NRC-99-0082, Application for Amend to License NPF-43,revising TS 3/4.6.1.8 to Allow Continued Operation Until Next Plant Shutdown at Which Time Valve T4803F601 Will Be Repaired

Application for Amend to License NPF-43,revising TS 3/4.6.1.8 to Allow Continued Operation Until Next Plant Shutdown at Which Time Valve T4803F601 Will Be Repaired

ML20212H274
Person / Time
Site:	Fermi
Issue date:	09/24/1999
From:	Oconnor W DETROIT EDISON CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20212H278	List: ML20212H286 NRC-99-0082, Application for Amend to License NPF-43,revising TS 3/4.6.1.8 to Allow Continued Operation Until Next Plant Shutdown at Which Time Valve T4803F601 Will Be Repaired
References
CON-NRC-99-0082 NUDOCS 9910010016
Download: ML20212H274 (13)

Text

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6400 North Dixie IIwy., Neoport, MI 48166 Detroit Edison 10CFR50.92 September 24,1999 NRC-99-0082 U. S. Nuclear Regulatory Commission Attention: Document Control Desk Washington-D C - 20555-0001

References:

1) Fermi 2 NRC Docket No. 50-341 NRC License No. NPF-43

2) Fenni 2 Letter to NRC (NRC-99-0092)

" Request for Enforcement Discretion,"

dated September 24,1999

Subject:

Proposed Exigent Technical Specification Change (License Amendment) to Technical Specification (TS) 3/4.6.1.8, Drvwell and Suppression Chamber Purge System Pursuant to 10CFR50.90, Detroit Edison hereby proposes to amend the Femii 2 Plant Operating License NPF-43, Appendix A, Technical Specifications (TS),3/4.6.1.8.

Reference 2 describes the condition on September 22,1999, when the Nitrogen Inerting Drywell Air Purge Inlet Supply Valve, T4803F601, exceeded the allowable

,ff leakage rate specified by TS Surveillance Requirement 4.6.1.8.2. Technical l

Specification 3.6.1.8 Action (b) in part states " restore the inoperable valve (s) to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />." The

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USNRC NRC-99-0082 Page 2 I

proposed change will allow continued operation until the next plant shutdown at which time valve T4803F601 will be repaired. provides a description and evaluation of the proposed TS change. provides an analysis of the issue of significant hazards consideration using the standards of 10CFR50.92. Enclosure 3 provides the rationale for supporting an exigent change as described in 10CFR50.91(a)(6). Enclosure 4 provides the marked up pages of the existing TS to show the proposed change and a typed version of the affected TS pages with the proposed changes incorporated. The proposed Technical Specifications are also provided in the Improved Technical Specifications (ITS) format since the Fenni 2 ITS are expected to be approved prior to the issuance of this amendment. The ITS formatted TS are structured as a separate Special Operation TS numbered 3.10.8.

Detroit Edison has reviewed the proposed TS changes against the criteria of 10CFR51.22 for environmental considerations. The proposed changes do not involve a significant hazards consideration, nor significantly change the types or significantly increase the amounts of effluents that may be released offsite, nor significantly increase individual or cumulative occupational radiation exposures.

Based on the foregoing, Detroit Edison concludes that the proposed TS changes meet the criteria provided in 10CFR$1.22(c)(9) for a categorical exclusion from the requirements for an Environmental Impact Statement or an Environmental Assessment.

Detroit Edison is requesting that this license amendment be processed as an exigent Technical Specification change in accordance with 10CFR50.91(a)(6) to prevent a plant shutdown. Upon approval, we request a five day irrplementation period.

Upon implementation of this amendment, the next performance of the proposed surveillance requirement (SRs) will be based upon the last performance of the required activity prior to implementation. Note that proposed SR 3.10.8.1 is required by current TS SR 4.6.1.1.b and proposed SR 3.10.8.2, will at the earliest, be due on November 6,1999.

The following two commitments are being made in this letter:

1. A flanged cover will be installed over the opening of T4800F407 by September 28,1999.

2. The valve T4803F601 will be repaired during the next shutdown.

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USNRC NRC-99-0082

. ' Page 3 Should you have any questions or require additional information, please contact Mr. Norman K. Peterson of my staff at (734) 586-4258.

Sincerely, i

lu,0. 0 'C~

r W. T. O'Connor, Jr.

Assistant Vice President, Nuclear Assessment Enclosures cc: A. J. Kugler A. Vegel NRC Resident Office Regional Administrator, Region III Supervisor, Electric Operators, i

Michigan Public Service Commission l

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USNRC NRC-99-0082 Page 4 I, WILLIAM T. O'CONNOR. JR., do hereby aflirm that the foregoing statements are based on facts and circumstances which are true and accurate to the best of my knowledge and belief.-

N b c).

