ML20138F708
| ML20138F708 | |
| Person / Time | |
|---|---|
| Site: | Mcguire, McGuire  |
| Issue date: | 12/07/1985 |
| From: | Tucker H DUKE POWER CO. |
| To: | Harold Denton, Youngblood B, Youngbood B Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20138F716 | List: |
| References | |
| GL-85-09, GL-85-9, NUDOCS 8512160157 | |
| Download: ML20138F708 (7) | |
Text
e DUKE POWER GoMPm P.O. DOX 33189 CIIAHLOTTE, N.C. 28242 IIAL D. TUCKER TELEPHONE me reesioewv (704) 373-45:M tit:CLRam reoOUCTHM' -
DMember 7, 1%5 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555 Attention: B.J. Youngblood, Director PWR Project Directorate #4
Subject:
McGuire Nuclear Station Docket Numbers 50-369/370 Proposed Technical Specification Changes for Reactor Trip Breaker Testing (Generic Letter 85-09)
Dear Mr. Denton:
Attached are proposed license amendments for McGuire Nuclear Station Facility Operating Licenses NPF-9 (Unit 1) and NPF-17 (Unit 2).
The proposed changes will incorporate testing and surveillance requirements for Reactor Trip Breakers (RTBs) which generally conform to the intent of Generic Letter 85-09.
Attachment I contains the Technical Specification changes, Attachment II contains a Technical Justification and Safety Analysis, and Attachment III provides an analysis conforming to the standards contained in 10 CFR 50.92 as required by 10 CFR 50.91. This analysis concludes that the proposed amendments would not have an adverse safety impact.
It is requested that the provisions of these changes be made effective 30 days after issuance, to allow appropriate administrative changes to be made.
In addition it is requested that, upon approval of these Technical Specification changes, Paragraph 2.c.(12) of Facility Operating License NPF-17 be deleted.
That paragraph imposes license conditions which duplicate the intent of Generic Letter 85-09 relative to testing of RTBs. A discussion to support this removal is presented in Attachment IV.
This request involves one application for amendment to the McGuire's Operating License. Accordingly, pursuant to 10 CFR 170.21, a check for $150.00 is enclosed.
Please feel free to contact us if you require any additional information.
Very truly yours,
< .[I R Hal B. Tucker 8512160157 051207 SAG /jgm PDR ADOCK 05000369 PDR p
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Mr.-Harold'R. Denton, Director-December 7, 1985 L'! -Page 2 cc: Dr. J. Nelson Grace, Regional Administrator
-U.S. Nuclear Regulatory Commission Region II: . .
101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr."Dayne= Brown, Chief' Radiation Protection Branch Division of Human Resources P.O. Box 12200 Raleigh,' North Carolina 27605 Mr. W.T. Orders NRC Resident Inspector
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McGuire Nuclear Station
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Mr. Harold R. Denton.
-December 7, 1985 Page 3 HAL B. TUCKER, being' duly sworn, states that he is Vice President of Duke
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Power Company; that he is authorized on the part of said Company to sign and-file with the Nuclear Regulatory Commission this revision to the McGuire Nuclear Station License Nos. NPF-9 and'NPF-17 and that all statements and matters set forth therein are true and correct to the best of his knowledge.
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Hal B. Tucker, Vice President Subscribed and sworn to before me this 7th day of December, 1985 hm [-
No'tary Public My Commission Expires:
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ATTACHMENT II Trchnical Justification and Safety Analysis The proposed-changes are being submitted in response to Generic Letter 85-09,
" Technical Specifications for Generic Letter 83-28, Item 4.3". The changes add surveillance and testing requirements on existing components, and are expected to improve assurances that Reactor Trip Breakers (RTBs) will function as intended.
The changes include:
- 1. Table 3.3-1 is being revised to add an additional Action Statement to Item
- 19. Reactor Trip Breakers, and Item 20, Automatic Trip and Interlock Logic.
The Action Statement recognizes the dual trip function of the RTBs, Under-voltage (UV) and Shunt Trip Attachments (STA), and allows operation to continue, with one of those trip functions inoperable, for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> before the breaker must be declared inoperable.
- 2. Table 4.3-1 is being revised to require independent testing of the Under-voltage (UV) and Shunt Trip Circuits during the trip actuating device operational test of the Manual. Reactor Trip, function on a refueling-outage basis, and.cests of the UV and STA functions during monthly trip actuating device operational testing of the RTBs and Automatic Trip and Interlock Logic.
As noted, the changes do not modify existing components; nor do they reduce the offectiveness of any procedures or tests. Rather, the enhanced testing can
-r:asonably be expected to have a safety benefit in terms of assuring the continuing operability of the RTBs. The provision that one of the two (UV, STA) trip features in a breaker may be inoperabic for up to 48 hours5.555556e-4 days <br />0.0133 hours <br />7.936508e-5 weeks <br />1.8264e-5 months <br /> cannot be considered a significant dagradation of the ability to perform a safety function; any of three remaining trip functions (UV and STA on the redundant breaker and the operable function of the de-graded breaker) are available to provide a Reactor Trip.
