ML19322C521
| ML19322C521 | |
| Person / Time | |
|---|---|
| Site: | 05000514, 05000515, Crane  |
| Issue date: | 01/12/1978 |
| From: | Lawroski S Advisory Committee on Reactor Safeguards |
| To: | Hendrie J NRC COMMISSION (OCM) |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170850 | |
| Download: ML19322C521 (10) | |
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g NUCLEAR HEGULATORY COMMISSION O **, y $,C j ADVISORY COMMITTEE oN REACTOR SAFEGUARDS
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WASHINGTON. D. C. 20555
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v January 12, 1978 i
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Honorable Joseph M. Hendrie 2
Chairman U. S. Nuclear Regulatory Comission Washington, DC 20555
Subject:
REPORT ON PEBBLE SPRINGS NUCLEAR PLANT, UNITS 1 AND 2 m
Dear Dr. Hendrie:
During its 213th meeting, January 5-7, 1978, the Advisory Comraittee on Reactor Safeguards conpleted its review of the application of the Portland General Electric Conpany for a pemit to construct the Pebble Springs Nuclear Plant, Units 1 and 2.
This project was also considered during a Subcomittee meeting held in Portland, Oregon, on October 28, (m).
1977. The Comittee previously completed a partial review of this project at its 190th meeting, as Iliscussed in its interim report to the Nuclear Regulatory Comission (NRC) dated February ll,1976. During its review, the Comittee had the benefit of discussions with represen-tatives and consulPants of the Portland General Electric Company, the Babcock and Wilcox Conpany, the Bechtel Power Corporation, and the NRC Staff. The Committee also had the benefit of presentations on the regional tectonics of the Pacific Northwest by representatives of the NRC Staff, the U. S. Geological Survey (USGS), Puget Sound Power and Light Conpany, Portland General Electric Conpany, Washington Public Power Supply System, their consultants, and members of the public at Subcomittee meetings held on September 1-2, 1977 in San Francisco, California, and on October 27-28, 1977 in Portland, Oregon. Matters related to the regional tectonics of the Pacific Northwest were con-sidered at the 209th and 211th Comittee meetings as reported in the Comittee's letter dated November 15, 1977 to the NRC Executive Director for Operations. The Comittee also had the benefit of the documents listed.
At the thre of the Conmittee's interim report, February 11, 1976, the NBC Staff, the USGS, and the Applicant had not yet completed their re-views of the seismic design basis and of matters related to the possible deposition of volcanic ash arising from aujor volcanic eruptions of Mount Hood or Mount Saint Iselens. These reviews have now been conpleted and the ACRS finds the Staff positions on these matters acceptable.
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f Jam a n M, W 8 mb Honorable Joseph M. Hendrie 2-The Comittee believes that the Applicant and the NRC Staff should re-view the Pebble Springs Nuclear Plant for design features that could further reduce the possibility or consequences of sabotage.
(Generic Item IIC-2 in ACRS Report, " Status of Generic Items Relating to Light-Water Reactors: Report No. 6," dated November 15, 1977).
Since the Comittee's earlier partial review, the Staff has identified 2..
13 additional issues,11 of which require resolution prior to construc-tion. These matters should be resolved in a manner satisfactory to the NRC Staff.
With regard to the generic problems cited in the Comittee's report,
" Status of Generic Items Relating to Light-Water Reactors: Report No. 6,"
dated November 15, 1977, iters considered relevant to the Pebble Springs Nuclear Plant, Units 1 and 2 are:
II-3, 4, 58, 6, 7, 9, 10; IIA-2, 3, 4; IIB-1, 2; IIC-1, 3A, 3B, 4, 5, 6; IID-2; IIE-1. These problems should be dealt with by the NRC Staff and Applicant as solutions are found.
b-The ACRS believes that, if due regard is given to the items mentic above and in its report of February 11, 1976, the Pebble Springs huu sar Plant, Units 1 and 2 can be constructed with reasonable assurance that it can be operated without undue risk to the health and safety of the
'y,.c public.
Sincerely yours, M&f-0?.
Stephen Lawroski 5
Chairman
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References:
1.
Pebble Springs Preliminary Safety Analysis Report, Volumes 1-9 and Amendrents 1 through 10.
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2.
Safety Evaluation Report, NUREG 0013, related to construction of Pebble Springs Nuclear Plant, Docket Nos. 50-514 and 50-515, I
January 1976, with Supplements 1 through 4.
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3.
USGS letter, dated January 3,1978 from Henry W. Coulter, to tir.
l Edson G. Case, ONRR, USNRC, re review of geologic and seismologic data relevant to Pebble Springs Nuclear Plant, Units 1 & 2.