WILLIAM T. O'CONNOR, JR.

Assistant Vice President, Nuclear Assessment MCbt;1999 before me personally

- On this 8 dayof

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appeared William T. O'Connor, Jr.,fein#g first duly sworn and says that he r:xecuted the foregoing as his free act and deed.

) W [W Notary Public ROSALIE A. ARME1TA NOTARY PUBLIC-MONR0ECOUNTY,MI MY COMMISSION EXPIRES 10/11/99

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ENCLOSURE 1 TO NRC-99-0082 FERMI 2 NRC DOCKET NO. 50-341 OPERATING LICENSE NO. NPF-43 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

DRYWELL AND SUPPRESSION CHAMBER PURGE SYSTEM DESCRIPTION AND EVALUATION OF THE PROPOSED CHANGES e

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. to NRC-99-0082 Page1 DESCRIPTION:

Technical Specification Limiting Condition for Operation (LCO) 3.6.1.8, Action (b) requires that with a drywell and suppression chamber purge system supply and/or exhaust isolation valve (s)

' with resilient material seals having a measured leakage rate exceeding the limit of Specification 4.6.1.8.2, restore the inoperable valve (s) to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The proposed Technical Specification change will allow continued operation until the next shutdown when valve T4803F601 is repaired.

Penetration X-26 is in the Drywell Purge and Vent System. The drywell purge and vent lines are 24 inches in diameter. The 24 inch primary containment purge valves are normally maintained closed in MODES 1,2, and 3 to ensure the primary containment boundary is maintained.

- However, these lines are used for inerting and de-inerting the primary containment in conjunction with planned shutdowns that involve entry into the primary containment. The nitrogen purge supply valve for the drywell is 10 inches. In addition,1 inch lines are provided for containment pressure control. T4800F408 connects to the nit ogen supply system. During leak testing, boundary valves are used to isolate T4800F408 from the nitrogen system. A vent valve between T4800F408 and the test boundary valves is used to depressurize and vent the piping outboard from T4800F408.

The Drywell Air Purge penetration (X-26) has three isolation valves that are tested concurrently.

The Inboard Isolation Valve (T4803F601, Butterfly,24 inch, Neles-Jamesbury,24-8222EX MOD. A) and Outboard Isolation Valves (T4800F407, Butterfly,24 inch, Neles-Jamesbury,24-8922EX MOD A, and T4800F408, Butterfly,10 inch, Neles-Jamesbury,10-8926EX MOD. A) comprise the penetration's isolation. The piping configuration is such that the T4800F407 is open directly to secondary containment on one side. This configuration lends itself to a direct visualinspection of the valve seat.

EVALUATION OF THE PROPOSED CHANGE (Sh On September 22,1999, a Local Leak Rate Test (LLRT) was performed for penetration X-26 as required by Surveillance Requirement 4.6.1.8.2. This test is performed by pressurizing between the inboard and outboard isolation valves and measuring the total leakage of the isolation valves.

The penetration exceeded its Technical Specification limit ofless than 0.05 L, (14.87 Standard Cubic Feet per Hour (SCFH)). The penetration leaked at a rate of 26.7 SCFH. Based on direct observation of the T4800F407 and observation of an open % inch vent connection outboard of the T4800F408, test personnel determined that the penetration failed its LLRT due to seat leakage through T4803F601. Subsequently, valve T4803F601 was stroked under light pressure in an attempt to clear the sealing surfaces of any debris. The LLRT was performed again and the leakage from penetration X-26 increased to 82.85 SCFH. Since the only evolution performed between the two LLRTs was the stroking of T4803F601, this subsequent LLRT further L

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Enclosure I to

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substantiated that the leakage is attributable to T4803F601. Visual (utilizing Snoop to aid in leak detection) and audio inspection for leakage at the exposed side of T4800F407 and at the vent connection outboard of T4800F408 by a Level II VT inspector during both tests on September 22,1999 revealed insignificant leakage relative to the measured leakage rates. A Level III VT Inspector confirmed the initial visual inspection and confirmed that T4800F407 and T4800F408

- were an insignificant contributor to the leakage during the second test. A leak detection aid (Snoop) was utilized to aid in leak detection during both tests. - Snoop was applied to the seal of T4800F407 and minor bubbling was observed; it was also used at the vent connection outboard of T4800F408 and no leakage was detected through this valve. This substantiated the assessment that the outboard isolation valves are tight.

