ML20237E972

Safety Evaluation Supporting Amends 216 & 216 to Licenses DPR-32 & DPR-37,respectively

ML20237E972
Person / Time
Site:	Surry
Issue date:	08/26/1998
From:	NRC (Affiliation Not Assigned)
To:
Shared Package
ML20237E969	List: ML20237E966 ML20237E972
References
NUDOCS 9809010349
Download: ML20237E972 (5)

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UNITED STATES n

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NUCLEAR REGULATORY COMMISSION t

WASHINGTON, D.C. 20066-0001

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SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION l

RELATED TO AMENDMENT NO. 716 TO FACILITY OPERATING LICENSE NO. DPR-32 l

AND AMENDMENT NO. 216 TO FACILITY OPERATING LICENSE NO. DPR-37 VIRGINIA ELECTRIC AND POWER COMPANY SURRY POWER STATION. UNIT NOS.1 AND 2 DOCKET NOS. 50-280 AND 50-231 l

1.0 INTRODUCTION

l By application dated June 19,1998, as supplemented on July 14,1998, the Virginia Electric and Power Company (the licensee) submitted a request to change the Technical Specification (TS) requirements and to add a license condition for the Surry Power Station, Unit Nos.1 and 1

2. The requested changes would allow the use of a temporary 30" seismic, non-missile l

protected jumper for providing service water (SW) to the component cooling heat exchangers 1

(CCHXs) while repairs are being made to the existing CCHX service water supply piping. The I

temporary jumper would be used for up to 35 days during each of the next two Unit 1 refueling i

outages, which are currently scheduled to be performed in the years 1998 and 2000. The licensee's application also requested approval to make minor administrative changes to TS Table 3.7-2, and to correct a reference in the Bases Section of TS 3.14.

2.0 BACKGROUNQ The licensee began a service water restoration project in the fall of 1990, which includes inspection, repair, and refurbishment of the SW system piping. The next piping section scheduled for restoration is the service water supply piping to the CCHXs. This single l

concrete-encased line provides service water cooling for the four CCHXs (two for each of the I

Surry units) during normal operating and shutdown conditions. Unit 1 will be shut down in a l

refueling outage and Unit 2 will be operating at full power while this service water line is

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removed from service and an alternate supply of service water will be required to satisfy CCHX l

TS operability requirements. With one unit operating and one unit shut down, two CCHXs are l

required to be operable. The licensee plans to install an alternate service water supply line i

(otherwise known as a temporary service water jumper) to provide water for the CCHXs during j

this phase of the service water restoration project.

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The existing service water supply piping for the CCHXs takes water from the B and/or D l

circulating water (CW) inlet bays via the 96" CW supply piping, and supplies water to the CCHXs through separate branch lines and component isolation valves. A diagram of the piping arrangement is provided in the licensee's June 19,1998, submittal as Figure 1. Service water can be isolated from either the B or D CW inlet bays by a motor-operated valve (MOV) located l

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2 in each of these flow paths. These MOVs receive an isolation signal in the event of low inlet I

bay level to preseive the capability of the ultimate heat sink. The temporary jumper will take I

water from the C inlet bay via the 96" CW supply piping and a temporary manual isolation valve, and deliver it to the A and B CCHXs through a temporary manual isolation valve for each of the two heat exchangers. The jumper will be sized to provide sufficient flow to cool the Unit 1 l

ahutdown heat loads and the Unit 2 operating heat loads simultaneously. The licensee will i

install the jumper as a safety-related and seismic system, but it will not be missile-protected over its entire length. The licensee concluded that the small increase in the probability of equipment malfunction due to missile strike or heavy load drop constitutes an unreviewed safety question, and that installation and use of the jumper would require prior NRC rsview and approval. The licensee also determined that changes to the Surry TS were required to facilitate use of the temporary SWjumper and completion of this phase of the SW restoration project.

In order to support use of the temporary SW Jumper, the licensee defined project constraints

- and compensatory measures that would be implemented, proposed a license condition that acknowledges the project constraints and compensatory measures being implemented; and requested changes to TS Table 3.7-2, item 5, TS 3.14.A.2.b, and to the Basis Section of TS 3.14. The licensee also requested administrative changes to TS Table 3.7-2, item 3, and to the Basis Section of TS 3.14 that are unrelated to use of the SWjumper.

3.0 EVALUATION The licensee's submittal and supplemental information discuss the differences in design and operation that exist between the proposed temporary SWjumper and the actual SW supply line for the CCHXs, and describe contingencies that will be taken to compensate for these differences. The licensee has requested specific TS changes to facilitate use of the temporary jumper and a license condition is proposed to recognize the specific compensatory measures and contingencies that will be taken during the two 35-day periods when the normal CCHX serv'. - water supply piping will be removed from service fc,r restoration.

