ML023180004
| ML023180004 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 11/14/2002 |
| From: | Howe A NRC/NRR/DLPM/LPD2 |
| To: | Scalice J Tennessee Valley Authority |
| Hernan R W, NRR/NRC/DLPM,301-415-2010 | |
| References | |
| TAC MB6287, TAC MB6288, TAC MB6289 | |
| Download: ML023180004 (8) | |
Text
November 14, 2002 Mr. J. A. Scalice Chief Nuclear Officer and Executive Vice President Tennessee Valley Authority 6A Lookout Place 1101 Market Street Chattanooga, TN 37402-2801
SUBJECT:
SAFETY EVALUATION REGARDING TWO RELIEF REQUESTS FOR THE THIRD 10-YEAR INTERVAL INSERVICE TESTING PROGRAM AT BROWNS FERRY NUCLEAR PLANT, UNIT NOS. 1, 2 AND 3 (TAC NOS. MB6287, MB6288 AND MB6289)
By letter dated September 6, 2001, Tennessee Valley Authority requested relief from the American Society of Mechanical Engineers (ASME) Code requirements for the Standby Liquid Control (SLC) Pumps (i.e., PV-1) and the Control Rod Drive (CRD) Scram inlet and outlet valves (i.e., PV-2) for Browns Ferry Nuclear Plant, Unit Nos. 1, 2, and 3. The requested reliefs are for the Third 10-Year Inservice Testing (IST) Interval which began on September 1, 2002, and ends on August 31, 2012.
Relief Request PV-1 proposes to monitor SLC Pump vibration using a frequency response range of 6 Hz to at least 1000 Hz in lieu of testing from one-third minimum shaft rotational speed (2.89 Hz) to at least 1000 Hz. This range encompasses all frequencies from just below shaft rotational speed to the 1000 Hz minimum required by the ASME Code for Operation and Maintenance of Nuclear Power Plants. The licensees proposed alternative testing provides reasonable assurance of the operational readiness of the pumps in that testing in the range of 6 to 1000 Hz provides an adequate range to assess SLC pump degradation and its ability to perform its required function. Therefore, relief is authorized for Relief Request PV-1 pursuant to Title 10 of the Code Federal Regulations (10 CFR) Section 50.55a(a)(3)(i).
Relief Request PV-2 proposes to exercise all of the air operated Control Rod Scram inlet and outlet valves prior to THERMAL POWER exceeding 40 percent after each refueling outage and a representative sample (at least 10 percent) of the valves on a rotating basis at least once every 120 days cumulative operation in Mode 1 in lieu of exercising each valve nominally every 3 months. This request is consistent with Generic Letter 89-04, Supplement 1, Position 7, and the guidance provided in NUREG 1482. The licensees proposed alternative testing provides reasonable assurance of the valves operational readiness because testing will provide assurance that the CRD scram inlet and outlet valves are capable of performing their required functions. Therefore, relief is authorized for Relief Request PV-2 pursuant to 10 CFR 50.55a(a)(3)(i).
Granting relief pursuant to 10 CFR 50.55a(a)(3)(i) is authorized by law and will not endanger the life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Relief is authorized for Relief Requests PV-1 and PV-2 for the
J. A. Scalice duration of the third 10-year IST interval. The staffs evaluation and conclusions regarding relief requests PV-1 and PV-2 are contained in the enclosed Safety Evaluation.
If you have any comments regarding this matter, please contact the Project Manager, Kahtan N. Jabbour at 301-415-1496.
Sincerely,
/RA/
Allen G. Howe, Chief, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260 and 50-296
Enclosure:
As stated cc w/encl: See next page
J. A. Scalice November 14, 2002 duration of the third 10-year IST interval. The staffs evaluation and conclusions regarding relief requests PV-1 and PV-2 are contained in the enclosed Safety Evaluation.
If you have any comments regarding this matter, please contact the Project Manager, Kahtan N. Jabbour at 301-415-1496.
