ML19324B323
| ML19324B323 | |
| Person / Time | |
|---|---|
| Site: | Oyster Creek |
| Issue date: | 10/18/1989 |
| From: | GENERAL PUBLIC UTILITIES CORP. |
| To: | |
| Shared Package | |
| ML19324B319 | List: |
| References | |
| NUDOCS 8911060047 | |
| Download: ML19324B323 (8) | |
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{f h, [ , j' s OYSTER CREEK NUCLEAR GENERATING STATION e a w .
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fa' PROVISIONAL OPERATING LICENSE NO. DPR-16
, DOCKET NO. 50-219 l
. TECHNICAL SPECIFICATION CHANGE REQUEST NO. 175
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p' [ Applicant hereby requests the Commission to change Appendix A to the above j captioned license as indicated below, and pursuant to 10CFR50.91, an analysis concerning the determination of no significant hazards consideration is also '
presented:
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- 1. Accendix A Chances 5 Technical Specifications 3.17 and 4.17 ,
2'. , Extent of Chance
- a. Propose that two Control Room HVAC Systems shall be operable during all modes of plant operation.
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- b. Propose new limiting conditions for operation for the Control Room ,.
HVAC Systems.
- c. Propose the deletion of the surveillance to determine the makeup air plus infiltration air (< 2000 cfm) to the Control Room envelope for each Control Room HVAC system..
- 3. Chances Recuested ,
The proposed changes to Appendix A, Technical Specifications, are shown l on attached pages 3.17-1 and 4.17-1.
4.- ImD19 mentation ,
1 It is requested that the amendment authorizing this change become effective 60 days after issuance. I, l 5.- Discussion ,
l, a) Background l
Amendment 105 deferred the final system upgrades for Control Room Habitability to the 12R outage. These system upgrades included the followings (1) perform a single failure analysis of the control ;
room ventilation system and provide remedial measures, (2) assess existing diesel generator capability to provide backup power to the control room ventilation system and (3) meet the beta skin dose h limits with the final control room ventilation system design witnout protective clothing and goggles.
As the result of the 12R system upgrades, the Control Room has two R independent HVAC systems. Each system has four manual operating modes designated as normal, purge, partial, and full recirculation.
The existing HVAC system is System A, and the 12R modification which includes a separate fan, dampers, and a refrigeration unit is System B.
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e b:,f-hp t 3.17 Control Room Heatino. Ventilatina, and Air-Conditionino System
, (poliesbilitva- Applies to the operability of the, control room heating, '
. ventilating, and air conditior.ing (HVAC) systems.
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p_" . .iijtetive To assure the capability of each control room HVAC system to- ;
2 minimize the amount of radioactivity from entering the '
control room in the event of an accident.
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Eggqification: A. Two control room HVAC systems shall'be operable during all modes of plant operation. >
r B. With one control room HVAC system determined inoperable: ;
(1) Demonstrate once per 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> the partial {
recirculation mode of operation for the operable i system, ' or place the operable system 'in the t '..tial-recirculation modes and [
i (2) Restore the inoperable system within 7 days, or prepare and submit a special report to the ;
commission in lieu of any other report required by
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' section 6.9, within the next 14 days, outlining the action taken, the cause of the inoperability and the plans / schedule for restoring the HVAC system to l operable status.
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C. With both control room HVAC systems detsrmined inoperable, i (1) During Power Operations place the reactor in the !
cold shutdown condition within 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> t i
(2) During Refueling:
(a) Cease irradiated fuel handling operations; e.nd i I
(b) Cease all vark on the reactor or its connected systems in the reactor building which could [
result in inadvertent releases of radioactive '
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materials. '}
Basis: The operability of each control room HVAC system ensures that the !
control room will remain habitable for operations personnel during a !
postulated design basis accident. The control room envelope includes the control room panel area, the shift supervisor's office, l toilet room, kitchen, and lower cable spreading room. Since systems .;
A and B do not have HEPA filters or charcoal adsorbers, the supply j ten and dampers for each system minimize the beta and gamma doses to ;
a the operators by providing positive pressurization and limiting the l makeup and infiltration air into the control room envelope. For the 4
. supply of 100% outside air to the control room envelope, the doses e
- f. increase to 29.1 rem beta and 3.14 rem gamma for the assumed 30 e dayc; how3ver, these values are within the allowable limits.