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Honorable Joseph M. Hendrie January 12, 1978
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r; Referen:'es (con't)
Shannon & Wilson report to Portland General Electric Company 1
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entitled " Volcanic Hazard Study - Potential for Volcanic Ash Fall, Pebble Springs Nuclear Plant Site, Gilliam County, Oregon," dated January 1976.
Pebble Springs Nuclear Plant Fire Protection Review, PGE 2013, 5.
March 1977 with Amendment 1 dated November 1977.
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Portland General Electric Company letter dated Septettber 7, 1977, 6.
from J.W. Lindblad to Director of Nuclear Reactor Regulation, USNRC, re identification of significant items not formally documented C-
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with NRC.
Portland General Electric Company letter dated November 17, 1977,
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from W.J. Lindblad to Director of Nuclear Reactor Regulation, USNRC, re forwarding detailed description of Solid State Interposing
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Logic System.
Portland General Electric Conpany letter dated November 29, 1977, m
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7 from W.J. Lindblad to Director of Nucl2ar Reactor Regulation, USNRC, w
re evaluation of geological and seismological aspects and outstand-e-
ing issues.
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Portland General Electric Co:Ipany letter dated ILdr 30, 1977, 9.
from Joseph L. Williams, Executive Vice. President to Directof of
. Nuclear. Reactor Regulation, USNRC, relresponse to questions.raisedi
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'by nCRS.
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(V9 EXCERPT FROM
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'l MINUTES OF THE 213TH ACRS MEETING JANUARY 5-7. 1978
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IV. Meetino on Pebble Springs Nuclear Plant (CP), Units 1 and 2
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(Open to Puolic)
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[ Note:
Ragnwald Muiler was the Designated Federal Employee for this portion of the meeting.)
{ Note:
D. J. Brcehl, Portland General Electric.Co. (PGE) coordinated h:
the presentations for the Applicant;, C. Stahle, for the NIC Staff.]
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A. Subconmittee Recort in Subcomittee Chairman, discussed the status of Mr. Plesset, M
the Committee's review of the application for the Pebble Springs si Nuclear Plent, Units 1 and 2 (see Appendix XIV).
F.e noted thac the Comitt2e has written an interim report on this applicatica, F
and that the current portion of the review addresses those ice.s which were not completed when the interim report was issued in February, 1976. These items included e Seismic Design Requirements - USGS has recommended a design j y'. {-
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basis acceleration of 0.25g for the SSE,
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i e Improved ECCS Performance - this plant will use the B&W Mark
(' :.t C fuel, which has a lower linear heat rate than previous B&W
- fuels, e Asymetric Loads During Blowdown - this matter is.being pursued effectively, and a favorable resolution is expected l,
in the near future, I ' :.,
e Anticipated Transients Without Scram - a report on this matter is expected soon, I
e Protection Against Turbine Missiles,
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e Fire Protection,
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i e Industrial Security, and e,
l e Analysis for the Effect of Volcanic Ash.
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.. Mr._ Plesset _noted that f twenty-six. technical questions had.
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_been raised by Mr. Ebdrsole regarding the Pebblo Springs cpplica-
' tion, and that written cocponses to these questions have been provided by PC::: (see Appendix XV).
PdMe knws s
O JANUARY 5-7, 1978 MIWrES OF DIE 213TH ACRS MEETItG The Chairman noted that no requests have been received from members of the public to make oral or written presentations
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regarding the Pebble Springs application.
B. Status of imC Staff Paview U
S C. Stahle said that the most significant event that has occurred, since the review of the regional tectonics of the Pacific Northwest, is the resolution of the seismic design ques-tion.
He said that the Applicant, the NRC Staff, and USGS are in e
agreement that a ground acceleration of 0.25g is adequately con-servative for the SSE.
(For the USGS report on the geology and 4
seismology of the Pebble Springs site, see Appendix XVI).
With regard to the previously identified open issues, C. Stahle noted the following:
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e the seismic design basis has been resolved: 0.25g horizontal ground acceleration for the SSE, i
the Applicant has cor.Mtted to a missile l
shield if it' is shown to be necessary.
A current EPRI study regarding turbine missiles may lead to a reduction of the conservatism of turbine missile calculations.
y JG. - R. Mazetis,; NRC Staff, discussed the following three open items.),'
e credit for feedwater isolation to mitigate consequences of Chapter 15 events:
the NRC Staff will pursue with the Applicant a request to address the different closure times between the feedwater isolation valves to assure that a t
single component failure would not compromise feedwater isolation when needed.
e ne NRC Staff will require an additional commitment from the Applicant to use tGC Staff criteria for designing against limited passive failures during the long term after a ICCA.
e he NRC Staff has requested additional information on the operator reactions during Chapter 15 events.