Sincerely,
/RA/
Allen G. Howe, Chief, Section 2 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-259, 50-260 and 50-296
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC BClayton DTerao PDII-2 R/F Srosenberg, EDO SUnikewicz HBerkow GHill (6) ACRS AHowe OGC KJabbour PFredrickson, RII ML023180004
- No Major Changes to SE OFFICE PDII-2/PM PDII-2/LA EMEB/DE* OGC PDII-2/SC NAME KJabbour BClayton DTerao AHowe DATE 11/04/02 11/01/02 10/18/02 11/07/02 11/12/02 OFFICIAL RECORD COPY
J. A. Scalice SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RELIEF REQUESTS PV-1 AND PV-2 TO THE THIRD 10-YEAR INTERVAL INSERVICE TESTING PROGRAM TENNESSEE VALLEY AUTHORITY BROWNS FERRY NUCLEAR PLANT, UNIT NOS. 1, 2, AND 3 DOCKET NOS. 50-269, 50-270, AND 50-296
1.0 INTRODUCTION
By letter dated September 8, 2002, Tennessee Valley Authority (the licensee) submitted its Third 10-Year Interval Inservice Testing (IST) Program for pumps and valves. The program included Relief Requests PV-1 and PV-2. The Browns Ferry Nuclear Plant (BFN) third 10-year IST interval began on September 1, 2002, and ends on August 31, 2012.
In Relief Request PV-1, the licensee has proposed to monitor standby liquid control (SLC) pump vibration using a frequency response range from 6 Hz to at least 1000 Hz in lieu of testing from 2.89 Hz to at least 1000 Hz. This range encompasses all frequencies from just below shaft rotational speed to the 1000 Hz minimum required by the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code).
In Relief Request PV-2, the licensee has proposed to exercise all of the air operated control rod scram inlet and outlet valves prior to THERMAL POWER exceeding 40 percent after each refueling outage and to exercise a representative sample (at least 10 percent) of the valves on a rotating basis at least once every 120 days (cumulative operation in Mode 1).
2.0 REGULATORY EVALUATION
Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a requires that IST of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with the ASME OM Code and applicable addenda, except where alternatives have been authorized or relief has been requested by the licensee and authorized by the Commission pursuant to paragraphs (a)(3)(i), (a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a. The Code of record for BFN Units 1, 2 and 3 is the 1995 Edition with 1996 Addenda to the ASME OM Code. In proposing alternatives or requesting relief, the licensee must demonstrate that: (1) the proposed alternatives provide an acceptable level of quality and safety; (2) compliance would result in hardship or unusual difficulty without a compensating increase in the level of quality and safety; or (3) conformance is impractical for its facility. Section 50.55a authorizes the Commission to approve alternatives and to grant relief from ASME Code requirements upon making the Enclosure
necessary findings. NRC guidance contained in Generic Letter (GL) 89-04, Guidance on Developing Acceptable Inservice Testing Programs, provides alternatives to the Code requirements which are acceptable to the staff. Further guidance is given in GL 89-04, Supplement 1, and NUREG-1482, Guidelines for Inservice Testing at Nuclear Power Plants.
By letter dated September 8, 2002, Tennessee Valley Authority (TVA or the licensee) submitted its third 10-year IST program for pumps and valves. The BFN third 10-year IST interval began on September 1, 2002, and ends on August 31, 2012. The program was developed in accordance with the requirements of the 1995 Edition with 1996 Addenda to the ASME OM Code.
The NRCs findings with respect to authorizing alternatives and granting or denying the IST program relief requests are given below.
3.0 TECHNICAL EVALUATION
The staff has reviewed the licensees regulatory and technical analysis in support of its requests for relief from ASME OM Code IST requirements which are described in Appendices B and C of the licensees submittal. The detailed evaluation below supports the conclusion that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by the operation in the proposed manner, (2) such activities will be conducted in compliance with the Commissions regulations, and (3) the issuance of the relief will not be inimical to the common defense and security or to the health and safety of the public.
3.1 Relief Request No. PV-1 In Relief Request PV-1 to the BFN third interval 10-year IST program, the licensee has proposed to monitor SLC pump vibration using a frequency response range from 6 Hz to at least 1000 Hz in lieu of testing from 2.89 Hz to at least 1000 Hz. This range encompasses all frequencies from just below shaft rotational speed to the 1000 Hz minimum required by the ASME OM Code.
