ML20138L390
| ML20138L390 | |
| Person / Time | |
|---|---|
| Site: | Peach Bottom  |
| Issue date: | 12/03/1985 |
| From: | Muller D Office of Nuclear Reactor Regulation |
| To: | |
| Shared Package | |
| ML20138L395 | List: |
| References | |
| NUDOCS 8512190259 | |
| Download: ML20138L390 (18) | |
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7590-01 UNITED STATES NUCLEAR REGULATORY COMMISSION PHILADELPHIA ELECTRIC COMPANY, ET AL.
00CKETS NOS. 50-277 AND 50-278 NOTICE OF CONSIDERATION OF ISSUANCE OF AMENDMENTS TO FACILITY OPERATING LICENSES AND PROPOSED NO SIGNIFICANT HAZARDS CONSIDERATION DETERMINATION AND OPPORTUNITY FOR HEARING The U.S. Nuclear Regulatory Consnission (the Conrnission) is considering issuance of amendments to Facility Operating Licenses Nos. DPR-44 and DPR-56 issued to Philadelphia Electric Company, Public Service Electric and Gas Company, Delmarva Power and Light Company and Atlantic City Electric Company (the licensees), for operation of the Peach Bottom Atomic Power Station, Units Nos. 2 and 3 (the facility), located in York County, Pennsylvania.
The amendments would authorize the licensees to increase the storage capacity of the spent fuel pool from the present capacity of 2,608 storage cells to 3,819 storage cells for each unit. The change would be accomplished by the installation of high density fuel rack modales with center to center clearances between cells of 6.28 inches compared to the current design of 7.0 inches, a slight reduction in wall thickness ci each cell and closer placement of cell racks to the pool walls of approximately one foot versus the current 2 1/2 feet design. The racks would utilize a neutron absorbing material bitween cells to assure a subcritical configuration. To provide more room for storage racks, the licensees also propose to remove some of the pool floor swing bolts (no longer functional) to avoid interference with the support feet on the new racks.
In order to provide additional floor space for new 8512190259 851203 PDR ADOCK 05000277 p
PDR k-l m
. storage racks, the end sections and diffusers of the spent fuel pool cooling discharge pipe will he removed. The licensees' request for approval of the new spent fuel storage racks is provided in a letter dated June 13, 1985, as supplemented by letters dated August 1,1985, and October 9,1985.
Before issuance of the proposed license amendments granting approval of the new spent fuel storage racks, the Commission will have made findings required by the Atomic Energy Act of 1954, as amended (the Act) and the Comission's regulations.
The Commission has made a proposed determination that the license amendments required by this approval involve no significant hazards consideration.
Under the Comission's regulations in 10 CFR 950.92, this means that operation of the facility in accordance with the proposed amendments would not (1) involve a significant increase in the probability or consequences of an accident previously evaluated; or (2) create the possibility of a new or different kind of accident from any accident previously evaluated; or (3) involve a significant reduction in a margin of safety.
The Commission has provided guidance concerning the application of these standards by providing examples of amendments considered likely, and not likely, to involve a significant hazards consideration. These were published in the FEDERAL REGISTER on April 6, 1983 (48 FR 14870). Spent fuel pool reracking was specifically excluded from the list of examples considered likely to involve a significant hazards consideration.
Pending further study of this matter, the Comission is making a finding on the question of no significant hazards consideration for each reracking application such as this on a case-by-case basis, giving full consideration to the technical circumstances of the case, using the standards of 10 CFR 550.92 (48 FR 14869).
. The technical evaluation of whether or not an increased spent fuel pool storage capacity by reracking involves sitjnificart hazards considerations is centered on three standards:
(1) Does increasing the spent fuel pool storage capacity significantly increase the probability or consequences of accidents previously evaluated? Reracking to allow closer spacing of fuel assemblies does not significantly increase the probability or consequences of accidents previously analyzed.
