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Proposed Findings of Fact & Conclusions of Law in Response to CA Energy Commission 800804 Findings.Sufficient Actions & Mods Implemented Per Commission 790507 Order Sufficient. Certificate of Svc Encl
	ML19331E302
Person / Time
Site:	Rancho Seco
Issue date:	09/05/1980
From:	Baxter T, Traviesodiaz, Traviezodiaz; SACRAMENTO MUNICIPAL UTILITY DISTRICT, SHAW, PITTMAN, POTTS & TROWBRIDGE
To:	;
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ML19331E301	List: ML19331E300; ML19331E302;
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	ISSUANCES-OM, NUDOCS 8009090788
	Download: ML19331E302 (58)
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BEFORE THE ATOMIC SAFETY AND LICENSING BOARD y

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SACRAMENTO MUNICIPAL UTILITY DISTRICT

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Docket No. 50-312

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(Rancho Seco Nuclear Generating

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-LICENSEE'S REPLY TO THE PROPOSED FINDINGS -OF FACT AND CONCLUSIONS OF LAW OF THE CALIFORNIA ENERGY COMMISSION AND THE NRC STAFF SHAW, PITTMAN, POTTS & TROWBRIDGE Thomas A. Baxter Matias F.

Travieso-Diaz Counsel for Licensee September 5,.1980 l

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TABLE OF CONTENTS Page I.

INTRODUCTION 1

II.

PROPOSED BACKGROUND STATEMENTS 2

III. PRO POS ED F INDINGS OF FACT.............................

6' A.

Integrated Control System........................

6 B.

Feedwater Transients 12 C.

Once Through Steam Generator Sensitivity................................. 13 D.

Natural - Circulation, Void Fo rmation, and Small-Break Loss-of-Coolant Accidents 15 E.

Auxiliary Feedwater System Reliability........... 18 F.

Safety System Challenges 25 G.

Operator and Management Com p e t e n c e.................................. 28 H.

Instrumentation 37 I.

Hydrogen Control 37 J.

Controlled Filtered Venting 39 IV. - PROPOSED CONCLUSIONS OF LAW 51

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September 5, 1980 UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of

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SACRAMENTO MUNICIPAL UTILITY DISTRICT

)

Docket No. 50-312

)

(Rancho Seco Nuclear Generating

)

Station)

)

_ LICENSEE 'S REPLY TO THE PROPOSED FINDINGS OF FACT AND CONCLUSIONS OF LAW OF THE CALIFORNIA ENERGY COMMISSION AND THE NRC STAFF I.

INTRODUCTION 1.

Licensee herein submits its reply to the

" California Energy Commission's Proposed Findings of Fact and

' Conclusions of Law in the Form of an Initial Decision," datci August 4, 1980,1 and ' to the "NRC Staff's Proposed Findings of Fact and Conclusions of Law in the Form of an Initial Deci-sion," dated August 22, 1980.

Licensee has not attempted to 1: The accompanying " Statement of the California Energy Commission in Support of its Proposed Findings of Fact and Conclusions of Law," does not meet the requirements of 10 C.F.R.'S 2.754 and, accordingly, Licensee will not reply to the " statement."

respond here to each proposed finding and conclusion with which Licensee disagrees or to note -where there is substantial agreement among the parties.

Where the disagreements are plain and the positions are accompanied by accurate citations to the record, we have not repeated, but rely upon " Licensee's Proposed Findings of Fact and Conclusions of Law in the Form of an Initial Decision," dated July 11, 1980.

2.

Licensee's reply is set forth in the form of a section of a proposed initial decision in which the Board address ~es the proposed findings of fact and conclusions of law filed by the parties.

Proposed findings of fact are cited as "PF [ paragraph number]."2 3.

Licensee's reply' includes.. separate memorandum of law which addresses the procedure to be followed by the Board if it should wich to recommend adoption of any of CEC's proposed modifications to the Commission's Order of May 7, 1979.

II.

PROPOSED BACKGROUND STATEMENTS 4.

The proposed background statements filed by the parties are generally consistent, although CEC's discussion (CEC 'PF 4-7). ignores the undisputed facts that this hearing was 2

The paragraphs in CEC's proposed conclusions of law are separately numbered ' and will be cited as "CL [ paragraph number]. "..

discretionary, that the Commission's Order of May 7, 1979, did

_not direct that a hearing be held, and that. the hearing was

-held only because it was requested by petitioners who met the requirements of 10 C.F.R. S 2.714.

See Licensee PF 8-14; Staff PF 1-4.

5.

CEC's proposed initial decision is unique among those filedL in that it characterizes all of the issues in this proceeding as " contested."

See CEC Table of Contents, PF 25, and headings throughout.

It is fundamental, however, that a

" controversy" requires a dispute between two or more parties.

Yet CEC has not identified the proponent ( s) of the issues which it labels " contested."

Certainly Licensee and the NRC Staff did not endorse the rarits of any contested issue, and CEC scrupulously declined to do so.

It is equally clear that in posing questions prior to the hearing the Board cannot be viewed, as CEC apparently would have it, to be taking a position on the matters before it.

Indeed, a question, by its very form and nature, does not assert a position.

The Board,

then, without hesitation endorses the description of the issues by Licensee and the NRC Staff.

See Licensee PF 26, 27; Staff PF 10.

6.

CEC, in its proposed findings 22-24, falsely accuses Licensee of suggesting a change in the Board's earlier rulings allocating _the burden of proof, and then proceeds itself to suggest a new standard.

Licensee and the Staff accurately recited thef Board's holding, in its Prehearing

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Conference Order' of August 3,1979, that the burden of proof on all contentions would be:placed upon Licensee and the burden of going forward on contentions would be placed' upon the party making the cont'ention.

See Licensee PF 24; Staff PF 4.

Licensee has not suggested a reallocation of these burdens, but has merely observed the obvious change in the posture of the proceeding which developed shortly before the start of the evidentiary hearing -- namely, the withdrawal' of all of the proponents of the contentions.

It is CEC, and not Licensee, which now proposes to expand the Board's holding of August 3, 1979, which explicitly applied to contentions.

CEC proposes, at PF 24, that ".

the ultimate burden of proof rests on the Licensee or. all issues in this proceeding."

For the reasons so forcefully argued by CE, the Board declines to entertain CEC's untimel_ and unwarranted post-hearing reconsideration of our pr wious ruling.

7.-

The proposed findings tendered by CEC include that party's account of conversations, discussions and 4

so-called " negotiations" which preceded the Commission's Order of May 7, 1979.

See, e.g.,

CEC PF 11-13, 50, 61, 67, 68, 328, 329, 331.

These statements apparently are designed to support the following observations in CEC proposed-finding 30:

The short-and long-term requirements of the May 7 Order were not decided upon after careful analysis of necessary steps to improve Rancho Seco's safety.

Rather, they were devised virtually overnight with a premium on actions that could be completed rapidly and thus ensure prompt restart of the facility.

It therefore is evident that the public interest was.

I poorly served by.

. the May 7 Order -- the public health and safety took second place to expeditious restart.

These reckless accusations that the Commission ignored its statutory responsibilities are not supported by the record.

Given these apparently long-held beliefs, it is difficult to understand why the California Energy Commission took no action to ' challenge the Commission's Order, why CEC did not even request this hearing (which was instituted by private parties),

or why CEC declined to take a position on the issues throughout the course of the hearing.

It is not this Board's role, however, to pass judgment on the process by which the Commis-sion formulated its decisions, nor do we consider it necessary to do so.

Our mandate is to determine whether the modifica-tions at Rancho Seco are sufficient to provide reasonable assurance that the facility will respond safely to feedwater transients.

The adequacy of the modifications can be estab-lished without examining, as CEC inappropriately suggests, the motives of the parties in proposing them, or the circumstances leading to their selection.

8.

The Board also observes a fundamental inconsis-tency in CEC's criticism of the quality of the Commission's decisionmaking which led to the May 7 Order.

