Text

Forwards Response to NRC Request for Clarification of Relief Requests Submitted on 990212,requesting Relief from Performing Hydrostatic Testing for Certain Small Diameter Class 1,RCS Pressure Boundary Connections
	ML18152B437
Person / Time
Site:	Surry, North Anna
Issue date:	06/24/1999
From:	Hartz L; VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:	; NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
	99-029A, 99-29A, NUDOCS 9906290227
	Download: ML18152B437 (14)
	v • d • e

.(

e e VIRGINIA ELECTRIC AND POWER COMPANY RICHMOND, VIRGINIA 23261 June 24, 1999 United States Nuclear Regulatory Commission Serial No. 99-029A Attention: Document Control Desk NL&OS/GDM RO Washington, D.C. 20555 Docket Nos. 50-280, 281 50-339 License Nos. DPR-32, 37 NPF-7 Gentlemen:

VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION UNITS 1 AND 2 NORTH ANNA POWER STATION UNIT 2 ASME SECTION XI RELIEF REQUESTS In our letter dated February 12, 1999 (Serial No.99-029) Virginia Electric and Power Company requested relief from performing hydrostatic testing for certain small diameter

(~ 1 inch), Class 1, reactor coolant system (RCS) pressure boundary connections.

During review of the relief requests, the NRC requested clarification of certain points in the basis for the relief. This letter provides the requested clarification and includes an expanded discussion of the basis for the relief requests. Certain ASME Code references have also been corrected.

These clarifications and the Code reference corrections are provided in the revised relief requests. Revised relief request SPT-17 for North Anna Unit 2 is provided in Attachment 1. -Revised relief request no. 13 for Surry Unit 1 and no. 7 for Surry Unit 2 are provided in Attachments 2 and 3, respectively. These revised relief requests supercede the relief requests provided in our February 12, 1999 letter in their entirety.

If you have any questions concerning these requests, please contact us.

Very truly yours,

~~(/ L. N. Hartz Vice President - Nuclear Engineering and Services Attachments

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No new commitments are included in this correspondence.

cc: U. S. Nuclear Regulatory Commission Region II Atlanta Federal Center 61 Forsyth St., SW, Suite 23T85 Atlanta, Georgia 30323 Mr. R. A. Musser NRC Senior Resident Inspector Surry Power Station Mr. M. J. Morgan NRC Senior Resident Inspector North Anna Power Station Mr. R. Smith Authorized Nuclear Inspector Surry Power Station Mr. M. Grace Authorized Nuclear Inspector North Anna Power Station

ATTACHMENT 1 ASME SECTION XI RELIEF REQUEST NO. SPT-17 NORTH ANNA POWER STATION UNIT 2

i North Anna Power Station Unit 2 Second 10 Year Interval Request for Relief Number SPT-17 I. IDENTIFICATION OF COMPONENTS Approximately 20, small diameter (~ 1 inch), Class 1, reactor coolant system (RCS) pressure boundary vent and drain, sample, and instrumentation connections.

II. IMPRACTICABLE CODE REQUIREMENTS Section XI, 1986 Edition, Examination Category B-P, Items 815.51 and 815.71 require system hydrostatic testing and associated VT-2 visual examination of all Class 1 pressure retaining piping and valves.

Ill. ISi BASIS FOR RELIEF REQUEST These piping segments are equipped with valves, or valve and flange, that provide for double isolation of the reactor coolant system (RCS) pressure boundary. These components are generally maintained closed during normal operation and the piping outboard of the first isolation valve is, therefore, not normally pressurized. The proposed alternative provides an acceptable level of safety and quality based on the following:

1. ASME Section XI Code, paragraph IWA-4400, provides the requirements for hydrostatic pressure testing of piping and components after repairs by welding to the pressure boundary. IWA-4400(b)(5) excludes component connections, piping, and associated valves that are 1 inch nominal pipe size and smaller from the hydrostatic test. Consequently, hydrostatic testing and the associated visual examination of these _:: 1 inch diameter RCS vent/drain/sampling connections once each 10-year interval is unwarranted considering that a repair weld on the same connections is exempted by the ASME XI Code.

