ML20151K078
| ML20151K078 | |
| Person / Time | |
|---|---|
| Site: | Portsmouth Gaseous Diffusion Plant |
| Issue date: | 07/30/1997 |
| 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) |
| References | |
| GDP-97-0128, GDP-97-128, NUDOCS 9708050330 | |
| Download: ML20151K078 (20) | |
Text
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United StitIs EnrichmInt Corporition 2 Democricy C;ntIr 6903 Rockledge Drive Bethesda, MD 2081r Tel: (301)S64-3200 Fax:(301) 564-3201 JAMES H. MILLEn Dir. (301) 564-3309 VICE PRESIDENT, PRODUCTION Fax: (301) 571-8279 July 30,1997 Dr. Carl J. Paperiello SERIAL: GDP 97-0128 Director, Office of Nuclear Material Safety and Safeguards Attention: Document Control Desk U.S. Nuclear Regulatory Commission Washington, D.C. 20555-0001 Portsmouth Gaseous Diffusion Plant (PORTS)
Docket No. 70-7002 Certificate Amendment Request-TSR Section 2.1.3.11-Autoclave Smoke Detection System
Dear Dr. Paperiello:
In accordance with 10 CFR 76.45, the United States Enrichment Corporation (USEC or Corporation) hereby submits a request for amendment to the certificate of compliance for the Portsmouth, Ohio Gaseous Diffusion Plant (GDP). This certificate amendment request revises Technical Safety Requirement (TSR) 2.1.3.11, Autoclave Smoke Detection System, to clarify the requirements for operable smoke detectors required during operations.
The existing TSR Limiting Condition for Operation (LCO) requires that 50% of the installed autoclave UF smoke detection heads in a facility shall be operable. However, the number of smoke detection heads specified in the Condition A of TSR 2.1.3.11 for each facility does not represent 50%
of the installed smoke detectors in all cases. Furthermore, the existing TSR does not specify which of the installed smoke detector heads within a facility are required to be operable for operation of a specific autoclave. In addition, a change to the Basis Statement for TSR 2.1.3.11 is proposed which clarifies the smoke watch requirements for the X-343 building. This clarification specifies that only one smoke watch is required for the X-343 building regardless of the number of smoke detectors that are inoperable, i
hD 9708050330 970730 PDR ADOCK 07007002 C
PDR Offices in Livermore, California Paducah, Kentucky Portsmouth. Ohio Washington, DC
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u-j Dr. Carl J. Paperiello July 30,1997 GDP 97-0128 Page 2 j
Enclosure I to this letter provides a detailed description and justification for the proposed change. is a copy of the revised TSR and SAR pages. The TSR pages are provided for your
. review and approval. The SAR pages have been evaluated in accordance with 10 CFR 76.68. Based i
on the'results of the 10 CFR 76.68 evaluation, the enclosed SAR pages do not require prior NRC
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review and approval and are provided for information only. These revised SAR pages reflect revisions associated with this certificate amendment request and may not reflect other approved changes to these SAR pages. Enclosure 3 contains the basis for USEC's' determination that the i
proposed changes associated with this certificate amendment request are not significant.
Since this proposed certificate amendment request is not required to support continued operation, USEC requests NRC review and approval at your earliest convenience. The amendment should become effective 30 days from issuance.
I Any questions related to this subject should be directed to Mr. Mark Smith at (301) 564-3244.
There are no new commitments contained in this submittal.
Sincerely, es H. Miller Vice President, Production
Enclosures:
As Stated cc:
NRC Region III Ofnce -
i NRC Resident Inspector - PGDP NRC Resident Inspector.- PORTS DOE Regulatory Oversight Manager
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OATH AND AFFIRMATION I, 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 Portsmouth Gaseous Diffusion Plant, that I am familiar with the contents thereof, and that the statements l
made and matters set forth therein are tme and correct to the best of my knowledge, information, and belief.
ames H. Miller On this 30th day of July,1997, the officer signing above personally appeared before me, is known by me to be the person whose name is subscribed to within the instrument, and l
acknowledged that he executed the same for the purposes therein contained.
In witness hereof I hereunto set my hand and official seal.
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LULAL b.
