ML20217F912
| ML20217F912 | |
| Person / Time | |
|---|---|
| Site: | Paducah Gaseous Diffusion Plant |
| Issue date: | 07/31/1997 |
| From: | John Miller UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Paperiello C NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20217F916 | List: |
| References | |
| GDP-97-0136, GDP-97-136, NUDOCS 9708070050 | |
| Download: ML20217F912 (28) | |
Text
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United Statis Enrichmint Corporation 2 Democracy Center 6903 Rockledge Drive Dethesda, MD 20817 Tel: (301)564 3200 li itnl Salm ti 10nrichmerit Corlmratiott JAMES H. MILLER Dir: (301) 564-3309 VICE PRESIDENT, PRooUCTION Fax: (301) 571-8279 July 31,1997 Dr. Carl J. Paperiello SERIAL: GDP 97-0136 Director, Oflice of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Paducah Gaseous Diffusion Plant (PGDP)
Docket No. 70-7001
' Certificate Amendment Request - Buildings C-331 and C-335 Seismic Upgrades
Dear Dr. Paperiello:
In accordance with 10 CFR 76.45, the United States Enrichment Corporation (U TEC) hereby submits a request for amendment to the certificate of compliance for the Paducah, Kentucky Gaseous Diffusion Plant (GDP). This request is related to the planned modifications to upgrade the seismic capability of Buildings C-331 and C-335 as described in Issue 36 of DOE /ORO-2026, Plan for Achieving Compliance with NRC Regulations at the Paducah Gaseous Diffusion Plant (Compliance Plan). This request is in response to USEC Letter GDP 97-0101 dated June 30,1997 which committed to provide an update to Compliance Plan Issue 36 outlining new information on the ongoing seismic analyses and new proposed actions. This amendment request revises our previous amendment request on this subject (reference USEC Letter GDP 97-0062, dated April 23,1997).
This amendment request contains the following issues that require NRC review. These issues are i
described in tr.are detailin Enclosure 1.
f As a result of the 10 CFR 76.68(a) review of the proposed modifications to Buildings C-331 and C-335, three issues have been identified as unreviewed safety questions (USQs) requiring h
prior NRC review and approval: (1) the increased stiffness of the buildings following i
completion of the modifications may increase the number and the probability of seismically-h ll1111115ElfIllElll 9708070050 970731 PDR ADOCK 07007001 M
PDR Offices in Paducah. Kentucky Portsmouth. Ohio Washington. DC w
Dr. Carl J. Paperiello July 31,1997 GDP 97-0136 Page 2 induced equipment failures inside the buildings; (2) the process of installing the new structural steel may temporauly make the building and contained equipment more susceptible to seismically-induced failure as the existing structural frames are altered and/or replaced; and (3) the process ofinstalling the new stmetural steel may temporarily increase the probability of quipment failures due to postulated load handling accidents during construction.
Enclosures 5 and 6 are copies of the equipment failure analyses that have been completed in support of the resolut on of USQ (1).
i Compliance Plan issue 36 specifies a December 31, 1997 completion date for these modifications (pending DOE approval of USEC request with justification for a delay).
Ilowever, because of the need to obtain prior NRC review and approval of the identified USQs and because of the need to consider new mformation related to the seismic modifications, the planned modifications cannot be completed by December 31, 1997.
Proposed changes to the Justification for Continued Operation (JCO) and the Plan of Action and Schedule for Compliance Plan Issue 36 are prosided in Enclosure 2.
The JCO for Compliance Plan Issue 36 discusses emergency response to a postulated seismic event, including sheltering or evacuation of the general public.110 wever, current USEC emergency response guidelines recommend sheltering only in response to UF releases. A 6
proposed change to the JCO for Compliance Plan Issue 36 is prosided in Enclosure 2.
The JCO for Compliance Plan Issue 36 currently identifies that the upgraded SAR seismic equipment analysis for Buildings C-331 and C-335 is not yet complete. Ilowever, the final design of the C-331 and C-335 structural modifications has now been completed (Reference USEC Letter GDP 97-0138 dated July 31, 1997). A proposed change to the JCO for Compliance Plan Issue 36 is provided in Enclosure 2.
A DOE-sponsored study performed by Lawrence Livermore National Laboratory (LLNL) has been completed which reviewed the health risks to workers and the public from potential UF 6 releases due to a seismic event. The study found the seismic risk to be low and that operation of Buildings C-331 and C-335 in the current weakened state represents only a modestly higher risk. The conclusions of this study provide further support of the conclusions of the JCO for Compliance Plan Issue 36. A proposed change to reference the study in the JCO for Compliance Plan Issue 36 has been included in Enclosure 2.
USEC is committed to resching the issues identified in Compliance Plan Issue 36 regarding the seismic capability of Buildings C-331 and C-335 on the soonest possible schedule, including structural modifications to the buildings ifjustified. Consequently, USEC requests that this certificate amendment request receive a high priority and that NRC review and approval of this certificate amendment request occur as soon as possilAe. Construction activities on the modifications have been stopped pending NRC's review of this amendment request. The amendment should become etrective no later than 15 days from issuance.
~.. -. _ _.. _ _ _.. _. _
Dr. Carl J. Paperiello
- July 31,1997.
GDP.97-0136 Page 3 Any questions related to this subject should be directed to Mr. Steve Routh at (301)' 564-3251, New commitments made in this submittal are identified in Enclosure 4; 4 __
Sincerely,
$t A
~
mes H. Miller Vice President, Production cc:
NRC Region III Oflice, w/ enclosures -
NRC Resident Inspector - PORTS, w/o
' NRC Resident Inspector - PGDP, w/ enclosures Mr. Joe W. Parks (DOE), w/ enclosures -
7 Mr. Randall M. DeVault, w/ enclosures 4
e J'
s e
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J l
_~-._.
L
' Dr. Carl J. Paperiello.
- July 31,1997 GDP 97-0136 Page 4
Enclosures:
1.
- United States T Enrichment Corporation (USEC), Proposed Certificate Amendment Request, Buildings C-331 and C-335 Seismic Upgrades, Detailed Description of Change 2.
NRC Certificate Amendment Request, Paducah Gaseous Diffusion Plant, Letter GDP 97-0136, Removal / Insertion Instructions & Pages 3/4,4/5 of Compliance Plan Issue 36 3.
United States Enri:hment Corporation (USEC), Proposed Certificate Amendment Request, Buildings C-331 arid C-335 Seismic Upgrades, Significance Determination 4.
Commitments Contained in this Submittal
~
5.
DAC-M0848401-SAR-6'2, " Source Terms for Paducah Evaluation Basis Seismic Event," Lockheed Martin Energy Systems, Inc., Revision 0.
6.
DAC-M0848401-SAR-62, Addendum 1, " Revised Source Terms for Paducah.
_ Evaluation Basis Seismic Event," Lockheed Martin Energy Systems, Inc.,
June 20,1997.
7.
DAC-M0848401-SAR-64, " Evaluation of Atmospheric Dispersion: Seismic Event at the Paducah Gaseous Diffusion Plant," October 11, 1996..
