ML19332F371
| ML19332F371 | |
| Person / Time | |
|---|---|
| Site: | Brunswick  |
| Issue date: | 12/05/1989 |
| From: | Loflin L CAROLINA POWER & LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NLS-89-316, NUDOCS 8912140339 | |
| Download: ML19332F371 (5) | |
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Carolina Power & Light Company DEC 0.51989 SERIAL:
10CFR50.90 84TSB08 United States Nuclear Regulatory Commission ATTENTION: Document Control Desk' Washington, DC 20555 BRUNSWICK STEAM ELECTRIC PLANT, UNIT NOS. 1 AND 2
. DOCKET NOS. 50-325 & 50-324/ LICENSE NOS. DPR-71 & DPR-62 PRIMARY CONTAINMENT ISOLATION SYSTEM
_ RESPONSE TO REQUEST FOR ADDTIONAL INFORMATION Gentlemen:
On October 12, 1989, during the monthly status meeting with the Brunswick
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' Project Manager, CP&L was provided a number of questions pertaining to the September 20, 1989 license amendment request regarding the Primary Containment Isolation' System. contains the Company's responses to six of the seven' questions. The information required for the response to Question 3, regarding RWCU Isolation - A Flow High, will take longer to compile.
It is expected that this information can be provided by the end of December 1989 or early January.1990.
Please refer any questions regarding this submittal to Mr. M. R. Oates at (919) 546-6063.
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Yours very truly, l
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Leon rd I. Loflin Manager j
Nuclear Licensing Section L:
LIL/ MAT
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t Enclosure cc:
Mr. D. H. Brown I:
Mr. S. D. Ebneter Mr. W. H. Ruland Mr. E. G. Tourigny 8912140339 891205 PDR ADOCK 05000324 P'
PDC h00I 411 Fayetteville Street
- P. O. Box 1551
- Ralesgh. N C. 27602 1
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33 ENCLOSURE 1 BRUNSWICK STEAM ELECTRIC PLANT, UNITS 1 AND.2
- 5 NRC DOCKETS 50 325 6.50-324 OPERATING LICENSES DPR-71 & DPR 62-PRIMARY CONTAINMENT ISOLATION SYSTEM n.
i RESPONSE T0' REQUEST-FOR ADDITIONAL-INFORMATION-
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-Ouestion 1 l
Proposed Change Number 3 --Subpart A:
Please provide a better description of each' change and the basis for it.
Action statements are being changed for some valve: groups-(1.a 1 and 5.a).-
A new valve group-is being identified and action statements are being changed (2.a 2.b,-and 2.c).
Response
D' Currently. Valve Groups. actuated by an isolation signal are specified under i
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the. trip. function regardless of whether the actuated Valve Groups are.
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' associated with that isolation function.
As an example, Valve Groups-2, 6,-
and 8 are 11sted under both trip functions 1.a.1,-Primary-Containment 1
Isolation, and 5.a, Shutdown Cooling. System Isolation, even though' Valve JGroups'2;and 6 are associated with primary containment isolation and Valve Group-8 with shutdown cooling system isolation. As a result,-the Technical Specifications are not consistent in specifying the correct action if the q
operability requirements are not-met.. In the above case, Item 1.a.1 requires j
- Action 20 for Valve' Groups 2, 6, and 8 whereas Item 5.a specifies-Action 27.
for these same groups, Action 20,.as specified by Item 1,a.1, is appropriate:
for Valve Groups 2 and-6 because both are associated with primary containment.
Action ~27, specified in Item 5.a. is appropriate for Valve Group 8 since it is associated with shutdown cooling system isolation. The nature of-the action i
specified by Action 27 would.not compensate for the inoperability of the Valve.
Group 2 and 6 instrumentation'and, as such, is inappropriate for that condition, j
1 Similar changes are necessary for Items 2.a, 2.b, and 2.c.
These items j
. address the operability requirements for the secondary containment-isolation
-j system, instrumentation, however, the secondary containment isolation dampers are not identified as a valve group operated by the items. This-change adds j
footnote (1) which references the secondary containment isolation dampers.
The specified Action 23 is correct for the secondary containment isolation dampers, however, it is not-for Valve Groups 2, 3, and 6 which are not reinted to secondary containment. The corrcct actions for these valve groups are j
specified by the primary containment isolation section for Valve Groups 2 and 6 and the reactor water cleanup system isolation system section for Valve Group 3.
These sections are specifically provided for these isolation i
functions and contain the appropriate actions.
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_The proposed changes'wil1~make the information provided more complete and accurate.
It does not reflect a change in the design or operation of the instrumentation ~..
4 Ouestion 2-1
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- Proposed. Change Number 4 - General:
Isolation system response times, in
_ general, are discussed in the basis for the changes.
Load sequencing times of L
- valve power sources are not discussed.
Is it correct to assume that there is l
no load sequencing for the valves covered by the Technical Specifications?'
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.Please discuss.
In addition, assumptions were given for AC powered valves.