LL4A r
V ) ie M. Knisley, Notary Public Laur l
State of Maryland, Montgomery County l
. My commission expires March 17, 1998 i
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GDP97-0128 Page1 of4 United States Enrichment Corporation (USEC)
Proposed Certificate Amendment Request TSR Section 2.1.3.11-Autoclave Smoke Detection System Detailed Description of Change Specific TSR Sections Affected The proposed change is to revise the Technical Safety Requirements (TSR), Limiting Condition for Operations (LCO) 2.1.3.11, and associated Basis statement to clarify the requirements for operable smoke detectors required during autoclave operations; and to add system description information to the SAR. The specific changes to the TSRs include the following:
- revise the existing LCO statement from:
"50% of the installed Autoclave UF smoke detection heads in a facility shall be 6
operable" to:
" Autoclave UF smoke detection systems shall be operable."
6 delete the existing LCO condition A:
"A.
Smoke detectors operable:
X-344
<2 X-343
<4 X-342
< 2" and replace it with two conditions:
"A.
For the X-342 and X-344 buildings:
< 1 operable smoke detector alarm circuit covering the area above the autoclaves B.
For the X-343 building:
< 1 operable smoke detector alarm circuit covering the area above each autoclave pair (i.e., No. I and 2; 3 and 4; 5 and 6) and autoclave No. 7"
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I GD197-0128 Page 2 of 4 United States Enrichment Corporation (USEC)
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Proposed Certificate Amendment Request TSR Section 2.1.3.11-Autoclave Smoke Detection System Detailed Description of Change add the following to the end of the existing Basis statement:
"This LCO ensures that at least one smoke detector alarm circuit, covering the area above each autoclave that is not shutdown, is operable. For autoclaves in the X-343 building, an autoclave smoke detector alarm circuit is required to have at least one operable smoke detector head above each respective autoclave pair (i.e., autoclave No. I and 2; 3 and 4; 5 and 6) and above autoclave No. 7, in order to be considered operable. Furthermore, a single smoke watch is adequate to implement Action B.1 regardless of how many autoclaves may be affected. Because of the physical layout of the autoclaves and the smoke detector heads in the X-342 and X-344 buildings, an autoclave smoke detector alarm circuit in either of these two buildings is required to have both smoke detector heads operable in order to be considered operable. Other smoke detectors (and their associated alarm circuits) located in these facilities but not physically above the autoclaves are not covered by this TSR and shall not be used to satisfy the LCO requirements"
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Related SAR Changes (for information) 2 A new SAR section 3.2.1.1.6 will be added to read as follows:
"3.2.1.1.6 UF Leak Detection System The UF leak detection system in X-343 facility provides audible and visual alarms in 6
1 the event that a UF release occurs. Detectors are located over the autoclaves, on the Z-Header 6
2 catwalk, and on the ground floor between the control panels for autoclaves 4 and 5. The detectors are grouped into ten alarm circuits (also referred to as " zones") with two detectors in each circuit except for two zones covering autoclave No. 7 which have only one detector per circuit. Activation of a single detector will activate an audible and visual alarm at the system control panel. The alarm is intended to notify operators that a UF leak may have occurred in the building. Operators may disable individual alann circuits using switches located on the 3
panel."
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GDP97-0128 i
Page 3 of 4 l
United States Enrichment Corporation (USEC)
Proposed Certificate Amendment Request TSR Section 2.1.3.11-Autoclave Smoke Detection System Detailed Description of Change j
i
- A new SAR section 3.2.1.2.6 will be added to read as follows:
4 "3.2.1.2.6 UF Leak Detection System The UF leak detection system in X-342A facility provides audible and visual alarms in l
the event that a UF release occurs. Detectors are located over the autoclaves, over the HF storage room, and inside the HF storage room. The detectors are grouped into three alarm circuits (also referred to as " zones") with two detectors in each circuit. Activation of a single detector will activate an audible and visual alarm at the system control panel. The detectors over the autoclaves and their associated alarm circuits an: intended to notify operators that a UF leak
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6 may have occurred in the building. Operators may disable individual alarm circuits using I
switches located on the panel."
SAR section 3.2.1.3.6 will be revised by adding a new paragraph to read as follows:
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f "The UF leak detection system in X-344A facility provides audible and visual alarms in the
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event that a UF release occurs. Detectors are located in the north high bay over the autoclaves.
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The detectors are grouped into two alarm circuits (also referred to as " zones") with two detectors in each circuit. Activation of a single detector will activate an audible and visual alarm at the 4
i system control panel. The alarm is intended to notify operators that a UF. leak may have j
j occurred in the building. Operators may disable individual alarm circuits using switches located
)
on the panel."
Reason for Change i
The purpose of the change is to r.larify wording in the existing TSR that is confusing and misleading.
