ML20084H361
| ML20084H361 | |
| Person / Time | |
|---|---|
| Site: | Grand Gulf  |
| Issue date: | 05/22/1995 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20084H349 | List: |
| References | |
| NUDOCS 9506050303 | |
| Download: ML20084H361 (6) | |
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UNITED STATES j-NUCLEAR REGULATORY COMMISSION If WASHINGTON, D.C. 2066H001 k.... j/
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO.122 TO FACILITY OPERATING LICENSE NO. NPF-29 ENTERGY OPERATIONS. INC.. ET AL.
GRAND GULF NUCLEAR STATION. UNIT 1 DOCKET NO. 50-416
1.0 INTRODUCTION
By letter dated June 25, 1993, as supplemented by letter dated April 13, 1995, the licensee (Entergy Operations, Inc.), submitted a request for changes to the Grand Gulf Nuclear Station, Unit 1 (GGNS) Technical Specifications (TSs).
The requested amendment deletes portions of the current TSs surveillance requirements (SRs) for the inboard Main Steamline Isolation Valve Leakage Control System (MSIV-LCS) heaters and blowers.
The deleted MSIV-LCS SRs will be relocated to documents that are included by reference in the Updated Final Safety Analysis Report (UFSAR) and are controlled by the licensee under the provisions of 10 CFR 50.59. The change is consistent with the format and content of the Improved Standard Technical Specifications (NUREG-1434, Revision 0).
The April 13, 1995, letter reduced the scope of the requested change to apply only to the inboard MSIV-LCS and provided additional clarifying information that did not change the initial proposed no significant hazards consideration determination.
Specifically, the licensee requests the deletion of the following specifications from the TSs and their relocation to the Grand Gulf UFSAR and other documents controlled under the provisions of 10 CFR 50.59:
1.
Relocate SR 3.6.1.9.1 to the UFSAR under the licensee's administrative control for the inboard MSIV-LCS; l
2.
Relocate SR 3.6.1.9.2 to the UFSAR under the licensee's administrative control.
The licensee has also modified the TSs Bases to reflect the above deletions.
9506050303 950522 PDR ADOCK 05000416 P
2.0 BACKGROUND
Section 182a of the Atomic Energy Act (the "Act") requires applicants for nuclear power plant operating licenses to include TSs as part of the license.
The Commission's regulatory requirements related to the content of TSs are set forth in 10 CFR 50.36.
That regulation requires that the TSs include items in five specific categories, including (1) safety limits, limiting safety system settings and limiting control settings; (2) limiting conditions for operation; (3) surveillance requirements; (4) design features; and (5) administrative controls. However, the regulation does not specify the particular requirements to be included in a plant's TSs.
The Commission has provided guidance for the contents of TSs in its " Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors" (" Final Policy Statement"), 58 FR 39132 (July 22,1993), in which the Commission indicated that compliance with the Final Policy Statement satisfies Section 182a of the Act.
In particular, the Commission indicated that certain items could be relocated from the TSs to licensee-controlled documents, consistent with the standard enunciated in Portland General Electric Co. (Trojan Nuclear Plant), ALAB-531, 9 NRC 263, 273 (1979).
In that case, the Atomic Safety and Licensing Appeal Board indicated that " technical specifications are to be reserved for those matters as to which the imposition of rigid conditions or limitations upon reactor operation is deemed necessary to obviate the possibility of an abnormal situation or event giving rise to an immediate threat to the public health and safety."
Consistent with this approach, the Final Policy Statement identified four criteria to be used in determining whether a particular matter is required to be included in the TSs, as follows:
(1)
Installed instrumentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary; (2) a process variable, design feature, or operating restriction that is an initial condition of a Design Basis Accident or Transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barrier; (3) a structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a Design Basis Accident or Transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier;
. (4) a structure, system, or component which operating experience or probabilisticsafe}yassessmenthasshowntobesignificanttopublic health and safety.