OYSTER CREEK 3.17-1 Amendment No.: 115
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4: 6' i 4.17 Control Room Heatina. Ventilatino. and hir-Conditionino Systeta
- Y l# hoolicability
- Applies to surveillance requirements for the control room heating, ventilating, and air conditioning (KVAC) systems.
i obiective To verify the capability of each control room HVAC aystem to ,
minimise the amount of radioactivity from entering the control room in the event of an accident. ,
i specification Surveillance of each control room HVAC system shall be as follows: ,
l A. At least once montbly: by initiating, from the control room, the partial recircu$stion mode of operation, and i by verifying that the system components are aligned such ,
that the system is operating in this mode. l t
B. At least once every refueling outages by verifying that in the partial recirculation mode of operation, the t control room and lower cable spreading room are maintained at a positive pressure of 21/8 in. Wo .
relative to the outside atmosphere.
r pasist Periodic surveillance of each control room HVAC system is required i to ensure the operability of the system. The operability of the system in conjunction with control room design provisions is based upon limiting the radiation exposure to personnel occupying the control room to less than a 30-day integrated gamma dose of 5 rem, and a 30-day integrated beta dose of 30 rem. :
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i OYSTER CREEK 4.17-1 Amendment No.: 155
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F .. l l < 5. gg,t erminat ion Based upon ;.no hereinbefore discussion, we have evaluated that this l )
[ change request involves no significant hasards consideration. In i summary, we have determined that the proposed amendment would nott l
- 1. Involve a significant increase in the probability or consequences of l an accident previously evaluated; i
- The Control Room HVAC system was novat determined to be an initiator of an accident previously analyzed, nor was the {
system postulated to mitigate the consequencer. cf any design basis accidents. The proposed changes to the TS will not revise the accident analysis, so the probability and consequences of UPSAM accidents remain the same. ;
- 2. Create the probability of a new or different kind of accident from any accident previously evaluated; 1
- Since no changes are proposed to the plant operating j parameters, safety limits, or safety system settings, this change does not create the possibility of a new or different j type of accident. This change proposos a new LCo and a change ,
to the inleakage reqcirements for Systems A and B. ;
- 3. Involve a significant reduction in a margin of safety; l The licensing basis for the Control Room HVAC system is to minimize the operator's exposure to either a release of radioactive gases following a LOCA or the re. tease of toxic gases from onsite release ,
of liquid chlorine. The proposed changes to TS sections 3.17 and ;
4.17 (1) eliminate the makeup air plus infiltration requirement (s 2000 cfm); (2) adds more ramtrictive limiting conditions for ,
operation; (3) and identifies that System B must meet the same l surveillance requirements that are currently required for System A. !
Since the 2000 cfm limitation was determined not necessary to meet the allowable Beta and gamma doses to the operators, the elimination '
of the requirement does not alter the margin of safety inherent in ;
F the allowable values. Since changes #2 and #3 impose more !
restrictive or retain equivalent LCo's and surveillances, there is no change to the margin of safety. ;
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- s b) Safety Function i
The safety function of the control Room EVAC system has two !
principal objectives. First, is to assure that plant operators are [
adequately protected against the effects of an accidental release of l toxic or radioactive gases. Second is to provide a habitable ;
l- environment so that the plant can be safely operated or shut down !
under design basis accident conditiens.
c) Effect of the Proposed TS Change on the Safety Function i This activity proposes new limiting conditions for operation and :
clarifies surveillance requirements for Systems A and B. Presently, ;
TS Sections 3.17 and 4.17 recognize only a single system, and the !
installetion of a separate system provides remedial measures to -[
address a potential single failure of an active component in either system. As designed, Systems A and B are not safety related and i share common passive equipment. ;
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- 1. Toxie cas Analysis chlorine transport analyses for a one ton liquid chlorina tank
'4 cylinder were submitted with letters dated August 16, 1985 and September 29, 1986. With the removal of the one ton cylinders i during early 1987, the probability of an onsite toxic gas {
release affecting control roo;n habitability was minimised for 0.C, Based on this fact, the NRc Staff through an SE (Ltr. i dated 11/14/86) allowed O.C. to exclude TS requirements for chlorine detection.
