ML18039A852
| ML18039A852 | |
| Person / Time | |
|---|---|
| Site: | Browns Ferry  |
| Issue date: | 08/09/1999 |
| From: | NRC (Affiliation Not Assigned) |
| To: | |
| Shared Package | |
| ML18039A851 | List: |
| References | |
| NUDOCS 9908260177 | |
| Download: ML18039A852 (8) | |
Text
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NUCLEAR REGULATORY COMMISSION SAFETY EVALUATIONBY THE OFFICE OF NUCLEAR REACTOR REGULATION REQUEST FOR TEMPORARY EXEMPTION FROM THE REQUIREMENTS OF 10 CFR 50.65 THE MAINTENANCERULE BROWNS FERRY NUCLEAR PLANT - UNIT 1 TENNESSEE VALLEYAUTHORITY DOCKET NO 50-259
1.0 INTRODUCTION
By letter dated February 4,1999, Tennessee Valley Authority (TVA), the licensee for the Browns Ferry Nuclear Plant (BFN) - Units 1, 2 and 3, requested that the U.S. Nuclear Regulatory Commission (NRC) provide a temporary exemption, pursuant to the provisions of 10 CFR 50.12(a), from the requirements of 10 CFR 50.65, "Requirements for Monitoring the Effectiveness of Maintenance at Nuclear Power Plants" for BFN Unit 1
~ As stated in the letter, the requested exemption is to remain in effect until TVAdecides to return Unit 1 to operation, at which time full implementation and re-evaluation of the maintenance rule program will be required.
2.0 REGULATORY REQUIREMENTS Paragraph (a)(1) of the rule requires, in part, that "Each holder of an operating license under A)50.21(b) or 50.22 shall monitor the performance or condition of structures, systems, or components, against Licensee-established goals, in a manner sufficient to provide reasonable assurance that such structures, systems, or components, as defined in paragraph (b), are capable of fulfillingtheir intended functions. Such goals shall be established commensurate with safety and, where practical, take into account industry-wide operating experience.
When the performance or condition of a structure, system, or component does not meet established goals, appropriate corrective action shall be taken." Additionally, paragraph (b) of the rule, states that the scope of the monitoring program specified in paragraph (a)(1) of this section shall include safety related and non-safety related structures, systems, and components as follows:
"(1) Safety related structures, systems, and components that are relied upon to remain functional during and following design basis events to ensure the integrity of the reactor coolant pressure boundary, the capability to shut down the reactor and maintain it in a safe shutdown condition, and the capability to prevent or mitigate the consequences of accidents that could result in potential offsite exposure comparable to the guidelines in f50.34(a)(1) or $100.11 of this chapter, as applicable.
"(2) Non-safety related structures, systems, or components:
(i) that are relied upon to mitigate accidents or transients or are used in plant emergency operating procedures (EOPs); or O'P08260i77 990809 POR ADOCK 05000259 P
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(ii) Whose failure could prevent safety related structures, systems, or components from fulfilling their safety related function; or (iii)Whose failure could cause a reactor scram or actuation of a safety related system."
3.0 BACKGROUND
During the period of April4 - 18, 1997, the NRC conducted an inspection of the implementation of the maintenance rule, 10 CFR 50.65 at BFN. The results of that inspection were documented in NRC combined Inspection Reports 50-259/97-04, 50-260/97-04, and 50-297/97-04 (IR 97-
- 04) issued May 21, 1997. The results of IR 97-04 determined that, in general, TVA's actions to implement the rule for BFN Unit 1 were technically adequate to support the interface functions with BFN Units 2 and 3 and that the BFN Unit 1 systems required to maintain spent fuel pool cooling were properly scoped in the rule. However, an Unresolved Item (URI 50-259/97-04-01) was identified for BFN Unit 1 concerning the acceptability of TVA's approach to addressing the SSCs required to be within the scope of f50.65 (b).
As described in IR 97-04, TVA's approach for the limited scoping of BFN Unit 1 SSCs was based on (1) the long-term shutdown and defueled status of the plant, (2) procedural controls that would require re-evaluation of scoping considerations if BFN Unit 1 conditions were to change, and (3) the docketed commitment to notify the NRC of any plans to return the unit to operation, which would require Commission approval prior to restart.
However, the inspection team was concerned with TVA's methodology, which excluded the majority of the SSCs required to be within the scope of f50.65(b) for a facilitylicensed under $50.21(b) or $50.22 (i.e., the high pressure coolant injection, reactor core isolation cooling, main steam and reactor water recirculation systems were not included in the scope).