While CEC describes this process as hasty and not based upon careful 2

analysis,-CEC uses repeatedly, as the almost exclusive benchmark for its proposed initial decision, the "NRR Status Report on Feedwater Transients in B&W Plants," dated April 25,.

1979 (CEC Ex. 26), which CEC states was the basis for the Commission's Order of May 7, 1979.

See CEC PF 10.

If this report reflects the hasty and -inadequate analysis described by CEC, then there is no-reason why the Board should perpetuate purported. error and rely heavily upon a report issued less than one month af ter the TMI-2 accident and which was not sponsored here by a witness, when we now have the benefit in this record of Staff testimony reflecting an additional year of study of that accident.

III.

PROPOSED FINDINGS OF FACT l

A.

Integrated Control System 9.

CEC's proposed findings on Board Question EC-16 begin with an historical listing of the Staff's concerns that led to the requirement to perform a failure mode and effects analysis ("FMEA") of the Rancho Seco ICS.3 CEC PF 44-50.

.These concerns were expressed by the Staff, shortly after the TMI-2 accident, in the "NRR Status Report on Feedwater Transients in B&W Plants", issued on April 25, 1979 (CEC. Ex.

3 CEC's proposed findings portray Licensee as resisting the FMEA requirement because.it might delay the restart of the

' Rancho Seco facility, and would have the Board' hold that it was improper of Lthe Commission and the Staff to allow the FMEA to become a long-term item. ' CEC PF 50, 61.

Staff witnesses

. testified, however, 'that performance of.the M4EA was always regarded < as a long-term item.

Tr. 1381-1383-(Thatcher, Capra).

In.any case, the ICS reliability analysis was completed within four months of being ordered. O

26).

CEC's proposed _ findings quote.these concerns, yet fail to note that' the concerns 'were based on a lack of understanding of the ICS by the. Staff at the time the document was issued, and that they have subsequeatly dissipated.

Tr. 1270-1272 (Thatcher); Tr. 3712-3713 (Capra).

Staff witness Capra summarized the situation aptly:

I think that at the point in time where this statement was made...we probably had not reviewed any operating experience.

A lot of

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our concerns about the integrated control system were based on myth and folklore I think a little bit.

We had not done any review of the integrated control system; we were concerned that it was possibly a contributor to the transients experienced in B&W plants, and it was logical that we wanted to investigate that.

Tr. 3713 (Capra).

Thus, the Staff's concerns prior to com-pletion of the ICS FMEA are of historical interest only and not relevant to the task at hand.4 4

The other source cited in CEC's proposed findings as expressing concerns about the ICS is CEC Ex.

5, which is a Staff report entitled " Primary System Perturbatio'ns Induced by Once Through Steam Generator".

CEC PF 48 quotes from the first paragraph of Section IV of CEC Ex.

5, which reads: "... review of ' operating experience suggests that ' the ICS of ten is a contributor to feedwater transients.

In some cases the ICS appeared inadequate to provide sufficient plant control and stability. " - CEC PF 48 also refers to Section II of CEC Ex. 5, which states that "in many cases the main feedwater control system does not react-quickly enough or is not sufficiently stable'to meet feedwater requirements.

Rather, the system will often oscillate from underfeed ~ to overfeed conditions, causing a reactor - trip and sometimes a high ' pressure injection initiation."

CEC Ex. 5 was discussed by several witnesses at the hearing.

Cne of its - authors,- Staff witness Rubin, explained that the concerns raised in that document "were preliminary in nature."

Tr. 1187-1188 (Rubin).

While CEC Ex'. 5 was issued after the

. (continued next page) j 4 '

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10.

One historical concern, however, deserves brief mention.

CEC proposed findings 47, 56 and 59 suggest that an ICS malfunction at Rancho Seco could cause simultaneous loss of

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main and auxiliary feedwater.

Whether such an event is theoretically possible at the present time is not revealed by the record; however, as a practical matter, even if an ICS malfunction took place that resulted in such a simultaneous loss, the operators would take manual control of AFW flow (as directed by the Rancho Seco emergency procedures) so that a loss of all feedwater, if experienced, would be short lived.

See Licensee PF 43, 140.

In the near future, of course, the AFW system will be upgraded to safety grade and completely divorced from the ICS.

See Licensee PF 44, 61, 156.

11.

CEC's proposed findings 53 to 56 enumerate Oak Ridge National Laboratory's ("CRNL") reservations about the (continued)

ICS reliability analysis was prepared, the Staff was still reviewing the reliability analysis, and had not received Oak Ridge National Laboratory's evaluation of it.

Contrary to the concern expressed in Section IV of CEC Ex.

5, the operating experience shows that the ICS is not a contributor to feedwater transients and is in fact instrumental in offsetting their effects.

Tr. 713-714 (Karrasch).

Also, Staff witnesses explained that' the main feedwater oscillation referred to in Section'II of CEC Ex. 5 was not caused by any problem with the ICS but by improper action by the operator in

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transferring control from automatic to manual modes.

Tr. 1308 (Capra); see generally, Tr.:1306-1312-(Thatcher, Capra, Rubin).

Thus, the concerns expressed in CEC Ex. 5 are again based in the Staff's misunderstanding of the ICS prior to analysis of the B&W reliability study, 'and, like those expressed in CEC Ex.

26, dissipated when;more information about the system became available. -

adequacy.of the~ ICS FMEA.

These~ criticisms were answered at the' hearing and are fully addressed in Licensee's proposed findings 53-57.

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34.

CEC has. questioned ~ whether Rancho Seco and all other PWRs are in compliance with 10 C.F.R. S 50.46.

CEC PF 138-145.

The actual evidence in the record, however, is undisputed in support of Licensee's compliance with the ECCS acceptance criteria.

See Licensee PF 114; Staff PF 79, 80.

Consequently, there is no basis for CEC proposel conclusion of law 5(e).

As the record makes clear, the additional small-break LOCA analyses performed in response to the Commission's Order of:May 7, 1979, were directed toward the development of realistic operator guidelines and were not meant to be an Appendix K (to 10 C.F.R. Part 50) demonstration.

See Tr. 1036, 1037 (Jones).

E.

Auxiliary Feedwater System Reliability 35.

An important element of the Comn ission Order of May 7, 1979, was its emphasis on improving the ;imeliness and reliability of the delivery of auxiliary feedwater at Rancho Seco.- All witnecses at the hearing who gave testimony on this subject agreed that accomplishment of the nine short-term AFW system action items included in the Order contr'buted to a faster and more reliable delivery of AFW to the steam generators.

See, Tr. 1559, 1570-1572 (Matthet s); Tr. 2077,

'2078 (Dieterich); Tr. 3255-

.'_5 7 (Rod rigue z) ; Mat'. hews AFW Testimony at 14, 15; Dieterich Testimony at 10; St.:f Evaluation at 12; and see, Licensee PF 136-148; Staff PF 116-118, 124.

Surprisingly, CEC's proposed findings 69 and -,,

81(a) would have the Board express the opinion that the nine short-term modifications did not materially upgrade the timeliness and reliability of the AFW system at Rancho Seco.'

The -Board cannot agree with such a proposed finding, for not only is it without any support in the record, but it is based on questionable reasoning.

36.

CEC proposed finding 69 would deny significance to six of. the nine short-term itens because they were proce-dural in nature and referred to ' actions that the Rancho Seco t

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operators already knew how to perform.

However, Staff and f

Licensee witnesses explained at length why these procedural changes were useful and improved the AFW timeliness.

See, Licensee PF 137-141, 144, 1-148; Staff PF 117, 118.

9 CEC PF 66-68 and 70 crit::ize the process of selection cf the items included as short-.erm modifications in the AFW area i

and allege that they were arrived upon without analysis and solely on the basis of expediency, as items which ceald be completed in a short period of time so as to " ensure rapid restart of the facility."

As noted earlier, it is not for this Board to investigate the moti

.s of the parties in proposing or adopting the ~ actions at issue here.

Moreover, 5ne note that all the testimony ' indicates that 'the short-term actions were chosen because "they.were those that were more directly related to the safety of the plant."

