ML18093A662

From kanterella
Jump to navigation Jump to search
Justification for Operation of Units 1 & 2 W/Limited 4KV Loads.
ML18093A662
Person / Time
Site: Salem  PSEG icon.png
Issue date: 08/31/1986
From:
Public Service Enterprise Group
To:
Shared Package
ML18093A661 List:
References
S-C-E130-NSE-04, S-C-E130-NSE-0458-0, S-C-E130-NSE-4, S-C-E130-NSE-458, NUDOCS 8802250229
Download: ML18093A662 (6)


Text

ATTACHMENT 1 Page 1 of 3 PS~G

/

S-C-El30-NSE-0458-0 Date: 8/31/86 Public Service Electric and Gas Company P.O. Box 236 Hancocks Bridge, New Jersey 08038 Nuclear Department TITLE: JUSTH'ICATION FUR OPERATION OF UNITS 1 AND 2 WITH LIMITED 4KV LOADS

1.0 PURPOSE

This safety evaluation is being written to justify the continued safe operation of Salem Unit #1 and Unit #2 following the reactor trip/safety injection and subsequent loss of offsite power indication which occurred on Salem Unit #2 on August 26, 1986.

2.0 SCOPE

This safety evaluation is applicable to the operation of both Salem Unit #1 and Salem Unit #2.

3.0 REFERENCES

3.1 U.S. NRC letter "Adequacy of Station Electrical Distribution System Voltages at Salem Units 1 and 2" to F. W. Schneider, dated October 21, 1981.

3.2 "Adequacy of Station Electric Distribution System Voltages, Salem Nuclear Power Station Units 1 and 2".

Prepared for U.S. NRC by EG&G Idaho, Inc., June, 1981.

3.3 U.F.S.A.R., Section 8 and Section 3 3.4 Salem Nuclear Generating station Technical Specifi-cations bases.

3.~ G.o.c. 17, Electric Power Systems 3.6 Public Service Electric and Gas Company Drawings 203061 A8789 and 203062 A8789 4.U DISCUSSION:

Un August 26, 1986, Unit #2 experienced a reactor trip and safety injection tallowed shortly by a loss of offsite power to the 4KV vital A, B, & C electrical busses. Initially on the safety injection, all safeguards loads loaded simultaneously in accordance with the desiyn. Subsequent to the safety injection an indication of loss of offsite power was received. The "A" and "C" vital bus loads sequenced onto the diesels as per design. The "B" vital bus remained deenergized because the "B" diesel generator was tagged for 8802250229 860831 PDR ADOCK 05000272 p PDR L NED/~O 11.

  • FORM l REV 0 1USEPT81 95-216811001\11 ;2-8J

Page 2 of 3 Date: 8/31/86 maintenance. (Two vital 4160 volt busses are required to provide minimum safeguards equipment). Upon investigation it was determined that equipment failures did not initiate the loss of offsite power event. The investigation revealed that a transient stability analysis had not been performed on the plant since June, 1981. Plant loads have been modified on the basis of a static loading analysis only.

The changes in plant loads may be found in Attachment #1.

The June, 1981 transient stability analysis was performed by Public Service Electric and Gas (PSE&G) and supplied to the U.S. NRC in accordance with a request dated August 8, 1979. The U.S. NRC then submitted this study to their contractor EG&G, Idaho, Inc. for review. The U.S. NRC then supplied PSE&G with a Safety Evaluation Report which approved the Salem Unit No. 1 and Unit No. 2 electric distribution system (Reference 3.2).

5.0 RECOMMENDATIONS Since a transient stability analysis has not been performed since June, 1981, operation of the Salem Unit #1 and Unit #2 plants may only be continued when the plant loads are returned to within the values identified in the study and approved by the NRC. In addition, the plant loads will be supplied from the station power transformers with the auxiliary power transformer group bus infeed breakers open.

This will further remove the potential transient load added to the station power transformers when a group bus transfers from the Auxiliary power transformer. The reduced loads identified in Attachment II will result in more conservative loads than that which were identified in the June 1981 study.

6.0 CONCLUSION

S:

The continued operation of Salem Units 1 & 2 is justified on the basis ot the discussion above. Implementation of the above recommendations do not constitute an Unreviewed Safety Question since, a) It does not involve a modification, test or experiment associated with equipment important to safety, but rather the administrative operation of balance of plant equipment, b) It is based on the results of analysis for a modification of a type previously approved by the NRC (Ref.

3.2), c) It recommends the administrative control of oper-ation of non-vital equipment that are not part of the basis for any Technical Specification (See attachment).