Please describe what assumptions are used for DC_ powered valves.
Response
i The electrically operated primary containment isolation valves are powerad from either AC or DC motor control centers which are not subject.co. load sequencing. Power is.immediately available to these valves whenever a source-of;.onsite-or.offsite power is present. The accident analysis assumes a maximum response time for isolation of a containment penetration by the isolation system.
Because of the single' failure criteria, the' response time must be based ~upon the; slower of the inboard and outboard valves in order to be conservative. Where one of these isolation valves is AC powered, the system response time takes into account the time required for the emergency diesel generators-to start and supply power to the AC valve. This allowance is not.necessary for penetrations which employ only fail close DC, or air operated valves as their operation does not depend on AC power being -
available.
Ouestion'3 Proposed Change Number 4 - RWCU Isolation 6 Flow High: Please confirm that the isolation time for-RWCU under high differential flow conditions is bounded by the high energy' line break accident analysis.
Please address.the following
-times:
instrument response time and value;.AC/DC valve closure time and Evalue; diesel generator start time and value; time delay timer time and value; loading sequence delay time and value; and total RWCU isolation time and value.
Response
To be provided at a later date.
Ouestion 4 Current Item 4.b.4 in Table 3.3.2-3 specifies an "NA" for response time.
i Shouldn't this value be s 30 minutes as stated in UFSAR Table 7.3.1-3, PCIS Group 5?
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Response.
UFSAR Table 7.3.1-3 specifies the setpoints for the isolation instrumentation, j
It specifies a setpoint of s 30 minutes for the RCIC steam tunnel temperature time delay relay. This design requirement is specified as an operability E
requirement under Item 4.b.11 in Table 3.3.2-2 of the Technical Specifications. This table is where setpoint requirements are addressed by the Technical Specifications.
Technical' Specification Table 3.3.2-3 specifies the overall response for isolation instrumentation. A response time requirement is necessary for isolation signals which are depended upon to initiate the protective actions for the worst case, bounding breaks. An instrumentation response slower than these response time design limits would result in environmental conditions in excess of the environmental qualification envelope.
For these isolation signals a response time requirement is needed because its value is critical in
.l ensuring the design basis event does not exceed the bounding envelope.
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The RCIC' steam line tunnel high temperature instrumentation does not have a l
response time limit because its operation is not depended upon to mitigate the worst case high energy line break event. It is only depended on for providing protection against small RCIC line breaks which are not bounding.
Since the environmental qualification profiles for these breaks are enveloped by other
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breaks, the response-time of the instrumentation is not critical to the acceptable performance of the system. There is sufficient margin from the bounding profiles that a response time limit is not necessary to assure proper j
operation of the instrumentation isolation function.
Evidence for this is 1
provided by the 30 minute time. delay designed into the system.
Verification of the setpoint of this relay is addressed by Item 4.b.11 in Table 3.3.2-2.
The magnitude of this time delay is so great (1800 seconds) that any variation in the instrumentation response time is immaterial.
Therefore, an overall response time test for the instrumentation is not necessary.
j Ouestion 5 i
Proposed TS page 3/4 6-20 has multiple " margin bars" showing changes.
It i
appears from the text that only one change is being make (revise " Condition" to " Operational condition") and this would support only one "mergin bar."
i Please address the discrepancy.
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Response
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The word " CONDITION" currently appears in three places in Technical Specification 3.6.5.2, each of which was changed to "0PERATIONAL CONDITION."
l The three revision bars identify these changes.
Question 6 Proposed Change 5 - Isolation Valves:
Please provide a comparison of valves listed in current TS Table 3.6.3-1 with the listing of valves covered by the l
new procedure.
If valves are listed in the TS and not the procedure, justify El-3
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i the deletion.
If valves are listed in the procedure and not the TS Table, explain the discrepancy.. In addition, please confirm that the current TS.
Table ~ valves' isolation times are' contained in the new procedure and are the same numerical values.
If differences exist, please ' explain and justify.
Response
The. current Technical Specifications lists only automatic isolation valves l
with stroke time requirements. Technical Specification Interpretation 85 01 q
expands'the' applicability of Technical specification Section 3.6.3 to include.
the list of the primary containment. isolation valves contained in existing-Plant Procedure SD-12.
The new plant procedure will-specify both the valves in existing Technical Specification Table 3.6.3-1 and those in existing plant procedure SD-12.
It will also specify the same isolation times as currently l
specified by the Technical Specifications. The list of valves and requirements specified by the new procedure..therefore, will be the same as that currently specified by the Technical Specifications as expanded by the Technical Specification Interpretation,
. i Ouestion 7 Proposed Change 5 - Isolation Dampers:
Same questions as contained in Question 6 but for TS Table 3.6.5.2-1 instead of TS Table 3.6.3-1.
Response-The new procedure will contain the same list of secondary containn<ent dampers and stroke times as currently contained in the Technical Specifications so
. there will ico no change from the current requirements.
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