ML19270G120
| ML19270G120 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 04/05/1979 |
| From: | Duflo M NRC ATOMIC SAFETY & LICENSING APPEAL PANEL (ASLAP) |
| To: | |
| References | |
| NUDOCS 7906050005 | |
| Download: ML19270G120 (23) | |
Text
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NRC PCDLIC DCCfBIENT RO0li UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION l' c ATOMIC SAFETY AND LICENSING APPEAL BOARD
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Michael C. Farrar, Chairman Q b +*[.*b
.g Richard S.
Salzman Dr.
W. Reed Johnson
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'll' SEh!O A,t R 3 ;273
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In the Matter of
)
)
FLORIDA POWER & LIGHT COMPANY
)
Docket No. 50-389
)
(St. Lucie Nuclear Power Plant,
)
Unit No. 2)
)
)
Mr. Martin Harold Hodder, Miami, Florida, pro se, and as counsel for intervenors Rowena E.
- Roberts, et al.
Messrs. Harold F. Reis', Washington, D.
C.,
and Norman A.
Coll, Miami, Florida, for the applicant, Florida Power & Light Ccmpany.
Mr. William D. Paton for the Nuclear Regulatory Commisslon staff.
MEMORANDUM AND ORDER April 5, 1979 (ALAB-537)
Two issues remain open in this construction permit proceeding.
One concerns the soundness of the St. Lucie 2 steam generator tubes; the other involves the stability of the applicant's electrical grid and, ultimately, the adequacy of the facility's emergency power systems generally.
7906050cc5 g
.l
.. We completed our review of other matters some time ago, affirming in ALAB-435, 6 NRC 541 (1977), the Licensing Board's decision--1/to authorize construction of a second pressurized water reactor at the Hutchinson Island site on Florida's east coast.--2/ Review undertaken on our own ini-tiative led us at that time, however, to retain jurisdiction over the steam generator tube issue.
6 NRC at 544-46.
j I
Three weeks later, we took up the second question now before us, on the basis of certain allegations that Robert D. Pollard (formerly a Commission staff member) had included in a letter i
to the Attorney General of the United States.
Mr. Pollard's charges dealt, inter alia, with the reliability of the 3/
offsite electrical power system serving the St. Lucie facility!
i
}
In ALAB-435, we instructed Florida Power and Light to submit a memorandum addressing several aspects of the steam generator tube integrity issue.
It did so, and the 1
_1/
--2/
Pursuant to 10 C.F.R.
s2.79 6 (b) (5), the Commission denied intervenors' petition for review of our decision as it pertained to alternative site analysis.
See the letter from the Secretary of the Commission to counsel for the intervenors dated December 23, 1977.
Our decision was ultimately upheld upon judicial review.
Hodder v. NRC, D.C. Cir. Nos. 76-1709 and 78-1149, December 26, 1978 (unpublished).
--3/
See our order of October 28, 1977.
Since that time, we have also taken up here the radon-release issue which is pending in a number of other proceedings as well.
That issue is being handled separately and is not dealt with in this opinion.
.. NRC staff responded.
Because a review of their submissions left us with a number of additional questions,on March 10, 1978 we directed the applicant to provide us with still further information.
At the same time, we took a similar step in connection with the grid stability issue.
Previously, the staff had voluntarily filed a number of documents that it had compiled in response to Mr. Pollard's letter.~~4/ As with the steam generator tube matter, the submissions prompted us to pose a number of questions to the applicant (and, in one instance, S/
the staff)T-
~~4/
Specifically, the staff submitted on October 25, 1977 "A Further Evaluation of the Florida Power and Light Company Electric Power System," and on November 3, 1977 ten documents it had referred to in that evaluation.
--5/
Mr. Pollard's letter had led to action on another front as well.
By order of November 8, 1977, the Commission directed the office of Inspector and Auditor to investigate the allegations that NRC em-ployees had improperly failed to notify the Board below of relevant information.
We therefore did not pursue a similar inquiry.
See our order of November 25, 1977; see also our order of July 31, 1978.
After reviewing the report that came out of that investigation, the Commission found that the lack of notification resulted from confusion, not frcm willful misconduct, on the part of the staff.
It therefore held that further action was unwarranted and instructed us to proceed accordingly.