The Applicant has indicated that this material will be submitted in the near future, and the NRC Staff will review it when it is
. f' recalved.
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MIturES OF THE 213TH ACRS MECTItG JANUARY 5-7, 1978 C. Stahle said that the Applicant has identified eight engineering changes which resolve geological-seismological asoects of the Pebble Springs Plant.
The NRC Staff has resolved six of i
these items.
One of the two remaining items, regarding the mini-purge system, is still under review. The NRC Staff foresees no problem with this system, and believes it will be able to report satisfactory resolution in the next supplement to the SER.
S. Varga, NRC Staff, said that the 54-inch diameter vent, to be used during the fueling operation is under consideration by the Applicant for use during operating times also.
If the Appli-cant recuests the use of this 54-inch valve during operation, the NRC Staff will require that the same requirements be met regarding valve operability, acceptable doses, and ECCS back pressure, as is required for the mini-purge system.
The applicant will be required to show that this 54-inch butterfly valve can withstand the maximum design pressure of the containment, and also be capable of closirg against this pressure.
Mr. Bender questioned the practicability of using a 54-inch valve in a vent line.
C. Applicant's Fesconse to the NRC Staff Recort e
D.
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Broehl took issue with the 0.25g horizontal ground
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acceleration requirement.
Although the Applicant believes that 0.2g is both conservative and conforms to 10 CFR 100,.ppendix A, the plant has been designed to the 0.25g required by the NRC s
8 Staff.
The Applicant disagrees with the NRC Staff's interpre-tation of the criteria.
With regard to the turbine missile questioc., he said that the principal contributor to the high probability of a penetration event, is the steam line penetration.
A certain amount of spall shielding would eliminate the problem.
'1he Applicant has committed to installing the spall shielding if it proves to Le required.
He said that one factor which was not considered in the NRC Staff's analysis, was a change in design in which the number of coisture separator reheaters was increased
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from two to four, which the Applicant calculates will reduce the L
probability of serious penetration from a turbine missile to the f
order of 2x10. He suggested that the bases for calculations of l
missile penetration probability have changed since Dr. Bush's I
report because of improved valve testing.
Another element which may have an effect is improved turbine disk integrity.
The spall shielding need not be ordered until two years prior to fuel loading, which is scheduled for 1986 or 87.
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. l JANUARY 5-7, 1978 MItUTES OF THE 213TH ACPS MEETItG g
D. Besolution of Postulated volcanic Ash Problem 8
S. Christensen, PCE, said that the solution to the current W,
volcanic ash problem, with regards to the acidity of the ultimate heat sink following fallout of volcanic ash, would be resolved Buffered Columbia River water has been by buffering this water.
calculated to have a pH of 6.4 under these conditions, unbuffered, I
the water would have a pH of 3.3.
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b In answer to a question, S. Christensen said that if there were a catastrophic volcanic eruption, if the wind were blowing toward the plant as postulated, and an ash fall in the postulated 4
amount occurred, the plant would be shutdown.
D. J. Broehl suggested that a volcanic eruption of the size postulated would present problems additional to the ash fall, such as difficulties with the transmission system, transportation, f.e,.i personnel comuting, etc.
Because of these complications, the The
, Applicant has assumed that the plant would be shutdown.
capability of maintaining a safe shutdown under the most severe circumstances has been evaluated. With regard to highway problers from deposited ash, road graders and,bulldo::ers will be available I.
,for clearing.
.'c E. NRC Staff's Resconse to ACPS's Cuestions
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(For questions and Applicant's response, see Appendix XV.)
'5. Varga said the NRC: Staff.found nothihg in the' Applicant's;
, answers; to the.' twenty-six questions submitted by the Committee;
- to alter the Staff's conclusions.
Mr. Ibersole suggested that clarificaticn of several points was in order:
e Localized vulnerability
.D. R. Swanson, PGE, said that gross damage to the control room would not prevent safe shut-down by means of the remote control center.
The Applicant has the capability and can maintain the capability for safely shutting down the plant from outside the control rocm.
The automatic control systems provided do not deny the preroga-e
. l tive of an operator to restore services he needs.
i o Worst chilling ef fects of differential temperatures on the tubes and the shell of the steam generators - C. II.
