ML20207D585

Submits Info Re Partial Fulfillment of License Conditions Placed on Amend 101,which Approved Use of Ten Exceptions for 24 Months Subject to Listed App C Conditions.Util Will Submit Second Rept to Obtain Approval for Continued Use

ML20207D585
Person / Time
Site:	Monticello
Issue date:	05/25/1999
From:	Day B NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9906040011
Download: ML20207D585 (8)

Text

I Northem States Power Company Monticello Nuclear Generating Plant 2807 West Hwy 75 Monticello. Minnesota 55362-9637 May 25,1999 10 CFR Part 50 Section 50.71 (a)

U S Nuclear Regulatory Commission Attn: Document Control Desk -

Washington, DC 20555 MONTICELLO NUCLEAR GENERATING PLANT Docket No. 50-263 License No. DPR-22 Partial Fulfillment of License Conditions Placed on Amendment 101 l I

Reference 1. Letter from Craig A. Schibonski, NSP, to NRC Document Control Desk,  !

" Revision Two To License Amendment Request Dated July 26,1996 Reactor Coolant Equivalent Radiciodine Concentration And Control' Room Habitability," dated June 19,1998.

I As an attachment to the above Reference 1 NSP submitted " Exhibit F - EFT System Commitment and ASME N510-1989 Testing Exceptions." In this exhibit NSP identified ten current requirements for filter testing which it found potentially impractical for the existing Monticello Emergency Filtration Testing (EFT) system. In response, the NRC issued Amendment 101 to the Monticello license which approved use of the ten exceptions for 24 months subject to the following Appendix C conditions:

Conduct an independent evaluation of the testing methodology and the testing configuration of the EFT [ emergency filtration testing] system by HEPA and charcoal filter testing expet1s.

This evaluation shallinclude review of the exceptions to the ASME N510-1989 testing standards listed in Exhibit F of NSP's June 19,1998, letter. The evaluation shall be reported to the NRC. (The implementation date for this condition is "Within 9 months of the date of issuance of Amendment No.101.")

Initiate appropriate modifications to the EFT system to comply with the ASME N510-1989 testing standard or obtain NRC approval for continued use of the exceptions. (The l )

implementation date for this condition is *Within 24 months of the date ofissuance of I Amendment No.101 ')

NSP engaged NUCON to perform the independent evaluation. Attached is Exhibit F of the June I

19,1998 letter, annotated with the NUCON evaluation and the NSP response, to address each u i JM.lCENSE\ License App C\ EFT I,c cond #1. doc I 9906040011 990525 PDR ADOCK 05000263 P PDR l

1 of the ten testing e.vceptions. Three of the exceptions (items 3,4, and 5 of Exhibit F) can be eliminated because NSP currently complies with these sections of N510-1989. Three of the exceptions (items 6,8, and 10 of Exhibit F) can be eliminated because compliance can be <

achieved with reasonable modifications to the Monticello EFT system. Three of the exceptions I (items 1,2, and 9 of Exhibit F)will be retained because N510 compliance would require major re-design and modification of the existing Monticello facility. A modification will be performed which may eliminate the need for one exception (item 7 of Exhibit F.) This must be re-evaluated following completion of the modification.  !

l NSP considers this submittal to complete the requirements of the first licerise condition cited 1 above. We are proceeding with the modifications and testing so that they are completed within j the 24 month interval. We will submit a second report in sufficient time to obtain NRC approval i for continued use of the remaining exceptions within the 24 month interval. This report will also address the results of the injection point modification (item 7 of Exhibit F.) ,

This letter contains no new NRC commitments, nor does it modify any prior commitments. j Please direct any questions on this matter to Marcus H. Voth, Licensing Project, at (612) 271-5116.

Byron Day i Plant Manager Monticello Nuclear Generating Plant ,

c: Regional Administrator-Ill, NRC  ;

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NRR Project Manager, NRC Resident Inspector, NRC j State of Minnesota Attn: Steve Minn i l

Attachments: Affidavit to the US Nuclear Regulatory Commission Exhibit F - EFT System Commitment and ASME N510-1989 Testing Exceptions (Annotated version of Exhibit F as it originally appeared in Reference 1)

UNITED STATES NUCLEAR REGULATORY COMMISSION i .

NORTHERN STATES POWER COMPANY MONTICELLO NUCLEAR GENERATING PLANT DOCKET NO. 50-263 Submittal of Information Provided in Partial Fulfillment of License Conditions Placed on Amendment 101 Northern States Power Company, a Minnesota corporation, hereby submits a letter dated May 25, 1999 entitled Partial Fulfillment of License Conditions Placed on Amendment 101 intended to fulfill the requirements of the first of two license conditions issued with Amendment 101 of license DPR-22 found in Appendix C, Additional Conditions- Facility Operating License No. DPR-22.

