Industry

Contact:

Ford, Bryan (601)437-6559 bford@entergy.com NRC

Contact:

Giardina, Bob 301-314 3152 lbbl@nrc. gov Revision History l l

! OG Revision 0 Revision Status: Active Next Action:

l .- _. ___ _ _ _ _ _

Revision Proposed by: Duane Arnold Revision

Description:

Original Issue Owners Group Review Information Date Originated by OG: 09-Feb-99 Owners Group Comments (No Comments)

Owners Group Resolution: Approved Date: 09-Feb-99 TSTF Review Information TSTF Received Date. 16-Mar-99 Date Distributed for Review OG Review Completed: y BWOG V WOG V CEOG V BWROG TSTF Comments:

(No Comments)

TSTF Resolution: Approved Date: 06-May-99 6/2/99 Traveler Rev. 2. Copyright (C) 1998, Excel Services Corporation. Use by Excel Services aswclates, utility clients, and the U.S. Nuclear Regulatory Commission is granted. All other use without written permission is prohibited