(2) Does increasing the spent fuel pool storage capacity create the possibility of a new or different kind of accident from any accident previously evaluated? With respect to Peach Bottom Atomic Power Station, Units 2 and 3, the Commission's staff has not identified any new categories or kinds of accidents as a result of reracking to allow closer spacing for the fuel assemblies. The proposed reracking does not create the possibility of a new or different kind of accident for the spent fuel pool.
In all reracking reviews completed to date, all credible accidents postulated have been found to be conservatively bounded by the evaluations cited in the Safety Evaluation (SEs) supporting each arendment.
(3) Does increasing the spent fuel pool storage capacity significantly reduce a margin of safety?
The Commission's staff has not identified significant reductions in safety margins due to increasing the storage capacity of the spent fuel pool by reracking. The expansion results in an increased heat load, but this heat load increase is generally well within the design limitations of the installed cooling systems.
In some cases, it may be necessary to increase the heat removal capacity by relat'.vely minor changes in the cooling system, i.e., by l
l h....
4 increasing a pump capacity. But in all cases, the temperature of the pool-will remain below design valuest The small' increase in the' total amount of-
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fission products in the pool is not a significant factor in accident considerations.
The increased storage capacity may result in an increase in the pool reactivity as measured by the neutron multiplication factor (K,ff). However, after extensive study, the Commission's staff determined in 1976 that as long as the maximum neutron multiplication factor was less than or equal to 0.95, then any change in the pool reactivity would not significantly reduce the margin of safety regardless of the storage capacity of the pool. The. licensees have
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indicated that the K,ff would not exceed 0.95.
The techniques utilized to calculate K have been bench-marked against experimental data and are eff considered very reliable by the staff.
Reracking to allow a closer spacing between fuel assemblies can be done by proven technologies.
In suninary, replacing existing racks with a design which allows closer spacing between stored spent fuel assemblies is considered not likely to involve significant hazards considerations if two conditions are met.
- First, no new technology or unproven technology may be utilized in either the construction process or in the analytical technioues necessary to justify expansion. Second, the K,ff of the pool must be maintained less than or equal to 0.95.
Reracking to allow closer spacing at Peach Bottom satisfies s
these conditions.
9 The licensees have stated that their analysis of the proposed reracking was accomplished using currently acceptable codes and standards and conforms.
to Commission staff guidance of April 1978. The technical evaluation of whether'or not an increased spent fuel pool storage capacity involves significant hazards consideration is centered on three standards:
First Standard Involve a significant increase in the probability or consequences of an accident previously evaluated.
In the course of the analysis, the licensees identified the following potential accident scenarios in Chapters 3, 4 and 5 of their submittal.
'1.
A spent fuel assembly drop in the spent fuel pool 2.
Loss of spent fuel pool cooling system flow 3.
A seismic event 4.
A spent fuel cask drop 5.
Criticality accident 6.
Load handling accident The probability of the occurrence of any o' the first four accidents is not affected by the racks themselves; thus, rerac' king cannot increase the probability of these accidents.
The consequences of a spent fuel assembly drop in the spent fuel pool are discussed in the licensees' submittal.
For this accident condition, the criticality acceptance criterion is not violated (Section 4.6.3).
The r
e-
4 radiological consequences of a fuel assembly drop are not changed from the previous Peach Bottom reracking analysis.
The results of the Commission staff's evaluation were transmitted to the licensees on November 30, 1978.
The licensees' analysis of the reracked design indicates a droppt' fuel assembly would not violate the criticality acceptance t.*iteria and the spent fuel pool liner would not be perforated. Thus, the consequences of this kind of accident will not be significantly increased from previously evaluated spent fuel assembly drops, which have been found to be acceptable by the Commission.
The consequences of loss of spent fuel pool cooling system flow have 1
been evaluated for the existing spent fuel pool cooling system design as described in the licensees' submittal (Section 3.4.3).
There are three spent fuel pool cooling system pumps and heat exchanger trains. The current cooling system design will provide sufficient cooling capacity for the proposed reracking. The structural integrity of the spent fuel pool will be maintained and no new means of losing cooling water or flow have been identified. Thus, the consequences of this type accident will not be significantly increased from previously evaluated' loss of cooling system flow accidents.