8.
K/GDP/SAR-127/R2, " Cumulative Seismic Effects for Paducah Gaseous Diffusion Plant "00" Buildings C-331 and C-335 Piping and Equipment,"
Lockheed Martin Energy Systems, Inc., March 1997.
t
1 OATH AND AFFIRMATION l
1,- James H. Miller, swear and affirm that I am Vice President, Production,' of the United States Enrichment Corporation (USEC), that I am authorized by USEC to sign and file with the Nuclear Regulatory Commission this Certificate Amendment Request for the Paducah Gaseous Diffusion Plant,.
that I am familiar with the contents thereof, and that the statements made and matters set forth therein are true and correct to the best of my knowledge, information, and belief, James H. Miller Subscribed to before me on this b I day of l
,1997.
l lb) $- lh
-Notary Public 1
i.-
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Enclosure I to GDP 97-0136 Page1of9 United States Enrichment Corporation (USEC)
Certificate Amendment Request Buildings C-331 and C-335 Seismic Upgrades
/
Detailed Description of Change' 1.0 Purpose 1
The purpose of this certificate amendment is to request NRC review and approval of the following issues related to issue 36," Seismic Capability of Buildings C-331 and C-335," of DOE /ORO-2026, Plan for Achieving Compliance with NRC Regulations at the Paducah Gaseous Diffusion Plant (Compliance Plan):
As a result of the 10 CFR 76.68(a) review of the proposed modifications to Buildings C-0 331 and C-335, three issues have been identified as unreviewed safety questions (USQs) requiring prior NRC review and approval: (1) the increased stiffness of the buildings following completion of the modifications may increase the number and the probability of seismically-induced equipment failures inside the buildings; (2) the process of installing the new structural steel may temporarily make the building.md contained equipment more susceptible to seismically-induced failure as the existing structural frames are altered and/or replaced; and (3) the process ofinstalling the new structural steel may temporarily increase the probability of equipment failures due to postulated load handling accidents during construction.
Compliance Plan issue 36 specifies a December 31,1997 completion date for these l
modifications (pending DOE approval of USEC request with justification for a delay).
l However, because of the need to obtain prior NRC review and approval of the identified l
USQs and because of the need to consider new information related to the seismic l
modifications as discussed in Reference 2, the planned modifications cannot be completed l
by December 31,1997.
l The justification for continued operation (JCO) for Compliance Plan Issue 36 discusses emergency response to a postulated seismic event, including sheltering or evacuation of the general public. However, current USEC emergency response guidelines recommend sheltering only in response to UF releases.
6
' Revision bars identify changes from Enclosure 1 of USEC Letter GDP 97-0062, dated l
April 23,1997 (Reference 1).
l
. - -. ~ _.
4 4-to GDP 97-0136 Page 2 of 9 The JCO for Compiiance Plan Issue 36 currently identifies that the upgraded S AR seismic j
equipment analysis for Buildings C-331 and C 335 is not yet complete. However, the I
final design of the C-331 and C-335 structural modifications has now been completed l
(Reference 3).
l l
A DOE-sponsored study performed by Lawrence Livermore National Laboratory (LLNL) l j
has been completed which reviewed the health risks to workers and the public from l
potential UF releases due to a seismic event (Refen a 4). The study found the seismic _ l 6
risk to be low and that operation of Buildings C-331 e. C-335 in the current weakened l
state represents only a modestly higher risk. The conclusions of this study provide further l
. support of the conclusions of the JCO for Compliance Plan Issue 36.
l t
2.0 -
Background
Compliance Plan issue 36 requires USEC to upgrade the structural capacity of Buildings C-331 4
and C-335 to withstand a 0.15 g magnitude earthquake and presentr. justification for continued operation of these buildings during the interim period until the seismic modifications are completed. As required by the JCO, the following compensatory measures are being implemented during this interim e
_ period:
Operations in Buildings C-331 and C-335 are limited to subatmospheric pressure within a
the enrichment cascade equipment, 1
Operations personnel have been instructed on the specific emergency procedures for shutting down the affected enrichment cascade and building ventilation systems following a seismic event.
Building access is limited to only those individuals essential to operations, inspections, F
or those personnel performing the modifications until they are complete.
i Compliance Plan issue 36 concludes that "..the risk to the public and the on-site workers from 4
the unmitigated response of Buildings C-331 and C-335 is not extreme and can be accepted without undue harm with the compensatory measures imposed on operations remaining in effect until the modifications are complete while the stnictural weaknesses are being corrected."
3.0 -
Discussion ofIssues 3.1 Unreviewed Safety Questions Associated With Planned Seismic Upgrades to Buildings C-331 and C-335 As a result of the 10 CFR 76.68(a) review of the proposed modifications to Buildings C-331 and 4
I
l to GDP 97-0136 Page 3 of 9 C-335, three issues have been identified as unreviewed safety questions (USQs) requiring prior NRC review and approval. These issues are discussed in further detail below.
Issue l-The increased stitTness of the buildings following completion of the modifications may increase the number and the probability of seismically-induced equipment failures inside the buildings.
The following is a summary of this issue:
Table 4.6-2 of the Safety Analysis Report (SAll) identifies equipment currently predicted to fail as a result of an analyzed 0.18 g magnitude earthquake.
Table 1 of Reference 5 and Table 1.1 of Reference 6 identify equipment in Buildings l
C-331 and C-335 predicted to fail as a result of a revised Evaluation Basis Earthquake of l 0.15 g once the structural modifications are completed. Some of the process equipment l
failures identified in Table 5 of Reference 1 and Table 1.1 of Reference 6 are different l
than the process equipment failures identified in SAR Table 4.6-2. References 5 and 6 l
are based on the fmal design of the planned structural modifications to Buildings C-331 l
and C-335.
l Based on the above discussion, this issue has been determined to be an unreviewed safety question because the probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased. The completed structural modifications to Buildings C-331 and C-335 may result in seismically-induced equipment failures different than those currently identified in the SAR.
Although the probability of seismically-induced equipment failures may be increased by the stifrening of Buildings C-331 and C-335, the consequences of these postulated equipment failures are bounded by the seismic failures evaluated in the JCO for Compliance Plan Issue 36. The JCO evaluates four postulated seismic failure cases that predict uranium uptake and HF exposure to individuals (see Table I of Compliance Plan Issue 36). The bounding case emmes a complete building collapse and the i
release ofthe entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated consequences of the small number of equipment failures that may be predicted to result from the stiffening of Buildings C-331 and C-335 (Reference 7).
l i
.. _ _ _ to i
GDP 97-0136 Page 4 of 9 Issue 2 The process ofinstalling the new structural steel may temnorarily make the building and contained equipment more susceptible to seismically-induced failure as the existing structural frames are altered and/or replaced.
The following is a summary of this issue:
SAR Table 4.6 2 identities equipment currently predicted to fail as a result of an analyzed 0.18 g magnitude earthquake.
