W3F1-2010-0018, Request for Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection

Request for Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection

ML100550134
Person / Time
Site:	Waterford
Issue date:	02/22/2010
From:	Murillo R Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
W3F1-2010-0018
Download: ML100550134 (9)

Text

Entergy Operations, Inc.

17265 River Road Killona, LA 70057-3093 Tel 504-739-6715 Fax 504-739-6698 rmurill@entergy.com Robert J. Murillo Licensing Manager Waterford 3 W3F1-2010-0018 February 22, 2010 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001

SUBJECT:

Request for NRC Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection Waterford Steam Electric Station, Unit 3 Docket No. 50-382 License No. NPF-38

Dear Sir or Madam:

Pursuant to 10CFR50.55a(a)(3)(i), Entergy Operations, Inc. (Entergy) requests NRC approval to use an alternative to the requirements of the American Society of Mechanical Engineers (ASME) Code requirement to perform VT-2 visual examination. As documented in Attachment 1, this request pertains to portions of two Chemical Volume Control System (CVCS) lines that are enclosed in a vertical pipe chase.

Entergy proposes to perform the VT-2 visual examination during an outage with no pressure or temperature requirements. Entergy believes that the proposed alternative provides reasonable assurance that any through wall leakage occurring during the operating cycle will be found. As such, Entergy believes the proposed alternative provides an acceptable level of quality and safety.

To support the Waterford 3 Spring 2011 re'fueling outage, Entergy requests approval of the proposed alternative by February 22, 2011. Attachment 1 provides Entergy's request for relief including the basis for the proposed alternative. This letter contains one new commitment as provided in Attachment 2.

/

If you have any questions or require additional information, please contact me at 504-739-6715.

7S

cerely, RJMAWJS Attachments: 1. Request for NRC Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection

2.

List of Regulatory Commitments 4 u47

W3F1-2010-0018 Page 2 cc:

Mr. Elmo E. Collins, Jr.

Regional Administrator U. S. Nuclear Regulatory Commission Region IV 612 E. Lamar Blvd., Suite 400 Arlington, TX 76011-4125 NRC Senior Resident Inspector Waterford Steam Electric Station Unit 3 P.O. Box 822 SKillona, LA 70057 U. S. Nuclear Regulatory Commission Attn: Mr. N. Kalyanam Mail Stop 08B13 Washington, DC 20555-0001 Wise, Carter, Child & Caraway ATTN: J. Smith P.O. Box 651 Jackson, MS 39205 Winston & Strawn ATTN: N.S. Reynolds 1700.K Street, NW Washington, DC 20006-3817 Morgan, Lewis & Bockius LLP ATTN: T.C. Poindexter 1111 Pennsylvania Avenue, NW Washington, DC 20004 Louisiana Department of Environmental Quality Office of Environmental Compliance Surveillance Division P. O. Box 4312 Baton Rouge, LA 70821-4312 American Nuclear Insurers Attn: Library 95 Glastonbury Blvd.

Suite 300 Glastonbury, CT 06033-4443

Attachment to W3F1-2010-0018 Request for NRC Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection Relief Request W3-ISI-017 to W3F1-2010-0018 Page 1 of 4 Entergy Operations, Inc.

Waterford Steam Electric Station, Unit 3 Request for Alternative W3-1SI-01 7 Request for NRC Alternative to ASME IWA-5211 Regarding Chemical Volume Control System Pipe Visual Inspection Components/ Numbers:

Line 2CH2-60 A/B and 2CH2-53 A/B in the vertical pipe chase.

Code Class:

2

References:

ASME Section Xl, 2001 Edition, 2003 Addenda, Table IWC-2500-1 ASME Section XI, 2001 Edition, IWA-5211 Examination Category:

C-H Item Numbers:

C7.10

==

Description:==

Periodic system leakage test of piping contained in a vertical pipe chase.

Unit/Inspection Interval Waterford 3 third (3 rd) 10-year interval Applicability:

I.

Code Requirement(s)

ASME Section XI, Table IWC-2500-1, Examination Category C-H,. Item Nos.

C7.10 requires the subject lines to be VT-2 visually examined during a system leakage test each inspection period. IWA-521 1 requires that the visual examination be performed while the item being tested is at normal operating pressure.

I1. Requested Alternative Pursuant to 10 CFR 50.55a(a)(3)(i), Entergy requests authorization to perform a VT-2 visual examination of the subject lines and the surrounding areas once each period during a refueling outage with no pressure/temperature requirements.

This alternative will be performed in lieu of the requirements of IWA-521 1 for the subject lines inside the vertical pipe chase. This examination will be performed prior to any maintenance being performed inside the pipe chase or on the subject lines.

to W3F1-2010-0018 Page 2 of 4 Ill. Basis for Relief ASME Section Xl IWA-5213(a) requires that a non-insulated component be at system operating pressure for 10 minutes and a VT-2 visual examination performed while at pressure. IWA-5241(b) allows an examination of the surrounding area (including floor areas or equipment surfaces located underneath the components) for evidence of leakage for non-insulated components that are inaccessible for direct VT-2 visual examination. IWA-5245 allows the pressure to be lowered to a level corresponding to a temperature of 200 OF after the required hold time but prior to the VT-2 visual examination for systems that operate above 200 OF.

Therefore, the code allows a non-insulated, non-borated standby system to be VT-2 examined by inspecting surfaces below the piping after being at test pressure for 10 minutes. In addition, the Code allows owners to perform this VT-2 examination after the pressure has been reduced to a pressure corresponding to a temperature of 200 OF.