This letter contains no restricted or other defense information.

NORTHERN STATES POWER COMPANY By J 2/m h, yron'DIfag

@lant P Manager Monticello Nuclear Generating Plant On this A 5 D day of AV / 9 99 before me a notary public in and for said County, personally appeared Byr'on D. Day, Plant Manager, Monticello Nuclear Generating Plant, and being first duty sworn acknowledged that he is authorized to execute this document on behalf of Northern States Power Company, that he knows the contents thereof, and that to the best of his knowledge, information, and belief the statements made in it are true and that it is not interposed for delay.

CAILtAA4_ ' ~

Marcus H. Voth Notary Public - Minnesota Wright County My Commission Expires January 31,2000 I MARCU8 H. VOTH l ! NOTMtYPUKIC MINNESOTA; i

... $ M _ D 1_ D 81' N .. .. .

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Exhibit F

. . EFT System Commitment and ASME N510-1989 Testing Exception j l'

(Annotated version of Exhibit F as it originally appeared in Reference 1)

Commitment Within 9 months of the date of the approval of this amendment, NSP will conduct an

. Independent evaluation of the testing methodology and system testing configuration of the Emergency Filtration (EFT) system by HEPA and charcoal filter testing experts. All of the exceptions to the testing standards listed below will be evaluated. The results of this review will be reported to the staff.

ASME N510-1989 Testing Exceptions

1. Section 5.5.1 of ASME N510-1989 Section 5.5.1 of ASME N510-1989 provides guidance for visualinspection of the air treatment system.

NSP Exception NSP performs a visual Inspection of applicable items from Section 5.5.1, NSP performs a visual inspection by procedure, but many of the standard's inspections items are not applicable to the Monticello EFT system. Examples of items that are not applicable to Monticello include:

1) dovetail type access gaskets with a seating surface suitable for a knife edge seal, and 2) shaft seals.

NUCON Evaluation and NSP response NUCON agrees that many of the checklist items found in N510 do not apply to the EFT l system since it is a serpentine type of design not addressed by ASME N509. In addressing the specific examples of incompatibility between the Monticello EFT installation and N510 requirements, NUCON recommends that replacement gaskets should have a dovetail design. NSP agrees that as parts are replaced, such testability Improvements should be considered. ,

l Exception #1 will be retained, since the visual checklist contains items which are not applicable to the EFT system.

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2. Section 6.2.2 and Table 1 of ASME N510-1989 l Section 6.2.2 and Table 1 of ASME N510-1989 state that a housing leak test shall be performed every 10 years. ,

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NSP Exception l ' This test is not performed at Monticello. The EFT system at Monticello was built to be tested to l . ANSI /ASME N510-1980 which does not require these tests to be performed periodically. No provisions were provided to accommodate this test. The entire EFT housing is contained within the protective envelope supplied by the system, and any leakage into the housing would be filtered air. Periodic performance of a test that verifies the ability to maintain the control room envelope at a positive pressure is an adequate demonstration of system leak integrity.

NUCON Evaluation and NSP response NUCON agrees that the housing leak test would be very difficult to perform, given the EFT system design. NUCON states an acceptable alternative would be to perform a

smoke test on the housing upon completion of periodic in-place filter testing to detect any.Inleakage. NSP has incorporated the smoke test into EFT in-place filter testing procedures.

Exception #2 will be retained. The housing smoke test provides an acceptable alternative to detect housing inleakage.

3. Section 7.1 of ASME N510-1989 Section 7.1 of ASME N510-1989 recommends a mounting frame pressure leak test to verify the absence of leaks through seal welds of the HEPA filter and adsorber frames, and between the frames and housings be performed.

NSP Exception This test is not performed at Monticello. Leaks of this nature are detected by the visual inspection test or the in-place filter test, and credit is taken for these tests as allowed by the standard.

NUCON Evaluation and NSP response NUCON states that per N510-1989 the mounting frame pressure leak test is an optional test which would normally only be done during acceptance testing. NSP agrees that the l

test is optional, noting that Table 1 of N510-1989 states "It is left up to the owner to l

determine whether a mounting frame leak test is warranted based upon the visual examination."

Exception #3 will be eliminated since NSP does comply with Section 7.1 of N5101989.

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4. Section 8.5.1.4 of ASME N510-1989 Section 8.5.1.4 of ASME N510-1989 requires that a housing component pressure drop airflow i test be performed which requires that maximum pressure drops across each of the components  !

be simulated. The unit is run at this maximum pressure drop across the system, and adequate airflow is ensured.

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NSP Exception i This test is not performed at Monticello. The EFT system was designed to be tested to the ANSI /ASME N510-1980 standard which does not require that this test be performed l periodically. The system at Monticello contains a low flow trip. If airflow is too low through the l system due to debris loading of the filters, the running train will automatically trip, and the  ;

standby train will start.