In various locations in Buildings C-331 and C-335, existing structure.1 framing is planned to be removed and replaced with upgraded structural steel. Consistent with standard practice for upgrading structures, temporary supports or shoring will be used as required and the sequence of removal of old components and installation of new components will be selected based on the stability of the in-process structure. These standard practice techniques account for static and construction-activity dynamic loading, but do not necessarily account for postulated seismic loading. Thus, during the short period of time that a particular location of the building is being modified (on the order of 2 to 3 days for i
cach location), if a seismic event were to occur, there may be an increased probability of l
localized building and/or equipment failures over those currently evaluated in the SAR.
As the project progresses, various portions of the overall structure may be in a weakened condition (as discussed above) while other portions may be unaltered or have their alterations completed.
It is nearly impossible to analyze the various possible combinations of these configurations.
However, because of the variations in seismic / structural response throughout the buildings, there may be an increased probability of building and/or equipment failures should a seismic event occur.
Based on the above discussion, this issue has been determined to be an unreviewed safety question because the probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased. The process of modifying Buildings C-331 and C-335 may temporarily make the buildings and contained equipment more likely to fail during a postulated seismic event.
Although the probability of seismically-induced building and equipment failures may be temporarily increased during the construction process, the consequences of these postulated failures are bounded by the seismic failures evaluated in the JCO for Compliance Plan Issue 36. The JCO evaluates four postulated seismic failure cases that predict uranium uptake and HF exposure to individuals (see Table 1 of Compliance Plan Issue 36). The bounding case assumes a complete building collapse and the release ofthe entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated consequences of any building or equipment failures that may be predicted to result should a seismic event occur during construction activities. In addition, the current restrictions on 1
to GDP 97 0136 Page 5 of 9 subatmospheric operation in 11uildings C-331 and 0-335 serve to further reduce any postulated releases during the construction period below those evaluated in Compliance Plan Issue 36.
Isntd:
The process ofinstalling the new structural steel may temporarily increase the probability of equipment failures due to postulated load handling accidents during construction.
The following is a summary of this issue:
A crane failure accident analysis for the cascade buildings is presented in SAR Section 4.3.2.1.1. This analysis assumes that approximately 200 moves of major equipment are required each year and approximately 2% of the move time is over operating equipment.
The analysis assumes the drop of a "000" compressor (which weighs approximately 33 tons including lining fixtures) onto cascade equipment that is running above atmospheric pressure.
The project plan for installation of the seismic upgrades in Buildings C-331 and C-335 identifies the need for approximately 2300 liRs of structural steel shapes and related materiais in each building. Some of the lins will be over, or in proximity ta, operating Q or AQ equipment, including the cascade. The lins will be hand-rigged (i.e., no crane will be used) and involve structural steel shapes with a length bet,veen 20 and 50 feet, weighing less than 5 tons.
The following controls will be applied to each lin associated with the seismic modifications:
Lift time will be minimized to reduce exposure to drop hazards.
Subatmospheric pressures will be maintained within the cascade process equipment.
Lift plans will be prepared and approved in accordance with plant procedures.
Each lin plan will include step-by-step instructions along with appropriate witness and/or inspection hold points.
The lift will be planned from initial rigging, to lin placement, stabilization, and rigging removal. Planning for each lift will include an identification of actions that would be taken in response to a hypothetical load handling accident.
A construction engineer will be assigned to provide dedicated oversight.
In addition to the controls for each lift described above, the following supplemental controls will be applied for each lift that is over, or in proximity to, operating Q or AQ equipment:
Facility owners will be not fied prior to the lift i
L
T Enclosure I to GDP 97-0136 Page 6 of 9 An Operations representative will witness the lin and will maintain voice contact with the facility Area Control Room (ACR) throughout the lin to ensure that the ACR is notified as quickly as possible should a load handling accident occur.
Based on the above oiscussion, this issue has been determined to be an unreviewed safety question because the probability of a malfunction of equipment important to safety previously evaluated in the safety analysis report may be increased. The number oflins during the planned construction activities exceeds the number oflins currently evaluated in the SAR; thus, a load handling accident impacting equipment important to safety may be more likely to occur during the construction period.
Although the probability of equipment failure as a result of a postulated load handling accident may be temporarily increased during the construction process, the consequences of these postulated l
failures are bounded by failures evaluated in the SAR and the JCO for Compliance Plan Issue 36. First, because the weight of each liR is significantly less than evaluated in S AR Section 4.3.2.1.1 (5 tons versus l
33 tons), a postulated load handling accident would produce less damage to cascade equipment (e.g., size i
of hole, single versus multiple holes, etc.) than assumed by the accident analysis. Second, the JCO for l
Compliance Plan issue 36 evaluates four postulated seismic failure cases that predict uranium uptake and liF exposure to individuals (see Table 1 of Compliance Plan Issue 36). The bounding case assumes a complete building collapse and the release of the entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated consequences of any equipment failures that may be predicted to result due to a postulated load handling accident. In addition, the current restrictions on subatmospheric operation in Buildings C-331 and C-335 serve to further reduce any postulated releases during the construction period below those evaluated in Compliance Plan Issue 36.
3.2 Change in Completion Date for Seismic Modifications to Buildings C-331 and C-335 The Plan of Action and Schedule for Compliance Plan Issue 36 requires that:
Modifications to increase the seismic capability for floor and roof sections in Buildings C-331 and C-335 will be completed by December 31,1997 (pending DOE approval of USEC request with justification for a delay from July 31,1997 -- current commitment date to DOE).
In order to complete the modifications by December 31,1997, the installation of structural steel needed to begin on March 18,1997. However, structural steel installation has not been initiated because l
the 10 CFR 76.68(a) evaluation of the proposed modifications identified three issues as involving l
unreviewed safety questions (see Section 3.1). In addition, new information and considerations have l
caused USEC to question whether the planned modifications to Buildings C-331 and C-335 will l
effectively manage seismic risk at PGDP (see Reference 2). To account for the need to obtain prior NRC l
review and approval of the identified USQs and to address the new information related to the seismic l
modif. cations, USEC requests that the completion date for the seismic modifications be changed in l
EncWtn I to GDP 9/ on6 Page 7 of 9 accordance with the proposed revision to the Plan of Action and Schedule for Compliance Plan Issue 36 l
(see Enclosure 2).
l A review of the JCO for Compliance Plan issue 36 has been performed to determine ~ if any changes are required as a result of extending the completion date for the seismic modifications. The conclusions of this review are that, if the compensatory measures identified in the current JCO remain in effect, continued operation ofBuildings C-331 and C-335 isjustified during the extended period. This l
conclusion is further supported by the conclusions of a DOE-sponsored study performed by Lawrence l
Livermore National Laboratory (see Section 3.5).
l 3.3 Change in Emergency Response to a Postulated Seismic Event The JCO for Compliance Plan Issue 36 describes risks to the general public of a postulated-seismic event and identifies emergency response actions to be taken:
The risk of exposure to the general public of moderate (uptake of 100-150 mg of uranium)'_
and low (50-100 mg uptake) renal injuries was estimated to be 0.15 injuries and 0.78 injuries / year, respectively, assuming no benefit from an emergency response.
