ML20236S849
| ML20236S849 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant, Paducah Gaseous Diffusion Plant |
| Issue date: | 07/20/1998 |
| From: | Toelle S UNITED STATES ENRICHMENT CORP. (USEC) |
| To: | Knapp M NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM), NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| GDP-98-0140, GDP-98-140, TAC-L32043, TAC-L32044, NUDOCS 9807270262 | |
| Download: ML20236S849 (29) | |
Text
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. A cros.i so.rsj comp.ny July 20,1998 GDP 98-0140 Dr. Malcolm R. Knapp Acting Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk United States Nuclear Regulatory Commission Washington, DC 20555-0001 Paducah Gaseous Diffusion Plant (PGDP)
. Portsmouth Gaseous Diffusion Plara (PORTS)
Docket Nos. 70-7001 & 70-7002 Response to NRC Request for AdditionalInformation (TAC NOS. L32043 & L32044) i
Dear Dr. Knapp:
I By letter dated June 1,1998 (see the reference), the U.S. Nuclear Regulatory Commission (NRC) forwarded to the United States Enrichment Corporation (USEC) various questions on the certificate amendment requests to Update the Application Safety Analysis Reports (SARUP) for the Paducah, Kentucky and Portsmouth, Ohio gaseous diffusion plants.
USEC's responses to a number of the NRC questions / comments from the June 1,1998 letter are enclosed. Enclosure 1 provides a status of the response to each of the NRC questions / comments on the SARUP submittals. Responses to the remaining questions / comments will be submitted at a later date.
If you have any questions on USEC's responses, please call me at (301) 564-3250 or Steve Routh at (301) 564-3251. Enclosure 2 identifies new commitments contained in this submittal.
Sincerely, l
5,D.Redh fg Steven A.Toelle i
Nuclear Regulatory Assurance and Po!!cy Manager
Reference:
Letter from Charles Cox (NRC) to Mr. James H. Miller (USEC), "Paducah and Portsmouth Certificate Amendment Requests-Update of the Application Safety Analysis Reports (TAC Nos. L32044 & L32043)," dated June 1,1998.
9007270262 980720 PDR ADOCK 07007001 0
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.,~ p vrive, Bethesda, MD 20817-1818
' ~ y., V " '3 Telephone 301-564-3200 Fax 301-564 3201 http://www.usec.com Omces in Livermore. CA Paducah, KY Portsmouth, OH Washington. DC gd 2 2 M w_ __ - _-_ - _ _ _ _ -
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l Dr. Malcolm R. Knapp July 20,199,8 GDP.98-0140, Page 2 i
Enclosures:
- 1. Status of Responses to NRC Questions / Comments on SARUP
- 2. Commitments Contained in this Submittal i
cc: Mr. Robert C. Pierson, NRC-HQ l
NRC RegionIII
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NRC Resident Inspector-PGDP NRC Resident Inspector-PORTS Mr. Randall M. DeVault (DOE) i 4
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GDP 98-0140 STATUS OF RESPONSES TO Page 1 of 2 NRC QUESTIONS / COMMENTS ON SARUP 1.
2/5/98 NRC Questions Letter from Robert C. Pierson (NRC) to Mr. James H. Miller (USEC), "Paducah Certificate Amendment Request - Update of the Application Safety Analysis Report-(TAC NO.
L32043)," dated February 5,1998.
Submitted 2/27/98:
Q1,Q2,Q3,Q4 Working:
None 2,
2/25/98 NRC Questinns Letter from Charles Cox (NRC) to Mr. James H. Miller (USEC), "Paducah and Portsmouth Certificate Amendment Requests-Update of the Application Safety Analysis Reports (TAC Nos. L32043 & L32044)," dated February 25,1998.
Submitted 3/27/98:
~Q4,Q8,Q10,Q11,Q12,Q13,Ql4,Q15,Q19 Submitted 4/21/98:
Ql,Q2,Q3,Q5,Q6,Q7,Q9,Q16,Q18 Submitted 5/1/98:
Q17 Working:
None 3.