The current TSR LCO rcymres that "50%" of the installed autoclave UF. smoke detection heads shall be operable. However, the specific numbers provided for the autoclave facilities do not represent 50% in all cases. Furthermore, the TSR does not specify which smoke detector heads need to be operable for operation of a specific autoclave. Under the existing wording, smoke heads not above an operating autoclave would satisfy the LCO requirement when in fact they may not provide adequate detection and response capability because of their remoteness to the autoclave.
Justification for the Change SAR Section 4.2.3 discusses UF. releases involving feed, sampling, and transfer operations. For autoclave facilities, the accident scenarios where there is, generally, the greatest likelihood of a significant release rely on the presence and actions by operators conducting the evolution to mitigate i
any release. There is no mention of the actuation of smoke heads in these facilities to alert operators.
Nevertheless, the TSRs provide an LCO which currently requires 50% of the smoke heads in the
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1-GDP97-0128 Page 4 of 4
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United States Enrichment Corporation (USEC)
Proposed Certificate Amendment Request
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TSR Section 2.1.3.11-Autoclave Smoke Detection System Detailed Description of Change 1.
l autoclave facilities to be operable. The TSRs also provide specific actions if the level of operable detectors drops below given values. The given values, in the case of the X-343 facility, represent less than 50% (i.e., only 4 out of 14 installed detector heads above the autoclaves in X-343).
Furthermore, the existing TSR does not specify which smoke heads are required to be operable i-for which autoclaves. Therefore, the existing TSR LCO statement and the associated LCO l
conditions do not agree for the X-343 facility.
The changes to the TSR for the X-342 and X-344 facilities continue to require that at least two detector heads remain operable for autoclave operation (there are currently six detector heads in X-1 342 and four in X-344). However, the revised TSR specifies that the detectors required must be the I
detectors above the autoclaves, not other detectors that may also be in the building. The revised i-wording also clarifies two other issues by: referring to " smoke detector alarm circuit" instead ofjust i
the detectors; and requiring that all autoclaves in the building be shutdown if the minimum number
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of detectors are not operable.
The change to the TSR for the X-343 facility specifies which detectors are required to be operable by tieing the detectors to the respective autoclave. While the absolute minimum number of detector heads (4) under the revised TSR is the same as the existing TSR, the revised change would no longer permit taking credit for detector heads at one end of the building for autoclave operations at the other end of the building. Furthermore, each operable alarm circuit will normally have two operable detectors because one inoperable head will disable the entire circuit; unless the head is physically removed from the fixture which is not normally done. The one exception to this is the No. 7 autoclave which has two detector heads, each assigned to a separate alarm circuit.
One additional clarification to the Basis statement is to specify that only one smoke watch is required for the X-343 building regardless of how many autoclaves may be in the action statement. This statement is consistent with current TSR implementation practices and is included only for
' clarification. This statement was not considered necessary for the X-342 and X-344 facilities since
- it is implicit in the buildings' LCO action statement.
j Other smoke detectors and their associated alarm circuits located in these facilities but not physically j
above the autoclaves are not covered by this TSR and shall not be used to satisfy the LCO.
The addition of system description information to the SAR is necessary since the current SAR contains no such information regarding these systems other than the brief boundary description in section 3.8.2.
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GDP97-01-28 Page 1 of 9 i
Proposed Certificate Amendment Request Portsmouth Gaseous Diffusion Plant Letter GDP97-0128 Removal / Insertion Instructions l
Remove Page Insert Page VOLUME 1 Section 3.2 Section 3.2 Pages 3.2-15, 3.2-16, 3.2-17, 3.2-17a, 3.2-Pages 3.2-15, 3.2-16, 3.2-17, 3.2-17a, 3.2-17b, and 3.2-18 17b, and 3.2-18 VOLUME 4 Section 2.1.3.11 Section 2.1.3.11 Page 2.1-20 Pages 2.1-20 and 2.1-20a
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TSR-PORTS PROPOSED July 29,1997 RAC 97X0095 (RO) l SECTION.1 SPECIFIC TSRs FOR X-342, X-343, AND X-344 FACILITIES 2.1.3 LIMITING CONTROL SETTINGS, LIMITING CONDITIONS FOR OPERATION, SURVEILLANCES 2.1.3.11 Autoclave Smoke Detection System APPLICABILITY:
All Autoclave Operational Modes LCO:
Auto:: lave UF smoke detection systems shall be operable.