2. The non-isolable portion of the RCS vent and drain connections will be pressurized and visually examined as required. Only the isolable portion of these small diameter vent and drain connections will not be pressurized.

3. All piping connections are typically socket-welded, and the welds received a surface examination after installation. The piping and valves are nominally heavy wall (schedule 160 pipe and 1500# valve bodies). This piping and valve/flanges are towards the free end of a cantilever configuration (stub end isolated by either a valve or a flange). There is no brace or support for this portion of the pipe.

Consequently, this portion does not experience any thermal loading. This portion of the line is isolated during normal operation and does not experience pressure

loading unless there is a leak at the first isolation valve. The valves do not have an extended operator, so the rotational accelerations at the valve do not produce significant stress. Since the lines are designed to the Code, the stresses towards the free end of the cantilever due to every other type of loading are only a small fraction of the applicable Code allowable. As a result, this portion of the lines is not subjected to high stress or high intensity cyclic loading.

The Technical Specifications (TS) require RCS leakage monitoring (TS 4.4.6.2.1) during normal operation. Should any of the TS limits be exceeded, then appropriate corrective actions, which may include shutting the plant down, are required to identify the source of the leakage and restore the RCS boundary integrity.

During the 1998 North Anna Unit 1 refueling outage similar piping segments were pressurized by removing a flange and connecting a test rig. A majority of these piping segments are located in close proximity to the RCS main loop piping thus requiring personnel entry into high radiation areas within the containment. The dose associated with this testing was 1.5 man-Rem.

IV. ALTERNATE PROVISIONS As an alternative to the Code required hydrostatic test of the subject Class 1 reactor coolant system pressure boundary connections the following is proposed:

1. The RCS vent, drain, instrumentation, and sample connections will be visually examined for leakage, and any evidence of past leakage, with the isolation valves in the normally closed position each refueling outage during the ASME XI Class 1 System Leakage Test (IWB-5221).

2. The RCS vent, drain, instrumentation, and sample connections will also be visually examined with the isolation valves in the normally closed position during the 10-year ISi pressure test (IWB-5222 and Code Case N-498-1 ). This examination will be performed with the RCS at nominal operating pressure and at near operating temperature after satisfying the required 4-hour hold time.

In addition, during modes 1 through 4 the RCS will be monitored for leakage at the following frequency pursuant to TS requirements:

1. Every 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months , during steady state operation, the reactor coolant system leak rate will be monitored to assure the limit of one gallon per minute unidentified leakage is maintained.

2. Every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months the containment atmosphere particulate radioactivity will be monitored.

The proposed alternative stated above will ensure that the overall level of plant quality and safety will not be compromised.

V. IMPLEMENTATION SCHEDULE This alternative to Code requirements will be implemented upon receiving NRG approval for the remainder of the second ten-year inspection interval.

By a letter dated September 3, 1998 the NRG approved a similar relief request for the Edwin I. Hatch Plant, Units 1 and 2.

ATTACHMENT 2 ASME SECTION XI RELIEF REQUEST NO. 13 SURRY POWER STATION UNIT 1

Surry Power Station Unit 1 Third Ten Year Interval Request for Relief Number 13 I. IDENTIFICATION OF COMPONENTS Approximately 20, small diameter (~ 1 inch), Class 1, reactor coolant system (RCS) pressure boundary vent and drain, sample, and instrumentation connections.

II. IMPRACTICABLE CODE REQUIREMENTS Section XI, 1989 Edition, Examination Category B-P, Items B15.51 and B15.71 require system hydrostatic testing and associated VT-2 visual examination of all Class 1 pressure retaining piping and valves.

Ill. ISi BASIS FOR RELIEF REQUEST These piping segments are equipped with valves, or valve and flange, that provide for double isolation of the reactor coolant system (RCS) pressure boundary. These components are generally maintained closed during normal operation and the piping outboard of the first isolation valve is, therefore, not normally pressurized. The proposed alternative provides an acceptable level of safety and quality based on the following:

1. ASME Section XI Code, paragraph IWA-4700, provides the requirements for hydrostatic pressure testing of piping and components after repairs by welding to the pressure boundary. IWA-4700(b)(5) excludes component connections, piping, and associated valves that are 1 inch nominal pipe size and smaller from the hydrostatic test. Consequently, hydrostatic testing and the associated visual examination of these _::. 1 inch diameter RCS vent/drain/sampling connections once each 10-year interval is unwarranted considering that a repair weld on the same connections is exempted by the ASME XI Code.