If emergency response is considered and credited with a factor of 2 benefit due to either sheltering or evacuation, then the risk is essentially zero, at 0.15 low level renal injuries / year.
This wording indicates that, for the general public, the emergency response that is credited for safety can be either sheltering or evacuation. However, Section 5.4.2 of the Emergency Plan (EP) states i
that the recommended response to emergencies such as releases for the general public outside the site boundary is to seek shelter only (and not evacuation). EP Section 5.4.2 further states that protective actions beyond sheltering would be directed. by off site authorities who are responsible for the members of the public in theirjurhdiction. Although these other protective actions may include evacuation, such an evacuation should not be credited for safety in the JCO because this is an action controlled by off-site authorities arid not by plant personnel The emergency response that should be credited for safety is
- sheltering. A proposed change to the JCO for Compliance Plan Issue 36 has been included in Enclosure 2 to eliminate evacuation as an altemative to be credited for protection of the general public. This change will make the Compliance Plan JCO consistent with the emergency response actions described in the Emergency Plan. The change does not, however, prevent off-site authorities from ordering an evacuation ofthe public.
l o
- -. to GDP 97-0136 Page 8 of 9 3.4 Completion of Final Design of C-331 and C-335 Structural Modifications l
I The JCO for Compliance Plan issue 36 describes the upgraded SAR seismic equipment analys:s j
. for Buildings C-331 and C-335 as not yet complete:
l l
However, the upgraded SAR seismic equipment analysis is not yet complete. Additional l
modifications to equipment could be reconunended depending on the fmdings of the l
remaining equipment evaluations and the analyses of the HF and UO F projected I
2 2 releases.
l i
Because the final design of the C-331 and C-335 structural modifications has now been completed l
(Reference 3), a proposed change to the JCO for Compliance Plan Issue 36 has been included in l
l-to delete the above discussion.
l l
3.5 Lawrence Livermore National Lab Study l
In March 1997, USEC received a copy of a DOE-sponsored study by Lawrence Livermore National Laboratory (LLNL). The study (Reference 4) was commissioned by the DOE to review the 1
health risks to the site workers and the public in the surrounding area that would result from potential l
releases of uranium hexafluoride (UF.) during a seismic event. The study used the consequence l-models contained in the DOE's Upgraded SAR to evaluate the impact of the planned structural 1
modifications to Buildings C-331 and C-335 on this risk. The study foimd the seismic risk to be low l and that operation of Buildings C-331 and C-335 in the current weakened state represents only a j
modestly higher risk. (A copy of DOE's LLNL report was provided to the NRC as Enclosure 3 to l
Reference 2.)
l l
Because the conclusions of the DOE LLNL study further support the conclusions of the JCO for l
Complinace Plan Issue 36, a proposed change to the JCO to reference the results of the study has been l
included in Enclosure 2.
l l
References l
l 1.~
USEC Letter GDP 97-0062, "Cenificate Amendment Request - Buildings C-331 and C-335 l
Seismic Upgrades, April 23,1997.
l l
2.
USEC Letter GDP 97-0101," Seismic Risks and Modifications at PGDP, Compliance Plan issue l
36," June 30,1997.
l i
3.
- USEC Letter GDP 97-0138,." Final Design Information for Planned Structural Modifications to l
Buildings C-331 and C-335, Compliance Plan Issue 36," July 31,1997.
l l
to GDP 97-0136 Page 9 of 9 -
4.
UCRL-ID-126275,"Paducah Gaseous Diffusion Plant Seismic Risk Study," Lawrence Livermore - l National Laboratory, February 1997.
l l
5.
DAC-h10848401-SAR 62, Addendum 1," Revised Source Terms for Paducah Evaluation Basis ll Seismic Event," Lockheed Martin Energy Systems, Inc., June 20,1997.
l l
6;
- K/GDP/SAR-127/R2, " Cumulative Seismic Effects for Paducah Gaseous Diffusion Plant "00" l
l Buildings C-331 and C-335 Piping and Equipment," Lockheed Martin Energy Systems, Inc.,
l l
MarcP 1997.
l i-l-
l-7.
DAC-M0848401-SAR-64, " Evaluation of Atmospheric Dispersion: Seismic Event," Lockheed l
l' Martin Energy Systems, Inc., October 1996.
l l
. to GDP 97-0136 8 Pages Total NRC Certificate Amendment Request Paducah Gaseous DitTusion Plant Letter GDP 97-0136 Removal / Insertion Instructions Remove Pages Insert Pages PLAN FOR ACIllEVING COMPLIANCE WITII NRC REGULATION AT Tile PADUCAll GASEOUS DIFFUSION PLANT (DOE /ORO-2026)
Issue 36, Seismic Capability of Buildings issue 36, Seismic Capability of Huildings C-331 and C-335 C-331 and C-335 Pages 1 - 6 Pages 1 - 7 v
Issue 36, Page I Scismic Capability of Buildings C-331 and C-335 (new issue)
REQUIREMENTS
' 10 CFR 76.35(a)(4), (6), an.d (86"The application for an ;;91al certificate of compliance must include the infonnation identified in this section. 6) A safety analysis report which must include l
the fn!!owing information:
.. (4) An assessraent of accidents based on the requirements of
- /6.85;.. (6) A description of equipment and lacilities which will be used by the Corporation to protect health and minimize danger to life or p+operty (such as... provisions for protection against natural phenomena;... (8) A descriptien of the plant site, and a descrip; ion of the principal structures, systems, and com,ponents of the plant."
10 CFR 76.85 "The Corporation shall perform an analysis of potential accidents and consequences to establish the basis for limiting conditions for operation of the plant with respect to the potential for releases of radioactive material. Special attention must be directed to assurance that plant operation will be conducted in a manner to prevent or to mitigate the consequences from a reasonable spectrum of postulated accidents which include... natural phenomena in order to ensure adequate protection of the public health and safety. Plant operating history relevant to the assessment should be it.cluded in performing this assessment, the full range of operations should be considered including, but not necessarily limited to, operation at the maximum capacity contemplated. The assessment must be performed using an expected release rate resulting from anticipated operational occurrences and accidents with existing systems and procedures intended to mitigate the release consequences, along with site characteristics, including meteorology, to evaluate the offsite radiological consequences."
COMMITMENTS Source: Safety Analysis Report
- 2. Site Characteristics (Rev. 3, 5/31/96)
This chapter provides information on the location and site characteristics of the facility to address 10 CFR 76.35(a)(8), including the historical basis for site characteristics in geology and seismology. This information is needed to support the assumptions that were used in determining the impacts of normal operation, the hazard and accident analysis as described in Chapter 4 of the application, and emergency operations, particularly with regard to the contribution of natural seismic phenomena to the initiation of events and the site related assumptions that were used in evaluating accident consequences.