As a result, existing TSs requirements which fall within or satisfy any of the criteria in the Final Policy Statement must be retained in the TSs, while those TS requirements which do not fall wf thin or satisfy these criteria may be relocated to other, licensee-controlled documents.
3.0 EVALUATION By letter dated June 25, 1993, the licensee (Entergy Operations Inc.) for Grand Gulf, proposed changes to the plant TSs which relocate SRs for the HSIV-LCS (or simply LCS) to a licensee controlled document.
Specifically, the licensee proposed to revise the then current TS 3/4.6.1.4 " Main Steam Isolation Valve (MSIV) Leakage Control System (LCS)" to eliminate (relocate to other documents) all SRs for the MSIV-LCS except for the 18-month system functional performance test. The details of the 18-month performance test would also be deleted from the TSs, but would continue to be maintained in other licensee controlled documents. The proposed change was based in part on a conceptual redesign of the MSIV-LCS which eliminated the need for most of the active components in the LCS.
The incentive for this proposed plant specific TSs change is that safety-related parts of the system such as blowers, heaters, and flow elements have become increasingly difficult to find and the lead time excessively long. Therefore, it is a cost beneficial licensing action (CBLA).
Since that submittal, the staff reviewed the licensee's October 15, 1993, application to change the entire plant technical specifications to the new
" Improved" Standard Technical Specifications (ISTS) based on NUREG-1434,
" Standard Technical Specifications - General Electric Plants, BWR/6." The staff's safety evaluation approving that application was included in the February 21, 1995 issuance of Amendment No.120 to the Grand Gulf license. As a result of that amendment, the current specification for the LCS is TS 3.6.1.9, " Main Steam Isolation Valve (MSIV) Leakage Control System (LCS),"
which includes three SRs for the LCS. These three SRs require a 31-day test i
The Commission recently promulgated a propased change to 6 50.36, pursuant to which the rule would be amended to codify and incorporate these criteria. (See Proposed Rule, " Technical Specifications," 59 FR 48180 (September 20,1994)). The final policy statement specified that only limiting conditions for Reactor Core Isolation Cooling, Isolation Condenser, Residual Heat Removal, Standby Liquid Control, and Recirculation Pump Trip are to be included in the TS under Criterion 4.
In the proposed change to i 50.36, the Commission specifically requested public comments regarding application of Criterion 4.
Until additional guidance has been developed, Criterion 4 will not be applied to add TS restrictions other than those indicated above.
. of all blowers, a 31-day test of the inboard LCS heater element, and an 18-month functional test of both the inboard and outboard LCS subsystems.
All other SRs for the LCS, including the details of the 18-month functional test, were relocated to the Grand Gulf Technical Requirements Manual (TRM).
The existing MSIV-LCS actually consists of two subsystems, the inboard LCS and the outboard LCS.
The inboard LCS draws a negative pressure between the inboard and outboard MSIVs, and the outboard LCS develops a negative pressure between the outboard MSIV and a downstream main steam shutoff valve (MSSV).
The negative pressures, developed by the blowers in each subsystem assure that MSIV leakage will be directed to the auxiliary building where the leakage will be treated by the standby gas treatment system (SGTS).
The gist of the conceptual design as depicted in the June 1993, submittal was that the leakage could be directed to the auxiliary building without the use of the blowers.
If this flowpath could be assured without the blowers, the accident analysis dose calculations would remain unchanged since the MSIV leakage (the TSs allowed leakage rate has not changed) would still be treated by the SGTS.
The licensee's conceptual design has progressed to the point where the technical justification for eliminating the major active components (blowcrs, heaters, and flow element) from the design of the inboard LCS has been completed. Technical justification for similar modifications to the outboard LC5 have not yet been finalized. Therefore, because the outboard LCS does not include heaters or flow elements, and because the technical justification to eliminate the blowers from the outboard system may not be realized in the near future, the licensee has updated the proposed TSs change.