2. The non-isolable portion of the RCS vent and drain connections will be pressurized and visually examined as required. Only the isolable portion of these small diameter vent and drain connections will not be pressurized.

3. All piping connections are typically socket-welded, and the welds received a surface examination after installation. The piping and valves are nominally heavy wall (schedule 160 pipe and 1500# valve bodies). This piping and valve/flanges are towards the free end of a cantilever configuration (stub end isolated by either a valve or a flange). There is no brace or support for this portion of the pipe.

Consequently, this portion does not experience any thermal loading. This portion of the line is isolated during normal operation and does not experience pressure

loading unless there is a leak at the first isolation valve. The valves do not have an extended operator, so the rotational accelerations at the valve do not produce significant stress. Since the lines are designed to the Code, the stresses towards the free end of the cantilever due to every other type of loading are only a small.

fraction of the applicable Code allowable. As a result, this portion of the lines is not subjected to high stress or high intensity cyclic loading.

The Technical Specifications (TS) require RCS leakage monitoring (TS Table 4.1-2A, Item No. 10) during normal operation. Should any of the TS limits be exceeded, then appropriate corrective actions, which may include shutting the plant down, are required to identify the source of the leakage and restore the RCS boundary integrity.

The required pressure testing was recently performed during the North Anna Unit 1 1998 refueling outage. Similar piping segments were pressurized by removing a flange and connecting a test rig. A majority of these piping segments are located in close proximity to the RCS main loop piping thus requiring personnel entry into high radiation areas within the containment. The dose associated with this testing was 1.5 man-Rem.

Conditions at Surry would yi~ld comparable exposure results, if the testing were performed.

IV. ALTERNATE PROVISIONS As an alternative to the Code required hydrostatic test of the subject Class 1 reactor coolant system pressure boundary connections, the following is proposed:

1. The RCS vent, drain, instrumentation, and sample connections will be visually examined for leakage, and any evidence of past leakage, with the isolation valves in the normally closed position each refueling outage during the ASME XI Class 1 System Leakage Test (IWB-5221).

2. The RCS vent, drain, instrumentation, and sample connections will also be visually examined with the isolation valves in the normally closed position during the 10-year ISi pressure test (IWB-5222 and Code Case N-498-1). This examination will be performed with the RCS at nominal operating pressure and at near operating temperature after satisfying the required 4-hour hold time.

In addition the RCS will be monitored for leakage at the following frequency pursuant to TS requirements:

1. The reactor coolant system leak rate will be monitored daily to assure the limit of one gallon per minute unidentified leakage is maintained.

Additionally, TS 3.1.C.1 states the following:

"Detected or suspected leakage from the Reactor Coolant System shall be investigated and evaluated. At least two means shall be available to detect reactor coolant system leakage. One of these means must depend on the detection of radionuclides in the containment."

The proposed alternative stated above will ensure that the overall level of plant quality and safety will not be compromised.

V. IMPLEMENTATION SCHEDULE This alternative to Code requirements will be followed upon receiving NRC approval for the remainder of the third ten-year inspection interval.

By a letter dated September 3, 1998 the NRC approved a similar relief request for Edwin I. Hatch Plant, Units 1 and 2.

ATTACHMENT 3 ASME SECTION XI RELIEF REQUEST NO. 7 SURRY POWER STATION UNIT 2

,------~----

Surry Power Station Unit 2 Third Ten Year Interval Request for Relief Number 7 I. IDENTIFICATION OF COMPONENTS Approximately 20, small diameter (~ 1 inch), Class 1, reactor coolant system (RCS) pressure boundary vent and drain, sample, and instrumentation connections.

II. IMPRACTICABLE CODE REQUIREMENTS Section XI, 1989 Edition, Examination Category B-P, Items 815.51 and 815.71 require system hydrostatic testing and associated VT-2 visual examination of all Class 1 pressure retaining piping and valves.