6/1/98 NRC Questions Letter from Charles Cox (NRC) to Mr. James H. Miller (USEC), "Paducah and Portsmouth Certificate Amendment Requests-Update of the Application Safety Analysis Reports (TAC Nos. L32044 & L32043)," dated June 1,1998.
Submitted 7/20/98:
Ch 2: Q1 Ch3: Q4(a, f), Q5, Q6(a, g), Q7(a, d), Q8, Q9, Ql 1(a, b), Q12, Q16(a, b), Q17(a, b), Q l 8(a, b), Q22(c), Q24(a, g)
Ch 4: Q2,QS Working:
Ch 3: Q1-Q3, Q4(b-e), Q6(b-f, h), Q7(b, c), Q10, Q11(c-f), Q13, Q14, Q15, Q16(c-f), Q17(c, d), Q18(c, d), Q19-Q21, Q22(a, b, d-f), Q23, Q24(b-f), Q25-Q35, Q37 l
Ch 4: Q1, Q3, Q4, Q6-21
]
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GDP 98-0140 STATUS OF RESPONSES TO Page 2 of 2 NRC QUESTIONS / COMMENTS ON SARUP '
4, 7/9/98 NRC Questions Letter from Charles Cox (NRC) to Mr. James H. Miller (USEC), "Paducah and Portsmouth Certificate Amendment Requests-Update of the Application Safety Analysis Reports (TAC Nos. L32044 & L32043)," dated July 9,1998.
l Working:
Ch1: Q1 l
Ch 3: Ql,Q2 Ch 4: Ql,Q2 TSR: Q1 - Q130
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5.
7/14/98 NRC Questions l
Letter from Charles Cox (NRC) to Mr. James H. Miller (USEC), "Paducah and Ponsmouth
[
. Certificate Amendment Requests-Update ofthe Application Safety Analysis Reports (TAC Nos. L32044 & L32043)," dated July 14,1998.
i Working:
Ql - Q15
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GDP 98-0140 Page1ofI Commitments Contained in This Submittal 1.
' Response to Chapter 3 - Q4 (NRC 6/1/98 Letter). The fourth paragraph under
" Qualitative fault tree analysis"in PORTS SARUP Section 3.8.2.1.3 will be revised to read as follows:
" problems in the cascade. This is because the reaction products, HF and UO F,
2 would be a small quantity relative to the normal cascade feed rates and interstage l~
flows. Therefore, no corrective actions are necessary."
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SARUP Q&R - PGDP/ PORTS July 20,1998 l
Chapter 2 - Q1 (NRC 6/1/98 Letter)
PGDP/ PORTS - General On page 2.4-8: the SARUP indicates cooling water supply to the enrichment cascades can be affected under extreme flood conditions, but this would not result in a release of uranium hexafluoride.
h This would seem to impact the cooling of the freon, which might result in higher freon pressures and a potential leak into the cascade, overpressurization, and uramum leakage. While floods are not prompt events, the SARUP should clarify the potential impact of floods and estimate the frequency.
Response
For PORTS, as noted in SARUP Section 2.4.3.2, the supply of cell cooling water could only be interrupted under extreme flooding conditions (PMF) since the pumps are designed to operate underwater.
For PGDP, although not specifically mentioned in SARUP, the raw water supply could also be interrupted during extreme flooding conditions. The loss of raw water would not directly result in any UF release.
6 Both sites have procedures which specify appropriate response actions in the event of a loss of raw water supply. The cooling tower basins contain a sufficient supply of cooling water to allow for 3 5 days of normal cascade operation without makeup water. This period of operation can be extended by reducing 1
plant power levels. As a result, there would be adequate time to take actions to prevent overheating of the cascade cells leading to a potential UF. release.
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 -Q4 (NRC 6/1/98 Letter)
PGDP/ PORTS - i3.8/3.15.2.1 The description should include a diagram identifying the valves and other key components.
a.
b.
