ML19259C482

Effect of Closing Oconee Nuclear Plants on Ability to Meet Summer Peak Demands.

ML19259C482
Person / Time
Site:	Oconee
Issue date:	05/09/1979
From:	Taylor V UNION OF CONCERNED SCIENTISTS
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ML19259C480	List: ML19259C479 ML19259C481 ML19259C482
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NUDOCS 7906220170
Download: ML19259C482 (10)

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AFFIDAVIT OF VINCE TAYLOR I, Vince Taylor, hereby make my affidavit as follows:

I prepared the attached, "The Effects of Closing the Oconce Nuclear Plants On the Ability to Meet Summer Peak Demands." It is true and accurate to the best of my knowledge and belief.

Signed under the pains and penalties of perjury:

Vince Taylor Union of Concerned Scientists May 9, 1979 2281 031 7906220l7d

'inc e ay or Union of Concerned Scientists May 9,1979 (301)'421-9245 THE EFFECT OF CLOSING THE OCONEE NUCLEAR PLANTS ON THE ABILITY TO MEET SLSMER PEAK DEMANDS SLSMARY The decision of the Nuclear Regulatory Commission to allow the Oconee nuclear units built by Babcock and Wilcox to continue to operate was influenced by testimony and information indicating that the absence of these units could lead to an inability of the affected region to meet peak summer demands. There were, however, numerous errors and misleading statements in the testimony and information submitted to the Commission. When errors of fact are corrected, the available data show clearly that electric supplies available to the affected region would be adequate to meet peak demands without any contribution from the Oconee 1, 2, and 3 units or the Surry 1 and 2 units (presently ordered closed because of deficiencies in seismic stress codes).

RESERVE PJ.EGINS A major source of information for the Nuclear Regulatory Commissioners was a document entitled " DOE Information on Reserve Margins,"* referred to hereafter as Ref. 1. The first page of the covering memorandum on Ref. 1 (see Attachment A to this report) provided a brief summary in the form of an un-titled table, referred to hereaf ter as Table A.

Ref.1 and, especially, Table A, provide an extremely misleading picture -

of the adequacy of electric supply in the absence of the B&W nuclear units. A major reason for this is that Table A reports reserve margins on a basis that differs marked 1v from common oractice. As usually defined, reserve margins refer to the excess of planned available generating capability (af ter allowing for scheduled repairs) over predicted peak load (expressed as a percent of peak load). They may'be termed " capability reserve margins." Table A, however, displays " operating reserve margins," sometimes termed " spinning reserve margins."

Planned operating margins are always much smaller than desired capability margins. .

• " Doe Information on Reserve Margins," submitted by Al Kenneke, Acting Director of the Of fice of Policy Evaluation of the Nuclear Regulatory Commission, dated April 24. (Ref. 1.)

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'- Desired capability reserve margins are generally in the range of 15 to 20 percent (and are smaller for systems with smaller average unit size and lower forced outage rates). Part of this margin is to allow for unplanned failures of equipment (commonly referred to as " unscheduled or forced outages"), some af which may not be repai'able r for an extended period. Typically, five to ten per-cent of scheduled capability might.not be available at the time of the summer peak because of equipment malfunction. The remainder of the capability reserve margin provides an allowance for an operatine reserve margin.

I'lanned operating reserve margins are much lower than desired capability reserve margins because they are intended only to handle very short-term (measured in minutes) fluctuations in generating capability and load. For example, in the ECAR region of the National Electric Reliability Council (NERC),

the spinning reserve it the time of the 1978 summer peak was 2359 FM, gompared to a peak load of 59,866 Fr.i, providing an operating reserve margin of 4%.

• The operating reserve policy of the Virginia-Carolina (VACAR) region, which includes Duke Power, is for each of the 6 largest utilities in the region to maintain an operating reserve of 4 percent cf peak load plus S percent of their largest unit.**

Assuming that the largest unit in all cases is 1200 FFi, the desired operating re-serve for the summer of 1979 (expected peak of 28,282 BN) would be 1707 MU, or an operating reserve margin of 6 percent.

