ML20236A336
| ML20236A336 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee  |
| Issue date: | 03/01/1989 |
| From: | Curran D, Ferster A, Tousley D HARMON, CURRAN, SPIELBERG & EISENBERG, LLP., NEW ENGLAND COALITION ON NUCLEAR POLLUTION |
| To: | Atomic Safety and Licensing Board Panel |
| Shared Package | |
| ML20236A334 | List: |
| References | |
| OLA, NUDOCS 8903170087 | |
| Download: ML20236A336 (21) | |
Text
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. March 1,-1989 Chc .c l
UNITED STATES.0F AMERICA l NUCLEAR REGULATORY' COMMISSION. 1891 mR -7 P5 :25 i
BEFORE:THE: ATOMIC' SAFETY AND LICENSING BOARD
! 0FF Ki i '
W DOC H. i E A " W L-
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In the Matter of )
)
Vermont Yankee Nuclear )
Power Corporation ) Docket No. 50-271-OLA'
) _(Spent Fuel Pool)
(Vermont Yankee Nuclear; )
' Power Station)- )
)
NEW' ENGLAND COALITION ON NUCLEAR POLLUTION'S BRIEF.
AND
SUMMARY
-OF RELEVANT FACTS AND ARGUMENTS CN WHICH.
NECNP INTENDS TO' RELY.AT ORAL ARGUMENT ON CONTENTION 1 INTRODUCTION The purpose of the briefing and oral argument.provided for in.10 C.F.R.15'2.1113 is to dispose of any legal or undisputed factual issues and to designate' factual' disputes for an adjudicatory hearing.1 In this process, the licensee " bears the ultimate. burden of proof." Metropolitan Edison Co. '(Three Mile Island Nuclear Station, Unit' No. 2), ALAB-697, 16 NRC 1265,'1271 (1982). See also 10 C.F.R. 5 2.732, Lona Island Lichtina Co.
1- Subsection (b) of 5 2.1115 provides that:
No issue of law or fact shall be designated for resolution in an adjudicatory hearing unless the presiding officer determines that:
(1) There is a genuine and substantial dispute of fact which can only be resolved with sufficient accuracy by the introduction of evidence in an adjudicatory hearing; and (2) the decision of the Commission is likely to depend in
" whole or in part on the resolution of that dispute.
8903170087 ADDCK890301 05000271; PDR G PDRj
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' Summary of Proceedings
-On' April 28, 1986,- Vermont Yankee Nuclear Power Station- 1 (hereinafter Vermont- Yankee) filed an application' with the ~!
Nuclear' Regulatory Commission'(NRC) seeking a license amendment- j 1
to authorize increasing the storage capacity of its spent fuel j pool'from 2000 to 2870 spent fuel assemblies-by installing high j density racks. The New England Coalition on Nuclear Pollution (NECNP), sought permission to intervene, through the submission of contentions and information on standing.2 On May 26, 1987, this Board issued a prehearing conference order which, inter alia, admitted NECNP Contention 3, which stated as follows:
Contention 1 (Derivation: NECNP Contention 3)
The spent fuel pool expansion amendment should be j
-denied because, through the necessity to use one train of-
~
I the reactor's residual heat removal system (RHR) in addition l to the spent fuel pool cooling system in order to maintain- I the pool water within the regulatory limits of 140'F, the single failure criterion as set forth in the General Design Criteria, and particularly Criterion ~44, will be violated.
The Applicant has not established that its proposed method .q of spent fuel pool cooling ensures that both the fuel pool cooling system and the reactor cooling system are_ single failure proof.
LBP-87-17, 25 NRC 838 (1987). The Licensing Board's Order granted the parties 60 days of discovery on these contentions, and then 45 additional days of discovery following the NRC Staff's issuance of its Safety Evaluation Report (SER) and l
Environmental Assessment (EA).
I 2 Egg "NECNP's Response to Board Order of February 27, 1987:
Statement of Contentions and Standing," dated March 30, 1987.
j
Pursuant to the Board's order, NECNP propounded several sets of interrogatories to both the NRC Staff and the Applicant, on inter alia, whether the spent fuel pool cooling system at vermont Yankee meets the single failure criterion.