The text should explain the temperatures and pressures and the bases behind them - for example, if the autoclave pressure limit is 15 psig, then the text should explain why considerably higher steam pressures (60 and 100 psig are mentioned elsewhere in the text; these have temperatures of 308 and 338 F, respectively) are being used; the starting j
temperatures of 225 and 240 F also need explanation; and the text should explain why 15 l
psig (250 F) steam is not used.
c.
The text should identify the normal and high levels for condensate in the autoclave, and use whichever bounds the analysis (i.e., potential for greatest impact).
d.
The valve arrangements on page 3.8-4 need a clearer explanation; it is not usual practice to have a mpture disk and a relief valve in series. Also, the text should explain how debris from a rupture disk impacts the operation of the relief valve, and identify the destination (s) of the reliefline (i.e., discharge to a room, scrubber).
The statement on page 3.8-4. "No corrective action is necessary because multiple failures e.
are required for a release..." should be clarified and supported with numerical analysis showing that the possibility of the (now mitigated) synem not performing its safety function is incredible (less than IE-6).
f.
The text notes loss of power / plant air events resulting in failure of the feed control valve to close and isolate, allowing the potential for reaction products to enter the cascade. This should be explained better, and the rationale for it not being categorized as a safety hazard substantiated.
g.
The potential effects ofloss of power and plant air should be discussed.
Response
i a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be l
included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
l b.
A response to this question will be provided at a later date.
c.
A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
j e.
A response to this question will be provided at a later date.
f.
This question is applicable to PORTS only. The following words will be added to the paragraph in question to clarify the explanation:
l "This is because the reaction products. HF and UO:F, would be a small 2
quantity relative to the normal cascade feed rates and interstage flows."
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SARUP Q&R - PGDP/ PORTS July 20,1998
' The maximum quantity of reaction products, utilizing the steam / condensate quantities available in the autoclave, would amount to approximately 800 lbs of UO:F and 200 lbs 2
of HF (SARUP Section 4.3.2.2.14) as compared to a nominal feed rate of 30,000-70,000 lbs per day and an interstage flow rate of 5,000-15,000 lbs per minute (rates dependent on power levels; see SAR Figure 3.1.1.1-5 for rates at 2260 MW). The HF would simply move up the cascade and the UO F would potentially deposit on equipment with some 22 potential operational problems from plugging (although most would deposit as a thin fihn on the inside of the feed piping). With the feed enrichments, ther. would be no criticality issues.
g.
A response to this question will be provided at a later date.
SARUP Revision:
a.
No revision required.
f.
The fourth paragraph under " Qualitative fault tree analysis" in PORTS SARUP Section 3.8.2.1.3 will be revised to read as follows:
... problems in the cascade. This is because the reaction products HF and UO F, would be a small quantity relative to the normal cascade feed 22 rates and interstage flows.
Therefore, no corrective actions are necessary."
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SARUP Q&R - PGDP/ PORTS July 20,1998 i
Chapter 3 - Q5 (NRC 6/1/98 Letter)
PGDP/ PORTS - g3.8/3.15.2.2 The description should include a diagram identifying valves and other key components.
a.
b.
The basis for the 30 second activation time requirement should be provided.
c.
The presence or absence of sensors for releases should be clarified, d.
The system is noted as not being independent of the 120 VAC power supply - this should j
be explained as 120 VAC independence is a functional requirement.
The text should clarify if there are sensors and controls that automatically trigger the I
c.
system upon detection of releases.
f.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function is incredible (less than IE-6).
Response
i a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to suppon SARUP Section 3.8/3.15, the SARUP l
Chapter 4 accident analysis, and the SARUP TSRs.
j b.
The functional requirement for isolation of autoclave active valves within 30 seconds from detection of a release is based on the following:
SARUP Section 4.3.2.2.10 assumes a release duration of 45 seconds. The 45 seconds covers the time from the start of the release until system isolation to stop the release.
