ML20033C063
| ML20033C063 | |
| Person / Time | |
|---|---|
| Site: | Atlantic Nuclear Power Plant  |
| Issue date: | 11/25/1981 |
| From: | Cowan B, Kenrick J OFFSHORE POWER SYSTEMS (SUBS. OF WESTINGHOUSE ELECTRI |
| To: | |
| References | |
| NUDOCS 8112020623 | |
| Download: ML20033C063 (16) | |
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1 j
..u 7 UNITED STATES'OF AMERICA DOCMETED UShRC NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC. SAFETY AND LICENSING BOARE WI 30 P2:28
~ Y SECRETARY
?.L f rig & sggy;g'6 In the Matter of-URANCH ggo), r OFFSHORE POWER SYSTEMS Docket No.
50-437'f (Manufacturing License for j/
OEgy
)
Floating Nuclear Power Plants) p\\ v.s.klEQw 1987.
D IDENTIFICATION OF THE EVIDENCE OF THE APPLI 7%
Responding to the Atomic Safety and Licensing Board
(" Board") Order of November 3, 1981,.in this proceed-ing, and in compliance with 10 CFR Part 2, Section 2.74 3 (b),
2 the Applicant, Offshore Power Systems
(" OPS"), hereby iden-tifies, for the convenience of the Board and the-parties, the evidence to be introduced by the Applicant during the l
forthcoming hearing session scheduled to commence at 10:00 a.m. on December 4, 1981, in Bethesda, Maryland.
A.
Amendments to Application for a License to Manufacture Floating Nuclear Plants and Additional Direct Testimony 1.
The Application for a License to Manufacture Floating Nuclear Plants (hereinafter referred to as " OPS Application") consisting of (a) one volume (three-ring binder)
~
entitled:
" Application for Manufacturing License and Supple-mental Information" responsive to 10 CFR Part 50, Section 50.33, General IIformation, and (b) eight volumes (each volume is a 7
f i
s
- FOMh, I/
t j
three-ring binder) entitled:
" Plant Design Report" (here-
'inafter "PDR") responsive to 10 CFR Part 50, Section 50.34, Technical Information, and Appendix M, Paragraph 2, were admitted into evidence on June 15, 1976 (Tr. 1031) as OPS Exhibit Nos. 20 and 21, respectively.
The aforementioned "Appx __; ion for Manufacturing License and Supplemental In-formation" was superseded in Amendment No. 29 (dated Novem-ber 10, 1981) to the OPS Application by a document entitled
" Application for Manufacturing License, General Information, Revision 2."
Amendment No. 29 has previously been filed with the Board under an "Index and Certification" dated No-vember 16, 1981.
As noted at Tr.-1027, OPS Exhibit No. 21 included all PDR Amendments through Amendment No. 22.
Since the date of admission of OPS Exhibit No. 21, Amendment Nos.
23-28 and 30 (including Errata to Amendment Nos. 24 and 27) to the PDR portion of the OPS Application have been filed with the Board under "Index and Certifications" dated Septem-ber 11, 1976, October 28, 1977, June 30, 1978, January 24, 1979, Augu6t 24, 1981, and November 23, 1981.
Applicant.will introduce into evidence OPS Application Amendment Nos. 23-30, inclusive, at the forthcoming hearing session on December 4, 1981.
2.
APPLICANT'S ADDITIONAL TESTIMONY REGARDING XI.
TURBINE GENERATOR MATTERS dated November 20, 1981, is attached hereto and marked for identification as Exhibit OPS-68 (12/4/81).
3.
APPLICANT'S TESTIMONY IN RESPONSE TO THE NOVEMBER 12, 1981 BOARD QUESTION NOS. 4-7 -
y dated November 24, 1981, is attached hereto and marked for identification as Exhibit OPS-69 (12/4/81).
B.
Witnesses 4.
To sponsor the Applicant's evidence identified above, OPS will provide witness panels consisting of approp-riate witnesses selected by the Applicant from those indi-viduals who have been previously sworn and who have testified in this proceeding and also:
Dr. Brij'B. Seth See Professional Qualifications attached hereto and marked for identification as Exhibit OPS-67 (12/4/81).