While these interrogatories were still outstanding, on June 10, 1987, the Applicant filed an interlocutory appeal of LBP 17. Although the Staff had originally opposed the admission of NECNP's single failure criterion contention, during the course of the Appeal, the Staff stated the following:
[T]he Staff's current review of the requested amendment revealed that the current Vermont Yankee Nuclear Power Sta-tion Technical Specifications (TS) do not ensure redundancy in the spent fuel pool cooling system. As a result of the Staff's review of the operation of the spent fuel pool cool- c ing system, and after discussions with the Staff, the Applicant agreed to submit a new TS that would obligate the Applicant to ensure redundant spent fuel pool cooling sys-tems.
"NRC Staff's Brief in Opposition to the Brief of Applicant,"
dated June 25, 1987, at 5, and Appendix C.3 The Appeal Board, with one minor change, affirmed the Licensing Board's admission of NECNP Contention 1 in ALAB-869, 26 NRC 17 (1987).
3 The NRC Staff subsequently filed responses to NECNP's inter-rogatories, which stated the Staff's position that the Vermont Yankee spent fuel pool cooling system does not have sufficient capacity to cool the normal spent fuel heat load and maintain pool water temperature below 140'F in the event of a single failure, although redundancy of spent fuel pool cooling was required by General Design Criteria 44. See NRC Staff Response to NECNP's First Set of Interrogatories and Document Request to the NRC Staff, dated August 5, 1987, at 6-7. However, the NRC failed to respond to NECNP's Third Set of Interrogatories and Document Requests to the NRC Staff, dated July 21, 1987, which inquired further into the NRC Staff's new position that Vermont Yankee's current technical specification did not ensure sufficient redundency in the spent fuel pool cooling system.
2
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Consistent with the representations made in the NRC Staff's brief to the Appeal Board, the NRC Staff held a meeting with Ver-mont Yankee on February 9, 1988, at which point Vermont Yankee committed to design, install, t.est and make operational a redundant, seismically designed spent fuel pool cooling system prior to the time Vermont Yankee exceeds the existing 2,000 spent fuel assembly storage limits in the Vermont Yankee spent fuel pool.4 At that meeting, Vermont Yankee representatives-described a " proposed schedule" (Tr. 19-20) for completion of the
" conceptual design," the " detailed design," and installation of the system as follows: completion of the " conceptual design" by the end of " Cycle 14" (projected for September, 1990); completion of the " detailed design," the enu of Cycle 15, (projected for April, 1992); and " installation of the entire design change . . .
such that it is complete and fully operational at the end of Cycle 16" (projected for October, 1993).
On March 2, 1988, Vermont Yankee submitted a letter, generally describing "the design and performance criteria for the enhanced Vermont Yankee Spent Fuel Pool Cooling System," and responding to some questions posed by the NRC at the February 9, l 1988 meeting. On June 7, 1988, Vermont Yankee submitted a " des-cription of the enhanced Spent Fuel Pool Cooling System in the format of a revised Final Safety Analysis Report (FSAR)," and l
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4 See Memorandum to NRC Document Control Desk from Warren Mur-phy, Vermont Yankee, dated March 2, 1988 (FVY 88-17), at 1. l
L a.
.further stated that "[t]he design, installation and testing of l the-enhanced system.will be in accordance with 10 CFR 50.59.n5 On the basis of these'two submissions, counsel for Vermont Yankee requested, at the June 28, 1988 prehearing conference, that the Licensing Board rule that these submissions'" mooted" NECNP Contention 1. The Licensing Board rejected this request in ;
its Second Prehearing Order, stating that "[t]he Board rejected the Applicant's claim that the contention had become moot as a' ,
result of the filing of an FSAR. amendment (on June 7, 1988)-
incorporating a revised fuel pool cooling system, on the basis that the question whether the revised system was capable of per-forming as specified was still open."6 The Licensing Board then granted 60 days additional discovery, with discovery against the Staff awaiting issuance'of the Staff's SER.7 l l
NECNP was unable, through its discovery requests, to obtain any more detailed design information from Vermont Yankee regard-l 5 Letter to NRC from Warren Murphy, Vermont Yankee (FVY 88-47),
dated June 7, 1988, at 2. The proposed enhancement to the Ver-mont Yankee spent fuel pool cooling system consists of the addition of a seismically qualified Emergency Standby Sub-system, in addition to the nonseismic, normal spent fuel pool cooling subsystem. According to the Applicant's June 7, 1988, conceptual proposal, . the, emergency standby subsystem will have two pumps (one in each train) running concurrently to cool the pool with 2870 spent fuel assemblies, in the event of a full core discharge heat load. This emergency standby subsystem would be used in the event an unusually high spent fuel decay 3 heat load is placed in the pool, or in the event of a seismic l event, to maintain pool temperatures within the design limits with the increased heat load from the addition of 870 spent l.