Operator detection of a release and manual action to initiate isolation is assumed to occur within 15 seconds or less. A 15-second operator action time is justified because: (1) an operator is present during the feeding of cylinders; (2) any release would be quicidy detected by an operator through the visual indication of a " white smoke" (i.e., reaction products of UF. and moisture) or the odor of HF, which is a product of the reaction of UF. and moisture; and (3) remote switches for system actuation are located where operator action can be accomplished upon evacuation of the facility.
At each plant, valve testing has shown actual closure times to be 30 seconds or less.
Also, it is important to note that. in SARUP Section 4.3.2.2.10, based on the assumed 45 second release duration, there is significant margin in the source term analysis relative s meeting the EGs.
c.
Operation of the remote feed isolation system is manually initiated. Manual initiation of the system by an operator is based on detection of a release through one of two ess;ntial methods: (1) visual indication of a " white smoke" (i.e., reaction products of UF and i
moisture), or (2) the odor of HF, which is a product of the reaction of UF. and moisture.
Because of the presence of operators during the feeding of cylinders, SARUP Section 1 of 2 E----.---_____
SARUP Q&R - PGDP/ PORTS July 20,1998 4.3.2.2.10 does not credit the UF. detection system in the feed facilities to assist the-operator in detection of a release, d.
For PGDP, the remote feed isolation system fails in a safe position; upon loss of 120 VAC power, the isolation valves on the feed autoclaves will automatically close.
For PORTS, upon loss of 120 VAC power, the isolation valves on the feed autoclaves will automatically close with the exception of the "F" valve located in the feed line of each autoclave which will fail as-is (see SARUP Table 3.8-1). This condition is being corrected as part of Item 2 of the Plan of Action and Schedule for Compliance Plan Issue 3 (see Table 1, Item 12, of Enclosure 1 to USEC letter GDP 97-0189 dated October 31,1997).
1 As discussed in the response to part c. of this question, the remote feed isolation system c.
is not automatically initiated.
l f.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than 1E-6).
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q6 (NRC 6/1/98 Letter)
PGDP/ PORTS - 93.8/3.15.2.3 The description should include a diagram identifying key components.
a.
b.
The valving and its arrangement should be explained.
The steam pressures should be explained, including the basis for limiting it to 60 psig.
c.
The volume of steam should also be identified.
d.
The text should describe the autoclave in more detail, including the basis for the condensable level used in the analysis (i.e., does it correspond to the high limit) and the associated mass of water.
A calculation should be provided showing the expected pressure rise from the uranium e.
hexafluoride/ water reaction.
f.
The use of 90 psig test pressures for periodic leak testing should be explained given an autoclave pressure limit of 15 psig. Also, typical actual versus allowable leak rates should be noted. A 12 SCFM allowable leak rate seems rather high and should be explained.
g.
A numerical analysis should be included demonstrating that the probability (now mitigated) of the system not performing its safety function is incredible (less than IE-6).
h.
Explain the use for the 2.5 ton cylinder as the limiting case since the 14 ton cylinder is used in Chapter 4.
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A response to this question will be provided at a later date.
c.
A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
e.
A response to this question will be provided at a later date.
f.
A response to this question will be provided at a later date.
g.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria 1 of 2 1
L___________________.
SARUP Q&R - PGDP/ PORTS July 20,1998 in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
h.
A response to this question will be provided at a later date.
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 s Q7 (NRC 6/1/98 Letter)
PGDP/ PORTS - Q3.8/3.15.2.4 The description should include a diagram identifying key components.
a.
b.
The type, functions, and ranges of the pressure / flow reducing devices should be explained.
The text should clarify the basis for categorizing the system as Q and AQ, depending upon c.
the location with respect to the isolation valves; it is not apparent how the isolation valves would inhibit liquid UF. flow if both valves are open (which would be the case during normal operations).
d.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function is incredible (less than IE-6).
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A response to this question will be provided at a later date.
c.
A response to this question will be provided at a later date, d.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
l SARUP Revision:
No revision required.
SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3.Q8 (NRC 6/1/98 Letter)
PGDP/ PORTS - 63.8/3.15.2.5 The description should include a diagram identifying key components, a.
b.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function is incredible (less than IE-6).
c.
This system has two safety functions, NCS and personnel protection. While it may be considered to preserve initial conditions in an accident analysis, more justification is needed to explain why this system is not considered as a system to prevent or mitigate an accident since the water inventory does provide a mitigation factor for the pressure inside of the autoclave during the scenario and therefore would warrant a Q categorization.
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than 1E-6).
A c.
The amount of water in the autoclave does not initiate any accident sequence nor does it act to mitigate an accident once one occurs. The modeling of the autoclave release pressure transient was based on the steam within the autoclave and the condensate on surfaces accessible to the postulated UF. release; the assumption was that the water in the l
drain line was maintained below the autoclave level by this system. The model assumed instantaneous reaction of the steam / condensate with UF. as it is released. thus providing a bounding analysis. A higher or lower water level in the drain pipe would not affect the l
overall pressure transiem. Consequently. the autoclave water inventory control system l
(PGDP)/ autoclave high condensate level cutoff system (PORTS) does not satisfy the Q l
classification criteria in SARUP Section 4.2.2.
l The autoclave water inventory control system (PGDP)/ autoclave high condensate level cutoff system (PORTS) is credited in SARUP Section 3.8.2.5.4/3.15.2.5.4 with establishing an initial condition for the accident analysis and for providing a nuclear criticality safety active engineered feature (NCS AEF). Consequently, the system is 1
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i SARUP Q&R - PGDP/ PORTS July 20,1998 classified as AQ-NCS in SARUP Table 3.8-3/3.15-3 in accordance with the AQ classification criteria in SARUP Section 4.2.2.
i 3ARUP Revision:
l No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q9 (NRC 6/1/98 Letter)
PGDP/ PORTS - 53.8/3.15.2.6 This system has a safety function to ensure a cylinder is not overheated and hydraulically rupture.
Preserving initial conditions appears to be a narrow approach to this SSC's safety function. Using this logic, a reactor overpower trip could be considered preserving initial conditions of the accident analysis and need not be a Q system. The high pressure steam cutoff prevents overheating a cylinder causing a hydraulic rupture, an active system that prevents an accident. Provide further justification why this should not be a Q system.
Response
The autoclave high pressure isolat on system (PGDP)/ autoclave shell high pressure containment i
shutdown system (PORTS) is the Q syste:u credited with providing protection in the event of a cylinder rupture inside the autoclave [see SARUP Sections 4.3.2.2.13, 14, 3.8.2.1/3.15.2.1, and TSR 2.2.3.1 (Modes IV, V, VI, and VII)]. While the operation of the high cylinder pressure system (PGDP)/UF.
cylinder high pressure steam cutoff system (PORTS) would prevent the overheating and hydraulic rupture of a cylinder, the autoclave high pressure isolation system (PGDP)/ autoclave shell high pressure containment shutdown system (PORTS) is credited in the SARUP for preventing a cylinder hydraulic rupture due to addition of heat from steam (with the exception of the controlled feeding mode). As described in SARUP Sections 3.8.2.6/3.15.2.6, the high cylinder pressure system (PGDP)/UF. cylinder high pressure steam cutoff system (PORTS) preserves the initial condition (maintains UF. in solid state) for the controlled feeding mode. In addition, as described in SARUP Sections 4.3.2.2.6,7, and 9, the high cylinder pressure system (PGDP)/UF. cylinder high pressure steam cutoff system (PORTS) is available during the heating mode of operation to detect high cylinder pressures and isolate the steam supply to stop the event prior to primary system rupture and minimize the potential for onsite personnel exposure to releases of material. As such, the high cylinder pressure system (PGDP)/UF. cylinder high pressure steam cutoff system (PORTS) is appropriately classified as AQ in accordance with the criteria in SARUP Section 4.2.2.