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i ACTIONS:
Note: TSR 1.6.2.2(d) does not apply Condition Required Actions Completion Time A. For the X-342 and X-344 A.1 Provide Inunediately l
buildings:
continuous l
smoke watch at l
< 1 operable smoke detector affected area l
alarm circuit covering the area OR l
above the autoclaves
^
A.2 Place all 1 Hour autoclaves in the l
affected building l
in Mode VII B. For the X-343 building:
B.1 Provide Immediately l
continuous l
< 1 operable smoke detector smoke watch at l
alarm circuit covering the area affected area l
above each autoclave pair (i.e.,
OR No. l and 2: 3 and 4: 5 and 6) autoclave (s) g a e aRecte 1 Hour and autoclave No. 7 in Mode VII l
2.1-20
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TSR-PORTS PROPOSED July 29,1997 RAC 97X0095 (RO)
SECTION 2.1 SPECIFIC TSRs FOR X-342, X-343, AND X-344 FACILITIES
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2.1.3 LIMITING CONTROL SETTINGS, LIMITING CONDITIONS FOR OPERATION, SURVEILLANCES 2.1.3.11 Autoclave Smoke Detection System (continued)
SURVEILLANCE REQUIREMENTS:
Frequency Surveillance Semiannually SR 2.1.3.11.1 Test active smoke heads to ensure alarm indication will occur when smoke head is exposed to a simulated smoke condition.
t BASIS:
1 In the event of a UF release in the autoclave area a local indicator will sound notifying 6
operating personnel that immediate investigation and action must occur. The smoke detection l
system and subsequent personnel actions will mitigate the consequences of any UF release.
6 The detection components used are ionization type fire detectors designed to detect not only i
smoke but invisible combustion products. Due to their opereing principle these detectors will also actuate in the presence of steam and vehicle exhaust, eic. Therefore prompt investigation of the actuation source is required. This LCO ensures that at least one smoke detector alarm l
l circuit, covering the area above each autoclave that is not shutdown, is operable. For l
autoclaves in the X-343 building, an autoclave smoke detector alarm circuit is required to have l
at least one operable smoke detector head above each respective autoclave pair (i.e., autoclave l
I No. I and 2; 3 and 4; 5 and 6) and above autoclave No. 7, in order to be considered operable.
l Furthermore, a single smoke watch is adequate to implement Action B.1 regardless of how l
many autoclaves may be affected. Because of the physical layout of the autoclaves and the l
smoke detector heads in the X-342 and X-344 buildings, an autoclave smoke detector alarm l
circuit in either of these two buildings is required to have both smoke detector heads operable in l
order to be considered operable. Other smoke detectors (and their associated alarm circuits) l 1
located in these facilities but not physically above the autoclaves are not covered by this TSR and l
shall not be used to satisfy the LCO requirements [SAR Sections 3.2.1.1.6, 3.2.1.2.6, and l
3.2.1.3.6].
2.1-20a
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' SAR-PORTS PROPOSED July 29,1997 RAC 97X0095 (RO)
- shows drawings of a typical single-hook crane and a sling and a typical double-hook crane and a sling.
3.2.1.1.5 X-343 C.ylinder/Pi.nine Evacuation It is necessary to evacuate small quantities of UF, purge gases, or lights from the sample system, autoclaves, pigtails or piping. This evacuation is accomplished by valving the system to be evacuated into a feed header or the X-333 evacuation line and returning these waste gases to the cascade. This method eliminates any venting to atmosphere and possible environmental insult.
3.2.1.1.6 UF Leak Detection System Tne UF leak detection system in X-343 facility provides audible and visual alarms in the event that 6
a UF release occurs. Detectors are located over the autoclaves, on the Z-Header catwalk, and on the 6
ground floor between the control panels for autoclaves 4 and 5. The detectors are grouped into ten alann circuits (also referred to as " zones") with two detectors in each circuit except for two zones covering autoclave No. 7 which have only one detector per circuit. Activation of a single detector will activate an audible and visual alarm at the system control panel. The alarm is intended to notify operators that a UF 6 leak may have occurred in the building. Operators may disable individual alarm circuits using switches located on the panel.
3.2.1.2 X-342A Feed Vaporization Facility The X-342A Facility occupies the east portion of the large X-344A/342A complex and was the former i
primary location for feed sampling and cascade feed vaporization. Another important function performed
'in the X-342A Facility is the manufacture of fluorine which is described in Section 3.4.7.
The X-342.A Facility is equipped with two seven-foot diameter Feed and Sample Autoclaves identical in design and operation to the three Feed and Sample Autoclaves in X-343.
Ten ton cylinders of UF for customer orders are sometimes sampled in the X-342A autoclaves. Then 6
the liquid-filled cylinders are removed from the autoclaves and transferred to an adjacent " cool down" area.
