ML20215L932
| ML20215L932 | |
| Person / Time | |
|---|---|
| Site: | Zion File:ZionSolutions icon.png |
| Issue date: | 05/12/1976 |
| From: | Purple R Office of Nuclear Reactor Regulation |
| To: | Bolger R COMMONWEALTH EDISON CO. |
| Shared Package | |
| ML20215L916 | List: |
| References | |
| NUDOCS 8610290377 | |
| Download: ML20215L932 (6) | |
Text
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,71[, g%ok NUCLEAR REGULATORY COMMISSION UNITED STATES
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WASHINGTON, D. C. 20555 r
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May 12, 1976 Decket Nos. 50-295 and 50-304 Co: onwealth Edison Company ATIN:
Mr. R. L. Bolger /
Assistant Vice President P. O. Box 767 Chicago, Illinois 60690 Gentlemen:
Re:
Zion Station Units 1 and 2 The Cc==ission has issued the enclosed Amendment No. 20 to Facility License No. DPR-39 and Amendment No. 17 to Facility License No. DPR 48-for Zion Station Units 1 and 2, respectively. The amendcents consist of changes to the Technicsl Specifications and are in response to your applications dated ie, rancer 3 and 6,1974 and March 16, 1976, as supple-mented Dececoer 9,1974, April 18, 21, July 9, August 18, Septecoer 16, October 6, November 17, 1975, January 5, April 15, 19, 21, 30 and May 4 and 5, 1976.
These amendments (1) revise the operating limits in the Technical Specifi-cations based upon an acceptable evaluation model that confor=s to the requirements of 10 CFR 50.46, (2) terminate restrictions imposed on the facilities by the Commission's December 27, 1974, order for Modification of Licenses, ana (3) revise operating limits in the Technical Specifications for operation of Zicn Unit 1 in fuel cycle 2.
Copies of tne Safety Evaluation and the Federal Register Notico are also l
enclosed.
i Sincerely,
/
2 RobertA. Purple,dhief Operating Reactors Branch #1 Division of Operating Reactors
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i Enclosures and cc:
l See next page l,
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ADOCK 05000295 PDR i
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- E N W
.,I JO In compliance with the Order, on April 21, 1975, the licensee submitted a partially revised evaluation of ECCS performance and revised proposed Technical Specifications to assure operation in conformance with 10 CFR 50.46.
Subsequently, the licensee proposed other minor revisions andIn supplements to the proposed Technical Specifications and analyses.
addition, various aspects of the performance of ECCS cooling systems were discussed at a meeting of the staff with Commonwealth Edison representatives in Bethesda, Maryland on July 24, 1975 A detailed list of the licensee's proposals and of other documents used by the staff is contained under
" References " below.
Evaluation of ECCS Parformance The licensee's submittal of April 21, 1975 perfor=ed a large break LOCA analysis for a spectrum of three guillotine breaks which were specific for To supplement the analysis of the three breaks, the Zion Units 1 & 2.
licensee referenced WCAP-8356 " Westinghouse ECCS-Plant Sensitivity Studies,"
The small and WCAP-8339 "destinghouse ECCS Evaluation Model - Summary."
break analysis was previously submitted using an acceptable model.
The analyses, which were performed assuming a total peaking factor, F,
Q of 2.25 and 2.20 for Units 1 & 2 respectively, and identified the worst break size as the double-ended cold les guillotine break witn a Moody multiplier 0
The calculated peak cladding temperature was 2200 F, as specified of 0.6.
The maximum local metal / water reaction of 9.03; and 9.99%
in 10 CFR 50.46.
for Units 1 & 2 respectively is within the allowable limit of 175; the total core wide metal / water reaction of less than 0 3% for both Units 1 & 2 l
is well below the allowable limit of 15 The small break LOCA analysis submitted on September 3,1974 included a three break spectrum analyses and identified the 6-inen pipe break as the limiting small break with a peak cladding temperature of 1463 F and demon-strated that the small break LCCA is not the limiting break size.
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Since the analyses provided by the licensee evnsidered only four loop l'
operation, the Zion licenses have been appropriately conditioned to restrict r
l operation with less than four loops operating.
j 19, 1976, a revised small break analysis was provided By letter dated April The licensee proposed revising the K(Z) third line coordinate for Zion Unit 1.
Since the peak to provide operational flexibility fer Zion Unit 1 Cycle 2.
cladding temperature developed during a small break LOCA is a function of power in the upper region of the core, the small break was reanalyzed.
l The six inch diameter break, which is the limiting size small break, was reanalyzed using the approved version of the WFLASH and LOCTA-W computer codes in conjunction with a power distribution that is skewed toward tne l I*s I
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Y (Q
Westinghouse Water Reactor
== Fuemen Electric Corporation DMslons m asi2 Pmsburp Pemy%rna 15230 May 21,1982 82CW*-G-080 Mr. H. E. Bliss Director Commonwealth Edison Company KEYWORDS-Nuclear Fuel Services ZION Room 922. Edison Building FAC 72 L'est Adams Street Chicago, Illinois 60603
Dear Mr. Bliss:
COPHONWEALTH EDISON PROJECT ZION NUCLEAR POWER PLANT K(2) L0CA ENVELOPE'FOR IION The following procedure describes the method for construction of the (small break analysis) third line segment of the maximum Fo(Z) X Power i
operating envelope for the Zion Units 1 and 2.