Tr. 2077 (Dieterich).

Bo th Staff and Licensee witnesses expressly denied that the time in which the measures could be imple aented was a factor in whether they were included =r short-terr items.

Tr. 1571 (Ma tthews ) ; Tr.

3261~ (Rodrig de z).

10 It' is puzzling that CIC w. uld find little value in the institution of written proceduro' to instruct the Rancho Seco operators on the proper actions to take to ensure AFW flow, since CEC would have the Board require new and revised plant procedures, ostensibly as an - improvement to safe plant operation.

Comcare CEC I? 69 with CEC CL 5(d), 5(f), 5(g),

5(n), 5(o).

37.

The remaining three items (Nos. 5, 7 and 8),

which pertain to additional instrumentation to veri *y in the control room that AFW flow has baen provided, are dismissed by CEO on the ' grounds that operators "already had methods to verify the proper functioning of the AFW system."

CEC PF 69.

Again, all witnesses testified that this additional instru-mentation increased the timeliness and reliability of the AFW system by providing better indication to the operators of whether AFW had been initiated and whether it was functioning properly.

See Licensee PF 142, 143, 145, 146, 148; Staff PF 117, 118.11 We reject, therefore, CEC proposed findings 69 and 81(a) as unsupported by the record.

38.

CEC proposed findings 70 and 81(a) criticize the Commissit : Order of May 7,1979, for not requiring the com-pletion <2 an AFW reliability study prior to the restart of the facilitv However, Staff and Licensee witnesses concurred that the short-term actions were sufficient to upgrade the AFW system at Rancho Seco.

Tr. 1570, 1571 (Matthews); Tr. 2078 (Dieterich).

That the criticism leveled by CEC is not valid is evidenced by the results of the reliability study, which indeed 11 CEC s position with respect to additional instrumen-tation.o verify AFW flow is, to say the least, inconsistent with its proposed findings in the instrumentation area, where it would h ve the Board require installation of core level indicators, wide range pressurizer indicators and natural cir-culation flow meters, even though these items are r.ot even available and would provide only backup to information that the o;erators already possess.

Compare CEC PF 69 with CEC PF 2?'-231.

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identified only minor equipment and procedural changes as needed to make-the AFW system even more reliable.

Tr. 1571, 1618-1619 (Matthews).

39.

CEC would find the AFW reliability study incomplete because it-did not utilize avoidance of steam

-generator boil dry as a success criterion; on the basis of this alleged shortcoming, CEC would have the study redone after the AFW system is upgraded to safety grade.- CEC PF 72, 73, 81(b).

We see no need for such action.

While Licensee and the Staff have different views on what is the proper criterion for mission success for the AFW system, the reliability analysis included one case (operator reaction within 5 minutes) that would be roughly equivalent to a steam generator dryout avoidance criterion.

Licensee PF 153, Staff PF 120.

There-fore, if the Staff is right in its position (a question we need not resolve, see Staff PF 122), the AFW reliability analysis results for the 5-minute case can be used to determine the

-comparative reliability of Rancho Seco vis-a-vis Westinghouse

("W") plants,12 without having to repeat the study.13 Tr.

1607-1610, 1657-1665 (Matthews).

40.

Another set of CEC proposed findings (74-76, and 81(c)) would' require Licensee to verify. and revise, as neces-sary, its procedures for-AFW operation in' the event of a loss of all AC power.

This matter is raised only because the Staff has requested, as a further improvement in AFW reliability, 12 The AFW reliability study shows that the Rancho Seco AFW has comparable reliability to W plants for the 5-minute case, a result that will not change if the mission success criterion is redefined.

Licensee PF 153; Staff PF 121, 122.

CEC misconstrues the record when it says, in its PF 78, that if the AFW success criterion were revised -to be no boil dry of the OTSG, the Rancho Seco results would tend to show less reliability in comparison to W PWRs.

None of the record citations offered ("Tr.1608, 1660-61 (Matthews); 1490 (Novak)") supports such a finding.

In fact, at Tr. 1660-61 the following exchange is recorded:

MR. SHON:

I think we established this morning...

that...(Mr. Matthews] didn' t think that the comparison between Westinghouse reactors and SMUD offered by this diagram would change very substantially if the criterion used in the calculation for SMUD were the steam generator should not boil dry.

Tha t's wha t I understood you to say this morning.

MR. MATTHEWS:

Ye s, and I believe that to be true.

Let me just say two other things to try and clarify this.

Number one, if the--if ~ we used only boil dry as the sole criteria of success of the AFW system, and that boil dry time were decreased, then I think insofar as the SMUD chart, it would have the tendency to move the triangle to the lef t.

It would go in that direction,. whereas it

- would not do that on the case of Westinghouse studies simply because the five minutes is considerably shorter than the boil-dry time for the Westinghouse plants.

(Emphasis added).

13 No claim has been made that the data or methodology employed in the AFW reliability study were improper.

1 -

.l that Licensee station an operator at the_ flow control valves following a loss of all AC power, and that adequate lighting and communication with the control room, independent of AC power, be provided for two hours at that location.

CEC Ex. 21, at 8.14 41.

Licensee has disagreed with this Staff position Tr. 2355 (Dieterich).

Licensee observes that loss of all AC power is outside the design basis of the plant.

Tr. 2374 (Dieterich).

Licensee also points out that loss of all AC power is an extremely unlikely event, since off-site power to Rancho Seco is provided by five separate 220 kV transmission lines on two different routes, so that no single failure can lead to loss of all off-site power.

Tr. 2376, 2386 (Dieterich).

Rancho Seco has never experienced a loss of off-site power since commercial operations began in 1975.

Tr.

2377 (Dieterich).

Additional sources of AC power are provided by two independent, on-site diesel generators which are tested periodically to verify their operability.

Only one failure of one of those diesel generators during testing has been experi-enced so far.

Tr. 2376, 2377 (Dieterich).

42.

A complete loss of all AC power requires, therefore, the simultaneous occurrence of three events:

loss of all off-site power (in itself requiring a multiple failure) 14 _The same item would ~ require Licensee to make long term plant modifications so that AFW system operation and steam generator level control can be maintained from the control room for two hours upon a loss of all AC power.

CEC Ex. 21, Enclosure 1 at 8..

and loss of both~ diesel generators.

Staff witness Matthews testified that this multiple failure event has a very low 3

probability.

Tr. 1498 (Matthews).

We do not attempt to resolve the dispute between the Staff and Licen.ee, which is i

unrelated to the May 7,1979 Order or the AFW reliability analysis.

Instead we note that, in view of the low probability of-a loss of all AC power, no significant reduction in the reliability of the Rancho Seco AFW system will result while the Staff and Licensee work out their differences.

43.

Finally, CEC would have us order that the Rancho Seco AFW system be upgraded until it is more ' reliable than those at 1[ PWRs.

CEC PF 77, 81(b).

We emphatically rej ect such a requirement.

All parties agree that the Rancho Seco AFW system should be " extremely reliable."

Tr. 1489, 1490 (Novak);

Tr. 2093 (Dieterich).

The Staff, however, has set no quantita-tive goals to differentiate B&W plants from those of other man-ufacturers in ~ terms of reliability.

Tr. 1487, 1488 (Matthews).

This is not a race among licensees, and we doubt that our imposing such a standard would be meaningful or even lawful.

44.-

In its present condition, the Rancho Seco AFW system meets the AFW system acceptance criteria contained in 1

-the NRC Standard Review Plan, Section 10. 4. 9.

Matthews AFW Testimony at 4-6.. All witnesses, including CEC witness Lewis, agreed that the Ranco Seco AFW system is very reliable, never having failed when called ' upon to deliver auxiliary feedwater.

3 Lewis Testimony at 3,.4;-Tr. 3255 (Rod rigue z) ; Tr. 1522 i l l

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(Capra);. Rodriguez Testimony.at 49.15 Moreover,- the Rancho Seco AFW system will soon be upgraded to. safety grade stand-ards, rendering it." extremely-reliable", as the Staf f defines the. term.