When the cylinders have cooled for the required amount of time defined in Section 3.2.7 to solidify the UF, they are moved from the building.
. _ Directly beneath the X-342A autoclaves is a sump which receives autoclave condensate. The sump has two pumps which discharge through an oil interceptor to a storm drain. Since the geometry of both the sump and the interceptor are nuclearly unfavorable, they contain borosilicate-glass Rashig rings as a nuclear criticality safety control.
If contamination of the sump results from a UF release, the operator can shut off the pumps and close 6
valves in order to prevent contamination of the drains.
3.2.1.2.1 Autoclaves See 3.2.1.1.1. The operation and safety systems are identical to X-343 Feed and Sampling Autoclaves.
3.2-15
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SAR-PORTS PROPOSED July 29,1997 RAC 97X0095 (RO) 3.2.1.2.2 Scales See 3.2.1.1.2.
3.2.1.2.3 UF, System Connectors and Associated Pining See 3.2.1.1.3 3.2.1.2.4 Cranes and Rigging See 3.2.1.1.4 3.2.1.2.5 X-342A Evacuation System The X-342A Facility evacuates residual UF., purge gases and lights to the cascade through feed headers.
3.2.1.2.6 UF. Leak Detection System The UF leak detection system in X-342A facility provides audible and visual alarms in the event that a UF. release occurs. Detectors are located over the autoclaves, over the llF storage room, and inside the UF storage room. The detectors are grouped into three alann circuits (also referred to as " zones") with two detectors in each circuit. Activation of a single detector will activate an audible and visual alarm at the system control panel. The detectors over the autoclaves and their associated alarm circuits are intended to notify operators that a UF. leak may have occurred in the building. Operators may disable individual alarm circuits using switches located on the panel.
3.2.1.3 X-344A Toll Enriclunent Services Facility The X-344A Toll Enrichment Services Facility is the processing and shipping / receiving point for low assay (5 % enrichment or less) toll product UF.. Typically, toll product is withdrawn from the enrichment cascade into 10-ton government-owned cylinders. Before the material can be shipped, it must be sampled and transfermd into the smaller (21/2-ton) cylinders which are usually owned by the customers and are approved for transport over highways and railways. Special shipping packages are used to protect the full product cylinders in shipment.
The X-344A building has approximately 40,000 square feet of ground floor area,18,700 square feet of second floor, and 4,300 square feet of basement floor area. The majority of the ground floor is consumed by the two high-bay areas which are served by overhead cranes and have large roh-up doors to allow entry of semi-tractor / trailer rigs, straddle carriers, forklifts, and railcars. Cool down positions are accessed by crane through the west side of the building.
The sampling and transfer operations are carried out in X-344A using any of the four autoclaves present in the north high-bay. Shipping and receiving activities can be carried out in either the north or south bay using any of the overhead bridge cranes. Cylinder unloading can occur outside the building in the X-745-B cylinder storage lot during good weather.
3.2-16
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' SAR-PORTS PROIOSED July 29,1997 J
RAC 97X0095 (RO) 3.2.1.3.1 Autoclaves The four autoclaves located in X-344A are 96-inch, containment-type units with cylinder rolling and I
tilting devices to facilitate sampling and transfer of UF contained in 12-inch,30-inch or 48-inch cylinders.
The autoclaves are rated at 150 psig. Figure 3.2-8 shows a diagram of a transfer autoclave servicing the 30-inch and 48-inch cylinders.
3.2.1.3.1.1 Autoclave Oneration With 10-Ton Cylinders A typical transfer operation consists of placing a 10-ton enriched product cylinder into an autoclave with the valve in the 12 o' clock position. The cylinder is lowered into place with the overhead crane j
positioning the cylinder on rollers. Once the cylinder is in position, an air-operated backup valve is attached to the cylinder valve and a copper pigtail is used to connect the backup valve to the UF drain line which leads to the sample / transfer manifold outside the autoclave. The conductivity cells are tested. After the connections are leak-tested, the cylinder valve is opened, the cylinder cold pressure or vacuum is measured, the autoclave is closed, the steam is turned on, and the cylinder is heated for 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. At that
},oint, the steam is turned off and evacuated from the autoclave. The UF. vapor which was introduced into the UF. pressure monitoring circuit is evacuated to the cascade and the pigtail is loosened to allow rotation of the cylinder so the valve is at the 6 o' clock position. The "back" end of the cylinder is tilted upward slightly to allow for the valve to be positioned as low in the liquid UF. level as possible. Tilting the cylinder allows for a liquid drain leaving only about 800-1000 lbs of UF. in the 10-ton cylinder. Due to space limitations, some transfer requests result in leaving about 1200-1500 pound " heels" in the 10-ton
" parent" cylinder. After the cylinder has been rolled and tilted, the pigtail is tightened, leak rated, and the autoclave re-closed. The steam is turned on again to maintain the desired temperature of 220"F until the transfer is complete. The transfer will typically consist of filling four 21/2-ton " daughter" cylinders from I
each 10-ton " parent" cylinder. Final sampling for customer acceptance is performed simultaneously with the transfer by withdrawing two approximately 1500-gram liquid samples and, in some cases, an additional smaller (usually 200 grams) sample. The sampling is effected by momentarily diverting the flowing UF.