Commission order of October 20, 1978.
We, of course, are abiding by its conclusion and giving the matter no further consideration.
_4 Th1 March 10th order set a schedule for the filing of replies by the staff and intervenors.
We there also requested that those parties discuss whether they believed j
that further formal proceedings were necessary.
By June 12, 1978, we had received the materials sought from the applicant and' reply memoranda from the staff cover-i ing both topics.
The intervenors had submitted no similar i
--6/
papers.
Rather, on August 11, 1978, they filed a " Motion for a New Contention" on the offsite power grid and a I
" Motion for stay" requesting suspension of the construction permit pending completion of the hearing they sought on the new contention.
The applicant anc. Staff opposed both motions.
t l
On September 20, 1978, Martin Harold Hodder (who is t
counsel for all the intervenors as well as an intervenor himself) notified us by telephone that he wished to file additional pleadings.
At Mr. Hodder's request, we infor-mally agreed to delay any action pending receipt of his papers.
Nothing more was heard for several months until, on January 29, 1979, intervenors filed a response to certain matters contained in Florida Power & Light's earlier papers.
The response was accompanied by a motion (which the other
_6/
See our order of July 31, 1978, paragraph 2.
.. parties have opposed) for leave to file it and to do so out of time.--7/ We are therefore now able to address the pending substantive issues and the intervenors' motions as well.
t I.
STEAM GENERATOR TUBES As explained in ALAB-435, we retained jurisdiction over the steam generater tube issue primarily as a result of concerns raised by information on additional instances i
8/
i of tube " denting"--
that we had received in the Prairie 9/
Island proceeding.--
To recapitulate, denting -- which has been particularly prevalent at seawater-cooled plants but had been thought to be a legacy of the phosphate method of secondary water treatment -- was reported for the first time at two plants that had always used "all volatile" secon-dary water treatment (AVT).--10/ Because of relevant similarities
--7/
Just before filing these latest papers, the intervenors advised us by telephone that they would be submitting them.
_8/
I.e.,
pinching due to growth of corrosion products in the crevices between the tubes and their support plates.
_9/
See Northern States Power Ccmpany (Prairie Island Units 1 a:.d 2), ALAB-427, 6 NRC 212, 216-18 (1977).
That decision supplemented ALAB-343, 4 NRC 169 (1976),
our first in-depth consideration of questions relating to the soundness of steam generator tubes in pressurized water reactors.
10/
The affected facilities were Maine Yankee and Millstone 2.
6-between those plants and the proposed St. Lucie Unit 2 --
1.e., Combustion Engineering Company design, seawater cooling 4
and use of the AVT methed -- we were unable to complete our review of the matter without further study.
Consequently, in ALAB-435--11/
we directed the applicant to prepare a memorandum containing a full, current description of (1) the steam generators; (.2 ) the components of the condensate and feedwater systems; and (3) the mached by which the secondary cooling water is to be treated.
In each instance, the submission should emphasize those aspects of the plant's design and operating proc edures which will be directed toward i
avoidance of steam generator sludge formation, tube corrosion and denting; and the provisions, if any, which are being made to cope with denting should it nevertheless occur.
In its memorandum and affidavit of November 4, 1977, Florida Power & Light first identified three conditions that it said must exist simultaneously before tube denting will occur:
(1) an area near the tube where impurities can become concentrated; (2) a rigid carbon steel support plate; and (3) impurities -- historically present due to inleakage of condenser cooling water -- able to produce an acidic environment.
The applicant asserted thar the "eggcrate design" tube support structures to be used at St. Lucie 2 would eliminate the tube-to-support-plate 11/
6 NRC at 546 (footnote omitted).
~
gaps that could create the first condition and be flexible enough to avoid the second condition if corrosive products nevertheless developed.
The applicant went on to say that it plan.ed to avert the third condition through condenser design features and strict operating procedures. --12/
Addi-tionally, it indicated it was supporting industry programs i
seeking solutions to the denting problem.
With respect to elimination of tube corrosion and steam generator sludge formation at St. Lucie 2, the company described a number of features and plans; these included polished and heat-treated
{
Inconci 600 tubes, feedwater recirculation and cleanup, deaeration of the condensate storage tank, and high steam generator blowdown.