Table A Misleading The text on page 1 cf Ref. 1 (see Attachment A) states that "Utilites typically prefer to maintain a 15 to 20% reserve margin." This statement refers to a canabili*y reserve margin, but the last column titled " margin after shut-down" (of all B&W reactors) shows capacity estimated to be available to provide an operating reserve margin; that is, an estimate of probable unscheduled outages has already been subtracted f rom the estir..ated available capacity in preparing the " reserve margins" shown in Table A. This very unusual procedure makes the

• "ECAR Load and Capacity Appraisal, Winter 1978-79," 78-GRP-33A, November

• 1978 (Ref. 2). The report notes that "The spinning reserve was mai.ntained above the level required by ECAR Document 2 . . . . (p . 25)

• • "SERC Coordinated Bulk Power Supply Program',' April 1,1979 (Ref. 3. The rule for Vepco is slightly di,fferent from'but essentially equivalent to that of the other .5 utilities. .

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.. 3-table extremely confusing and misleading (as is evident from the testimony of Dennis Rathbun on April 25, 1979, discussed below). The figures given there should be cocpared with the typical goal of providing an operating reserve cargin of 4 to 6 percent.

Errors in the Calculations of Reserve Margins The eisleading inferences that seem likely to be drawn from Table A are compounded for the VACAR electric region, which includes the Oconee units, by two errors:

1. ) In calculating the operating reserve margin E5 )wn in Table A for VACAR (line 2), Oconee l'was, in effect, subtracted twice from the gross generating capability. This occurred because Oconee 1 (860 Fal) was already included in the " planned outage" estimate of 1104 th' for VACAR used to first adjust gross available capability.* Then, in calculating the ef f ects on reserve capacity of shutting down the B&W plants, Oconee 1 (860 >ni) was once again subtracted from the scheduled available capability. Correcting for tnis error, the estimated capacity available for operating reserve within VACAR becomes 34? MW, or 1.2 percent of the estimated peak 1 cad. The correct capability reserve margin is 11.8 percent.

2.) A serious arithmetical error was cade in converting the estimated mega-watt reserves including potential imports into percentage reserve margins.

Table A shows this supplemented operating reserve to be 4564 137 for VACAR and then translates this into a reserve margin of 7.5%, but the correct numerical calculation would yield 16.3 percent.

Correcting for the double countinc of Oconee 1, the correct supplemented capacity available for operating reserves is 5444 FM and the correct operating reserve mar-gin is 19.2 percent. The correct, supplecented capability reserve margin is 30 percent, far above the 15 to 20 percent levels cited by DOE as adequate to provide reliable electric service. Thus, the data provided in Ref. 1, when corrected and pro} crly interpreted, provide no indication that electricity supply within

• See p. 3 of Ref. 1. The 1104 FSJ figure in Ref. I was taken f rom Ref. 3. The inclusion of Oconee 1 in this scheduled outage was confirned by the VACAR coordinator, Wilson W. Morgan, Carolina Power and Light, telephone conver-sation, April 30'and May 2, 1979.

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., the VACAR region would be inadequate if all Oconee units were to be closed.

T_estimony of Dennis Rathbun On April 25, 1979 Denni's Rathbun (listed as the " Contact" on page 1 of Ref. 1) appeared before the Nuclear Regulatory Commissioners to explain the

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docu=ent reviewed above', " DOE Information on Reserve Margins" (Ref.1). That this document misled at least one Commissioner is clearly indicated by

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introductory remarks of Chairman Hendrie:*

I would also note that the report which we have through from (sic)

Dennis Rathbun, who has been collecting some things, notes that the power supply situat' ion is indeed going to be a critical one if all the units are shut down.

Mr. Rathbun's report on reserve margins relates to summer peak conditions. We are not there now, but at summer peak conditions some of the recions, the Reliability Council regions, vill in fact go negative on reserve capacity. it is, then, one of those situations 91 which ahe public interest requires fairly precise judgement. (Emphasis added.)

On the conmonly accepted definition of reserve capacity (scheduled available capacity less estimated peak load), none of the nine Reliability Regions of the United States would be brought close to a negative reserve position by the shutdown of the B&W units (which should be obvious on its f ace, since the units in question total only 6833 FN,1.1 percent of the total generating capacity of the United States scheduled to be availabic at the time of the 1979 summer peak **). Of course, af ter making a conservatively large estimate of possible forced outages and subtracting this from scheduled capacity as was done in Ref. 1, one would expect the remaining reserves'to be fairly close to zero (about 5 perce6t in regions where total capacity was near to desired levels). If one then takes a smaller sub-region of a Reliability Council Region and subtracts several thousand megawatts of nuclear capacity, the remaining figure may

• Transcript of proceedings before the Nuclear Regulatory Commission entitled

" Continuation of Briefings on Principal Factors Related to Current Status '

t of Operating Plants," April 25, 1979 (Ref. 4).

