ML040420106
| ML040420106 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  (NPF-003) |
| Issue date: | 02/26/2004 |
| From: | Anthony Mendiola NRC/NRR/DLPM/LPD3 |
| To: | Myers L FirstEnergy Nuclear Operating Co |
| Lyon C, NRR/DLPM, 415-1292 | |
| References | |
| TAC MC0367 | |
| Download: ML040420106 (9) | |
Text
February 26, 2004 Mr. Lew W. Myers Chief Operating Officer FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State Route 2 Oak Harbor, OH 43449-9760
SUBJECT:
DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 - RELIEF REQUEST RV-3 REGARDING INSERVICE TESTING FOR PRESSURIZER RELIEF VALVE (TAC NO. MC0367)
Dear Mr. Myers:
By letter dated August 11, 2003, FirstEnergy Nuclear Operating Company (the licensee) submitted a request for relief for Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse),
from certain requirements of the American Society of Mechanical Engineers Code for Operation and Maintenance of Nuclear Power Plants (OM Code), 1995 Edition with 1996 Addenda, for inservice testing (IST) of the pressurizer pilot-operated relief valve. Relief Request RV-3 described an impractical IST requirement with respect to relief valve RC2A and proposed alternative testing.
Based on the information provided in Relief Request RV-3, the Nuclear Regulatory Commission (NRC) staff concludes that relief may be granted from the inservice testing requirement on the basis that meeting the OM Code requirement is impractical. Therefore, pursuant to 10 CFR 50.55a(f)(6)(i), the NRC staff authorizes the IST program alternative proposed in Relief Request RV-3 for the third 10-year IST interval for Davis-Besse, which is scheduled to conclude on September 12, 2010. The licensees proposed alternative provides reasonable assurance of the valves operational readiness. Granting this relief is authorized by law and will not endanger 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.
L. Myers The detailed results of the staffs review are provided in the enclosed safety evaluation. If you have any questions concerning this action, please call Mr. F. Lyon of my staff at (301) 415-2296.
Sincerely,
/RA/
Anthony J. Mendiola, Chief, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Safety Evaluation cc w/encl: See next page
L. Myers The detailed results of the staffs review are provided in the enclosed safety evaluation. If you have any questions concerning this action, please call Mr. F. Lyon of my staff at (301) 415-2296.
Sincerely,
/RA/
Anthony J. Mendiola, Chief, Section 2 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-346
Enclosure:
Safety Evaluation cc w/encl: See next page DISTRIBUTION:
PUBLIC PD3-2 Reading WRuland AMendiola FLyon PCoates CGHammer DTerao DWeaver ACRS OGC GHill(4)
CLipa, RIII SReynolds, RIII Accession Number: ML040420106
- SE dated 2/6/04 OFFICE PM:PDIII-2 LA:PDIII-2 SC:EMEB OGC SC:PDIII-2 NAME FLyon PCoates DTerao*
RHoefling AMendiola DATE 02/12/04 02/11/04 02/06/04 02/19/04 02/26/04 OFFICIAL RECORD COPY
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE THIRD TEN-YEAR INTERVAL INSERVICE TESTING PROGRAM REQUEST FOR RELIEF RV-3 FIRSTENERGY NUCLEAR OPERATING COMPANY DAVIS-BESSE NUCLEAR POWER STATION, UNIT 1 DOCKET NO. 50-346
1.0 INTRODUCTION
By letter dated August 11, 2003, FirstEnergy Nuclear Operating Company (the licensee),
requested relief from certain requirements of the American Society of Mechanical Engineers (ASME) Code for Operation and Maintenance of Nuclear Power Plants (OM Code), 1995 Edition with 1996 Addenda, for the pressurizer pilot-operated relief valve (PORV) at Davis-Besse Nuclear Power Station, Unit 1 (Davis-Besse). The licensee requested relief for the duration of the third 10-year inservice testing (IST) interval, which began on February 1, 2002, and is scheduled to end on September 12, 2010.
2.0 REGULATORY EVALUATION
The Code of Federal Regulations, 10 CFR 50.55a, requires that IST of certain ASME Code Class 1, 2, and 3 pumps and valves be performed in accordance with the applicable edition of the ASME OM Code and applicable addenda, except where alternatives have been authorized or relief has been requested by the licensee and granted by the Commission pursuant to paragraphs (a)(3)(i), (a)(3)(ii), or (f)(6)(i) of 10 CFR 50.55a. 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 code requirements upon making the 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. Further guidance is given in GL 89-04, Supplement 1, and NUREG-1482, Guidelines for Inservice Testing at Nuclear Power Plants.