The consequences of a seismic event have been evaluated. The new racks will be designed and fabricated to satisfy the Commission's accepted design criteria. The racks are designed to Seismic Category I criteria. The racks are neither anchored to the pool floor nor are they attached to the pool side walls. The racks are structurally adequate to resist normal and accident
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load combinations. The racks are designed so that the floor loading from the racks filled with spent fuel assemblies does not exceed the structural capacity of the auxiliary building. Therefore, the integrity of the pool will be maintained and no new means of losing cooling water or flow have been identified. Thus, the consequences of a seismic event will not be significantly increased from previously evaluated events.
The consequences of a spent fuel cask drop accident are unchanged by the requested modification. The spent fuel cask handling crane rails do not extend over the spent fuel pool, and the crane is designed to be single failure proof in accordance with the requirements of NUREG-055e to preclude a l
drop on safety related equipment.
In addition, the crane meets the 1
quidelines of NUREG-0612. Acccrdingly, the consequences of a cask drop t
accident are not significantly increased from previously evaluated events.
All potential events which involve accidental criticality have been examined in the licensees' safety analysis.
It was concluded that the bounding accident was a dropped or misplaced fuel assembly outside the periphery of the racks. The probability of dropping or misplacing a fuel assembly during fuel movement operations is not affected by the. fuel storage racks themselves. The consequences of a criticality accident will not be significantly increased from previously evaluated events because the licensees' criticality calculations show that K,ff would be less than 0.95 and'the, criticality acceptance criterion would not be violated.
The consequences of an installation accident or load handling accident (i.e., dropping of a spent fuel rack or other " heavy" load during rack replacement) are analyzed in Sections 3.4.1 and 4.7 of the licensees' l
. submittal. As indicated in these Sectio.is, precautions will be taken via administrative procedures based upon the criteria of~ Section 5.1.1 'of ~ ~
NUREG-0612 (Control of Heavy Loads at Nuclear Power Plants) to preclude the movement of racks or other " heavy" loads over spent fuel. Thus, the consequences of an accident during rack replacement will not be significantly increased from previously evaluated accidents. The proposed reracking will not involve an increase in the probability of any previously evaluated installations or load handling accident because accepted standard pr.ocedures will be utilized as described in the licensees' submittal.
Therefore, it is concluded that the proposed request to rerack the spent fuel pool will not involve a significant increase in the probability or consequences of an accident'previously evaluated.
Second Standard Create the possibility of a new or different kind of accident from any accident previously evaluated.
The proposed reracking was evaluated by the licensees in accordance with the guidance of the Commission position paper entitled, "0T Position for Review and Acceptance of Spent Fuel Storage and Handling Applications",
Commission Regulatory Guides, NRC Standard Review Plans, and Industry Codes and Standards as listed in the licensees' submittal.
In addition, several previous Commission SEs for rerack applications similar to this proposal have been reviewed. The nuclear criticality design considerations and analysis methods used for Peach Bottom are the same as those used by the Peach Bottom rack vendor (Westinghouse) for several other nuclear power plants which the Consnission has previously reviewed and found acceptable W
_9 (e.g., Shearon Harris 1, 2, 3 and 4 and River Bend '1).
Neither the licensees' nor the Commission's staff could identify i~bredible mechanism for breaching the structural integrity of the spent fuel pool which could result in loss of cooling water such that cooling flow could not be maintained.
As a result of this evaluation and these reviews, it is concluded that the proposed reracking does not, in any way, create the possibility of a new or different kind of accident from any accident previously evaluated for the Peach Bottom spent fuel storage racks.
Third Standard Involve a significant reduction in a margin of safety.
The Comission's staff safety evaluation review process has established that the issue of margin of safety, when applied to a reracking modification, will need to address the following areas:
1.
Nuclear criticality considerations 2.
Thermal-hydraulic considerations 3.
Mechanical, material and structural considerations The established acceptance criteria for criticality is that the neutron multiplication factor in spent fuel pools shall bs less than or equal to 0.95, including all uncertainties, under all conditions. This margin of safety has been adhered to in the criticality analysis methods for the new rack design as discussed in the licensees' submittals.