I ** As estimated by the National Electric Reliability Council, "The 8th- Annual s

Review of Overall Reliability and Adequacy of the North, American Bulk Power Systems," August 1978, Appendix A-3,*

p. 22. (Ref . 5) .

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'- well f all below the projected peak load within the sub-recion. This, however, is exactly the circumstance for which the transmission interties within and between Reliability Regions were established; thus the negative figures of Ref. 1 did not imply, as Chairman Hendrit stated, "that the power supply situ-atica is indeed going to be a critical one if'all these [B&W] units are shut down." Indeed, wherever the table in Ref. 1, page 1, allowed for potential transfers it showed remaining capacity to be more than sufficient to provide the desired operating reserves of 4 to 6 percent.

The initial rais-impression ~ created by Ref.1 was compounded by Mr. Rathbun's testimony on April 25. When Ccmmissioner Gilinsky queried Mr. Rathbun about the reserve margins given in Table A, Ref. 1:*

CommisFioner Gilinsky: What would be the typical margins in unaffected [byashutdownofB&Wreactors] areas,unaffectedregions?

Mr. Rcthbun: I would assume they would be 15, 20 percent, perhaps more. The planning margins--

Commissioner Gilinsky: Are the numbers comparable to your last column?

Mr. Rathbun: For the operating reserve margins, assuming, as I say, 5 to 11 percent,**then if they were running 20 percent planned, then they should be runninc. let's sav, somewheres betweta 10 and 15.

(Emphasis added.)

This was Mr. Rathbun's last word on " normal" operating reserve margins; thus the Commissioners were led to believe that " operating reserve margins," those given in Table A, Ref.1, "should be running" between 10 and 15 percent, whereas the correct numbers are 4 to 6 percent. ,

That Mr. Rathbun, himself, was misled by the errors and confusions of Table A is clear from his response to a query by Commissioner Ahearne as to whether some of B6W plants were "likely to have a much greater impact being shutdown than

• Ref. 4, pp. 30, 31.

• • Here Mr. Rathbun is referring to an estimate of typical rates of unscheduled outages provided on page 1 of Ref. 1 (with a typographical error, the omission of the word " outages," that makes the estimate obscure to the non-expert).

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.. others?"*

Mr. Rathbun: This would only be a judgement on my part, Commissioner, but I guess my own feeling would be that VACAR can be rather serious.

Since Table A shows a " reserve margin", including potential imports, of 7.5 percent for VACAR (rather than the correct figure, based on Table A's assumed level of imports, of 19.3 percent), and since Mr. Rathbun-had stated his belief that these reserve margins ought to be in the range of 10 to 15 percent (rather than the correct range of 4 to 6 percent), his erroneous interpretation of the true situation is quite understandable.

In relying upon Mr. Rathbun for testimony on the adequacy of electricity supply, the Commission was apparently relying on a person with very little prior experience in this complex field and who had insufficient time to carefully check the information provided to him.**

ADE0CACY OF SUPPLY IN DUKE POWER AREA The 3 Oconee units are all located in the service area of Duke Power.

Although the data in Ref. 1 indicate that the VACAR region in which Duke power is located would have sufficient potential supply to avert shortages during the summer peak, closing of the Oconee units could possibly create more serious supply problems for Duke Power. In testimony before the Nuclear Regulatory Commission, the Fresident of Duke Power, stated in no uncertain terms that this, indeed, would be the case:***

• Ref. 4, p. 39

• • Mr. Rathbun's lack of experience is suggested by his reply to a question as to whether the peaks used in calculating reserve margins were last summer's peak or a projected peak for the coming summer. He replied, "My understand-ing is that they would be projected peaks for this summer, rather than just taking last summer. Again, T can't vouch for that...." (Ref. 4, p. 40).

But anyone who had reviewed any National Electric Reliability Council -

doc -met t on reserve margins ought to have been able to vouch absolutely that this was the case.