The Code of record for BFN Units 1, 2 and 3 is the 1995 Edition with 1996 Addenda to the ASME OM Code. Subparagraph ISTB 4.7.1(f) of the ASME OM Code requires that the frequency response range of the vibration measuring transducers and their readout shall be from one-third minimum pump shaft rotational speed to at least 1000 Hz. For the case of the SLC pumps, this would entail testing and evaluation at 2.89 Hz to at least 1000 Hz. The intent of the low-frequency range of testing is to detect all noise contributors that could indicate degradation or wear of pump components. An example is oil swirl in sleeve type bearings. The SLC pumps are constructed with roller bearings. Roller bearing wear is detected at running frequencies well above the normal operating frequencies. Testing within the range of 6 to 1000 Hz can detect roller bearing wear. Therefore, there is no added value or additional technical information to be gained by testing at 2.89 Hz.
This proposed relief request is consistent with staff guidelines in NUREG-1482, Section 5.4.
Regarding PV-1, it should be noted that the SLC pumps are defined as Group B pumps per ISTB 1.3. Testing in accordance with the OM Code would not constitute a hardship or unusual difficulty as stated in PV-1 because low-frequency probes and equipment upgrade packages for very low frequency testing are commercially available and in common use. However, the staff
finds that Code-required testing would not provide valuable information as to the condition of the SLC pumps and testing is considered to be impractical within the limits of design. The staff further finds the licensees proposed alternative testing provides reasonable assurance of the operational readiness of the pumps in that testing in the range of 6 to 1000 Hz provides an adequate range to assess SLC pump degradation and its ability to perform its required functions.
On the basis of the above discussion, the staff concludes that the proposed alternative in PV-1 provides an acceptable level of quality and safety; therefore, Relief Request PV-1 is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
3.2 Relief Request No. PV-2 In Relief Request PV-2 to the BFN third interval 10-year IST program, the licensee has proposed to exercise all of the air-operated, control rod scram inlet and outlet valves prior to THERMAL POWER exceeding 40 percent after each refueling outage and to exercise a representative sample (at least 10 percent) of the valves on a rotating basis at least once every 120 days (cumulative operation in Mode 1).
The Code of record for BFN Units 1, 2 and 3 is the 1995 Edition with 1996 Addenda to the ASME OM Code. Paragraph ISTC 4.2.1 of the ASME OM Code requires that active Category A and B valves shall be nominally tested every 3 months.
BFN Technical Specifications (TS) Section 3.1.4 requires scram testing and rod insertion timing to be performed on all control rod drive (CRD) mechanisms prior to THERMAL POWER exceeding 40 percent after each refueling outage and a representative sample (at least 10 percent) to be tested on a rotating basis at least once every 120 days (cumulative operation in Mode 1) with reactor coolant pressure > 800 psig. The 120-day frequency is based on operating experience that shows that control rod scram times do not significantly change over the operating cycle. The representative sample remains representative only if no more than 20 percent of the control rods tests are determined to be slow. Previous approval was based on a representative test sample every 16 weeks (112 days). The current request is 120 days.
The proposed relief request is consistent with GL 89-04, Position 7, which states, . . . the rod scram test frequency in the facility TS may be used as the valve testing frequency to minimize rapid reactivity transients and wear of the control rod drive mechanisms. This position is re-affirmed by the staff in NUREG-1482. The change in test frequency is based on the changes to TS during the second 10-year IST interval and is, therefore, acceptable.
The staff finds that the licensees proposed alternative testing provides reasonable assurance of the valves operational readiness because testing will provide assurance that the CRD scram inlet and outlet valves are capable of performing their required functions.
On the basis of the above discussion, the staff concludes that the proposed alternative in PV-2 provides an acceptable level of quality and safety; therefore, Relief Request PV-2 is authorized pursuant to 10 CFR 50.55a(a)(3)(i).