4 Review of the LLRT and maintenance records does not indicate an adverse trend for this penetration. Results of previous tests indicate that the penetration leakage has been between approximately 0.6 SCFH and 1.75 SCFH since October of 1998 (four tests). Failure of T4803F601 was not anticipated; and based on the magnitude of the leak and the change in leakage following valve stroke, the likely cause of the leakage is failure of the seal. The seal was replaced during the Sixth Refueling Outage (autumn of 1998).

The combined leakage allowed by Technical Specification 3.6.1.2.b is 0.6 L,. This equates to 178 standard cubic feet per hour (SCFH). The known leakage from containment prior to September 22,1999 was 67.28 SCFH, leaving a margin of 110.72 SCFH. The leakage from i

penetration X-26 is 82.85 SCFH leaving a margin of 27.87 SCFH, when considering the T4803F601 ~as a single boundary valve (i.e., not crediting the outboard valves). The outboard valves will serve to significantly increase this margin, even though leakage was not quantifiable.

The safety basis for this request is the action to isolate the affected penetration using outboard

' isolation valves T4800F407 and T4800F408. While leak rate testing for this penetration can not quantify the leakage of the outboard valves individually, the leakage rate through these isolation devices is believed to be well below the 0.05L, limit, as discussed above. The compensatory action to verify the penetration is isolated on a periodic basis supports the safety function of the valves to isolate following an accident. Reliability of the resilient seals in these valves and the other similar penetrations at Fermi 2 has been high, providing confidence that unexpected material degradation is not occurring in these valves.

The T4803F601 is not a risk significant component in the Level 1 Fermi 2 PSA. The T4803F601 is not an initiator of an event that leads to core damage and does not prevent a core damage event. The T4803F601 has no effect on core damage and is not modeled in the Level 1 Fermi 2

. PSA.

The T4803F601 is a credited component of the Level 2 Fermi 2 PSA. The T4803F601 or the other in line isolation valves must close to isolate penetration X-26. The success criterion is that either inboard or outboard isolation valves in a line must close and remain closed for 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

. to NRC-99-0082 1

Page 3 With the penetration isolated by the outboard isolation valves, failure of the T4803F601 has no effect on the Level 2 PSA results and the success criteria for penetration X-26 is met. Therefore, failure of the T4803F601 is not risk significant.

The T4800F407 and T4800F408 isolation valves are normally closed isolation valves that will be closed and deactivated assuring the valves remain closed until the T4803F601 is repaired. They will be verified closed every 31 days. T4800F407 and T4800F408 will not be cycled until the plant is shutdown to repair the T4803F601.

Because leak rates for the outboard valves can not be individually quantified, a flanged cover will be installed over the opening of T4800F407 by September 28,1999 to provide an additional leakage barrier. This flange will remain in place until the plant is shutdown to correct the penetration leakage. Leak testing of this penetration will be performed at least every 45 days to verify that the 0.6 L,is not exceeded due to additional penetration leakage. This testing will also qualitatively verify the integrity of the outboard isolation barriers (employing the visual and audio inspection techniques and Snoop similar to techniques used on September 22,1999).

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i ENCLOSURE 2TO NRC-99-0082 FERMI 2 NRC DOCKET NO. 50-341 NRC LICENSE NO. NPF-43 REQUEST TO REVISE TECHNICAL SPECIFICATIONS:

10CFR50.92 SIGNIFICANT HAZARDS CONSIDERATION

' Enclost.re 2 to -

. NRC-99-0082 Page1-In accordance with 10CFR50.92, Detroit Edison hes made a detennination that the proposed Lamendment involves no significant hazards consideration. The proposed Technical Specification

- (TS) changes described above do not involve a significant hazards consideration for the following reasons, l'.

The proposed change does not involve a significant increase in the probability or consequences of au accident previously evaluated.

The proposed change revises the accept nce criteria for Drywell Air Purge Penetration X-26 to allow continued operation with inboard isolation valve T4803F601 exceeding the leakage rate.

The T4803F601 is not an initiator of an event or involved in accident initiation sequence.

Therefore, the proposed change does not involve an increase in the probability of an accident.

The T4803F601 or the outboard isolation valves must close to isolate penetration X-26. With the penetration isolated by the outboard isolation valves, failure of the T4803F601 would involve no significant increase in consequences of an accident since the containment function is preserved.

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Therefore, failure of the T4803F601 does not involve an increase in the probability or consequences of an accident.

2.

The proposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

The T4803F601 is an inboard containment isolation valve. The safety function of the valve is to provide for containment penetration X-26 post accident isolation. T4803F601 and two outboard

-isolation valves T4800F407 and T4800F408 comprise the penetrations isolation. The valves

' safety function is to close and remain closed. The outboard isolation valves are normally closed isolation valves that wi;l be closed and deactivated. Therefore, no new or different types of failures or accident initiators are introduced by the proposed change.