In meeting the acceptance criteria for criticality in spent fuel pools, such that K,ff is always less than 0.95, including uncertainties of 95/95 probability confidence level, the proposed reracking will not involve a significant reduction in the margin of safety for nuclear criticality, n
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. For thermal hydraulics the relevant considerations for evaluating whether there is a significant reduction in a margin of safety are (1) maximum fuel temperature, and (2) the increase in temperature of water in the pool. The licensees have stated in their therwel hydraulic analysis conservative methods were used to calculate the maximum fuel temperature and the increase in temperature of the water in the spent fuel pool. The calculated maximum fuel cladding temperature of 254 F is sufficiently low to preclude structural failure. Boiling would not occur within the storage locations since the calculated maximum water temperature of 225*F under such conditions is below the saturation temperature at the top of the racks of approximately 240 F.
The maximum water temperature of 135"F was calculated for a normal refueling operation with two out of three heat exchangers in service. With only one heat exchanger in service, the design basis temperature of 150 F would be reached in approximately 7.3 days.
This maximum temperature increase above 150"F after 7.3 days is not significant because the spent fuel pool water temperature is continuously monitored and alarmed in the control room and, therefore, appropriate actions can be taken should the spent fuel pool water temperature approach 150 F during refueling operations. The licensees have calculated that under abnornal conditions, all three heat exchangers must be in service to maintain pool temperature below 150*F. With fewer than three heat exchangers in service and the abnormal conditions outlined by the licensees, maximum spent fuel pool heat loads in excess of 150'F would occur between 7.3 and 26.9 days, assuming an initial temperature of 110*F.
In these I
cases, the Residual Heat Removal (RHR) System would be available, if necessary, l
1 l
to supplement the spent fuel pool cooling system to maintain temperatures below 150*F. These heat loads are well within the capability of the RHR system.
Thus, there is no significant reduction in the margin of safety for thermal-hydraulic or spent fuel cooling concerns.
- The main safety function of the spent fuel pool and the racks is to maintain the spent fuel assemblies in a safe configuration through all normal and abnormal loadings, such as an earthquake, impact due to a spent fuel cask drop, drop of a spent fuel assembly, or drop of any other heavy object. The mechanical, material, and structural considerations of the proposed rerack are described in the licensees' submittals. The proposed racks are to be designed in accordance with the applicable portions of the. "NRC Position for Review and Acceptance of Spent Fuel Storage and Handling Applications", dated April 14, 1978, as modified January 18, 1979, and Standard Review Plan 3.8.4.
The rack materials used are compatible with the spent fuel pool environment and the spent fuel assemblies. The structural considerations of the new racks address margins of safety against tilting and sliding, including impact on each other, or the pool walls, damage of spent fuel assemblies, and criticality concerns. As previously stated, neither the licensees nor the Comission's staff could identify a credible mechanism for breaching the structural integrity of the spent fuel pool which could result in loss of cooling water such that cooling flow could not be maintained.
Thus, the margins of safety in these regards are not significantly reduced by the proposed rerack.
Summary The licensees' request to modify the spent fuel storage capacity for the Peach Bottom Atomic Power Station, Units 2 and 3, satisfies the following conditions:
(1) the storage capacity expansion method consists of modifying the existing racks with a design which allows closer spacing between stored spent fuel assemblies; (2) the storage capacity expansion method does not involve rod consolidation or double tiers; (3) the K,ff of the pools are y
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. maintained less than or equal to 0.95; and, (4) the proposed reracking design
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is based upon well developed and demonstrated technologies.
The request does' not involve significant hazards consideration in that it:
(1) does not involve a significant increase in the probability or consequences of an accident previously evaluated, (2) does not create the possibility of a new or different kind of accident from any accident previously evaluated, and (3) does not involve a significant reduction in a margin of stfety.
Because the licensees' submittal and the above discussion based.upon the licensees' submittal appear to demonstrate that the standards specified in 10 CFR 550.92 are met, and because this reracking technology has been well developed and deconstrated, the Commission proposes to determine that operation of the facility in accordance with the proposed amendments does not involve a significant hazards consideration.