Respectfully submitted, N
b JAA VTc ew-n ut Counsel for Applicant, Offshore Power Systems Dated:
November 25, 1981 1
1
' UNITED STATES OF AMERICA
= NUCLEAR REGULATORY COMMISSION
.BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of OFFSHORE POWER SYSTEMS Docket No. STN 50-437 (Manufacturing License for Floating. Nuclear Power Plants)
CERTIFICATE OF SERVICE I hereby certify that copies of " Identification of the Evidence of the Applicant (#10)" were served by de-posit in the United States Mail (First Class), postage pre-paid, upon the persons listed on Attachment 1 to this
. Certificate of Service this 25th day of November, 1981..
h)
I[
t
. ec6 W. Kenrick, Counsel for Offshore Power Systems
4 ATTACHMENT 1 OPS SERVICE LIST Sheldon J. Wolfe, Esq., Chairman Barton Z.
Cowan, Esq.
Atomic Safety and Licensing Board John R.
Kenrick, Esq.
U.S. Nuclear Regulatory Commission Eckert, Seamans, Cherin & Mellctt Washington, D.C.
20555 42nd Floor, 600 Grant Street Pittsburgh, Pennsylvania 15219 Dr. David R.
Schink, Member Atomic Safety and Licencing Board Thomas M.
Daugherty, Esq.
Department of Oceanography Offshore Power Systems Texas A & M University 8000 Arlington Expressway College Station, Texas 77840 P.
O.
Box 8000 Jacksonville, Florida 32211 Dr. George A.
Ferguson, Member Atomic Safety and Licensing Board Carl Valore, Jr.,
Esq.
School of Engineering Valore, McAllister, DeBrier, Aron Howard University
& Westmoreland 2300 5th Street, N.W.
P.
O.
Box 175 Washington, D.C.
20059 Northfield, New Jersey 08225 Dr. David L.
Hetrick, Alternate Member S.
Jacob Scherr, Esq.
Atomic Safety and Licensing Board Natural Resources Defense Council Professor of Nuclear Engineering 1725 I Street, N.W., Suite 600 The University of Ari=ona Washington, D.C.
20006 Tucson, Arizona 85721 Sandra Ayres, Esq.
Alan S. Rosenthal, Esq., Chairman Assistant Deputy Public Advocate Atomic Safety and Licensing Appeal State of New Jersey Board Panel P.
O.
Box 141 U.S. Nuclear Regulatory Commission Trenton, New Jersey 08601 Washington, D.C.
20555 Mr. George B.
Ward Alternate Chairman Nucler Power Plant Committee Atomic Safety and Licensing Appeal City.!all Board Panel Brigantine, New Jersey 08203 U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Dr. Willard W.
Rosenberg Atlantic County Citizens Council on Chief Hearing Counsel Environment Of fice of the Executive Lega1 Director 8 North Rumson Avenue U.S. Nuclear Regulatory Commission Margate, New Jersey 08402 Washington, D.C.
20555 Mr. John H. Williamson Docketing & Service Section Atlantic County Citizens Council Office of the Secretary on Environment U.S. Nuclear Regulatory Commission 211 Forest Drive Washington, D.C.
20555 Lir. wood, New Jersey 08221 Stephen M.
Schinki, Esq.
Director Of fice of the Executive Legal Director Division of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission U.S. Nuclear Regulatory Commission Washington, D.C.
20555 Washington, D.C.
20555
c:
OPS-68(12/4/81)
UNITED STATES OF AMERICA NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD e
In the Matter of
)
)
0FFSHORE POWER SfSTEMS
)
Docket No. STN 50-437
)
(Manufacturing License for Floating
)
Nuclear Powar Plants)*
)
APPLICANT'S ADDITIONAL TESTIMONY REGARDING XI. TURBINE-GENERATOR MATTERS Testimony on turbine generator matters was presented to the Board in hearing sessions during the period between December 8,1976 and May 17,
/
1977 1. Since testimony was originally presented, additional technical information, whicn relates to the question of turbine missile, has been developed as a resu't of the following events:
- 1) Cracks were observed in low pressure discs in a number of operating nuclear turbines./2 e
/1 Tr. 4006 - 6001 and Tr. 6151-6172.
/7 This was reported to the Board in Board Notification BN-80-4 from
~~ Mr. S. A. Varga, January 25, 1980.
y
- 2) Tests were conducted at the Electric Power Research Institute (EPRI) and Westinghouse Electric Corporation in which simulated discs at high speeds impacted with metal barriers. Data from these tests indicate that in some cases the energies with which missile fragments exit the tu:bine casing may be higher than previously estimated./3
- 3) A disc failure occurred in the low pressure unit of the Yankee-Rowe urbine Generator.O r
For the reasons presented below none of the relevant conclusions put forth in prior testimony are invalidated by these events.