Staff Ex. 4 at 5-41; Tr. 2095 (Dieterich).

Beyond that, additional long-term modifications will be undertaken to improve its reliability even further.

Licensee PF 156; Staff PF 124,.125.

Quite frankly, we fail to understand CEC's rationale for seeking to study the system again or having its reliabil,ity-measured against that-of W cr any other plants.

We reject the actions proposed in CEC proposed finding 81.

F.

Safety System Challenges 45.

In its proposed finding.90, CEC asserts that neither Licensee's direct testimony nor its proposed decision addresses-the concern set forth in Issue CEC 1-1, which CEC recasts as follows :- that the frequency of high pressure i

injection system operation at Rancho Seco is in excess of that assumed during titi design and licensing of the facility.

Licensee's witnesses did testify that the expected increase in the number of reactor trips as a result of the modifications at Rancho Seco is not anticipated to require an increase in the 25 The " failure" alluded to by CEC in its PF 79 (boil dry of one 13r both 0TSG) during the 1978 " light-bulb" incident at Rancho. Seco was not caused by a failure of the AFW system, but by a. non-nuclear instrumentation failure that delayed AFW initiation.

CEC Ex. 45, attachment at 2.

The AFW system did

. operate during the incident and maintained flow to at least one OTSG through the transient.

Staff Ex. 4 at 5-56, 5-57;-Tr.

3308-3310 (Rodriguez)..

actuation frequency of high pressure injection.

Karrasch-Jones Testimony at 41; Tr. 997 (Karrasch).

Licensee's witness also testified that high pressure injection is among the events for which specific data are recorded' and monitored to assure that challenges to safety systems do not exceed their design and licensing basis.

Rodrigaez Testimony at 50, 51; Licensee PF 161.

Thus, the question posed in Issue CEC 1-1 (which addresses the total number of challenges), though not the version written into CEC's proposed findings (which addresses the frequency of actuation), was answered by Licensee.

46.

CEC proposed findings 92-94 rely almost exclusively on the survey of reactor trip data through September,1979, reported in Table 4.1 of Staff Exhibit 4.

Yet, the Staff advises as follows on the use of the survey results:

The difficulties in accepting these trip frequencies as valid inferences of the effects of revised setpoints are discussed in Sections 4. 4. 2 and 4.4. 3 of this report.

Thus, the reader is cautioned against using the reactor trip frequencies presented in Table 4.1 as predictors of future performance.

Staff Ex. 4 at 4-12.

47.

In proposed finding 96, CEC would have the Board make a number of factual statements on the effects of the revised - setpoints for the PORV and high pressure reactor trip, without a single citatior to the evidentiary record.

We cannot adopt such proposed findings, which are not a mere summary of previously presented findings.

See 10 C.F.R. S 2.754(c)

(proposed _ findings of fact shall include exact citatlans to the I.

L e-transcript of record and exhibits in support of each proposed finding).

48.

In CEC proposed finding 97, we are presented with a vivid _ example.of the casualness with which CEC would have this Board modify the ~ Commission's Order of May 7, 1979.

Observing -- (1) that it appears possible to increase the reliability of the PORV by making the PORV and related systems safety grade; (2) that a proposal for such a PORV fix has been made by Consumers Power but not acted upon by the NRC; and (3 )

that there is no reason Rancho Seco could not implement such a fix -- CEC proposes that we order Licensee to make the PORV safety-grade.- CEC PF 97.

Yet, we have no testimony before us recommending su 4 a change, no evidence indicating that such a change is necessary to provide reasonable assurance that the facility will respond safely to feedwater transients, no evaluation of the feasibility of such a change, and no inte-grated systems analysis of the effects of the change on plant operation.

We cannot redesign reactors with such a haphazard,

"why not" approach and do justice to the NRC's responsibility

.to protect the health and safety of the public.

It is for this reason that the Staff is first studying the Consumers Power proposal.

Staff Ex. 4 at 5-29.

Accordingly, we reject CEC proposed finding 97.

l 49.

CEC proposed findings98-102 on the number of challenges to the.high pressure injection system ignore i

Licensee's testimony that operating procedures at Rancho Seco

have been changed to avoid adding thermal cycles to the HPI nozzles.

See Tr. 3358-3359, 3409-3410 (Rod rigue z).

G.

Operator and Management Competence

50.. CEC-begins its - proposed initial decision on operator land management competence issues with the observation that since B&W plant sensitivities have not been reduced by design changes, Licensee must substantially upgrade plant operator education, training and experience, again citing the Apr il, 1979, Staf f r epo r t ( CEC Ex. 26).

CEC PF 153.

CEC's earlier proposed findings, however, do not focus principally on whether B&W plant sensitivities have been reduced, but rather on whether they have been eliminated.

See CEC PF 27, 31, 41,

43.

The only CEC propose'd finding which asserts a failure to reduce sensitivities (CEC PF 37) has been rejected as unsup-ported by the substantial evidence.

See paragraph 22,, supra, a

Consequently, the Board does not accept the premise which underlies CEC's proposed findings on this issue.

51.

CEC proposed finding 154 asserts that the additional training directed by the Commission's Order of May 7, 1979, is the only additional operator training experience

~

leic] instituted at Rancho Seco since the TMI accident.

This is not true -and the statement is directly contradicted by the testimonyL of Mr. Rodriguez and Mr. Wilson which is cited by CEC.

The-May 7 Order required specific TMI-2 training on the B&W. simulator, whereas the witnesses described additional l !

lecture and informal discussion training by the Rancho Seco Operations Supervisor, Training Supervisor and Shif t Super-visors, formal training by General Physics Corporation, and the (non-simulator) testing of operators.

See Rodriguez Testimony i

at 15-1" and Appendix III; Wilson Operator Testimony at 4-7.

See also, Licensee PF 171; Staff PF 143.

In addition, the record shows that Licensee has modified its requalification training program to include the TMI lessons learned.

Licensee PF 169;.. aff PF 138.

None of these training efforts, other than the special simulator training, were required by the Commission's May 7 Order.

52.

CEC denigrates Licensee's special post-TMI training of operators because the training consumed only 27 hours3.125e-4 days 0.0075 hours 4.464286e-5 weeks 1.02735e-5 months .

CEC PF 155, 157.

In fact, that figure does not include Shift Supervisor training of operating crews on plant modifica-tions and procedure changes, including a plant walk-through to assure familiarity with. the location of active components in the auxiliary feedwater system.

Rodriguez Testimony at 17 and Appendix III.

In any case, as CEC's witness pointed out, the number of hours involved should not be the sole basis for assessing the adequacy of training, and we decline to hold that 27 hours3.125e-4 days 0.0075 hours 4.464286e-5 weeks 1.02735e-5 months or any other number of hours represent inheren tly insufficient training.

See Tr. 3610, 3611 (Bridenbaugh).

53.

In the testimony of Mr. Rodriguez (Tr. 3088) cited in CEC proposed finding 158, the witness is discussing only the requalification training program.

Changes to the " hot..

j license" training program, however, are described in the

record.

Tr. 3075 (Rod riguez).

54.

Contrary to CEC proposed finding 161, Staff witness Wilson did not testify that Licensee's (presumably l

current) operator training program is similar in scope, amount, and type of training to_ general industry practice.

Rather, he testified that there were no substantial differences.

Tr. 3810 (Wilson).

Later he compared the SMUD and TMI training programs prior to the TMI-2 accident, and testified that while he assumed they were fairly similar, he had not made a detailed comparison.

Tr. 3811, 3812 (Wilson).

55.

CEC f aults Licensee for not offering persuasive evidence to support a finding that the Rancho Seco training program is qualitatively better than that of other utilities.

CEC PF 162.

CEC assumes a standard, however, which is patently 4

inappropriate and unsupported.

There is no requirement that Licensee prove superiority to other utilities.

Rather, our mandate is to determine whether there is reasonable assurance that the facility will respond safely to feedwater transients.

