ML18005A608
| ML18005A608 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 09/29/1988 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML18005A607 | List: |
| References | |
| NUDOCS 8810030006 | |
| Download: ML18005A608 (5) | |
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UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D. C. 20555 8810030006 880929 PDR ADOCH,. 05000400 P
PNU SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO THE INSERVICE TESTING PROGRAM CAROLIIIA POWER 5 LIGHT COMPANY SHEARON HARRIS NUCLEAR POWER PLANT UNIT 1 DOCKET NO. 50-400
1.0 INTRODUCTION
The Code of Federal Regulations, 10 CFR 50.55a(g),
requires that inservice testing (IST) of ASPIE Code Class I, 2, and 3 pumps and valves be performed in accordance with Section XI of the ASME Boiler and Pressure Vessel Code and applicable
- addenda, except where specific written relief has been requested by the licensee and granted by the Commission.
The Regulations, 10 CFR 50.55a(a)(3)(i), (a)(3)(ii), and (g)(6)(i), authorize the Commis-sion to grant relief from these requirements.
In requesting relief, the licensee must demonstrate that (I) proposed alternatives provide an acceptable level of quality and safety, (2) compliance would result in hardship or unusual difficulties without a compensating increase in the level of quality and safety, or (3) conformance with certain requirements of the applicable Code edition and addenda is impractical for its fac i 1 ity.
The NRC.staff issued its Safety Evaluation of the Shearon Harris Nuclear Power Plant (SHNPP), Inservice Testing Program on April 27, 1988.
Subse-quently, in a letter to the staff, dated June 6, 1988, Carolina Power 8
Light Company (the licensee) disagreed with a staff position that future program changes should be reviewed by the staff prior to implementation.
The letter also proposed to include revised relief requests in the SHNPP IST Program.
- 2. 0 EVALUATION The staff, with assistance from its contractor
- EGSG, Idaho, evaluated the licensee's June 6, 1988 submittal.
This review was performed using the acceptance criteria of the Standard Review Plan, NUREG-0800, Section 3.9.6, and the Draft Regulatory Guide and Value/Impact Statement titled, "Identification of Valves for Inclusion in I'nservice Testing Program."
2.1 Relief Re uest RV-2:
The licensee requested relief from the reverse ow c osure requirement of Section XI, Paragraph IWV-3522 for check valve 1AF-117 in the turbine driven auxiliary feedwater supply to the steam generators.
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Licensee's Basis for Re uestin Relief:
The licensee stated:
The system has no design provision for verifica-tion of reverse flow closure.
The only possible test method involves pressurizing the downstream section of pipe and monitoring an upstream tap for evidence of gross leakage.
This method involves filling and draining large segments of the system.
Because of the time involved, ALARA consideration, and large amounts of wastes, it is not practical to perform testing except at refueling.
As an alternative, the licensee proposed to disassemble and visually inspect the valve during refueling outages.
Evaluation:
Section XI, IWV-3522, requires that check valves be exerc~sees to the position(s) required to fulfi11 their safety function and IWV-3521 requires that this testing be performed at least once every three months.
Verification of reverse flow closure for valve 1AF-117 can only be accomplished by leak testing or disassembly and inspection.
The staff position is that valve disassembly and inspection is an acceptable alternate method to verify valve closure and the appropriate frequency for this testing is during reactor refueling outages.
However, this testing method can be used only when it has been demonstrated that testing at the Code allowed frequencies (quarterly or during cold shutdowns) is impractical.
Valve reverse flow closure can be determined by pressurizirig the downstream section of pipe and monitoring an upstream pressure gauge or tap for evidence of gross leakage.
The licensee stated that this method involved filling and draining large segments of the system which is not practical because of the time involved, ALARA considerations and the large amounts of waste that would be generated.
It is not clear to the staff why a great deal of filling and venting would be necessary or why large amounts of waste would be generated to perform this testing.
PAID CPL-2165 S-0544 shows isolation valves and test taps both upstream and downstream of these check valves plus pressure instruments on the upstream piping, which could be used for valve testing during cold shutdowns.
ALARA can only be used for a relief request justification if the licensee provides the specific information for the affected component testing (i.e., radiation fields and time required in radiation area for testing).
The licensee's basis for relief does not provide an adequate technical justification for not performing the Code required testing during cold shutdowns, therefore, relief can not be
granted from the Code requirement to verify closure of this valve.
Based on the impracticality of leak testing or dis-assembling this valve quarterly during power operations, the reverse flow closure verification may be performed during cold shutdowns as permitted in Section XI, IWV-3522. If the valve closure has been demonstrated by valve disassembly, the pressure leak testing need not be performed during the same shutdown.
2.2 Relief Re uest RV-3:
The licensee has requested relief from the reverse ow c osure requirement of Section XI, Paragraph IWV-3522 for check valves lAF-201, 1AF-202, lAF-203, 1AF-204, 1AF-205, and lAF-206 in the auxiliary feedwater pump discharge line.
