ML20236G958

Forwards Response to Ventilation Filter Testing Program at Plants,As Discussed During STS Conversion Meeting W/Nrc on 980506-07

ML20236G958
Person / Time
Site:	Byron, Braidwood
Issue date:	06/24/1998
From:	Krich R COMMONWEALTH EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9807070029
Download: ML20236G958 (7)

Text

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Commonweahh Edison Company 1400 Opus Place n

Downers Grove, IL 60515-5701 June 24,1998 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D.C. 20555 - 0001 a

Byron Nuclear Power Station, Units 1 and 2 Facility Operating Licenses NPF-37 and NPF-66 N_RC Docket Numbers: 50-454 and 50-455 Braidwood Nuclear Power Station, Units I and 2 Facility Operating Licenses NPF-72 and NPF-77 NRC Docket Numbers: 50-456 and 50-457

Subject:

Additional Information on Improved Technical Specifications Submittal

References:

1. G. Stanley and K. Graesser (Commonwealth Edison) letter to USNRC, " Conversion to the Improved Standard Technical Specifications," dated December 13,1996.

2. Standard Technical Specification Conversion Meeting between Commonwealth Edison and USNRC, May 6th and 7th,1998.

The purpose of this letter is to document the additional information used by the NRC 3

Staffin their review of Section 5.5.11 of the Byron and Braidwood Improved Technical k

Specifications (ITS) submittal (Reference 1). The information provided in the attachment -

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to this letter supports the NRC review of that portion of the ITS identified as Beyond Scope Change (BYS) #15 in the Split Report section of the submittal.

- The BYS #15 issues were discussed during a recent ITS meeting (Reference 2) and involve staff questions on the Ventilation Filter Testing Program at Byron and Braidwood.

9007070029 900624 PDR ADOCK 05000454 P

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A Unicom Company

' LS. NRC June 24,1998 Please address any comments or questions regarding this matter to our Nuclear Licensing Department.

l Sir:cerely, f

R.M. Knch

. Vice President - Regulatory Services

Attachment:

Response to Ventilation Filter Testing Program Questions cc:

Regienal Administrator-RIII

- Byron Project Manager-NRR.

Braidwood Project Manager-NRR Senior Resident Inspector-Braidwood Senior Resident inspector-Byron Oflice ofNuclear Safety-IDNS I

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Attachment Response to Ventilation Filter Testing Program Questions l-G:\\nla\\byrbwdJic48 043. doc a-_.

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What is meant by " general'conformance with" throughout Tech Spec (TS) 5.5.117 Comed response:

General conformance provides the capability for the exceptions identified in the UFSAR' Appendix A, page. A1.52-1 thru 8, Revision 6 - December 1996. These exceptions are identified for Byron and Braidwood and were given to the NRR reviewer, John Segala, at the May 8 meeting on the Beyond Scope Change. The

' Zion ITS submittal, approved by the staffin November of 1997, used "in general

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conformance with" in their program discussion of the.VFTP for their section -

5.5.9.

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2.

Why are you changing to ANSI N510-1980 in TS 5.5.11 rather than ASME N510-1989 and ASTM D3803-1989?

q Comed response:

Comed does plan to review the requirements of ASTM D3803-1989 for possible -

inclusion in the VFTP when the generic letter is received, but our current.

licensing basis (CLB)is to ANSI N510-1980. As identified in the ITS Section 5.0, DOC-A,, various ventilation filter testing requirements of CTS LCOs 3.7.6, 3

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' 3.7.7, and 3.9.12, specify that testing be performed in accordance with Regulatory L

Guide 1.52, Revision 2. The Regulatory Guide references that testing be performed in accordance with the applicable sections of ANSI N510-1975.

However, the CTS Bases for LCOs 3.7.6,3.7.7, and 3.9.12 state that ANSI N510-1980 will be used as the procedural guidance for these surveillance tests.

Consistent with the current licensing basis, the reference to ANSI N510-1980 has l'

been added to the ITS Specification 5.5.11 requirements for performance of '

testing in accordance with Regulatory Guide 1.52, Revision 2.

Comed still has some concerns on volunteering to adopt the draft generic letter i

. recommendations to conform to ASTM D3803-1989 from our current licensing requirements. As pointed out during the review, there are advantages for the industry with some changes in the methods used to calculate the allowance of the test requirements if the new standard were to be adopted. The possibility of

' adopting ASTM D3808-1989 prior to the issuance of the generic letter will be discussed in more detail at the stations prior to final resolution of the VFTP.