OBSERVATION OF DISC CRACKING Subsequent to the conclusion of testimony on turbine-generator matters, cracks were discovered in the bore and keyways of a number of low pressure discs in operating turbines.
The cracking phenomenon has been studied extensively by Westinghouse Electric Corporation, both to determine the mechanisms responsible for crack initiation and to estimate the time required for a crack to grow to the critical size at which disc failure could occur.
/3 This has been the subject of the following memoranda and notices to the
-- Board:
S. M. Sohinki memorandum dated December 22, 1978; S. M. Schinki memorandum dated January 2,1979 and Board notification BN-80-4, Mr. S. A. Varga, January 25, 1980.
/4 This was reported to the Board in Board Notification BN-80-8 dated
~ February 19, 1980 and in a subsequent memorandum dated March 31, 1980, both from Mr. S. A. Varga. i
Westinghouse has concluded that the disc cracking was induced by stress corrosion and is developing design modifications to provide greater margin.
These include:
o Affected discs have been redesigned to achieve lower bore stresses and utilize lower yield strength material.
o Designs which eliminate bore keyways are now being utilized.
o Methods te keep the disc / bore keyways dry are being explored, since no cracking has been found in discs operating in dry steam.
o Partial integral rotors where the first three discs are made a part of the shaft are being considered. Only the last few, less critical discs would have to be shrunk on in such a partial integral rotor.
At the present time there are no FNP turbines on order. Thus it is expected that significant design improvements will have been implemented by the time that the first turbine is manufactured.
In its study of turbine disc cracking in existing units, Westinghouse has also developed inservice inspection procedures and recommended intervals inspection E. The recomended inspection intervals are based on I
between observed crack size and are intended to assure that cracks will not grow to the critical size before the next inservice inspection.
It was noted in prior testimony by both the Applicant and the Staff - that the FNP turbines will receive inservice inspection at approximately ten year intervals. This interval will be adjusted if necessary based initially on analyses of each FNP turbine using as-built data and subsequently on the results of each inservice inspection.
/5 The Staff Safety Evaluation Report, " Criteria for Low Pressure Nuclear
- Turbine Disc Inspection" was transmitted to Westinghouse Steam Turbine Division by Mr. S. A. Varga's letter dated August 26, 1981.
/6 See for example the Staff's written direct testimony, pp. 32, 33 and Tr.
5534-5538.
.i EPRI MISSILE PENETRATION TESTS w
Additional test data on interaction between simulated turbine missiles and steel barriers have-become available since May 1977.
Tests performed at Sandia under EPRI sponsorship and additional tests performed by Westing-house suggest the need to recalculate missile energy absorption by steel barriers such as the turbine casing. Westinghouse is in the process of recalculating the residual energy of disc fragments which penetrate the turbine casing.
These calculations are being performed on cach turbine utilizing as-built data.
Results to date for machines similar to the FNP turbine show increased energy for some disc fragments. As part of its investigation into disc cracking, Westinghouse nas estimated the probability of individual disc rupture at design conditions based on various inspection intervals for both existing and modified desi gns. Results of the calculations on existing Building Block 281 tat"ines indicate that the turbine failure probability I
assumed by Offshore Power Systems - remains appropriate for disc no. 2 at speeds up to design overspeed considering appropriate inspection intervals.
It is expected that this failure probability will be reduced by design improvements. These calculations ai sc indicate that the failure prob-abilities of discs nos. 3, 4 and 5 are substantially less than that for disc no. 2. Failure of disc no. I at speeds up to design overspeed does not result in a missile.
Reanalysis of the FNP turbine is planned during the final design process.
It is the judgment of Offshore Power Systems that when both the updated missile exit energy data and the disc rupture probability data are con-sidered, the probability of damaging a vital target will be no greater than that stated in testimony presently before the Board for the design over-speed case.
\\7 Calculations previously entered into evidence by both the Applicant and the Staff are based on an assumed alue of P (the probability of turbine missile generation) of 1 x 10-g/ year from the Bush Report.
3 <
None of the recently developed information affects the probability of occurrence of destructive overspeed.