Letdown line 2CH2-60 A/B and charging line 2CH-53 A/B are located in a pipe chase (the vertical L-wall pipe chase) that is part of a Controlled Ventilation Area System (CVAS) boundary. Waterford 3 utilizes the CVAS to provide high efficiency particulate filtration and iodine adsorption in the controlled ventilation area. The system must exhaust air from the controlled ventilation area at a rate required to create and maintain a negative pressure below 0.25-inch water gage relative to the surrounding areas. CVAS is composed of two independent trains, each capable of creating and maintaining the 0.25-inch water gage negative pressure. (See further discussions of CVAS operation in Waterford 3 Final Safety Analysis Report Section 6.5.1)

The Waterford 3 Technical Specification (TS) 3/4.7.7 provides the OPERABILITY requirements for CVAS. TS Section 4.7.7.d.2 requires that each CVAS train be capable of maintaining a negative pressure of 0.25-inch water gage. In the event this condition cannot be met, TS requires the associated train to be declared INOPERABLE and restored to OPERABLE status within 7 days or the plant must be placed in HOT STANDBY within the next six hours and in COLD SHUTDOWN within the following 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br />. With both trains INOPERABLE, TS requires entry into TS Limiting Condition for Operation (LCO) 3.0.3. LCO 3.0.3 requires the appropriate LCO to be met within one hour or the plant must be in HOT STANDBY within the next six hours, HOT SHUTDOWN with the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and COLD SHUTDOWN with the subsequent 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

Temporary access to the pipe chase is provided through special block-out sections consisting of multiple layers of solid concrete blocks. Except for the temporary access block-outs, the pipe chase is totally enclosed by reinforced concrete walls. The blocks are mortared in. place. The block-out sections to W3F1-2010-0018 Page 3 of 4 penetrate into the CVAS boundary. Removing the block wall during normal operation (Modes 1, 2, 3, or 4) violates the CVAS boundary, placing both CVAS trains in INOPERABLE status in accordance with TS. Approximately six days are required to remove and re-install the block wall.

The subject piping is inaccessible during normal operation without deliberate entry into a TS action statement requiring plant shutdown. When the pipe is accessible during plant shutdown (Modes 5 and 6), the system cannot be operated to obtain the required test conditions. Therefore, Entergy proposes the alternative described in Section I1. Entergy believes the alternative provides an acceptable level of quality and safety based on the following:

1) If leakage from the subject sections of charging and letdown piping were to occur, it would show up as unidentified leakage in the reactor coolant system inventory balance. Operations personnel perform this balance at least once every 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> per TS Surveillance 4.4.5.2.1 in Modes 1, 2, 3, and 4. The TS limit for unidentified leakage is 1 gpm unidentified leakage. If the 1 gpm TS limit is exceeded, TS requires a plant shutdown if leakage is not restored below the limit within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. In addition, administrative procedural controls are in place that would require a leakage investigation and shutdown evaluation well before the TS 1 gpm limit was reached.

2) These two non-insulated sections of piping in the vertical pipe chase do not see leakage test conditions during Modes 5 and 6. However, they do experience significant service while at normal plant conditions during plant operation. Records research has shown that these two lines have been in service for more than 20,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> during the last ten year period.

3) The subject charging and letdown lines are part of the Chemical Volume Control System (CVCS). This system is borated for the purpose of controlling reactivity. The boric acid provides a chemical marker that leaves behind a white stain when very small amounts of leakage occur. As any postulated leakage would occur over a period of time, boric acid residue would build, allowing discovery of very small leaks.

4) The time at pressure since the last VT-2 visual examination is in excess of 20,000 hours0 days <br />0 hours <br />0 weeks <br />0 months <br />, far greater than the Code-required 10 minute hold time. Since these lines are borated and non-insulated, sufficient time is available for boric acid to build up on the piping or adjacent surfaces. A subsequent VT-2 visual examination, after the block wall has been removed and prior to any maintenance activities, is adequate to discover any leakage.

to W3F1-2010-0018 Page 4 of 4 IV. Conclusion 10CFR50.55a(a)(3) states:

Proposed alternatives to the requirements of (c), (d), (e), (f), (g), and (h) of this section or portions thereof may be used when authorized by the Director of the Office of Nuclear Reactor Regulation. The applicant shall demonstrate that:

(i) The proposed alternatives would provide an acceptable level of quality and safety, or (ii) Compliance with the specified requirements of this section would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety.

As discussed in Section III above, the subject lines are in service for long periods of time between outages. These periods of service are many factors of time larger than the Code required 10 minute hold time. These long periods of time in addition to the system being borated would provide positive indication of leakage regardless of system pressure. Entergy believes that performing the proposed alternative will provide a better indication of the condition of the lines than the minimum Code requirement and provides an acceptable level of quality and safety. Therefore, we request authorization to perform the requested alternative to the Code requirement pursuant to 10CFR50.55a(a)(3)(i).

W3F1-2010-0018 List of Regulatory Commitments to W3F1-2010-0018 Page 1 of 1 List of Regulatory Commitments The following table identifies those actions committed to by Entergy in this document.

Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.

TYPE SCHEDULED COMPLETION DATE COMMITMENT (Check one)

(If Required)

ONE-TIME CONTINUING ACTION COMPLIANCE Following NRC approval, Entergy will X

Prior to testing incorporate the alternative into the during the 2011 Waterford 3 Inservice Inspection Plan. This Refuel 17 Outage incorporation will also ensure the examination will be performed prior to any maintenance being performed inside the pipe chase or on the subject lines.