from the transfer line into a sampling manifold which is calibrated to contain either 200 grams or 1500 grams depending on the size of the " sample loop" which was isolated by valves. The flow to the 21/2-ton cylinder is resumed and the isolated quantity of UF. is then allowed to drain into an appropriate sample cylinder which is cooled with liquid nitrogen to assure total condensation of the sample quantity. The sample -'mifold and the UF drain line are enclosed in electrically heated housings, whereas the pigtails conne tin, the 21/2-ton and sample cylinders are wrapped with electrical heaters and insulated to prevent the UF. from " freezing out" in the lines. The 21/2-ton cylinder rests on a scale while being filled to the 0.5 % weight tolerance (125.0 lbs.) written into a typical contract for enriching services.
Transfer operations are also conducted using 21/2-ton and 14 ton cylinders as parent cylinders. A transfer from one of these types of cylinders is similar to the operation described above with the exception that 21/2-ton parent cylinders are completely disconnected from the autoclave manifold during roll and tilt.
One of the samples is sent to the X-710 Laboratory for chemical and isotopic analysis. The duplicate sample is retained for a time as a " referee" in case the need would arise to reanalyze the material.
Custonner P-10 tube samples are extracted from the X-710 Lab samples and sent, if requested by the 3.2-17
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' SAR-PORTS PROPOSED July 29,1997 RAC 97X0095 (RO) j i
customer, to an independent analytical laboratory to verify the data supplied by the Portsmouth GDP laboratory. Discrepancies rarely occur between the Portsmouth GDP and audit firm analytical results; however, the " referee" sample may be used to resolve any such discrepancies. Most of the customers secure the services of an auditing firm which not only monitors the quality of the product but also monitors the quantity by observing the weighing operations performed by Feed and Transfer personnel.
The autoclaves are also typically used for sampling of 21/2-ton,10-ton or 14-ton cylinders without 1
transferring the contents. Sampling is performed in a similar manner as described above except a small quantity of UF. is allowed to flow through the sample manifold to " flush" the system and is evacuated to the cascade. Flushing removes any traces of UF. deposited in the manifold during the prior operation.
After the manifold has been flushed, the sample is taken.The autoclaves are also used for sample dumping.
Sample dumping consists of installing 5, 8, or 12-inch cylinders or a rack of sample bombs in the autoclave. The contents are then heated, liquified and transferred to a designated dump cylinder. In the case of sample bombs it is also permissible to i
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i 3.2-17a
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- SAR-PORTS April 15,1997 Rev.8 1
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Blank Page j
3.2-17b
c'.
SAR-PORTS PROPOSED July 29,1997
, RAC 97X0095 (RO) install the sample bombs on the dump rack in the upright position vice inverted as when dumping to a dump cylinder. Upright installation allows the sample bombs to be vaporized and evacuated directly back to the cascade. The Cylinder Low Pressure Cut-Off System is not a Limiting Condition for Operation in this case because once line clarity is verified, evacuation is begun immediately, which prevents cylinder pressure from ever reaching 20 psia during the heating cycle. The need for the cylinder low pressure cut-off is eliminated by the presence of a continuous vacuum which prevents any pressure build-up as well as continuous operator monitoring during the evacuation process.
3.2.1.3.1.2 X-344A Autoclave Safety Systems The safety systems for autoclaves at X-344A are functionally the same as described for autoclaves in the X-343 Feed Vaporization Facility (see 3.2.1.1.1). The autoclaves are constructed according to Section Vill of the ASME Boiler and Pressure Vessel Code.
3.2.1.3.2 Scales See 3.2.1.1.2.
3.2.1.3.3 UF System Connectors and Associated Eauipment See 3.2.1.1.3.
3.2.1.3.4 Cranes and Rigging See 3.2.1.1.4.
3.2.1.3.5 X-344A Evacuation System UF.-containing gases from pigtail purging, cylinder evacuation and cylinder sampling are evacuated to the cascade via a tie-in to the X-342 PG tie lines.