The inspection team also identified that performance monitoring, data collection, and trending activities were not being performed on these systems..
Subsequently, the NRC informed TVAby letter dated July 30, 1997, that absent the certification per $50.82(a)(1) for licensed facilities in a decommissioning status, all the requirements of
$50.65 applied to BFN Unit 1. Specifically, the NRC's letter stated that the existing scope of SSCs for BFN Unit 1 was inconsistent with the requirements of the rule. The NRC's letter also provided the following three alternatives to TVAin order to address the existing condition:
(1) Revise the scope of the maintenance rule monitoring program for BFN Unit 1 to include structures, systems and components as specified in paragraph (b) of the rule, or (2) Submit a written certification to the NRC as specified in 10 CFR 50.82 (a)(1) that TVA has decided to permanently cease BFN Unit 1 operations, or (3) Petition the NRC for an exemption from the requirements of the rule that are not currently being met.
The staff requested TVAto describe which of these three alternatives it considered to be applicable or propose another course of action that it believed satisfied the requirements of the rule. TVAresponded by letter dated September 29, 1997, asserting that TVAdid not consider the selection of any of the three alternatives warranted because TVA's program to implement the maintenance rule for BFN Unit 1 was in compliance with 10 CFR 50.65.
the provisions of 50.65(a)(2) to BFN Unit 1, because they could not demonstrate that the affected SSCs would remain capable of performing their intended functions.
Allof the newly scoped BFN Unit 1 SSCs would, therefore, be placed in an (a)(1) status under the rule. As stated by TVA, the performance or condition monitoring of many of the BFN Unit 1 SSCs would not satisfy the established program goals, and corrective action would oe required in accordance with $50.65(a)(1).
TVA reiterated that they have no established plans to restart BFN Unit 1, and no recovery activities are currently being conducted on the unit. Therefore, TVA's proposed approach would define the corrective actions as those necessary before the unit could restart, which would result in the newly scoped BFN Unit 1 SSCs remaining in an (a)(1) status for an indefinite period of time.
Based on the information contained in the April 3, 1998 letter, the staff concluded that the proposed approach did not satisfy the requirements of $50.65(a)(1) in that the rule requires, in part, that each holder of an operating license "shall monitor [emphasis added] the performance or condition of structures, systems, or components, against licensee-established goals, in a manner sufficient to provide reasonable assurance that such structures, systems, and components, as defined in paragraph (b), are capable of fulfillingtheir intended functions."
Contrary to this requirement, TVA's proposed approach for BFN Unit 1 does not demonstrate the effective monitoring of SSCs against established goals, in that no provisions for actively confirming the performance or condition of SSCs within the scope of the rule are defined nor does it establish goals that are commensurate with safety.
Furthermore, the consideration of industry-wide operating experience required by (a)(1) was not addressed in TVA's proposal.
Therefore, the staff has determined that TVAis not in compliance with f50.65 at BFN Unit 1.
4.0 EVALUATION As described in 10 CFR 50.12, the Commission may, upon application by any interested person or upon its own initiative, grant exemptions from the requirements of 10 CFR Part 50 when (1).the exemptions are authorized by law, will not present an undue risk to the public health and safety, and are consistent with the common defense and security, and (2) when special circumstances are present.
In accordance with the provisions of f50.12, the staff reviewed TVA's request for a temporary exemption from the requirements of 10 CFR 50.65(b), as described in their letter to the NRC dated February 4, 1999.
Specifically, the staff reviewed TVA's justification related to the special circumstances which would support the request for an exemption to the requirements of f50.65(b), described in Sections (ii), (iii), and (v) of 10 CFR 50.1 2 (a)(2) which state:
"(i)
Application of the regulation in the particular circumstance would not serve the underlying purpose of the rule.. ~.
"(ii)
Compliance would result in undue hardship or other costs that are significantly in excess of those contemplated when the regulation was adopted, or that are significantly in excess of those incurred by others similarly situated..
~ ~
"(v)
The exemption would provide only temporary relief from the applicable regulation and the licensee or applicant has made a good faith effort to comply with the regulation...."