That inquiry is not advanced one wit by considering CEC's proposed standard (which, of course, Licensee could not meet wit.iout pr- ;enting evidence on a multitude of other utility training programs).

Accordingly, the Board will concentrate on Rancho Seco -- which we believe is our charter from the Commis-sion.

1 _

,,e

56. 'For the; reasons set forth_in_ Staff _ proposed finding '141, _the Board does not adopt CEC proposed findings 163-168 on operatorn training at' the B&W simulator.

57. ' CEC would have the Board find, based upon its review of-the three ~ operator depositions in the record, that we are unpersuaded that their training is superior, or - that they are more competent than operators at other facilities.

CEC PF 173.

See also, Tr.

3904.(Wilson) (if the total number of LERs is comparatively low, there 1s no basis for concern if the ratio of personnel-caused LERs is comparatively high).

62.

CEC also ignores the evidence in its proposed j

findings 194 and 195.

The Staff witnesses flatly rejec*.ed CEC 's suggestion of significance in the increased number of LERs, and testified that they would look for safety-related patterns, and not at the total numbers of reports.

Tr. 4075 (Canter); Tr. 4091 (Johnson).

63.

In proposed finding 198, CEC accuses Licensee's Manager of Nuclear Operations of having "no idea" how operators were performing on the requalification exams.

What Mr.

2 Rodriguez actually testified, however, is that he could not recall.the specific grades.

Tr. 3084-3086 f, Rod rig ue z).

64.

Rejecting all other evidence and relying exclusively on the testimony of the Performance Appraisal Branch witnesses (CEC PE 185-190), CEC proposes to conclude our i

--v

findings on this issue with the coservation that SMUD's management controls are-poor in comparison to other utilities.

CEC PF 199.

The Board is more interested, however, in whether Rancho Seco's management is competent to respond to feedwater transients.

There is no negative testimony on this question, while there is an abundance of affirmative evidence.

See Licensee PF 195-203; Staff PF 170-180.

Accordingly, we decline to modify the Commission's Order, as suggested by CEC, to impose conditions which have not even been identified.

See CEC CL 5(k).

65.

The Board finds little significance in the so-called admission by Licensee that it is possible for unlicensed operators to be called upon to perfo:m an operation for which they had never been trained and which they had never per fo rmed.

See CEC PF 205 and 208.

CEC failed to cite Mr.

- Rodriguez's testimony, however, that unlicensed operators normally are instructed in the performance of an operation befor e they are called upon to do it, and that their training would assist them even if ar. unexpected event were to occur.

Tr. 3437, 3438 (Rod rigue z).

66.

In their proposed findings 206 ati 207, CEC suggests that we discuss the allegations which led to an NRC inspection at Rancho Seco in 1979 on the questions of turnover in unlicensed operators and the adequacy of their training, without proposing that we then discuss the findings of the investigation.

The - inspecto rs found :

no items of

- 3 5-

. noncompliance or~ deviation; that while the turnover of unli-censed operators was high there were no regulatory requirements or specific safety concerns related to this fact; that the training of new personnel was not minimal as alleged; that all operators appeared competent; that experienced people were available to provide help to inexperienced personnel if needed; and that while it is possible that improvements could be made, Licensee's training appeared adequate from a regulatory standpoint.

CEC Ex. 39 at Summary and 4.

67.

Issue CEC 3-3 questions whether NRC and SMUD l

adequately ensure that emergency instructions are understood by and are available to plant personnel in a manner that allows quick and effective implemen.ation in an emergency.

CEC would now create a new issue after the hearing is concluded.

In its proposed findings 209-211, CEC suggests a Board inquiry into the format and the content o one Rancho Seco emergency procedure, rather than on operator understanding of the procedure and its availability.

Beyond the fact that the issue is not before us, no witness testified that the procedures are 1

inadequate or in need of revision.

The record shows that

-licensed operators understand the emergency procedures.

See Staff PF 160.

We decline, ;han, to order the wholesale revision of Licensee's emergency procedures suggested by CEC.

See CEC CL 5(o)..

H.

Instr umentation 68.

CEC witness Minor testified that the ability to quickly diagnose the Rancho Seco plant would be enhanced by the addition of core-water level indication and a natural circula-tion meter.

Minor-Bridenbaugh Testimor..y at 17.

Mr. Minor's testimony was c ontradicted,' however, by several witnesses, including Dr. Lewis on behalf of CEC.18 Licensee PF 211-213; Staff.PF 189-193.

No witness testified that additional instrumentation at Rancho Seco is necessary to provide reason-able assurance that the plant will respond safely to feedwater transients.

Consequently, we do not adopt CEC proposed findings of fact 225-231 and conclusion of law 5(p).

I.

Hydrogen Control

[

69.

The proposed findings submitted by the parties evidence agreement on most of the facts relevant to Board Question H-20.

CEC proposed finding 253, however, would have the Licensing Board find that Rancho Seco does not have a readily available hydrogen recombiner.

The undisputed evidence 18 CEC proposed finding 126 cites the testimony of Dr. Lewis for the proposition. that the feed and bleed cooling mode he envisioned. could be used only if one has core coolant level l indication.

Dr. Lewis, however, was describing a cooling mode in which there was -intermittent operation of high pressure injection.

See Lewis Testimony at 12.

Licensee 1

and Staff witnesses, on the other hand, referred to " feed and bleed" cooling as a mode with continuous HPI operation.

See Tr. 955, 956 (Jones); Tr. 1355 (Norian).

There is no evidence that vessel level indication is required for this cooling mode.

Se-Tr. 872-874 (Jones). - -

'.i shows the opposite.

Rancho seco could-have a recombiner delivered on loan ' to the site upon a day's notice.

Licensee PP 231; Staff PF 207.

While no procedures currently exist for its use, installation of the recombiner would be a simple matter.

Id.

The recombiner would be available early enough in the accident to assist in reducing the hydrogen concentration in containment.

Jd.

d 70.

CEC postulates an accident more severe than a five percent fuel failure, yet not as severe as the accident at TMI-2, and theorizes that a recombiner "would possibly permit early enough utilization to keep hydrogen concentrations below the 4 percent flammable level."

CEC PF 249.

There was no 6estimony, however, identifying the accident sequences (if any) that would fall.into the category postulated by CEC, nor any indication that the use of a recombiner would provide success-ful mitigation of those accident sequences and that a purge system would not.19 In the absence of any record support for CEC 's conjecture, the Board cannot order Licensee to " install l

one or more hydrogen recombiner systems" at Rancho Seco,

i particularly since the system currently availabl? meets all NRC requirements and Licensee has already made arrangements to obtain on loan the same equipment whose compulsory installation is sought.

We will leave such a directive, if appropriate, to be issued upon completion of the NRC generic rulemaking.

19 The proposed NRC rulemaking proceeding on hydrogen management would be the logical forum for identifying any accident sequences for -which a ~recombiner would provide protection ~notfavailable from a purge system. _

i

J.

Controlled ' Filtered Venting 71.

All parties filed extensive and detailed

. proposed. finding s - on CEC Issue 5-2.

See Licensee PF 247-290, Staff PF 222-249, and CEC PF 266-326.

The breadth and tech-nical detail of-the findings suggest that this is not an issue amenable to simple answers and indicate that, as Licensee and the Staff suggest, the proper place for resolving the many open questions left in the record regarding controlled filtered venting system ("CFVS") feasibility is the rulemaking pro-ceeding soon to be instituted by the NRC.

Licensee PF 290, Staff PF 249.

72.

The Rancho Seco containment building meets the General. Design Criteria set forth in Appendix A to 10 C.F.R. Part 50, and is, therefore, safe to operate.

Licensee PF 248; Staff PF 234.

The Rancho Seco containment can remain leak-tight through a design basis accident ("DBA"), which is a severe LOCA generating prescures of 52 psig.

Licensee PF 254; i'

Staff PF 230.

The Rancho Seco containment is designed to withstand ' a pressure of 59 psig under earthquake and wind loading conditions, has been tested successfully at 69 psig, and may very well be able to withstand pressures of 120 psig or 1

more.