A review of the chlorine transport analysis was performed for an instantaneous and a continuous release (3/8 inch line break) for a 150 lb cylinder which is stored at a new location approximately 380 feet from the control room intake. The analysis took no credit for mixing of the chlorine plume due to the effects of a building wake, and the analysis also assumed ;
the wind direction is such that the centerline of the chlorine plume at ground level blows directly towards the control room air intake (approximately 41 feet above plant grade).
f Fortheinstantaneousandcontinuousreleasosundeg)various meteorological conditions, a toxic limit (0.045g/m was only '
echieved in the control room envelope when the control room received tir from outeide sources at rates greater than 13,000 l
cfm (inatantaneous chlorine release) and 1750 cfm (continuous i chlorine release until cylinder is depleted). These flow rates :
I were also assumed constant for the duration of the accidental chlorine releases. The minimum times to achieve a toxic limit I were calculated as 320 reconds (instantaneous chlorine release) and 372 seconds (continuous chlorine release). Allowing 5 seconde for the detector loop response time, the minimum required operator response times to switch to f ull recirculation ,
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were 315 seconds (instantaneous chlorine release) and 367
, seconds (continuous chlorine release).
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The radiological analysis assumed the containment pressure would decrease to O psig in 10 days post LOCA. This assumption i equated to 1000 standard cubic feet (SCF) of MSIV bypass leahage
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3 for the dose assessment.
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j f The MSIV leakage was reassessed considering MSIV leakage as a
[ function of accumulator and containment pressures. GPUN 1 l' calculated a MSIV bypaes leakege of 243 SCF for the first day j post LOCA. This calculation assumed that the Prywell pressure l
! decays to 1 poig in about 2 1/2 hours then remains constant I lL until 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> after the LOCA. Since the Updated FSAR (FigLre ,
n 6.2-3) shows O peig within 6 1/2 hours, this pressure profile ,
l was considered conservative for the assessment.
The MSIV bypass leakage calculated by the radiological analysis !
(1000 SCF) exceeds the bypass leakage calculated by the MSIV l 1eakage assessmsnt (243 SCF). Since the MSIV bypass leakage is I i the major contributor to the control room dose, the assumptions ,
used for the radiological analysis are conservative when compared to the expected MSIV behavior (12R tests) and l containment pressure response (FSAR Fig. 6.2-3) during a LOCA. -
Further, the assumptions used for the main steam line volume (exclusion of main steam line header and piping volume up tn the ,
turbine stop valve) and for calculating the beta skin dose ;
(inclusion of iodine daughter products) are conservative.
Therefore, the radiological analysis of record is still bounding.
Based on these facts, the current requirements on the maximum makeup air plus infiltration rate ($ 2000 cfm) during the partial recirculation mode of operation is no longer warranted. l Therefore, this activity proposes a revision to T.S. 4.17B to retain only a surveillance for the positive pressurization (2 1/8 in Wo.) during the partial recirculation mode of operation. ;
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Amendment 115 also requested additional TS requirements for i maximum temperature control within the control room envelope or provide justification for not needing this TS requirement. ;
oyster Creek had also identified the need for temperature ;
control during normal plant operations (no radiological or toxic '
gas release) and had revised station procedurns to provide precautions and remedial actions for a loss of normal ventilation. Since the existing station procedures already ;
recognise the importance of the control room temperature during ~
normal plant operations and provide a measure of assurance on ;
the manner in which the plant is being operated, an additional ,
TS requirement is not warranted. i t
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6-As previously stated, the supply fan and dampers for each system are the co.mponants which establish and waintain the partial recirculation mode of operation. Since the supply fan runs continuously in the normal or partial recirculation modes, its inoperability would be immediately apparent to the control room
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operators. Therefore, the f ailure of the dampet s to realign to the partial recirculation mode of operation is the area of concern subsequent to a release of radioactivity within the Reactor Building. As an option to placing and maintaining partial recirculation for the operable system during a LCO, this i
activity also proposes increasing the frequency of the damper alignment surveillance from once per month to once every 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. This new LCO veuld provide a level of assurance on the capability of the operable system to perform its design function during a design basis accident.