Based on the information submitted by the licensee, the temporary jumper will satisfy the same design requirements as the existing CCHX SW supply line, with only a few exceptions. The staff's review focused on the differences that will exist in design and operation between the

- temporary jumper and the CCHX SW supply line, and on measures being taken by the licensee to compensate for these differences. In reviewing the information provided by the licensee, the

- following aspects of jumper design and operation were identified for staff consideration:

The jumper can take water from only one inlet bay (C), whereas the existing SW supply line can take water from two inlet bays (B and D).

Two of the four inlet bays will be dewatered during this phase of the SW restoration work in order to allow access to the existing CCHX SW supply line.

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l A manual valve will be used for isolating the jumper and automatic isolation capability will not exist, whereas the existing SW supply line is automatically l

isota'ed by motor-operated valves when 3 out of 4 inlet bay levels are low in order to preserve the ultimate heat sink.

l The jumper will not be missile protected over its entire length, and will be more l

vulnerable to missiles, heavy !oad mishaps, and vehicular impact.

l The jumper will be more limiting in its flow capability than the existing SW supply l

line and will only provide SW to the A and B CCHXs, rendering the other two CCHXs inoperable.

Interim use of the temporary jumper could be a confusion factor for plant operators and station personnel.

l The licensee's submittal and supplemental information recognize these aspects of jumper design and operation, and establish specific project constraints and compensatory measures in order to support interim use of the temporary jumper.

included among the compensatory measures that will be established is a Contingency l

Action Plan (CAP) that will be in effect whenever the jumper is in service. The CAP l

establishes criteria for restoring the normal CCHX SW supply line to service in the event l

that continued use of the temporary jumper may be jeopardized due to weather i

conditions (for example) or if conditions associated with the operating unit (Unit 2) should warrant such action. The project constraints and compensatory measures provide assurance that:

the temporary jumper will be able to perform its intended function during each of l

- the two 35-day periods when the normal CCHX SW line is removed from service; l

l the normal CCHX SW supply can be restored within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br />; and i

the Unit 1 reactor coolant will remain subcooled for at least 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> (during most l

of the SW restoration work) in the event that flow through the temporary jumper l'

is interrupted.

The licensee has determined that the most limiting condition will occur during a 3%-day time period towards the end of the Unit i refueling operation, when reactor vessel integrity is being restored. Should loss of SW flow through the temporary jumper occur during this period, boiling of the reactor coolant could occur in about 36 minutes, and fuel clad damage could occur in about 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. However, alternate cooling to mitigate this event will be assured by Operations Surveillance Procedure 1-OSP-ZZ-004, " Unit i Safety Systems Status List for Cold Shutdown / Refueling Conditions," and Abnormal Procedure 1-AP-27.00, " Loss of Decay Heat Removal Capability." Based on simulation L

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of this event, the licensee has determined that attemate cooling can be established in about 15 minutes. Assuming that 10 minutes will elapse before operator action is taken, attemate cooling should be established before the reactor coolant begins to boil and well before the onset of fuel clad damage.

By establishing appropriate project constraints and compensatory measures, the licensee has adequately addressed the differences that exist in design and operation of the temporary SWjumper as compared to the normal CCHX SW supply line. The staff finds that interim use of the temporary SWjumper, as discussed in the TS amendment request dated June 19,1998, as supplemented July 14,1998, is appropriate and justified, and that use of the temporary jumper is acceptable provided that the project constraints and compensatory measures are implemented as described. Further, the staff finds that the proposed license condition provides adequate assurance that the project constraints and compensatory measures will be implemented and that the.

requested changes to TS Table 3.7-2, item 5, TS 3.14.A.2.b and to the Bases Section of TS 3.14 are necessary and acceptable for facilitating use of the temporary jumper.

However, the staff has clarified the footnote to TS 3.14.A.2.b and the change to the Bases Section of TS 3.14 in order to identify the specific Unit 1 outages (SI-R-15 and SI-l R-16) when the temporary jumper will be used in order to avoid any confusion in the L

future. Finally, the proposed administrative changes to TS Table 3.7-2, Item 3, and to the Bases Section of TS 3.14 are editorial in nature and are, therefore, acceptable.

4.0 STATE CONSULTATION

in accordance with the Commission's regulations, the Virginia State official was notified of the proposed issuance of the amendments. The State official had no comment.

5.0 ENVIRONMENTAL CONSIDERATION

These amendments change a requirement with respect to installation or use of a facility component located within the restricted area as defined in 10 CFR Part 20. The NRC staff has determined that the amendments involve no significant increase in the L

amounts, and no significant change in the types, of any effluents that may be released offsite, and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that these amendments involve no significant hazards consideration and there has been no public comment on such finding (63 FR 38206). Accordingly, these amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of these amendments.

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6.0 CONCLUSION

The Commission has concluded, based on the considerations discussed above, that:

(1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuonce of these amendments will not be inimical to the common defense and security or to the health and safety of the public.

Principal Contributors: James Tatum Coretta Y. Saadu Date:

August 26, i998