By letter dated April 13, 1995, the licensee supplemented the proposed TSs change revising existing TS 3.6.1.9 to delete the 31-day surveillance test for the inboard system blowers and heaters. The 31-day surveillance requirement to demonstrate operability of the outboard system blowers in addition to the requirement for an 18-month functional test of both the inboard and outboard systems will continue to be retained in the TSs.
The staff considers this a plant-specific TSs change and is, therefore, not a line-item improvement to the ISTS.
The licensee has performed analyses that show that for the inboard LCS, a flow rate of 50 standard cubic feet per hour (scfh) (25 scfh leak rate for the inboard MSIV and 25 scfh for the outboard MSIV) into the space between the MSIVs and a vacuum of -0.25 inches water in the auxiliary building, results in a sub-atmospheric pressure in the main steam lines demonstrating that the inboard LCS will maintain a sub-atmospheric condition without the use of blowers.
The -0.25 inch water pressure is the SGTS drawdown design pressure for the auxiliary building.
In addition, the licensee has performed testing which depressurized the main steam piping using a modified inboard LCS demonstrating the SGTS's ability to direct MSIV leakage to the auxiliary building without the inboard system blowers.
The staff has reviewed the results of the licensee's analyses and tests and concludes that the licensee has adequately demonstrated that the inboard LCS, after some minor modifications (setpoint changes and sloped piping for drainage), will be capable of performing its safety function without the use of blowers and their associated heaters and flow elements.
The staff, therefore, concludes that
. associated heaters and flow elements. The staff, therefore, concludes that the existing 31-day surveillance requirements of TS 3.6.1.9 for the inboard LCS blowers and heaters may be deleted. The affected SRs will be relocated to a licensee controlled document until such time as the design change is implemented disabling the affected components. The SRs will, therefore, continue to be performed until they are no longer applicable.
4.0 CONCLUSION
As a result of its review and evaluation, the staff concludes that the proposed changes to the SRs of TS 3.6.1.9 are acceptable, and should be approved.
This conclusion is based on the licensee's demonstration that the inboard LCS, after modifications, will be capable of performing its safety function without the use of the existing blowers, heaters, and flow elements, plus the fact that the surveillances will continue to be performed until the modifications are complete, disabling the affected components.
The SRs that the licensee proposes to delete from the TSs and relocate to the UFSAR are details of the licensee's surveillance methodology that are already contained in the plant procedures. The licensee adheres to verbatim compliance with all plant procedures and changes to those procedures may only be made by following the requirements of 10 CFR 50.59.
The staff concluded that the relocation of the above surveillance methodology details from the TSs to the UFSAR under licensee control will not reduce the assurance that the J
MSIV-LCS will remain operable as required and is acceptable to the staff.
The above relocated SRs relating to the MSIV-LCS are not required to be in the TSs under 10 CFR 50.36, and are not required to obviate the possibility of an abnormal situation or event giving rise to an immediate threat to the public health and safety.
Further, they do not fall within any of the four criteria set forth in the Commission's Final Policy Statement, discussed in the Introduction above.
In addition, the staff finds that sufficient regulatory controls exist under 10 CFR 50.59 to assure continued protection of the public health and safety. Accordingly, the staff has concluded that these requirements may be relocated from the TSs to the licensee's TSs Bases, UFSAR, or to the TRM incorporated by reference in the UFSAR Chapter 16, as applicable.
5.0. STATE CONSULTATION In accordance with the Commission's regulations, the Mississippi State official was notified of the proposed issuance of the amendment.
The State official had no comments.
6.0 ENVIRONMENTAL CONSIDERATION
The amendment changes a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20 and changes surveillance requirements.
The NRC staff has determined that the amendment involves no significant increase in the amounts, and no
. y significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendment involves no significant hazards consideration, and there has been no public comment on such finding (58 FR 39050). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9).
Pursuant to 10 CFR Sl.22(b), no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendment.
7.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that:
(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendment will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributor:
William T. Lefave Date: May 22, 1995