l fuel assemblies to the spent fuel pool's storage capacity.
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- T ing its proposed enhanced spent. fuel pool' cooling system.8 . Fur-thermore, Vermont' Yankee stated.that it had no schedule for 3 implementing its conception and Vermont Yankee would not undertake the preparation of "the detailed design (as distinct from'the conceptional' design, which has already been accomplished)," since " Vermont Yankee's' final determination to-undertake this project is also dependent upon resolution of these:
proceedings, issuance of the proposed license amendment, and issuance by the NRC Staff of an SER concluding that the project resolves all outstanding issues and concern relevant to.the ade-quacy of the VYNPS spent fuel pool cooling system."9 The Staff SER was not issued until October 14, 1988. It contained no evaluation of whether the existing Vermont Yankee spent' fuel pool cooling system satisfied the single failure criterion. Instead, the SER evaluated the conceptual proposal for the enhanced spent fuel pool cooling' system described in Ver-mont Yankee's March 2, and June 7, 1988 letters, and concluded
, that:
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[T]he Vermont Yankee high density racks and fuel pool, including enhanced spent fuel pool cooling, is acceptable for the proposed expansion to 2870 assemblies, provided that the number of spent fuel assemblies does not exceed 2000 until the enhanced system as~ described in the licensee's June 7, 1988 submittal has been installed and tested to demonstrate operability.
8 See " Answers of Vermont Yankee to NECNP's Third Set of Inter-rogatories and Requests for the Production of Documents,"
dated August 16, 1988.
9 " Vermont Yankee's Further Answers to Interrogatories," dated October 7, 1988, at 2.
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'IUtC Staff SER,. dated October 14, 1988g at 38.
Following issuance:of the Staff SER, NECNP propounded two
, r sets of interrogatories attempting to. discover the basis for-the a 'NRC Staff's conclusions and evaluation contained in the SER, par - ;
-ticularly regarding the enhanced spent fuel pool cooling sys- ,
tem.10 Based on the NRC Staff's responses, it was apparent that Vermont Yankee's " conceptual proposal" for the enhanced spent:
fuel pool cooling system, as described in the March 2, and June 7, 1988 Vermont Yankee submittals, was the sole basis for the conclusions and evaluations contained in the SER.11 Moreover, the Staff indicated.that it considered no further design-details, j to be necessary for its review of whether the enhancement meets the single failure criterion.12
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~ o I l 10 See NECNP's First and Second Sets of Interrogatories and l Requests for Production.of Documents to the NRC Staff on the Staff's Spent Fuel Pool Expansion Safety Evaluation, dated i l October 31, 1988 and January 17, 1989, respectively, j 11 Seg NRC Staff Response to NECNP's First Set of Interrogatories I and Request for Production of Documents to the NRC Staff on the Staff's Spent Fuel Pool Expansion Safety Evaluation, dated December 27, 1988, at 4-6 (Responses to NECNP Interrogatory 4 )', and NRC Staff Response to NECNP's Second Set of Inter-L rogatories and Request for Production of Documents to the NRC J. Staff on the Staff's Spent Fuel Pool Expansion Safety Evalua- l tion, dated January 31, 1989, at 2-4 (Responses to NECNP Interrogatory 2).
12 NRC Staff Response to NECNP's Second Set of Interrogatories and Request for Production of Documents to the NRC Staff on 1 E the Staff's Spent Fuel Pool Expansion Safety Evaluation, dated January 31, 1989, at 4-6 (Responses to NECNP Interrogatory 3).