3.

The change does not involve a significant reduction in the margin of safety.

Operating with excessive leakage on T4803F601 places additional reliance on T4800F407 and T4800F408, as they would be the single containment barrier. The change includes closing and deactivating the outboard containment isolation valves that are nc mally closed to provide

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assurance the penetration is isolated. Closing and deactivating these valves eliminates the

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potential that any active failure could lead to loss of function. Past leak performance and ongoing periodic leak testing minimize the potential that passive failures would occur for these valves. The change does not involve a new mode of operation or change to the UFSAR transient 3

analyses. Therefore, the proposed change does not involve a significant reduction in the margm ofsafety.

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l ENCLOSURE 3 TO NRC-99-0082 FERMI 2 NRC DOCKET NO. 50-341 OPERATING LI. CENSE NPF-43 RATIONALE FOR SUPPORT OF EXIGENT CHANGE l

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- Enclssure 3 to NRC-99-00821

'Page1 Detroit Edison requests that this license amendment request be processed in an exigent manner as allowed by 10CFR50.91(a)(6) because time does not permit the Commission to publish a Federal

. Register notice' allowing 30 days for prior public comment. Any delay in granting this i

y amendrrient could lead to a plant shutdown. 10CFR50.91(a)(6) requires that license amendments

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N applied for under this criterion be done so in a timely manner. It also requires that the licensee J

explain why the exigent situation occurred and why it could not be avoided. Thejustification for this exigent request is provided below.

. On September 22,' 1999, a Local Leak Rate Test (LLRT) was performed for the Drywell Air

. Purge penetration X-26 as required by Surveillance Requirement 4.6.1.8.2. This test is

. performed by pressurizing between the inboard valve (T4803F601) and two parallel outboard isolation valves (T4800F407 and T4800F408), and measuring the total leakage of the isolation valves. The penetration exceeded its Technical Specification limit ofless than 0.05 L.(14.87 Standard Cubic Feet per Hour (SCFH)). Technical Specification Limiting Condition for Operation (LCO) 3.6.1.8, Action (b) requires that with a drywell and suppression chamber purge system supply and/or exhaust isolation valve (s) with resilient material seals having a measured i

leakage rate exceeding the limit of Specification 4.6.1.8.2, restore the inoperable valve (s) to OPERABLE status within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> or be in at least HOT SHUTDOWN within the next 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and in COLD SHUTDOWN within the following 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

. An extensive investigation and troubleshooting effort by test personnel has determined that the I

penetration failed its LLRT due to seat leakage through the inboard containment isolation valve.

This troubleshooting included stroking the valve suspected ofleaking to clear the sealing surfaces of any debris and a visual and audio inspection by a Level II VT Inspector of the 1

containment outboard isolation valves utilizing Snoop to aid in leak detection. A Level III VT J

Inspector confirmed the initial visual inspection and confirmed that the outboard isolation valves were an insignificant contributer to the leakage during a second test. Review of the LLRT and maintenance records does not indicate an adverse trend for this penetration. Results of the previous four tests indicate the penetration leakage has been approximately 0.6 SCFH and 1.75 SCFH since October 1998. The two outboard isolation valves are normally closed isolation valves that will remain closed and will be deactivated until the inboard isolation valve is repaired. A flanged cover will be installed over the opening of T4800F407. The flanged cover will remain in place and the two outboard isolation valves will not be cycled until the plant is shutdown to correct the penetration leakage. The outboard valves will be verified closed every 31 days and the penetration will be leak tested every 45 days.

LAs descrioed above, the requested exigent treatment of this license amendment could not be avoided.- Detroit Edison has used its best efTorts to correct the penetration leakage concem and to make a timely application for this amendment. This short time frame; however, does not allow the normal public notice and comment period described in 10CFR50.92(a)(2), and still ensure receipt of the license amendment in time to prevent a plant shutdown, w

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j ENCLOSURE 4 TO NRC-99-0082 FERMI 2 NRC DOCKET NO. 50-341 OPERATING LICENSE NPF-43 1

REQUEST TO REVISE TECHNICAL SPECIFICATIONS DRYWELL AND SUPPRESSION CHAMBER PURGE SYSTEM i

Attached is a mark-up of the existing Technical Specifications (TSs), indicating the proposed changes (Part 1) and a typed version of the TSs incorporating the proposed changes with a list of included pages (Part 2). Additionally, attached is the typed version of the new section for the Improved Technical Specifications.