3.2.1.3.6 UF, Leaknge Detectors The UF leak detection system in X-344A facility provides audible and visual alarms in the event that a UF release occurs. Detectors are located in the north high bay over the autoclaves. The detectors are grouped into two alarm circuits (also referred to as " zones") with two detectors in each circuit. Activation of a single detector will activate an audible and visual alarm at the system control panel. The alarm is intended to notify operators that a UF. leak may have occurred in the building. Operators may disable individual alarm circuits using switches located on the panel.
The Gas Evacuation Relay (GER) system is controlled by a network of manual alarm pushbuttons and relay control wiring located throughout the entire X-344 complex to initiate autoclave containment (all four) and shut down of building ventilation systems.
3.2.1.4 Side Feed Facilities Facilities are provided to allow introduction of various assays of UF. to the equivalent assay point in the isotopic cascade.
The side feeding of UF. requires that the cylinder temperature be elevated only slightly above 3.2-18
GDP97-0128 Page 1 of 4 United States Enrichment Corporation (USEC)
Proposed Certificate Amendment Request TSR Section 2.1.3.11-Autoclave Smoke Detection System Significance Determination The United States Enrichment Corporation (USEC) has reviewed the proposed changes associated with this certificate amendment request and provides the following Significance Determination for consideration.
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- 1. No Significant Decrease in the Effectiveness of the Plant's Safety. Safeguards or Security Programs The change to the Limiting Condition for Operation for the autoclave smoke detector system is not addressed in plant safety, safeguards or security programs contained in Volume 3 of the Application for United States Nuclear Regulatory Commission Certification for the Portsmouth Gaseous Diffusion Plant. Therefore, the effectiveness of these programs is unaffected by these l
changes.
- 2. No Significant Change to Anv Conditions to the Certificate of Comnliance
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None of the Conditions to the Certificate of Compliance for Operation of Gaseous Diffusion Plants (GDP-2) specifically address Technical Safety Requirements - Limiting Conditions for Operation or their related Basis. Thus, the proposed change has no impact on any of the Conditions to the Certificate of Comphance.
- 3. No Significant Change to Any Condition of the Annroved Comnliance Plan The required action to revise TSR 2.1.3.11, autoclave smoke detector system, is not addressed by the Compliance Plan nor to any conditions of the Compliance Plan.
- 4. No Significant Increase in the Probability of Occurrence or Conseauences of Previously Evaluated Accidents l
SAR Section 4.2.3 discusses UF releases involving feed, sampling, and transfer operations. For 6
l autoclave facilities, the accident scenarios where there is, generally, the greatest likelihood of a significant release rely on the presence and actions by operators conducting the evolution to l
mitigate any release (i.e., the operators are present near the autoclaves during these evolutions 3
and are able to see any leak). There is no mention of the actuation of smoke heads in these facilities to alert operators. Nevertheless, the TSRs provide an LCO which currently requires 50% of the smoke heads to be operable, and specific actions if the level of operable heads drops below given values. The given values, in the case of the X-343 facility, represent less than 50%
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Proposed Certificate Amendment Request i
TSR Section 2.1.2.11-Autoclave Smoke Detection System Significance Determination (i.e., only 4 out of 14). Furthermore, the existing TSR does not specify which smoke heads are required to be operable for which autoclaves. These factors have caused confusion in the implementation of this TSR. The proposed change clarifies these requirements by specifying which smoke heads are required for which autoclaves. The proposed TSR requires that at least one of the two smoke head circuits for each autoclave in X-343 be operable and each operable circuit have at least one operable smoke head.
This change is consistent with requirements for smoke detectors in the existing TSR LCO Condition statement. For the autoclave areas in X-342 and X-344, the new TSR requires that j
at least one smoke detector alarm circuit shall be operable during autoclave operations and each i
circuit must have at least two operable smoke heads. As part of this change, the TSR Basis statement was changed to add text describing the intent of the LCO; to define the number of operable smoke heads required; and to clarify that only one individual is required to implement 4
action statement B.1 regardless of how many X-343 autoclaves are in the action statement.-
1 These changes are consistent with the intent of the original LCO which was to have 50% of installed detector heads operable (for X-342 and X-344) and at least 4 heads operable in X-343, and consequently do not impact the probability of occurrence of accidents evaluated in the SAR.
The revised TSR will ensure that adequate detection and alarm systems are in place during autoclave operations. Consequently, these changes do not affect the probability of occurrence or consequences of previously evaluated accidents.