. '1 Description of Vermont Yankee Scent Fuel' Pool Coolina System The Vermont Yankee Nuclear Power Station ( Vermont Yankee")
includes in its design a pool for theistorage of spent fuel l l
assemblies. The spent fuel pool provides for storage, shielding, -
and cooling of spent fuel. The pool:is at an elevated location i
'in the reactor building (secondary containment), adjacent to the q primary containment.and exposed to the refueling deck atmosphere.
The spent fuel pool is a reinforced concrete structure supported.
p .by the reactor building walls. The pool is approximately 26 feet' wide by 40 feet long.by 39 feet high, and is' lined with stainless steel to provide leakage protection. . Spent fuel is stored'in the pool in free standing racks which are supported by the spent fuel
- pool floor.13 Decay heat removal from the spent fuel pool is a safety-related function. If the decay heat removal function fails, the integrity of the spent fuel cladding cannot be maintained, and a radiological release from:the damaged spent fuel assemblies can occur. For example, as set forth in NRC Regulatory Guide 1.13, Spent Fuel Storace Facility Desian Basis, Revision 1, December 1975, at page 1.13-1, "[u]nless protective measures are taken, loss of water from a fuel storage pool could cause overheating of the spent fuel and resultant damage to fuel cladding integrity and could result in release of radioactive materials to the environment."14
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13 Bridenbaugh/Sholly Affidavit at par. 7.
14 191. , par. 9.
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l This is true both generally for BWR Mark I plants, and for Vermont Yankee specifically, as recognized in the updated FSAR.
At Vermont Yankee, the spent fuel pool is cooled by the Spent Fuel Pool Cooling System (SFPCS). According to the Vermont ;
Yankee Updated FSAR, the " safety objective" of the SFPCS is to maintain fuel pool water at a temperature which will prevent damage to the fuel elements. Accordingly, the SFPCS at Vermont Yankee is safety-related.15 l The Vermont Yankee SFPCS consists of two identical trains of equipment. Each train includes one 450 gpm 16 centrifugal pump, and one 2.23 MBtu 17/ hour tube-and-shell heat exchanger.18 The ,
two trains of the SFPCS are headered together on the suction side 1
of the pumps and at the discharge of the heat exchangers. The i
SFPCS is a non-seismic Category I, non-Class IE system. The !
1 SFPCS cools the spent fuel pool by transferring decay heat from j l
the spent fuel assemblies to the water in the pool and sub- )
l 15 Id., par. 10.
16 Gallons per minute.
17 Million British thermal units.
18 The heat removal capability of one train of the Spent Fuel Pool Cooling System is 2.23 MBtu/Hr according to the plant j updated FSAR. For the proposed 2,870 fuel assembly limit on pool size, the NRC Staff estimates that the normal heat gener- l ation rate is 10.1 MBtu/Hr, and the abnormal heat generation I rate (for a full core offload) is 21.46 MBtu/Hr. These heat generation rates are well in excess of the capabilities of both trains of the SFPCS. Even assuming that the pool size remains at 2,000 assemblies, the conclusion that the SFPCS is l inadequate to remove the pool decay heat remains viable.
Bridenbaugh/Sholly Affidavit at par. 11, note 10.
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sequently by pumping the pool water through heat exchangers to the reactor building closed cooling water system (RBCCWS). Heat from the RBCCWS is rejected to the ultimate heat sink via the residual heat removal service water system. The spent fuel pool is filled by, and makeup to the pool is supplied from, the con-densate transfer system. The SFPCS pumps and heat exchangers are qualified for a temperature of 150*F.19 The residual heat removal (RHR) system can be used to sup-plement SFPCS capacity when necessary. Connections are provided on the shutdown cooling piping portion of the RHR system for making a connection to the fuel pool system for this purpose. In addition, the two loops of RHR are cross-connected by a single header, making it possible to supply either loop of RHR by pumps in either loop.20 ARGUMENT I. THE SINGLE FAILURE CRITERION APPLIES TO SPENT FUEL POOL COOLING.
(
In the early stages of this proceeding, the Applicant I attempted to exclude this contention on the ground that the single failure criterion is not applicable to spent fuel cooling systems. See Brief of Applicant on Appeal Pursuant to 10 C.F.R. 5 2.714a From a Prehearing Conference Order, LBP-87-17, Issued May 26, 1987, dated June 10, 1987 (hereafter " Applicant's Appeal 19 Bridenbaugh/Sholly Affidavit at par. 11.