The Commission is seeking public comments on this proposed determination.
Any comments received within 30 days after the date of publication of this notice will be considered in making any final determination.
The Commission will not normally make a final determination unless it receives a request for a hearing.
Written comments may be submitted to the Rules and Procedures Branch, Division of Rules and Records, Office of Administration, U.S. Nuclear Regulatory Commission, Washington, D.C.
20555. Copies of comments received may be examined at the NRC Public Document Room, 1717 H Street, N.W.,
Washington, D.C.
- 20555, i
. By January 13, 1986, the licensees may file a request for a hearing with respect.to issuance of the amendmer.ts to the subject facility operating licenses and any person whose interest may be affected by this proceeding and who wishes to participate as a party in the proceeding must file a written petition for leave to intervene. Request for a hearing and petitions for leave to intervene shall be filed in accordance with the Commission's " Rules of Practice for Domestic Licensing Proceedings" in 10 CFR Part 2.
If a request for a hearing or petition for leave to intervene is filed by the above date, the Comission or an Atomic Safety and Licensing Board, designated by the Commission or by the Chairman of the Atomic Safety and Licensing Board Panel, will rule on the request and/or petition and the Secretary or the designated Atomic Safety and Licensing Board will issue a notice of hearing or an appropriate order.
As required b'y 10 CFR %2.714, a petition for leave to intervene shall set forth with particularity the interest of the petitioner in the proceeding and how that interest may be affected by the results of the proceeding.
The petition should specifically explain the reasons why intervention should be permitted with particular reference to the following factors:
(1) the nature of the petitioner's right under the Act to be made a party to the proceeding; (2) the nature and extent of the petitioner,'s property, financial, or other interest in the proceeding; and (3) the possible effect of any order which may be entered in the proceeding on the I
petitioner s interest. The petition should also identify the specific aspect (s) of the subject matter of the proceeding as to which petitioner wishes to intervene. Any person who has filed a petition for leave to n _.
. intervene or who has been admitted as a party may amend the petition without requesting leave of the board up to fifteen (15) days prior to the first prehearing conference scheduled in the proceeding, but such an amended petition must satisfy the specificity requirements described above.
Not later than fifteen (15) days prior to the first prehearing conference scheduled in the proceeding, a petitioner is required to file a supplement to the petition to intervene which must include a list of the contentions which are sought to be litigated in the matter, and the. bases for each contention set forth with reasonable specificity, pursuant to 10 CFR 92.714(b). Contentions shall be limited to matters within the scope of the amendments under consideration. A petitioner who fails to file such a supplement which satisfies these requirements with respect to at least one contention will not be pennitted to participate as a party.
The Comission hereby provides notice that this is a proceeding on an application for a license amendment falling.within the scope of Section 134 of the Nuclear Waste Policy Act of 1982 (NWPA), 42 U.S.C. 910154. Under Section 134 of the NWPA, the Commission, at the request of any party to the proceeding, is authorized to use hybrid hearing procedures with respect to "any matter which the Commission determines to be in controversy among the parties." The hybrid procedures in Section 134 provide for oral argument on matters in controversy, preceded by discovery under the Commission's rules, and the designation, following argument, of only those factual issues that involve a genuine and substantial dispute, together with any remaining questions of law, to be resolved in an adjudicatory hearing. Actual adjudicatory hearings are to be held on only those issues found to meet the criteria of Section 134 and set for hearing after oral argument.
. The Commission's rules implementing Section 134 of the NWPA are found in 10 CFR Part 2, Subpart K, " Hybrid Hearing Procedures for Expansion of Spent Nuclear Fuel Storage Capacity at Civilian Nuclear Power Reactors" (published at 50 FR 41662 (October 15,1985)).