• • • Ref. 4, pp. 56-57. '

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In July we'll be 2100 megawatts deficient in meeting its [the system'f] load, and in August we'll be 3000 megawatts deficient in meeting its load.... With that type of deficiency, and having checked with all of our neighboring utilities and their neighbors on resources available with the advent of warm weather, upon the arrival of summer weather it is highly probably (sic) that we will go into a rotating blackout eck 4 we have notified the officials of both states of.that probabild y , if we have to shut down Oconee.

What Mr. Lee failed to men *i is the existence of sufficient transmission intertie capacity for Duke Power to import 1000 megawatts more eldctricity than the estimated maximum shortfall.*

Supplies to Duke from Within VACAR According to the information supplied by DOE in Ref.1, much of the power required by Duke to meet its summer peak could be supplied from within*VACAR, its own power pool. Table A (Attachment 1), when corrected, implies that VACAR would need only 1350 >G7 of imports to provide a 6 percent operating reserve at the time of the summer peak.**

Surolies to Duke f rom Within SERC Electricity requirements of Duke not supplied from within VACAR could almost certainly be supplied from other sub-regions of the Southern Electric Reliability Council (SERC). Excluding the three Oconee and two Surry nuclear plants and the belewse Creek coal plant, SERC would still have an 18 percent reserve margin of scheduled available capability (102,867 MW) over projected peak load (87,109 MW).***

This is in the range generally considered adequate to insure reliable service.

TVA, one of the sub-regions of SERC, is scheduled to expart 1760 MW of power outside of SERC. -If not destined for regions with low reserves, this export could be rescheduled within SERC to further assure system reliability.

Moreover, TVA is scheduled to supply 1300 MW of power to U.S. enrichment facilities

• Ref. 1, p. 1, states in footnote 2, " Transmission lines to Duke Power could permit import of 3950 MWe (absolute maximum)." Note: MWe stands for megawatt-electric and is used interchangably here with MW. .

• • Operating reserves within VACAR would be 347 MW (af ter correcting for the double counting of Oconee 1); thus 1350 MW of imports would be needed to raise these reserves to 6 percent of the estimated summer peak of 28,282 MW.

• • • Ref. 3, Item 3-A for SERC.

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• . this summer. There'is presently a large surplus of enriched fuel in the government stockpile; thus the power scheduled for enrichment could be tempor-arily transferred to VACAR without any risk of creating nuclear fuel shortages.

As shown below, the ability to transmit this power is not a limiting factor.

TRANSFER CAP!.BILITIES INTO VACAR ,

Total transfer capabilities into VACAR, including emergency transfer capabilities (which can be sust'ained f or several days *) of 4800 MW, are estim-ated to total 14,900 mD**

Table 1

ransfer Capabilities to VACAR^

(Megawa - O Exporting Installed t ergency Total Region Interconnection Transfer Capability Capability Southern 1800 1000 2800 TVA 2300 1700 4000 ECARb 3000 1200 4200 c 3000 900 3900 MAAC Totals 10100 4800 14900 Note: a. Member of the Southern Electric Reliability Council

b. East Central council region c. Mid-Atlantic council region The total transfer capability into VACAR is more than ten times the estimated maximum level of imports (1300 MW) required to maintain a six percent operating reserve within VACAR at the summer peak. Note especially that the

• See Ref. 5, p. 19, f'or the official definition of Ecergency Transfer Capability.

• • Ref. 3, Item 6-A, pp. 43-45. Listed values are in addi, tion to scheduled transfers. ,

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transfer capability 'f rom TVA to VACAR' is listed as 4000 FRJ. This indicates that Mr. Lee was either misinformed or less tnan totally forthcoming in his appearance before the Commission when, in discussing power supplies available to Duke, he stated, "There are no ties between VACAR and TVA."*

The large transfer capabilities shown in Table 1 imply that VACAR would have substantial flexibility in obtaining necessary imports both from within SERC and from other regions, all of which would have comfortable reserve margins without the B&W nuclear plants.

CONCLUSION Contrary to the evidence and testimony provided the Nuclear Regulatory Commission, closure of the three Oconee nuclear units would not create a danger of " rotating blackouts" in areas served by Duke Power. Sufficient generating and transmission capability exists within the Duke power pool region and adjacent regions to supply Duke with more than their maximum estimated deficit.

• Eef. 1, p. 56. This apparently was said to ccrrect" a previous statement by Dennis Rathbun that VACAR had "some degree of interconnect with TVA. I can't think it's as strong as with some other utilities." (Ref. 5, pp.

31-32.)

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