The NRC staff's assessment (submitted on November 29, 1977) was that the applicant's " proposed design modifications are likely to improve the integrity of the steam generator systems."
The staff said it would give further consideration to the steam generator tube integrity issue at the final (i.e., pre-operating license) safety review stage.
After reviewing the responses to ALAB-435, we asked (in our order of March 10, 1978) several questions that focused more specifically upon the particular plans that 12/
Jhe company did note also that St. Lucie 2 could accom-modate demineralizers if that sort of hardware were to be deemed necessary to maintain secondary water purity.
-S-the applicant had described.
At the end of that month, Florida Power & Light again submitted a detailed affi-i davit; three weekt later the staff again endorsed the l
proposed system, saying it " represents the state-of-the art design and is sufficient to establish the level of assurance of safety requisite at the construction permit 3
I i
stage."
The intervenors have not addressed the question l
in any of their papers.
I To date, our treatment here of the steam generator tube issue has been much the same as it was in Seabrook --
i.e., a series of questions prompted by information received in Prairie Island, and responses from applicant and staff.
We find the papers thus far submitted are adequate for a decision; there is no need for further forma 1' proceedings.
The decision we reach follows our approach in Seabrook.
As 4
we said there: --13/
[W]e have analyzed the proposed steam generator and condenser design modifications within the framework of the general conclusions reached in ALAB-343 and ALAB-427 pertaining to the causative mechanisms of tube corrosion and denting.
On the basis of that analysis, we are satisfied both (1) that the applicants are taking positive measures to deal with the problem of maintaining steam generator tube inregrity; and (2) that these measures are appropriate ones given the present understanding of the nature and root of the problem.
13/
Public Service Company of New Hampshire (Seabrcck Units 1 and 2), ALAB-442, 6 NRC 728, 729-30 (1977).
of course, our analysis here also reflects our review in Seabrook.
See Tiso Kansas Gas and Electric Company (Wolf Creek Unit 1), ALAB-462, 7 NRC 320, 337 (1978).
.. In Scabrook, we stressed too the importance of con-tinuing industry and governmental study of the problems of corrosion and dentirg.
As mentioned above, in this proceeding applicant and staff have assured us that they are keeping abreast of developments in this area.
We went on to indicate in Seabrook that the staff should not only scrutinize current research but also at the earliest pos-sible date give effect at "all * *
- pressurized water reactors in possession of construction permits" to any 14/
important new disclosures in this field.
We emphasize here the continuing pertinence of those remarks.
Finally, we remind all parties that a permit to construct this plant is not a license to operate it.
In the event that the issue is not resolved to the satisfaction 9
of all concerned, a further opportunity to examine the question at a hearing will occur when an application for an operacing license is filed.
14/
M. at 7 3 0.
.. II.
ELECTRIC AL GRID STABILITY AND EMERGENCY POWER SYSTEMS i
The applicant and staff have filed a substantial amount of information pertaining not only to the physical features of the company's electrical grid but also to j
certain system occurrences and generic concerns.
They i
prepared scme of their descriptions, explanations and assessments pursuant to our order of March 10, 1978; other documents were submitted as a result of either recent grid disturbances or Mr. Pollard's allegations (see p. 2, supra).
After reviewing these extensive submissions, we I
still have unanswered questions concerning the stability of Florida Power & Light's electrical grid and, consequently, the reliability of AC power for Unit 2.
In this connection, we note that the staf f is of the opinion that there is 'less l
overall assurance that St. Lucie will have electric power i
available from the external grid than there is for the general population" of nuclear plants located in nonpeni-15 /
sular geographical areas 7 and that there has been no com-16/
pensating augmentation of the onsite emergency power system!
15 /
Fitzpatrick Affidavit of June 12, 1978, p. 5.
16/
Id. at 6.
Although these circumstances were known to tne staff at the time the Safety Evaluation Report was prepared, through confusion they were not mentioned there.
See fn.
5, supra.
.. Because of the questions we have, further formal proceedings are necessary.
We do not pause to set forth
(
at this juncture the full reasoning which leads us to call for an evidentiary hearing; the recitation of questions which follows will serve as sufficient explanation for the parties.
Of course, our final decision in the case not l
only will give the rationale for the result we reach, but also will provide the background information necessary i
for a full understanding of the problems involved.