The licensees proposed Relief Request RV-3, requesting relief from certain requirements of the ASME OM Code, 1995 with 1996 Addenda, is similar to a relief request approved for Davis-Besse for the second 10-year IST interval by the NRC in a safety evaluation dated December 2, 1991.
The NRCs findings with respect to Relief Request RV-3 are given below.
3.0 TECHNICAL EVALUATION
3.1 ASME Code Component Affected The pressurizer PORV, RC2A, is an electrically controlled, pilot-operated, pressure-loaded relief valve with no external valve position indication. The PORV is an ASME Code Class 1, Category B valve located inside containment. The control room indication is based on the electrical demand signal to the solenoid-operated pilot valve. The other means of PORV relative position indication are downstream tailpipe temperature indication and acoustic monitors. The PORV is required to be capable of opening to provide a Reactor Coolant System vent path and to fail in the closed position.
3.2 Applicable Code Requirement The licensee is requesting relief from the following ASME OM Code requirements for inservice testing of valves (Subsection ISTC):
ISTC 4.2.4(a) - The limiting value(s) of full-stroke time of each power-operated valve shall be specified by the Owner.
ISTC 4.2.4(b) - The stroke time of all power-operated valves shall be measured to the nearest second.
ISTC 4.2.8 - Test results shall be compared to the initial reference values or reference values established in accordance with ISTC 3.4 and ISTC 3.5.
ISTC 4.2.8(b) - Other power-operated valves with reference stroke times of greater than 10 seconds shall exhibit no more than a +/-25% change in stroke time when compared to the reference value.
ISTC 4.2.8(d) - Other power-operated valves with reference stroke times of less than or equal to 10 sec shall exhibit no more than a +/-50% change in stroke time when compared to the reference value.
ISTC 4.2.9(a) - If a valve fails to exhibit the required change of obturator position or exceeds the limiting values of full-stroke time [see paragraph ISTC 4.2.4(a)], the valve shall be immediately declared inoperable.
ISTC 4.2.9(b) - Valves with measured stroke times that do not meet the acceptance criteria of paragraph ISTC 4.2.8 shall be immediately retested or declared inoperable. If the valve is retested and the second set of data also do not meet the acceptance criteria, the data shall be analyzed within 96 hr to verify that the new stroke time represents acceptable valve operation, or the valve shall be declared inoperable. If the second set of data meet the acceptance criteria, the cause of the initial deviation shall be analyzed and the results documented in the record of tests (see paragraph ISTC 6.3).
3.3 Licensees Basis for Relief The licensee requests relief from the above OM Code requirements on the basis that the required testing is impractical. The licensee states that the PORV is an electrically controlled, pilot-operated, pressure-loaded relief valve. Full stroking and stroke timing of the PORV cannot be visually verified since the valve mechanisms are internal to the valve. The licensee also states that the only available remote position indication for this valve does not indicate true valve position; therefore, full-stroke timing and the establishment of conventional stroke-time reference values cannot be performed. The licensee further states that compliance with the Code requirements would require changing the plant design to modify or replace the existing PORV to allow full-stroke timing.
3.4 Licensees Proposed Alternative Testing As an alternative to the above OM Code-required stroke and stroke-time requirements, the licensee proposes that the PORV be exercised at reduced pressure during plant shutdown on a cold shutdown frequency. PORV isolation block valve RC11 would be open during this test.
Full stroke exercising of the PORV would be demonstrated by opening the valve at a specified Reactor Coolant System (RCS) pressure and recording the amount of time to achieve a certain RCS pressure drop. The license states that the time required to achieve this pressure drop is dependent upon the obtained flow rate, which is related to valve position. The licensee states that the recorded time can be used for trending purposes to monitor PORV performance. The licensee proposes a reference value be established based upon a pressure change over a period of time and acceptance criteria based upon this reference value be defined and results trended to identify valve degradation. As further justification, the licensee states that testing would also be performed to further demonstrate the relative position of the PORV as indicated by acoustic monitors on the PORV discharge line and their associated computer point, as well as a computer point that monitors the tailpiece temperature of the PORV discharge piping.
Additionally, the licensee states that channel checks and calibrations are performed as required to fulfill Technical Specification Surveillance Requirements 4.3.3.6 (Post-Accident Monitoring Instrumentation) and 4.4.3 (Safety Valves and Pilot-Operated Relief Valves - Operating).
3.5 Evaluation The staff finds that testing of the PORV, RC2A, in order to meet the above OM Code requirements, would be impractical because the PORV is a pilot-operated pressure assisted relief valve with no external valve position indication. The control room indication is based on the electrical demand signal to the pilot valve, which is not a true indication of valve position.