20 Id., par. 12.
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i l Brief of June 10, 1987"), at 19. The Licensing Board, with the' j f
L approval'of the Appeal Board, rejected Applicant's arguments and 1 reserved disposition of this ' issue for the briefing and' argument. !
on the. merits. Prehearing Conference Order, LBP-87-17, . 25: NRC f f
838, 849 (1987) ; - ALAB-869, 26 NRC 13,.22-24 (1987). Thus, NECNP addresses Applicant's arguments herein.
The single failure criterion is made applicable to nuclear. )
l power plant fluid systems through General Design Criterion 44, j
.)
which requires that: !
A system to transfer heat from structures, systems, and )
components important to safety, to an ultimate heat !
sink shall'be provided. The system safety function ,
shall be to transfer the combined heat load of these j structures, systems, and components under normal opera- j ting and accident conditions.
Suitable redundancy in components and features, and suitable interconnections, leak detection, and iso 1 lation capabilities shall be provided to assure that i i
for onsite electric power system operation (assuming offsite power is not available) and for offsite elec-tric power system operation (assuming onsite power is .
I not available) the system safety function can be accomplished, assuming a single failure.
There can be no question that the cooling of the fuel rods in the spent fuel pool is a safety-function. See Sholly/Bridenbaugh ]
Affidavit at par. 9. The Staff has historically applied the single failure criterion to spent fuel cooling systems, including Vermont Yankee's. Standard Review Plan, Section 9.1.3.
The Applicant has challenged this longstanding NRC Staff interpretation of the general design criteria with a cramped and illogical reading of the GDC.21 Applicant contends that if the 21 Een Applicant's Appeal Brief of June 10, 1987, at 19. l I
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NRC had intended-to' apply the single failure. criterion to spent-
. fuel pools,.it would have specifically said so in'GDC 61,'which
! addresses,' inter alia, heat removal for spent fuel pools.22 GDC 61's.brief' reference to heat removal is found in subsection (4),
l which requires " residual heat removal capability having reliability and testability that reflects the'importance to safety of decay heat and other residual heat removal." This gen-eral language sets no standard that is different from or inconsistent with that of GDC 44. To the contrary, it requires a reference to GDC.44 for a determination of the nature and degree of " reliability" that is required for residual heat removal sys-tems that.are important to safety. Contrary to Applicant's argu-ment, GDC 61 and GDC 44 are mutually consistent.23 l
22 GDC 61 provides as follows:
Fuel storage and handling and radioactivity control. The fuel storage and handling, radioactive waste, and other systems'which may contain radioactivity shall be designed-to assure adequate safety under' normal and postulated acci-
, dent conditions. These systems shall be designated (1) l with a capability to permit appropriate periodic inspection i and testing of components important to safety, (2) with suitable shielding for radiation protection, (3) with appropriate containment, confinement, and filtering sys-tems, (4) with a residual heat removal capability having reliability and testability that reflects the importance to safety of decay heat'and other residual heat removal, and
, (5) to prevent significant' reduction in fuel storage
! coolant inventory under accident conditions.
23 The Applicant also attached great significance to the fact that while GDC 44 falls under a heading entitled " Fluid Sys-l tems," GDC 61 is included under a heading entitled " Fuel and Radioactivity Control." Id. Applicant cited no reason to believe that these general headings were meant to convey mutual exclusivity. The spent fuel pool cooling system is clearly a " fluid system," and therefore subject to the requirements for such systems.
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The. Applicant has'also' argued that " insofar as NECNP's con-tention raised the single failure criterion vis-a-vis the spent fuel pool cooling system, it' raised only.the failure of passive components because the active components are redundant."24 According to the Applicant, the single failure criterion does not apply to' passive failures in fluid systems. See Appendix A, Definitions and Explanations, note 1.25 This argument is also without' merit. Regardless of whether or not they are redundant, the active components of the Vermont Yankee spent fuel pool cooling system, including SFPCS pumps and RHR pumps, are not. single failure proof.26 See discussion below at section II.B, Bridenbaugh/Sholly Affidavit at section C.
Thus, active rather than passive failures are at issue here.