We reach th, conclusion that a hearing is required on our own analysis of the applicant's and staff's papers.
That result, however, comports with the intervenors' belated 17/
motion to introduce a new contention.--
In the totality of circumstances, the following course is appropriate.
The intervenors ' motion to introduce a new conten+, ion is denied as moot, as the matter of electric grid stability and electric power reliability is to be explored on our
--17 As indicated earlier in this opinion, our order of March 10th (a year ago) gave the intervenors the explicit opportunity to comment on the applicant's submission on electrical grid stability.
They did not do so within the time prescribed, but more than three months later sought to raise a new contention on this issue.
own motion.
As we indicate later in thi opinion (see p. 22,
i i
infra), the intervenors will be provided the opportunity to j
participate in that exploration.--18/.
i i
Before scheduling and conducting the evidentiary 8
i hearing, however, the staff and applicant are (1) to i
prepare answers to the questions set forth below and (2) i i
J to submit those answers as part of an inclusive, sel#-
contained package of prepared testimony containing all information relevant to the adequacy of the facility's 1
emergency power systems.
We adopt this course for the same reasons which led us recently to take a similar 19/
i approach in the North Anna proceeding.
The parties I
{
here, too, should focus primarily on the areas covered by our questions, but, as we said in North Anna, "their orepared testimony must be broader in scope."
In both 1
--18/
We deal with the intervenors' stay motion later in this opinion.
In that connection, we have given due consideration to the latest set of papers they sought leave to file.
19/
Vircinia Electric and Power Company (North Anna Units 1 and 2), ALAB-529, 9 NRC (February 28, 1979) (involving different substantive issues).
.. proceedings, this must be done because, "while we already have before us a wealth of material", it "has come before us in somewhat informal fashion."
Additionally, here as there "the information is somewhat disjointed in the i
sense that it is necessary to locate and peruse a large number of varied documents to obtain a full picture
- Therefore, we can repeat our North Anna instruction:-~20/
j In order to create a formal record which will lend itself to ready review by higher tribunals, we request the parties to make their prepared testimony reasonably self-contained.
In other words, the prepared testimony should itself contain significant background information and references and be structured so that it can be understood with minimal reliance upon documents filed at earlier times.
If that is done, then, at the conclusion of the upcoming hearing, all the evidence necessary to understand and decide the issues will be found in the formal record made before us.
The testimony should, then, be in the format just indicated.
Our principal concerns, which should receive the parties' primary attention, ar. as follows:
20/
Id. at (slip opinion, pp. 2-3) (footnote omitted).
. A.
General Design Criterion (GDC) l7--21/
1.
This criterion, entitled " Electric Power Systems,"
requires in its third paragraph (emphasis added) :
i Electric power from the transmission network to the onsite electric distri-bution system shall be supplied by two physically independent circuits (not necessarily on separate rights of way) designed and located so as to minimize to the extent practical the likelihood of their simultaneous failure under operating and postulated accident and environmental conditions.
A switchyard common to both circuits is acceptable. 22/
i All three transmission lines connecting the St. Lucie station to the applicant's grid originate at the Midway I
Substation.
The May 14, 1978 incident, in which all power at that substation was lost despite redundant in-coming scurces, demonstrates that these circuits are indeed susceptible to simultaneous failure. --23/
The testimony should address whether the St. Lucie station nonetheless meets this GDC-17 requirement.
--21/
See 10 C.F.R. Part 50, Appendix A
(" General Design Criteria for Nuclear Power Plants").
--22/
As we now view it, subject to being persuaded other-wise, the " common switchyard" provision refers to the switchyard at the site and not to a distant facility (such as, in this instance, the Midway Substation).
--23/
See the applicant's May 25, 1978 " Report on System Disturbance, May 14, 1978."
. 2.
For its part, the first paragraph of GDC-17 appears to establish an c sttainable set of conditions for electrical power systems generally.
It reads as follows j
(emphasis added) :
An onsite electric power system and an i
offsite electric power system shall be provided to permit functioning of struc-tures, systems, and components important J
to safety.