The only other means of PORV position indication are downstream tailpipe temperature and acoustic monitors. However, these indications do not provide information about the amount of valve opening. With no positive means of valve indication, stroke timing by observation or physical measurement of the PORV disk position is not possible. Also, it is impractical to test this valve during power operation because it would cause an undesirable pressure transient in the reactor coolant system. Testing the PORV with the block valve closed gives little information about the PORV disk motion since the valve is pressure assisted in the open direction. It would be burdensome to require the licensee to replace this valve or make system modifications that permit valve testing to comply with the OM Code requirements.
The licensee has proposed to test the PORV at reduced system pressure during plant outages on a cold shutdown frequency by timing the pressure drop between specific pressures. The staff finds that the licensees proposed alternative test method is acceptable, since this method indirectly determines flow rate, full stroke exercising, and stroke timing. While not verifying the full stroke of the PORV, the acoustic monitors and tailpiece temperature monitors provide additional verification of PORV unseating and reclosure. Further, the staff finds that the licensees method for establishing acceptance criteria and corrective actions is acceptable, since the measured timing of the pressure drop will establish a reference value and acceptance criteria, and since the results will be trended to identify valve degradation.
4.0 CONCLUSION
The licensees proposed alternative to the requirements of paragraphs ISTC 4.2.2(a), ISTC 4.2.2(b), ISTC 4.2.8, ISTC 4.2.8(b), ISTC 4.2.8(d), ISTC 4.2.9(a), and ISTC 4.2.9(b) of the OM Code for the pressurizer pilot-operated relief valve, RC2A, is authorized pursuant to 10 CFR 50.55a(f)(6)(i) for the third 10-year IST interval, which is scheduled to conclude on September 12, 2010, based on the impracticality of performing the required testing and the burden on the licensee if the requirements were imposed. The licensees proposed alternative provides reasonable assurance of the valves operational readiness. Granting this relief is authorized by law and will not endanger 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.
Principal Contributor: G. Hammer Date: February 26, 2004
Davis-Besse Nuclear Power Station, Unit 1 cc:
Mary E. OReilly FirstEnergy Corporation 76 South Main St.
Akron, OH 44308 Manager - Regulatory Affairs FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State - Route 2 Oak Harbor, OH 43449-9760 Director, Ohio Department of Commerce Division of Industrial Compliance Bureau of Operations & Maintenance 6606 Tussing Road P.O. Box 4009 Reynoldsburg, OH 43068-9009 Regional Administrator U.S. Nuclear Regulatory Commission 801 Warrenville Road Lisle, IL 60523-4351 Michael A. Schoppman Framatome ANP 1911 N. Ft. Myer Drive Rosslyn, VA 22209 Resident Inspector U.S. Nuclear Regulatory Commission 5503 North State Route 2 Oak Harbor, OH 43449-9760 Barry Allen, Plant Manager FirstEnergy Nuclear Operating Company Davis-Besse Nuclear Power Station 5501 North State - Route 2 Oak Harbor, OH 43449-9760 Dennis Clum Radiological Assistance Section Supervisor Bureau of Radiation Protection Ohio Department of Health P.O. Box 118 Columbus, OH 43266-0118 Carol OClaire, Chief, Radiological Branch Ohio Emergency Management Agency 2855 West Dublin Granville Road Columbus, OH 43235-2206 Zack A. Clayton DERR Ohio Environmental Protection Agency P.O. Box 1049 Columbus, OH 43266-0149 State of Ohio Public Utilities Commission 180 East Broad Street Columbus, OH 43266-0573 Attorney General Office of Attorney General 30 East Broad Street Columbus, OH 43216 President, Board of County Commissioners of Ottawa County Port Clinton, OH 43252 President, Board of County Commissioners of Lucas County One Government Center, Suite 800 Toledo, OH 43604-6506 David Lochbaum, Nuclear Safety Engineer Union of Concerned Scientists 1707 H Street NW, Suite 600 Washington, DC 20006 The Honorable Dennis J. Kucinich United States House of Representatives Washington, D.C. 20515 The Honorable Dennis J. Kucinich, Member United States House of Representatives 14400 Detroit Avenue Lakewood, OH 44107 Mr. James P. Riccio Nuclear Policy Analyst Greenpeace 702 H. Street, NW, Suite 300 Washington, DC 20001 Paul Gunter Director Nuclear Watchdog Project Nuclear Information & Resource Service 1424 16th Street NW Suite 401 Washington, DC 20009