Another change proposed in Generic Letter 85-09, relative to testing Bypass Trip Breakers (BTBs), is not included in this submittal. In the opinion of Duke Power, which is supported by Westinghouse and the Westinghouse Owners Group, there is no significant benefit which can be reasonably expected from inclusion of BTB testing in Technical Specifications. The limited amount of time that the'BTBs are actually in use, the-redundancy of the breaker function, and the normal maintenance and testing which are performed on the breakers all combine to create a sufficiently low proba-bility of BTB malfunction to obviate the need to include BTB surveillance in Tech Specs. Westinghouse has calculated the effect of testing frequency upon BTB unavail-ability, and the resultant probability of RPS unavailability. Increasing the testing frequency from every 18 months to bimonthly results in a reduction of BTB unavailability from 3.5 E-3 to 3.5 E-4, with a resultant reduction of total RPS unavailability from 1.3 E-9 to 1.3 E-10. This is a relatively insignificant contri-bution to a RPS unavailability of about 1.0 E-5. Increasing the probability of BTB fcilure from 0% to 100% results in an RPS unavailability increase of only 2.5%.
This contribution does not justify inclusion of the BTBs in Tech Specs. The staff apparently implicitly agrees with that position, because there are no Limiting Conditions for Operation (LCOs) acsociated with an inoperable BTB. It is Duke's
' ATTACHMENT II Page 2 position that if no.LCO is needed for an inoperable component, then no surveillance requirement should appear in Tech Specs. The maintenance and testing program asso-ciated with the BTBs has been established in accordance with Paragraph 2.c.(12) of 1FOL NPF-17, and is described in Duke Power's response to GL 83-28, dated November 4, 1983 (G.B. Tucker to D.G. Eisenhut). This program will continue, subject to modification based on additional reliability data and experience.
As a good practice, Duke will test the BTB prior to use to provide some degree of assurrance that it could operate. It'should also be noted that all breakers of this type are maintained by the same procedure regardless of whether or not they are installed as Reactor Trip Breakers. In fact breakers may see one period of service as RT Breakers and a subsequent period as Bypass breakers.
ATTACILMENT III SIGNIFICANT llAZARDS ANALYSIS In accordance with the requirements and criteria of 10 CFR 50.91 and .92, following is an analysis of the potential for significant hazards created by the proposed cmendment.
The proposed amendments would not:
Involve a significant increase in the probability or consequences of an accident previously evaluated; or Create the possibility of a new or different kind of accident from any accident previously evaluated.
These changes to surveillance requirements are intended and expected to increase the likelihood that the Reactor Trip Breakers will perform their intended function in the event of a challenge, and will not create or affect the possibility of any cccident.
The proposed amendments will not involve a significant reduction in a margin of safety.
The proposed amendments will not affect any margins of safety, either in terms of actpoints or radiation release limits.
Br: sed on the above, and upon the intuitive determination that the addition of testing and surveillance requirements will not degrade safety, Duke Power Company concludes that the proposed amendments do not involve a Significant llazards Consideration.
ATTACHMENT IV DELETION OF PARAGRAPil 2.c.(12) FROM NPF-17 As a result of various industry-wide failures, a concern arose throughout the industry and the NRC regarding the adequacy of surveillance and testing performed on Reactor Trip Breakers. As a result of this, McGuire Unit 2 had its Facility Operating License amended to address issues discussed in Section 7.2 of Supplement
.#7 to McGuire's Safety Evaluation Report (SER) relative to RTB testing and surveil-lance. These requirements are contained in Paragraph 2.c.(12) of NPF-17. However, these requirements are no longer needed.
Duke Power has responded to each of the items contained in paragraph 2.c.(12), as evidenced by the following comparison.
License condition (subparagraph of 2.c.(12)):
- 1) a. By June 3, 1983, the licensee shall provide a program plan for conducting a life-test of the undervoltage trip attachment. The life-test program is to be reviewed by the staff before implementation.
Response: This program was provided by letter dated June 3, 1983 from li.B. Tucker to !!.R. Denton.
- 2) b. The licensee shall modify the design of the automatic shunt trip of the main reactor trip breakers to install an independent fusing scheme. This modifi-cation shall be impicmented on a schedule consistent with the schedule re-quirements of the NRC Salem Task Force generic program.
Response: These modifications have been performed.
- 3) c. The licensee shall impicment the reactor trip breaker and reactor trip bypass breaker testing and reporting as described in Table 1.
f RTB testing is addressed cisewhere in this submittal. BTB testing will continue to be administratively controlled.
- 4) d. Within 60 days from issuance of this amendment, the licensee shall provide the upgraded post-trip review procedures for NRC staff review.
These procedures were provided by letter dated July 22, 1983 f rom II.B. Tucker to ll.R. Denton.
In addition, Duke Power responded to Generic Letter 83-28 by letter from !!.B. Tucker to D.G. Eisenhut, dated November 4, 1983.
In light of the foregoing discussion, it is considered that paragraph 2.c.(12) of NPF-17 is unnecessary and should be deleted, including Table 1.
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