- 3. Facility and Process Description [Rev. 3, 5/31/96]
This chanter provides information on the principal structures, systems, and components of-the plant as well as information on the equipment and facilities that are used to protect health and minimize danger to life or property to address 10 CFR 76.35(a)(6) and 10 CFR 76.35(a)(8),
including (1) properties of uranium and uranium hexafluoride (U",) and the process and facilities used for enriching UF in the *U isotope; (2) UF. feed racilities and processes; (3) UF, enrichment facilities and processes; and (4) UF product withdrawal facility and PGDP, July 31,1997 PROPOSED l
_A
Issue 36. Page 2 PROPOSl?D Seismic Capability of Iluildings C 331 and C-335 RAC 97C192 processes. This information is needed to support the assumptions that were used in determining the impacts of normal operation, emergency planning, and the hazard and accident analysis as described in Chapter 4 of the application regarding the contribution of facility and process design to initiation of events and the design-related assumptions that were used in evaluating accident consequences."
- 4. Accident Analysis [Rev. 3, 5/31/96]
This chapter provides a description of the accident analyses that were performed to address 10 CFR 76.35(a)(4) and 10 CFR 76.85. The accident analyses consisted of (1) review of operations including the history of failures and accidents; (2) discussion of the methodology used in determining the risk associated with hypothetical accidentst (3) identification of accident scenarios, (4) consequences of accidents; and (5) determination of residual risk. The accident analyses considered natural phenomena including earthquakes.
DESCRIPTION OF NONCOMPLIANCE in 1985, the PGDP was analyzed for a 0.18g peak ground acceleration earthquake loading corresponding to an approximate 250-year earthquake return interval, the Evaluation Basis Earthquake (EBE) established in the 1985 Safety Analysis Report (SAR). Building capacities were shown to be less than this earthquake demand out only minor structural damage was estimated, l
and structural integrity was maintained, llowever, certain cascade piping attachments known as I
expansien joints or bellows were judged to fail in significant numbers within the buildings resulting in a substantial combined release of uranyl fluoride (UO F ) and hydrogen fluoride (IIF) 2 2 from the cascade facilities. Operations were limited to moderate power levels to keep the enrichment process sub-atmospheric until these expansion joints were improved.
Recently, structural seismie loading capacity analyses, perfonned as part of the general safety analyses update of the Paducah Gaseous Diffusion Plant (PGDP), have identified that significant plant damage could occur in two of the main cascade buildings, C-331 and C-335, below the Evaluation Basis Larthquake. This damage could involve the failure of the approximately 20-foot wide spans which traverse each building in three locations of each building's roof. The similarly supported mezzanine and cell floor sections could also fail. The affected spans are attached at one column line and supported by a sliding support known as a
" rocker arm." At a seismic loading above 0.05g, the building columns might be displaced out of phase to a distance greater than the available travel of the extension bracket support catsing the spans to fall, Previous acceptance by DOE of the facility's seismic capability relied on the integrity of the buildings for events up to the Evaluation Basis Earthquake. This potential for loss of the bui' ding integrity has been determined to be an tmreviewed safety question and outside the plant's authorization basis.
JUSTIFICATION FOR CONTINUED OPERATION In response to the Unreviewed Safety Question, structural modifications to improve the bracing in the affected buildings have been developed and are in p; ogress. Specifically, structural cross bracing will be added at specific column locations in the north-south and east-west l directions in Buildings C-331 and C-335 as identified in the detailed design which has been PGDP, July 31,1997 PROPOSED U
Scismic Capability of Duihiings C-331 and C-335 l'BOPOSED issue 36. Page 3 RAC 97C192 prepared to raise the capacity of the structures to a 0.15g magnitude earthquake as defined by the SAR Upgrade Program site specific hazard curve. These modifications will reduce displacements
'thus ensuring the overall building integrity. Completion of the modifications will bring the PGDP l
process building structures into compliance within the interpretation of the 1985 SAR and current seismic requirements for GDP hazardous facilities.
l PGDP plans to continue operation with two process buildings, C-331 and C-335, in a seismically weak condition until the completion of building reinforcement modifications.
l Continued operation of the processes in these buildings is justified in the interim since the increased risk to the general public and on-site workers is within an acceptable level. The risk increase to the public is a small increase in the chance of an exposure to UO F and ilF causing 2 2 minor to moderate renal injuries. The risk increase to some on-site workers is a moderate (factor of 2 to 3) increase in the chance of be:h exposure to toxic releases and physical injury. (See the "Paducah Gaseous Diffusion Plant Justification for Continued Operation: Temporary Operation of Buildings C-331 and C-335 with Potentially Severe Structural Damage Due to Evalustan Basis Earthquake Loads," prepared by the Department ot Lnergy Regulamry Oversight, Oak Ridge, I
TN, dated May 17, 1996.) Compensatory measures were initiated upon recognition of the structural deficiency and will remain in place until the corrective mcalifications are complete.
These measures minimize the number of shift personnel in the affected buildings during the ins -im period, and the allowed power level in the two buildings is limited to mainta'm the c cade subatmospheric thereby minimizing the release after a seismic event.
The conclusion that the risk level is acceptable during the interim operating period is j
supported by evaluations of the consequences to the public and on-site workers from conservative release scenarios based on the projected and bounding building failures that are possible up to the evaluation basis earthquake Physical effects such as the impact of a seismically induced fire also were examined as part of these scenarios.
The projected structural response of the two buildings up to an Evaluation Basis Earthquake (250-year retum interval, peak ground acceleration equivalent: 0.15 g) is the inward collapse of three areas of each building's roof, mezzanines, and cell thor. These areas are about 20 feet wide and run the length of each building in the direction of the structural expansion joint between internal st actural units. The collapse could cause the release of UF., UO,F, and liF. In 2
addition, there is some probability that the buildings could collapse in response to the loading of earthquakes that produce accelerations approaching 0.15g. Based on the possible structural response, four exposure cases were evaluated. A bounding case (Case 1) assumed that the building collapsed (i.e., the building fell over onto its side) and the entire contents of the cascade system was released into the collapsed structures, it should be noted that the load bearH capacity of the converters located throughout the building on the cell floor would prever'.
complete flattening of the structure and provide a vertical air space approximately 8 feet high. The analyzed quantity of the UO F and liF released was not reduced by physical considerations such 2 2 as the material that would remain in the cascade piping and equipment or may deposit in the building or the vicin ty of the building due to aerosol deposition. Ilowever, the effects of i
thermodynamics and the mixing of fluids (water vapor and R Il4 Freon) in the building were considered. Case 2 used a conservative, but more realistic, engineering analysis basis that included an estimate of the UF. that would remain in the converters following the cascade system ruptures. The amount of aerosol dcposition that would occur during the residence time of the release cloud in the buildings was also considered. This release case is a conservative but defendable estimate of the bounding physical state of the building. Cases 3 and 4 are similar cases PGDP, July 31, 1997 PROPOSED
issue 36, Page 4 PROPOSFD Seistnic Capability of Buildings C-331 and C-335 RAC 97Cl92 of the buildings' expected actual structural response to an Evaluation Basis Earthquake event (including the failure of areas of the buildings at the structural expansion joints). Case 3 is based on a highly conservative estimate of thc cascade damage that would be sustained if the roof, mezzanine, and cell floor failed as predicted and no aerosol deposition occurred, Case 4 is the same as case 3 with consideration given to aerosol deposition.