Ill. ISi BASIS FOR RELIEF REQUEST These piping segments are equipped with valves, or valve and flange, that provide for double isolation of the reactor coolant system (RCS) pressure boundary. These components are generally maintained closed during normal operation, and the piping outboard of the first isolation valve is, therefore, not normally pressurized. The proposed alternative provides an acceptable level of safety and quality based on the following:

1. ASME Section XI Code, paragraph IWA-4700, provides the requirements for hydrostatic pressure testing of piping and components after repairs by welding to the pressure boundary. IWA-4700(b)(5) excludes component connections, piping, and associated valves that are 1 inch nominal pipe size and smaller from the hydrostatic test. Consequently, hydrostatic testing and the associated visual examination of these _:5. 1 inch diameter RCS venUdrain/sampling connections once each 10-year interval is unwarranted considering that a repair weld on the same connections is exempted by the ASME XI Code.

2. The non-isolable portion of the RCS vent and drain connections will be pressurized and visually examined as required. Only the isolable portion of these small diameter vent and drain connections will not be pressurized.

3. All piping connections are typically socket-welded and the welds received a surface examination after installation. The piping and valves are nominally heavy wall (schedule 160 pipe and 1500# valve bodies). This piping and valve/flanges are towards the free end of a cantilever configuration (stub end isolated by either a valve or a flange). There is no brace or support for this portion of the pipe.

Consequently, this portion does not experience any thermal loading. This portion of the line is isolated during normal operation and does not experience pressure

e loading unless there is a leak at the first isolation valve. The valves do not have an extended operator, so the rotational accelerations at the valve do not produce significant stress. Since the lines are designed to the Code, the stresses towards the free end of the cantilever due to every other type of loading are only a small fraction of the applicable Code allowable. As a result, this portion of the lines is not subjected to high stress or high intensity cyclic loading.

The Technical Specifications (TS) require RCS leakage monitoring (TS Table 4.1-2A Item No. 10) during normal operation. Should any of the TS limits be exceeded, then appropriate corrective actions, which may include shutting the plant down, are required to identify the source of the leakage and restore the RCS boundary integrity.

The required pressure testing was recently performed during the 1998 North Anna Unit 1 refueling outage. Similar piping segments were pressurized by removing a flange and connecting a test rig. A majority of these piping segments are located in close proximity to the RCS main loop piping thus requiring personnel entry into high radiation areas within the containment. The dose associated with this testing was 1.5 man-Rem. Conditions at Surry would yield comparable exposure results, if the testing were performed.

IV. ALTERNATE PROVISIONS As an alternative to the Code required hydrostatic test of the subject Class 1 reactor coolant system pressure boundary connections the following is proposed:

1. The RCS vent, drain, instrumentation, and sample connections will be visually examined for leakage, and any evidence of past leakage, with the isolation valves in the normally closed position each refueling outage during the ASME XI Class 1 System Leakage Test (IWB-5221).

2. The RCS vent, drain, instrumentation, and sample connections will also be visually examined with the isolation valves in the normally closed position during the 10-year ISi pressure test (IWB-5222 and Code Case N--498-1). This examination will be performed with the RCS at nominal operating pressure and at near operating temperature after satisfying the required 4-hour hold time.

In addition the RCS will be monitored for leakage at the following frequency pursuant to TS requirements:

1. The reactor coolant system leak rate will be monitored daily to assure the limit of one gallon per minute unidentified leakage is maintained.

Additionally, TS 3.1.C.1 states the following:

e e "Detected or suspected leakage from the Reactor Coolant System shall be

" investigated and evaluated. At least two means shall be available to detect reactor coolant system leakage. One of these means must depend on the detection of radionuclides in the containment."

The proposed alternative stated above will ensure that the overall level of plant quality and safety will not be compromised.

V. IMPLEMENTATION SCHEDULE This alternative to Code requirements will be followed upon receiving NRG approval for the remainder of the third ten-year inspection interval.

By a letter dated September 3, 1998 the NRG approved a similar relief request for Edwin I. Hatch Plant, Units 1

ML18152B437

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