ML20214X358
| ML20214X358 | |
| Person / Time | |
|---|---|
| Site: | Fort Saint Vrain  |
| Issue date: | 12/04/1986 |
| From: | Brey H PUBLIC SERVICE CO. OF COLORADO |
| To: | Berkow H Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20214X361 | List: |
| References | |
| P-86641, TAC-60400, NUDOCS 8612110084 | |
| Download: ML20214X358 (3) | |
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2420 W. 26th Avenue, Suite 1000, Denver, Colorado 80211 December 4, 1986 Fort St. Vrain Unit No. 1 P-86641 Director of Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Attention: Mr. H. N. Berkow, Director Standardization and Special Projects Directorate Docket No. 50-267
SUBJECT:
Response to Report on Chernobyl Accident
REFERENCES:
- 1) NRC letter, Heitner to Williams, dated 9/16/86 (G-86502)
- 2) PSC letter, Brey to Berkow, dated 5/9/86 (P-86358)
- 3) PSC letter, Brey to Berkow, dated 10/6/86 (P-86574)
- 4) PSC letter, Brey to Berkow, dated 10/22/86 (P-86602)
Dear Mr. Berkow:
On September 22, 1986, the Public Service Company of Colorado (PSC) received Reference 1 which transmitted the official IAEA translation of the Soviet Report on the Chernobyl Accident.
This letter requested that PSC review this translation and use it, where appropriate, to update PSC's previous report, "Chernobyl Nuclear Reactor Accident and Its Implications Upon Fort St. Vrain," dated May 9, 1986, and submitted in Reference 2.
In Reference 3, PSC committed to furnish the NRC with the areas to be investigated and a schedule for their completion by October 22, 1986.
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8612110084 861204 ADOCKOSOOg7 DR
P-86641' Paga 2 December 4, 1986 In Reference 4, PSC committed to update and submit this report to the NRC by November 26, 1986. However, this submittal was delayed in order to include the resolutions to NRC oral comments received on November 26, 1986 on this subject. The areas of this update were defined in Reference 4 to center on graphite related concerns resulting from the Chernobyl accident, including an analysis of worst case explosive air and water gas mixtures which are hypothetically assumed to accumulate in the PCRV during depressurized accident conditions, and a comparison of the reactor kinetics behavior of FSV and Chernobyl.
PSC hereby submits for your information the revised analysis of "Chernobyl Nuclear Reactor Accident and Its Implications Upon Fort St. Vrain, Revised November 26, 1986", prepared by GA Technologies and PSC. This completely replaces the original issue dated May 9,
1986.
The following major changes were made to this report:
The paper was reformatted to make its outline clearer and easier to follow.
A discussion comparing the reactor kinetics characteristics of FSV and Chernobyl was added to Section 2.0.
Continued core cooling after a Double DBA-2 accident was discussed in Section 3.0, Reactor Building temperatures and dose rates were assessed.
A new section, Section 4.0, was added to the paper. This section discusses steam ingress accidents and water gas generation. To assess PCRV structural margin, detonation of a hypothetical worst case mixture of air and water gas within the PCRV cavity was analyzed.
Based upon these evaluations, it was concluded that an accident directly comparable to the Chernobyl accident cannot occur at FSV due to fundamental design differences. Any remotely comparable accident is highly improbable, and, in case such an event should occur, the dose consequences are within 10CFR100 guidelines. The design margins of the PCRV are sufficiently large that the structure can successfully withstand a hypothetical worst case detonation of a mixture of air and water gas within the PCRV cavity.
Therefore, it is concluded that the risk to public health and safety from accidents at FSV remains small.
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P-86641 Pag 3 December 4, 1986 Should you have any questions concerning the attached analysis,
.please contact Mr. M. H. Holmes at (303).480-6960.
Very truly yours, b
H. L. Brey, Manager Nuclear Licensing and Fuels HLB /TRM:kb Attachment l
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