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q11 (NRC 6/1/98 Letter)
PGDP/ PORTS - Q3.8.2.8 The description should include a diagram identifying key components.
a.
b.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function is incredible (less dan IE-6).
The description. should explain terminology and location of sensors; ambiguous terms c.
include actuation pressure and emergency autoclave operation switch.
d.
The inter-operability between bis system, the emergency autoclave bypass switch, and the autoclave shell high pressure containment system should be explained better.
It is not clear how this system can receive an AQ designation, as it complements a Q e.
system and prevents the potential for significant offsite effects (i.e., a Q system requirement); the AQ designation should be explained.
f.
Information should be provided to explain how this unit functiors without electrical power, as stated in the functional requirements.
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform 6eir safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
c.
A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
e.
A response to this question will be provided at a later date.
f.
A response to this question will be provided at a later date.
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q12 (NRC 6/1/98 Letter)
PGDP/ PORTS - f 3.8/3.15.2.1 - 3.8/3.15.2.8 The discussion about autoclave systems should explain how the different safety categories will be maintained on what is essentially the same SSC. Also, the contractor may wish to discuss the relative merits of a uniform categorization for the autoclave as compared to a piecemeal approach.
Response
The Application (in particular, SAR Chapters 5 and 6 and the Quality Assurance Program Description) describes the various programmatic controls and requirements applicable to Q, AQ, and AQ-NCS SSCs. These controls and requirements are implemented in policies and procedures at the plants.
The Q, AQ, and AQ-NCS boundaries of SSCs are defined in SAR/SARUP Sections 3.8 (PORTS) and 3.15 (PGDP) and in the Boundary Definition Manuals for each plant to ensure the appropriate controls and requirements are consistently applied.
SARUP Revision:
No revision required.
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SARUP Q&R - PGDP/ PORTS July 20,1998
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Chapter 3.Q16 (NRC 6/1/98 Letter)
PGDP/ PORTS - 93.8/3.15.3.4 l.
The description should include a diagram identifying key components, locations, power a.
supply systems, control power supply, etc.
b.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function it, incredible (less than IE-6).
Numerical values should be provided for the system pressures and the relief valve / rupture c.
disk settings. These should include normal pressure, MAWP, failure pressure (estimated),
and relief set points.
d.
A lock-out/ tag-out program should be identified for those relief valves / rupture disks that are separated from the coolant system by a manual block valve.
The description of the freezer / sublimer systems contains several apparent discrepancies e.
that should be clarified. Also, a numerical analysis should be presented showing the source term form potential events.
f.
The destination of the downstream piping from the relief devices should be identified (i.e.,
relief to the roof, to a scrubber).
Response
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be a.
included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requiremer/s to provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
c.
A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
1 e.
A response to this question will be provided at a later date.
l f.
A response to this question will be provided at a later date.
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SARUP Q&R - PGDP/ PORTS July 20,1998 SARUP Revision:
No revisica required.
1 4
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q17 (NRC 6/1/98 Letter) t l
PGDP/ PORTS - 53.8/3.15.3.5 '
- a.
The description should include a diagram identifying key components, locations, power L
supply systems, control power supply, etc.
b.
A numerical analysis should be included demonstrating that the probability of the (now l
mitigated) system not performing its safety function is incredible (less than IE-6).
c.
The number of these systems should be identified.
l d.
- The total volume and weight of these systems should be ideadfied.
Response
L a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagran.s will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.'
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any panicular failure frequency. The capability of SSCs to perform their l:
safety function was determined in the SARUP based on engineering analyses, engineering l'
judgement, and plant operating history (supplemented in some cases with qualitative fault l
tree analyses). This process identified the SSC quality and operability requirements to l'
. provide adequate assurance that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2.' There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing
' its safety function is incredible (less than IE-6).
c.
A response to this question will be provided at a later date.
~ d.
A response to this question will be provided at a later date.