2.2.1 Licensee's Basis for Re uestin Relief:
The licensee stated:
The system has no design provision for verifica-tion of reverse flow closure.
The only possible test method involves pressurizing the downstream section of pipe and monitoring [anj upstream tap for evidence of gross leakage.
This method involves filling and draining large segments of the system.
Because of the time involved, ALARA consideration, and large amounts of wastes, it is not practical to perform testing except at refueling.
The only other alternative testing is to disassemble and visually inspect each valve.
During >>ormal plant operation, the Valves 1AF-201, 202, 203, 204, 205, and 206 will be verified to be in the closed position through the continual monitoring of installed temperature elements.
Unacceptable conditions require action in accordance with Plant Operating Procedures.
In
- addition, one valve off the f<otor-Driven Train and one valve off Turbine-Driven Train will be disassembled and Inspected at each refueling, and alternate valves wi 11 be done during subsequent refuelings.
Failure to pass inspection will initiate disassembly and inspection of the other valves on the same train.
2.2.2 Evaluation
Section XI, IWV-3522, requires that check valves be exercise to the positions(s) required to fulfilltheir safety function and IWY-3521 requires that this testing be performed at least once every three months. Yerification of reverse flow closure for these valves can only be accomplished by leak testing or disassembly.
The system design makes it impractical to perform the leak rate tests during power operations because there are no pressure taps downstream of the valves and using feedwater header pressure for leak testing could subject the test personnel to the safety hazards of venting high temperature, high pressure water.
Leak testing these valves during cold shutdowns is not practical because there are no test connections between these valves and the downstream isolation valves, therefore, to pressurize the downstream side of these check valves to verify their reverse flow closure would require filling and pressurizing the steam generators, portions of the main steam headers and portions of the main feedwater headers.
It would be impractical to perform this testing during cold shutdowns because it involves major system configuration changes which could unreasonably delay returning the plant to power.
The staff position is that valve disassembly and inspection is an acceptable alternate method to verify valve closure and the appropriate frequency for this testing is during reactor refueling outages.
The licensee proposed to monitor the upstream piping temperature on a continuous basis and to disassemble and inspect one valve in the motor driven auxiliary feedwater trains and one valve in the turbine driven auxiliary feedwater trains during each refueling outage on a sampling basis.
2.3 A different valve of each group is required to be disassembled, inspected and manually full-stroked at each refueling, until the entire group has been tested.
If it is found that the dis-assembled valve's full-stroke capability is in question, the remainder of the valves in that group must also be disassembled, inspected and manually full-stroked at the same outage.
Based on the impracticality of complying with the Code require-ments considering the burden on the licensee, such as delaying plant restart, if the Code requirements were imposed and the licensee's proposed alternate testing, the requested relief is granted pursuant to 10 CFR 50.55a(g)(6)(i) for valves 1AF-201, 1AF-202, 1AF-203, lAF-204, lAF-205, and lAF-206.
The licensee disagreed with a staff position relative to the implementation of future IST program changes.
In the June 6, 1988 letter, the licensee stated:
CPSL has reviewed the SE and agrees with the evaluations and conclusions contained in the Technical Evaluation Report (TER) with one exception.
Appendix C, Item I, last sentence suggests that the licensee make modifications to the program and submit them to the NRC for review.
We agree with program modifications where compliance to requirements is impractical, but disagree that they need to be submitted to the NRC unless they involve denied relief.
With regard to this issue, the NRC staff maintains the position stated in its April 27, 1988 letter to you.
The staff position with regard to this issue is that program changes that involve revisions, additional relief requests, or deletion of any components from the IST program should be submitted for staff review and should not be implemented prior to review and approval by the NRC.
3.0 CONCLUSION
Pursuant to 10 CFR 50.55a(g)(6)(i),
the requested relief from the require-ments of Section XI, Paragraph IWV-3522 is granted for check valves 1AF-201, lAF-202, 1AF-203, 1AF-204, 1AF-205, and 1AF-206 (Relief Request RV-3).
The staff has determined ttiat granting relief pursuant to 10 CFR 50.55a(g)(6)(i) is authorized by law and will not endanger life or property, or the common defense and security.
In making this determina-tion the staff has considered the alternate testing being implemented and the impracticality of performing the required testing considering the burden if the requirements were imposed.
The staff concludes that adequate justification has not been provided in Relief Request PV-2 for not performing Code required testing of valve 1AF-117 during cold shutdowns and, therefore, relief is not granted.
As stated in Section 2.3 of this safety evaluation, the staff's position regarding future IST program changes remains unchanged.
Principal Contributor:
K. Dempsey J. Schiffgens B. Buckley Dated:
September 29, 1988