Under those rules, any party to the proceeding may insoke the hybrid hearing procedures by filing with the presiding officer a written request for oral argument under 10 CFR 2.li To be timely, the request must be filed within ten (10) days of an ords-granting a request for hearing or petition to intervene.
lA5 outlined above, the Commission's rules in 10 CFR Part 2, Subpart G, ccntinue to govern the filing of requests for a hearing or petitions to intervene, as well as the admission of contentions.) The presiding officer shall grant a timely request for oral argument. The presiding officer may grant an untimely request for oral argument only upon a showing of good cause by the requesting party for the failure to file on time and after providing the other parties an opportunity to rerpond to the untimely request.
If the presiding officer grants a request for oral argument, any hearing held on the application shall be conducted in accordance with the hybrid hearing procedures.
In essence, those procedures limit the time available for discovery and require that an oral argument be held to detennine whether any contentions must be resolved in an adjudicatory hearing.
If no party to the proceeding requests oral argument, or if all untimely requests for oral argument are denied, then the usual procedures in 10 CFR Part 2. Subpart G, apply.
Subject to the above requirements and any limitations in the order granting leave to intervene, those permitted-to intervene become parties to l
the proceeding and have the opportunity to participate fully in the conduct I
of any hearing which is held, including the opportunity to present evidence and cross-examine witnesses at such hearing.
. If a hearing is requested, the Commission will make a final determination on the issue of no significant hazards consideration. The final determination will serve to decide when the hearing is held.
If the final determination is that the amendment request involves no significant hazards consideration, the Commission may issue the amendments and make them effective, notwithstanding the request for a hearing. Any hearing held would take place after issuance of the amendments.
If the final determination is that the amendments involve a significant hazards consideration, any hearing held would take place before the issuance of any anendments.
Normally, the Commission will not issue the amendments until the expiration of the 30-day notice period.
However, should circumstances change during the notice period such that failure to act in a timely way would result, for example, in derating or shutdown of the facility, the Commission may issue the license amendments before the expiration of the 30-day notice period, provided that its final determination is that the amendments involve no significant hazards consideration. The final determination will consider all public and State comments received.
Should th'e Commission take this action, it will publish a notice of issuance and provide for opportunity for a hearing after issuance. The Commission expects that the need to take this action will occur very infrequently.
A request for a hearing or a petition for leave to intervene must be filed with 'the Secretary of the Commisison, U.S. Nuclear Regulatory Commission, Washington, D.C.
20555, Attention: Docketing and Service v-m
. Branch, or may be delivered to the Commission's Public Document Room,1717 H Street, N.W., Washington, D.C., by the above date. Where petitions are filed during the last ten (10) days of the notice period, it is requested that the petitioner promptly so inform the Comission by a toll-free telephone call to Western Union at (800) 325-6000 (in Missouri (800) 342-6700). The Western Union operator should be given Datagram Identification Number 3737 and the following message addressed to Daniel R. Muller:
petitioner's name and telepnone number; date petition was mailed; plant name; and publication date and page number of this FEDERAL REGISTER notice. A copy of the petition should also be sent to the Executive Legal Director, U.S. Nuclear Regulatory Commission, Washington, D.C.
20555, and to Troy B. Conner, Jr.,1747 Pennsylvania Avenue, N.W., Washington, D.C.
20006, attorney. for Philadelphia Electric Company.
Nontimely filings of petitions for leave to intervene, amended petitions, supplemental petitions and/or requests for hearing will not be entertaired absent a determination by the Comission, the presiding officer or the presiding Atomic Safety and Licensing Board, that the petition and/or request should be granted based upon a balancing of the factors specified in 10 CFR 92.714(a)(1)(1)-(v) and ?.714(d).
For further details with respect to this action, see the licensees' submittal dated June 13, 1985, as supplemented by letters dated August 1, 1985, and October 9, 1985. These documents are available for public inspection at the Comission's Public Document Room,1717 H Street, N.W.,
- Washington, D.C., and at the Government Publications Section, State Library of Pennsylvania. Education Building, Commonwealth and Walnut Streets, Harrisburg, Pennsylvania.
Dated at Bethesda, Maryland, this 3rd day of December 1985.
FOR THE NUCLEAR REGULATORY ISSION 4
<(
Daniel R. Muller, Director BWR Project Directorate #2 Division of BWR Licensing O
S T