SARUP Revision:
/-
No revision required.
l-p 1
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3 - Q18 (NRC 6/1/98 Letter)
PGDP/ PORTS - !3.8/3.15.3.6 j
The description should include a diagram identifying key components, locations, power a.
supply systems, control power supply, etc.
b.
A numerical analysis should be included demonstrating that the probability of the (now mitigated) system not performing its safety function is incredible (less than 1E-6).
c.
There should be a better explanation of the ammeter indications and the operator response to/ investigation of " inexplicable change".
d.
It would seem that the motor load indicators are essential for detecting and avoiding compressor surge events, precursors to releases producing off-site effects. Consequently, the text should explain the basis for an "AQ" designation instead of a "Q" designation.
j
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.
b.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perfonn their safety function was determined in the SARUP based on engineering analyses, engineering i
judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurara that the SSC could be expected to perform its safety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
c, A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
ld SARUP Revision:
No revision required.
l
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i SARUP Q&R - PGDP/ PORTS July 20,1998 i
Chapter 3 - Q22 (NRC 6/1/98 Letter)
PGDP/ PORTS - 13.8/3.15.5.1 a.
The analysis should provide more information and numerical values on the intermediate calculations supporting the conclusions of adequate temperature control and cylinder ullage space. This additional information should show the enthalpy calculations and assumed volumes of materials.
b.
There should be an explanation for the use of high pressure steam (>250 F/15 psig) that exceeds the pressure limit settings, and the reasons for not using amore passive system (steam < 250 F/15 psig, or even steam with conditions below the zero ullage temperature of the cylinder) included. The text should also clarify the actual steam pressures used in the calculations (60 or 100 psig) and if intermediate pressures (say, in the 15-100 or 15-60 psig ranges) represent a greater potential hazard because of a longer time period (for heating) prior to reaching the autoclave pressure limit of 15 psig.
A probability analysis should be presented to support the conclusion of meeting its safety c.
function requirement.
d.
The text should clarify (by calculation) that a cylinder failure event does not result in excessive pressures and leakage from the autoclave, due to the cylinder's pressure and hydrolysis reactions.
The reliability of the pressure relief lines should be based upon probability calculations, e.
and numerical values provided.
f.
As noted in the text, the loss of power operability of the isolation valves and positive indications of position need to be established.
Response
a.
A response to this question will be provided at a later date.
b.
A response to this question will be provided at a later date.
c.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operatiag history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its sefety function.
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria in the SARUP analyses for demonstrating that the probability of a system not performing l
its safety function is incredible (less than IE-6).
d.
A response to this question will be provided at a laier date.
I c.
A response to this question will be provided at a later date.
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l
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'SARUP Q&R - PGDP/ PORTS July 20,1998 f.
A response to this question will be provided at a later date.
SARUP Revkion:
. No revision required.'
l l-l l
t c.
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SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 3.- Q24 (NRC 6/1/98 Letter)
PGDP/ PORTS - 53.8/3.15.5.3 L
a.
The description should include a diagram identifying key components.
k b.
The valving and its arrangement should be explained.
The steam pressures should be explained, including the basis for limiting it to 60 psig at c.
- Portsmouth., The volume of steam should also be identified.
d.
The text should describe the autoclave in more detail, including the basis for the condensate level used in the analysis (i.e., does it correspond to the high limit) and the associated mass of water, A calculation should be provided showing the expected pressure rise from the uranium e.
i hexafluoride/ water reaction.
f.
The use of 90 psig test pressures for periodic leak testing should be explained given an autoclave pressure limit of 15 psig. Also, typical actual versus allowable leak rates should be noted.
g.
A numerical analysis should be included demonstrating that the probability (now mitigated) l of the system not performing its safety function is incredible (less than IE-6).
Response
a.
Current SAR Chapter 3 provides diagrams for various SSCs. Diagrams will also be included in the rewrite of SAR Chapter 3 to support SARUP Section 3.8/3.15, the SARUP Chapter 4 accident analysis, and the SARUP TSRs.-
b.
A response to this question will be prov'ded at a later date.
c.