The coordinates.of the -
third line segment are given by:
Fg = 2.18 at 10.8 ft, and FQ = 1.42 at 12.0 ft.
The 10.8 ft. value is comon to the standard 2.32 envelope (see for example, WCAP-9500 figure 4.3.21). The 12.0 ft. Fo value was obtained from a Zion specific small break analysis. This third line segmenti, ras-
- i e defined by the above coordinates, remains common to any revised ~LOCA: limits.
Zion is currently constructing the third line segmenf u*ing a slightly more conservative slope.
It is recommended that the above procedure be adopted l
for any future revisions to the Zion technical specifications due to changes i
in the LOCA limit. This will provide additional available Fo margin under the third line segment for future FAC analyses which may be required for 18-month cycles in coastdowns.
If questions arise, please call.
Sincerely, 9. W. ~7 h c Cr-_ % __
J. M. McCorkle
/mh Project Engineer NFD Projects cc:
L. H. Fitzpatrick
=84+F4 Homsenw W. D. T'Niemi C. M. McKenzie - W Chicago Sales
ATTACHMENT 3 EVALUATION OF SIGNIFICANT HAZARDS CONSIDERATION PROPOSED CHANGES TO ZION TECHNICAL SPECIFICATION APPENDIX A - FIGURE 3.2-9 NORMALIZED HOT CHANNEL FACTOR DRGCRIPTION OF AMENDMENT REOUEST An amendment to the Zion Facility Operating License is proposed to correct an error in Figure 3.2-9, Hot Channel Factor Normalized Operating Envelope for Units 1 and 2.
BACKGROUND 10 CFR 50.92 states that a proposed amendment will involve a no significant hazards consideration if the proposed amendment does not:
(1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety.
I In addition, the commission has provided guidance in the practical applica-l tion of these criteria by publishing eight examples in 48 FR 14870.
The discussion below addresses each of these three criteria and i
demonstrates that the proposed amendment involves a no significant hazards consideration.
BASIS FOR NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION Does the proposed amendment (1) Involve a significant increase in the probability or consequences of an accident previously evaluated; or 1
(2) Create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) Involve a significant reduction in a margin of safety?
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. DISCUSSION - ITEM #1 This change involves correcting an error in the upper core line segment of the Normalized Hot Channel Factor (K[z]) curve. This conservative reduction has the effect of restricting the allowable power densities in the upper 1.2 feet of the core to ensure that the core is operating within the bounds of Zion's safety analyses. This restriction ensures that all postulated Loss of Coolant Accidents (LOCA) will produce results that are bounded by the current LOCA analyses.
In addition, the correction of this error has no effect on probability of a primary system pipt rupture, which is the accident of interest. There is no relationship between the allowable power density in i
the upper 1.2 feet of Zion's reactor core and the integrity of the reactor coolant system.
Thus, this proposed amendment has no effect on the probability or consequences of any previously evaluated accident.
DISCUSSION - ITEM #2 The reduction in the allowable power densities in the upper 1.2 feet of Zion's reactor cores have no effect on any of Zion's systems.
In addition, this power produced in this region is transmitted directly to the surrounding coolant. Thus, a slight reduction in the local heat transfer to the reactor coolant will not produce any effects or pertubations that might induce the failure or malfunction of another component.
I Finally, this proposed change is actually more conservative than the current, erroneous Technical Specification. Thus, the exclusion of a small segment of operating flexibility cannot have any effect on plant operation.
Based upon the above discussion, this proposed change will not l
create the possibility of a new or different kind of accident from any l
previously evaluated.
DISCUSSION - ITEM #3 This proposed change is more conservative than the current Technical Specifications. It will require the maintenance of lower power densities in the upper core regions than is currently allowed. However, this change will also correct an error in the Technical Specifications, making it consistent with the assumptions contained in Zion's safety analyses.
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O Thus, the margin of safety will be increased to a level consistent with Zion's LOCA analyses as a result of this change.
This proposed change corrects an error in the current Figure 3.2-9.
Thus, example (i) is applicable in this instance. Example (i) states:
(i) A purely administrative change to Technical Specifications: for example, a change to achieve consistency throughout the technical specifications, correction of an error, or a change in nomenclature.
Therefore, since the application for amendment satisfies the criteria specified in 10 CFR 50.92 and is similar to examples for which no significant hazards consideration exists, commonwealth Edison Company has made a determination that the application involves no signficant hazards consideration.
2038K
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