4.0 CONCLUSION
The staff concludes that for Relief Requests PV-1 and PV-2, relief is authorized pursuant to 10 CFR 50.55a(a)(3)(i) on the basis that the proposed alternatives in PV-1 and PV-2 provide an acceptable level of quality and safety. Granting relief pursuant to 10 CFR 50.55a(a)(3)(i) is authorized by law and will not endanger the life or property or the common defense and security, and is otherwise in the public interest giving due consideration to the burden upon the licensee that could result if the requirements were imposed on the facility. Relief is authorized for both Relief Requests PV-1 and PV-2 for the duration of the third 10-year IST interval.
5.0 REFERENCES
- 1. U.S. Code of Federal Regulations, Domestic Licensing of Production and Utilization Facilities, Part 50, Chapter I, Title 10, Energy, paragraph 50.55a(a)(3)(i).
- 2. U.S. Code of Federal Regulations, Domestic Licensing of Production and Utilization Facilities, Part 50, Chapter I, Title 10, Energy, paragraph 50.55a(f)(6)(i).
- 3. American Society of Mechanical Engineers, ASME Code for Operation and Maintenance of Nuclear Power Plants, 1995 Edition with 1996 Addenda, New York, NY.
- 4. U.S. Nuclear Regulatory Commission, Guidance on Developing Acceptable Inservice Testing Programs, Generic Letter 89-04, through Supplement 1, April 4, 1995.
- 5. U.S. Nuclear Regulatory Commission, Guidelines for Inservice Testing at Nuclear Power Plants, NUREG-1482, April 1995.
- 6. U.S. Nuclear Regulatory Commission, Relief Request Reviews, NRR Office Instruction LIC-102, July 18, 2002.
- 7. Tennessee Valley Authority, Browns Ferry Nuclear Plant, Units 1, 2 and 3, Inservice Testing (IST) Program, Third Ten-Year Interval Program, Revision 0, Docket Nos.
50-259, 50-260 and 50-296.
- 8. Tennessee Valley Authority, Browns Ferry Nuclear Plant, Units 1, 2 and 3 Improved Technical Specifications, Section 3.1.4, Control Rod Scram Times, and Bases Section B 3.1.4.
Principal Contributor: S. Unikewicz, NRR Date: November 14, 2002
Mr. J. A. Scalice BROWNS FERRY NUCLEAR PLANT Tennessee Valley Authority cc:
Mr. Karl W. Singer, Senior Vice President Mr. Mark J. Burzynski, Manager Nuclear Operations Nuclear Licensing Tennessee Valley Authority Tennessee Valley Authority 6A Lookout Place 4X Blue Ridge 1101 Market Street 1101 Market Street Chattanooga, TN 37402-2801 Chattanooga, TN 37402-2801 Mr. James E. Maddox, Acting Vice President Mr. Timothy E. Abney, Manager Engineering & Technical Services Licensing and Industry Affairs Tennessee Valley Authority Browns Ferry Nuclear Plant 6A Lookout Place Tennessee Valley Authority 1101 Market Street P.O. Box 2000 Chattanooga, TN 37402-2801 Decatur, AL 35609 Mr. Ashok S. Bhatnagar, Site Vice President Senior Resident Inspector Browns Ferry Nuclear Plant U.S. Nuclear Regulatory Commission Tennessee Valley Authority Browns Ferry Nuclear Plant P.O. Box 2000 P.O. Box 149 Decatur, AL 35609 Athens, AL 35611 General Counsel State Health Officer Tennessee Valley Authority Alabama Dept. of Public Health ET 11A RSA Tower - Administration 400 West Summit Hill Drive Suite 1552 Knoxville, TN 37902 P.O. Box 303017 Montgomery, AL 36130-3017 Mr. Robert J. Adney, General Manager Nuclear Assurance Chairman Tennessee Valley Authority Limestone County Commission 6A Lookout Place 310 West Washington Street 1101 Market Street Athens, AL 35611 Chattanooga, TN 37402-2801 Mr. Robert G. Jones, Plant Manager Browns Ferry Nuclear Plant Tennessee Valley Authority P.O. Box 2000 Decatur, AL 35609