i The results of the four evaluation cases are summarized in the following table:
Table 1. Uranit.m Uptake and 11F exposure
- to Individuals Evaluation Case Meteorology Maximum Maximum IIF Exposure liF Exposure Class-Wind Uranium Inhaled Uiarium Inhaled Concentration Concentration speed (mhec)
Mass (mg) et 1 Mass (mg) u 5 (ppm)-1 mile (ppm)--$ miles mile miles
- 1. Building Collapse-No retention in D-4 139 70 38 19 Cascade (Bounding Case)
II. Duildbg Collapse-Conservative D4 45 16 15 5
essmate o, retention in Cascade III, Partial l
Duilding Failure p,3 33 7
37 3
with No Accosol Deposition IV. Partial Building Failure F-3 20 4
11 2
with Mrosol g Deposition
- IIF exposures are based on i hour average concentrations.
The results of all but the bounding case (Case 1) show the potential for mij a mild exposure, nearly within the accident evaluation guidelines. The bouteding case consequences itxlicate the potential for significant renal injury, that would not be potentially life threatening at one mile distance from the release point. One mile is essentially the distance to the site boundary from the buildings in question. The risk of exposure to the general public of moderate (uptake of 100-150 mg of uranium) and low (50-100 mg uptake) renal injuries was estimated to be 0.15 injuries and 0.78 injuries / year, respectively, assuming no benefit from an emergency response.
If emergency response is considered and credited with a factor of 2 benefit due to sheltering, then the risk is essentially zero, at 0.15 low level renal injuries / year, Given the higitly conservative nature of the evalaation of the release and the low consequences, continued operation does not pose a significant undue risk to the public during the pe..od of operations until building modifications are completed.
The risk to workers in the buildings was estimated as well. Based on an assumed 5 percent chanee of building collapse and a 50 percent chance of being present in the building (i e., on PGDP, July 31,1997 PROPOSED
Seismic Capability of Building C-331 and C 335 PROPOSED issue 36, Page 5 RAC 97C192 shift), the injury rate to individual workers was estimated at approximately 1 x 10" per year with a total injury rate risk estimated at 2.6x 10-3 injuries per year (for an operating staff of 26). This is judged to be acceptable and is no greater than the risk of general office work on-site. Injury from struuures may even be higher in the of0ce buildings, although the probability of exposure to ilF and UO F releases would be greater in the process buildings. This conclusion is further 2 2 supported by a DOE sponsored study performed by Lawrence Livermore Nationa! Laboratory (LLNL) to review the health risks to workers and the public from potential UF. releases due to a seismic event ("Paducah Gaseous Diffusion Plant Seismic Risk Study,"UCRL-ID-126275 February 1997). Tl.a LOE LLNL study also found the seismic risk to be low and that operation of Buildings C-331 and C-335 in the current weakened state represents only a modestly higher risk.
Therefore, it is concluded that the risk to the public and the on-site workers from the unmitigated response of Buildings C-331 and C-335 is not extreme and can be accepted dthout undue hami with the compensatory measures imposed on operations remaining in effect until the modifications are complete while the structural weaknesses are being corrected.
fs t.
l PLAN OF ACTION AND SCIIEDULE The actions to upgrade the seismic capabilities of Buildings C-331 and C-335 are as follows:
l 1.
Based on a Directive for Infonnation provided to USEC by DOE on September 22,1995, the USEC evaluation of the currently available information from the DOE safety analysis upgrade dfc:: :clated to seismic capabilities at the facili y completed on October 23,1995, t
the DOE evaluation of the USEC response dated October 31, 1995, USEC's proposed resolution documented on January 9,1996, ami USEC's certificate amendment request dates' July 31,1997, the following actions are being implemented to ensure the protection of the workers and public health and safety:
Until the completion of modifications discussed below, operations in Buildings C-331 and C-335 will be limited to subatmospheric pressure within the carichment cascade equipment.
Operatior personnel will be instructed on the specific emergency procedures for shutting down the affected enrichment cascade equipment and building ventilation systems following a seismic event.
Building access will be limited to only those individuals essential to operations, inspections, or those peuonnel performing the modifications until they are complete.
Modifications to increase the seismic capability for floor and roof sections in Buildings C-331 and C-335 will be completed according to the following schedule:
(a) USEC prepares and submit the final design of the C-331 and C-335 structural modifications required by item 3 below.
PGDP, July 31, 1997 PROPOSED l
Issue 36, Page 6 PROPOSED Seismic Capability of Buildinp C 331 and C 335 RAC 97C192 (b) NRC ccmpletes review of the three unreviewed safety questions identified in USEC letter GDP 97-0062, dated April 23,1997 as modified by USEC letter GDP 97-0136 dated July 31,1997.
(c) NRC completes review of the final design of the C-331 and C-335 structural modifications.
(d) USEC completes review of the DOE Upgraded SAR and incorporates the seismic analyses into USEC's Updated SAR in accordance with Compliance Plan issue 2.
(e) NRC completes review of the seismic analyses included in USEC's Updated SAR.
(f) USEC completes the updated seismic risk analysis required by item 4 below, if the current modifications are confirmed by these analyses, USEC will proceed with the modification of Buildings C-331 and C-335. The modifications v ill be installed l
within 18 months from release of the project, if activities (a) through (f) indicate that a different set of modifications than those currently planned should be pursued, USEC will proceed with development of a reconunendation for a new set of actions as follows:
(g) USEC identifies to NRC the need for a different set of modifications and operating controls and proposes a general design approach by December 1,1997.
(h) NRC completes review of the updated seismic risk analysis and USEC's planned approach in (g).
(i) USEC identifies necessary structural modifications and operating controls for effective managment of the dominant seismic risk at PGDP and submits for.NRC approval within 4 months following completion of (h).
(j) NRC completes review of USEC's submittal described in (i).
2.
At the time of transition from DOE regulatory oversight to NRC regulatory oversight, USEC will inform NRC of the interim measures rtill in effect for the affected buildings and equipment and the current status of upgrading the seismic capabilities of the affected buildings and equipment.
3.
Documentation prepared for the design of the modification and other relevant information concerning implementation will be provided to the NRC, upon issue, for information and review.
4.
By December 1,1997, USEC shall submit for NRC approval an updated seismic risk analysis for the Paducah plant site. The analysis shall:
Consider all available regional and site-specific data published by the U.S. Geological Survey.
PGDP, July 31, 1997 PROPOSED
Seismic Capability of liulldings C-331 and C 335 PROPOSED issue 36, Page 7 RAC 97C192 Provide an estimate of the peak ground acceleration for a seismic event with a 250-year return period. If the estimate is greater than 0.15g, then the return period for a 0.15g j
event shall also be estimated.