Licensee PF 255-256; Staff PF 230-233.

The pressure at i

which the Rancho Seco containment would fail is unknown, and is probably not'a single pressure but a band of pressures depending on the accident sequence.

Licensee PF 257; Staff PF 230-232.

4 -

73.

Since the Rancho Seco containment satisfies the General Design Criteria and can probably withstand pressures greatly in excess of those resulting from the DBA, a fundamen-tal question about the feasibility of a CFVS is whether implementing such a system at Rancho Seco might degrade the integrity of the containment to the point of violating the Commission's General Design Criteria.

CEC proposed findings 271-273 attempt to prove that a CFVS would not violate the General Design Criteria because such a system could be made to activate at pressures beyond those generated in the DBA.

This could be accomplished, in CEC 's view, by. designing the systems' interface with the containment, the so-called " rupture disc,"

to withstand pressures above the containment design pressure.

Rup.ture discs, however, can malfunction and fail at pressures below the containment design basis, in which case the General Design Criteria would be violated.

Tr. 2232 (Dieterich). 20 74.

In addition, it may prove necessary to set the disc rupture pressure below 59 psig in order to accommodate the transient produced during certain overpressurization sequences.

Scaff witness Meyer testified that such a possibility has already been identified by the Staff in the Indian Point and Zion studies:

One of the problems, at least with the Zion and Indian Point study, that is complicating 20 Placing several identical discs in series to protect against premature-disc -rupture would not necessarily solve the problem because of the possibility of a common mode failure.

Tr. 2383, 2384 (Dieterich). __

considerably the question is that for some of the accident sequences that we are con-4 sidering,'there is a large_ pressure spike

.that comes along; with the molten core coming in contact with the accumulative water.

This pressure spike has been estimated to rise up to about 120 psig.

It is a considerable complication because the spike rises so rapidly that the penetrations to the contain-

. ment would have-te be very, very large in order to accommodate that if you have a high pressure point, high pressure set point for activation of the system.

Therefo re, one of the considerations is to lower tha t set point considerably in anticipation of that pressure spike occuring later in the accident i.

sequence.

If, for example, you would have that type of accident sequence with a very high pressure set point, let's say, 85, 90 psi, then it probably -- that system probably would not be

-able to -accommodate that particular accident.

Tr. 2028-2829 (Meyer) (emphasis added).

75. If a rapid trar.sient such as that described by Mr. 'Meyer were part of a dominant overpressurization sequence, an effective CFVS might by necessity have to violate the

~ General Design Criteria in order to halt the transient before it led to containment failure.

Tr. 2232-2235 (Dieterich).

76.

In view of these very realistic and yet unad-dressed problems, the Board is unable to conclude on the basis of the' record before us that a.cSTE can be designed so that it 7

does not violate the NRC 's General-Design Criteria.

77..

Assuming, nevertheless, that a CFVS can be designedeso that it satisfies the NRC's General Design Criteria, it would not be practical to implement such a system

-unless there was a significant risk against which the CFVS.

could provide protection beyond that currently available at Rancho Seco.21 CEC.PF 279.

In order to identify such risk, one must define the accident requence creating it, estimate the accident's probability of occurrence, and assess its public' health and economic consequences.

All these matters were debated at the hearing, and substantial questions were lef t unresolved as to each of them.

78.

Of all possible modes of containment failure, an effective CFV3 would only provide mitigation of 'those accident sequences in which the containment fails from over-pressuri;.--

tion, that is, the PWR-2 and PWR-3 release categories in the Reactor Safety Study.

Licensee PF 252; Staff PF 228; CEC PF 287.

It is, however, far from clear that a PWR-2 or PWR-3 accident sequence would be the dominant failure mode at Rancho Seco.

It Js possible that a FWR-1 accident sequence (rupture of containment by steam-explosion generated missiles) may be the dominant mode of containment failure, in which case the analytic and economic resources of the NRC and the utilities should be directed at mitigating that form of containment failure.

Licensee PF 261, 262.

21 CEC's proposed findings incorrectly characterize the safety systems for overpressurization protection at Rancho Seco as designed to withstand only "a single design basis accident which is less severe than many postulated accident sequences."

CEC PF 281; see also, CEC PF 279, 280.

Actually, the containment building and the other overpressurization protection systems at Rancho Seco can accommodate all accident sequences within the envelope of the DBA, as well as a good number of accidents producing pressures and temperatures beyond those in the DBA.

Licensee PF 255-257; Staff PF 231, 232.

l 79.

Even if the PWR-2 and PWR-3 release categories constitute the dcminant containment failure modes at Rancho Seco, the record does not indicate that the public risk -posed l

by such. accidents is significant.

In this context, risk is 1

defined.tur probability of accident occurrence times accident

-consequences.

Accidents leading to PWR-2 or. PWR-3 types of containment failure are very improbable.

Licensee PF 263; Staff PF 246.

Therefore, the consequences of such an accident would have to be shown to be very severe. in order for the public risk to be anything but negligible.

No such showing was made.

80.

The basis for CEC's estimates of the conse-quences of a PWR-2 or PWR-3 containment failure mode is a study entitled " Analysis of Public Consequences From Postulated Severe Accident Sequences In - Underground Nuclear Power Plants" prepared by a CEC consultant, and received in evidence as SMUD Exhibit 18.22 The assumptions utilized in SMUD Exhibit 18 are discussed in detail in Licensee's proposed findings 265-269.

Two additional points must be made. in response to CEC's proposed findings.

First, it takes no independent analysis to conclude that the health and economic consequences from an 22 The main report produced by CEC as part of its study of underground siting. of nuclear power plants was entitled

" Underground Siting of Nuclear Power. Reactors:

An Option For Califo rnia," ("the Underground Siting Study"), received in -

evidence as SMUD Ex.11.

The-analysis contained in SMUD Ex. 11 was to ' a large-extent, if not entirely, prepared by contractors.

SMUD ' Ex. 11 at 7-2.,

uncontrolled release given in Mr. Nix's testimony are grossly inflated because they are based on extreme assumptions.23 Those assumptions are well ~ identified in SMUD Exhibit 18, where many of the results appear in parametic form so that the effect of' different assumptions can be ascertained.

CEC chose the combination of assumptions that produced the most severe health 24 consequences and thus produced a totally unrealistic sce-nacio.25' 23 CEC attempts to discredit Licensee's proposed findings l

with respect to the consequences of a PWR-2 accident on the basis that Licensee has never conducted independent studies of

~

the matter.

CEC PF 293.

For that matter, neither have CEC witnesses.

The study was performed by a consultant, who frankly acknowledged that its mandate was to provide upper bounds to all relevant parameters so as to cause the most severe consequences, and to perform "[clalculations of public health' consequences... based on enveloping considerations for those accident sequences."

SMUD Ex. 18 at 5.

24 CEC PF 294, n.46 claims, on the basis of a statement at

p. 7-5 of SMUD Ex.11, that a four-hour evacuation time was used to compute the consequences of a PWR-2 accident.

The statement in SMUD Ibc. 11 is erroneous.

The contractor that performed the analysis clearly indicated in its report that "[t]he summarized results for the surface plant...are for the 24-hour emergency evacuation case, although fewer early health effects were computed for other. effective emergency evacuation criteria."

l SMUD Ex. 18 at V-36.

l 1

25 CEC PF 294 defends the results presented in Tables 2 and 3 of Mr. Nix's testimony-by stating. that "rather than assuming specific variables, it analyzed the range of consequences resulting from a broad spectrum of critical assumptions."

Such is not the case.

The results are given as a range of values not because they utilize varying ' assumptions, but because they represent four plant locations in-California.

CEC had 'available the specific results applicable to Rancho Seco, which happened to fall towards the low end of the' range.- We fail to understand why those specific results were-not USed. - _

e 81.

We find, therefore, that. the public health and economic consequences of an uncontrolled overpressurization accident have not been adequately addressed in this proceeding, but are certain' to be far more modest than the estimates offered ' by ' CEC witness Nix.

