ML20127H506
| ML20127H506 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/12/1993 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20127H477 | List: |
| References | |
| NUDOCS 9301220348 | |
| Download: ML20127H506 (6) | |
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SAFETY EVALVATION BY THE OcFICE OF h0 CLEAR REACTOR REGULATION RELATED T0_AMENDMERI NO.13 TO FACIllTY OPERATING LICENSE NO. NPF-87 iga 5_ UTILITIES ELECTRIC COMPANY ET AL COMANCHE PEAX STEAM ELECTRIC STATION. UNIT 1 1
DOCKET NO. 50-445 1.0 BilBSDEl].@
By letter dated April 26, 1991, and supplemented by letters dated May 4,1992, and October 15, 1992, requested changes to the Technical Specifications (AppenTexas Utilities Electric Com the licensee)
Operating License No. NPF-87) for the Comanche Peak Steam Electric Station, Unit 1.
The proposed changes would be in accordance with the staff's safety _
evaluation (SE) and supplemental safety evaluation (SSE) described below to modify the engineered safety features actuation systems (ESFAS) and reactor trip system (RTS) instrumentation surveillance and testing.
2.0 JLAMEMD in response to growing concerns over the impact of current testing and maintenance requirements on plant operation, particularly as related to instrumentation systems, the Westinghouse Owners Group (WOG) initiated a program to develop a justification to be used to revise generic and plant-specific instrumentation technical specifict.tiont. Operating plants have experienced inadvertent reactor trips and safeguards actuations during performance of instrumentation surveillances, causing unnecessary transients and challenges of safety systems.
Significant time and effort on the part of operating staffs have been devoted to performing, reviewing, documenting, and tracking the various surveillance activities.
In response to this concern, the WOG submitted WCAP-10271, " Evaluation of Surveillance Frequencies and Out of Service Times for the Reactor Protection Instrunientation System,' to the NRC on February 3,1983. This resulted in the NRC publishing a SE in February 1985, that allowed for an increase-in the time allowed for an inoperable channel to be placed in the tripped _ condition from 1 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, and increased time for surveillance and maintenance testing in bypass for analog channels of the RTS. The SE also required quarterly testing to be conducted on a staggered basis.
9301220340 930112 PDR ADOCK 05000445 P
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. On March 20, 1986, the WOG submitted WCAP-10271, Supplement 2, " Evaluation of Survelliance frequencies and Out of Service Times for the Engineered Safety Systems Actuation Systems.'
In addition, on May 12, 1987, the WOG submitted WCAP-iO271, Supplement 2, Revision 1.
After reviewing these WCAPs, the NRC issued an SE on February 22, 1989 (letter from C.E. Rossi to R.A. Newton) and an SSE on Revision 1 on April 30, 1990 (letter from C.E. Rossi to G.T.
Goering).
These SEs approved quarterly surveillance test intervals (STis), an increase in the time allowed for an inoperable channel to be placed in the tripped condition from 1 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, increased time for surveillance and maintenance testing, and testing in bypass for analog channels of the ESFAS.
Staggered testing was not required for ESFAS analog channels and the requirement was removed from the R15 analog channels.
The SE also concluded that 4-hour test and 12-hour maintenance allowed outage times (A0Ts) are acceptable for ESFAS automatic actuation logic i.nd actuation relays.
The reduction in testing associated with these changes is expected to result in fewer inadvertent reactor trips and less frequent spurious actuations of ESFAS components.
As stated in the staff's SE and SSE described above, the increase of A0Ts and STis for the ESFAS analog channels and A0Ts for the actuation logic and relays will result in a slight increase in the probability of core damage accidents.
The staff concluded that an overall upper bound for the core damage frequency (C0F) increase due to the proposed ST]/A0T changes is less than 6 percent for Westinghouse PWR plants. The staff also concluded that actual CDF increases for individual plants are expected to be substantially less than 6 percent.
The staff considered this CDF increase to be small compared to the range of uncertainty in the CDF analyses and therefore acceptable.
Based on the WOG analyses and subsequent staff review, the staff concluded that the proposed STI and A0T changes for the ESFAS and RTS would have only a small, and therefore acceptable, impact on plant risk.