Any proposed modifications that may result from this analysis shall be subject to a backfit analysis pursuant to 10 CFR 76.76(b).
SUnih!ARY OF REQUIREhtENTS, COhlh!!ThlENTS, AND NONCOh!PLIANCES Issue: Seismic Capability of Buildings C-331 and C-335 Code of Federal Regulailons Part Title 10 76.35(a)(4), 76.35(a)(6), 76.35(a)(8), 76.85 i
Application Conunitment Section Safety Analysis Report 2.1.1, 2.6, 3.1, 3.3, 3.4, 4.2.2.6, 4.6.1, 4.7, Table 4,9-1 Application Noncompliance Statement Section Safety Aaalysis Report 2.7. 3.16.1, 4.10 PGDP, July 31, 1997 PROPOSED
._ to GDP 97-0136 Page1 of5 United States Enrichment Corporation (USEC)
CertiGente Amendment Request Buildings C-331 and C-335 Seismic Upgrades Significance Determination' The United States Enrichment Corporation (USEC) has reviewed the proposed changes associated with this - cenificate amendment request and provides the following Significance Determination for consideration.
1.
No Overall Decrease in the Effectiveness of the Plant's Safety. Safecuards. or Security Prourams This cenificate amendment requests NRC review of: three unreviewed safety questions (USQs) l associated with the seismic upgrades to Buildings C-331 and C-335, a change to the completion l
date for these modifications, and several changes to Compliance Plan Issue 36 to identify the l
completion of the final design of the structural modifications and to include a reference to the l
l DOE LLNL seismic risk study. The seismic / structural capacity of13uildings C-331 and C-335 l
is not addressed in the plant safety, safeguards, or security programs contained in Volume 3 of the Application for United States Nuclear Regulatory Commission Certification for the Paducah Gaseous Diffusion Plant.
This certificate amendment also requests.NRC review and approval of a change to the Justification for Continued Operation (JCO) for Compliance Plan Issue 36, " Seismic Capability of Buildings C-331 and C-335," to remove the reference to evacuation as an alternative to be credited for protecting the safety c f the general public in response to a postulated seismic event.
This change will make the Compliance Plan JCO consistent with the recommended response of sheltering only for the general public (and not evacuation) as described in the Emergency Plan.
Also, the change does not prevent off-site authorities from ordering an evacuation of the public as described in the Emergency Plan.
For these reasons, the etrectiveness of the plant's safety, safeguards, and security programs is unafrected by this certificate amendment.
2.
No Sienificant Channe to Any Conditions to the Certificate of Comnliance None of the Conditions to the Certificate of Compliance address the specific USQs raised, the schedule for completing the seismic upgrades to Buildings C-331 and C-335, the changes to l
Compliance Plan Issue 36 to identify the completion of the final design of the structural l
modifications and to reference the DOE LLNL seismic risk study, or evacuation as an optional l
response in an emergency. Thus, the proposed changes have no impact on any of the Conditions
. to the Certificate of Compliance.
' Revision bars identify changes # om Enclosure 3 to USEC Letter GDP 97-0062 dated l
April 23,1997, l
)
. to GDP 97-0136 Page 2 of 5 3.
No Significant Change to Any Condition of the Approved Comnliance Plan Issue 36 is the only portion of the Compliance Plan affected by the proposed changes. The identified USQs do not have a direct impact on this Compliance Plan issue. In fact, the consequences of the postulated seismic failures evaluated in the JCO for Compliance Plan Issue 36 bound the consequences of the identified USQs Ilowever, because of the need to obtain NRC l
review of the USQs and because of the need to consider new information related to the effective j
management of seismic risk at PGDP, a change to the scheduled completion date for the seismic l
upgrades is needed. Extending the completion date for the modifications is not a significant l
change because the JCO for Compliance Plan Issue 36 will remain in efTect until the modifications are completed, including the required compensatory measures.
The change to Compliance Plan Issue 36 to identify the completion of the final design of the l
structural modifications is not significant because it updates the Compliance Plan with current I
status. Adding a reference to the DOE LLNL seismic risk study is not significant because the l
conclusions of the study provide further support of the JCO for Compliance Plan Issue 36.
l Removing the reference to evacuation as an alternative for protecting the safety of the general public is not a significant change because sheltering pavides equivalent protection. Also, the change does not prevent off-site authorities from ordering an evacuation of the public.
4.
No Significant Increase in the Probability of Occurrence or Consecuences of Previousiv Evaluated Accidents a.
Issue I has been identified as a USQ because the increa.ced stiffness of Buildings C-331 and C-335 following completion of the seismic modifications may increase the number and the probability of seismically-induced equipment failures inside the buildings.
However, the number and location of equipment failures that are predicted to occur based on the final design of the structural modifications are not significantly different from j
those currently identified in the SAR.
l The consequences of seismically-induced equipment failures following completion of the upgrades are bounded by the seismic failures evaluated in the JCO for Compliance Plan Issue 36. Four postulated seismic failure cases are evaluated in the JCO that predict uranium uptake and HF exposure to individuals (see Table 1 of Compliance Plan Issue 36). The bounding case assumes a complete building collapse and the release of the entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated consequences of the small number of equipment failures that are l predicted to result from the stiffening of Buildings C-331 and C-335.
b.
Issue 2 has been identified as a USQ because the process ofinstalling the new structural steel may make the building and contained equipment more susceptible to seismically-induced failure as the existing structural frames are altered and/or replaced. However, the potential increase in probability of failure is temporary and will only exist during installation of the modifications.
I l
I to GDP 97-0136 Page 3 of 5 Although the probability of seismically-induced building and equipment failures may be temporarily increased during the construction process, the consequences of these postulated failures are bounded by the seismic failures evaluated in the JCO for Compliance Plan Issue 36. Four postulated seismic failure cases are evaluated in the JC0 that predict uranium uptake and 11F exposure to individuals (see Table 1 of Compliance Plan issue 36). The bounding case assumes a complete building collapse and the release of the entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated conseq.iences of any building or equipment failures that may be predicted to result should a seismic event occur during construction activities.
In addition, the current restrictions on subatmospheric operation in Buildings C-331 and C-335 serve to further reduce any postulated releases during the construction period l
below those evaluated in Compliance Plan Issue 36.
c.
Issue 3 has been identified as a USQ because the process ofinstalling the new structural steel may temporarily increase the probability of equipment failures due to postulated load handling accidents during construction.
Ilowever, the potential increase in probability of failure is temporary and will only exist during installation of the modifications. Additionally, various controls will be applied to each lift associated with the seismic modifications to preclude the possiblity of an accidental load handling accident.