The safety function for each system (assuming the other system is not functioning) shall be to provide sufficient capacity and capability to assure that (1) specified acceptable fuel design limits and design conditions of the reactor coolant pressure boundary are not exceeded as a result of anticipated operational occurrences and (2) the core is cooled and containment integrity and other vital functions are maintained in the event of postulated acci-i dents.
This paragraph requires that an assessment of the sufficiency of the offsite power system start
-z.h the assumption that the onsite system is not functioning.
That assessment must then consider the effect of " anticipated operational occur-rences."
But loss of the offsite power system itself may reasonably be considered to be such an occurrence.
The parties should, therefore, explain how the St. Lucie plant can comply with the literal requirements of this paragraph as written.
If it cannot, they should attempt to justify the situation in terms of the purpose of the requirement.
. B.
Failure of Offsite Power with Simultaneous Onsite Power Failure i
In our order of March 10, 1978 (p. 5), we directed the applicant to discuss the consequences of the fol-lowing sequence:
(1) failure of offsite power (and a presumption of resulting loss of the power generated by the station) followed by and combined with (2) failure of onsite power sources (i.e.,
the emergency j
diesel generators) to start on demand.
The focus was to be on safety related events that might occur be-tween the loss of all AC power and the eventual res-toration of an electric power source.
i Both the applicant and staff responded that this sequence, which supposes the simultaneous failure of two onsite emergency power sources, is not a " design basis event" and thus had not been studied in detail.
24 /
Nevertheless, both briefly discussed its consequences. -
--24/
Applicant suggests that the first safety related failure encountered would be excessive core heating due to the loss of water from the condensate storage tank, and that this would occur about 16 hours1.851852e-4 days <br />0.00444 hours <br />2.645503e-5 weeks <br />6.088e-6 months <br /> after the loss of AC power (Flugger Affidavit of March 31, 1978, p.
- 3).
(FOOTNOTE CONTINUED ON NEXT PAGE).
.. 1.
As we see it, the likelihood of loss of all AC Power at St. Lucie may be expressed as the product of two factors:
(1) the probability that there will be an offsite power failure involving the FPL network generally or the Midway substation in particularly and a resulting loss of station power -- which probability seems, based on historical events, to lie in the range 1.0 to 0.1 per year; and (2) the probability that neither of the two onsite AC power systems (diesel generators) will start.
The probability that any one diesel generator will fail to start on demand is taken by the staff to
-2 25/
be one per hundred demands, i.e.,
10 If these t
figures are accurate, then the combined probability for the " loss of all AC power" scenario is in the range 24/
(FOOTNOTE CONTINUED FROM PREVIOUS PAGE).
The staff's judgment is that the first failure would be that of a primary pump seal, at about one hour after the loss of AC power -- resulting in a small loss of coolant accident.
(Fitzpatrick Affidavit of June 12, 1978,
- p. 11).
25
--/
Fitzpatrick Affidavit of June 12, 1978, p. 4.
Also see Regulatory Guide 1.108, Section 3.
.. 26 /
~4
-5 10 to 10 per year.--
In this regard, the staff's Standard Review Plan for Nuclear Power PJants sets forth numerical guidelines for determining whether an event "resulting from the presence of hazardous materials or activities in the vicinity of the plant" should be con-sidered in designing the plant (i.e., whether it is a 27 /
" design basis" event).-~
Under these guidelines, events with a realistically calculated probability value of at i
~7
-6 i
least 10 per year (or 10 per year for a conservative calculation) must be so considered.
The " loss of all AC power" sequence is not precisely i
within the category of events contemplated by the Standard Review Plan.
However, its ultimate result -- assuming that power is not timely restored -- is an unprotected loss of coolant accident, the consequences of which are likely to exceed the guidelines of 10 CFR Part 100.
We 26/
This conclusion further assumes that the failure of two diesel generators to start would be statis-tically independent events, an assumption which leads to the lowest like.ihood of combined failure, and which might be noncc aservative if there exists the potential for common failure modes for the on-site systems.
27 / NUREG 7 5/0 97, Section 2. 2.3, paragraph II.
. do not understand why this sequence of events (i.e.,
loss of offsite power combined with failure of diesels to start), which appears to have a probability well above the guid.eline values, should not be taken into con-sideration in the design of the plant.--28/
The parties are to address this point, setting forth their reasons for adhering (if they do) to a contrary position.
2.