~II. THE EXISTING VERMONT YANKEE SFPCS DOES NOT SATISFY THE SINGLE FAILURE CRITERION.
A. The Vermont Yankee'SFPCS does not have sufficient capacity to cool the normal' spent fuel discharge heat load and maintain pool temperature below the design limit of 150*F.
The Vermont Yankue spent fuel pool and its cooling system were originally designed to accommodate 600 spent fuel assum- >
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24 Applicant's Appeal Brief of June 10, 1987, at 19.
25 It should be noted that the conditions under which passive failures should be considered have been "under development" for all of eighteen years.
26 It should also be noted that neither Applicant nor Staff has identified all of the active failures that should be consid-ered in evaluating whether the spent fuel cooling system is single failure proof. See Bridenbaugh/Sholly Affidavit, pars.
19-20.
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blies. The presently' contemplated amendment would increase that p number to 2870 assemblies.,,a'378% increase over the original L design. Both Applicant 27 and' Staff 28 have conceded'in the course of this proceeding that the existing Vermont Yankee Spent Fuel
. Pool Cooling System with the newly contemplated number of assem-blies'is not single failure proof (has insufficient heat carrying.
l capacity) until between 42 and 69 days following a normal one-l-
third. core fuel discharge.29 This is because it would'take that long following a normal refueling' discharge (1/3 core offload) for the heat level of the freshly discharged fuel, together with the spent fuel already in the pool, to decay to the' point that the pool temperature could be kept below the design limit of 150*F by one train (1 pump and 1 heat exchanger) of the existing Spent Fuel Pool Cooling System
-(SFPCS).30 The Staff has not prepared a safety evaluation which evaluates the heat removal capability or single failure criterion 127 See Vermont Yankee's November 24, 1986 Response to NRC Staff October 22, 1986 Question 17 (" Vermont Yankee does not con-sider the Fuel Pool Cooling System to be single active failure proof (depending on RBCCW temp) until after approximately 42 days decay of a normal spent fuel discharge."), attached as Exhibit A to this brief.
28 .NRC Staff Response to NECNP's First Set of Interrogatories, August 5, 1987, Response to Interrogatories 32 and 34.
29 Forty-two days would be the applicable period with 2000 spent fuel assemblies in the pool, and 69 days would apply with 2870 assemblies in the pool. November 10, 1988 Memorandum of Ver-
.mont Yankee Nuclear Power Corporation in Response to Memorandum and Order of 10/24/88, at 4.
30 Sea Bridenbaugh/Sholly Affidavit at par. 16.
compliance of the existing Vermont Yankee SFPCS.31 Remarkably, the NRC Staff now appears to have reversed its earlier position that the existing system is inadequate, notwithstanding its fail-ure to even address the issue in its SER. As discussed below, NECNP continues to contend that the existing SFPCS does not satisfy the single failure criterion.
B. Applicant Defines the "Most Critical Single Active Failure" Incorrectly.
In reaching its conclusion that the existing SFPCS satisfies the single failure criterion, Applicant assumes that the most critical single active failure would involve the lo's s of one SFPCS pump, with one pump and both heat exchangers remaining in operation.32 On several different grounds, this assumption is incorrect.
- 1. There are Single Active Failures That Would Result in the Availability of Only One Pump and One Heat Exchanger As is explained and attested to in the attached affidavit of Dale G. Bridenbaugh and Steven C. Sholly, there are several identifiable single active failures for Vermont Yankee which 31 The Staff has evaluated the Applicant's proposed enhancement in an SER dated October 14, 1988. Attachment 8 to Briden-baugh/Sholly Affidavit. The SER includes no discussion what-soever of whether the existina system mysts the single failure criterion. In fact, apparently based on the Applicant's com-mitment to install the enhanced system, the Staff never pro-vided NECNP with complete answers to its interrogatories regarding the ability of the existing system to satisfy the single failure criterion. See note 3, suora.