- 5. No New or Different Type of Accident I
As discussed in the response to question 4, this TSR change is consistent with the intent of the existing TSR LCO requirement and therefore does not present a significant change to the current safety basis. No new or different type of accident is created by this change.
- 6. No Significant Reduction in Margins of Safety The TSRs provide an LCO (2.1.3.11) which currently requires 50% of the smoke heads to be operable, and specific actions if the level of operable heads drops below given values. The given values, in the case of the X-343 facility, represent less than 50% (i.e., only 4 out of 14) and therefore is inconsistent with the LCO premise. Furthermore, the existing TSR does not specify which smoke heads are required to be operable for which autoclaves. The proposed change clarifies these requirements by specifying which smoke heads are required for which autoclaves.
These changes are consistent with the intent of the original LCO. The revised TSR will ensure
.,., i-i GDP97-0128 Page 3 of 4 United States Enrichment Corporation (USEC)
Proposed Certificate Amendment Request TSR Section 2.1.3.ll-Autoclave Smoke Detection System Significance Determination that adequate detection and alarm systems are in place during autoclave operations. Because the level of coverage will be enhanced by specifying which detector heads are required for which autoclaves (specifically in X-343), the margin of safety is actually increased by this change.
Consequently, this TSR change does not reduce the margin of safety.
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- 7. No Significant Decrease in the Effectiveness of any Programs or Plans Contained in the Certificate Annlication The change to TSR 2.1.3.11 has no impact on any program or plan described in the Certification Application. Therefore, the effectiveness of these programs is unaffected by these changes.
- 8. The Proposed Changes do not Result in Undue Risk to 1) Public Health and Safety. 2) Common Defense and Security. and 3) the Environment.
The change to TSR 2.1.3.11, to revise the operability requirements fcr autoclave smoke detector systems does not increase the probability or consequence of any previously analyzed accident.
This change clarifies existing language in the TSR by specifying which detectors can be considered when determining operability requirements for autoclave smoke detectors. As such, this change does not represent an undue risk to public health and safety, nor affect the environment or the common defense and security.
- 9. There is no Change in the Tynes or Significant Increase in the Amounts of any Effluents that may be Released OfDilig, As discussed in response to question 4, above, this change clarifies the TSR requirements for autoclave smoke detector operability by specifying which smoke heads are required for which autoclaves. The proposed X-343 TSR requires that at least one detector alarm circuit with at least one of two smoke heads for each autoclave pair and one detector alarm circuit with its one detector head for No. 7 shall be operable. For the autoclave areas in X-342 and X-344 one detector alarm circuit, with both smoke heads operable, shall be operable during autoclave operations. These changes are consistent with the intent of the original LCO which was to have 50% ofinstalled detector heads operable (for X-342 and X-344) and at least 4 heads operable in X-343. SAR Section 4.2.3 discusses UF,, releases involving feed, sampling, and transfer operations. For autoclave facilities, the accident scenarios where there is, generally, the greatest likelihood of a release rely on the presence and actions by operators conducting the evolution to mitigate any release (i.e., the operators are present near the autoclaves during these evolutions
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GDP97-0128 Page 4 of 4 United States Enrichment Colporation (USEC)
Proposed Certificate Amendment Request TSR Section 2.1.3.11-Autoclave Smoke Detection System Significance Determination and are able to see any leak). There is no mention of the actuation of smoke heads in these facilities to alert operators. Nevertheless, the revised TSR will ensure that adequate detection and alarm systems are in place in the event of a significant UF release. Consequently, these 6
changes do not result in a change to the types or significant increase in the amounts of any effluents that could be released offsite.
- 10. There is no Sienificant Increase in Individual or Cumulative Occunational Radiation Exnosure.
i As discussed in response to question 4, the revision of TSR 2.1.3.11 will not increase Gie probability of occurrence or consequences of any postulated accident currently identified in the SAR. Therefore, there is no significant increase in individual or cumulative occupational J
radiation exposure.
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- 11. There is no Significant Construction Imnact.
This change was not initiated as a result of a plant modification, therefore it will have no significant construction impact.
- 12. There is no Significant Increase in the Potential for Radiological or Chemical Consequences from Previously Analyzed Accidents.
As discussed in response to questions 4 and 9, above, the revision of TSR 2.1.3.11 will not increase the probability of occurrence or consequenecs of any postulated accident currently identified in the SAR, nor will it result in an increase in the effluent releases. Therefore, there is no significant increase in the potential for radiological or chemical consequences from previously analyzed accidents.