A response to this question will be provided at a later date.
d.
A response to this question will be provided at a later date.
e.
A response to this question will be provided at a later date.
f.
A response to this question will be provided at a later date.
g.
A numerical analysis was not performed to demonstrate that the system would perform its safety function at any particular failure frequency. The capability of SSCs to perform their safety function was determined in the SARUP based on engineering analyses, engineering judgement, and plant operating history (supplemented in some cases with qualitative fault tree analyses). This process identified the SSC quality and operability requirements to provide adequate assurance that the SSC could be expected to perform its safety function.-
The process used in the SARUP is consistent with the approach described in Section 1.d of the Plan of Action and Schedule for Compliance Plan Issue 2. There were no criteria j
in the SARUP analyses for demonstrating that the probability of a system not performing its safety function is incredible (less than IE-6).
4-1 of 2
SARUP Q&R - PGDP/ PORTS July 20,1998 SARUP Revision:
No revision required.
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' SARUP Q&R - PGDP/ PORTS July 20,1998 Chapter 4 - Q2 (NRC 6/1/98 Letter)
PGDP/ PORTS - Chapter 4. General The discussion of the accident scenarios mixes mitigated and unmitigated approaches, particularly in the discussion on accident frequencies and the evaluation guideline bins. It is recommended that the scenario development clearly focuses on unmitigated consequences first, before applying the effects of mitigation upor. the scenario.
Response
The Chapter 4 accident scenarios are developed as this question suggests. Each scenario provides a description of the scenario progression, followed by a statement of the unmitigated consequences as determined in the PrHA, followed by a discussion of the mitigative actions / controls needed to bring the unmitigated consequences within EGs (where possible). For example, refer to SARUP Section 4.3.2.1.1.
In subsection 4.3.2.1.1.a,." Scenario Description," the first 4 paragraphs describe the scenario, the fifth paragraph describes the potential consequences if unmitigated, and the remainder of the subsection r
describes the safety controls to prevent the accident and the safety actions required to mitigate the consequences if the preventive controls fail. Subsection 4.3.2.1.1.c, " Consequence Analysis," describes the safety controls relied upon to meet the safety actions associated with event mitigation for the various receptors of concern.
1 SARUP Revision:
f No revision required.
1
c SARUP Q&R - PGDP/ PORTS July 20,1998 i
Chapter 4.Q5 (NRC 6/1/98 Letter) 1 PGDP/ PORTS - General The accident analyses do not always clearly state the material at risk, and, in some cases, appear
- to truncate the release even when there is material remainmg. Sometimes, the thermodynamic properties of uranium hexafluoride are used to justify a termmation point after the vapor pressure of the hexafluoride material falls below atmospheric pressure. However, materials may continue to be released. De SARUP's should revise the analyses to include these additional amounts in the material at risk calculations.
- Response:
Where the thermodynamics of the system show that the release of UF. will essentially stop, this was included in the development of the source term. The remaining material was determined to not be "at risk" in the analysis of accident consequences. While some additional UF. could be released in small.
quantities over long periods, this material would not contribute appreciably to the predicted accident consequences since it would not approach the maximum concentrations used for determining potential
. consequences. In those cases where additional amounts of material would contribute to the source term and consequences, these quantities were included. The potential for the accumulation of radiation dose is not a concern because the predicted radiation exposures from postulated accidents involving the release of UF. at the GDPs do not approach significant levels.
SARUP Revision:
No revision required.
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GDP 98-0140 L
Page1of1 Commitments Contained in This Submittal 1.
Response to Chapter 3 - Q4 (NRC 6/1/98 Letter). The fourth paragraph under
" Qualitative fault tree analysis"in PORTS SARUP Section 3.8.2.1.3 will be revised to read as follows-I l
~
2'... problems in the cascade. This is because the reaction products, HF and UO:F,
2 would be a small quantity relative to the nonnal cascade feed rates and interstage flows. Therefore, no corrective actio'is are necessary."
p.