32 Bridenbaugh/Sholly Affidavit at par. 17.
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, would result in only one pump and one heat exchanger of the SFPCS being available.33 They provide two examples:
(a) failure of one train of safety-related AC power (due, for example, to failure of a diesel generator to start, failure of a diesel generator to continue to run once started, failure of safety-related switchgear to pick up the load, or unavailability of a diesel generator due to maintenance or surveillance testing), or (b) failure of one train of safety-related DC power (due, for example,Lto fail-ure of a battery charger, unavailability of a DC battery due to maintenance or surveillance testing, or failure of a DC battery due to maintenance error)'.34 Messrs. Bridenbaugh and Sholly go on to explain: ,
Under these failure conditions, c'nly one train of cervice water will be available. Thus, the fact that the SFPCS heat exchangers can be cross-connected is largely irrelevant since one of the two SFPCS heat exchangers will not have water flowing past the secondary side of the heat exchanger to serve as a mechanism for heat transfer across the heat exchanger tubes.35 Thus, without even considering the effect of seismic consid-erations on the single failure analysis (see infra), it is clear that the most critical single active failure for the existing Vermont Yankee SFPCS would result in the availability of only one H SFPCS pump and one heat exchanger to cool the spent fuel pool.36 This circumstance would clearly require a much greater reliance on the RHR system for backup to cool the spent fuel pool, thus compromising the RHR system's safety function for the reactor.37 l
33 Id., pars. 18-19.
34 Id , Par. 19.
35 74, 36 Id., par. 23.
37 Id., pars. 13-14.
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2.- The Most Critical Single Active Failure for'Ver-mont Yankee Would. Result in the Availability.of Only One Train of the RHR System.for Spent Fuel
!s Pool Cooling and Reactor Cooling. t
-As the Bridenbaugh/Sholly Affidavit attests, since none of the existing Vermont' Yankee SFPCS.is seismic Category.I38, the entire system--both pumps, both. heat exchangers,.and both service water systems--must be assumed to be unavailable'following a safe shutdown earthquake.39 Clearly, the safe shutdown. earthquake 1 f
(SSE) would constitute'the limiting failure'for the. Vermont Yankee SFPCS. Since the' entire SFPCS must be assumed'to be unavailable following an SSE,. reliance"on-one train of the reac-tor's Residual Heat' Removal (RHR) system would be necessary.to remove decay heat from the spent fuel pool.40 Since the SSE is assumed to be accompanied by a single fail-ure, one train of the RHR system must be assumed to be unavail-able, as well. That leaves only'the remaining train of RHR to cool both'the reactor and the spent fuel pool.41 The NRC Sta'ff has determined that using one train of RHR to' switch between cooling the spent' fuel pool and cooling the reactor is not
- appropriate since too many operator actions and RHR pump starts are required to operate in this mode.42 38 Both Applicant and Staff have conceded that the Vermont Yankee SFPCS is not seismically qualified. See Bridenbaugh/Sholly Affidavit at par. 20, note 18. -
39 Bridenbaugh/Sholly Affidavit at pars. 20, 24.
40 Id., par. 20.
41 yg,
- 42 yg,
The difficulties inherent.in such a-mode of operation
'(switching the single available RHR between the reactor'and the spent fuel pool) are' exacerbated by the proposed amendment, since the heat removal needsLof the spent fuel-pool will-be greater with 2870' assemblies than~with 2000. Thus,-the RHR would have to-be devoted to spent fuel pool cooling a greater proportion.of thel time, and would be correspondingly less available to serve its reactor cooling. function.43 The Bridenbaugh/Sholly Affidavit also points _out that the spent fuel pool makeup water is provided by the non-seismically qualified condensate system, and so cannot be assumed to be available following an SSE.44 Messrs. Bridenbaugh and Sholly further explain that the proposed alternative sources of makeup water are'also not seismically qualified, and thus do not meet the single failure criterion.45 Moreover, the existing SFPCS is not safety class IE, which provides an additional basis for concluding that the SFPCS is not single failure proof.46 Thus, when the "most critical single active failure" is properly defined, it is beyond question that the existing Vermont Yankee SFPCS cannot satisfy the single failure criterion. As Messrs. Bridenbaugh and Sholly conclude:
43 Jd., par. 20.
44 Id., pars. 21-22.
45 74, 46 Id., par. 24 and note 23.
