ML20247E928
| ML20247E928 | |
| Person / Time | |
|---|---|
| Site: | McGuire, Mcguire  |
| Issue date: | 05/17/1989 |
| From: | Tucker H DUKE POWER CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| Shared Package | |
| ML20247E930 | List: |
| References | |
| TAC-71963, NUDOCS 8905260374 | |
| Download: ML20247E928 (3) | |
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. HAL II. TUCKEH reLeruoxe (704) 073-4531 twz reemment pout.r.4m em<.t orrum May 17, 1989 U.S. Nuclear Regulatory Commission ATTENTION:
Document Control Desk Washington, D. C.
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Subject:
-McGuire Nuclear Station Units 1 and 2 (TACs 71963/71964)
Mr. Darl S. Hood's letter dated April 17, 1989 requested additional information on the revised reactor vessel pressure-temperature limits proposed in my letter dated January 22, 1989. The April 17 letter contained four items on our proposed license amendment to revise the pressure and temperature limits in the McGuire Technical Specification 3/4.4.9 for heatup and cooldown of the reactor coolant system. Our responses to these items are provided below.
Item (1):
You propose to add to TS 3.4.9.1 references to five figures, including Figure 3.4-6.
Provide the proposed Figure 3.4-6.
Response
The reference to Figure 3.4-6 is-shown on the marked Technical Specification Page 3/4 4-30.
This reference was from an initial draft of the proposed technical specification revision which did contain an alternate curve desig-
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nated as Figure 3.4-6.
There is no Figure 3.4-6 in the new technical specifi-cation as we are currently proposing. A new, correctly marked, Page 3/4 4-30 t
is attached to this letter.
Item (2):
Why was Revision 2 to Regulatory Guide 1.99 not used as the basis for the Unit 2 limits and curves of proposed Figures 3.4-3 and 3.4-5 in accordance with NRC Generic Letter 88-11? Also, discuss the basis for your November 21, 1988 conclusion that "due to the design of the [ Unit 2] vessel, the limits being l
proposed based on Revision 1 are in fact conservative with respect to those that would have been generated had Revision 2 been utilized."
Response
GL88-11 states the licensees should use the methods described in Revision 2 to Regulatory Guide (RG) 1.99.
For McGuire Unit 2, Duke assessed whether to redo l
existing pressure-temperature limits and submit these within 1988 or to wait l
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U.'S. Nuclear; Regulatory Commission Page 2
.May 17, 1989 for the.next scheduled capsule withdrawal and use RG 1.99, Revision 2 at that time. Based on the assessment made as discussed in the response to the second part to this question, and because new limits would be available in the fall of 1990, using RG 1.99 Rev. 2, Duke concluded that the GL88-11 requirement to complete all actions "within two plant outages (approximately 3 years)" would be met by awaiting the results from the next capsule analysis.
(Three years from the RG issuance is about May 1991. The revised capsule results will be implemented in late 1990).
The statement from the Duke November 21, 1988 letter goes on to state that continued use of Revision 1 for the interim period (emphasis added) until the next capsule is removed and analyzed, is acceptable.
For the interim period of time, until capsule results and curves are available in 1990 from a capsule being removed from McGuire Unit 2 this summer, the proposed curves, based on RG 1.99, Revision 1 are very similar-to those that could be calculated using RG 1.99, Revision 2.
This was based on a omparison of RT values.
NDT The proposed curves have an RT f 85 F at 1/4 T at 8 EFPY and are based on RG 1.99, Rev. 1.
Currently,IdTuire Unit 1 is at about 4 EFPY.
By the time the next capsule results are available (third quarter 1990), McGuire Unit 2 I"8 will have about 5 EFPY. Using the chemistry, fluence, and initial RT t 5 EFPY is akT ** bout N
from WCAP-11029, and RG 1.99, Rev. 2 an estimated RT so a NDT 85'F.
Thus, it was concluded that at 5 EFPY, the proposed curves are essen-tially the same as those that would be developed using RG 1.99, Rev 2.
It was also concluded that at 8 EFPY, the RT shift using RG 1.99, Rev. 2 would be greaterthanthatusingRG1.99,Rev.kT Thus, the commitment was made to provide new Unit 2 curves, based upon RG 1.99, Rev. 2, promptly following completion of the analysis of the capsule.
It was not meant to imply that the RG 1.99, Rev. I curves were always conser-vative to the RG 1.99 Rev. 2 curves; rather the intention was to convey conser-vation over the limited period of time until new capsule results and new curves using RG 1.99, Rev. 2 would be available.
Item (3):
You state that the new curves for the proposed TS do not contain the 10 F and 60 PSIG margins for possible instrument errors shown in Westinghouse curves because " approved station procedures" will be used to account for the appli-cable instrument error.
Identify these approved station procedures and sum-marize how they account for instrument error.
Response
Control room personnel utilize the Data Book, approved procedure OP/1 or 2/A/6100/22, Enclosure 4.3 curves 1.5 and 1.6 to control heatup and cooldown within the necessary pressure and temperature limits. This procedure will continue to include the instrumentation margin. The Data Book provides opera-tor guidance which includes margin for instrument error.
However, in order to expedite the NRC staff review and approval of this technical specification amendment, we are retaining the 10 F and 60 PSIG margins. New curves with the margin allowance are attached to this letter for inclusion with the proposed amendment submittal of January 22, 1989.
U. S. Nuclear Regulatory Commission Page 3.
May 17, 1989 Item (4):
Comparison of existing TS 3.4.9.1.b with proposed Figure 3.4-4 shows that the maximum cooldown rate for Unit I would be changed from its present limit of 100 F per hour to 50 F per hour.
To what extent would this slower cooldown affect station radiological releases for events such as those controlled by Abnormal Operating Procedure AP/1/A/5500/10 "NC System Leakage Within the Capacity of Both NV Pumps"?
Response
The proposed Fi.gure 3.4-4 shows the normal cooldown rate for Unit 1.
Under normal cooldown conditions, McGuire has an administrative limit of 50 F per hour. During abnormal events a higher cooldown rate may be used.
Please see my response to the McGuire Unit I steam generator tube rupture event AIT report / confirmation of action letter dated April 26, 1989 (Attachment 6, page 3 of 4, Item 6).
In this item I indicated this enhancement would be added to AP/1,2/A/5500/10 in a change to be completed by May 1, 1989. This was dis-cussed with the NRC staff on April 13, 1989 and again on May 5, 1989. There-fore no increase in radiological releases is foreseen as a result of the 50 F per hour administrative limit on cooldown since cooldown under abnormal condi-tions can proceed at a higher rate.
Please contact J. S. Warren at (704) 373-2627 if further information is needed on this item. We are very interested in the prompt resolution of any issues that may delay the approval of this technical specification.
Very truly yours, a B.E
')lWV H. B. Tucker
.xc: Regional Administrator Mr. P. K. Van Doorn U. S. Nuclear Regulatory Commission NRC Resident Inspector Region II McGuire Nuclear Station 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. Dayne Brown, Chief Radiation Protection Branch Division of Facility Services Department of Human Resources 701 Barbour Drive Raleigh, NC 27603-2008 Mr. Darl Hood, Project Manager Office of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
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