In line with the above discussion, the testimony is to analyze events that would occur between the " loss of all AC power" and the violation of either the fuel design limits or the design conditions of the reactor coolant pressure boundary (or any portion thereof).
In particular, the parties shou]d, if possible, reconcile their differing responses to question B.l(b) of our 29/
March 10, 1978 order,-- or, if not, point up precisely where ::he disagreements lie.
--28/ We have accept;d the Standard Review Plan guideline values as reasonable in another case.
Public Service Electric and Gas Company (Hope Creek Units 1 ana 2),
ALAB-429, 6 NRC 229, 234 (1977).
_2_9/ S e e f n.
24, supra.
4 3.
The testimony should contain a discussion, sup-ported by such data as is available, related to the time that might be required to start a diesel generator assuming it failed to respond to the initial, auto-start signal.
4.
Finally, in the light of the discussion of points 2 and 3 above, the parties are to review possible measures for decreasing the likelihood of exceeding de-sign limits on the reactor fuel and pressure boundary under the assumption that there is some time available to activate an auxiliary power source subsequent to a total loss of AC power.
C.
System Reliability During Alert Status, According to the staff, the applicant is being re-quired to define conditions in which it will put ts power distribution system in an " alert status".--
At such times, loss of offsite power would presumably be more likely than normal.
We wish to be advised as to the existence of measures that might be taken to assure, or at least to increase, the reliability of the onsite power systems during an " alert status" period.
30
_/ Fitzpatrick Affidavit of June 12, 1978, Enclosure 3.
e
. ?
D.
Ongoing Improvement of System Reliability.
The testimony should provide a concise, up-to-date discussion of existing measures, or those planned for the near future, by which the reliability of the applicant's system may be enhanced.
Particular attention should be paid to the seemingly excessive number of personnel errors which appear to have led to the May 14, 1978 outage and to have contributed to the May 16, 1977 disturbance.
Some of our questions aay require information more I
readily available to one party than to the other, or involve issues more appropriately addressed in the first instance by one rather than the other.
We leave it to the combined judgments of the applicant and staff to allocate principal or sole responsibility for such topics and also to identify those that both will cover.
We suggest, however, that they confer to make sure that the prepared testimony as a whole deals thoroughly with all subjects.
Because they have already given considerable attention to the grid stability issue, the applicant and staff should be able to file their prepared testimony within 45 days
.. 31/
from the date of this opinion.--
If the intervenors wish to participate in the upcoming hearing, they are to advise us within that same time period of the nature and extent of their planned participation; we will then give them the opportunity to file prepared testimony in response to that of the applicant and staff.
The applicant and staff will also have a chance to respond on subjects that were within the other's principal responsibility (see the preceding paragraph).
After all prepared testimony is in hand, we will confer with the active parties and establish a definite hearing schedule.
It is our present intention to hold the hearing in the south Florida area.
As we have already pointed out, the course that we are following renders moot the intervenors' motion to admit a new contention on the grid stability issue.
Beyond that, we deny their motion for suspension of the applicant's construction permit pending resolution of that issue.
The reliability of Florida Power & Light's electrical grid is an issue that is not intimately bound up with the nature of the construction in progress; it will come to the fore when the time arrives to consider whether to license opera-tion of St. Lucie 2.
This does not eliminate the matter 31,/
If this proves insufficient, the parties will be free to seek an extension of time.
s.
from consideration at the construction permit stage, but it does mean that allowing construction to continue during our review of this question will not harm intervenors' interests; on the other hand, suspending construction surely
--32/
would harm applicant's.
In accordance with the foregoing, the jurisdiction over the issue of steam generator tube integrity retained in ALAB-435 is terminated; intervenors' " Motion for a New Contention" is dismissed as moot; the stay motion is denied; and the parties are directed to file erecared testimony as specified.
It is so ORDERED.
FOR THE APPEAL BOARD mas] [ AGw$
MargaptE.
Du Flo Secre ary to the Appeal Board 32/
See 10 C.F.R.
- 52. 78 8 (e), which embodies the criteria for granting a stay set forth in Virginia Petroleum Jobbers Ass'n v.
FPC, 259 F.2d 921, 925 (D.C. Cir.
1958).
See also the Cerrickson Affidavit of August 23, 1978.