In WCAP-10271 Supplement 3, the Reactor Water Storage Tank (RWST) level channels were evaluated and found to be identical in configuration to the Steam Generator level channel and therefore the RWST level channels would be bounded by the unavailability analysis for the steam generator leval channel.
This amplified the analysis presented in the other supplements to encompass RWST level.
In both the february 22, 1989, SE and April 30, 1990, SSE, the NRC encouraged licensees to propose changes to their technical specifications that are consistent with the guidance provided by the staff.
An acceptable format for proposing technical specification changes based on the WCAPs was provided to the WOG ia the February 22, 1989 SE.
In order for the staff to find the licensee's submittals acceptable, the licensees were told that they must:
1.
Confirm the applicability of the generic analyses of WCAP-10271, Supplement 2 and WCAP-10271, Supplement 2, Revision 1, and
3-2.
Confirm that any increase in instrument drift due to the extended STis is properly accounted for in the setpoint calculation methodology.
(Licensees were advised to use the letter from C.E. Rossi to R.F.
Janecek, dated April 27, 1988, for guidance on this issue.)
CPSES incorporated most of the suggested STI and A0T relaxations in the original Technical Specifications issued in February,1990; however, in the months prior to license issuance and during Technical Specification development, all review and acceptance of the WCAPs and supplements was not completed. As a result, most, but not all provisions of WCAP-10271 and supplements were incorporated. This change proposes to incorporate the remainder of the changes.
3.0 EVALVATION As described above, in order to be considered for the generic technical specification changes, licensees ruust first make two specific findings, the first being that the licensee must confirm the applicability of the generic analyses of WCAP-10271, Supplement 2 and WCAP-10271 Supplement 2, Revision 1 to its facility, in the CPSES letter of April 26, 1991, the licensee stated that the methodology of WCAP-10271 and its supplements were applied to specific RTS and ESFAS function implemented via the Westinghouse Solid State Protection System (SSPS). A review was performed to assure that the functions used in the generic analysis and the employment of the SSPS to perform ESFAS function, as described in the generic analysis, are applicable to the CPSES design.
Based on their review, the licensee concluded that all changes-proposed in this amendment are addressed by the generic analysis except for RWST level.
RWST level was separately evaluated on a plant specific basis in WCAP-10271 Supplement 3.
This analysis concluded that RWST level is identical in configuration to the steam generator level channel; therefore, the system unavailabilities resulting from relaxed STIs and A0TS were essentially the same and will have no impact on' plant safety.
The second finding that needed to be addressed was the concern over-instrument drift over the extended STIs.
In their submittals, the licensee stated that it had implemented quarterly analog testing upon receipt of the operating license in February 1990, except for RWST level. The setpoint methodology contains adequate allowance to bound anticiaated drift over a three month period. Additionally, setpoint drift data las been trended since prior to-licensing to confirm this allowance. No excessive drift has been noted over this period.
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Specific changes proposed to be made to the CPSES technical specifications 1
include the following:
1.
Table 3.3-1, Functional Units 17 and 20 The licensee proposed to add new Action Statement 13 to Functional Unit 17 (Safety Injection Input from ESFAS) and Functional Unit 20 (Automatic Trip and Interlock Logic) to Table 3.3-1.
This change would increase the maintenance A0T of aa inoperable channel from 6 to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> and increase the allowed bypass time for surveillance testing from 2 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />.
The staff found this i W acceptable in the SE of April 30, 1990.
E.
M k 3.3-1, Note "e" The licensee proposed to delete note "e" of Tabla 3.3-1.
This change reflects the staff's finding that the A0T for instruments common to RPS and ESFAS do not have differing RPS and ESFAS requirements. Therefore, the change is acceptable.
3.
Table 3.3-1, Action Statement 12 The licensee proposed changing Action Statement 12 of Table 3.3-1 to increase the A0T for surveillance testing from 2 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This change, which was found acceptable in the staff's SE, is applicable to Functional Units 7 (Overtemperature N-16) and 8 (Overpower N-15).
4.