This finding, combined with the extreme improbability of an overpressurization failure of the Rancho Seco containment, leads the Board to conclude that public risk associated with an overpressurization accident is small enough that no immediate action needs to be taken by Licensee to provide protection against such an accident.26 82.

The second point which needs to be made is that no connection has been established or suggested (except in CEC PF 297 and 325, which are rejected as unwarranted) between i

Rancho Seco's status as a B&W reactor and the probability of containment. failure from overpressurization.

Plants with B&W 1

NSS systems are not more likely to experience containment 1

5 26 According to Licensee PF 269, the risks posed by CEC's estimated consequences of an overpressurization failure of containment at Rancho 'Seco are "not out of line with other risks, both man-made and natural, deemed acceptable by society although not necessarily by all individuals."

CEC PF 293 and 296 upbraid Licensee forEproposing such a - finding, which CEC terms " sanguine acceptance" Dof the risk posed-by an overpressurization accident.

The conclusion cited, however, is not Licensee's, but was reached

. by CEC in 'its Underground Siting Study af ter reviewing the 'same health'and economic 1 consequences estimates presented by CEC here.

See-SMUD Ex. 11 at 7-10.

In SMUD Ex.11, CEC arrived at the con-clusion that the potential of 17 deaths from an overpressurization failure of containment was acceptable "[g]iven the general unlikeliness of the accidents considered in this study." Id.

We agree with this' ' conclusion Ltd observe that it 'is not the relatively modest censequences of such an accident which alone make thr. risk; acceptable, but the combination of those consequences with a i ery-low probability of accident occurrence.

i i

failure from overpressure than those designed by other manufacturers.

Dieterich Containment Testimony at 4.

If anything, the equipment and procedural modifications instituted at Rancho seco in the wake of the TMI-2 accident make it less

1ikely, instead of more, that a feedwater transient at Rancho Seco'will lead to an overpressurization failure of the contain-ment building. 'Dieterich Containment Testimony at 1, 2.

83.

In ' any case, the evidence at the hearing lef t many doubts in the -Board's mind as to whether a CFVS can be

" designed ' correctly and. implemented properly" at the present time.

Licensee's propcred findings 273 to 275 summarize the difficulties in designing a passive CFVS due to the multipli-city of. potential containment failure pressures and the uncertainty of what those _ pressures would be.

CEC character-izes these difficulties as "more apparent than real" and suggests that the solution to the problem is to disregard them.

4 CEC would discount the possibility of unnecessary filter actuation because "the very high effectiveness of the filter would largely mitigate any unnecessary releases."

CEC PF 309.

The do not share CEC's " sanguine acceptance" of the. possibility of unnecessary radioactive releases.

Aside from the fact, further~ discussed below, that the performance of the CFVS is far from established, this Board cannot endorse implemen ta tion of a concept-whose most important parameter (pressure setpoint) has not been. determined, and which if improperly set may lead to Lunnecessary radioactive doses to the public.

.i __

j 84.

Finding. the proper rupture pressure for the discs is,not the only performance problem with CFV5 identified

.at the hearing.

Other problems that came to light ' are dis-cussed in Licensee's proposed - findings 276 to 282 and Staff proposed finding 242.

CEC had no answer to these problems.

In particular, CEC failed to respond to the criticism that the

-attenuation factors 'shown in Table 5 of CEC w'itness Nix's

~

testimony, and computed for an underground nuclear power plant, are ' inapplicable to a surface facility like Rancho Seco.

They were computed on the assumption that the filter discharged into the plant's tfoundation many feet aeneath the surface, a procedure not available at surface fa.ility.

Therefore, the record does not show what attenuatian factors could be achievable with.the CFVS proposed by CEC at a plant such as Rancho Seco, but they most likely would not be-of the same magnitude as. those cited in Mr. Nix 's testimony.

t j

' 8,5.

In addition to performance questions, Licensee and Staff witnesses pointed out some potential problems that may be produced by a - CFVS, such as adverse impacts on other plant safety systems, the possibility of hydrogen ignition due to the system's operation, the possibility that a CFVS might exacerbate a low-consequence accident into a major one, and the potential negative impact' of a concentrated rad ioac tive

.27 CEC dismisses this criticism by leaving it to a site-specific

- study.to determine whether~ it 'is possible to implement a surface filter equivalent :in _ size to the subsoil beneath the underground plant.

CEC.PF'306.. The' answer. is obvious and in the negative..

discharge in areas near the facility because of the lower bouyancy of a filtered plume.

See Licensee PF 283-286; Staff PF 242.

86.

CEC'6 fcnile answer to most of these problems was to assume that the containment would fail anyway from overpressure, so that the problems were of no significance.

CEC PF 310-314.

While this is true if the containment is inevitably going to fail, the adverse interactions between a CFVS and other plant systems may occur in situations where the containment was not about to fail.

In those situations the problems remain real and unaddressed.

Also unaddressed was the possibility of hydrogen explosions in the containment or in the vent line itself, which were conceded to be potential problems even by 2EC witness Nix.

Tr. 2723, 2724 (Nix).

CEC's answer is again that a hydrogen fire or explosion is of no consequence if a core has melted.

CEC PF 315, 216.

Tha t is clearly not a satisfactory answer.

87.

The above enumeration of open questions and problems, pl"s the undisputed uncertainty as to the cost of a CFVS (see Licensee FF 287-and Staff PF 243), clearly indicate to the Board that CFVS development is at an embryonic stage.

l It would be premature to require consideration of such a system for Rancho Seco at the present time, or even to order site-specific feasibility studies of such a system for Rancho Seco.

This conclusion is reinforced by the facts that the Commission is conducting an extensive, high priority program to address the areas of uncertainty in containment overpressuriza-tion protection; that a rulemaking proceeding on methods for mitigating the consequences of core melt accidents, including CFVS, is impending; and that the Staff is conducting a study of possible implementation of a CFVS at the Indian Point 2 and 3 and Zion 1 and 2 plants, which study may clarify many generic questidns in this area.

Staff PF 247, 248; Licensee PF 288, 289.

88.

CEC acknowledges these efforts by the Commission and the Staff.

CEC PF 320-322.

It insists, however, that Licensee should be ordera'

' give expedited consideration to implementing a CFVS uw perform within one year "a site and facility specific study intended to develop a proposed design for a CFVS at Rancho Seco."

CEC PF 326.

The justification for such an effort is that Rancho Seco possesses a "somewhat higher probability of an accident" because of "the safety concerns arising from the sensitivity of the OTSG."

CEC PF 325.

As we noted above, the alleged safety concerns about the sensitivity of the CTSG have been addressed.

Moreover, there is not onc iota of evidence in this proceeding tending to suggest that Rancho Seco has a higher probability of experiencing an acci-dent. leading to overpressurization failure of the containment than any other PWR.

To the contrary, a study of possible accident sequences and their consequences at B&W PWR's, per-formed by the -Probabilistic Analysis Staff in the wake of the Crystal River-3 transient, concluded as follows :,

It is~ known that B&W-plants have somewhat more frequent ' trips than do other PWRs, particularly since the THI-inspired alterations to the trip setpoints.

These excess trips seem to be originating from minor secondary side transients and non-safety-grade instrumentation faults.

These transient initiators do not correlate with the occurrence of massive, common-cause failures in the engineered safety features - with a couple of noteworthey exceptions - so they are not expected to increase the frequency of the risk-dominant severe accidents in B&W plants above the level expected for other PWR designs.

These considerations of B&W plant charac-teristics are summarized in Table 7.1.

We conclude that B&W plants are not signifi-cantly different from other PWRs la their vulnerability or susceptibility to severe accidents - those that dominate the nuclear risk.

Staff Ex. 4 at 7-8, 7-9, 7-13.

Thus, the justification alleged by CEC for performing a separate study at Rancho Seco is not persuasive.28 89.'

In conclusion, the Rancho Seco containment building meets.all existing Commission requirements and I

criteria and is capable of withstanding all but most extreme

. I accident sequences.