Although the probability of equipment failure as a result of a postulated load handling accident may be temporarily increased during the construction process, the consequences of these postulated failures are bounded by failures evaluated in the SAR and the JCO for Compliance Plan Issue 36. First, because the weight of each lift is significantly less than evaluated in SAR Section 4.3.2.1.1 (5 tons versus 33 tons), a postulated load handling accident would produce less damage to cascade equipment (e g., size of hole,-single versus multiple holes, etc.) than assumed by the accident analysis. Second, the JCO ior Compliance Plan issue 36 evaluates four postulated scismic failure cases that predict uranium uptake and HF exposure to individuals (see Table 1 of Compliance Plan issue 36). The bounding case assumes a complete building collapse and the release of the entire contents of the cascade system. The calculated consequences of this bounding case exceed the estimated consequences of any equipment failures that may be predicted to result due to a postulated load handling accident, in addition, the current restrictions on sum uspheric operation in Buildings C-331 and C-335 serve to further reduce any pc mN ed releases during the construction period below those evaluated in Compliance Plan issue 36.
d.
Extending the completion date for the seismic upgrades has no effect on the probability of a seismic event. Although Buildings C-331 and C-335 will remain in a weakened condition for a longer time, the consequences of postulated seismic failures of these buildings will be no greater than those previously evaluated in the JCO for Compliance Plan Issue 36. The compensatory measures will also remain in effect until completion of the modifications, j
- Enclosure 3 to GDP 97-0136
- Page 4 of 5 e,
There is no effect on the probability of a seismic event by removing the reference to evacuation as an alternative for protecting the safety of the general public. There is also no change in the consequences of the postulated seismic failures evaluated in the JCO for Compliance Plan issue 36 because sheltering affords equivalent protection to evacuation.
Also, the change does not prevent off-site authorities from ordering an evacuation of the public.
f.
There is no effect on the probability or consequences of a seismic event by the changes l
to Compliance Plan issue 36 to identify the completion of the fmal design of the structural l
modifications and to reference to the DOE LLNL seismic risk study. The DOE 1.LNL l
study provides further suppon of the conclusions of the Compliance Plan JCO.
l For these reasons, there will be no significant increase in the probability of occurrence or the consequences of previously evaluated accidents.
5.
No New or DifTerent Tyne of Accident The accident scenario related to this certificate amendent is a seismic event that results in a t
i release of UF from Buildings C-331 and C-335. No new or different type of accident has been identified.
6.
No Sienifican: Reduction in Margins of Safety This cenificate amendment request has no impact on the margins of safety as defined in the basis for any Technical Safety Requirement. Therefore, no significant reductions in margins of safety will result.
7.
No Significant Decrease in the Effectiveness of any Program or Plans Contained in the Certificate Anolication For the reasons discussed in the response to Item 1 above, there will be no significant decrease in the efTectiveness of any program or plan contained in Volume 3 of the Certification Application.
l 8.
The oronosed changes do not result in undue risk to 11 nublic health and safety. 2) common defense and security. and 3) the emironment l
l a.
As discussed in the response to Item 4, the three USQs and the extension of the completion date for the seismic upgrades to Buildings C-331 and C-335 will not result in j
a significant increase in the probability of occurrence of previously evaluated accidents.
Also, there will be no increase in the consequences of previously evaluated accidents and no new accidents have been identified. Thus, there will be no undue risk to public health and safety or to the environment. The USQs have no impact on common defense and security.
. to GDP 97-0136 Page 5 of 5 b.
Removing the reference to evacuation as an alternative for protecting the safety of the general public will not result in undue risk to public health and safety because sheltering provides equivalent protection and the ability of oft site authorities to order an evacuation of the public is not char.ged. Removing the reference to evacuation has no impact on common defense and security or the envYonment.
The changes to Compliance Plan issue 36 to identify the completion of the fmal design l
c.
of the structural modifications and to reference to the DOE LLNL seismic risk study will l
not result in undue risk to public health and safety, common defense and security, or the l
environment. In fact, the DOE LLNL study provides funher support of the conclusions l
of the Compliance Plan JCO.
l 9.
No Change in the Tynes or Significantincrease in the Amounts of Anv Efiluents that May be Released OfTsite As discussed in the response to Item 4, there will be no increase in the consequences of a postulated seismic event. Therefore, there will be no change in the typs or significant increase in the amounts of any eflluents that may be released offsite.
10.
No Significant Increase in Individual or Cumulative Occunational Radiation Exposure The three USQs, the extension of the completion date for the seismic upgrades, and the changes j
to Compliance Plan Issue 36 to identify the completion of the final design of the structural l
modifications and to include a reference to the DOE LLNL seismic risk study are related to an l
existing plan for a plant modification that is required by Compliance Plan Issue y No increases in individual or cumulative occupational radiation exposures are involved.
'lemoving the reference to evacuation as an alternative for protecting the safety of the general public following a seismic event is an issue that is only related to exposures resulting from a postulated accident. There is no impact on individual or cumulative occupational radiation exposures.
I 1.
No Sienificant Construction Imnact This change involves an existing plan for a plant modification and only changes the completion date of the project. Therefore, there is no significant construction impact.
12.
No Significant Increase in the Potential for Radiolonical or Chemical Conscauences trom Previousiv Analyzed Accidents As discussed in the response to item 4, there is no significant increase in the probability of occurrence of previously evaluated accidents, Therefore, there is no significant increase in the potential for radiological or chemical consequences from previously analyzed accidents.
i
, to GDP 97-0136 Page1ofI COMMITMENTS CONTAINED IN Tills SU11MITTAl 1.
The fmal results of the resised equipment failure calculations are planned to be included ii.
USEC's October 31,1997 SAR Update required by Compliance Plan issuc 2, " Update the Application Safety Analysis Report." (Reference USEC Letter GDP 97-0121 dated July 18,1997.)
2.
Consistent with standard practice for upgrading structures, ten,porary supports or shoring will be used as required and the sequence of removal of old components and installation of new components will be selected based on the stability of the in-process structure. These standard practice techniques account for static and construction-activity dynamic loading, but do not necessarily account for postulated seismic loading.
3.
The project plan for installation of the seismic upgrades in Buildings C-331 and C-335 identifies the need for approximately 2300 lifts of structural steel shapes and related materials in each l
building.
l l
4.
The lins will be hand-nigged (i.e., no crane will be used) and involve structural steel shapes with a length between 20 and 50 feet, weighing less than 5 tons.
i 5.
The following controls will be applied to each lin associated with the seismic modifications:
Lift time will be minimized to reduce exposure to drop hazards.
Subatmospheric pressures will be maintained within the cascade process equipment.
Lin plans will be prepared and approved in accordance with plant procedures.
Each lia plan willinclude step-by-step instructions along with appropriate witness and/or inspection hold points.
The lift will be planned from initial rigging, to lift placement, stabilization, and rigging removal. Planning for each lin will include an identification of actions that would be taken in response to a hypotheticalload Landling accident.
A construction engineer will be assigned to provide dedicated oversight.
)
6.
In addition to the controls fer each lin described above, the following supplemental controls will be applied for each lift that is over, or in proximity to, operating Q or AQ equipment:
Facility owners will be notified prior to the lift An Operations representative will witness the lin and will maintain voice contact with the facility Area Control Room (ACR) throughout the lift to ensure that the ACR is notified as quickly as possible should a load handling accident occur.
I 1