If both systems become ineperable, the capability to minimize the radiation exposure or to maintain the control room temperature during a radiological release is diminished. Based on these facts, this activity proposes: (1) place the reactor in the cold shutdown condition; and (2) cancel work activities on the reactor vessel or its connected systems, and handling of irradiated fuel.
By Amendment 115, the NRC staff accepted the radiological analysis results of 3.07 Rem gamma and 28.2 Rem beta for an infiltration rate of 2000 cfm in the partial recirculation mode of operation. The radiological analysis assumed the partial recirculation mode of operation for a design basis LOCA and excluded the effects of a Loop concurrent with a LOCA pending the implementation of the Long Term Design Objectives. Since the System (A or B) would be tripped with a LOOP concurrent with a LOCA, a review of the radiological analysis was performed to account for partial restoration (supply fan only) of a system with 100% outside air to limit the control room maximum temperature (104'F) when ambient temperatures (82'F) permit this mode of operation. The revised calculation assumed continuous operation (supply tan only) for 30 days. Since CPUN estimatas that offsite power and full System (A or B) capability will be reste ad within two hours, this, assumption is conservative. For the apply of 100% outside air to the control room envelope, the calculated doses increased to 29.1 Rem beta and 3.1 Rem gamma for the assumed 30 days; however, these values were still within the allowable limits of 30 Rem beta and 5 Rom gamma.
During 12R, the main steam isolation valvo (MSIV) leakage rate was determined by tests to vary from the leakage rate assumption used in the radiological analysis. The leakage rate is a function of the MSIV air accumulator pressure and the post LOCA containment prescure. The radiological ana'.ysis assumed the Technical Specification limit for MSIV leakige post LOCA with leakage decreasing as a function of the por.t LOCA containment pressure. MSIV air accumulator pressures were not accounted for in that analysis. Therefore, the assumed behavior of the MSIV leakage rate differed from the actual behavior observed during the 12R testing.
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The 12R control room KVAC tests have demonstrated a makeup air
- plus infiltration rate less than 1750 cfm for the full recirculation node of operation. The kitchen / toilet exhaust fan (FN-826-009) was off. In order to minimize operator actiono E
during an accidental release of toxic or radioactive gases, the ;
[ kitchen / toilet exhaust fan will be normally off except for limiting periods when the kitchen / toilet areas are in use. A timer on the switch limits continuous operation for a maximum of
(' five minutes, so that there administrative restrictions (11R) agreed to by CPUN and NRC on the kitchen / toilet exhaust fan are not violated. i The minimum required times for operator response are by analysis l greater than the minimum operator response time (120 seconds) ;
required by Regulatory Guide 1.78. Due to these facts and the ?
conservative assumptions noted above, we have concluded that the control room operator has sufficient time from the receipt of chlorine alarm to place the control room HVAC System (A or **
into full recirculation, and the need to don respiratory equipment is not warranteds Therefore, the presence of the 150 lb. liquid chlorine cylinder, does not invalidate Item #7 of the 11R Interim System Upgrades for Control Room Habitability.
- 2. Radioloalcal Analyses ;
Since neither system has HEPA filters or charcoal adsorbers, the partial recirculation mode of operation minimizes the l Infiltration of radioactive gases by pressurizing the control i room envelope and minimizing the flow rate of makeup air pluo infiltration air to the control room envelope. The supply fan and dampers for each system are the components which establish !
and maintain this partial recirculation mode of operation. By assuring the operability of each system in the partial recirculation mode of operation, the operators can minimize the amount of radioactivity that enters the control room envelope ;
following a design basis LOCA.
During shutdown, the potential sources for a release of ,
radioactive material are from fuel handling operations, and work [
on the reactor or its connected systems (fuel in the vessel) l with the potential of drainirag the vessel below the top of the ,
active fuel. Since OC does not have to consider the thyroid ;
dose, GPUN opted not to perform a separato radiological analyses for these conditions by assuming that a dasign basis LiCA j enveloped these conditions for the source terms considered.
This activity proposes a new LCO when one system is deterrained i
inoperable (supply fan and/or dampers) for more than 7 days.
The objective is to maintain operability of the other system until the inoperable system is restored.
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