7.0 VENDOR MANUAL IMPACT None.

NED/50 11.*FORM 1 REV 0 10SEPT81

Page 3 of 3 Date : 8 I 3 1I8 6

8.0 SIGNATURES

~J

,ew. ~."-1L tJbJ/e<o

/)_;J ch~~ 9/:31/?6 Originator Date Verifier DbtJ

-!.~ ~er Group Head

/'M--v-. ~~/;,r Group Head System Analysis Manager - Date Plant Engineering NED/50 11.* FORM 1 REV 0 1 OS E.l?T81

ATTACHMENT I - Changes in plant loads Unit 1 11 Station Power Transformer 12 Station Power Transformer Group 2000 KVA ( 2 ) Cond. Pumps 1000 KVA ( 1 ) Cond. Pump Busses 333 KVA Misc. Subs. 333 KVA Misc. Subs.

Vital 833 KVA Mi SC. Subs 833 KVA Misc. Subs Buss es 3166 KVA Total 2166 KVA Total Unit 2 21 Station Power Trans former 22 Station Power Transformer Group 6000 KVA ( 3) Cond. Pumps 1000 KVA ( 1 ) Cond. Pump Busses 1000 KVA Non Rad Waste 333 KVA Misc. Subs.

333 KVA Mi SC. Subs Vital 833 KVA Mi SC. (Subs) 833 KVA Misc. Subs Buss es 8166 KVA Total 2166 KVA Total

ATTACHMENT II Equipment to be out of service to obtain reduction of Station Power Transformer Loads Unit #1 11 Station Power Transformer 12 Station Power Transformer must reduce by 3166 KVA, any must reduce by 2166 KVA, any of the following may be removed of the following may be removed from service to total 3166 KVA. from service to total 2166 KVA.

11 Cond. Pump - 4000 KVA* 13 Cond. Pump - 4000 KVA 12 Cond. Pump - 4000 KVA 12 Heater Drain Pump - 1000 KVA 11 Heater Drain Pump - 1000 KVA 13 Heater Drain Pump - 1000 KVA llA Circ. Water Pump - 2000 KVA llB Circ. Water Pump - 2000 KVA 12A Circ. Water Pump - 2000 KVA 12B Circ. Water Pump - 2000 KVA 13A Cond. Pump - 4000 KVA 13B Circ. Water Pump - 2000 KVA Unit #2 21 Station Power Transformer 22 Station Power Transformer must reduce by 8166 KVA, any must reduce by 2166 KVA, any of the following may be removed of the following may be removed from service to total 8166 KVA* from service to total 2166 KVA.

11 Cond. Pump - 4000 KVA** 23 Cond. Pump - 4000 KVA 21 Cond. Pump - 4000 KVA 22 Heater Drain Pump - 1000 KVA 22 Cond. Pump - 4000 KVA 23 Heater Drain Pump - 1000 KVA 21 Heater Drain Pump - 1000 KVA 218 Circ. Water Pump - 2000 KVA 21A Circ. Wat.er Pump - 2000 KVA 22B Circ. Water Pump - 2000 KVA 22A Circ. Water Pump - 2000 KVA 238 Circ. Water Pump - 2000 KVA 23A Circ. Water Pump - 2000 KVA

  • out of service presently
    • NOTE: Unit #1 equipment

- - - - - - - - - - - - - - - - - - - - - - : - -*..... , .... ccc

.. ~-;--;:

...-;-;,,,...,,..~

ATTACHMENT 2

(

IMMEDIATE CORRECTIVE ACTIONS

1. Station electrical bus loadings will be reduced to levels consistent with those used in the Salem degraded grid voltage study performed by EG&G, Idaho, Inc. on behalf of the NRC. This condition shall be maintained until Item 1 under Long Term Corrective Actions is complete.
2. Procedures will be generated or revised as necessary to administratively control equipment removed from service in order to reach the reduced buss load levels.
3. Appropriate evaluations will be performed in accordance with the provisions of lDCFRS0.59 to justify continued operation.
4. The station electrical lineup will be shifted such that all station electrical loads are powered from the Station Power Transformers.

LONG TERM CORRECTIVE ACTIONS

1. PSE&G shall conduct a comprehensive design analysis of the Salem Generating Station electrical distribution system.

The analysis will include consideration of transients in accordance with appropriate regulatory criteria.

2. An analysis of the present protective and relaying and breaker scheme will be performed to determine the root cause of the vital bus multiple transfer phenomena and establish corrective actions to preclude recurrence.
3. Updated status reports shall be forwarded to the Regional Administrator on a monthly basis until such time as all corrective actions are complete.