The probability of containment failure at

}

~ Rancho Seco 'due to overpressurization from a feedwater 28 CECL also points to the proximity of two population centers to-the Rancho Seco plant as a-facror suggesting, but not

- mandating, performance of a study at the present. time.

CEC PF 325.

We note, however, that the population around Rancho Seco is at least one order of magnitude smaller than _that surrounding the Indian Point' and Zion sites, for which CFVS feasibility studies ~ are currently being -conducted.

See SMUD Ex. 11 at 8-13;

- Tr.f2593-2599 (Nix). l s

v 4

g..

n m.

4 y

4 transient, the subject of this proceeding, is remote.

Allowing the Commission rulemaking. proceeding to determine what over-pressurization protection, if any,'is necessary is an appropri-ate course for this Board to follow, and one that under the circumstances. poses no risk to the public health and safety.

IV.

PROPOSED CONCLUSIONS OF LAW 90.

The Board has addressed several of the s

California Energy Commission's proposed conclusions of law in the foregoing discussion of the parties' proposed findings of fact.

In its conclusions of -law 2-5, CEC proposes that we find the short-term actions directed in the Commission's Crc r of May 7,1979, to be inadequate; that Licensee has not cc. plied satisfactorily with two of the four long-term modificat.ons directed by that Order; and that the Order should be =r nded to require 18 additional actions and modifications.

In proposed conclusion of law 6, CEC suggests that Licensee's compliance with.the.new requirements be the subject of the continued jurisdiction of this Board; or, in proposed conclusion of law i

i.

. 7, CEC. suggests that we delegate. our continued j urisdic*. ion to an extra-agency panel.

CEC has provided us with abso.'.utely no legal analysis of our-. authority to' adopt its numerous ptoposals

'or the; standards which should govern our consideration of

em.

91.

The Board's ' decision here must be based on the whole record and supported by reliable, probative, and.

substantial evidence.

10 C.F.R. S 2.760(c).

CEC's proposed initial decision does not meet this standard.

As the foregoing discussion illustrated, CEC tended to focus on minority positions or inferences in the record, draw sweeping and of ten illogical conclusions therefrom, and ignore the reliable, probative and substantial evidence.

Our discussion also revealed that CEC tended to change the issues specified by the Board for hearing and to suggest an inappropciate evidentiary burden for Licentee to meet.

There is no foundation in law or in fact for a standard which would require Licensee to prove that its management, operators and equipment are superior to the rest of the operating nuclear power plant industry.

Obviously, we could not find for Lice see under such a standard unless we investigated some seventy other facilities.

The Commission did not ask us to oversee an industry-wide contest, and we would know little more about the safety of Rancho Seco if we attempted to assign a comparative ranking to it.

92.

The standard here is one which the Commission enunciated in its Order of June 21, 1979, in this docket:

whether the actions and modifications directed in its Order of May 7, 1979, are necessary and sufficient to provide reasonable assurance that Rancho Seco will respond safely to feedwa ter transients.

CEC has not addressed this standard in its I

-proposed findings of fact and, consequently, its proposed conclusions of law are unsupported.

. l i

93.

In fact, only three of the eighteen CEC-proposed additional modifications were suggested to us by any witness who testified in this proceeding.

See, CEC CL 5(a) (Webb); CEC CL 5(p) (Minor); CEC CL 5(s) (Nix).

The remainder apparently represent nothing more than post-hearing " ideas" advanced by CEC or its counsel.

One of them is not even reasonably identified.

See CEC CL 5(k).

These recommendations, even if supported by the record, would have to be integrated with the many other post-TMI requirements before they could be imple-mented.

Tr. 3667, 3668 (Capra).

First, however, their desirability would have to be examined on the basis of an integrated systems analysis.

Tr. 3673-3675.

Keeping in mind this agency's statutory obligation to protect the health and safety of the public, we cannot go about such wholesale alteration of a nuclear power plant and its operations on so little justification and with so little knowledge of the consequences of our actions.

The Board is ama:ed that the California Energy Commission would propose that we do so.

1 94.

We are aware, from the record, tha t the Commis-sion is proceeding with an Action Plan to provide a compre-hensive and integrated approach to actions judged appropriate by the Commission to correct or improve the regulation and operation of nuclear facilities based on the experience from the accident at TMI-2, the official studies and investigations of - the accident, and the Commission's extensive review and consideration of'the resulting issues.

If the modifications -

V proposed by CEC had been identified at the outset of this proceeding, it would have been difficult tc have addressed them, in this adjudicatory forum,.in a coherent and coordinated fashion.

Apprised of them for the first time after the hearing is concluded, we find that our record does not begin to do so.

93.

The Board finds, then, that its findings of fact do not support the conclusions of law proposed by the California Energy Commission.

Accordingly, we adopt the proposed conclusions of law submitted by Licensee and the NRC Staff.

4 Respectfully submitted, SHAW,'PITTMAN, POTTS & TROWBRIDGE Thomas A.

Baxter a$tes US AkR Matias F. Travieso-Dia:: )

Counsel for Licensee 1800 M Street, N.W.

Washington, D.C.

20036 (202) 331-4100 1

Dated:

September 5, 1980 _

D o

A

CK21pp E

UW;Rc

-6 r LEAR REGULATORY COMMISSION 320,gI b _9 UNITED STATES OF AMERICA

~

y c;% cik 6

ECC;;tEng ;

BEFORE THE ATOMIC SAFETY AND LICENSING B0 CI

/p

'k' In the Matter of

)

SACRAMENTO MUNICIPAL UTILITY DISTRICT

)

Docket No. 50-312

)

(Rancho Seco Nuclear Generating

)

Station)

)

CERTIFICATE OF SERVICE I hereby certify that copies of the foregoing " Licensee's Reply to the Proposed Findings of Fact and Conclusions of Law of the California Energy Commission and the NRC Staff" and "Licens se's Memorandum of -Law in Association With Its Reply Proposed Findings of Fact and Conclusions of Law" were served this 5th day of September, 196L by deposit in tlia U.S. mail, first class, postage prepaid, to the parties identified on the attached Service List.

, k.

Thomas A.

Baxter Dated:

Septerber 5, 1980 9S05 So i

UNITED STATES OF AMERICA NUCLEAR REGULATORY CO!O1ISSION BEFORE THE ATOMIC SAFETY AND LICENSING 30ARD_

In the Matter of

)

SACRAMENTO MUNICIPAL UTIL.TIY DISTRICT

)

Docket No. 50-312

)

(Rancho Seco Nuclear Generating

)

Statien)

)

SERVICE LIST

14* *ath S. Bowers, ~ @ e Christcpher Tii4cen, Esge. ire Cr* 4 -an Dian Grueneich, Esqc. ire Amic Safety and Licensi:q Ecard c'14'ornia Energy Cc:rissien 11 Ecwe Avenue U.S. Ncclear Regulaterf C=4 *sicn Washington, D.C.

20555 Sacr:rento, California 95825 Dr. Richard-F. Cole

- ' t E. Brown, Escuire At cd.c Safety and Licensing Scard Panel Isaw.ce Coe Iangher, Es= tire U.S. Nuclear Pegulat::ry C=iesien "4, Christcpher arf Phillips, P.C.

Washington, D.C.

20555 1900 M Streec, N.W.

Washingten, D.C.

20036 Mr. Frederick J. Shen At d c Safety and Licensing Scard Panel Cocketing and Service Secticn U.S. Nuclear Regulatcrf C.Trcissicn Office cf the Secre*r f l

~

Washingten, D.C.

20555 U.S. Ne'ea'- Pegulatory FWasica Washington, D.C.

20555 David S. Kaplan, Esqdre Secretary and General Counsel Sacra:nento.M:icipal U*4 ty Disdct P.O. Sex 15830 Sacra:nento, c 4 #crni 95813 Richard L. Black, Esquire C##4ce of the E:mcutive Legal Director U.S. Nuclear Pegulatcry r=4 asica j

Mashing:cn, D.C.

20555 i

l l

,

ML19331E302

Text

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