Thus, there is no impact on the previous conclusion of Offshore Power Systems that the probability of damage to a vital target from a destructive overspeed missile is less than 10- per year, because the probability of failure of the overspeed protec-tion system is calculated to be on the order of 1 x 10-7 per demand. The Staff's analysis of destructive overspeed$ is based on a higher estimated probability of occurrence of destructive overspeed and there-fore includes consideration of the probability of striking a vital target, given a missile. The Staff analysis considers three targets.
In two cases (con-tainment and main steam piping) the staff's calculation of strike prob-ability depends cnly upon FNP geometry, i.e., it is assumed that a missile with the correct trajectory has adequate energy to reach the target.
In the third case (spent fuel pool) the calculated strike probability depends upon missile energy in addition to geometric factors. However, the energy dependence is such that increased missile exit energy will not result in
'ncreased strike probability.
As a result of the taregoing, it is concluded that recent observations of disc cracking, mis!,iie penetration tests and revised Westinghouse exit energy calculations will not adversely affect the conclusions put forth in prior testimony respecting the probability of unacceptable damage from a turbine missile.
YANKEE-ROWE DISC FAILURE On February 14, 1980, two discs in the low pressure unit of the Yankee-Rowe turbine generator failed with the turbine running at normal operating speed. The materials of the Yankee-Rowe turbine are similar to the Ship-pingport turbine, whose failure was addressed in prior testimony. Neither the Shippingport failure nor the Yankee-Rowe failure resulted in missile fonnation. Both machines failed from stress corrosion cracking after many years of service, and in neither case did the failed turbine receive periodic ultrasonic disc inservice inspection.
\\8_ Staff's written direct testimony, pp. 2-11.._
3 The failure at Yankee-Rowe does not alter the conclusion in testimony presently before the Board that the FNP turbine is not expected to experf-ence Shippingport-type failures.
Dated: November 20, 1981 e
D a
OPS-69 (12/4/81)
UNITED STATES OF AMERICA
. NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matt
)
)
0FFSHORE D(WER SYSTEMS
)
Docket No. STN 50-437
)
(Manufacturing License for
)
Floating Nuclear Power Plants)
)
APPLICANT'S TESTIMONY IN RESPONSE TO THE NOVEMBER 12, 1981 BOARD QUESTION NOS. 4-7 By letter dated November 12, 1981, the Applicant (Offshore Power Systems) and/or the NRC Staff were requested to submit written testimony in response to seven questions put by the Atomic Safety and Lkensing Board. The Applicant's responses to Questions 4 through 7 are presented infra.
Questions 1 through 3 are directed to the NRC Staff; therefore, the Applicant has not proffered '#ritten testimony in response to these questions.
e d
+ - - - - -
Question 4 What changes in the magnesium oxide core ladle would be necessary to provide complete containment of a molten core?
Is such a design feasible for the proposed floating nuclear plants?
Applicant's Response In 'rder for a postulated molten mixture of core debris and ladle material to be contained within the confines of the ladle, the heat flux at the pool boundary must not exceed that which can be conducted into the solid material ~ adjacent to the pool. The present core ladle would have to be enlarged to many. times its present size for passive cooling of the debris and for structural integrity of the core ladle support structure to be maintained. Because of space limitations, such enlargement is not feasible for the proposed floating nuclear plants.
Question 5 Explain in greater detail the differences between the density driven case and the Kulacki-Goldstein case for heat transfer in the mol ten pool.
Describe qualitatively the behavior at the interface between-the magnesium oxide and the molten uranium oxide in the core ladle, particularly at the bottom of the pool.
Discuss the possibility that pits will form in the pool bottom and grow preferentially.
Is the range of measurements de-scribed in the Kulacki-Goldstein paper appropriate to the situation in the molten core ladle?
Table 5 of SER Supplement 3 reflects that two of the analyzed sixteen cases show that the pool freezes.
Explain in qualitative terms why that happens.
Applicant's Response The following response addresses that part of Question 5 which is not specific to the NRC Staff's. analyses, i.e.,
the possibility that pits will form in the pool bottom and grow. preferentially. Mol ten material that preferentially penetrates into small cracks and pits which may develop in the ladle will tend to freeze and limit the extent of the penetration as heat is conducted out of these thin fins into the surrounding ladle material. The ladle construction using a staggered bricking pattern will also tend to prevent rapid selective penetration.