As described in TVA's exemption request, "The underlying purpose of the maintenance rule is to ensure that SSCs of nuclear power plants be maintained so that the plant SSCs willperform
their intended function when required." The exemption request also states, "In its current long-term defueled and administrative hold status, most of the Unit 1 systems are not required to perform the functions required to be monitored by 10 CFR 50.65(b) and cannot perform these functions due to the lay-up status of the unit," and further states "TVAwillimplement the Maintenance Rule for Unit 1 systems not currently under the scope of the rule at restart."
The staff agrees with TVA's position that because of the defueled and long term lay-up status of BFN Unit 1, the safety functions of the affected SSCs willnot be required until the restart of BFN Unit 1. Therefore, the staff concurs with TVA's position that because of the particular circumstances that exist at BFN Unit 1, the application of the maintenance rule to the entire population of SSCs required to be within the scope of $50.65(b) for an operating facility, would not serve the underlying purpose of the rule.
Additionally, as stated in TVA's temporary exemption request, "Strict compliance with the 10 CFR 50.65(a)(1) requirement of the rule for timely corrective actions would result in unnecessary expenditure of considerable funds and resources to bring equipment into conformance with the goals related to the intended safety functions of BFN Unit 1 SSCs.
Review of the rule and the Statements of Consideration indicate that the application of the rule to a plant in an extended lay-up period was not contemplated."
The staff agrees with TVA's position that the application of the rule to a plant in an extended lay-up period was not contemplated during the development of the rule. Accordingly, the staff concurs with TVA's position, concerning the provisions of $50.12(a)(2)(iii), in that compliance with the requirements of $50.65(a)(1) for the implementation of timely corrective actions in order to bring equipment into conformance with the goals related to the intended safety functions of BFN Unit 1 SSCs would result in the expenditure of significant resources that were not contemplated when f50.65 was adopted.
TVA's exemption request also states that they have implemented a program that is designed to comply with the purpose and intent of the maintenance rule for BFN Unit 1. This program which was described in a ietter to the NRC dated September 29, 1997, utilizes a scoping methodology which is "slightly"different from the methodology endorsed by the staff in NRC Regulatory Guide 1.160, "Monitoring the Effectiveness of Maintenance at Nuclear Power Plants." TVA further'stated that, for BFN1 in its current defueled status, most of the BFN Unit 1 SSCs are not required to perform the functions that would be monitored under the maintenance rule and that these SSCs cannot perform these functions due to the lay-up status of the unit. The BFN Unit 1 systems that perform a required safety function in the defueled condition or that directly support BFN Unit 2 or Unit 3 operation are included in the maintenance rule program as appropriate. The lay-up status of BFN Unit 1 was appropriately recognized and factored into the
'scoping of BFN Unit 1 SSCs for the maintenance rule program.
As stated by TVA, the current maintenance rule program also explicitly requires that the scoping of BFN Unit 1 SSCs be re-evaluated if the status of Unit 1 changes.
The staff agrees that the maintenance rule program for BFN Unit 1, described in TVA's letter to the NRC dated September 29, 1997, represents an exception to the scoping methodology described in Regulatory Guide 1.160.
However, as determined by the staff, the attributes of TVA's current maintenance rule program for BFN Unit 1, appear to be adequate to address the limited scope of SSCs necessary to support the interface functions with BFN Units 2 and 3 and to monitor the performance or condition of all SSCs associated with the storage, control, and maintenance of spent fuel in a safe condition. Therefore, the staff concurs with TVA's current maintenance rule implementation program, which explicitly requires that the scoping of Unit 1 SSCs be re-evaluated if the status of Unit 1 changes.
5.0 CONCLUSION
As a result of the review of TVA's request for a temporary exemption from the requirements of 10 CFR 50.65, dated February 4. 1999, the staff has concluded that pursuant to the provisions of 10 CFR 50.12(a), the exemption should be granted.
Specifically, based on the established scope of TVA's maintenance rule program for BFN Unit 1 systems that support the interface functions with BFN Unit 2 and 3 and the determination that BFN Unit 1 SSCs required to maintain spent fuel pool cooling are properly monitored and maintained to assure safe plant operation, the staff has determined that the approval of the requested temporary exemption from the explicit scoping requirements of f50.65(b) will not present an undue risk to the public health and safety. TVA's request for temporary exemption also states that the current BFN maintenance rule program requires that if Unit 1 conditions change, the affected SSCs will be reevaluated for 10 CFR 50.65 applicability.
Principal Contributors:
Robert M. Latta Albert W. De Agazio August 9, 1999
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