Bruny, Bechtel Corp., said that the number quoted in response to t.he question, 3t strain, is an average, uniform strain
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MINLJrES OF THE 213TH ACPS MEETI:G He said that along the length of the steam generator tube.
.s the tube to tube sheet veld has also been evaluated for
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startup as well as accident conditions, and it is considered f'
acceptable.
that the strain J. Rajan, Bechtel Corp., pointed out at rupture would be between 20 to 251, and that the current
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case postulates a strain of only 0.3%.
4 e;Ioss _ of.;.feedwater. flow control, _ subject to turbine. trip, iwhere no more than Enormal maximum level ~of pressurVis'
,i developed - R. Schomaker, Babcock and Wilcox, said that the' d
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analysis was performed assuming all valves were working and safety valves were operating.
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[T. Novak) NRC Staff, said that in reviewing.a plant.
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, for -overpressurization, the assumption is made that. aThe conservatism
< spring-loaded' safety. valves would' function.
of the analysis comes from the delayed signals that are
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derived to cause reactor trip.
Failure of a safety valve to operate is not required for the analysis.
- e. Inconsistency of. single..fallure criterion -[Mr. EbersoleL C
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/q offered ytis interpretation 'of the single. failure criterion
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applying to an occurrence that results in the loss of capabil-l ity of a.::c=pontent to perform its intended safety functica
.7 when called upon.
Implicit in that statement is that tne is on standby duty.
This definition is affected component not consistent with the class of systers, such as battery systems, on-site a-c power systems, service eter systers, and component cooling systems, because those systems are called upon 100% of the time, whether the plant is cperating or shut down.
For cable spreading rocrn - S.
Krishnamurthy, e Requirement Bechtel Corp., said that the auxiliary shutdown panel can l
accomplish a plant shutdown without dependence on either to<xa.
The architect-engineer intends to cable-spreading separate the two redundant auxiliary shutdown panels into two I
different rooms.
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said that i
o Freon compressor I4 cations - D. R. Swanson, PGE,
'. t the freon compressors for the chilled water system are both redundant and separated into different rocms.
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.a-O JANUARY 5-7, 1978 V
MINUTES OF THE 213TH ACPS MECTItG
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e Control room dose calculations - S. Varga, NRC Staff, said
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that while the methods of calculations for control room 1
dose differ betwcen the Applicant and the NRC Staff, the calculated doses are in approximately the same range.
e Electrical penetration protection - Members noted that the NRC Staff's requirement for combining seismic and LCCA leads
,i may not be consistent.
Mr. Ebersole cequested that the NRC l'
Staff report on its requirements for analysis of combined seismic and IOCA loads on safety systems and requirements.
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F. Industrial Security (Closed to Public)
D. Broehl said that the Applicant has reached no details in security plans for Pebble Springs.
The Applicant's security
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experts are currently working on upgrading the security at the Trojan Plant.
No work has been done beyond the current applica-tions and the meeting of the various Regulatory Guides relating to separation of equipment and electrical systems.
He said that he believes that the plant has a basic sabotage-resistant design. He l ".
noted that the Applicant is currently caught in a series of changes and development of new regulations.
.L C. Goodwin, PGE, said that he has read the Michaelson Report,
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and that he plans to review the events identified by Michaelsen to prevent such scenarios from occurring at Pebble Springs.
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suggested that in order to evaluate a plant against sabotage by inside personnel, one has to evaluate x.otives, capabilities for carrying out specific actions, and opportunities.
He believes that the best method to prevent sabotage by personnel considered trustworthy is to keep the personnel happy.
This can te acccm-b,,,
plished with good management practices.
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Members suggested that the Applicant should analyze his b1 proposed plant to determine areas which may be problems, and not wait to meet NRC Staff requirements.
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W. J. Ross, NRC Staff, said that the Applicant had develcped
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Q; good plans for Trojan in the Spring of 1975.
These plans met the existing guidelines. He noted that as far as the NRC Staff is concerned, industrial security is a developing area.
The NRC Staff'has been cognizant of the problems of this Applicant as well J.
as others.
The NRC Staff is handling this situation with PG&E as
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it is handling the situation with other applicants by educating q,,
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o JANUARY 5-7, 1978
, MItUrES OF THE 2131H ACPS PIETI!G them of the currently perceived threat levels. It is desired that
. the Applicants work with their architect-engineers to identify critical systems, components, and trains.
The NRC Staff is attempting to improve communications between themselves and the Applicants.
G. Caucus (Open to Public)
The Members provided their opinions concerning the matters discussed above and identified those matters which they believed should be addressed in a report concerning this. review.
The Committee concluded that they could write a report at this meeting.
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