NUCON Evaluation and NSP response l NUCON states that per N510-1989 the pressure drop airflow test is required only during acceptance testing and after major modification. NSP agrees that periodic pressure drop airflow tests are not required by the standard.

Exception #4 will be eliminated since NSP does comply with Section 8.5.1.4 of N510-1989.

5. Section 8.5.2.2 of ASME N510-1989 Section 8.5.2.2 of ASME N510-1989 requires a periodic airflow distribution test through the adsorber banks.

NSP Exception This test is not performed at Monticello. Monticello's EFT system was designed to be tested to i the ANSI /ASME N510-1980 standard which does not require this test be performed periodically. No provisions were made in the design of the Monticello EFT to perform this test periodically.

NUCON Evaluation and NSP response NUCON states that per N510-1989 the airflow distribution test is required only during acceptance testing and after major modification. NSP agrees that periodic airflow distribution tests are not required by the standard.

Exception #5 will be eliminated since NSP does comply with Section 8.5.2.2 of N510-1989.

6. Section 10.3 of ASME N510-1989 Section 10.3 of ASME N510-1989 states that sample points for DOP sampling shall be I downstream of a fan, or downstream sample manifolds shall be qualified per ASME N509.

NSP Exception At Monticello, the downstream sampling is performed upstream of the fan using a single injection point. No shaft seals are installed on the system's fans, therefore sampling j 3 l 1

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i downstream of the fan would obtain a diluted air sample. Section 10.3 of the ANSI /ASME N510-1980 standard, which the EFT System was originally designed to, does not require the

' use of a sampling manifold. No provisions were made in the design of the Monticello EFT for l sampling manifolds. I I

l NUCON Evaluation and NSP response NUCON agrees that testing downstream of a known dilution source is not acceptable.

NUCON recommends use of temporary sample manifolds for downstream sampling, I which would be installed for testing and removed for operation. NSP agrees with )

NUCON's recommendation and will obtain and qualify manifolds for in-place testing. l Exception #6 will be eliminated following incorporation of manifolds into the testing j program.

7. Section 10.5.8 of ASME N510-1989 l l

Section 10.5.8 of ASME N510-1989 states that upstream and downstream DOP concentrations are repeated until readings within +/- 5 % of respective previous readings are obtained. The final set of readings is then used to calculate penetration.

NSP Exception At Monticello, the readings are taken until the concentrations are within +/- 10% and the highest penetration reading is conservatively used with a minimum of three readings taken.

Because of the injection point location for the Monticello EFT system, it is difficult to consistently achieve +/- 5% between readings.

NUCON Evaluation and NSP response  ;

NUCON recommends that the injection port be relocated or that injection manifolds be evaluated to provide better mixing of the challenge agent. NSP agrees with NUCON's recommendation and will incorporate either qualified new injection ports or injection ,

manifolds into the testing program. This exception will then be reevaluated and i eliminated if the +/-5 % criterion can be met.

Exception #7 will be eliminated if the +/-5 % criterion can be met following incorporation of manifolds and/or new injection ports into the testing program.

8. Section 11.3 of ASME N510-1989 Section 11.3 of ASME N510-1989 states that sample points for halide challenge gas shall be downstream of a fan or downstream sample manifolds shall be qualified per ASME N509.

NSP Exception See item 6 above.

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NUCON Evaluation and NSP response See item 6 above. Exception #8 will be eliminated following incorporation of manifolds into the testing program.

9. Section 11.4 of ASME N510-1989 Section 11.4 of ASME N510-1989 states that R-11 is the preferred test gas with R-112 or R-112A as acceptable alternatives.

NSP Exception NSP reserves the ability to use alternate test gases that are found to be acceptable alternatives by the industry. Monticello currently employs R-11 as the test gas; however, environmental concerns regarding the use of such halide gases may result in use of these gases not being feasible in the future.

NUCON Evaluation and NSP response NUCON and NSP agree that this exception is reasonable.

Exception #9 will be retained, since use of the specified test gas (R-11) may be restricted in the future.

10. Section 11.5.8 of ASME N510-1989 Section 11.5.8 of ASME N510-1989 states that when a housing contains more than one bank )

of adsorbers in series, the halide gas test shall be repeated for each bank. I 1

NSP Exception 1 At Monticello, the two adsorber banks are tested as a single unit. This requirement was not present in A.NSI/ASME N510-1980, which the EFT System was designed to, and a qualified injection manifold between the two banks was not provided.

NUCON Evaluation and NSP response NUCON recommends use of temporary injection / sample manifolds to test the adsorber banks individually, which would be installed for testing and removed for operation.

NSP agrees with NUCON's recommendation and will obtain and qualify manifolds for in-place testing.

Exception #10 will be eliminated following incorporation of manifolds into the testing program.

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