Comed will provide a response prior to the issuance of the draft SER.

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j Using a Safety Factor of two, the following are the proposed testing criteria

' assmhing the adoption of the ASTM D3803-89 as the_ lab-testing standard.

Filter Unit Bypass Test Lab Test Accident Analysis '

Allowable Penetration Credit VC Makeup

'.05%

.5%

99 %

LVC Recire Unit 2%*

4%'

90 %

L VA Non Accessible 1%*

4.5%

90%-

FH Building 1%*

10%.

90%,30 M* *

• This is the total filter bypass including the bank bypass and the bypass damper leakage

• • This is the CLB and has not changed from the original SER 3.

TS 5.5.1 l'.a doesn't list an inplace HEPA filter test for the VC recirc housing.

Does this mean there's no HEPA filter in VC recirc housing?

Comed response:

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The current Byron and Braidwood system design for VC does not contain a recire -

HEPA filter.

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, Why is TS 5.5.11.a and 5.5.11.b for VA broken up into "after structural maintenance of the filter housing" and "for reasons other than structural maintenance"? 'Also, why are the flow rates given for 3 banks separate from the flow rates given for the train?.'

Comed response:

Current Licensing Basis. An SER was issued on October 22,1993 approving the -

allowance to only conduct the individual bank flow rates after structural i

. maintenance or modification to the filter housing. In the SER, safety was a major concern in conducting the individual bank flow rate measurements. Since the

, flow distribution for the VA Non-accessible plenums was set during initial

' construction by installation of baffle plates and there are no movable' dampers

controlling flow distribution there is no reason for the flow distribution to change.

As stated in the Byron CTS 4.7.7.g, after any structural maintenance of the HEPA or charcoal filter housing the individual bank flow rates are required, for any other maintenance of the housing, (i.e., painting, etc,) only the system flow rate is requirement is performed.

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. In CLB for the individual plenums / banks, a separate flow rate is measured to verify the plenum operability if any modification or structural change in the filter housing has occurred. Train flow rates are verified if there have been no l

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F structural changes made.

5.

' What is the basis for the bypass values for the VC recirc housing in TS.5.5.11.b?

Comed response:

The values are current licensing basis from the original pages of CTS. The basis of the bypass value is as follows:

i The bypass test allows a 2% bypass, which includes bank leakage and bypass damper leakage.. The charcoal is lab tested to Reg Guide f.52 requirements on 1% penetration.' The bypass of 2% plus penetration of

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1% ensures sufficient margin exists between the decontamination efficiency assumed for the recirculation filter unit of 90% used in the i

control room habitability analysis.

Why is there no ' P test provided in TS 5.5.11.d'for the VC recire housing?

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d Comed response:

CLB from CTS 3/4 7.6. There is no current requirement to test the charcoal absorber for dP since there is no HEPA filter installed in the VC recirc system in series with the charcoal filter.

7.

. How is TS 5.5.11.e performed? Why is it not performed for the VC system?

Comed response:

5.5.1le' is performed by separately measuring the bypass of the filter bank and the

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i bypass damper and summing the two to determine the total bypass leakage.

For the Byron and Braidwood system design, there is no bypass damper around the VC makeup filters; all makeup is through the filter arrangement.-

The potential bypass around the VC recirc system is on the charcoal filter system used in the makeup mode. This bypass test is completed in 5.5.11.b.

'I The control room recirculation filter does possess a bypass damper and filter i

bank, however the ductwork configuration allows a bypass test to be performed

. which includes both the bank leakage and the bypass damper leakage.

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< *': Does the heater test in TS 5.5.11.f. apply to.both VC makeup and the VC recire? '

L How can you justify performing the lab test at 70% relative humidity in TS

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5.5.11.c for VA charcoal when there is no heater test provided in TS 5.5.11.f for.

_ the VA system -

... Comed response:

The heater test for the VC system 'only applies in the makeup mode' of operation.

for each train.-

Byron and Braidwood have a calculation / evaluation to show that the humidity will not exceed 70% relative humidity (RH) in the Auxiliary Building. During.

. initial licensing of the plant, the NRC reviewed and accepted the analysis which E

demonstrated that the RH Level upstream on the non accessible filter units would

be less thm 70% at all times and that it was acceptable to test the carbon at 30 C and 70% RH.

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