Table 3.3-2, Note "e" The licensee proposed to revise note "e" of Table 3.3-2 to make the time allowed to place the steam generator high level channel into tri) and the surveillance A0T consistent with the provisions for inoperable clannels in Action Statement 17. This is an editorial change which results from changing the action statement to 17 for the functional units to which note "e" applies, and is acceptable.
5.
Table 3.3-2, Functional Units 4.e and S.b The licensee proposes to increase the tima to place an inoperable channel in the tripped sosition from 1 to 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to sdd a provision that allows one additional ciannel.to be bypassed for up to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> for surveillance testing.
These changes give 3 channel systems the same provisions as 4 channel systems.
These changes, which were found acceptable in-the staff's SE, apply to Functional Units 4.e (Steam Line Pressure - Negative Rate High) and 5.b (Steam.
Generator Water Level -- High-High).
6.
Table 3.3-2, Functional Units 1.b, 2.b, 3.a.2, 3.b.2, 7.a, and ll.a The licensee proposes to delete Actions 33 and 26 to Table 3.3-2 that are no longer used and renumber ESF Action 12 to the'new Action 26.
This is an administrative change that avoids assigning the number 12 to two Action Statements.
5 7.
Table 3.3-2, Action Statements 17 and 23 The licensee proposed to revise Actions 17 and 23 to Table 3.3-2 to delete specific reference to STARTUP and/or POWER OPERATION and apply the broader term of ' operation *. This change avoids confusion with the Table 1.2 definitions of startup and power operation but does not change the applicable modes of these functions.
Therefore, this change is acceptable.
8.
Table 3.3-2, Action Statements 19, 22, ans 26 The licensee proposed to revise Actions 19, 22, and 26 of Table 3.3-2 to break the 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> shutdown time requirement into the more standard 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> to restore or be in at least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.
The proposed time limits, like the time limits in 3.0.3, will provide ample time for an orderly shutdown without excess stress on the plant.
Therefore, the staff finds these changes acceptable.
The licensee also proposes to change Action Statements 19, 22, and 26 to Table 3.3-2 to increase the A0T for surveillance testing from 2 to 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />. This change, which was found acceptable in the staff's SE, is appitcable to-Functional Units 1.b. 2.b, 3.a.2, 4.b, S.a. 6.a, 7.a. 7.b, and ll.a.
9.
Tabic 4.3-2, functional Unit 7.b The licensee has proposed to increase the STI from monthly to quarterly for functional Unit 7.b (RWST Level - Low-Low Coincident with Safety Injection).
WCAP-10271 Supplement 3 concluded that the PWST level channels are identical in configuration to the steam generator level channels which were approved for quarterly STI in the staff's SER.
Since the proposed change would result in essentially the same system unavailabilities and risks associated with relaxed SITS and A0Ts for the steam generator level channel, and will have no impact on plant safety, the staff finds this change acceptable.
10.
BASES 3/4.3.1 and 3/4.3.2 The licensee has proposed modifying Technical Specification Bases 3/4.3.1 and 3/4.3.2, RFACTOR TRIP SYSTEM AND ENGINEERED SAFE 1Y FEATURES ACTUATION SYSTEM INSTRUMENTATION, to incorporate reference WCAP-10271, Supplement 2 and the staff's SER. The staff finds these changes appropriate and acceptable.
Since the licensee's submittal has been based on the recommendations of the staff's SE and SSE, and the licensee has adequately addressed the required findings regarding the applicability of the analyses to the CPSES site, and the concerns about setpoint drift, the staff finds the above changes to the CPSES technical specifications acceptable.
4.0 STATE CONSULTAT10.tl In accordance with the Commission's regulations, the Texas State official was notified of the proposed issuance of the amendment.
The State official has no comments.
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, 5.0 LtiVIRONMENIA(J0N510 ERAT 10!i 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.
The NRC staff has determined that the amendment involves no significant ir, crease in the amounts, end no 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 Commissiot has previously issued a proposed finding that the amendment involves no significant hazards censideration and there has been no public comment on such finding (57 FR 32577 and 57 FR 55594). Accordingly, the amendment meets the eligibility criteria for categorical exclusion set forth in 10 CFR Section 51.22(c)(9).
Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issucnce of the amendment.
6.0 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 to 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: Donna Skay, PDIV-2/NRR Date:
January 12, 1993 I
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