Question 6 Explain why convective heat transfer by air was not considered by the Staff in its thermal analysis of the molten pool. Following a core melt scenario, would there be any air exchange between the chamber of the core ladle and the balance of the containment?
Applicant's Response Some air exchange between the core ladle region and the balance of con-tainment would occur following a core melt accident; however, the Applicant (as well as the Staff) ignored convective heat transfer in the thermal analysis of the molten pool. Convective heat transfer during the first few days following a core melt accident represents a small fraction of the decay heat rate even with assumed high values of air flow rate and heat transfer coefficient. Neglecting convective heat transfer is conservative since it increases the heat that must be absorbed by the ladle.
Question 7 What changes would be required in the OPS design to meet the requirements of the proposed final rule on hydrogen control which, as modified by the Staf f at the Commission's request, is now being considered by the Comission?
Applicant's Response The Applicant understands 1/ that the NRC Staff is contemplating a require-ment that containments be able to accommodate inadvertent actuation of a post-accident CO inerting system.
Th..
requirement would be imposed 2
regardless of whether or not such a system is actually included in the plant design.
1/ The Applicant's understanding of the most recent proposed revision to the "Near-term CP/ML" hydrogen control rule is based on ' verbal dis-cussions with the NRC Staff. Since the proposed revision has not yet been sent to the Commission, copies were not available to the Applicant.
The Applicant has comitted in Amendnent 30 to the PDR to deugq the FNP containment to meet ' ASME Service Level A stress limits for an internal pressure of 25 psig which is sufficient to safely accommodate inadvertent actuation -of a post accident CO inerting system, should such a system 2
ultimately be installed in the FNP. Therefore, no changes in the FNP design are required to meet the requirements of the proposed final Near Term CP/ML rule on hydrogen control, as that rule is i.aderstood by the Applicant at this time.
Dated:
November 20, 1981.
Y _
OPS-67(12/4/81)
PROFESSIONAL QUALIFICATIONS OF BRIJ B. SETH My name is Brij B. Seth. My business address is Lester Branch G-205, Westinghouse Electric Corporation, P. O. Box 9175, Philadelphia, Pa.
19113.
I am currently Engineering Manager for the Low Pressure Disc Integrity Program.
In this position. I am responsible for engineering aspects of low pressure turbine disc integrity. This includes reliabil-ity assessments, diagnosis of disc cracking and short and long range improvements.
I was assigned to this position in February 1380.
From May 1979 to February 1380, I was Advisory Engineer in Service Engineering, Engineering Dept., Westinghouse Steam Turbine-Generator Division.
In this position I was responsible for developing an overall integrated p.~ogram on the corrosion aspects of turbine materials, designs and operations.
From Feb.1974 to May 1979, I held the position of' Manager, Materials Engineering, Engineering Dept., Westinghouse Steam Turbine Division.
In this capacity, I was responsible for all technical aspects of turbine material. This included defining research programs, managing materials development, supporting designers in the application of materials, develop-ing process specifications and materials procurement specifications, guid-ing failure analyses a1d providing materials support for the field work.
From Feb.1972 to Feb.1974, I held the position of Manager, Materials
- 'evelopment, Engin<:ering Dept., Westinghouse Steam Turbine Div.
In this position, I was responsible for initiating Research programs and guiding development work on turbine materials and processes.
l From May 1969 to Feb.1970, I held the position of Advisory Engineer in Metallurgy, Engineering Dept., Steam Turbine Division.
In this position, my r.;ponsibilities were to keep abreast of relevant technology areas in metallurgy and to advise Mgr. of Metallurgy on a wide variety of material problems.
Prior to joining Westinghouse, I had five years' experience with the Atlas Steels Company, Welland, Ort. Canada, where I was involved in research and development work to improve the quality of high speed tool, mining, hot work tool and stainless steels.
I earned the degree of Bachelor of Science from the Univet sity of Rajasthan, India in 1958, Bachelcr of Engineering (Metallurgy) from the Indian Institute of Science, Bangalore, India in 1960, and the degrees of Master of Applied Science (Met. Engrg.) and Doctor of Philosophy (Met. Engrg.),
from the University of Toronto, Canada in 1962 and 1964 respectively.
I am a member of the American Society of Metals and the Institute of Metallurgists.
I have published 24 papers on materials, properties and processing including three on low pressure turbine cracking.