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-[T]heLlicensee~isLincorrect that "Given the most critcal-
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' single-activeLfailure,.therefore, the configuration.of the
.: system is'one pump and two heat e.xchangers." In-fact, given.
the most critical, single active failure,'the configuration of the1 Vermont Yankee.SFPCS is no pumps or' heat exchangers' l for-SSE conditions,.andLone pump and.one heat exchanger otherwise.47 l With no-SFPCS pumps or heat exchangers, and only one RHR' train available for.both 1the. reactor and the spent fuel pool after a Safe Shutdown Earthquake, the single failure criterion is' not met. ~This condition violates GDC-2 and GDC-44. With one pump and one. heat exchanger from the SFPCS available, the single failure criterion'is violated for at least 69 days following a.
normal refueling.1/3 core offload. g CONCLUSION I
For the foregoing reasons, this Board must conclude that .;
Vermont Yankee's existing spent fuel pool cooling system does not j satisfy the single failure criteria, and that there is insuffi- J cient information to support a finding that Vermont Yankee's pro-posed enhancement to its existing spent fuel pool cooling system i
would bring the facility into compliance with this requirement. J Respectfully submitt
" f- _-
drea C. Ferster Diane Curran Dean R. Tousley Dated: March 1, 1989 47 Id., par. 23.
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... . . . . . . ;_.......__ . . . . . . . . _ . . . . . . . . EXHIBIT A
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-f i ERMONT YANKEE
UCLEAR POWE'R CORPORATION
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RD 5. Bos 169, Ferry Road. Brattleboro,VT 05301 ,
y ENGINEERING OFFICE 1871 WORCESTER ROAD e FR AMINGHAM. M ASS ACHUSETTS 01701 e TEkspacent sit.snesco
. Nove=ber 24, 1986 *"
EYY 86-107 United States Wuclear Regulatory Commission Washington, DC 20555 Attention: Office of Wuclear Reactor Regulation Mr.' Vernon L. Rooney BWR Project Directorate No. 2 Division of BWR Licensint,
References:
(a) License No. DPR-28 (Docket No. 50-271)
(b) Letter VYNPC to USNRC, m 86-34, " Proposed Yechnical Specification. Change for Spent and New Puel Storage,"
dated April 25, 1986 (c) Letter USNRC to VYNPC. EYY 86-147o dated July 24, 1986 (d) Letter..VYNPC to USNRC, m 86-73, dated August 15, 1985 j.7q. (e) Letter VYNPC to USERC, m 86-88, dated Septe=ber 26, 1986
- (f) Letter, VYNPC to USERC, M 86-98, dated October 21, 1986 (g) Letter, USERC to VYNPC, EVY 86-217, dated October 22, 1986
Subject:
Response to Request for Additional Infor: ation - Proposed Change No. 133. Spent Puel Pool Expansien Paar Sir:
By letter, dated october 22, 1986 [ Reference (g)), you requested Vermont
! Yankee provide additional information in order for you to co:::plete your review of the proposed spent fuel pool expansion technical specification change submitted April 25, 1986 [ Reference (b)]. Accordingly, Enclosure i provides responses to each of the 31 questions transmitted with your October 22, 1986 lettar.
We trust that the enclosed is responsive to your request; however, should you have any questions or require further information regarding this v.atter, please contact this office. .
Very truly yours.
VERMONT YANKEE NUC}E POWER CORPORATIVE
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R. W. Caps ick
.- Licensing Engineer
- [ % RWC/bil Enclosure ,
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w Question 17: Provide a discussion as to the design features of th criterion with the spent fuel storage facility filled with normal refueling"and maintaining the pool water temperature at less than 140 F.
Response _:
i f RHR augmented fuel pool cooling requires the corm:itment of one tra n RER consisting of 2 W .
fuel pool cooling is single active failure proof.
l pool cooling As stated in the response to Question Number 13, l the spent fue to remove system is not re11ed on until sufficient decay has taken h 150 F p aceBoth trains of fuel p RHR from augmented fuel pool cooling service.
back-up.
Tech Spec limit and RER augmented Puel can pcni cooling the fuel pool cooling hW ave diverse power supplies l Cooling so one pu::pBecaus System be relied on at all times.and RHR backup, Ve_rmont ) until Yankee does not conside after Historically tgsingle ac_ tive_ fa'ilure' proof (depending on R50CW te::p approxicafely 42 days decay of a normal spent fuel discharge. days from shutdo normal refueling at Verrent Yankee has taken longer than 42 i
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